1
0
Fork 0
Commit Graph

1075 Commits (af1a8899d22c8acda5514999cd797d7139e47e56)

Author SHA1 Message Date
Goldwyn Rodrigues c4ce867fda Introduce md_cluster_info
md_cluster_info stores the cluster information in the MD device.

The join() is called when mddev detects it is a clustered device.
The main responsibilities are:
	1. Setup a DLM lockspace
	2. Setup all initial locks such as super block locks and bitmap lock (will come later)

The leave() clears up the lockspace and all the locks held.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 07:28:42 -06:00
Goldwyn Rodrigues edb39c9ded Introduce md_cluster_operations to handle cluster functions
This allows dynamic registering of cluster hooks.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 07:28:42 -06:00
NeilBrown 6791875e2e md: make reconfig_mutex optional for writes to md sysfs files.
Rather than using mddev_lock() to take the reconfig_mutex
when writing to any md sysfs file, we only take mddev_lock()
in the particular _store() functions that require it.
Admittedly this is most, but it isn't all.

This also allows us to remove special-case handling for new_dev_store
(in md_attr_store).

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 5c47daf6e7 md: move mddev_lock and related to md.h
The one which is not inline (mddev_unlock) gets EXPORTed.

This makes the locking available to personality modules so that it
doesn't have to be imposed upon them.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 23da422b19 md: use mddev->lock to protect updates to resync_{min,max}.
There are interdependencies between these two sysfs attributes
and whether a resync is currently running.

Rather than depending on reconfig_mutex to ensure no races when
testing these interdependencies are met, use the spinlock.
This will allow the mutex to be remove from protecting this
code in a subsequent patch.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 1b30e66f5a md: minor cleanup in safe_delay_store.
There isn't really much room for races with ->safemode_delay.
But as I am trying to clean up any racy code and will soon
be removing reconfig_mutex protection from most _store()
functions:
 - only set mddev->safemode_delay once, to ensure no code
   can see an intermediate value
 - use safemode_timer to call md_safemode_timeout() rather than
   calling it directly, to ensure it never races with itself.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 4af1a04176 md: move GET_BITMAP_FILE ioctl out from mddev_lock.
It makes more sense to report bitmap_info->file, rather than
bitmap->file (the later is only available once the array is
active).

With that change, use mddev->lock to protect bitmap_info being
set to NULL, and we can call get_bitmap_file() without taking
the mutex.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 1e594bb24d md: tidy up set_bitmap_file
1/ delay setting mddev->bitmap_info.file until 'f' looks
   usable, so we don't have to unset it.
2/ Don't allow bitmap file to be set if bitmap_info.file
   is already set.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown f4ad3d38d4 md: remove unnecessary 'buf' from get_bitmap_file.
'buf' is only used because d_path fills from the end of the
buffer instead of from the start.
We don't need a separate buf to handle that, we just need to use
memmove() to move the string to the start.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown 758bfc8abf md: remove mddev_lock from rdev_attr_show()
No rdev attributes need locking for 'show', though
state_show() might benefit from ensuring it sees a
consistent set of flags.

None even use rdev->mddev, so testing for it isn't really
needed and it certainly doesn't need to be held constant.

So improve state_show() and remove the locking.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:56 +11:00
NeilBrown b7b17c9b67 md: remove mddev_lock() from md_attr_show()
Most attributes can be read safely without any locking.
A race might lead to a slightly out-dated value, but nothing wrong.

We already have locking in some places where needed.
All that remains is can_clear_show(), behind_writes_used_show()
and action_show() which are easily fixed.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:55 +11:00
NeilBrown f97fcad38f md: remove need for mddev_lock() in md_seq_show()
The only access in md_seq_show that could suffer from races
not protected by ->lock is walking the rdev list.
This can receive sufficient protection from 'rcu'.

So use rdev_for_each_rcu() and get rid of mddev_lock().

Now reading /proc/mdstat will never block in md_seq_show.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06 09:32:55 +11:00
NeilBrown 36d091f475 md: protect ->pers changes with mddev->lock
->pers is already protected by ->reconfig_mutex, and
cannot possibly change when there are threads running or
outstanding IO.

However there are some places where we access ->pers
not in a thread or IO context, and where ->reconfig_mutex
is unnecessarily heavy-weight:  level_show and md_seq_show().

So protect all changes, and those accesses, with ->lock.
This is a step toward taking those accesses out from under
reconfig_mutex.

[Fixed missing "mddev->pers" -> "pers" conversion, thanks to
 Dan Carpenter <dan.carpenter@oracle.com>]

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:53 +11:00
NeilBrown db721d32b7 md: level_store: group all important changes into one place.
Gather all the changes that can happen atomically and might
be relevant to other code into one place.  This will
make it easier to refine the locking.

Note that this puts quite a few things between mddev_detach()
and ->free().  Enabling this was the point of some recent patches.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:53 +11:00
NeilBrown afa0f557cb md: rename ->stop to ->free
Now that the ->stop function only frees the private data,
rename is accordingly.

Also pass in the private pointer as an arg rather than using
mddev->private.  This flexibility will be useful in level_store().

Finally, don't clear ->private.  It doesn't make sense to clear
it seeing that isn't what we free, and it is no longer necessary
to clear ->private (it was some time ago before  ->to_remove was
introduced).

Setting ->to_remove in ->free() is a bit of a wart, but not a
big problem at the moment.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
NeilBrown 5aa61f427e md: split detach operation out from ->stop.
Each md personality has a 'stop' operation which does two
things:
 1/ it finalizes some aspects of the array to ensure nothing
    is accessing the ->private data
 2/ it frees the ->private data.

All the steps in '1' can apply to all arrays and so can be
performed in common code.

This is useful as in the case where we change the personality which
manages an array (in level_store()), it would be helpful to do
step 1 early, and step 2 later.

So split the 'step 1' functionality out into a new mddev_detach().

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
NeilBrown 64590f45dd md: make merge_bvec_fn more robust in face of personality changes.
There is no locking around calls to merge_bvec_fn(), so
it is possible that calls which coincide with a level (or personality)
change could go wrong.

So create a central dispatch point for these functions and use
rcu_read_lock().
If the array is suspended, reject any merge that can be rejected.
If not, we know it is safe to call the function.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
NeilBrown 5c675f83c6 md: make ->congested robust against personality changes.
There is currently no locking around calls to the 'congested'
bdi function.  If called at an awkward time while an array is
being converted from one level (or personality) to another, there
is a tiny chance of running code in an unreferenced module etc.

So add a 'congested' function to the md_personality operations
structure, and call it with appropriate locking from a central
'mddev_congested'.

When the array personality is changing the array will be 'suspended'
so no IO is processed.
If mddev_congested detects this, it simply reports that the
array is congested, which is a safe guess.
As mddev_suspend calls synchronize_rcu(), mddev_congested can
avoid races by included the whole call inside an rcu_read_lock()
region.
This require that the congested functions for all subordinate devices
can be run under rcu_lock.  Fortunately this is the case.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
NeilBrown 85572d7c75 md: rename mddev->write_lock to mddev->lock
This lock is used for (slightly) more than helping with writing
superblocks, and it will soon be extended further.  So the
name is inappropriate.

Also, the _irq variant hasn't been needed since 2.6.37 as it is
never taking from interrupt or bh context.

So:
  -rename write_lock to lock
  -document what it protects
  -remove _irq ... except in md_flush_request() as there
     is no wait_event_lock() (with no _irq).  This can be
     cleaned up after appropriate changes to wait.h.

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00
Linus Torvalds 8fd9589ced Three fixes for md
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIVAwUAVIzozznsnt1WYoG5AQKEOQ/9G31KYGhe3/Tn+Hhyy7o16+6fjOBSUN2z
 6GCGtOuHhom0Q+y4cdeAohw+eW9bJPqc9tRyRrLnVCuAkeymPP1t7fIRLGAuOHq5
 QjjX7ZwKK8urmPAFIxRFgJwrJctFEoaCQiZHk4Pcx9YcYm4paJP2liqqQ0khGPcl
 KGGjWgD3KMAG0moJzNmLMWBZevG3SLCTirPxOcDJuBkQ7KfP0e4UGVn/UYXdgF+f
 73yForADVIE/Jq/CXnsOEZa/nPTM7DIsXZAQqqFCnkUiuCvwhgfkowxhwCExx2d6
 w3+I69anD1WII1Z27bNDBgnJGR5xvdiAl6NTJ+GY1uMCo3lnV9OYpQrJxAEJP4dC
 nXILm6SVm7WLfLvVY1lJm3wZndIyWNmTcDxODGyMZhAY4RmjDHG+AZ9tcnY1pM+9
 rt0jHbmaj/ZZ5jKbGxPKBlQ3/U7EP8d4oiruOaDWCGT4sN+e2dbZVLpaWoNaBFUx
 eyUft+DEvY82ryz2Ktn/Exsx1aWk2Cy3cMl0ELq2L/2WAcjhA6gsikNmKG7tfafn
 Bd6WIGzAygATaFs4hOtFANyXqWubWi8TgLUHXNYUkJ2JooaMuSIfWrpeMNJyHHU7
 5bWTaSZqZ86Ygb6upvJqaA3olePMo1RPBsOev46TnuFT9vtfpzPRy6FlvbXfx8sK
 M5YCqNpTDTs=
 =Ar2y
 -----END PGP SIGNATURE-----

Merge tag 'md/3.19' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Three fixes for md.

   I did have a largish set of locking changes queued, but late testing
  showed they weren't quite as stable as I thought and while I fixed
  what I found, I decided it safer to delay them a release ...
  particularly as I'll be AFK for a few weeks.  So expect a larger batch
  next time :-)"

* tag 'md/3.19' of git://neil.brown.name/md:
  md: Check MD_RECOVERY_RUNNING as well as ->sync_thread.
  md: fix semicolon.cocci warnings
  md/raid5: fetch_block must fetch all the blocks handle_stripe_dirtying wants.
2014-12-14 12:13:05 -08:00
NeilBrown f851b60db0 md: Check MD_RECOVERY_RUNNING as well as ->sync_thread.
A recent change to md started the ->sync_thread from a asynchronously
from a work_queue rather than synchronously.  This means that there
can be a small window between the time when MD_RECOVERY_RUNNING is set
and when ->sync_thread is set.

So code that checks ->sync_thread might now conclude that the thread
has not been started and (because a lock is held) will not be started.
That is no longer the case.

Most of those places are best fixed by testing MD_RECOVERY_RUNNING
as well.  To make this completely reliable, we wake_up(&resync_wait)
after clearing that flag as well as after clearing ->sync_thread.

Other places are better served by flushing the relevant workqueue
to ensure that that if the sync thread was starting, it has now
started.  This is particularly best if we are about to stop the
sync thread.

Fixes: ac05f25669
Signed-off-by: NeilBrown <neilb@suse.de>
2014-12-11 10:02:10 +11:00
kbuild test robot 7d7e64f2ec md: fix semicolon.cocci warnings
drivers/md/md.c:7175:43-44: Unneeded semicolon

 Removes unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-12-03 16:07:59 +11:00
Gu Zheng 18c0b223cf md: use generic io stats accounting functions to simplify io stat accounting
Use generic io stats accounting help functions (generic_{start,end}_io_acct)
to simplify io stat accounting.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-24 08:05:16 -07:00
NeilBrown 45eaf45dfa md: Always set RECOVERY_NEEDED when clearing RECOVERY_FROZEN
md_check_recovery will skip any recovery and also clear
MD_RECOVERY_NEEDED if MD_RECOVERY_FROZEN is set.
So when we clear _FROZEN, we must set _NEEDED and ensure that
md_check_recovery gets run.
Otherwise we could miss out on something that is needed.

In particular, this can make it impossible to remove a
failed device from an array is the  'recovery-needed' processing
didn't happen.
Suitable for stable kernels since 3.13.

Cc: stable@vger.kernel.org (3.13+)
Reported-and-tested-by: Joe Lawrence <joe.lawrence@stratus.com>
Fixes: 30b8feb730
Signed-off-by: NeilBrown <neilb@suse.de>
2014-11-17 09:17:46 +11:00
NeilBrown 6c144d3164 md: move EXPORT_SYMBOL to after function in md.c
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown 2cbbca5e7c md: discard PRINT_RAID_DEBUG ioctl
All the interesting information printed by this ioctl
is provided in /proc/mdstat and/or sysfs.
So it isn't needed and isn't used and would be best if it didn't
exist.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown 403df47888 md: remove MD_BUG()
Most of the places that call this are doing so pointlessly.
A couple of the others a best replaced with WARN_ON().

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown 3adc28d85f md: clean up 'exit' labels in md_ioctl().
There are 4 labels and we only really need two.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown 326eb17d73 md: remove unnecessary test for MD_MAJOR in md_ioctl()
unknown ioctls no longer get this deep into md_ioctl since
md_ioctl_valid() was introduced in 3.14.
So remove the test and the misleading comment.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown e1960f8c5c md: don't allow "-sync" to be set for device in an active array.
If an array is active, devices can be marked 'faulty', but simply
removing the 'sync' flag is wrong.  That only makes sense
for an array which is not active (and is probably only useful
for testing anyway).

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown f72ffdd686 md: remove unwanted white space from md.c
My editor shows much of this is RED.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown ac05f25669 md: don't start resync thread directly from md thread.
The main 'md' thread is needed for processing writes, so if it blocks
write requests could be delayed.

Starting a new thread requires some GFP_KERNEL allocations and so can
wait for writes to complete.  This can deadlock.

So instead, ask a workqueue to start the sync thread.
There is no particular rush for this to happen, so any work queue
will do.

MD_RECOVERY_RUNNING is used to ensure only one thread is started.

Reported-by: BillStuff <billstuff2001@sbcglobal.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown 8b1afc3d67 md: Just use RCU when checking for overlap between arrays.
We don't really need the full mddev_lock here, and having to
drop it is messy.
RCU is enough to protect these lists.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
Chao Yu 50bd377405 md: avoid potential long delay under pers_lock
printk may cause long time lapse if value of printk_delay in sysctl is
configured large by user. If register_md_personality takes long time to print in
spinlock pers_lock, we may encounter high CPU usage rate when there are other
pers_lock competitors who may be blocked to spin.
We can avoid this condition by moving printk out of coverage of pers_lock
spinlock.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown 0638bb0e73 md: simplify export_array()
We don't really need that for_each loop, or those MD_BUGs.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown 4878e9eb88 md: discard find_rdev_nr in favour of find_rdev_nr_rcu
Having both is a waste - just use the one.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown 1967cd5616 md: use wait_event() to simplify md_super_wait()
md_super_wait is really just wait_event() open-coded.
So use the macro instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown 9ba3b7f5d0 md: be more relaxed about stopping an array which isn't started.
In general we don't allow an array to be stopped if it is in use.
However if the array hasn't really been started yet, then any
apparent use is an anomily, probably due to 'udev' or similar
having a look to see what is there.

This means that if something goes wrong while assembling an array
it cannot reliably be un-assembled - STOP_ARRAY could fail.
There is no value here, so change do_md_stop() to succeed
despite concurrent opens if the array has not yet been
activated.  i.e. if ->pers is NULL.

Reported-by: "Baldysiak, Pawel" <pawel.baldysiak@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown d66b1b395a md: don't allow bitmap file to be added to raid0/linear.
An array can only accept a bitmap if it will call bitmap_daemon_work
periodically, which means it needs a thread running.

If there is no thread, don't allow a bitmap to be added.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08 15:43:20 +10:00
Xiao Ni ac7e50a383 md: Recovery speed is wrong
When we calculate the speed of recovery, the numerator that contains
the recovery done sectors.  It's need to subtract the sectors which
don't finish recovery.

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08 12:11:25 +10:00
NeilBrown af5628f05d md: disable probing for md devices 512 and over.
The way md devices are traditionally created in the kernel
is simply to open the device with the desired major/minor number.

This can be problematic as some support tools, notably udev and
programs run by udev, can open a device just to see what is there, and
find that it has created something.  It is easy for a race to cause
udev to open an md device just after it was destroy, causing it to
suddenly re-appear.

For some time we have had an alternate way to create md devices
  echo md_somename > /sys/modules/md_mod/paramaters/new_array

This will always use a minor number of 512 or higher, which mdadm
normally avoids.
Using this makes the creation-by-opening unnecessary, but does
not disable it, so it is still there to cause problems.

This patch disable probing for devices with a major of 9 (MD_MAJOR)
and a minor of 512 and up.  This devices created by writing to
new_array cannot be re-created by opening the node in /dev.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-31 13:54:54 +10:00
NeilBrown 133d4527ea md: flush writes before starting a recovery.
When we write to a degraded array which has a bitmap, we
make sure the relevant bit in the bitmap remains set when
the write completes (so a 're-add' can quickly rebuilt a
temporarily-missing device).

If, immediately after such a write starts, we incorporate a spare,
commence recovery, and skip over the region where the write is
happening (because the 'needs recovery' flag isn't set yet),
then that write will not get to the new device.

Once the recovery finishes the new device will be trusted, but will
have incorrect data, leading to possible corruption.

We cannot set the 'needs recovery' flag when we start the write as we
do not know easily if the write will be "degraded" or not.  That
depends on details of the particular raid level and particular write
request.

This patch fixes a corruption issue of long standing and so it
suitable for any -stable kernel.  It applied correctly to 3.0 at
least and will minor editing to earlier kernels.

Reported-by: Bill <billstuff2001@sbcglobal.net>
Tested-by: Bill <billstuff2001@sbcglobal.net>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/53A518BB.60709@sbcglobal.net
Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-03 10:44:45 +10:00
NeilBrown 9bd3592032 md: make sure GET_ARRAY_INFO ioctl reports correct "clean" status
If an array has a bitmap, the when we set the "has bitmap" flag we
incorrectly clear the "is clean" flag.

"is clean" isn't really important when a bitmap is present, but it is
best to get it right anyway.

Reported-by: George Duffield <forumscollective@gmail.com>
Link: http://lkml.kernel.org/CAG__1a4MRV6gJL38XLAurtoSiD3rLBTmWpcS5HYvPpSfPR88UQ@mail.gmail.com
Fixes: 36fa30636f (v2.6.14)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-03 10:44:31 +10:00
NeilBrown 8b32bf5e37 md: md_clear_badblocks should return an error code on failure.
Julia Lawall and coccinelle report that md_clear_badblocks always
returns 0, despite appearing to have an error path.
The error path really should return an error code.  ENOSPC is
reasonably appropriate.

Reported-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:46 +10:00
NeilBrown bd8839e03b md: refuse to change shape of array if it is active but read-only
read-only arrays should not be changed.  This includes changing
the level, layout, size, or number of devices.

So reject those changes for readonly arrays.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:30 +10:00
NeilBrown 2ac295a544 md: always set MD_RECOVERY_INTR when interrupting a reshape thread.
Commit 8313b8e57f
   md: fix problem when adding device to read-only array with bitmap.

added a called to md_reap_sync_thread() which cause a reshape thread
to be interrupted (in particular, it could cause md_thread() to never even
call md_do_sync()).
However it didn't set MD_RECOVERY_INTR so ->finish_reshape() would not
know that the reshape didn't complete.

This only happens when mddev->ro is set and normally reshape threads
don't run in that situation.  But raid5 and raid10 can start a reshape
thread during "run" is the array is in the middle of a reshape.
They do this even if ->ro is set.

So it is best to set MD_RECOVERY_INTR before abortingg the
sync thread, just in case.

Though it rare for this to trigger a problem it can cause data corruption
because the reshape isn't finished properly.
So it is suitable for any stable which the offending commit was applied to.
(3.2 or later)

Fixes: 8313b8e57f
Cc: stable@vger.kernel.org (3.2+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:06 +10:00
NeilBrown 3991b31ea0 md: always set MD_RECOVERY_INTR when aborting a reshape or other "resync".
If mddev->ro is set, md_to_sync will (correctly) abort.
However in that case MD_RECOVERY_INTR isn't set.

If a RESHAPE had been requested, then ->finish_reshape() will be
called and it will think the reshape was successful even though
nothing happened.

Normally a resync will not be requested if ->ro is set, but if an
array is stopped while a reshape is on-going, then when the array is
started, the reshape will be restarted.  If the array is also set
read-only at this point, the reshape will instantly appear to success,
resulting in data corruption.

Consequently, this patch is suitable for any -stable kernel.

Cc: stable@vger.kernel.org (any)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-28 13:39:39 +10:00
NeilBrown 0f62fb220a md: avoid possible spinning md thread at shutdown.
If an md array with externally managed metadata (e.g. DDF or IMSM)
is in use, then we should not set safemode==2 at shutdown because:

1/ this is ineffective: user-space need to be involved in any 'safemode' handling,
2/ The safemode management code doesn't cope with safemode==2 on external metadata
   and md_check_recover enters an infinite loop.

Even at shutdown, an infinite-looping process can be problematic, so this
could cause shutdown to hang.

Cc: stable@vger.kernel.org (any kernel)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-06 09:49:31 +10:00
NeilBrown e2f23b606b md: avoid oops on unload if some process is in poll or select.
If md-mod is unloaded while some process is in poll() or select(),
then that process maintains a pointer to md_event_waiters, and when
the try to unlink from that list, they will oops.

The procfs infrastructure ensures that ->poll won't be called after
remove_proc_entry, but doesn't provide a wait_queue_head for us to
use, and the waitqueue code doesn't provide a way to remove all
listeners from a waitqueue.

So we need to:
 1/ make sure no further references to md_event_waiters are taken (by
    setting md_unloading)
 2/ wake up all processes currently waiting, and
 3/ wait until all those processes have disconnected from our
    wait_queue_head.

Reported-by: "majianpeng" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 14:42:34 +10:00
NeilBrown 035328c202 md/bitmap: don't abuse i_writecount for bitmap files.
md bitmap code currently tries to use i_writecount to stop any other
process from writing to out bitmap file.  But that is really an abuse
and has bit-rotted so locking is all wrong.

So discard that - root should be allowed to shoot self in foot.

Still use it in a much less intrusive way to stop the same file being
used as bitmap on two different array, and apply other checks to
ensure the file is at least vaguely usable for bitmap storage
(is regular, is open for write.  Support for ->bmap is already checked
elsewhere).

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 12:26:59 +10:00
Linus Torvalds f568849eda Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block
Pull core block IO changes from Jens Axboe:
 "The major piece in here is the immutable bio_ve series from Kent, the
  rest is fairly minor.  It was supposed to go in last round, but
  various issues pushed it to this release instead.  The pull request
  contains:

   - Various smaller blk-mq fixes from different folks.  Nothing major
     here, just minor fixes and cleanups.

   - Fix for a memory leak in the error path in the block ioctl code
     from Christian Engelmayer.

   - Header export fix from CaiZhiyong.

   - Finally the immutable biovec changes from Kent Overstreet.  This
     enables some nice future work on making arbitrarily sized bios
     possible, and splitting more efficient.  Related fixes to immutable
     bio_vecs:

        - dm-cache immutable fixup from Mike Snitzer.
        - btrfs immutable fixup from Muthu Kumar.

  - bio-integrity fix from Nic Bellinger, which is also going to stable"

* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
  xtensa: fixup simdisk driver to work with immutable bio_vecs
  block/blk-mq-cpu.c: use hotcpu_notifier()
  blk-mq: for_each_* macro correctness
  block: Fix memory leak in rw_copy_check_uvector() handling
  bio-integrity: Fix bio_integrity_verify segment start bug
  block: remove unrelated header files and export symbol
  blk-mq: uses page->list incorrectly
  blk-mq: use __smp_call_function_single directly
  btrfs: fix missing increment of bi_remaining
  Revert "block: Warn and free bio if bi_end_io is not set"
  block: Warn and free bio if bi_end_io is not set
  blk-mq: fix initializing request's start time
  block: blk-mq: don't export blk_mq_free_queue()
  block: blk-mq: make blk_sync_queue support mq
  block: blk-mq: support draining mq queue
  dm cache: increment bi_remaining when bi_end_io is restored
  block: fixup for generic bio chaining
  block: Really silence spurious compiler warnings
  block: Silence spurious compiler warnings
  block: Kill bio_pair_split()
  ...
2014-01-30 11:19:05 -08:00
Linus Torvalds 5c85121bf6 md updates for 3.14
All bug fixes, two tagged for -stable.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIVAwUAUuG8WTnsnt1WYoG5AQKW7A//V93TYUiUAG6zNUFrNZjuoXP0ym3jlpkH
 eIIFdcV7rr0Irgtd8+s9cW8Cjsbq3d/vMbFlwP1Co32mnCnFFojeKtCvM9GqkYrH
 o4Zr1nVAVYzKO4awByK3wBT9WbzEc/XlDgYQIpZExIYeZdzLOm6HyvlRbcE86Ug5
 QoGYOUlLu4LUZmFgB9zQ7JM0GACV5pS1afSObtACj2t2x5GVHNU84u+M+D8urPXO
 wnf+AIAzquh5F+8MX+DxmMEUaSzUHf8fXOM3jYVbzPI71SpaHssL4SwBn+j4I/8/
 SCSqeIh7qMSuqUy63/iHKCy5qAgNuRdL9fYlOTkpxzHm81Ddj8u7fySsApggVOa2
 yeKTkSRlsMFeu+LiGKNi/fINVxboaoYJVZ2DTNtKxSuW2VL2aPNz1Qjq4QnR3nSI
 LpaB3VeVKdMsH8Em1a8cgZWcjo5YFAcNtUnJq2fvj9VZ3SJNw4ZoKDL+l718iGao
 xIwAXMSafAHQVAAaNVFkwrea13TeOyxikY5Ra4vWfm+Fw8TzmYq5DqO0zaILwdAJ
 2FnNj2/2y3hk2K7qBcEvjjEakxPlTwzrzxZMfJDRMuQLqvrjbXiMGOnWzgl1D/9x
 4/uPjeFZLG7byxmIyg4Y83NkPgkWnRPpGK98r26pUH1UgnRF0a5aUFXQk7rsQrU6
 noRkZ9EPD8s=
 =d81E
 -----END PGP SIGNATURE-----

Merge tag 'md/3.14' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "All bug fixes, two tagged for -stable"

* tag 'md/3.14' of git://neil.brown.name/md:
  md/raid5: close recently introduced race in stripe_head management.
  md/raid5: fix long-standing problem with bitmap handling on write failure.
  md: check command validity early in md_ioctl().
  md: ensure metadata is writen after raid level change.
  md/raid10: avoid fullsync when not necessary.
  md: allow a partially recovered device to be hot-added to an array.
  md: Change handling of save_raid_disk and metadata update during recovery.
2014-01-24 17:41:50 -08:00
Nicolas Schichan cb335f88eb md: check command validity early in md_ioctl().
Verify that the cmd parameter passed to md_ioctl() is valid before
doing anything.

This fixes mddev->hold_active being set to 0 when an invalid ioctl
command is passed to md_ioctl() before the array has been configured.

Clearing mddev->hold_active in that case can lead to a livelock
situation when an invalid ioctl number is given to md_ioctl() by a
process when the mddev is currently being opened by another process:

Process 1				Process 2
---------				---------

md_alloc()
  mddev_find()
  -> returns a new mddev with
     hold_active == UNTIL_IOCTL
  add_disk()
  -> sends KOBJ_ADD uevent

					(sees KOBJ_ADD uevent for device)
                    			md_open()
                    			md_ioctl(INVALID_IOCTL)
                    			-> returns ENODEV and clears
                       			   mddev->hold_active
                    			md_release()
                      			md_put()
                      			-> deletes the mddev as
                         		   hold_active is 0

md_open()
  mddev_find()
  -> returns a newly
    allocated mddev with
    mddev->gendisk == NULL
-> returns with ERESTARTSYS
   (kernel restarts the open syscall)

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-16 08:55:00 +11:00
Linus Torvalds 1a60864fc1 md: half a dozen bug fixes for 3.13
All of these fix real bugs the people have hit, and are tagged
 for -stable.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIVAwUAUtYZqznsnt1WYoG5AQK50g//XuqVR/esIpGR+knf+1sD3Zk85Vp33kGL
 2UfbQbi40q/uLjBhJhOSkx/sYGw1Eo255vNX+yMVjYT9F+xbhI8vlLfecqx5Fk5J
 M+JH1sM7E2T79boFLoOBGSl/qppsQsPHa3p87FmFHQrrAuEMIbFiP98MnQjdSiv4
 Cu9cAR7x7njepHeMXBFiV7URaYtCHAXR9iMdkebkKIFlfND8w2QYD+LWo3SzBKs9
 jTrSBJRpXLHE+bZLOQPhAryb7nWkcT1R7N0vsVMQKcq1o6ZiRNnk/B9xNtV34hkc
 5zwTPe/d5AsV6Tsxg0dSs7xcBn/A+F5lg8fzdOhyE1F13COmB7sepjPTMPAy/oP1
 zjyPwnnWkHMDUW2usf3aqPMt+LGMofRCJHXjkqpMgIWQ96SQUY8F9PPxchkUCsx/
 A38I+vXl2jGDHh/DFSduef3sDOF6TYyKyLteJftyny96dc1RutrZSbHPdrkDz1YQ
 6zcyvpv0FexiXITrLg70FG8fnRMK91ZfHrmuzVP7tpm2TyeIfDriLhTAIXAcXHOT
 l22a1bNj4shFfztnD0CbH6nY/iJM7ov0x5+IyG5/iYbipon02MenQeV9km6JVwQb
 OCGHYCTswiFSduX1E1ru52dHXifbANWgzcUH0sjGQ0YZNmxvPRBWDjB1H2J1auzW
 J8T10qimw1w=
 =uvyl
 -----END PGP SIGNATURE-----

Merge tag 'md/3.13-fixes' of git://neil.brown.name/md

Pull late md fixes from Neil Brown:
 "Half a dozen md bug fixes.

  All of these fix real bugs the people have hit, and are tagged for
  -stable.  Sorry they are late ....  Christmas holidays and all that.
  Hopefully they can still squeak into 3.13"

* tag 'md/3.13-fixes' of git://neil.brown.name/md:
  md: fix problem when adding device to read-only array with bitmap.
  md/raid10: fix bug when raid10 recovery fails to recover a block.
  md/raid5: fix a recently broken BUG_ON().
  md/raid1: fix request counting bug in new 'barrier' code.
  md/raid10: fix two bugs in handling of known-bad-blocks.
  md/raid5: Fix possible confusion when multiple write errors occur.
2014-01-15 15:07:36 +07:00
NeilBrown 830778a180 md: ensure metadata is writen after raid level change.
level_store() currently does not make sure the metadata is
updates to reflect the new raid level.  It simply sets MD_CHANGE_DEVS.

Any level with a ->thread will quickly notice this and update the
metadata.  However RAID0 and Linear do not have a thread so no
metadata update happens until the array is stopped.  At that point the
metadata is written.

This is later that we would like.  While the delay doesn't risk any
data it can cause confusion.  So if there is no md thread, immediately
update the metadata after a level change.

Reported-by: Richard Michael <rmichael@edgeofthenet.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:21 +11:00
NeilBrown 7eb418851f md: allow a partially recovered device to be hot-added to an array.
When adding a new device into an array it is normally important to
clear any stale data from ->recovery_offset else the new device may
not be recovered properly.

However when re-adding a device which is known to be nearly in-sync,
this is not needed and can be detrimental.  The (bitmap-based)
resync will still happen, and further recovery is only needed from
where-ever it was already up to.

So if save_raid_disk is set, signifying a re-add, don't clear
->recovery_offset.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:21 +11:00
NeilBrown f466722ca6 md: Change handling of save_raid_disk and metadata update during recovery.
Since commit d70ed2e4fa
   MD: Allow restarting an interrupted incremental recovery.

we don't write out the metadata to devices while they are recovering.
This had a good reason, but has unfortunate consequences.  This patch
changes things to make them work better.

At issue is what happens if the array is shut down while a recovery is
happening, particularly a bitmap-guided recovery.
Ideally the recovery should pick up where it left off.
However the metadata cannot represent the state "A recovery is in
process which is guided by the bitmap".

Before the above mentioned commit, we wrote metadata to the device
which said "this is being recovered and it is up to <here>".  So after
a restart, a full recovery (not bitmap-guided) would happen from
where-ever it was up to.

After the commit the metadata wasn't updated so it still said "This
device is fully in sync with <this> event count".  That leads to a
bitmap-based recovery following the whole bitmap, which should be a
lot less work than a full recovery from some starting point.  So this
was an improvement.

However updates some metadata but not all leads to other problems.
In particular, the metadata written to the fully-up-to-date device
record that the array has all devices present (even though some are
recovering).  So on restart, mdadm wants to find all devices and
expects them to have current event counts.
Obviously it doesn't (some have old event counts) so (when assembling
with --incremental) it waits indefinitely for the rest of the expected
devices.

It really is wrong to not update all the metadata together.  Do that
is bound to cause confusion.
Instead, we should make it possible to record the truth in the
metadata.  i.e. we need to be able to record that a device is being
recovered based on the bitmap.
We already have a Feature flag to say that recovery is happening.  We
now add another one to say that it is a bitmap-based recovery.

With this we can remove the code that disables the write-out of
metadata on some devices.

So this patch:
 - moves the setting of 'saved_raid_disk' from add_new_disk to
   the validate_super methods.  This makes sure it is always set
   properly, both when adding a new device to an array, and when
   assembling an array from a collection of devices.
 - Adds a metadata flag MD_FEATURE_RECOVERY_BITMAP which is only
   used if MD_FEATURE_RECOVERY_OFFSET is set, and record that a
   bitmap-based recovery is allowed.
   This is only present in v1.x metadata. v0.90 doesn't support
   devices which are in the middle of recovery at all.
 - Only skips writing metadata to Faulty devices.

 - Also allows rdev state to be set to "-insync" via sysfs.
   This can be used for external-metadata arrays.  When the
   'role' is set the device is assumed to be in-sync.  If, after
   setting the role, we set the state to "-insync", the role is
   moved to saved_raid_disk which effectively says the device is
   partly in-sync with that slot and needs a bitmap recovery.

Cc: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:21 +11:00
NeilBrown 8313b8e57f md: fix problem when adding device to read-only array with bitmap.
If an array is started degraded, and then the missing device
is found it can be re-added and a minimal bitmap-based recovery
will bring it fully up-to-date.

If the array is read-only a recovery would not be allowed.
But also if the array is read-only and the missing device was
present very recently, then there could be no need for any
recovery at all, so we simply include the device in the read-only
array without any recovery.

However... if the missing device was removed a little longer ago
it could be missing some updates, but if a bitmap is present it will
be conditionally accepted pending a bitmap-based update.  We don't
currently detect this case properly and will include that old
device into the read-only array with no recovery even though it really
needs a recovery.

This patch keeps track of whether a bitmap-based-recovery is really
needed or not in the new Bitmap_sync rdev flag.  If that is set,
then the device will not be added to a read-only array.

Cc: Andrei Warkentin <andreiw@vmware.com>
Fixes: d70ed2e4fa
Cc: stable@vger.kernel.org (3.2+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:08 +11:00
Jens Axboe b28bc9b38c Linux 3.13-rc6
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJSwLfoAAoJEHm+PkMAQRiGi6QH/1U1B7lmHChDTw3jj1lfm9gA
 189Si4QJlnxFWCKHvKEL+pcaVuACU+aMGI8+KyMYK4/JfuWVjjj5fr/SvyHH2/8m
 LdSK8aHMhJ46uBS4WJ/l6v46qQa5e2vn8RKSBAyKm/h4vpt+hd6zJdoFrFai4th7
 k/TAwOAEHI5uzexUChwLlUBRTvbq4U8QUvDu+DeifC8cT63CGaaJ4qVzjOZrx1an
 eP6UXZrKDASZs7RU950i7xnFVDQu4PsjlZi25udsbeiKcZJgPqGgXz5ULf8ZH8RQ
 YCi1JOnTJRGGjyIOyLj7pyB01h7XiSM2+eMQ0S7g54F2s7gCJ58c2UwQX45vRWU=
 =/4/R
 -----END PGP SIGNATURE-----

Merge tag 'v3.13-rc6' into for-3.14/core

Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.

Fixup merge issues related to the immutable biovec changes.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Conflicts:
	block/blk-flush.c
	fs/btrfs/check-integrity.c
	fs/btrfs/extent_io.c
	fs/btrfs/scrub.c
	fs/logfs/dev_bdev.c
2013-12-31 09:51:02 -07:00
Linus Torvalds 5ee540613d Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current series. It contains:

   - A fix for a use-after-free of a request in blk-mq.  From Ming Lei

   - A fix for a blk-mq bug that could attempt to dereference a NULL rq
     if allocation failed

   - Two xen-blkfront small fixes

   - Cleanup of submit_bio_wait() type uses in the kernel, unifying
     that.  From Kent

   - A fix for 32-bit blkg_rwstat reading.  I apologize for this one
     looking mangled in the shortlog, it's entirely my fault for missing
     an empty line between the description and body of the text"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: fix use-after-free of request
  blk-mq: fix dereference of rq->mq_ctx if allocation fails
  block: xen-blkfront: Fix possible NULL ptr dereference
  xen-blkfront: Silence pfn maybe-uninitialized warning
  block: submit_bio_wait() conversions
  Update of blkg_stat and blkg_rwstat may happen in bh context
2013-12-05 15:33:27 -08:00
NeilBrown 142d44c310 md: test mddev->flags more safely in md_check_recovery.
commit 7a0a5355cb md: Don't test all of mddev->flags at once.
made most tests on mddev->flags safer, but missed one.

When
commit 260fa034ef md: avoid deadlock when dirty buffers during md_stop.
added MD_STILL_CLOSED, this caused md_check_recovery to misbehave.
It can think there is something to do but find nothing.  This can
lead to the md thread spinning during array shutdown.

https://bugzilla.kernel.org/show_bug.cgi?id=65721

Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Fixes: 260fa034ef
Cc: stable@vger.kernel.org (3.12)
Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-28 11:00:08 +11:00
Kent Overstreet c170bbb45f block: submit_bio_wait() conversions
It was being open coded in a few places.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-24 16:33:41 -07:00
Kent Overstreet 4f024f3797 block: Abstract out bvec iterator
Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchand@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peng Tao <tao.peng@emc.com>
Cc: Andy Adamson <andros@netapp.com>
Cc: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Pankaj Kumar <pankaj.km@samsung.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>6
2013-11-23 22:33:47 -08:00
Kent Overstreet 33879d4512 block: submit_bio_wait() conversions
It was being open coded in a few places.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Acked-by: NeilBrown <neilb@suse.de>
2013-11-23 22:33:38 -08:00
Linus Torvalds 6d6e352c80 md update for 3.13.
Mostly optimisations and obscure bug fixes.
  - raid5 gets less lock contention
  - raid1 gets less contention between normal-io and resync-io
    during resync.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIVAwUAUovzDznsnt1WYoG5AQJ1pQ//bDuXadoJ5dwjWjVxFOKoQ9j/9joEI0yH
 XTApD3ADKckdBc4TSLOIbCNLW1Pbe23HlOI/GjCiJ/7mePL3OwHd7Fx8Rfq3BubV
 f7NgjVwu8nwYD0OXEZsshImptEtrbYwQdy+qlKcHXcZz1MUfR+Egih3r/ouTEfEt
 FNq/6MpyN0IKSY82xP/jFZgesBucgKz/YOUIbwClxm7UiyISKvWQLBIAfLB3dyI3
 HoEdEzQX6I56Rw0mkSUG4Mk+8xx/8twxL+yqEUqfdJREWuB56Km8kl8y/e465Nk0
 ZZg6j/TrslVEwbEeVMx0syvYcaAWFZ4X2jdKfo1lI0g9beZp7H1GRF8yR1s2t/h4
 g/vb55MEN++4LPaE9ut4z7SG2yLyGkZgFTzTjyq5of+DFL0cayO7wXxbgpcD7JYf
 Doef/OSa6csKiGiJI48iQa08Bolmz9ZWzZQXhAthKfFQ9Rv+GEtIAi4kLR8EZPbu
 0/FL1ylYNUY9O7p0g+iy9Kcoc+xW36I95pPZf8pO8GFcXTjyuCCBVh/SNvFZZHPl
 3xk3aZJknAEID8VrVG2IJPkeDI8WK8YxmpU/nARCoytn07Df6Ye8jGvLdR8pL3lB
 TIZV6eRY4yciB8LtoK9Kg4XTmOMhBtjt4c3znkljp98vhOQQb/oHN+BXMGcwqvr9
 fk0KGrg31VA=
 =8RCg
 -----END PGP SIGNATURE-----

Merge tag 'md/3.13' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Mostly optimisations and obscure bug fixes.
   - raid5 gets less lock contention
   - raid1 gets less contention between normal-io and resync-io during
     resync"

* tag 'md/3.13' of git://neil.brown.name/md:
  md/raid5: Use conf->device_lock protect changing of multi-thread resources.
  md/raid5: Before freeing old multi-thread worker, it should flush them.
  md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE.
  UAPI: include <asm/byteorder.h> in linux/raid/md_p.h
  raid1: Rewrite the implementation of iobarrier.
  raid1: Add some macros to make code clearly.
  raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array.
  raid1: Add a field array_frozen to indicate whether raid in freeze state.
  md: Convert use of typedef ctl_table to struct ctl_table
  md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.
  md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
  md: fix some places where mddev_lock return value is not checked.
  raid5: Retry R5_ReadNoMerge flag when hit a read error.
  raid5: relieve lock contention in get_active_stripe()
  raid5: relieve lock contention in get_active_stripe()
  wait: add wait_event_cmd()
  md/raid5.c: add proper locking to error path of raid5_start_reshape.
  md: fix calculation of stacking limits on level change.
  raid5: Use slow_path to release stripe when mddev->thread is null
2013-11-20 13:05:25 -08:00
Joe Perches 82592c38a8 md: Convert use of typedef ctl_table to struct ctl_table
This typedef is unnecessary and should just be removed.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-19 15:19:18 +11:00
NeilBrown 30b8feb730 md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.
When raid5 recovery hits a fresh badblock, this badblock will flagged as unack
badblock until md_update_sb() is called.
But md_stop will take reconfig lock which means raid5d can't call
md_update_sb() in md_check_recovery(), the badblock will always
be unack, so raid5d thread enters an infinite loop and md_stop_write()
can never stop sync_thread. This causes deadlock.

To solve this, when STOP_ARRAY ioctl is issued and sync_thread is
running, we need set md->recovery FROZEN and INTR flags and wait for
sync_thread to stop before we (re)take reconfig lock.

This requires that raid5 reshape_request notices MD_RECOVERY_INTR
(which it probably should have noticed anyway) and stops waiting for a
metadata update in that case.

Reported-by: Jianpeng Ma <majianpeng@gmail.com>
Reported-by: Bian Yu <bianyu@kedacom.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-19 15:19:17 +11:00
NeilBrown c91abf5a35 md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
We currently use kthread_should_stop() in various places in the
sync/reshape code to abort early.
However some places set MD_RECOVERY_INTR but don't immediately call
md_reap_sync_thread() (and we will shortly get another one).
When this happens we are relying on md_check_recovery() to reap the
thread and that only happen when it finishes normally.
So MD_RECOVERY_INTR must lead to a normal finish without the
kthread_should_stop() test.

So replace all relevant tests, and be more careful when the thread is
interrupted not to acknowledge that latest step in a reshape as it may
not be fully committed yet.

Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop
so we don't wait have to wait for the speed to drop before we can abort.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-19 15:19:17 +11:00
NeilBrown 29f097c4d9 md: fix some places where mddev_lock return value is not checked.
Sometimes we need to lock and mddev and cannot cope with
failure due to interrupt.
In these cases we should use mutex_lock, not mutex_lock_interruptible.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-19 15:19:17 +11:00
NeilBrown 02e5f5c0a0 md: fix calculation of stacking limits on level change.
The various ->run routines of md personalities assume that the 'queue'
has been initialised by the blk_set_stacking_limits() call in
md_alloc().

However when the level is changed (by level_store()) the ->run routine
for the new level is called for an array which has already had the
stacking limits modified.  This can result in incorrect final
settings.

So call blk_set_stacking_limits() before ->run in level_store().

A specific consequence of this bug is that it causes
discard_granularity to be set incorrectly when reshaping a RAID4 to a
RAID0.

This is suitable for any -stable kernel since 3.3 in which
blk_set_stacking_limits() was introduced.

Cc: stable@vger.kernel.org (3.3+)
Reported-and-tested-by: "Baldysiak, Pawel" <pawel.baldysiak@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-14 15:16:15 +11:00
Linus Torvalds 0910c0bdf7 Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block
Pull block IO core updates from Jens Axboe:
 "This is the pull request for the core changes in the block layer for
  3.13.  It contains:

   - The new blk-mq request interface.

     This is a new and more scalable queueing model that marries the
     best part of the request based interface we currently have (which
     is fully featured, but scales poorly) and the bio based "interface"
     which the new drivers for high IOPS devices end up using because
     it's much faster than the request based one.

     The bio interface has no block layer support, since it taps into
     the stack much earlier.  This means that drivers end up having to
     implement a lot of functionality on their own, like tagging,
     timeout handling, requeue, etc.  The blk-mq interface provides all
     these.  Some drivers even provide a switch to select bio or rq and
     has code to handle both, since things like merging only works in
     the rq model and hence is faster for some workloads.  This is a
     huge mess.  Conversion of these drivers nets us a substantial code
     reduction.  Initial results on converting SCSI to this model even
     shows an 8x improvement on single queue devices.  So while the
     model was intended to work on the newer multiqueue devices, it has
     substantial improvements for "classic" hardware as well.  This code
     has gone through extensive testing and development, it's now ready
     to go.  A pull request is coming to convert virtio-blk to this
     model will be will be coming as well, with more drivers scheduled
     for 3.14 conversion.

   - Two blktrace fixes from Jan and Chen Gang.

   - A plug merge fix from Alireza Haghdoost.

   - Conversion of __get_cpu_var() from Christoph Lameter.

   - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven.

   - A fix for a race between request completion and the timeout
     handling from Jeff Moyer.  This is what caused the merge conflict
     with blk-mq/core, in case you are looking at that.

   - A dm stacking fix from Mike Snitzer.

   - A code consolidation fix and duplicated code removal from Kent
     Overstreet.

   - A handful of block bug fixes from Mikulas Patocka, fixing a loop
     crash and memory corruption on blk cg.

   - Elevator switch bug fix from Tomoki Sekiyama.

  A heads-up that I had to rebase this branch.  Initially the immutable
  bio_vecs had been queued up for inclusion, but a week later, it became
  clear that it wasn't fully cooked yet.  So the decision was made to
  pull this out and postpone it until 3.14.  It was a straight forward
  rebase, just pruning out the immutable series and the later fixes of
  problems with it.  The rest of the patches applied directly and no
  further changes were made"

* 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits)
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: Do not call sector_div() with a 64-bit divisor
  kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()
  block: Consolidate duplicated bio_trim() implementations
  block: Use rw_copy_check_uvector()
  block: Enable sysfs nomerge control for I/O requests in the plug list
  block: properly stack underlying max_segment_size to DM device
  elevator: acquire q->sysfs_lock in elevator_change()
  elevator: Fix a race in elevator switching and md device initialization
  block: Replace __get_cpu_var uses
  bdi: test bdi_init failure
  block: fix a probe argument to blk_register_region
  loop: fix crash if blk_alloc_queue fails
  blk-core: Fix memory corruption if blkcg_init_queue fails
  block: fix race between request completion and timeout handling
  blktrace: Send BLK_TN_PROCESS events to all running traces
  blk-mq: don't disallow request merges for req->special being set
  blk-mq: mq plug list breakage
  blk-mq: fix for flush deadlock
  ...
2013-11-14 12:08:14 +09:00
Kent Overstreet 6678d83f18 block: Consolidate duplicated bio_trim() implementations
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 09:02:31 -07:00
Linus Torvalds 0324e74534 Driver Core / sysfs patches for 3.13-rc1
Here's the big driver core / sysfs update for 3.13-rc1.
 
 There's lots of dev_groups updates for different subsystems, as they all
 get slowly migrated over to the safe versions of the attribute groups
 (removing userspace races with the creation of the sysfs files.)  Also
 in here are some kobject updates, devres expansions, and the first round
 of Tejun's sysfs reworking to enable it to be used by other subsystems
 as a backend for an in-kernel filesystem.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iEYEABECAAYFAlJ6xAMACgkQMUfUDdst+yk1kQCfcHXhfnrvFZ5J/mDP509IzhNS
 ddEAoLEWoivtBppNsgrWqXpD1vi4UMsE
 =JmVW
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...
2013-11-07 11:42:15 +09:00
Bian Yu 905b0297a9 md: avoid deadlock when md_set_badblocks.
When operate harddisk and hit errors, md_set_badblocks is called after
scsi_restart_operations which already disabled the irq. but md_set_badblocks
will call write_sequnlock_irq and enable irq. so softirq can preempt the
current thread and that may cause a deadlock. I think this situation should
use write_sequnlock_irqsave/irqrestore instead.

I met the situation and the call trace is below:
[  638.919974] BUG: spinlock recursion on CPU#0, scsi_eh_13/1010
[  638.921923]  lock: 0xffff8800d4d51fc8, .magic: dead4ead, .owner: scsi_eh_13/1010, .owner_cpu: 0
[  638.923890] CPU: 0 PID: 1010 Comm: scsi_eh_13 Not tainted 3.12.0-rc5+ #37
[  638.925844] Hardware name: To be filled by O.E.M. To be filled by O.E.M./MAHOBAY, BIOS 4.6.5 03/05/2013
[  638.927816]  ffff880037ad4640 ffff880118c03d50 ffffffff8172ff85 0000000000000007
[  638.929829]  ffff8800d4d51fc8 ffff880118c03d70 ffffffff81730030 ffff8800d4d51fc8
[  638.931848]  ffffffff81a72eb0 ffff880118c03d90 ffffffff81730056 ffff8800d4d51fc8
[  638.933884] Call Trace:
[  638.935867]  <IRQ>  [<ffffffff8172ff85>] dump_stack+0x55/0x76
[  638.937878]  [<ffffffff81730030>] spin_dump+0x8a/0x8f
[  638.939861]  [<ffffffff81730056>] spin_bug+0x21/0x26
[  638.941836]  [<ffffffff81336de4>] do_raw_spin_lock+0xa4/0xc0
[  638.943801]  [<ffffffff8173f036>] _raw_spin_lock+0x66/0x80
[  638.945747]  [<ffffffff814a73ed>] ? scsi_device_unbusy+0x9d/0xd0
[  638.947672]  [<ffffffff8173fb1b>] ? _raw_spin_unlock+0x2b/0x50
[  638.949595]  [<ffffffff814a73ed>] scsi_device_unbusy+0x9d/0xd0
[  638.951504]  [<ffffffff8149ec47>] scsi_finish_command+0x37/0xe0
[  638.953388]  [<ffffffff814a75e8>] scsi_softirq_done+0xa8/0x140
[  638.955248]  [<ffffffff8130e32b>] blk_done_softirq+0x7b/0x90
[  638.957116]  [<ffffffff8104fddd>] __do_softirq+0xfd/0x330
[  638.958987]  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.960861]  [<ffffffff8174a5cc>] call_softirq+0x1c/0x30
[  638.962724]  [<ffffffff81004c7d>] do_softirq+0x8d/0xc0
[  638.964565]  [<ffffffff8105024e>] irq_exit+0x10e/0x150
[  638.966390]  [<ffffffff8174ad4a>] smp_apic_timer_interrupt+0x4a/0x60
[  638.968223]  [<ffffffff817499af>] apic_timer_interrupt+0x6f/0x80
[  638.970079]  <EOI>  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.971899]  [<ffffffff8173fa6a>] ? _raw_spin_unlock_irq+0x3a/0x50
[  638.973691]  [<ffffffff8173fa60>] ? _raw_spin_unlock_irq+0x30/0x50
[  638.975475]  [<ffffffff81562393>] md_set_badblocks+0x1f3/0x4a0
[  638.977243]  [<ffffffff81566e07>] rdev_set_badblocks+0x27/0x80
[  638.978988]  [<ffffffffa00d97bb>] raid5_end_read_request+0x36b/0x4e0 [raid456]
[  638.980723]  [<ffffffff811b5a1d>] bio_endio+0x1d/0x40
[  638.982463]  [<ffffffff81304ff3>] req_bio_endio.isra.65+0x83/0xa0
[  638.984214]  [<ffffffff81306b9f>] blk_update_request+0x7f/0x350
[  638.985967]  [<ffffffff81306ea1>] blk_update_bidi_request+0x31/0x90
[  638.987710]  [<ffffffff813085e0>] __blk_end_bidi_request+0x20/0x50
[  638.989439]  [<ffffffff8130862f>] __blk_end_request_all+0x1f/0x30
[  638.991149]  [<ffffffff81308746>] blk_peek_request+0x106/0x250
[  638.992861]  [<ffffffff814a62a9>] ? scsi_kill_request.isra.32+0xe9/0x130
[  638.994561]  [<ffffffff814a633a>] scsi_request_fn+0x4a/0x3d0
[  638.996251]  [<ffffffff813040a7>] __blk_run_queue+0x37/0x50
[  638.997900]  [<ffffffff813045af>] blk_run_queue+0x2f/0x50
[  638.999553]  [<ffffffff814a5750>] scsi_run_queue+0xe0/0x1c0
[  639.001185]  [<ffffffff814a7721>] scsi_run_host_queues+0x21/0x40
[  639.002798]  [<ffffffff814a2e87>] scsi_restart_operations+0x177/0x200
[  639.004391]  [<ffffffff814a4fe9>] scsi_error_handler+0xc9/0xe0
[  639.005996]  [<ffffffff814a4f20>] ? scsi_unjam_host+0xd0/0xd0
[  639.007600]  [<ffffffff81072f6b>] kthread+0xdb/0xe0
[  639.009205]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
[  639.010821]  [<ffffffff81748cac>] ret_from_fork+0x7c/0xb0
[  639.012437]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170

This bug was introduce in commit  2e8ac30312
(the first time rdev_set_badblock was call from interrupt context),
so this patch is appropriate for 3.5 and subsequent kernels.

Cc: <stable@vger.kernel.org> (3.5+)
Signed-off-by: Bian Yu <bianyu@kedacom.com>
Reviewed-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 12:57:11 +11:00
Tejun Heo 388975ccca sysfs: clean up sysfs_get_dirent()
The pre-existing sysfs interfaces which take explicit namespace
argument are weird in that they place the optional @ns in front of
@name which is contrary to the established convention.  For example,
we end up forcing vast majority of sysfs_get_dirent() users to do
sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
especially as @ns and @name may be interchanged without causing
compilation warning.

This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
around sysfs_get_dirent_ns().  This makes confusions a lot less
likely.

There are other interfaces which take @ns before @name.  They'll be
updated by following patches.

This patch doesn't introduce any functional changes.

v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
    error on module builds.  Reported by build test robot.  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 15:33:18 -07:00
NeilBrown 260fa034ef md: avoid deadlock when dirty buffers during md_stop.
When the last process closes /dev/mdX sync_blockdev will be called so
that all buffers get flushed.
So if it is then opened for the STOP_ARRAY ioctl to be sent there will
be nothing to flush.

However if we open /dev/mdX in order to send the STOP_ARRAY ioctl just
moments before some other process which was writing closes their file
descriptor, then there won't be a 'last close' and the buffers might
not get flushed.

So do_md_stop() calls sync_blockdev().  However at this point it is
holding ->reconfig_mutex.  So if the array is currently 'clean' then
the writes from sync_blockdev() will not complete until the array
can be marked dirty and that won't happen until some other thread
can get ->reconfig_mutex.  So we deadlock.

We need to move the sync_blockdev() call to before we take
->reconfig_mutex.
However then some other thread could open /dev/mdX and write to it
after we call sync_blockdev() and before we actually stop the array.
This can leave dirty data in the page cache which is awkward.

So introduce new flag MD_STILL_CLOSED.  Set it before calling
sync_blockdev(), clear it if anyone does open the file, and abort the
STOP_ARRAY attempt if it gets set before we lock against further
opens.

It is still possible to get problems if you open /dev/mdX, write to
it, then issue the STOP_ARRAY ioctl.  Just don't do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:45:00 +10:00
NeilBrown 7a0a5355cb md: Don't test all of mddev->flags at once.
mddev->flags is mostly used to record if an update of the
metadata is needed.  Sometimes the whole field is tested
instead of just the important bits.  This makes it difficult
to introduce more state bits.

So replace all bare tests of mddev->flags with tests for the bits
that actually need testing.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:28:23 +10:00
Dave Jones c9ad020fec md: Fix apparent cut-and-paste error in super_90_validate
Setting a variable to itself probably wasn't the intention here.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:06:17 +10:00
NeilBrown 275c51c4e3 md: fix safe_mode buglet.
Whe we set the safe_mode_timeout to a smaller value we trigger a timeout
immediately - otherwise the small value might not be honoured.
However if the previous timeout was 0 meaning "no timeout", we didn't.
This would mean that no timeout happens until the next write completes,
which could be a long time.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:43 +10:00
NeilBrown 60559da4d8 md: don't call md_allow_write in get_bitmap_file.
There is no really need as GFP_NOIO is very likely sufficient,
and failure is not catastrophic.

Calling md_allow_write here will convert a read-auto array to
read/write which could be confusing when you are just performing
a read operation.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:32 +10:00
NeilBrown 5024c29831 md: Remove recent change which allows devices to skip recovery.
commit 7ceb17e87b
    md: Allow devices to be re-added to a read-only array.

allowed a bit more than just that.  It also allows devices to be added
to a read-write array and to end up skipping recovery.

This patch removes the offending piece of code pending a rewrite for a
subsequent release.

More specifically:
 If the array has a bitmap, then the device will still need a bitmap
 based resync ('saved_raid_disk' is set under different conditions
 is a bitmap is present).
 If the array doesn't have a bitmap, then this is correct as long as
 nothing has been written to the array since the metadata was checked
 by ->validate_super.  However there is no locking to ensure that there
 was no write.

Bug was introduced in 3.10 and causes data corruption so
patch is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:03 +10:00
Jonathan Brassow c4a3955145 MD: Remember the last sync operation that was performed
MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:24 +10:00
Jingoo Han b29bebd66d md: replace strict_strto*() with kstrto*()
The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:26 +10:00
Hannes Reinecke 90f5f7ad4f md: Wait for md_check_recovery before attempting device removal.
When a device has failed, it needs to be removed from the personality
module before it can be removed from the array as a whole.
The first step is performed by md_check_recovery() which is called
from the raid management thread.

So when a HOT_REMOVE ioctl arrives, wait briefly for md_check_recovery
to have run.  This increases the chance that the ioctl will succeed.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Neil Brown <nfbrown@suse.de>
2013-06-14 08:10:26 +10:00
Linus Torvalds 82ea4be61f A few bugfixes for md
Some tagged for -stable.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIVAwUAUbl1mznsnt1WYoG5AQKGlQ//eixdawF+DUK5hadqZ9EDni+BAVzb7m69
 +zU6ilQ7UOh7bxtAoJqrgFVykK+LG8wvYsEBwMjB9oRDLA96/YDXXiBzXHvd6mGh
 g271lwMTQ9h+O8L6psLUX6qsrH3i7SJmF8ySPKi6Fe5ruT8ToOB8Ii8XQebEZdXo
 VOzRz2VgSTcBdrTyKPDsBJByDQX36hsK8Gs5YSl5F3nvyV4dvGWMlyoTF1TRRt9K
 YCCZ8pSk3kTXaSdl0syrJxI17pEUC8mtcA01S6JD/GV49CGO8LYAckVJ4ijWw7VV
 IGGlH0DsYSMgJ7yyuLz4ifaqRnsWsAGW0WyiZYYKvjtNUiyBuBBbo2cQ1lNkR5p4
 jnLhpJJVh0hLCPn6wcCWIBIdT/mFaBpXkvZPd3ks5kefGXsfpVPm0fK8r0fzkzgy
 tJCZtZFZHeK1qsgaDsiS76S2ZNcFh0HQVIa84Q200/XUDgh8dYlD0+7oIsVu0UBZ
 72Aop+Ak9+k4vKTvB9/hpcY+Rt0MI7zKewXBDSDK1sXhIHLQqv8rCEeNYiuPPqr/
 ghRukn+C/Wtr7JYBsX+jMjxtmSzYtwBOihwLoZCH9pp3C5jTvyQk9s8n1j13V2RK
 sAFtfpCVoQ8tTa7IITKRMfftzHn1WiPlPsj6VbigJ6A4N98csgv7x2rF7FyqcF0X
 aoj69nQ3i/4=
 =8iy3
 -----END PGP SIGNATURE-----

Merge tag 'md-3.10-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "A few bugfixes for md

  Some tagged for -stable"

* tag 'md-3.10-fixes' of git://neil.brown.name/md:
  md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
  md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
  md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
  md: md_stop_writes() should always freeze recovery.
2013-06-13 10:13:29 -07:00
NeilBrown 6b6204ee92 md: md_stop_writes() should always freeze recovery.
__md_stop_writes() will currently sometimes freeze recovery.
So any caller must be ready for that to happen, and indeed they are.

However if __md_stop_writes() doesn't freeze_recovery, then
a recovery could start before mddev_suspend() is called, which
could be awkward.  This can particularly cause problems or dm-raid.

So change __md_stop_writes() to always freeze recovery.  This is safe
and more predicatable.

Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Tested-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:18:15 +10:00
Linus Torvalds 4de13d7aa8 Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block
Pull block core updates from Jens Axboe:

 - Major bit is Kents prep work for immutable bio vecs.

 - Stable candidate fix for a scheduling-while-atomic in the queue
   bypass operation.

 - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging
   discard bios.

 - Tejuns changes to convert the writeback thread pool to the generic
   workqueue mechanism.

 - Runtime PM framework, SCSI patches exists on top of these in James'
   tree.

 - A few random fixes.

* 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits)
  relay: move remove_buf_file inside relay_close_buf
  partitions/efi.c: replace useless kzalloc's by kmalloc's
  fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read()
  block: fix max discard sectors limit
  blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
  Documentation: cfq-iosched: update documentation help for cfq tunables
  writeback: expose the bdi_wq workqueue
  writeback: replace custom worker pool implementation with unbound workqueue
  writeback: remove unused bdi_pending_list
  aoe: Fix unitialized var usage
  bio-integrity: Add explicit field for owner of bip_buf
  block: Add an explicit bio flag for bios that own their bvec
  block: Add bio_alloc_pages()
  block: Convert some code to bio_for_each_segment_all()
  block: Add bio_for_each_segment_all()
  bounce: Refactor __blk_queue_bounce to not use bi_io_vec
  raid1: use bio_copy_data()
  pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
  pktcdvd: use bio_copy_data()
  block: Add bio_copy_data()
  ...
2013-05-08 10:13:35 -07:00
Al Viro db2a144bed block_device_operations->release() should return void
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-07 02:16:21 -04:00
NeilBrown 486adf72cc md: bad block list should default to disabled.
Maintenance of a bad-block-list currently defaults to 'enabled'
and is then disabled when it cannot be supported.
This is backwards and causes problem for dm-raid which didn't know
to disable it.

So fix the defaults, and only enabled for v1.x metadata which
explicitly has bad blocks enabled.

The problem with dm-raid has been present since badblock support was
added in v3.1, so this patch is suitable for any -stable from 3.1
onwards.

Cc: stable@vger.kernel.org (3.1+)
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:32 +10:00
Jonathan Brassow a91d5ac048 MD: Export 'md_reap_sync_thread' function
MD: Export 'md_reap_sync_thread' function

Make 'md_reap_sync_thread' available to other files, specifically dm-raid.c.
- rename reap_sync_thread to md_reap_sync_thread
- move the fn after md_check_recovery to match md.h declaration placement
- export md_reap_sync_thread

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:43 +10:00
NeilBrown b6d428c669 md: don't update metadata when stopping a read-only array.
read-only arrays should stay that way as much as possible.
Updating the metadata - which could be triggered by a re-add
while assembling the array metadata - should be avoided.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown 7ceb17e87b md: Allow devices to be re-added to a read-only array.
When assembling an array incrementally we might want to make
it device available when "enough" devices are present, but maybe
not "all" devices are present.
If the remaining devices appear before the array is actually used,
they should be added transparently.

We do this by using the "read-auto" mode where the array acts like
it is read-only until a write request arrives.

Current an add-device request switches a read-auto array to active.
This means that only one device can be added after the array is first
made read-auto.  This isn't a problem for RAID5, but is not ideal for
RAID6 or RAID10.
Also we don't really want to switch the array to read-auto at all
when re-adding a device as this doesn't really imply any change.

So:
 - remove the "md_update_sb()" call from add_new_disk().  This isn't
   really needed as just adding a disk doesn't require a metadata
   update.  Instead, just set MD_CHANGE_DEVS.  This will effect a
   metadata update soon enough, once the array is not read-only.

 - Allow the ADD_NEW_DISK ioctl to succeed without activating a
   read-auto array, providing the MD_DISK_SYNC flag is set.
   In this case, the device will be rejected if it cannot be added
   with the correct device number, or has an incorrect event count.

 - Teach remove_and_add_spares() to be careful about adding spares
   when the array is read-only (or read-mostly) - only add devices
   that are thought to be in-sync, and only do it if the array is
   in-sync itself.

 - In md_check_recovery, use remove_and_add_spares in the read-only
   case, rather than open coding just the 'remove' part of it.

Reported-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown 3ea8929da3 md: HOT_DISK_REMOVE shouldn't make a read-auto device active.
If a fail device or a spare is removed from an array, there is
not need to make the array 'active'.  If/when the array does become
active for some other reason the metadata will be update to reflect
the removal.
If that never happens and the array is stopped while still read-auto,
then there is no loss in forgetting the that the device had 'failed'.

A read-only array will leave failed devices attached to
the array personality, so we need to explicitly call
remove_and_add_spares() to free it (clearing Blocked just
like we do in store_slot()).

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown 746d3207ae md: use common code for all calls to ->hot_remove_disk()
slot_store and remove_and_add_spares both call ->hot_remove_disk(),
but with slightly different tests and consequences, which is
at least untidy and might be buggy.

So modify remove_and_add_spaces() so that it can be asked
to remove a specific device, and call it from slot_store().

We also clear the Blocked flag to ensure that doesn't prevent
removal.  The purpose of Blocked is to prevent automatic removal
by the kernel before an error is acknowledged.
If the array is read/write then user-space would have not reason
to remove a device unless it was known to be 'spare' or 'faulty' in
which it would have already cleared the Blocked flag.
If the array is read-only, the flag might still be blocked, but
there is no harm in clearing the flag for read-only arrays.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown d87f064f58 md: never update metadata when array is read-only.
Normally we don't even try to update the metadata if
the array is read-only.  However future patches
will increase the number of things that can happen on a read-only
array, so it is safest to explicitly disable this.

Every time that mddev->ro is set to 0, either
 - md_update_sb will be called again (at least if MD_CHANGE_DEVS
   is set) or
 - the mddev->thread is scheduled, which will also run
   md_update_sb if needed.

So this is safe: if the array ever become read-write the
metadata will be updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:40 +10:00
Jens Axboe 64f8de4da7 Merge branch 'writeback-workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into for-3.10/core
Tejun writes:

-----

This is the pull request for the earlier patchset[1] with the same
name.  It's only three patches (the first one was committed to
workqueue tree) but the merge strategy is a bit involved due to the
dependencies.

* Because the conversion needs features from wq/for-3.10,
  block/for-3.10/core is based on rc3, and wq/for-3.10 has conflicts
  with rc3, I pulled mainline (rc5) into wq/for-3.10 to prevent those
  workqueue conflicts from flaring up in block tree.

* Resolving the issue that Jan and Dave raised about debugging
  requires arch-wide changes.  The patchset is being worked on[2] but
  it'll have to go through -mm after these changes show up in -next,
  and not included in this pull request.

The three commits are located in the following git branch.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git writeback-workqueue

Pulling it into block/for-3.10/core produces a conflict in
drivers/md/raid5.c between the following two commits.

  e3620a3ad5 ("MD RAID5: Avoid accessing gendisk or queue structs when not available")
  2f6db2a707 ("raid5: use bio_reset()")

The conflict is trivial - one removes an "if ()" conditional while the
other removes "rbi->bi_next = NULL" right above it.  We just need to
remove both.  The merged branch is available at

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git block-test-merge

so that you can use it for verification.  The test merge commit has
proper merge description.

While these changes are a bit of pain to route, they make code simpler
and even have, while minute, measureable performance gain[3] even on a
workload which isn't particularly favorable to showing the benefits of
this conversion.

----

Fixed up the conflict.

Conflicts:
	drivers/md/raid5.c

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-04-02 10:04:39 +02:00
Kent Overstreet fb9e353476 md: Convert md_trim_bio() to use bio_advance()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>
2013-03-23 14:15:28 -07:00
Jonathan Brassow 90584fc93d MD: Prevent sysfs operations on uninitialized kobjects
MD: Prevent sysfs operations on uninitialized kobjects

Device-mapper does not use sysfs; but when device-mapper is leveraging
MD's RAID personalities, MD sometimes attempts to update sysfs.  This
patch adds checks for 'mddev-kobj.sd' in sysfs_[un]link_rdev to ensure
it is about to operate on something valid.  This patch also checks for
'mddev->kobj.sd' before calling 'sysfs_notify' in 'remove_and_add_spares'.
Although 'sysfs_notify' already makes this check, doing so in
'remove_and_add_spares' prevents an additional mutex operation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:17:57 +11:00
NeilBrown f3378b4870 md: expedite metadata update when switching read-auto -> active
If something has failed while the array was read-auto,
then when we switch to 'active' we need to update the metadata.
This will happen anyway but it is good to expedite it, and
also to ensure any failed device has been released by the
underlying device before we try to action the ioctl which
caused us to switch to 'active' mode.

Reported-by: Joe Lawrence <Joe.Lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-28 11:59:03 +11:00
NeilBrown a646853991 md: fix two bugs when attempting to resize RAID0 array.
You cannot resize a RAID0 array (in terms of making the devices
bigger), but the code doesn't entirely stop you.
So:

 disable setting of the available size on each device for
 RAID0 and Linear devices.  This must not change as doing so
 can change the effective layout of data.

 Make sure that the size that raid0_size() reports is accurate,
 but rounding devices sizes to chunk sizes.  As the device sizes
 cannot change now, this isn't so important, but it is best to be
 safe.

Without this change:
  mdadm --grow /dev/md0 -z max
  mdadm --grow /dev/md0 -Z max
  then read to the end of the array

can cause a BUG in a RAID0 array.

These bugs have been present ever since it became possible
to resize any device, which is a long time.  So the fix is
suitable for any -stable kerenl.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:40 +11:00
Sebastian Riemer bbfa57c0f2 md: protect against crash upon fsync on ro array
If an fsync occurs on a read-only array, we need to send a
completion for the IO and may not increment the active IO count.
Otherwise, we hit a bug trace and can't stop the MD array anymore.

By advice of Christoph Hellwig we return success upon a flush
request but we return -EROFS for other writes.
We detect flush requests by checking if the bio has zero sectors.

This patch is suitable to any -stable kernel to which it applies.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-21 13:28:09 +11:00
Linus Torvalds ea88eeac0c md update for 3.8
Mostly just little fixes.  Probably biggest part is
 AVX accelerated RAID6 calculations.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIVAwUAUM/w2Dnsnt1WYoG5AQKXlg/9F5juv4CjRkRRFLqZgOPBLmn/s/2Vspgh
 2Kv8Jcyixd8jUQNbobZv0ahlJH/iSU61kpOE8QjLbKi5Y42vAbM0ZU2aHJ6nqGZy
 HiTI8K+7kTvCK3ZXLcUQ+4oPPBNTcoTZbLWaEOmIqB1ruLddoIR7M9fG3PspVeG0
 jijnXR8IfL6mr4YDXnJkEhFrneTysVik05RkKYZKyM/9r3stAoMJ9o0/EFy3OFxb
 lO6mLEtvjVArXcnuf1RMCw2YKgki9Y4r73HCplgQsVFvcxcpsya4gFF+lRR5j7cO
 /eMYbSQ89iWEYKh1dJ9u1nofc8fX5ia71QQyO1fkO4GXRHXPVIyBgKSbe7SaL6iG
 JUMm7idUV2rZGeq3ln3k8Yor4QqHvN1n7pRKKUF+ZdsPoQ1B/TABu+qpsAdo5ZhP
 fxDsULsHrzEaxgetd4V8F2Uptca9ni43sMI8mwsvVlA0p6SOzMIyoJLC9xAZpx11
 b3H3+7Oje/fasmszBoq5B9uAlSt9XXVN4DDn2q6cX+S96JSX6jcsN1c6cJBO+ZxB
 OU6a6P5mnU6HuxU02rspe7G8BeU+ybaonErOW+GdyC4r7M/cImC0dSp0NGHK2211
 oqu0xBx/Q/ddTFwKQqa4HzR2ws09+LhKbjdqYIhCEKttIbLIAjf73ARZ19XPSRRX
 pDR/ey2CB6E=
 =uK52
 -----END PGP SIGNATURE-----

Merge tag 'md-3.8' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Mostly just little fixes.  Probably biggest part is AVX accelerated
  RAID6 calculations."

* tag 'md-3.8' of git://neil.brown.name/md:
  md/raid5: add blktrace calls
  md/raid5: use async_tx_quiesce() instead of open-coding it.
  md: Use ->curr_resync as last completed request when cleanly aborting resync.
  lib/raid6: build proper files on corresponding arch
  lib/raid6: Add AVX2 optimized gen_syndrome functions
  lib/raid6: Add AVX2 optimized recovery functions
  md: Update checkpoint of resync/recovery based on time.
  md:Add place to update ->recovery_cp.
  md.c: re-indent various 'switch' statements.
  md: close race between removing and adding a device.
  md: removed unused variable in calc_sb_1_csm.
2012-12-18 09:32:44 -08:00
Linus Torvalds 9228ff9038 Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "Now that the core bits are in, here are the driver bits for 3.8.  The
  branch contains:

   - A huge pile of drbd bits that were dumped from the 3.7 merge
     window.  Following that, it was both made perfectly clear that
     there is going to be no more over-the-wall pulls and how the
     situation on individual pulls can be improved.

   - A few cleanups from Akinobu Mita for drbd and cciss.

   - Queue improvement for loop from Lukas.  This grew into adding a
     generic interface for waiting/checking an even with a specific
     lock, allowing this to be pulled out of md and now loop and drbd is
     also using it.

   - A few fixes for xen back/front block driver from Roger Pau Monne.

   - Partition improvements from Stephen Warren, allowing partiion UUID
     to be used as an identifier."

* 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits)
  drbd: update Kconfig to match current dependencies
  drbd: Fix drbdsetup wait-connect, wait-sync etc... commands
  drbd: close race between drbd_set_role and drbd_connect
  drbd: respect no-md-barriers setting also when changed online via disk-options
  drbd: Remove obsolete check
  drbd: fixup after wait_even_lock_irq() addition to generic code
  loop: Limit the number of requests in the bio list
  wait: add wait_event_lock_irq() interface
  xen-blkfront: free allocated page
  xen-blkback: move free persistent grants code
  block: partition: msdos: provide UUIDs for partitions
  init: reduce PARTUUID min length to 1 from 36
  block: store partition_meta_info.uuid as a string
  cciss: use check_signature()
  cciss: cleanup bitops usage
  drbd: use copy_highpage
  drbd: if the replication link breaks during handshake, keep retrying
  drbd: check return of kmalloc in receive_uuids
  drbd: Broadcast sync progress no more often than once per second
  drbd: don't try to clear bits once the disk has failed
  ...
2012-12-17 13:39:11 -08:00
Linus Torvalds a2013a13e6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial branch from Jiri Kosina:
 "Usual stuff -- comment/printk typo fixes, documentation updates, dead
  code elimination."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  HOWTO: fix double words typo
  x86 mtrr: fix comment typo in mtrr_bp_init
  propagate name change to comments in kernel source
  doc: Update the name of profiling based on sysfs
  treewide: Fix typos in various drivers
  treewide: Fix typos in various Kconfig
  wireless: mwifiex: Fix typo in wireless/mwifiex driver
  messages: i2o: Fix typo in messages/i2o
  scripts/kernel-doc: check that non-void fcts describe their return value
  Kernel-doc: Convention: Use a "Return" section to describe return values
  radeon: Fix typo and copy/paste error in comments
  doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
  various: Fix spelling of "asynchronous" in comments.
  Fix misspellings of "whether" in comments.
  eisa: Fix spelling of "asynchronous".
  various: Fix spelling of "registered" in comments.
  doc: fix quite a few typos within Documentation
  target: iscsi: fix comment typos in target/iscsi drivers
  treewide: fix typo of "suport" in various comments and Kconfig
  treewide: fix typo of "suppport" in various comments
  ...
2012-12-13 12:00:02 -08:00
majianpeng 0a19caabf0 md: Use ->curr_resync as last completed request when cleanly aborting resync.
If a resync is aborted cleanly, ->curr_resync is a reliable
record of where we got up to.
If there was an error it is less reliable but we always know that
->curr_resync_completed is safe.

So add a flag MD_RECOVERY_ERROR to differentiate between these cases
and set recovery_cp accordingly.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 19:52:11 +11:00
majianpeng 54f89341e8 md: Update checkpoint of resync/recovery based on time.
md will current only only checkpoint recovery or resync ever 1/16th
of the device size.  As devices get larger this can become a long time
an so a lot of work that might need to be duplicated after a shutdown.

So add a time-based checkpoint.  Every 5 minutes limits the amount of
duplicated effort to at most 5 minutes, and has almost zero impact on
performance.

[changelog entry re-written by NeilBrown]

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 16:41:40 +11:00
kernelmail 35d78c6696 md:Add place to update ->recovery_cp.
In resyncing, recovery_cp only updated when resync aborted or completed.
But in md drives,many place used it to judge.So add a place to update.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 16:41:01 +11:00
NeilBrown c02c0aeb6c md.c: re-indent various 'switch' statements.
Intent was unnecessarily deep.

Also change one 'switch' which has a single case element, into an
'if'.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-11 13:39:21 +11:00
NeilBrown a7a3f08dc2 md: close race between removing and adding a device.
When we remove a device from an md array, the final removal of
the "dev-XX" sys entry is run asynchronously.
If we then re-add that device immediately before the worker thread
gets to run, we can end up trying to add the "dev-XX" sysfs entry back
before it has been removed.

So in both places where we add a device, call
  flush_workqueue(md_misc_wq);
before taking the md lock (as holding the md lock can prevent removal
to complete).

Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-11 13:35:54 +11:00
NeilBrown 1f3c9907b8 md: removed unused variable in calc_sb_1_csm.
'i' is unused.

NeilBrown <neilb@suse.de>
2012-12-11 13:09:00 +11:00
Lukas Czerner eed8c02e68 wait: add wait_event_lock_irq() interface
New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit
moves the private wait_event_lock_irq() macro from MD to regular wait
includes, introduces new macro wait_event_lock_irq_cmd() instead of using
the old method with omitting cmd parameter which is ugly and makes a use
of new macros in the MD. It also introduces the _interruptible_ variant.

The use of new interface is when one have a special lock to protect data
structures used in the condition, or one also needs to invoke "cmd"
before putting it to sleep.

All new macros are expected to be called with the lock taken. The lock
is released before sleep and is reacquired afterwards. We will leave the
macro with the lock held.

Note to DM: IMO this should also fix theoretical race on waitqueue while
using simultaneously wait_event_lock_irq() and wait_event() because of
lack of locking around current state setting and wait queue removal.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-30 11:47:57 +01:00
NeilBrown 5eff3c439d md: make sure everything is freed when dm-raid stops an array.
md_stop() would stop an array, but not free various attached
data structures.
For internal arrays, these are freed later in do_md_stop() or
mddev_put(), but they don't apply for dm-raid arrays.
So get md_stop() to free them, and only all it from dm-raid.
For internal arrays we now call __md_stop.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:37 +11:00
majianpeng 35f9ac2dce md: Avoid write invalid address if read_seqretry returned true.
If read_seqretry returned true and bbp was changed, it will write
invalid address which can cause some serious problem.

This bug was introduced by commit v3.0-rc7-130-g2699b67.
So fix is suitable for 3.0.y thru 3.6.y.

Reported-by: zhuwenfeng@kedacom.com
Tested-by: zhuwenfeng@kedacom.com
Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:17 +11:00
majianpeng ab05613a06 md: Reassigned the parameters if read_seqretry returned true in func md_is_badblock.
This bug was introduced by commit(v3.0-rc7-126-g2230dfe).
So fix is suitable for 3.0.y thru 3.6.y.

Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:05 +11:00
Masanari Iida 83f0d77a7f md: Fix typo in drivers/md
Correct spelling typo in drivers/md.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-29 22:57:50 +01:00
Linus Torvalds 9db908806b md updates for 3.7
"discard" support, some dm-raid improvements and other assorted
 bits and pieces.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIVAwUAUHk6Rjnsnt1WYoG5AQKovQ//Ym0ROo5a6uekb2USLyFSdQH3TC7z0v0+
 +kujrgoc4nHZU/vj5yfMvPVomEUsAhHEwTkvvCiXFFHn6cxPzC8ezm8d40xEeISX
 qp6i2bPlvGURhsW1tYeD+THtY82/oyzQ4Wa/vaE1sjVLQ+caa2q7kVVgAL9Bj/Kz
 aESIZjAuPxQNE1674/KR0EmMFcbpd0z1WDV+ydKlRV5jHCHGYf8OmxOenJFf+V/b
 /f9p2u+NUq5BN5WLhThcysO8lPX1Y7GG8IYay3DlSt/crU24R2a2j0qh/BDoK8+t
 /DceoHipbIiGxXLVjM7y+1RwPpCh75HJSZQHltPype2Z3iwtwEth9uTkEE3M2h/W
 tOQEbOZku0kcgsrys7JBmpkBwkR9oZqq1kDd4YBzqW4PiGVP6z0JRH8QpjjB+mjN
 47ODYIZcaEYZ+0Jj8kcVxo3gv4Xj4DWH+auSNZihTVmjQPVqrcy3CAt3CkuDzTkY
 34fZVuCDiCetLGCGQKrwfMDnySVy5xOmtC6iWsEY5rExAeb0E+BCzcBvbAXzt+ef
 MPDsrxWbo/ZkvpuwXOwLFTccBuRtAsFi7CM4jcow53W6XMnPpdubphNw5nylaEm1
 DEzfID58mv8VHWRuW15vr7SbtROjYJkEFCIaEK3oprrRUYftZntIABcknqvcIYR+
 /ULNzkRU1w4=
 =XRmL
 -----END PGP SIGNATURE-----

Merge tag 'md-3.7' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 - "discard" support, some dm-raid improvements and other assorted bits
   and pieces.

* tag 'md-3.7' of git://neil.brown.name/md: (29 commits)
  md: refine reporting of resync/reshape delays.
  md/raid5: be careful not to resize_stripes too big.
  md: make sure manual changes to recovery checkpoint are saved.
  md/raid10: use correct limit variable
  md: writing to sync_action should clear the read-auto state.
  Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
  md/raid5: make sure to_read and to_write never go negative.
  md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write.
  md/raid5: protect debug message against NULL derefernce.
  md/raid5: add some missing locking in handle_failed_stripe.
  MD: raid5 avoid unnecessary zero page for trim
  MD: raid5 trim support
  md/bitmap:Don't use IS_ERR to judge alloc_page().
  md/raid1: Don't release reference to device while handling read error.
  raid: replace list_for_each_continue_rcu with new interface
  add further __init annotations to crypto/xor.c
  DM RAID: Fix for "sync" directive ineffectiveness
  DM RAID: Fix comparison of index and quantity for "rebuild" parameter
  DM RAID: Add rebuild capability for RAID10
  DM RAID: Move 'rebuild' checking code to its own function
  ...
2012-10-13 13:22:01 -07:00
NeilBrown 72f36d5972 md: refine reporting of resync/reshape delays.
If 'resync_max' is set to 0 (as is often done when starting a
reshape, so the mdadm can remain in control during a sensitive
period), and if the reshape request is initially delayed because
another array using the same array is resyncing or reshaping etc,
when user-space cannot easily tell when the delay changes from being
due to a conflicting reshape, to being due to resync_max = 0.

So introduce a new state: (curr_resync == 3) to reflect this, make
sure it is visible both via /proc/mdstat and via the "sync_completed"
sysfs attribute, and ensure that the event transition from one delay
state to the other is properly notified.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:25:57 +11:00
NeilBrown db07d85ef6 md: make sure manual changes to recovery checkpoint are saved.
If you make an array bigger but suppress resync of the new region with
  mdadm --grow /dev/mdX --size=max --assume-clean

then stop the array before anything is written to it, the effect of
the "--assume-clean" is lost and the array will resync the new space
when restarted.
So ensure that we update the metadata in the case.

Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:22:17 +11:00
NeilBrown 48c26ddc9f md: writing to sync_action should clear the read-auto state.
In some cases array are started in 'read-auto' state where in
nothing gets written to any device until the array is written
to.  The purpose of this is to make accidental auto-assembly
of the wrong arrays less of a risk, and to allow arrays to be
started to read suspend-to-disk images without actually changing
anything (as might happen if the array were dirty and a
resync seemed necessary).

Explicitly writing the 'sync_action' for a read-auto array currently
doesn't clear the read-auto state, so the sync action doesn't
happen, which can be confusing.

So allow any successful write to sync_action to clear any read-auto
state.

Reported-by: Alexander Kühn <alexander.kuehn@nagilum.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:19:39 +11:00
Jianpeng Ma 7f7583d420 Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
Now that multiple threads can handle stripes, it is safer to
use an atomic64_t for resync_mismatches, to avoid update races.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:17:59 +11:00
Jonathan Brassow 2863b9eb44 MD RAID10: Prep for DM RAID10 device replacement capability
MD RAID10:  Fix a couple potential kernel panics if RAID10 is used by dm-raid

When device-mapper uses the RAID10 personality through dm-raid.c, there is no
'gendisk' structure in mddev and some sysfs information is also not populated.

This patch avoids touching those non-existent structures.

Signed-off-by: Jonathan Brassow <jbrassow@rehdat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:38:58 +11:00
NeilBrown 1ca69c4bc4 md: avoid taking the mutex on some ioctls.
Some ioctls don't need to take the mutex and doing so can cause
a delay as it is held during super-block update.
So move those ioctls out of the mutex and rely on rcu locking
to ensure we don't access stale data.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:37:33 +11:00
Shaohua Li 4ed8731d8e MD: change the parameter of md thread
Change the thread parameter, so the thread can carry extra info. Next patch
will use it.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:34:00 +11:00
Linus Torvalds ce40be7a82 Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-block
Pull block IO update from Jens Axboe:
 "Core block IO bits for 3.7.  Not a huge round this time, it contains:

   - First series from Kent cleaning up and generalizing bio allocation
     and freeing.

   - WRITE_SAME support from Martin.

   - Mikulas patches to prevent O_DIRECT crashes when someone changes
     the block size of a device.

   - Make bio_split() work on data-less bio's (like trim/discards).

   - A few other minor fixups."

Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew
Morton.  It is due to the VM no longer using a prio-tree (see commit
6b2dbba8b6ac: "mm: replace vma prio_tree with an interval tree").

So make set_blocksize() use mapping_mapped() instead of open-coding the
internal VM knowledge that has changed.

* 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits)
  block: makes bio_split support bio without data
  scatterlist: refactor the sg_nents
  scatterlist: add sg_nents
  fs: fix include/percpu-rwsem.h export error
  percpu-rw-semaphore: fix documentation typos
  fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared
  blockdev: turn a rw semaphore into a percpu rw semaphore
  Fix a crash when block device is read and block size is changed at the same time
  block: fix request_queue->flags initialization
  block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue()
  block: ioctl to zero block ranges
  block: Make blkdev_issue_zeroout use WRITE SAME
  block: Implement support for WRITE SAME
  block: Consolidate command flag and queue limit checks for merges
  block: Clean up special command handling logic
  block/blk-tag.c: Remove useless kfree
  block: remove the duplicated setting for congestion_threshold
  block: reject invalid queue attribute values
  block: Add bio_clone_bioset(), bio_clone_kmalloc()
  block: Consolidate bio_alloc_bioset(), bio_kmalloc()
  ...
2012-10-11 09:04:23 +09:00
NeilBrown 6dafab6b13 md: make sure metadata is updated when spares are activated or removed.
It isn't always necessary to update the metadata when spares are
removed as the presence-or-not of a spare isn't really important to
the integrity of an array.
Also activating a spare doesn't always require updating the metadata
as the update on 'recovery-completed' is usually sufficient.

However the introduction of 'replacement' devices have made these
transitions sometimes more important.  For example the 'Replacement'
flag isn't cleared until the original device is removed, so we need
to ensure a metadata update after that 'spare' is removed.

So set MD_CHANGE_DEVS whenever a spare is activated or removed, to
complement the current situation where it is set when a spare is added
or a device is failed (or a number of other less common situations).

This is suitable for -stable as out-of-data metadata could lead
to data corruption.
This is only relevant for 3.3 and later 9when 'replacement' as
introduced.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19 12:54:22 +10:00
Kent Overstreet bf800ef181 block: Add bio_clone_bioset(), bio_clone_kmalloc()
Previously, there was bio_clone() but it only allocated from the fs bio
set; as a result various users were open coding it and using
__bio_clone().

This changes bio_clone() to become bio_clone_bioset(), and then we add
bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of
the functionality the last patch adedd.

This will also help in a later patch changing how bio cloning works.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Boaz Harrosh <bharrosh@panasas.com>
CC: Jeff Garzik <jeff@garzik.org>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:39 +02:00
Kent Overstreet 1e2a410ff7 block: Ues bi_pool for bio_integrity_alloc()
Now that bios keep track of where they were allocated from,
bio_integrity_alloc_bioset() becomes redundant.

Remove bio_integrity_alloc_bioset() and drop bio_set argument from the
related functions and make them use bio->bi_pool.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:38 +02:00
Kent Overstreet 395c72a707 block: Generalized bio pool freeing
With the old code, when you allocate a bio from a bio pool you have to
implement your own destructor that knows how to find the bio pool the
bio was originally allocated from.

This adds a new field to struct bio (bi_pool) and changes
bio_alloc_bioset() to use it. This makes various bio destructors
unnecessary, so they're then deleted.

v6: Explain the temporary if statement in bio_put

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Nicholas Bellinger <nab@linux-iscsi.org>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:38 +02:00
NeilBrown 667a5313ec md: Don't truncate size at 4TB for RAID0 and Linear
commit 27a7b260f7
   md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.

changed 0.90 metadata handling to truncated size to 4TB as that is
all that 0.90 can record.
However for RAID0 and Linear, 0.90 doesn't need to record the size, so
this truncation is not needed and causes working arrays to become too small.

So avoid the truncation for RAID0 and Linear

This bug was introduced in 3.1 and is suitable for any stable kernels
from then onwards.
As the offending commit was tagged for 'stable', any stable kernel
that it was applied to should also get this patch.  That includes
at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for
providing that list).

Cc: stable@vger.kernel.org
Signed-off-by: Neil Brown <neilb@suse.de>
2012-08-16 16:46:12 +10:00
Linus Torvalds eff0d13f38 Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:

 - Making the plugging support for drivers a bit more sane from Neil.
   This supersedes the plugging change from Shaohua as well.

 - The usual round of drbd updates.

 - Using a tail add instead of a head add in the request completion for
   ndb, making us find the most completed request more quickly.

 - A few floppy changes, getting rid of a duplicated flag and also
   running the floppy init async (since it takes forever in boot terms)
   from Andi.

* 'for-3.6/drivers' of git://git.kernel.dk/linux-block:
  floppy: remove duplicated flag FD_RAW_NEED_DISK
  blk: pass from_schedule to non-request unplug functions.
  block: stack unplug
  blk: centralize non-request unplug handling.
  md: remove plug_cnt feature of plugging.
  block/nbd: micro-optimization in nbd request completion
  drbd: announce FLUSH/FUA capability to upper layers
  drbd: fix max_bio_size to be unsigned
  drbd: flush drbd work queue before invalidate/invalidate remote
  drbd: fix potential access after free
  drbd: call local-io-error handler early
  drbd: do not reset rs_pending_cnt too early
  drbd: reset congestion information before reporting it in /proc/drbd
  drbd: report congestion if we are waiting for some userland callback
  drbd: differentiate between normal and forced detach
  drbd: cleanup, remove two unused global flags
  floppy: Run floppy initialization asynchronous
2012-08-01 09:06:47 -07:00
NeilBrown 74018dc306 blk: pass from_schedule to non-request unplug functions.
This will allow md/raid to know why the unplug was called,
and will be able to act according - if !from_schedule it
is safe to perform tasks which could themselves schedule.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:15 +02:00
NeilBrown 9cbb175088 blk: centralize non-request unplug handling.
Both md and umem has similar code for getting notified on an
blk_finish_plug event.
Centralize this code in block/ and allow each driver to
provide its distinctive difference.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:14 +02:00
NeilBrown 0021b7bc04 md: remove plug_cnt feature of plugging.
This seemed like a good idea at the time, but after further thought I
cannot see it making a difference other than very occasionally and
testing to try to exercise the case it is most likely to help did not
show any performance difference by removing it.

So remove the counting of active plugs and allow 'pending writes' to
be activated at any time, not just when no plugs are active.

This is only relevant when there is a write-intent bitmap, and the
updating of the bitmap will likely introduce enough delay that
the single-threading of bitmap updates will be enough to collect large
numbers of updates together.

Removing this will make it easier to centralise the unplug code, and
will clear the other for other unplug enhancements which have a
measurable effect.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:14 +02:00
NeilBrown 90cf195d9b md: remove duplicated test on ->openers when calling do_md_stop()
do_md_stop tests mddev->openers while holding ->open_mutex,
and fails if this count is too high.
So callers do not need to check mddev->openers and doing so isn't
very meaningful as they don't hold ->open_mutex so the number could
change.

So remove the unnecessary tests on mddev->openers.
These are not called often enough for there to be any gain in
an early test on ->open_mutex to avoid the need for a slightly more
costly mutex_lock call.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:04:55 +10:00
NeilBrown a05b7ea03d md: avoid crash when stopping md array races with closing other open fds.
md will refuse to stop an array if any other fd (or mounted fs) is
using it.
When any fs is unmounted of when the last open fd is closed all
pending IO will be flushed (e.g. sync_blockdev call in __blkdev_put)
so there will be no pending IO to worry about when the array is
stopped.

However in order to send the STOP_ARRAY ioctl to stop the array one
must first get and open fd on the block device.
If some fd is being used to write to the block device and it is closed
after mdadm open the block device, but before mdadm issues the
STOP_ARRAY ioctl, then there will be no last-close on the md device so
__blkdev_put will not call sync_blockdev.

If this happens, then IO can still be in-flight while md tears down
the array and bad things can happen (use-after-free and subsequent
havoc).

So in the case where do_md_stop is being called from an open file
descriptor, call sync_block after taking the mutex to ensure there
will be no new openers.

This is needed when setting a read-write device to read-only too.

Cc: stable@vger.kernel.org
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 15:59:18 +10:00
NeilBrown 25f7fd470b md: fix bug in handling of new_data_offset
commit c6563a8c38
    md: add possibility to change data-offset for devices.

introduced a 'new_data_offset' attribute which should normally
be the same as 'data_offset', but can be explicitly set to a different
value to allow a reshape operation to move the data.

Unfortunately when the 'data_offset' is explicitly set through
sysfs, the new_data_offset is not also set, so the two would become
out-of-sync incorrectly.

One result of this is that trying to set the 'size' after the
'data_offset' would fail because it is not permitted to set the size
when the 'data_offset' and 'new_data_offset' are different - as that
can be confusing.
Consequently when mdadm tried to do this while assembling an IMSM
array it would fail.

This bug was introduced in 3.5-rc1.

Reported-by: Brian Downing <bdowning@lavos.net>
Bisected-by: Brian Downing <bdowning@lavos.net>
Tested-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 15:59:18 +10:00
NeilBrown f456309106 md: support re-add of recovering devices.
We currently only allow a device to be re-added if it appear to be
in-sync.  This is overly restrictive as it may be desirable to re-add
a device that is in the middle of recovery.

So remove the test for "InSync" - the test on rdev->raid_disk is
sufficient to ensure that the re-add will succeed.

Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:59:06 +10:00
NeilBrown 0232605d98 md: make 'name' arg to md_register_thread non-optional.
Having the 'name' arg optional and defaulting to the current
personality name is no necessary and leads to errors, as when
changing the level of an array we can end up using the
name of the old level instead of the new one.

So make it non-optional and always explicitly pass the name
of the level that the array will be.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:56:52 +10:00
majianpeng 7c2c57c9a9 md:Add blk_plug in sync_thread.
Add blk_plug in sync_thread will increase the performance of sync.
Because sync_thread did not blk_plug,so when raid sync, the bio merge
not well.

Testing environment:
SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI
Controller.
OS:Linux xxx 3.5.0-rc2+ #340 SMP Tue Jun 12 09:00:25 CST 2012
x86_64 x86_64 x86_64 GNU/Linux.
RAID5: four ST31000524NS disk.

Without blk_plug:recovery speed about 63M/Sec;
Add blk_plug:recovery speed about 120M/Sec.

Using blktrace:
blktrace -d /dev/sdb -w 60  -o -|blkparse -i -

without blk_plug:
Total (8,16):
 Reads Queued:      309811,     1239MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:   283583,     1189MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:   273351,     1149MiB	 Writes Completed:        0,        0KiB
 Read Merges:        23533,    94132KiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:           0

add blk_plug:
Total (8,16):
 Reads Queued:      428697,     1714MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:     3954,     1714MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:     3956,     1715MiB	 Writes Completed:        0,        0KiB
 Read Merges:       424743,     1698MiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:        3384

The ratio of merge will be markedly increased.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 12:12:26 +10:00
Yuanhan Liu 0c098220e2 md: check the return of mddev_find()
Check the return of mddev_find(), since it may fail due to out of
memeory or out of usable minor number.

The reason I chose -ENODEV instead of -ENOMEM or something else is
md_alloc() function chose that ;)

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:32 +10:00
Jonathan Brassow 47525e59e4 DM RAID: Set recovery flags on resume
Properly initialize MD recovery flags when resuming device-mapper devices.

When a device-mapper device is suspended, all I/O must stop.  This is done by
calling 'md_stop_writes' and 'mddev_suspend'.  These calls in-turn manipulate
the recovery flags - including setting 'MD_RECOVERY_FROZEN'.  The DM device
may have been suspended while recovery was not yet complete, so the process
needs to pick-up where it left off.  Since 'mddev_resume' does not unset
'MD_RECOVERY_FROZEN' and set 'MD_RECOVERY_NEEDED', we must do it ourselves.
'MD_RECOVERY_NEEDED' can safely be set in 'mddev_resume', but 'MD_RECOVERY_FROZEN'
must be set outside of 'mddev_resume' due to how MD handles RAID reshaping.
(e.g.  It is possible for a user to delay reshaping a RAID5->RAID6 by purposefully
setting 'MD_RECOVERY_FROZEN'.  Clearing it in 'mddev_resume' would override the
desired behavior.)

Because 'mddev_resume' already unconditionally calls 'md_wakeup_thread(mddev->thread)'
there is no need to make this call from 'raid_resume' since it calls 'mddev_resume'.

Also clean up where  level_store calls mddev_resume() - it current
duplicates some of the funcitons of that call. - NB

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:29 +10:00
NeilBrown a4a6125a07 md: allow array to be resized while bitmap is present.
Now that bitmaps can be resized, we can allow an array to be resized
while the bitmap is present.

This only covers resizing that involves changing the effective size
of member devices, not resizing that changes the number of devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:27 +10:00
NeilBrown 1ec885cdd0 md/bitmap: move some fields of 'struct bitmap' into a 'storage' substruct.
This new 'struct bitmap_storage' reflects the external storage of the
bitmap.
Having this clearly defined will make it easier to change the storage
used while the array is active.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:10 +10:00
NeilBrown ef99bf480d md/bitmap: allow a bitmap with no backing storage.
An md bitmap comprises two parts
 - internal counting of active writes per 'chunk'.
 - external storage of whether there are any active writes on
   each chunk

The second requires the first, but the first doesn't require the
second.

Not having backing storage means that the bitmap cannot expedite
resync after a crash, but it still allows us to expedite the recovery
of a recently-removed device.

So: allow a bitmap to exist even if there is no backing device.
In that case we default to 128M chunks.

A particular value of this is that we can remove and re-add a bitmap
(possibly of a different granularity) on a degraded array, and not
lose the information needed to fast-recover the missing device.

We don't actually activate these bitmaps yet - that will come
in a later patch.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:08 +10:00
NeilBrown 6409bb05a9 md/bitmap: add new 'space' attribute for bitmaps.
If we are to allow bitmaps to be resized when the array is resized,
we need to know how much space there is.

So create an attribute to store this information and set appropriate
defaults.

It can be set more precisely via sysfs, or future metadata extensions
may allow it to be recorded.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:07 +10:00
NeilBrown 4fa2f32768 md: move freeing of badblocks.page into md_rdev_clear
This ensures that it is always freed - there were case where
we failed to free the page.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:01 +10:00
NeilBrown 545c87957f md: dm-raid should call helper function to clear rdev.
dm-raid currently open-codes the freeing of some members of
and rdev.  It is more maintainable to have it call common code
from md.c which does this for all call-sites.

So remove free_disk_sb to md_rdev_clear, export it, and use it in
dm-raid.c

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:54:30 +10:00
NeilBrown c804cdecea md: use resync_max_sectors for reshape as well as resync.
Some resync type operations need to act on the address space of the
device, others on the address space of the array.

This only affects RAID10, so it sets resync_max_sectors to the array
size (it defaults to the device size), and that is currently used for
resync only.  However reshape of a RAID10 must be done against the
array size, not device size, so change code to use resync_max_sectors
for both the resync and the reshape cases.
This does not affect RAID5 or RAID1, just RAID10.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:33 +10:00
NeilBrown 1fdd6fc92f md: teach sync_page_io about new_data_offset.
Some code in raid1 and raid10 use sync_page_io to
read/write pages when responding to read errors.
As we will shortly support changing data_offset for
raid10, this function must understand new_data_offset.

So add that understanding.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:32 +10:00
NeilBrown c6563a8c38 md: add possibility to change data-offset for devices.
When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).

So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.

(As we didn't previous check that all 'pad' fields were zero,
 we need a new FEATURE flag for this.
 A (belatedly) check that all remaining 'pad' fields are
 zero to avoid a repeat of this)

The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.

This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be.  At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.

When a reshape finishes we will need to update the data_offset
and rdev->sectors.  So provide an exported function to do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:00 +10:00
NeilBrown 2c810cddc4 md: allow a reshape operation to be reversed.
Currently a reshape operation always progresses from the start
of the array to the end unless the number of devices is being
reduced, in which case it progressed in the opposite direction.

To reverse a partial reshape which changes the number of devices
you can stop the array and re-assemble with the raid-disks numbers
reversed and it will undo.

However for a reshape that does not change the number of devices
it is not possible to reverse the reshape in the middle - you have to
wait until it completes.

So add a 'reshape_direction' attribute with is either 'forwards' or
'backwards' and can be explicitly set when delta_disks is zero.

This will become more important when we allow the data_offset to
change in a reshape.  Then the explicit statement of what direction is
being used will be more useful.

This can be enabled in raid5 trivially as it already supports
reverse reshape and just needs to use a different trigger to request it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:00 +10:00
Shaohua Li b5e1b8cee7 md: using GFP_NOIO to allocate bio for flush request
A flush request is usually issued in transaction commit code path, so
using GFP_KERNEL to allocate memory for flush request bio falls into
the classic deadlock issue.

This is suitable for any -stable kernel to which it applies as it
avoids a possible deadlock.

Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:26:59 +10:00
Jonathan Brassow 0d9f4f135e MD: Add del_timer_sync to mddev_suspend (fix nasty panic)
Use del_timer_sync to remove timer before mddev_suspend finishes.

We don't want a timer going off after an mddev_suspend is called.  This is
especially true with device-mapper, since it can call the destructor function
immediately following a suspend.  This results in the removal (kfree) of the
structures upon which the timer depends - resulting in a very ugly panic.
Therefore, we add a del_timer_sync to mddev_suspend to prevent this.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-17 10:38:24 +10:00
NeilBrown 30b8aa9172 md: fix possible corruption of array metadata on shutdown.
commit c744a65c1e
  md: don't set md arrays to readonly on shutdown.

removed the possibility of a 'BUG' when data is written to an array
that has just been switched to read-only, but also introduced the
possibility that the array metadata could be corrupted.

If, when md_notify_reboot gets the mddev lock, the array is
in a state where it is assembled but hasn't been started (as can
happen if the personality module is not available, or in other unusual
situations), then incorrect metadata will be written out making it
impossible to re-assemble the array.

So only call __md_stop_writes() if the array has actually been
activated.

This patch is needed for any stable kernel which has had the above
commit applied.

Cc: stable@vger.kernel.org
Reported-by: Christoph Nelles <evilazrael@evilazrael.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-24 10:23:16 +10:00
NeilBrown ed209584c3 md: don't call ->add_disk unless there is good reason.
Commit 7bfec5f35c

   md/raid5: If there is a spare and a want_replacement device, start replacement.

cause md_check_recovery to call ->add_disk much more often.
Instead of only when the array is degraded, it is now called whenever
md_check_recovery finds anything useful to do, which includes
updating the metadata for clean<->dirty transition.
This causes unnecessary work, and causes info messages from ->add_disk
to be reported much too often.

So refine md_check_recovery to only do any actual recovery checking
(including ->add_disk) if MD_RECOVERY_NEEDED is set.

This fix is suitable for 3.3.y:

Cc: stable@vger.kernel.org
Reported-by: Jan Ceuleers <jan.ceuleers@computer.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-24 10:23:14 +10:00
majianpeng ecb178bb2b md: Add judgement bb->unacked_exist in function md_ack_all_badblocks().
If there are no unacked bad blocks, then there is no point searching
for them to acknowledge them.


Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:42 +11:00
NeilBrown d0962936bf md: fix clearing of the 'changed' flags for the bad blocks list.
In super_1_sync (the first hunk) we need to clear 'changed' before
checking read_seqretry(), otherwise we might race with other code
adding a bad block and so won't retry later.

In md_update_sb (the second hunk), in the case where there is no
metadata (neither persistent nor external), we treat any bad blocks as
an error.  However we need to clear the 'changed' flag before calling
md_ack_all_badblocks, else it won't do anything.

This patch is suitable for -stable release 3.0 and later.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown 57148964d9 md/bitmap: move printing of bitmap status to bitmap.c
The part of /proc/mdstat which describes the bitmap should really
be generated by code in bitmap.c.  So move it there.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown 050b66152f md/raid10: handle merge_bvec_fn in member devices.
Currently we don't honour merge_bvec_fn in member devices so if there
is one, we force all requests to be single-page at most.
This is not ideal.

So enhance the raid10 merge_bvec_fn to check that function in children
as well.

This introduces a small problem.  There is no locking around calls
the ->merge_bvec_fn and subsequent calls to ->make_request.  So a
device added between these could end up getting a request which
violates its merge_bvec_fn.

Currently the best we can do is synchronize_sched().  This will work
providing no preemption happens.  If there is preemption, we just
have to hope that new devices are largely consistent with old devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown dafb20fa34 md: tidy up rdev_for_each usage.
md.h has an 'rdev_for_each()' macro for iterating the rdevs in an
mddev.  However it uses the 'safe' version of list_for_each_entry,
and so requires the extra variable, but doesn't include 'safe' in the
name, which is useful documentation.

Consequently some places use this safe version without needing it, and
many use an explicity list_for_each entry.

So:
 - rename rdev_for_each to rdev_for_each_safe
 - create a new rdev_for_each which uses the plain
   list_for_each_entry,
 - use the 'safe' version only where needed, and convert all other
   list_for_each_entry calls to use rdev_for_each.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown c744a65c1e md: don't set md arrays to readonly on shutdown.
It seems that with recent kernel, writeback can still be happening
while shutdown is happening, and consequently data can be written
after the md reboot notifier switches all arrays to read-only.
This causes a BUG.

So don't switch them to read-only - just mark them clean and
set 'safemode' to '2' which mean that immediately after any
write the array will be switch back to 'clean'.

This could result in the shutdown happening when array is marked
dirty, thus forcing a resync on reboot.  However if you reboot
without performing a "sync" first, you get to keep both halves.

This is suitable for any stable kernel (though there might be some
conflicts with obvious fixes in earlier kernels).

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:37 +11:00
Linus Torvalds 4d39aa1b99 Some simple md-related fixes.
1/ two small fixes to ensure we handle an interrupted resync properly.
 2/ avoid loading the bitmap multiple times in dm-raid
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIVAwUATzMdiTnsnt1WYoG5AQKICw/9H3Xf/3crCCVRQ+yzSdZ1ZJH24Rps9O6W
 8dLFN4/Ng/qxymWUMrgHAMq5MEEz2M3i7W+j23lFv6Oce06y8GJ4PpoYY5xlXCgO
 SIU1BaO1JFHxQn89EQtP3iOn4AOiZvX0GUObR0P8KO1mMnLmN7cg8J1kBfmQiBKu
 aXcUqqNvcywoix6ve4O/xgnZjd4IExxqG3W8U7CaIwExUDwaLY4NckxJcIJbIYy9
 iapOGMUdcyr6xm819V/xE2DyAtfFCtvAk1hfW/dM4QQctran3MzQIRFn9RW+CwHU
 ComEnv5ti/7g//JPXQArUPk4xgRHrMhqFcmmD8rozJ6FJDi8vw2e0BXaRLVqa0mK
 1qSZkr0Ot3nwAdILzgSbNXQ0Y5OJgc9OLX5GGlVibTW2VTJYFgA7jAsnqq8PAJC5
 sU5h2K3jrSy2unGy6BxleL5D/wvREE5OBnW35TEB5TYbxjp1FLgn+BWp8FfFUYWT
 Eb2cIyAj6cBFJ3ma1K0RH0dmS9cbNjuG+CLiApJOnEEsXzrp/4KnqOwg4672ewW3
 m1Ue2Qv+0avaK3sVyT+qzuemc6b0ps/dix0gMXw2pYqXQWHquW5NdUJcgD2DKFSn
 BB734nUP6KlPg0IFh1eehRHyVRLIAot/uBlUJ3bMx9xeYCkKa+twX90u6EmjTopP
 JjLxNsf6c2I=
 =k0Xz
 -----END PGP SIGNATURE-----

Merge tag 'md-3.3-fixes' of git://neil.brown.name/md

Some simple md-related fixes.

1/ two small fixes to ensure we handle an interrupted resync properly.
2/ avoid loading the bitmap multiple times in dm-raid

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md: two small fixes to handling interrupt resync.
  Prevent DM RAID from loading bitmap twice.
2012-02-08 19:06:30 -08:00
NeilBrown db91ff55bd md: two small fixes to handling interrupt resync.
1/ If a resync is aborted we should record how far we got
 (recovery_cp) the last request that we know has completed
 (->curr_resync_completed) rather than the last request that was
 submitted (->curr_resync).

2/ When a resync aborts we still want to update the metadata with
 any changes, so set MD_CHANGE_DEVS even if we 'skip'.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-02-07 12:01:51 +11:00
Linus Torvalds b3c9dd182e Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
  Revert "block: recursive merge requests"
  block: Stop using macro stubs for the bio data integrity calls
  blockdev: convert some macros to static inlines
  fs: remove unneeded plug in mpage_readpages()
  block: Add BLKROTATIONAL ioctl
  block: Introduce blk_set_stacking_limits function
  block: remove WARN_ON_ONCE() in exit_io_context()
  block: an exiting task should be allowed to create io_context
  block: ioc_cgroup_changed() needs to be exported
  block: recursive merge requests
  block, cfq: fix empty queue crash caused by request merge
  block, cfq: move icq creation and rq->elv.icq association to block core
  block, cfq: restructure io_cq creation path for io_context interface cleanup
  block, cfq: move io_cq exit/release to blk-ioc.c
  block, cfq: move icq cache management to block core
  block, cfq: move io_cq lookup to blk-ioc.c
  block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
  block, cfq: reorganize cfq_io_context into generic and cfq specific parts
  block: remove elevator_queue->ops
  block: reorder elevator switch sequence
  ...

Fix up conflicts in:
 - block/blk-cgroup.c
	Switch from can_attach_task to can_attach
 - block/cfq-iosched.c
	conflict with now removed cic index changes (we now use q->id instead)
2012-01-15 12:24:45 -08:00
Linus Torvalds c086ae4ed9 Two bugfixes for md.
One is a recently introduced regression that affects an unusual
 configuration with a guaranteed BUG_ON.  Has been tagged for -stable.
 The other is minor missing functionality.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIVAwUATwy6Sznsnt1WYoG5AQL+5A//TbTgElZaJ7IMY4q658afuRNtuWfevqTs
 4EoSUvarwyZN20JxUd4dFTzLQ3nu3XVmwZsDBbpRs7+Dt2m7Efp4qytqrTxHb6SR
 4gOr1KFXZi2rQFNpIg8T5+eyb+2VkbHGYffOtwS9TZnJqZZ4upffJi1EpJSfB1Bo
 ilkO8wcaNKVWzTgnQo+JVOLQQyNENs12Xc0aLVA0dZC0a37qWJTbr75r7nrtLT7A
 Gy783AG8JglRsr7AOVceqBVOpRonhFDz7G2hQqHg140m6i/GzDJrPtadovCtq7nt
 U6/Po7qbOj5eOSGrVPwS1gJQOT7deAL7Eeu7dOpbzl1Cwysbhg63piMNyDs4P/gM
 bFsR+LTbmZiaYs5G1oDwN/WTYLeq6cxY0IftShWdGoQwZRF/woJ7VAQSWNvHY8mg
 Z+EbEL3sY40+8eBk7/umT0WxQ9wYjooS/9ZowQ2ktRmt82Dwv0LXzWNTSlwhWKKt
 QBtv1er/psEKFqb2zDtlea8gDlKahaVNaiOK6RuY5CM5iBa4/zEmWVXS/i07LC7Z
 cW9swD4J3AEKSolWHWYQJBmCsKy+rUp5t0mQ5e/O4+nhCDbfe+Da0OArg6b/ygMu
 14RdyjOENxSqKi3IkCnToch+eNzCIm3ETaS2E0nSv996G+ShqsLtROOI9x9DXiu3
 nyLxAnIVp8I=
 =969y
 -----END PGP SIGNATURE-----

Merge tag 'md-3.3-fixes' of git://neil.brown.name/md

Two bugfixes for md.

One is a recently introduced regression that affects an unusual
configuration with a guaranteed BUG_ON.  Has been tagged for -stable.
The other is minor missing functionality.

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md/raid1: perform bad-block tests for WriteMostly devices too.
  md: notify the 'degraded' sysfs attribute on failure.
2012-01-11 18:51:55 -08:00
Martin K. Petersen b1bd055d39 block: Introduce blk_set_stacking_limits function
Stacking driver queue limits are typically bounded exclusively by the
capabilities of the low level devices, not by the stacking driver
itself.

This patch introduces blk_set_stacking_limits() which has more liberal
metrics than the default queue limits function. This allows us to
inherit topology parameters from bottom devices without manually
tweaking the default limits in each driver prior to calling the stacking
function.

Since there is now a clear distinction between stacking and low-level
devices, blk_set_default_limits() has been modified to carry the more
conservative values that we used to manually set in
blk_queue_make_request().

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-01-11 16:27:11 +01:00
NeilBrown f2a371c5e7 md: notify the 'degraded' sysfs attribute on failure.
We currently only 'notify' changes to the 'degraded' attribute
when it decreases, not when it increases.

Notifying on failure is a little awkward as it happen in
interrupt context.
So instead, notify when we remove the failed device from the array,
which is very soon afterwards.

Reported-and-tested-by: Mikhail Balabin <mbalabin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-01-11 08:35:14 +11:00
Linus Torvalds 2943c83322 md update for 3.3
Big change is new hot-replacement.
 A slot in an array can hold 2 devices - one that
 wants-replacement and one that is the replacement.
 Once the replacement is built - either from the
 original or (in the case of errors) from elsewhere,
 the wants-replacement device will be removed.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIVAwUATwUdyDnsnt1WYoG5AQJBExAAuFQrzt7CN32nmiqaLlJ1snBC/ixOSJf7
 0X88YB+utO0qNIhiRTI1AulslRGms9pChyKmZZaxU2Hvzk1pTrFspsc8RlJTIv9S
 Si43due99Np08/Kf5rjYulyH0fcug0qIqlrCiBvc36pOIHZzam6IzrEvKFf0dqbe
 4vtLWuylEUiSEbN5gBordfTFZcxSPI/huMUgx6hEpdA4NtaPmN57/03d49k4RYgp
 f5l9htuIqdMgHwNJRUDGMooifuvILC5HXINUbsCFT6KUF/bxA75nW7W3C2BUq0V/
 CVb/ZoHFYtuaGBEcMUzN34k0DbHghPeSmlvXT4XWq7+gVNqGe33nbSJsx1oLXWr1
 m/b3j4Ublv+VVd7L1Rr40vTRB6wN5/2uN7SiD6d83ppPD0TuAY8YvMHgoLZQmQvh
 Ak4fEz07re+tueKhHwbi+1qMIw/ciQ9O/tI7r+AsVklkAxJNAfFKW6FOEFL2cjEW
 h4rbg1z9sU+xD8G01LBnJ0to/ajrJ4ch4wV/raLgi4+dJ4Tt3+/tas6WJlxHbyFF
 IiHCFM0+KcxLcwNkalZYg/zr5qu7EcwpPKLnc68m+LjXlYVWcnNHwv5WnOCHHQTw
 6yurGGlKqBfvsb8zJJGSRWqEtRSYjDlZiMt10/u+H40HiCiLX//vSvVbZoFiwWu1
 VzgEhzhvaYw=
 =j00/
 -----END PGP SIGNATURE-----

Merge tag 'md-3.3' of git://neil.brown.name/md

md update for 3.3

Big change is new hot-replacement.
A slot in an array can hold 2 devices - one that
wants-replacement and one that is the replacement.
Once the replacement is built - either from the
original or (in the case of errors) from elsewhere,
the wants-replacement device will be removed.

* tag 'md-3.3' of git://neil.brown.name/md: (36 commits)
  md/raid1: Mark device want_replacement when we see a write error.
  md/raid1: If there is a spare and a want_replacement device, start replacement.
  md/raid1: recognise replacements when assembling arrays.
  md/raid1: handle activation of replacement device when recovery completes.
  md/raid1: Allow a failed replacement device to be removed.
  md/raid1: Allocate spare to store replacement devices and their bios.
  md/raid1:  Replace use of mddev->raid_disks with conf->raid_disks.
  md/raid10: If there is a spare and a want_replacement device, start replacement.
  md/raid10: recognise replacements when assembling array.
  md/raid10: Allow replacement device to be replace old drive.
  md/raid10: handle recovery of replacement devices.
  md/raid10:  Handle replacement devices during resync.
  md/raid10: writes should get directed to replacement as well as original.
  md/raid10: allow removal of failed replacement devices.
  md/raid10: preferentially read from replacement device if possible.
  md/raid10:  change read_balance to return an rdev
  md/raid10: prepare data structures for handling replacement.
  md/raid5: Mark device want_replacement when we see a write error.
  md/raid5: If there is a spare and a want_replacement device, start replacement.
  md/raid5: recognise replacements when assembling array.
  ...
2012-01-08 13:28:33 -08:00
Al Viro ff01bb4832 fs: move code out of buffer.c
Move invalidate_bdev, block_sync_page into fs/block_dev.c.  Export
kill_bdev as well, so brd doesn't have to open code it.  Reduce
buffer_head.h requirement accordingly.

Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving.  The small comment replacing it says enough.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:07 -05:00
NeilBrown 7bfec5f35c md/raid5: If there is a spare and a want_replacement device, start replacement.
When attempting to add a spare to a RAID[456] array, also consider
adding it as a replacement for a want_replacement device.

This requires that common md code attempt hot_add even when the array
is not formally degraded.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown 2d78f8c451 md: create externally visible flags for supporting hot-replace.
hot-replace is a feature being added to md which will allow a
device to be replaced without removing it from the array first.

With hot-replace a spare can be activated and recovery can start while
the original device is still in place, thus allowing a transition from
an unreliable device to a reliable device without leaving the array
degraded during the transition.  It can also be use when the original
device is still reliable but it not wanted for some reason.

This will eventually be supported in RAID4/5/6 and RAID10.

This patch adds a super-block flag to distinguish the replacement
device.  If an old kernel sees this flag it will reject the device.

It also adds two per-device flags which are viewable and settable via
sysfs.
   "want_replacement" can be set to request that a device be replaced.
   "replacement" is set to show that this device is replacing another
   device.

The "rd%d" links in /sys/block/mdXx/md only apply to the original
device, not the replacement.  We currently don't make links for the
replacement - there doesn't seem to be a need.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown b8321b68d1 md: change hot_remove_disk to take an rdev rather than a number.
Soon an array will be able to have multiple devices with the
same raid_disk number (an original and a replacement).  So removing
a device based on the number won't work.  So pass the actual device
handle instead.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown 476a7abb9b md: remove test for duplicate device when setting slot number.
When setting the slot number on a device in an active array we
currently check that the number is not already in use.
We then call into the personality's hot_add_disk function
which performs the same test and returns the same error.

Thus the common test is not needed.

As we will shortly be changing some personalities to allow duplicates
in some cases (to support hot-replace), the common test will become
inconvenient.

So remove the common test.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown 506c9e44a8 md: allow non-privileged uses to GET_*_INFO about raid arrays.
The info is already available in /proc/mdstat and /sys/block in
an accessible form so there is no point in putting a road-block in
the ioctl for information gathering.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:26 +11:00
NeilBrown 60fc13702a md: don't give up looking for spares on first failure-to-add
Before performing a recovery we try to remove any spares that
might not be working, then add any that might have become relevant.

Currently we abort on the first spare that cannot be added.
This is a false optimisation.
It is conceivable that - depending on rules in the personality - a
subsequent spare might be accepted.
Also the loop does other things like count the available spares and
reset the 'recovery_offset' value.

If we abort early these might not happen properly.

So remove the early abort.

In particular if you have an array what is undergoing recovery and
which has extra spares, then the recovery may not restart after as
reboot as the could of 'spares' might end up as zero.

Reported-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:57:19 +11:00
NeilBrown 8bd2f0a05b md: ensure new badblocks are handled promptly.
When we mark blocks as bad we need them to be acknowledged by the
metadata handler promptly.

For an in-kernel metadata handler that was already being done.  But
for an external metadata handler we need to alert it of the change by
sending a notification through the sysfs file.  This adds that
notification.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 16:26:08 +11:00
NeilBrown 52c64152a9 md: bad blocks shouldn't cause a Blocked status on a Faulty device.
Once a device is marked Faulty the badblocks - whether acknowledged or
not - become irrelevant.  So they shouldn't cause the device to be
marked as Blocked.

Without this patch, a process might write "-blocked" to clear the
Blocked status, but while that will correctly fail the device, it
won't remove the apparent 'blocked' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 16:22:48 +11:00
NeilBrown af8a24347f md: take a reference to mddev during sysfs access.
When we are accessing an mddev via sysfs we know that the
mddev cannot disappear because it has an embedded kobj which
is refcounted by sysfs.
And we also take the mddev_lock.
However this is not enough.

The final mddev_put could have been called and the
mddev_delayed_delete is waiting for sysfs to let go so it can destroy
the kobj and mddev.
In this state there are a lot of changes that should not be attempted.

To to guard against this we:
 - initialise mddev->all_mddevs in on last put so the state can be
   easily detected.
 - in md_attr_show and md_attr_store, check ->all_mddevs under
   all_mddevs_lock and mddev_get the mddev if it still appears to
   be active.

This means that if we get to sysfs as the mddev is being deleted we
will get -EBUSY.

rdev_attr_store and rdev_attr_show are similar but already have
sufficient protection.  They check that rdev->mddev still points to
mddev after taking mddev_lock.  As this is cleared  before delayed
removal which can only be requested under the mddev_lock, this
ensure the rdev and mddev are still alive.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 15:49:46 +11:00
NeilBrown 1d23f178d5 md: refine interpretation of "hold_active == UNTIL_IOCTL".
We like md devices to disappear when they really are not needed.
However it is not possible to tell from the current state whether it
is needed or not.  We can only tell from recent history of changes.

In particular immediately after we create an md device it looks very
similar to immediately after we have finished with it.

So we always preserve a newly created md device until something
significant happens.  This state is stored in 'hold_active'.

The normal case is to keep it until an ioctl happens, as that will
normally either activate it, or explicitly de-activate it.  If it
doesn't then it was probably created by mistake and it is now time to
get rid of it.

We can also modify an array via sysfs (instead of via ioctl) and we
currently treat any change via sysfs like an ioctl as a sign that if
it now isn't more active, it should be destroyed.
However this is not appropriate as changes made via sysfs are more
gradual so we should look for a more definitive change.

So this patch only clears 'hold_active' from UNTIL_IOCTL to clear when
the array_state is changed via sysfs.  Other changes via sysfs
are ignored.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 15:49:12 +11:00
Linus Torvalds 32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Linus Torvalds b4fdcb02f1 Merge branch 'for-3.2/core' of git://git.kernel.dk/linux-block
* 'for-3.2/core' of git://git.kernel.dk/linux-block: (29 commits)
  block: don't call blk_drain_queue() if elevator is not up
  blk-throttle: use queue_is_locked() instead of lockdep_is_held()
  blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
  blk-throttle: Free up policy node associated with deleted rule
  block: warn if tag is greater than real_max_depth.
  block: make gendisk hold a reference to its queue
  blk-flush: move the queue kick into
  blk-flush: fix invalid BUG_ON in blk_insert_flush
  block: Remove the control of complete cpu from bio.
  block: fix a typo in the blk-cgroup.h file
  block: initialize the bounce pool if high memory may be added later
  block: fix request_queue lifetime handling by making blk_queue_cleanup() properly shutdown
  block: drop @tsk from attempt_plug_merge() and explain sync rules
  block: make get_request[_wait]() fail if queue is dead
  block: reorganize throtl_get_tg() and blk_throtl_bio()
  block: reorganize queue draining
  block: drop unnecessary blk_get/put_queue() in scsi_cmd_ioctl() and blk_get_tg()
  block: pass around REQ_* flags instead of broken down booleans during request alloc/free
  block: move blk_throtl prototypes to block/blk.h
  block: fix genhd refcounting in blkio_policy_parse_and_set()
  ...

Fix up trivial conflicts due to "mddev_t" -> "struct mddev" conversion
and making the request functions be of type "void" instead of "int" in
 - drivers/md/{faulty.c,linear.c,md.c,md.h,multipath.c,raid0.c,raid1.c,raid10.c,raid5.c}
 - drivers/staging/zram/zram_drv.c
2011-11-04 17:06:58 -07:00
Paul Gortmaker 056075c764 md: Add module.h to all files using it implicitly
A pending cleanup will mean that module.h won't be implicitly
everywhere anymore.  Make sure the modular drivers in md dir
are actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:18 -04:00
Jens Axboe 5c04b426f2 Merge branch 'v3.1-rc10' into for-3.2/core
Conflicts:
	block/blk-core.c
	include/linux/blkdev.h

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-19 14:30:42 +02:00
Chris Dunlop 751e67ca2e md.c: trivial comment fix
Trivial comment fix

Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-19 17:15:15 +11:00
Andrei Warkentin d70ed2e4fa MD: Allow restarting an interrupted incremental recovery.
If an incremental recovery was interrupted, a subsequent
re-add will result in a full recovery, even though an
incremental should be possible (seen with raid1).

Solve this problem by not updating the superblock on the
recovering device until array is not degraded any longer.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:16:48 +11:00
NeilBrown d30519fc59 md: clear In_sync bit on devices added to an active array.
When we add a device to an active array it can be meaningful to set
the 'insync' flag.  This indicates that the device is in-sync with the
array except for locations recorded in the bitmap.
A bitmap-based recovery can then bring it completely in-sync.

Internally we move that flag to 'saved_raid_disk' but forgot to clear
In_sync like we do in add_new_disk.

So clear In_sync after moving its value to saved_raid_disk.

Reported-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:13:47 +11:00
NeilBrown 84fc4b56db md: rename "mdk_personality" to "md_personality"
"mdk" doesn't mean anything any more.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:58 +11:00
NeilBrown 2b8bf3451d md: remove typedefs: mdk_thread_t -> struct md_thread
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:23 +11:00
NeilBrown fd01b88c75 md: remove typedefs: mddev_t -> struct mddev
Having mddev_t and 'struct mddev_s' is ugly and not preferred

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:47:53 +11:00
NeilBrown 3cb0300200 md: removing typedefs: mdk_rdev_t -> struct md_rdev
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:45:26 +11:00
NeilBrown 36a4e1fe0f md: remove PRINTK and dprintk debugging and use pr_debug
Being able to dynamically enable these make them much more useful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:17 +11:00
Daniel P. Berrange 2dba6a911c md: don't delay reboot by 1 second if no MD devices exist
The md_notify_reboot() method includes a call to mdelay(1000),
to deal with "exotic SCSI devices" which are too volatile on
reboot. The delay is unconditional. Even if the machine does
not have any block devices, let alone MD devices, the kernel
shutdown sequence is slowed down.

1 second does not matter much with physical hardware, but with
certain virtualization use cases any wasted time in the bootup
& shutdown sequence counts for alot.

* drivers/md/md.c: md_notify_reboot() - only impose a delay if
  there was at least one MD device to be stopped during reboot

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-23 19:54:04 +10:00
NeilBrown 01f96c0a99 md: Avoid waking up a thread after it has been freed.
Two related problems:

1/ some error paths call "md_unregister_thread(mddev->thread)"
   without subsequently clearing ->thread.  A subsequent call
   to mddev_unlock will try to wake the thread, and crash.

2/ Most calls to md_wakeup_thread are protected against the thread
   disappeared either by:
      - holding the ->mutex
      - having an active request, so something else must be keeping
        the array active.
   However mddev_unlock calls md_wakeup_thread after dropping the
   mutex and without any certainty of an active request, so the
   ->thread could theoretically disappear.
   So we need a spinlock to provide some protections.

So change md_unregister_thread to take a pointer to the thread
pointer, and ensure that it always does the required locking, and
clears the pointer properly.

Reported-by: "Moshe Melnikov" <moshe@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
cc: stable@kernel.org
2011-09-21 15:30:20 +10:00
Christoph Hellwig 5a7bbad27a block: remove support for bio remapping from ->make_request
There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.

Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-09-12 12:12:01 +02:00
NeilBrown 27a7b260f7 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.
0.90 metadata uses an unsigned 32bit number to count the number of
kilobytes used from each device.
This should allow up to 4TB per device.
However we multiply this by 2 (to get sectors) before casting to a
larger type, so sizes above 2TB get truncated.

Also we allow rdev->sectors to be larger than 4TB, so it is possible
for the array to be resized larger than the metadata can handle.
So make sure rdev->sectors never exceeds 4TB when 0.90 metadata is in
used.

Also the sanity check at the end of super_90_load should include level
1 as it used ->size too. (RAID0 and Linear don't use ->size at all).

Reported-by: Pim Zandbergen <P.Zandbergen@macroscoop.nl>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:28 +10:00
NeilBrown 7da64a0abc md: fix clearing of 'blocked' flag in the presence of bad blocks.
When the 'blocked' flag on a device is cleared while there are
unacknowledged bad blocks we must fail the device.  This is needed for
backwards compatability of the interface.

The code currently uses the wrong test for "unacknowledged bad blocks
exist".  Change it to the right test.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-30 16:20:17 +10:00
Namhyung Kim a5bf4df0c8 md: use REQ_NOIDLE flag in md_super_write()
Queue idling is used for the anticipation of immediate
sequencial I/O's but md_super_write() is a kind of one-
shot operation, coupled with md_super_wait(), so the
idling in this case will be just a waste of time.

Specifying REQ_NOIDLE prevents it. Instead of adding
the flag to submit_bio() directly, use pre-defined
macro WRITE_FLUSH_FUA.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:34 +10:00
NeilBrown aeb9b21184 md: ensure changes to 'write-mostly' are reflected in metadata.
The 'write-mostly' flag can be changed through sysfs.
With 0.90 metadata, those changes are reflected in the metadata.
For 1.x metadata, they aren't.

So fix super_1_sync to record 'write-mostly' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:08 +10:00
NeilBrown 5ef56c8fec md: report failure if a 'set faulty' request doesn't.
Sometimes a device will refuse to be set faulty.  e.g. RAID1 will
never let the last working device become faulty.

So check if "md_error()" did manage to set the faulty flag and fail
with EBUSY if it didn't.

Resolves-Debian-Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601198
Reported-by: Mike Hommey <mh+reportbug@glandium.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:42:51 +10:00
Linus Torvalds 6140333d36 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (75 commits)
  md/raid10: handle further errors during fix_read_error better.
  md/raid10: Handle read errors during recovery better.
  md/raid10: simplify read error handling during recovery.
  md/raid10: record bad blocks due to write errors during resync/recovery.
  md/raid10:  attempt to fix read errors during resync/check
  md/raid10:  Handle write errors by updating badblock log.
  md/raid10: clear bad-block record when write succeeds.
  md/raid10: avoid writing to known bad blocks on known bad drives.
  md/raid10 record bad blocks as needed during recovery.
  md/raid10: avoid reading known bad blocks during resync/recovery.
  md/raid10 - avoid reading from known bad blocks - part 3
  md/raid10: avoid reading from known bad blocks - part 2
  md/raid10: avoid reading from known bad blocks - part 1
  md/raid10: Split handle_read_error out from raid10d.
  md/raid10: simplify/reindent some loops.
  md/raid5: Clear bad blocks on successful write.
  md/raid5.  Don't write to known bad block on doubtful devices.
  md/raid5: write errors should be recorded as bad blocks if possible.
  md/raid5: use bad-block log to improve handling of uncorrectable read errors.
  md/raid5: avoid reading from known bad blocks.
  ...
2011-07-28 05:50:27 -07:00
NeilBrown e875ecea26 md/raid10 record bad blocks as needed during recovery.
When recovering one or more devices, if all the good devices have
bad blocks we should record a bad block on the device being rebuilt.

If this fails, we need to abort the recovery.

To ensure we don't think that we aborted later than we actually did,
we need to move the check for MD_RECOVERY_INTR earlier in md_do_sync,
in particular before mddev->curr_resync is updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown de393cdea6 md: make it easier to wait for bad blocks to be acknowledged.
It is only safe to choose not to write to a bad block if that bad
block is safely recorded in metadata - i.e. if it has been
'acknowledged'.

If it hasn't we need to wait for the acknowledgement.

We support that using rdev->blocked wait and
md_wait_for_blocked_rdev by introducing a new device flag
'BlockedBadBlock'.

This flag is only advisory.
It is cleared whenever we acknowledge a bad block, so that a waiter
can re-check the particular bad blocks that it is interested it.

It should be set by a caller when they find they need to wait.
This (set after test) is inherently racy, but as
md_wait_for_blocked_rdev already has a timeout, losing the race will
have minimal impact.

When we clear "Blocked" was also clear "BlockedBadBlocks" incase it
was set incorrectly (see above race).

We also modify the way we manage 'Blocked' to fit better with the new
handling of 'BlockedBadBlocks' and to make it consistent between
externally managed and internally managed metadata.   This requires
that each raidXd loop checks if the metadata needs to be written and
triggers a write (md_check_recovery) if needed.  Otherwise a queued
write request might cause raidXd to wait for the metadata to write,
and only that thread can write it.

Before writing metadata, we set FaultRecorded for all devices that
are Faulty, then after writing the metadata we clear Blocked for any
device for which the Fault was certainly Recorded.

The 'faulty' device flag now appears in sysfs if the device is faulty
*or* it has unacknowledged bad blocks.  So user-space which does not
understand bad blocks can continue to function correctly.
User space which does, should not assume a device is faulty until it
sees the 'faulty' flag, and then sees the list of unacknowledged bad
blocks is empty.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown d7a9d443bc md: add 'write_error' flag to component devices.
If a device has ever seen a write error, we will want to handle
known-bad-blocks differently.
So create an appropriate state flag and export it via sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:48 +10:00
NeilBrown d2eb35acfd md/raid1: avoid reading from known bad blocks.
Now that we have a bad block list, we should not read from those
blocks.
There are several main parts to this:
  1/ read_balance needs to check for bad blocks, and return not only
     the chosen device, but also how many good blocks are available
     there.
  2/ fix_read_error needs to avoid trying to read from bad blocks.
  3/ read submission must be ready to issue multiple reads to
     different devices as different bad blocks on different devices
     could mean that a single large read cannot be served by any one
     device, but can still be served by the array.
     This requires keeping count of the number of outstanding requests
     per bio.  This count is stored in 'bi_phys_segments'
  4/ retrying a read needs to also be ready to submit a smaller read
     and queue another request for the rest.

This does not yet handle bad blocks when reading to perform resync,
recovery, or check.

'md_trim_bio' will also be used for RAID10, so put it in md.c and
export it.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown 9f2f383078 md: Disable bad blocks and v0.90 metadata.
v0.90 metadata cannot record bad blocks, so when loading metadata
for such a device, set shift to -1.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown 2699b67223 md: load/store badblock list from v1.x metadata
Space must have been allocated when array was created.
A feature flag is set when the badblock list is non-empty, to
ensure old kernels don't load and trust the whole device.

We only update the on-disk badblocklist when it has changed.
If the badblocklist (or other metadata) is stored on a bad block, we
don't cope very well.

If metadata has no room for bad block, flag bad-blocks as disabled,
and do the same for 0.90 metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown 16c791a5af md/bad-block-log: add sysfs interface for accessing bad-block-log.
This can show the log (providing it fits in one page) and
allows bad blocks to be 'acknowledged' meaning that they
have safely been recorded in metadata.

Clearing bad blocks is not allowed via sysfs (except for
code testing).  A bad block can only be cleared when
a write to the block succeeds.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:47 +10:00
NeilBrown 2230dfe4cc md: beginnings of bad block management.
This the first step in allowing md to track bad-blocks per-device so
that we can fail individual blocks rather than the whole device.

This patch just adds a data structure for recording bad blocks, with
routines to add, remove, search the list.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:46 +10:00
NeilBrown a519b26dbe md: remove suspicious size_of()
When calling bioset_create we pass the size of the front_pad as
   sizeof(mddev)
which looks suspicious as mddev is a pointer and so it looks like a
common mistake where
   sizeof(*mddev)
was intended.
The size is actually correct as we want to store a pointer in the
front padding of the bios created by the bioset, so make the intent
more explicit by using
   sizeof(mddev_t *)

Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 07:56:24 +10:00
Jonathan Brassow 768e587e18 MD: generate an event when array sync is complete
This patch causes MD to generate an event (for device-mapper) when the
synchronization thread is reaped.  This is expected behavior for device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:37 +10:00
Namhyung Kim 65a06f0674 md: get rid of unnecessary casts on page_address()
page_address() returns void pointer, so the casts can be removed.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown 5389042ffa md: change managed of recovery_disabled.
If we hit a read error while recovering a mirror, we want to abort the
recovery without necessarily failing the disk - as having a disk this
a read error is better than not having an array at all.

Currently this is managed with a per-array flag "recovery_disabled"
and is only implemented for RAID1.  For RAID10 we will need finer
grained control as we might want to disable recovery for individual
devices separately.

So push more of the decision making into the personality.
'recovery_disabled' is now a 'cookie' which is copied when the
personality want to disable recovery and is changed when a device is
added to the array as this is used as a trigger to 'try recovery
again'.

This will allow RAID10 to get the control that it needs.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim a478a069b6 md: remove ro check in md_check_recovery()
Commit c89a8eee61 ("Allow faulty devices to be removed from a
readonly array.") added some work on ro array in the function,
but it couldn't be done since we didn't allow the ro array to be
handled from the beginning. Fix it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim 36fad858a7 md: introduce link/unlink_rdev() helpers
There are places where sysfs links to rdev are handled
in a same way. Add the helper functions to consolidate
them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Kay Sievers f15146380d fs: seq_file - add event counter to simplify poll() support
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
NeilBrown 4274215d24 md: avoid endless recovery loop when waiting for fail device to complete.
If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Cc: stable@kernel.org
Reported-by: Jim Paradis <james.paradis@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-28 16:59:42 +10:00
Namhyung Kim 01393f3d58 md: check ->hot_remove_disk when removing disk
Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store()
during disk removal. The linear personality only has ->hot_add_disk and
no ->hot_remove_disk, so that removing disk in the array resulted to
following kernel bug:

$ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3]
$ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<          (null)>]           (null)
 PGD c9f5d067 PUD 8575a067 PMD 0
 Oops: 0010 [#1] SMP
 CPU 2
 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg

 Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
 RSP: 0018:ffff880085757df0  EFLAGS: 00010282
 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e
 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000
 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a
 R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff
 R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000
 FS:  00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000)
 Stack:
  ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000
  ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90
  ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98
 Call Trace:
  [<ffffffff8138496a>] ? slot_store+0xaa/0x265
  [<ffffffff81384bae>] rdev_attr_store+0x89/0xa8
  [<ffffffff8115a96a>] sysfs_write_file+0x108/0x144
  [<ffffffff81106b87>] vfs_write+0xb1/0x10d
  [<ffffffff8106e6c0>] ? trace_hardirqs_on_caller+0x111/0x135
  [<ffffffff81106cac>] sys_write+0x4d/0x77
  [<ffffffff814fe702>] system_call_fastpath+0x16/0x1b
 Code:  Bad RIP value.
 RIP  [<          (null)>]           (null)
  RSP <ffff880085757df0>
 CR2: 0000000000000000
 ---[ end trace ba5fc64319a826fb ]---

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:54 +10:00
马建朋 9864c0053d md: Using poll /proc/mdstat can monitor the events of adding a spare disks
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:48 +10:00
Jonathan Brassow 076f968b37 MD: add sync_super to mddev_t struct
Add the 'sync_super' function pointer to MD array structure (struct mddev_s)

If device-mapper (dm-raid.c) is to define its own on-disk superblock and be
able to load it, there must still be a way for MD to initiate superblock
updates.  The simplest way to make this happen is to provide a pointer in
the MD array structure that can be set by device-mapper (or other module)
with a function to do this.  If the function has been set, it will be used;
otherwise, the method with be looked up via 'super_types' as usual.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow 0fd018af37 MD: move thread wakeups into resume
Move personality and sync/recovery thread starting outside md_run.

Moving the wakeup's of the personality and sync/recovery threads out of
md_run and into do_md_run and mddev_resume solves two issues:
1) It allows bitmap_load to be called before the sync_thread is run and
2) when MD personalities are used by device-mapper (dm-raid.c), the start-up
of the array is better alligned with device-mapper primatives
(CTR/resume/suspend/DTR).  I/O - in this case, recovery operations - should
not happen until after a resume has taken place.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow ac42450c7c MD: possible typo
Make message a bit clearer by s/blocks/k/

I chose 'k' vs 'kiB' or 'kB' because it is what is used earlier in the
message.  'k' may be a bit ambigous, but I think it's better than "blocks"
which normally means 512, but means 1024 in MD.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow 68866e425b MD: no sync IO while suspended
Disallow resync I/O while the RAID array is suspended.

Recovery, resync, and metadata I/O should not be allowed while a device is
suspended.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
Jonathan Brassow 629acb6aba MD: no integrity register if no gendisk
Don't attempt md_integrity_register if there is no gendisk struct available.

When MD arrays are built via device-mapper, the gendisk structure is not
available via mddev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
NeilBrown b098636cf0 md: allow resync_start to be set while an array is active.
The sysfs attribute 'resync_start' (known internally as recovery_cp),
records where a resync is up to.  A value of 0 means the array is
not known to be in-sync at all.  A value of MaxSector means the array
is believed to be fully in-sync.

When the size of member devices of an array (RAID1,RAID4/5/6) is
increased, the array can be increased to match.  This process sets
resync_start to the old end-of-device offset so that the new part of
the array gets resynced.

However with RAID1 (and RAID6) a resync is not technically necessary
and may be undesirable.  So it would be good if the implied resync
after the array is resized could be avoided.

So: change 'resync_start' so the value can be changed while the array
is active, and as a precaution only allow it to be changed while
resync/recovery is 'frozen'.  Changing it once resync has started is
not going to be useful anyway.

This allows the array to be resized without a resync by:
  write 'frozen' to 'sync_action'
  write new size to 'component_size' (this will set resync_start)
  write 'none' to 'resync_start'
  write 'idle' to 'sync_action'.

Also slightly improve some tests on recovery_cp when resizing
raid1/raid5.  Now that an arbitrary value could be set we should be
more careful in our tests.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 15:52:21 +10:00
NeilBrown bedd86b777 md: reject a re-add request that cannot be honoured.
The 'add_new_disk' ioctl can be used to add a device either as a
spare, or as an active disk that just needs to be resynced based on
write-intent-bitmap information (re-add)

Currently if a re-add is requested but fails we add as a spare
instead.  This makes it impossible for user-space to check for
failure.

So change to require that a re-add attempt will either succeed or
completely fail.  User-space can then decide what to do next.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:26:20 +10:00
NeilBrown b0140891a8 md: Fix race when creating a new md device.
There is a race when creating an md device by opening /dev/mdXX.

If two processes do this at much the same time they will follow the
call path
  __blkdev_get -> get_gendisk -> kobj_lookup

The first will call
  -> md_probe -> md_alloc -> add_disk -> blk_register_region

and the race happens when the second gets to kobj_lookup after
add_disk has called blk_register_region but before it returns to
md_alloc.

In the case the second will not call md_probe (as the probe is already
done) but will get a handle on the gendisk, return to __blkdev_get
which will then call md_open (via the ->open) pointer.

As mddev->gendisk hasn't been set yet, md_open will think something is
wrong an return with ERESTARTSYS.

This can loop endlessly while the first thread makes no progress
through add_disk.  Nothing is blocking it, but due to scheduler
behaviour it doesn't get a turn.
So this is essentially a live-lock.

We fix this by simply moving the assignment to mddev->gendisk before
the call the add_disk() so md_open doesn't get confused.
Also move blk_queue_flush earlier because add_disk should be as late
as possible.

To make sure that md_open doesn't complete until md_alloc has done all
that is needed, we take mddev->open_mutex during the last part of
md_alloc.  md_open will wait for this.

This can cause a lock-up on boot so Cc:ing for stable.
For 2.6.36 and earlier a different patch will be needed as the
'blk_queue_flush' call isn't there.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Tested-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Cc: stable@kernel.org
2011-05-11 14:26:17 +10:00
Krzysztof Wojcik fee68723cf md: Cleanup after raid45->raid0 takeover
Problem:
After raid4->raid0 takeover operation, another takeover operation
(e.g raid0->raid10) results "kernel oops".
Root cause:
Variables 'degraded' in mddev structure is not cleared
on raid45->raid0 takeover.

This patch reset this variable.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20 15:39:53 +10:00
NeilBrown 97658cdd3a md: provide generic support for handling unplug callbacks.
When an md device adds a request to a queue, it can call
mddev_check_plugged.
If this succeeds then we know that the md thread will be woken up
shortly, and ->plug_cnt will be non-zero until then, so some
processing can be delayed.

If it fails, then no unplug callback is expected and the make_request
function needs to do whatever is required to make the request happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
NeilBrown 482c083492 md - remove old plugging code.
md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.

This relied on the ->unplug_fn callback which doesn't exist any more.

So remove all of that code, both in md and raid5.  Subsequent patches
with restore the plugging functionality.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Martin K. Petersen 89078d572e md: Fix integrity registration error when no devices are capable
We incorrectly returned -EINVAL when none of the devices in the array
had an integrity profile.  This in turn prevented mdadm from starting
the metadevice.  Fix this so we only return errors on mismatched
profiles and memory allocation failures.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-28 17:53:29 -07:00
Linus Torvalds 6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Martin K. Petersen a91a2785b2 block: Require subsystems to explicitly allocate bio_set integrity mempool
MD and DM create a new bio_set for every metadevice. Each bio_set has an
integrity mempool attached regardless of whether the metadevice is
capable of passing integrity metadata. This is a waste of memory.

Instead we defer the allocation decision to MD and DM since we know at
metadevice creation time whether integrity passthrough is needed or not.

Automatic integrity mempool allocation can then be removed from
bioset_create() and we make an explicit integrity allocation for the
fs_bio_set.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Acked-by: Mike Snitzer <snizer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-17 11:11:05 +01:00
Linus Torvalds bd2895eead Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
2011-03-16 08:20:19 -07:00
Jens Axboe 4c63f5646e Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core
Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:58:35 +01:00
Jens Axboe 721a9602e6 block: kill off REQ_UNPLUG
With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:27 +01:00
Jens Axboe 7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
NeilBrown f0b4f7e2f2 md: Fix - again - partition detection when array becomes active
Revert
    b821eaa572
and
    f3b99be19d

When I wrote the first of these I had a wrong idea about the
lifetime of 'struct block_device'.  It can disappear at any time that
the block device is not open if it falls out of the inode cache.

So relying on the 'size' recorded with it to detect when the
device size has changed and so we need to revalidate, is wrong.

Rather, we really do need the 'changed' attribute stored directly in
the mddev and set/tested as appropriate.

Without this patch, a sequence of:
   mknod / open / close / unlink

(which can cause a block_device to be created and then destroyed)
will result in a rescan of the partition table and consequence removal
and addition of partitions.
Several of these in a row can get udev racing to create and unlink and
other code can get confused.

With the patch, the rescan is only performed when needed and so there
are no races.

This is suitable for any stable kernel from 2.6.35.

Reported-by: "Wojcik, Krzysztof" <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2011-02-24 17:26:41 +11:00
Tejun Heo 43d133c18b Merge branch 'master' into for-2.6.39 2011-02-21 09:43:56 +01:00
NeilBrown 8f5f02c460 md: correctly handle probe of an 'mdp' device.
'mdp' devices are md devices with preallocated device numbers
for partitions. As such it is possible to mknod and open a partition
before opening the whole device.

this causes  md_probe() to be called with a device number of a
partition, which in-turn calls mddev_find with such a number.

However mddev_find expects the number of a 'whole device' and
does the wrong thing with partition numbers.

So add code to mddev_find to remove the 'partition' part of
a device number and just work with the 'whole device'.

This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=28652

Reported-by: hkmaly@bigfoot.com
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: <stable@kernel.org>
2011-02-16 13:58:51 +11:00
NeilBrown cbe6ef1d26 md: don't set_capacity before array is active.
If the desired size of an array is set (via sysfs) before the array is
active (which is the normal sequence), we currrently call set_capacity
immediately.
This means that a subsequent 'open' (as can be caused by some
udev-triggers program) will notice the new size and try to probe for
partitions.  However as the array isn't quite ready yet the read will
fail.  Then when the array is read, as the size doesn't change again
we don't try to re-probe.

So when setting array size via sysfs, only call set_capacity if the
array is already active.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-16 13:58:38 +11:00
Chris Mason e91ece5590 md_make_request: don't touch the bio after calling make_request
md_make_request was calling bio_sectors() for part_stat_add
after it was calling the make_request function.  This is
bad because the make_request function can free the bio and
because the bi_size field can change around.

The fix here was suggested by Jens Axboe.  It saves the
sector count before the make_request call.  I hit this
with CONFIG_DEBUG_PAGEALLOC turned on while trying to break
his pretty fusionio card.

Cc: <stable@kernel.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-08 09:53:28 +11:00
NeilBrown c6751b2bde md: Don't allow slot_store while resync/recovery is happening.
Activating a spare in an array while resync/recovery is already
happening can lead the that spare being marked in-sync when it isn't
really.
So don't allow the 'slot' to be set (this activating the device)
while resync/recovery is happening.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-02 11:57:13 +11:00
NeilBrown 7281f8129c md: don't clear curr_resync_completed at end of resync.
There is no need to set this to zero at this point.  It will be
set to zero by remove_and_add_spares or at the start of
md_do_sync at the latest.
And setting it to zero before MD_RECOVERY_RUNNING is cleared can
make a 'zero' appear briefly in the 'sync_completed' sysfs attribute
just as resync is finishing.

So simply remove this setting to zero.


Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 14:30:27 +11:00
NeilBrown a8c42c7f47 md: Don't use remove_and_add_spares to remove failed devices from a read-only array
remove_and_add_spares is called in two places where the needs really
are very different.
remove_and_add_spares should not be called on an array which is about
to be reshaped as some extra devices might have been manually added
and that would remove them.  However if the array is 'read-auto',
that will currently happen, which is bad.

So in the 'ro != 0' case don't call remove_and_add_spares but simply
remove the failed devices as the comment suggests is needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 13:47:13 +11:00
NeilBrown f21e9ff7f7 md: Remove the AllReserved flag for component devices.
This flag is not needed and is used badly.

Devices that are included in a native-metadata array are reserved
exclusively for that array - and currently have AllReserved set.
They all are bd_claimed for the rdev and so cannot be shared.

Devices that are included in external-metadata arrays can be shared
among multiple arrays - providing there is no overlap.
These are bd_claimed for md in general - not for a particular rdev.

When changing the amount of a device that is used in an array we need
to check for overlap.  This currently includes a check on AllReserved
So even without overlap, sharing with an AllReserved device is not
allowed.
However the bd_claim usage already precludes sharing with these
devices, so the test on AllReserved is not needed.  And in fact it is
wrong.

As this is the only use of AllReserved, simply remove all usage and
definition of AllReserved.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 12:10:09 +11:00
NeilBrown de171cb9a5 md: revert change to raid_disks on failure.
If we try to update_raid_disks and it fails, we should put
'delta_disks' back to zero.  This is important because some code,
such as slot_store, assumes that delta_disks has been validated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:42 +11:00
Tejun Heo ada609ee2a workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
WQ_RESCUER is now an internal flag and should only be used in the
workqueue implementation proper.  Use WQ_MEM_RECLAIM instead.

This doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
2011-01-25 14:35:54 +01:00
Tejun Heo 49731baa41 block: restore multiple bd_link_disk_holder() support
Commit e09b457b (block: simplify holder symlink handling) incorrectly
assumed that there is only one link at maximum.  dm may use multiple
links and expects block layer to track reference count for each link,
which is different from and unrelated to the exclusive device holder
identified by @holder when the device is opened.

Remove the single holder assumption and automatic removal of the link
and revive the per-link reference count tracking.  The code
essentially behaves the same as before commit e09b457b sans the
unnecessary kobject reference count dancing.

While at it, note that this facility should not be used by anyone else
than the current ones.  Sysfs symlinks shouldn't be abused like this
and the whole thing doesn't belong in the block layer at all.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Milan Broz <mbroz@redhat.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-14 18:44:22 +01:00
Linus Torvalds 509e4aef44 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: Fix removal of extra drives when converting RAID6 to RAID5
  md: range check slot number when manually adding a spare.
  md/raid5: handle manually-added spares in start_reshape.
  md: fix sync_completed reporting for very large drives (>2TB)
  md: allow suspend_lo and suspend_hi to decrease as well as increase.
  md: Don't let implementation detail of curr_resync leak out through sysfs.
  md: separate meta and data devs
  md-new-param-to_sync_page_io
  md-new-param-to-calc_dev_sboffset
  md: Be more careful about clearing flags bit in ->recovery
  md: md_stop_writes requires mddev_lock.
  md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointer
  md: Ensure no IO request to get md device before it is properly initialised.
  md: Fix single printks with multiple KERN_<level>s
  md: fix regression resulting in delays in clearing bits in a bitmap
  md: fix regression with re-adding devices to arrays with no metadata
2011-01-13 17:30:20 -08:00
NeilBrown bf2cb0dab8 md: Fix removal of extra drives when converting RAID6 to RAID5
When a RAID6 is converted to a RAID5, the extra drive should
be discarded.  However it isn't due to a typo in a comparison.

This bug was introduced in commit e93f68a1fc in 2.6.35-rc4
and is suitable for any -stable since than.

As the extra drive is not removed, the 'degraded' counter is wrong and
so the RAID5 will not respond correctly to a subsequent failure.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown ba1b41b6b4 md: range check slot number when manually adding a spare.
When adding a spare to an active array, we should check the slot
number, but allow it to be larger than raid_disks if a reshape
is being prepared.

Apply the same test when adding a device to an
array-under-construction.  It already had most of the test in place,
but not quite all.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Rémi Rérolle 13ae864bc8 md: fix sync_completed reporting for very large drives (>2TB)
The values exported in the sync_completed file are unsigned long, which
overflows with very large drives, resulting in wrong values reported.

Since sync_completed uses sectors as unit, we'll start getting wrong
values with components larger than 2TB.

This patch simply replaces the use of unsigned long by unsigned long long.

Signed-off-by: Rémi Rérolle <rrerolle@lacie.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown 23ddff3792 md: allow suspend_lo and suspend_hi to decrease as well as increase.
The sysfs attributes 'suspend_lo' and 'suspend_hi' describe a region
to which read/writes are suspended so that the under lying data can be
manipulated without user-space noticing.
Currently the window they describe can only move forwards along the
device.  However this is an unnecessary restriction which will cause
problems with planned developments.
So relax this restriction and allow these endpoints to move
arbitrarily.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown 75d3da43cb md: Don't let implementation detail of curr_resync leak out through sysfs.
mddev->curr_resync has artificial values of '1' and '2' which are used
by the code which ensures only one resync is happening at a time on
any given device.

These values are internal and should never be exposed to user-space
(except when translated appropriately as in the 'pending' status in
/proc/mdstat).

Unfortunately they are as ->curr_resync is assigned to
->curr_resync_completed and that value is directly visible through
sysfs.

So change the assignments to ->curr_resync_completed to get the same
valued from elsewhere in a form that doesn't have the magic '1' or '2'
values.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow a6ff7e089c md: separate meta and data devs
Allow the metadata to be on a separate device from the
data.

This doesn't mean the data and metadata will by on separate
physical devices - it simply gives device-mapper and userspace
tools more flexibility.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow ccebd4c415 md-new-param-to_sync_page_io
Add new parameter to 'sync_page_io'.

The new parameter allows us to distinguish between metadata and data
operations.  This becomes important later when we add the ability to
use separate devices for data and metadata.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
Jonathan Brassow 57b2caa394 md-new-param-to-calc_dev_sboffset
When we allow for separate devices for data and metadata
in a later patch, we will need to be able to calculate
the superblock offset based on more than the bdev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown 7ebc0be7ff md: Be more careful about clearing flags bit in ->recovery
Setting ->recovery to 0 is generally not a good idea as it could clear
bits that shouldn't be cleared.  In particular, MD_RECOVERY_FROZEN
should only be cleared on explicit request from user-space.

So when we need to clear things, just clear the bits that need
clearing.

As there are a few different places which reap a resync process - and
some do an incomplte job - factor out the code for doing the from
md_check_recovery and call that function instead of open coding part
of it.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown defad61a5b md: md_stop_writes requires mddev_lock.
As md_stop_writes manipulates the sync_thread and calls md_update_sb,
it need to be called with mddev_lock held.

In all internal cases it is, but the symbol is exported for dm-raid to
call and in that case the lock won't be help.
Do make an exported version which takes the lock, and an internal
version which does not.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:33 +11:00
NeilBrown 0ca69886a8 md: Ensure no IO request to get md device before it is properly initialised.
When an md device is in the process of coming on line it is possible
for an IO request (typically a partition table probe) to get through
before the array is fully initialised, which can cause unexpected
behaviour (e.g. a crash).

So explicitly record when the array is ready for IO and don't allow IO
through until then.

There is no possibility for a similar problem when the array is going
off-line as there must only be one 'open' at that time, and it is busy
off-lining the array and so cannot send IO requests.  So no memory
barrier is needed in md_stop()

This has been a bug since commit 409c57f380 in 2.6.30 which
introduced md_make_request.  Before then, each personality would
register its own make_request_fn when it was ready.
This is suitable for any stable kernel from 2.6.30.y onwards.

Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by:  "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
2011-01-14 09:14:33 +11:00
NeilBrown 6c98791014 md: fix regression resulting in delays in clearing bits in a bitmap
commit 589a594be1 (2.6.37-rc4) fixed a problem were md_thread would
sometimes call the ->run function at a bad time.

If an error is detected during array start up after the md_thread has
been started, the md_thread is killed.  This resulted in the ->run
function being called once.  However the array may not be in a state
that it is safe to call ->run.

However the fix imposed meant that  ->run was not called on a timeout.
This means that when an array goes idle, bitmap bits do not get
cleared promptly.  While the array is busy the bits will still be
cleared when appropriate so this is not very serious.  There is no
risk to data.

Change the test so that we only avoid calling ->run when the thread
is being stopped.  This more explicitly addresses the problem situation.

This is suitable for 2.6.37-stable and any -stable kernel to which
589a594be1 was applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:13:53 +11:00
Linus Torvalds 275220f0fc Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...
2011-01-13 10:45:01 -08:00
NeilBrown bf572541ab md: fix regression with re-adding devices to arrays with no metadata
Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were
re-added when they shouldn't be but caused a regression in a less
common case that means sometimes devices cannot be re-added when they
should be.

In particular, when re-adding a device to an array without metadata
we should always access the device, but after the above commit we
didn't.

This patch sets the In_sync flag in that case so that the re-add
succeeds.

This patch is suitable for any -stable kernel to which 1a855a0606 was
applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-12 09:03:35 +11:00
Linus Torvalds 7f8635cc9e Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cciss: fix cciss_revalidate panic
  block: max hardware sectors limit wrapper
  block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
  blk-throttle: Correct the placement of smp_rmb()
  blk-throttle: Trim/adjust slice_end once a bio has been dispatched
  block: check for proper length of iov entries earlier in blk_rq_map_user_iov()
  drbd: fix for spin_lock_irqsave in endio callback
  drbd: don't recvmsg with zero length
2010-12-20 09:19:46 -08:00
Martin K. Petersen e692cb668f block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
When stacking devices, a request_queue is not always available. This
forced us to have a no_cluster flag in the queue_limits that could be
used as a carrier until the request_queue had been set up for a
metadevice.

There were several problems with that approach. First of all it was up
to the stacking device to remember to set queue flag after stacking had
completed. Also, the queue flag and the queue limits had to be kept in
sync at all times. We got that wrong, which could lead to us issuing
commands that went beyond the max scatterlist limit set by the driver.

The proper fix is to avoid having two flags for tracking the same thing.
We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
block layer merging functions. The queue_limit 'no_cluster' is turned
into 'cluster' to avoid double negatives and to ease stacking.
Clustering defaults to being enabled as before. The queue flag logic is
removed from the stacking function, and explicitly setting the cluster
flag is no longer necessary in DM and MD.

Reported-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17 08:35:53 +01:00
NeilBrown 589a594be1 md: protect against NULL reference when waiting to start a raid10.
When we fail to start a raid10 for some reason, we call
md_unregister_thread to kill the thread that was created.

Unfortunately md_thread() will then make one call into the handler
(raid10d) even though md_wakeup_thread has not been called.  This is
not safe and as md_unregister_thread is called after mddev->private
has been set to NULL, it will definitely cause a NULL dereference.

So fix this at both ends:
 - md_thread should only call the handler if THREAD_WAKEUP has been
   set.
 - raid10 should call md_unregister_thread before setting things
   to NULL just like all the other raid modules do.

This is applicable to 2.6.35 and later.

Cc: stable@kernel.org
Reported-by: "Citizen" <citizen_lee@thecus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 17:02:14 +11:00
NeilBrown 1a855a0606 md: fix bug with re-adding of partially recovered device.
With v0.90 metadata, a hot-spare does not become a full member of the
array until recovery is complete.  So if we re-add such a device to
the array, we know that all of it is as up-to-date as the event count
would suggest, and so it a bitmap-based recovery is possible.

However with v1.x metadata, the hot-spare immediately becomes a full
member of the array, but it record how much of the device has been
recovered.  If the array is stopped and re-assembled recovery starts
from this point.

When such a device is hot-added to an array we currently lose the 'how
much is recovered' information and incorrectly included it as a full
in-sync member (after bitmap-based fixup).
This is wrong and unsafe and could corrupt data.

So be more careful about setting saved_raid_disk - which is what
guides the re-adding of devices back into an array.
The new code matches the code in slot_store which does a similar
thing, which is encouraging.

This is suitable for any -stable kernel.

Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:36:28 +11:00
NeilBrown a035fc3e25 md: fix possible deadlock in handling flush requests.
As recorded in
    https://bugzilla.kernel.org/show_bug.cgi?id=24012

it is possible for a flush request through md to hang.  This is due to
an interaction between the recursion avoidance in
generic_make_request, the insistence in md of only having one flush
active at a time, and the possibility of dm (or md) submitting two
flush requests to a device from the one generic_make_request.

If a generic_make_request call into dm causes two flush requests to be
queued (as happens if the dm table has two targets - they get one
each), these two will be queued inside generic_make_request.

Assume they are for the same md device.
The first is processed and causes 1 or more flush requests to be sent
to lower devices.  These get queued within generic_make_request too.
Then the second flush to the md device gets handled and it blocks
waiting for the first flush to complete.  But it won't complete until
the two lower-device requests complete, and they haven't even been
submitted yet as they are on the generic_make_request queue.

The deadlock can be broken by using a separate thread to submit the
requests to lower devices.  md has such a thread readily available:
md_wq.

So use it to submit these requests.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Tested-by: Giacomo Catenazzi <cate@cateee.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:17:51 +11:00
NeilBrown a7a07e6965 md: move code in to submit_flushes.
submit_flushes is called from exactly one place.
Move the code that is before and after that call into
submit_flushes.

This has not functional change, but will make the next patch
smaller and easier to follow.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:04:25 +11:00
NeilBrown 2b74e12e56 md: remove handling of flush_pending in md_submit_flush_data
None of the functions called between setting flush_pending to 1, and
atomic_dec_and_test can change flush_pending, or will anything
running in any other thread (as ->flush_bio is not NULL).  So the
atomic_dec_and_test will always succeed.
So remove the atomic_sec and the atomic_dec_and_test.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 15:59:01 +11:00
Jens Axboe f30195c502 Merge branch 'cleanup-bd_claim' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into for-2.6.38/core 2010-11-27 19:49:18 +01:00
Darrick J. Wong be20e6c67b md: Call blk_queue_flush() to establish flush/fua support
Before 2.6.37, the md layer had a mechanism for catching I/Os with the
barrier flag set, and translating the barrier into barriers for all
the underlying devices.  With 2.6.37, I/O barriers have become plain
old flushes, and the md code was updated to reflect this.  However,
one piece was left out -- the md layer does not tell the block layer
that it supports flushes or FUA access at all, which results in md
silently dropping flush requests.

Since the support already seems there, just add this one piece of
bookkeeping.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:40:33 +11:00
Justin Maggard c26a44ed1e md: fix return value of rdev_size_change()
When trying to grow an array by enlarging component devices,
rdev_size_store() expects the return value of rdev_size_change() to be
in sectors, but the actual value is returned in KBs.

This functionality was broken by commit
     dd8ac336c1
so this patch is suitable for any kernel since 2.6.30.

Cc: stable@kernel.org
Signed-off-by: Justin Maggard <jmaggard10@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:36:17 +11:00
Tejun Heo d4d7762995 block: clean up blkdev_get() wrappers and their users
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:18 +01:00
Tejun Heo e525fd89d3 block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
Tejun Heo e09b457bdb block: simplify holder symlink handling
Code to manage symlinks in /sys/block/*/{holders|slaves} are overly
complex with multiple holder considerations, redundant extra
references to all involved kobjects, unused generic kobject holder
support and unnecessary mixup with bd_claim/release functionalities.

Strip it down to what's necessary (single gendisk holder) and make it
use a separate interface.  This is a step for cleaning up
bd_claim/release.  This patch makes dm-table slightly more complex but
it will be simplified again with further changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
2010-11-13 11:55:17 +01:00
Mike Snitzer 77304d2aba block: read i_size with i_size_read()
Convert direct reads of an inode's i_size to using i_size_read().

i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes.  Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}.  But
i_size_read() callers do not need to use additional locking.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10 14:40:53 +01:00
NeilBrown a167f66324 md: use separate bio pool for each md device.
bio_clone and bio_alloc allocate from a common bio pool.
If an md device is stacked with other devices that use this pool, or under
something like swap which uses the pool, then the multiple calls on
the pool can cause deadlocks.

So allocate a local bio pool for each md array and use that rather
than the common pool.

This pool is used both for regular IO and metadata updates.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:15 +11:00
NeilBrown 2b193363ef md: change type of first arg to sync_page_io.
Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:11 +11:00
Tejun Heo e804ac780e md: fix and update workqueue usage
Workqueue usage in md has two problems.

* Flush can be used during or depended upon by memory reclaim, but md
  uses the system workqueue for flush_work which may lead to deadlock.

* md depends on flush_scheduled_work() to achieve exclusion against
  completion of removal of previous instances.  flush_scheduled_work()
  may incur unexpected amount of delay and is scheduled to be removed.

This patch adds two workqueues to md - md_wq and md_misc_wq.  The
former is guaranteed to make forward progress under memory pressure
and serves flush_work.  The latter serves as the flush domain for
other works.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:29 +11:00
NeilBrown 4b532c9b8c md: remove md_mutex locking.
lock_kernel calls were recently pushed down into open/release
functions.
md doesn't need that protection.
Then the BKL calls were change to md_mutex.  We don't need those
either.
So remove it all.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:30:21 +11:00
NeilBrown d97a41dc9c md: Fix regression with raid1 arrays without persistent metadata.
A RAID1 which has no persistent metadata, whether internal or
external, will hang on the first write.
This is caused by commit  070dc6dd71
In that case, MD_CHANGE_PENDING never gets cleared.

So during md_update_sb, is neither persistent or external,
clear MD_CHANGE_PENDING.

This is suitable for 2.6.36-stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-10-28 17:30:20 +11:00
Linus Torvalds a2887097f2 Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...
2010-10-22 17:07:18 -07:00
Linus Torvalds c37927d435 Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  block: autoconvert trivial BKL users to private mutex
  drivers: autoconvert trivial BKL users to private mutex
  ipmi: autoconvert trivial BKL users to private mutex
  mac: autoconvert trivial BKL users to private mutex
  mtd: autoconvert trivial BKL users to private mutex
  scsi: autoconvert trivial BKL users to private mutex

Fix up trivial conflicts (due to addition of private mutex right next to
deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c
2010-10-22 10:49:54 -07:00
Jens Axboe fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Arnd Bergmann 2a48fc0ab2 block: autoconvert trivial BKL users to private mutex
The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.

This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-10-05 15:01:10 +02:00
NeilBrown ddcf3522cf md: fix v1.x metadata update when a disk is missing.
If an array with 1.x metadata is assembled with the last disk missing,
md doesn't properly record the fact that the disk was missing.

This is unlikely to cause a real problem as the event count will be
different to the count on the missing disk so it won't be included in
the array.  However it could still cause confusion.

So make sure we clear all the relevant slots, not just the early ones.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:28 +10:00
NeilBrown 126925c090 md: call md_update_sb even for 'external' metadata arrays.
Now that we depend on md_update_sb to clear variable bits in
mddev->flags (rather than trying not to set them) it is important to
always call md_update_sb when appropriate.

md_check_recovery has this job but explicitly avoids it for ->external
metadata arrays.  This is not longer appropraite, or needed.

However we do want to avoid taking the mddev lock if only
MD_CHANGE_PENDING is set as that is not cleared by md_update_sb for
external-metadata arrays.

Reported-by:  "Kwolek, Adam" <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:13 +10:00
Tejun Heo e9c7469bb4 md: implment REQ_FLUSH/FUA support
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER.  In the core part (md.c), the following
changes are notable.

* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
  processing of other requests and thus there is no reason to mark the
  queue congested while FLUSH/FUA is in progress.

* REQ_FLUSH/FUA failures are final and its users don't need retry
  logic.  Retry logic is removed.

* Preflush needs to be issued to all member devices but FUA writes can
  be handled the same way as other writes - their processing can be
  deferred to request_queue of member devices.  md_barrier_request()
  is renamed to md_flush_request() and simplified accordingly.

For linear, raid0 and multipath, the core changes are enough.  raid1,
5 and 10 need the following conversions.

* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
  request_queues of member devices.  Barrier related logic removed.

* raid5: Queue draining logic dropped.  FUA bit is propagated through
  biodrain and stripe resconstruction such that all the updated parts
  of the stripe are written out with FUA writes if any of the dirtying
  writes was FUA.  preread_active_stripes handling in make_request()
  is updated as suggested by Neil Brown.

* raid10: FUA bit needs to be propagated to write clones.

linear, raid0, 1, 5 and 10 tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
NeilBrown 070dc6dd71 md: resolve confusion of MD_CHANGE_CLEAN
MD_CHANGE_CLEAN is used for two different purposes and this leads to
confusion.
One of the purposes is largely mirrored by MD_CHANGE_PENDING which is
not used for anything else, so have MD_CHANGE_PENDING take over that
purpose fully.

The two purposes are:
 1/ tell md_update_sb that an update is needed and that it is just a
   clean/dirty transition.
 2/ tell user-space that an transition from clean to dirty is pending
    (something wants to write), and tell te kernel (by clearin the
    flag) that the transition is OK.

The first purpose remains wit MD_CHANGE_CLEAN, the second is moved
fully to MD_CHANGE_PENDING.

This means that various places which conditionally set or cleared
MD_CHANGE_CLEAN no longer need to be conditional.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:21 +10:00
Dan Williams bd52b74626 md: don't clear MD_CHANGE_CLEAN in md_update_sb() for external arrays
If this bit is cleared in md_update_sb() the kernel will allow writes to the
array if userspace triggers md_allow_write(), e.g. through stripe_cache_size,
when mdmon is not active.  When mdmon is active the array transitions to
active-idle bypassing write-pending, setting up a race for mdmon to set the
array clean before a write arrives.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:20 +10:00
NeilBrown 3a3a5ddb7a Update recovery_offset even when external metadata is used.
The update of ->recovery_offset in sync_sbs is appropriate even then external
metadata is in use.  However sync_sbs is only called when native
metadata is used.

So move that update in to the top of md_update_sb (which is the only
caller of sync_sbs) before the test on ->external.

This moves the update out of ->write_lock protection, but those fields
only need ->reconfig_mutex protection which they still have.

Also move the test on ->persistent up to where ->external is set as
for metadata update purposes they are the same.

Clear MD_CHANGE_DEVS and MD_CHANGE_CLEAN as they can only be confusing
if ->external is set or ->persistent isn't.

Finally move the update of ->utime down as it is only relevent (like
the ->events update) for native metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: "Kwolek, Adam" <adam.kwolek@intel.com>
2010-08-18 11:39:38 +10:00
Linus Torvalds 3d30701b58 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...
2010-08-10 15:38:19 -07:00
NeilBrown 6e17b02764 md: clean up do_md_stop
There is only one error exit from do_md_stop, so make that more
explicit and discard the 'err' variable.
Also drop the 'revalidate' variable by moving the unlock calls around.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:22:45 +10:00
NeilBrown bb4f1e9d0e md: fix another deadlock with removing sysfs attributes.
Move the deletion of sysfs attributes from reconfig_mutex to
open_mutex didn't really help as a process can try to take
open_mutex while holding reconfig_mutex, so the same deadlock can
happen, just requiring one more process to be involved in the chain.

I looks like I cannot easily use locking to wait for the sysfs
deletion to complete, so don't.

The only things that we cannot do while the deletions are still
pending is other things which can change the sysfs namespace: run,
takeover, stop.  Each of these can fail with -EBUSY.
So set a flag while doing a sysfs deletion, and fail run, takeover,
stop if that flag is set.

This is suitable for 2.6.35.x

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:21:27 +10:00
Dan Williams 147e0b6a63 md: move revalidate_disk() back outside open_mutex
Commit b821eaa5 "md: remove ->changed and related code" moved
revalidate_disk() under open_mutex, and lockdep noticed.

[ INFO: possible circular locking dependency detected ]
2.6.32-mdadm-locking #1
-------------------------------------------------------
mdadm/3640 is trying to acquire lock:
 (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811acecb>] revalidate_disk+0x5b/0x90

but task is already holding lock:
 (&mddev->open_mutex){+.+...}, at: [<ffffffffa055e07a>] do_md_stop+0x4a/0x4d0 [md_mod]

which lock already depends on the new lock.

It is suitable for 2.6.35.x

Cc: <stable@kernel.org>
Reported-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:20:17 +10:00
Arnd Bergmann 6e9624b8ca block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:25:34 +02:00
Christoph Hellwig 7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00
NeilBrown 69e51b449d md/bitmap: separate out loading a bitmap from initialising the structures.
dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown b63d7c2e29 md/bitmap: clean up plugging calls.
1/ use md_unplug in bitmap.c as we will soon be using bitmaps under
  arrays with no queue attached.

2/ Don't bother plugging the queue when we set a bit in the bitmap.
   The reason for this was to encourage as many bits as possible to
   get set before we unplug and write stuff out.
   However every personality already plugs the queue after
   bitmap_startwrite either directly (raid1/raid10) or be setting
   STRIPE_BIT_DELAY which causes the queue to be plugged later
   (raid5).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown 252ac5221a md/plug: optionally use plugger to unplug an array during resync/recovery.
If an array doesn't have a 'queue' then md_do_sync cannot
unplug it.
In that case it will have a 'plugger', so make that available
to the mddev, and use it to unplug the array if needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown 2ac8740151 md/raid5: add simple plugging infrastructure.
md/raid5 uses the plugging infrastructure provided by the block layer
and 'struct request_queue'.  However when we plug raid5 under dm there
is no request queue so we cannot use that.

So create a similar infrastructure that is much lighter weight and use
it for raid5.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown 768a418db1 md: add support for raising dm events.
dm uses scheduled work to raise events to user-space.
So allow md device to have work_structs and schedule them on an error.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 390ee602a1 md: export various start/stop interfaces
export entry points for starting and stopping md arrays.
This will be used by a module to make md/raid5 work under
dm.
Also stop calling md_stop_writes from md_stop, as that won't
work well with dm - it will want to call the two separately.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown e8bb9a839a md: split out md_rdev_init
This functionality will be needed separately in a subsequent patch, so
split it into it's own exported function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 676e42d896 md: be more careful setting MD_CHANGE_CLEAN
When MD_CHANGE_CLEAN is set we might block in md_write_start.
So we should only set it when fairly sure that something will clear
it.

There are two places where it is set so as to encourage a metadata
update to record the progress of resync/recovery.  This should only
be done if the internal metadata update mechanisms are in use, which
can be tested by by inspecting '->persistent'.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown 00bcb4ac7e md: reduce dependence on sysfs.
We will want md devices to live as dm targets where sysfs is not
visible.  So allow md to not connect to sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-21 13:27:53 +10:00
NeilBrown 70fffd0bfa md: Don't update ->recovery_offset when reshaping an array to fewer devices.
When an array is reshaped to have fewer devices, the reshape proceeds
from the end of the devices to the beginning.

If a device happens to be non-In_sync (which is possible but rare)
we would normally update the ->recovery_offset as the reshape
progresses. However that would be wrong as the recover_offset records
that the early part of the device is in_sync, while in fact it would
only be the later part that is in_sync, and in any case the offset
number would be measured from the wrong end of the device.

Relatedly, if after a reshape a spare is discovered to not be
recoverred all the way to the end, not allow spare_active
to incorporate it in the array.

This becomes relevant in the following sample scenario:

A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined
operation.
The RAID5->RAID6 conversion will cause a 5 drive to be included as a
spare, then the 5drive -> 6drive reshape will effectively rebuild that
spare as it progresses.  The 6th drive is treated as in_sync the whole
time as there is never any case that we might consider reading from
it, but must not because there is no valid data.

If we interrupt this reshape part-way through and reverse it to return
to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update
the recovery_offset - as that would be wrong - and we don't want to
include that spare as active in the 5-drive RAID6 when the reversed
reshape completed and it will be mostly out-of-sync still.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:18 +10:00
NeilBrown e93f68a1fc md: fix handling of array level takeover that re-arranges devices.
Most array level changes leave the list of devices largely unchanged,
possibly causing one at the end to become redundant.
However conversions between RAID0 and RAID10 need to renumber
all devices (except 0).

This renumbering is currently being done in the ->run method when the
new personality takes over.  However this is too late as the common
code in md.c might already have invalidated some of the devices if
they had a ->raid_disk number that appeared to high.

Moving it into the ->takeover method is too early as the array is
still active at that time and wrong ->raid_disk numbers could cause
confusion.

So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate
the new raid_disk number.
Now the common code knows exactly which devices need to be renumbered,
and which can be invalidated, and can do it all at a convenient time
when the array is suspend.
It can also update some symlinks in sysfs which previously were not be
updated correctly.

Reported-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:33:24 +10:00
NeilBrown f3b99be19d Restore partition detection of newly created md arrays.
Commit  b821eaa572 broke partition
detection for md arrays.

The logic was almost right.  However if revalidate_disk is called
when the device is not yet open, bdev->bd_disk won't be set, so the
flush_disk() Call will not set bd_invalidated.

So when md_open is called we still need to ensure that
->bd_invalidated gets set.  This is easily done with a call to
check_disk_size_change in the place where the offending commit removed
check_disk_change.  At the important times, the size will have changed
from 0 to non-zero, so check_disk_size_change will set bd_invalidated.

Tested-by: Duncan <1i5t5.duncan@cox.net>
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:31:03 +10:00
NeilBrown 19fdb9eefb Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linus
Conflicts:
	drivers/md/md.c

- Resolved conflict in md_update_sb
- Added extra 'NULL' arg to new instance of sysfs_get_dirent.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-22 08:31:36 +10:00
Eric W. Biederman 3ff195b011 sysfs: Implement sysfs tagged directory support.
The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
NeilBrown be6800a73a md: don't insist on valid event count for spare devices.
Devices which know that they are spares do not really need to have
an event count that matches the rest of the array, so there are no
data-in-sync issues. It is enough that the uuid matches.
So remove the requirement that the event count is up-to-date.

We currently still write out and event count on spares, but this
allows us in a year or 3 to stop doing that completely.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
NeilBrown a8707c08f4 md: simplify updating of event count to sometimes avoid updating spares.
When updating the event count for a simple clean <-> dirty transition,
we try to avoid updating the spares so they can safely spin-down.
As the event_counts across an array must be +/- 1, this means
decrementing the event_count on a dirty->clean transition.
This is not always safe and we have to avoid the unsafe time.
We current do this with a misguided idea about it being safe or
not depending on whether the event_count is odd or even.  This
approach only works reliably in a few common instances, but easily
falls down.

So instead, simply keep internal state concerning whether it is safe
or not, and always assume it is not safe when an array is first
assembled.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
NeilBrown 75a73a29e5 md: restore ability of spare drives to spin down.
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down.  Device failure/removal
etc are still recorded on spares.

However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:

   This means that the alignment between 'odd/even' and
    'clean/dirty' might take a little longer to attain,

how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.

So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately.  There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update).  We just piggy-back on that.

Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-18 15:28:00 +10:00
Dan Williams f2859af671 md: allow integers to be passed to md/level
e.g. allow md to interpret 'echo 4 > md/level' as a request for raid4.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:58 +10:00
Dan Williams bb7f8d2217 md: notify mdstat waiters of level change
Level modifications change the output of mdstat.  The mdmon manager
thread is interested in these events for external metadata management.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:57 +10:00
NeilBrown 9e35b99c7e md: don't unregister the thread in mddev_suspend
This is
 - unnecessary because mddev_suspend is always followed by a call to
   ->stop, and each ->stop unregisters the thread, and
 - a problem as it makes it awkwards to suspend and then resume a
   device as we will want later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:56 +10:00
NeilBrown fafd7fb052 md: factor out init code for an mddev
This is a simple factorisation that makes mddev_find easier to read.


Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown 21a52c6d05 md: pass mddev to make_request functions rather than request_queue
We used to pass the personality make_request function direct
to the block layer so the first argument had to be a queue.
But now we have the intermediary md_make_request so it makes
at lot more sense to pass a struct mddev_s.
It makes it possible to have an mddev without its own queue too.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown cca9cf90c5 md: call md_stop_writes from md_stop
This moves the call to the other side of set_readonly, but that should
not be an issue.
This encapsulates in 'md_stop' all of the functionality for internally
stopping the array, leaving all the interactions with externalities
(sysfs, request_queue, gendisk) in do_md_stop.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown a4bd82d0d0 md: split md_set_readonly out of do_md_stop
Using do_md_stop to set an array to read-only is a little confusing.
Now most of the common code has been factored out, split
md_set_readonly off in to a separate function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown a047e12540 md: factor md_stop_writes out of do_md_stop.
Further refactoring of do_md_stop.
This one requires some explanation as it takes code from different
places in do_md_stop, so some re-ordering happens.

We only get into this part of do_md_stop if there are no active opens
of the device, so no writes can be happening and the device must have
been flushed.  In md_stop_writes we want to stop any internal sources
of writes - i.e. resync - and flush out the metadata.

The only code that was previously before some of this code is
code to clean up the queue, the mddev, the gendisk, or sysfs, all
of which is probably better after code that makes active changes (i.e.
triggers writes).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown 6177b472ab md: start to refactor do_md_stop
do_md_stop is large and clunky, so hard to understand.

This is a first step of refactoring, pulling two simple
sub-functions out.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown fe60b01428 md: factor do_md_run to separate accesses to ->gendisk
As part of relaxing the binding between an mddev and gendisk,
we separate do_md_run into two functions.
  md_run does all the work internal to md
  do_md_run calls md_run and makes and changes to gendisk
     that are required.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown b821eaa572 md: remove ->changed and related code.
We set ->changed to 1 and call check_disk_change at the end
of md_open so that bd_invalidated would be set and thus
partition rescan would happen appropriately.

Now that we call revalidate_disk directly, which sets bd_invalidates,
that indirection is no longer needed and can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown 49ce6cea85 md: don't reference gendisk in getgeo
Using ->array_sectors rather than get_capacity() is more
direct and is a step towards relaxing the tight connection
between mddev and gendisk.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
NeilBrown 490773268c md: move io accounting out of personalities into md_make_request
While I generally prefer letting personalities do as much as possible,
given that we have a central md_make_request anyway we may as well use
it to simplify code.
Also this centralises knowledge of ->gendisk which will help later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
Maciej Trela 5cac7861b2 md: notify level changes through sysfs.
Level changes can be very significant, so make sure
to notify them via sysfs.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00
NeilBrown 233fca36bb md: Relax checks on ->max_disks when external metadata handling is used.
When metadata is being managed by user-space, md doesn't know
what the maximum number of devices allowed in an array is
so ->max_disks is 0.  In this case we should allow any (+ve)
number of disks.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00
Maciej Trela b71031076e md: Correctly handle device removal via sysfs
Writing "none" to "../md/dev-xx/slot" removes that device
from being an active part of the array, but it didn't
set ->raid_disk to -1 to record this fact.


Signed-off-by: Maciej Trela <Maciej.Trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
Trela, Maciej 9af204cf72 md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
Trela Maciej 54071b3808 md:Add support for Raid0->Raid5 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
NeilBrown c0cc75f84e md: discard StateChanged device flag.
This was needed when sysfs files could only be 'notified'
from process context.  Now that we have sys_notify_direct,
we can call it directly from an interrupt.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
NeilBrown a64c876fd3 md: manage redundancy group in sysfs when changing level.
Some levels expect the 'redundancy group' to be present,
others don't.
So when we change level of an array we might need to
add or remove this group.

This requires fixing up the current practice of overloading ->private
to indicate (when ->pers == NULL) that something needs to be removed.
So create a new ->to_remove to fill that role.

When changing levels, we may need to add or remove attributes.  When
changing RAID5 -> RAID6, we both add and remove the same thing.  It is
important to catch this and optimise it out as the removal is delayed
until a lock is released, so trying to add immediately would cause
problems.


Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17 14:45:40 +10:00
NeilBrown b6eb127d27 md: remove unneeded sysfs files more promptly
When an array is stopped we need to remove some
sysfs files which are dependent on the type of array.

We need to delay that deletion as deleting them while holding
reconfig_mutex can lead to deadlocks.

We currently delay them until the array is completely destroyed.
However it is possible to deactivate and then reactivate the array.
It is also possible to need to remove sysfs files when changing level,
which can potentially happen several times before an array is
destroyed.

So we need to delete these files more promptly: as soon as
reconfig_mutex is dropped.

We need to ensure this happens before do_md_run can restart the array,
so we use open_mutex for some extra locking.  This is not deadlock
prone.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17 14:40:07 +10:00
Dan Williams e221835046 md: set mddev readonly flag on blkdev BLKROSET ioctl
When the user sets the block device to readwrite then the mddev should
follow suit.  Otherwise, the BUG_ON in md_write_start() will be set to
trigger.

The reverse direction, setting mddev->ro to match a set readonly
request, can be ignored because the blkdev level readonly flag precludes
the need to have mddev->ro set correctly.  Nevermind the fact that
setting mddev->ro to 1 may fail if the array is in use.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-12 08:25:37 +10:00
NeilBrown 1176568de7 md: restore ability of spare drives to spin down.
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down.  Device failure/removal
etc are still recorded on spares.

However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:

   This means that the alignment between 'odd/even' and
    'clean/dirty' might take a little longer to attain,

how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.

So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately.  There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update).  We just piggy-back on that.

Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-07 21:10:57 +10:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Emese Revfy 52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
NeilBrown ef286f6fa6 md: fix some lockdep issues between md and sysfs.
======
This fix is related to
    http://bugzilla.kernel.org/show_bug.cgi?id=15142
but does not address that exact issue.
======

sysfs does like attributes being removed while they are being accessed
(i.e. read or written) and waits for the access to complete.

As accessing some md attributes takes the same lock that is held while
removing those attributes a deadlock can occur.

This patch addresses 3 issues in md that could lead to this deadlock.

Two relate to calling flush_scheduled_work while the lock is held.
This is probably a bad idea in general and as we use schedule_work to
delete various sysfs objects it is particularly bad.

In one case flush_scheduled_work is called from md_alloc (called by
md_probe) called from do_md_run which holds the lock.  This call is
only present to ensure that ->gendisk is set.  However we can be sure
that gendisk is always set (though possibly we couldn't when that code
was originally written.  This is because do_md_run is called in three
different contexts:
  1/ from md_ioctl.  This requires that md_open has succeeded, and it
     fails if ->gendisk is not set.
  2/ from writing a sysfs attribute.  This can only happen if the
     mddev has been registered in sysfs which happens in md_alloc
     after ->gendisk has been set.
  3/ from autorun_array which is only called by autorun_devices, which
     checks for ->gendisk to be set before calling autorun_array.
So the call to md_probe in do_md_run can be removed, and the check on
->gendisk can also go.


In the other case flush_scheduled_work is being called in do_md_stop,
purportedly to wait for all md_delayed_delete calls (which delete the
component rdevs) to complete.  However there really isn't any need to
wait for them - they have already been disconnected in all important
ways.

The third issue is that raid5->stop() removes some attribute names
while the lock is held.  There is already some infrastructure in place
to delay attribute removal until after the lock is released (using
schedule_work).  So extend that infrastructure to remove the
raid5_attrs_group.

This does not address all lockdep issues related to the sysfs
"s_active" lock.  The rest can be address by splitting that lockdep
context between symlinks and non-symlinks which hopefully will happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-02-10 11:26:09 +11:00
NeilBrown 404e4b43fd md: allow a resync that is waiting for other resync to complete, to be aborted.
If two arrays share a device, then they will not both resync at the
same time.  One will wait for the other to complete.
While waiting, the MD_RECOVERY_INTR flag is not checked so a device
failure, which would make the resync pointless, does not cause the
resync to abort, so the failed device cannot be removed (as it cannot
be remove while a resync is happening).

So add a test for MD_RECOVERY_INTR.

Reported-by: Brett Russ <bruss@netezza.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:25:23 +11:00
NeilBrown 7fb9dadc91 md: remove unnecessary code from do_md_run
Since commit dfc7064500,
->hot_remove_disks has not removed non-failed devices from
an array until recovery is no longer possible.
So the code in do_md_run to get around the fact that
md_check_recovery (which calls ->hot_remove_disks) would
remove partially-in-sync devices is no longer needed.

So remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:43 +11:00
Dan Williams a2d79c324a md: make recovery started by do_md_run() visible via sync_action
By default md_do_sync() will perform recovery if no other actions are
specified.  However, action_show() relies on MD_RECOVERY_RECOVER to be
set otherwise it returns 'idle'.  So, add a missing set
MD_RECOVERY_RECOVER when starting recovery.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:31 +11:00
NeilBrown 0f9552b5dc md: fix small irregularity with start_ro module parameter
The start_ro modules parameter can be used to force arrays to be
started in 'auto-readonly' in which they are read-only until the first
write.  This ensures that no resync/recovery happens until something
else writes to the device.  This is important for resume-from-disk
off an md array.

However if an array is started 'readonly' (by writing 'readonly' to
the 'array_state' sysfs attribute) we want it to be really 'readonly',
not 'auto-readonly'.

So strengthen the condition to only set auto-readonly if the
array is not already read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:12 +11:00
NeilBrown cbd1998377 md: Fix unfortunate interaction with evms
evms configures md arrays by:
  open device
  send ioctl
  close device

for each different ioctl needed.
Since 2.6.29, the device can disappear after the 'close'
unless a significant configuration has happened to the device.
The change made by "SET_ARRAY_INFO" can too minor to stop the device
from disappearing, but important enough that losing the change is bad.

So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device
active as long as ctime is non-zero (it gets zeroed with lots of other
things when the array is stopped).

This is suitable for -stable kernels since 2.6.29.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-30 12:08:49 +11:00
Joe Perches 7b75c2f8cf drivers/md/md.c: use %pU to print UUIDs
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:33 -08:00
André Goddard Rosa e7d2860b69 tree-wide: convert open calls to remove spaces to skip_spaces() lib function
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
Dan Williams 06e3c817b7 md: add 'recovery_start' per-device sysfs attribute
Enable external metadata arrays to manage rebuild checkpointing via a
md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset

Also update resync_start_store to allow 'none' to be written, for
consistency.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:58:57 +11:00