Commit graph

759 commits

Author SHA1 Message Date
Ilya Dryomov d147543d79 rbd: store rbd_options in rbd_device
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-06-25 18:30:55 +03:00
Ilya Dryomov 210c104c54 rbd: terminate rbd_opts_tokens with Opt_err
Also nuke useless Opt_last_bool and don't break lines unnecessarily.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-06-25 18:30:54 +03:00
Ilya Dryomov d3834fefcf rbd: bump queue_max_segments
The default queue_limits::max_segments value (BLK_MAX_SEGMENTS = 128)
unnecessarily limits bio sizes to 512k (assuming 4k pages).  rbd, being
a virtual block device, doesn't have any restrictions on the number of
physical segments, so bump max_segments to max_hw_sectors, in theory
allowing a sector per segment (although the only case this matters that
I can think of is some readv/writev style thing).  In practice this is
going to give us 1M bios - the number of segments in a bio is limited
in bio_get_nr_vecs() by BIO_MAX_PAGES = 256.

Note that this doesn't result in any improvement on a typical direct
sequential test.  This is because on a box with a not too badly
fragmented memory the default BLK_MAX_SEGMENTS is enough to see nice
rbd object size sized requests.  The only difference is the size of
bios being merged - 512k vs 1M for something like

    $ dd if=/dev/zero of=/dev/rbd0 oflag=direct bs=$RBD_OBJ_SIZE
    $ dd if=/dev/rbd0 iflag=direct of=/dev/null bs=$RBD_OBJ_SIZE

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-06-25 18:30:49 +03:00
Ilya Dryomov 2894e1d769 rbd: timeout watch teardown on unmap with mount_timeout
As part of unmap sequence, kernel client has to talk to the OSDs to
teardown watch on the header object.  If none of the OSDs are available
it would hang forever, until interrupted by a signal - when that
happens we follow through with the rest of unmap procedure (i.e.
unregister the device and put all the data structures) and the unmap is
still considired successful (rbd cli tool exits with 0).  The watch on
the userspace side should eventually timeout so that's fine.

This isn't very nice, because various userspace tools (pacemaker rbd
resource agent, for example) then have to worry about setting up their
own timeouts.  Timeout it with mount_timeout (60 seconds by default).

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Sage Weil <sage@redhat.com>
2015-06-25 11:49:30 +03:00
Ilya Dryomov a319bf56a6 libceph: store timeouts in jiffies, verify user input
There are currently three libceph-level timeouts that the user can
specify on mount: mount_timeout, osd_idle_ttl and osdkeepalive.  All of
these are in seconds and no checking is done on user input: negative
values are accepted, we multiply them all by HZ which may or may not
overflow, arbitrarily large jiffies then get added together, etc.

There is also a bug in the way mount_timeout=0 is handled.  It's
supposed to mean "infinite timeout", but that's not how wait.h APIs
treat it and so __ceph_open_session() for example will busy loop
without much chance of being interrupted if none of ceph-mons are
there.

Fix all this by verifying user input, storing timeouts capped by
msecs_to_jiffies() in jiffies and using the new ceph_timeout_jiffies()
helper for all user-specified waits to handle infinite timeouts
correctly.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-06-25 11:49:29 +03:00
Yan, Zheng 144cba1493 libceph: allow setting osd_req_op's flags
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-06-25 11:49:27 +03:00
Ilya Dryomov 082a75dad8 rbd: end I/O the entire obj_request on error
When we end I/O struct request with error, we need to pass
obj_request->length as @nr_bytes so that the entire obj_request worth
of bytes is completed.  Otherwise block layer ends up confused and we
trip on

    rbd_assert(more ^ (which == img_request->obj_request_count));

in rbd_img_obj_callback() due to more being true no matter what.  We
already do it in most cases but we are missing some, in particular
those where we don't even get a chance to submit any obj_requests, due
to an early -ENOMEM for example.

A number of obj_request->xferred assignments seem to be redundant but
I haven't touched any of obj_request->xferred stuff to keep this small
and isolated.

Cc: Alex Elder <elder@linaro.org>
Cc: stable@vger.kernel.org # 3.10+
Reported-by: Shawn Edwards <lesser.evil@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2015-05-01 16:44:30 -07:00
Ilya Dryomov f77303bdda rbd: rbd_wq comment is obsolete
After the switch to blk-mq rbd_wq processes requests, not devices.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2015-04-22 18:33:49 +03:00
Ilya Dryomov d8a2c89c86 rbd: mark block queue as non-rotational
Set QUEUE_FLAG_NONROT.  Following commit b277da0a8a ("block: disable
entropy contributions for nonrot devices") we should also clear
QUEUE_FLAG_ADD_RANDOM, but it's off by default for blk-mq drivers, so
just note it in the comment.

Also remove physical block size assignment - no sense in repeating
defaults that are not going to change.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2015-04-20 18:55:38 +03:00
Ilya Dryomov 1fe480235a rbd: be more informative on -ENOENT failures
pr_info what exactly was the culprit: missing pool, image or snap.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2015-04-20 18:55:33 +03:00
Christoph Hellwig 7ad18afad0 rbd: convert to blk-mq
This converts the rbd driver to use the blk-mq infrastructure.  Except
for switching to a per-request work item this is almost mechanical.

This was tested by Alexandre DERUMIER in November, and found to give
him 120000 iops, although the only comparism available was an old
3.10 kernel which gave 80000iops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <elder@linaro.org>
[idryomov@gmail.com: context, blk_mq_init_queue() EH]
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2015-02-19 14:27:42 +03:00
Ilya Dryomov cf32bd9c86 rbd: do not treat standalone as flatten
If the clone is resized down to 0, it becomes standalone.  If such
resize is carried over while an image is mapped we would detect this
and call rbd_dev_parent_put() which means "let go of all parent state,
including the spec(s) of parent images(s)".  This leads to a mismatch
between "rbd info" and sysfs parent fields, so a fix is in order.

    # rbd create --image-format 2 --size 1 foo
    # rbd snap create foo@snap
    # rbd snap protect foo@snap
    # rbd clone foo@snap bar
    # DEV=$(rbd map bar)
    # rbd resize --allow-shrink --size 0 bar
    # rbd resize --size 1 bar
    # rbd info bar | grep parent
            parent: rbd/foo@snap

Before:

    # cat /sys/bus/rbd/devices/0/parent
    (no parent image)

After:

    # cat /sys/bus/rbd/devices/0/parent
    pool_id 0
    pool_name rbd
    image_id 10056b8b4567
    image_name foo
    snap_id 2
    snap_name snap
    overlap 0

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-02-19 13:31:39 +03:00
Ilya Dryomov 73e39e4dba rbd: fix error paths in rbd_dev_refresh()
header_rwsem should be released on errors.  Also remove useless
rbd_dev->mapping.size != rbd_dev->header.image_size test.

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2015-02-19 13:31:38 +03:00
Rickard Strandqvist 3a25cf43e0 rbd: nuke copy_token()
It's been largely superseded by dup_token() and unused for over
2 years, identified by cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
[idryomov@redhat.com: changelog]
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2015-02-19 13:31:38 +03:00
Ilya Dryomov e69b8d414f rbd: drop parent_ref in rbd_dev_unprobe() unconditionally
This effectively reverts the last hunk of 392a9dad7e ("rbd: detect
when clone image is flattened").

The problem with parent_overlap != 0 condition is that it's possible
and completely valid to have an image with parent_overlap == 0 whose
parent state needs to be cleaned up on unmap.  The next commit, which
drops the "clone image now standalone" logic, opens up another window
of opportunity to hit this, but even without it

    # cat parent-ref.sh
    #!/bin/bash
    rbd create --image-format 2 --size 1 foo
    rbd snap create foo@snap
    rbd snap protect foo@snap
    rbd clone foo@snap bar
    rbd resize --allow-shrink --size 0 bar
    rbd resize --size 1 bar
    DEV=$(rbd map bar)
    rbd unmap $DEV

leaves rbd_device/rbd_spec/etc and rbd_client along with ceph_client
hanging around.

My thinking behind calling rbd_dev_parent_put() unconditionally is that
there shouldn't be any requests in flight at that point in time as we
are deep into unmap sequence.  Hence, even if rbd_dev_unparent() caused
by flatten is delayed by in-flight requests, it will have finished by
the time we reach rbd_dev_unprobe() caused by unmap, thus turning
unconditional rbd_dev_parent_put() into a no-op.

Fixes: http://tracker.ceph.com/issues/10352

Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-01-28 16:12:02 +03:00
Ilya Dryomov ae43e9d05e rbd: fix rbd_dev_parent_get() when parent_overlap == 0
The comment for rbd_dev_parent_get() said

    * We must get the reference before checking for the overlap to
    * coordinate properly with zeroing the parent overlap in
    * rbd_dev_v2_parent_info() when an image gets flattened.  We
    * drop it again if there is no overlap.

but the "drop it again if there is no overlap" part was missing from
the implementation.  This lead to absurd parent_ref values for images
with parent_overlap == 0, as parent_ref was incremented for each
img_request and virtually never decremented.

Fix this by leveraging the fact that refresh path calls
rbd_dev_v2_parent_info() under header_rwsem and use it for read in
rbd_dev_parent_get(), instead of messing around with atomics.  Get rid
of barriers in rbd_dev_v2_parent_info() while at it - I don't see what
they'd pair with now and I suspect we are in a pretty miserable
situation as far as proper locking goes regardless.

Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2015-01-28 16:11:51 +03:00
Ilya Dryomov 7e868b6eff rbd: don't treat CEPH_OSD_OP_DELETE as extent op
CEPH_OSD_OP_DELETE is not an extent op, stop treating it as such.  This
sneaked in with discard patches - it's one of the three osd ops (the
other two are CEPH_OSD_OP_TRUNCATE and CEPH_OSD_OP_ZERO) that discard
is implemented with.

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-12-17 20:09:51 +03:00
SF Markus Elfring e96a650a81 ceph, rbd: delete unnecessary checks before two function calls
The functions ceph_put_snap_context() and iput() test whether their
argument is NULL and then return immediately. Thus the test around the
call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[idryomov@redhat.com: squashed rbd.c hunk, changelog]
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17 20:09:50 +03:00
Jan Kara a8d4205623 rbd: Fix error recovery in rbd_obj_read_sync()
When we fail to allocate page vector in rbd_obj_read_sync() we just
basically ignore the problem and continue which will result in an oops
later. Fix the problem by returning proper error.

CC: Yehuda Sadeh <yehuda@inktank.com>
CC: Sage Weil <sage@inktank.com>
CC: ceph-devel@vger.kernel.org
CC: stable@vger.kernel.org
Coverity-id: 1226882
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2014-10-30 13:11:51 +03:00
Ilya Dryomov f5ee37bd31 rbd: use a single workqueue for all devices
Using one queue per device doesn't make much sense given that our
workfn processes "devices" and not "requests".  Switch to a single
workqueue for all devices.

Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2014-10-30 13:11:25 +03:00
Ilya Dryomov 792c3a9149 rbd: rbd workqueues need a resque worker
Need to use WQ_MEM_RECLAIM for our workqueues to prevent I/O lockups
under memory pressure - we sit on the memory reclaim path.

Cc: stable@vger.kernel.org # 3.17, needs backporting for 3.16
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
Tested-by: Micha Krause <micha@krausam.de>
Reviewed-by: Sage Weil <sage@redhat.com>
2014-10-14 12:57:05 -07:00
Josh Durgin b76f82398c rbd: set the remaining discard properties to enable support
max_discard_sectors must be set for the queue to support discard.
Operations implementing discard for rbd zero data, so report that.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:37 +04:00
Josh Durgin d3246fb0da rbd: use helpers to handle discard for layered images correctly
Only allocate two osd ops for discard requests, since the
preallocation hint is only added for regular writes.  Use
rbd_img_obj_request_fill() to recreate the original write or discard
osd operations, isolating that logic to one place, and change the
assert in rbd_osd_req_create_copyup() to accept discard requests as
well.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:36 +04:00
Josh Durgin 3b434a2aff rbd: extract a method for adding object operations
rbd_img_request_fill() creates a ceph_osd_request and has logic for
adding the appropriate osd ops to it based on the request type and
image properties.

For layered images, the original rbd_obj_request is resent with a
copyup operation in front, using a new ceph_osd_request. The logic for
adding the original operations should be the same as when first
sending them, so move it to a helper function.

op_type only needs to be checked once, so create a helper for that as
well and call it outside the loop in rbd_img_request_fill().

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:35 +04:00
Josh Durgin 1c220881e3 rbd: make discard trigger copy-on-write
Discard requests are a form of write, so they should go through the
same process as plain write requests and trigger copy-on-write for
layered images.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:34 +04:00
Josh Durgin d0265de7c3 rbd: tolerate -ENOENT for discard operations
Discard may try to delete an object from a non-layered image that does not exist.
If this occurs, the image already has no data in that range, so change the
result to success.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:33 +04:00
Josh Durgin bef95455a4 rbd: fix snapshot context reference count for discards
Discards take a reference to the snapshot context of an image when
they are created.  This reference needs to be cleaned up when the
request is done just as it is for regular writes.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:32 +04:00
Josh Durgin 3c5df89367 rbd: read image size for discard check safely
In rbd_img_request_fill() the image size is only checked to determine
whether we can truncate an object instead of zeroing it for discard
requests. Take rbd_dev->header_rwsem while reading the image size, and
move this read into the discard check, so that non-discard ops don't
need to take the semaphore in this function.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:32 +04:00
Guangliang Zhao 90e98c5229 rbd: initial discard bits from Guangliang Zhao
This patch add the discard support for rbd driver.

There are three types operation in the driver:
1. The objects would be removed if they completely contained
   within the discard range.
2. The objects would be truncated if they partly contained within
   the discard range, and align with their boundary.
3. Others would be zeroed.

A discard request from blkdev_issue_discard() is defined which
REQ_WRITE and REQ_DISCARD both marked and no data, so we must
check the REQ_DISCARD first when getting the request type.

This resolve:
	http://tracker.ceph.com/issues/190

[ Ilya Dryomov: This is incomplete and somewhat buggy, see follow up
  commits by Josh Durgin for refinements and fixes which weren't
  folded in to preserve authorship. ]

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-10-14 21:03:31 +04:00
Guangliang Zhao 6d2940c881 rbd: extend the operation type
It could only handle the read and write operations now,
extend it for the coming discard support.

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-10-14 21:03:30 +04:00
Guangliang Zhao c622d22615 rbd: skip the copyup when an entire object writing
It need to copyup the parent's content when layered writing,
but an entire object write would overwrite it, so skip it.

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-10-14 21:03:29 +04:00
Ilya Dryomov 70d045f660 rbd: add img_obj_request_simple() helper
To clarify the conditions and make it easier to add new ones.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-10-14 21:03:28 +04:00
Josh Durgin 4e752f0ab0 rbd: access snapshot context and mapping size safely
These fields may both change while the image is mapped if a snapshot
is created or deleted or the image is resized.  They are guarded by
rbd_dev->header_rwsem, so hold that while reading them, and store a
local copy to refer to outside of the critical section. The local copy
will stay consistent since the snapshot context is reference counted,
and the mapping size is just a u64. This prevents torn loads from
giving us inconsistent values.

Move reading header.snapc into the caller of rbd_img_request_create()
so that we only need to take the semaphore once. The read-only caller,
rbd_parent_request_create() can just pass NULL for snapc, since the
snapshot context is only relevant for writes.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
2014-10-14 21:03:27 +04:00
Ilya Dryomov 7dd440c9e0 rbd: do not return -ERANGE on auth failures
Trying to map an image out of a pool for which we don't have an 'x'
permission bit fails with -ERANGE from ceph_extract_encoded_string()
due to an unsigned vs signed bug.  Fix it and get rid of the -EINVAL
sink, thus propagating rbd::get_id cls method errors.  (I've seen
a bunch of unexplained -ERANGE reports, I bet this is it).

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-10-14 21:03:26 +04:00
Wei Yongjun 255939e783 rbd: fix error return code in rbd_dev_device_setup()
Fix to return -ENOMEM from the workqueue alloc error handling
case instead of 0, as done elsewhere in this function.

Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
2014-09-10 11:59:06 +04:00
Ilya Dryomov 58d1362b50 rbd: avoid format-security warning inside alloc_workqueue()
drivers/block/rbd.c: In function ‘rbd_dev_device_setup’:
drivers/block/rbd.c:5090:19: warning: format not a string literal and no format arguments [-Wformat-security]

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-09-10 11:59:06 +04:00
Ilya Dryomov 9584d50826 rbd: remove extra newlines from rbd_warn() messages
rbd_warn() string should be a single line - rbd_warn() appends \n.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-08-07 16:01:09 +04:00
Ilya Dryomov 7a716aac01 rbd: allocate img_request with GFP_NOIO instead GFP_ATOMIC
Now that rbd_img_request_create() is called from work functions, no
need to use GFP_ATOMIC.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-08-07 16:00:52 +04:00
Ilya Dryomov bc1ecc65a2 rbd: rework rbd_request_fn()
While it was never a good idea to sleep in request_fn(), commit
34c6bc2c91 ("locking/mutexes: Add extra reschedule point") made it
a *bad* idea.  mutex_lock() since 3.15 may reschedule *before* putting
task on the mutex wait queue, which for tasks in !TASK_RUNNING state
means block forever.  request_fn() may be called with !TASK_RUNNING on
the way to schedule() in io_schedule().

Offload request handling to a workqueue, one per rbd device, to avoid
calling blocking primitives from rbd_request_fn().

Fixes: http://tracker.ceph.com/issues/8818

Cc: stable@vger.kernel.org # 3.16, needs backporting for 3.15
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Tested-by: Eric Eastman <eric0e@aol.com>
Tested-by: Greg Wilson <greg.wilson@keepertech.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-08-07 14:56:20 +04:00
Ilya Dryomov 4d9b67cddd rbd: take snap_id into account when reading in parent info
If we are mapping a snapshot, we must read in the parent_overlap value
of that snapshot instead of that of the base image.  Not doing so may
in particular result in us returning zeros instead of user data:

    # cat overlap-snap.sh
    #!/bin/bash
    rbd create --size 10 --image-format 2 foo
    FOO_DEV=$(rbd map foo)
    dd if=/dev/urandom of=$FOO_DEV bs=1M &>/dev/null
    echo "Base image"
    dd if=$FOO_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd
    rbd snap create foo@snap
    rbd snap protect foo@snap
    rbd clone foo@snap bar
    rbd snap create bar@snap
    BAR_DEV=$(rbd map bar@snap)
    echo "Snapshot"
    dd if=$BAR_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd
    rbd resize --allow-shrink --size 4 bar
    echo "Snapshot after base image resize"
    dd if=$BAR_DEV bs=1 count=16 skip=$(((4 << 20) - 8)) 2>/dev/null | xxd

    # ./overlap-snap.sh
    Base image
    0000000: e781 e33b d34b 2225 6034 2845 a2e3 36ed  ...;.K"%`4(E..6.
    Snapshot
    0000000: e781 e33b d34b 2225 6034 2845 a2e3 36ed  ...;.K"%`4(E..6.
    Resizing image: 100% complete...done.
    Snapshot after base image resize
    0000000: e781 e33b d34b 2225 0000 0000 0000 0000  ...;.K"%........

Even though bar@snap is taken with the old bar parent_overlap (8M),
reads from bar@snap beyond the new bar parent_overlap (4M) return
zeroes.  Fix it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:16:50 +04:00
Ilya Dryomov e8f59b595d rbd: do not read in parent info before snap context
Currently rbd_dev_v2_header_info() reads in parent info before the snap
context is read in.  This is wrong, because we may need to look at the
the parent_overlap value of the snapshot instead of that of the base
image, for example when mapping a snapshot - see next commit.  (When
mapping a snapshot, all we got is its name and we need the snap context
to translate that name into an id to know which parent info to look
for.)

The approach taken here is to make sure rbd_dev_v2_parent_info() is
called after the snap context has been read in.  The other approach
would be to add a parent_overlap field to struct rbd_mapping and
maintain it the same way rbd_mapping::size is maintained.  The reason
I chose the first approach is that the value of keeping around both
base image values and the actual mapping values is unclear to me.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:16:14 +04:00
Ilya Dryomov 5ff1108ccc rbd: update mapping size only on refresh
There is no sense in trying to update the mapping size before it's even
been set.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:58 +04:00
Ilya Dryomov 52bb1f9bed rbd: harden rbd_dev_refresh() and callers a bit
Recently discovered watch/notify problems showed that we really can't
ignore errors in anything refresh related.  Alas, currently there is
not much we can do in response to those errors, except print warnings.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:44 +04:00
Ilya Dryomov 0407759971 rbd: split rbd_dev_spec_update() into two functions
rbd_dev_spec_update() has two modes of operation, with nothing in
common between them.  Split it into two functions, one for each mode
and make our expectations more clear.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:35 +04:00
Ilya Dryomov 7626eb7d82 rbd: remove unnecessary asserts in rbd_dev_image_probe()
spec->image_id assert doesn't buy us much and image_format is asserted
in rbd_dev_header_name() and rbd_dev_header_info() anyway.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:18 +04:00
Ilya Dryomov a720ae0901 rbd: introduce rbd_dev_header_info()
A wrapper around rbd_dev_v{1,2}_header_info() to reduce duplication.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:15:00 +04:00
Ilya Dryomov ff96128fb0 rbd: show the entire chain of parent images
Make /sys/bus/rbd/devices/<id>/parent show the entire chain of parent
images.  While at it, kernel sprintf() doesn't return negative values,
casting to unsigned long long is no longer necessary and there is no
good reason to split into multiple sprintf() calls.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-25 13:14:27 +04:00
Himangi Saraogi 7d5079aa8b rbd: use rbd_segment_name_free() instead of kfree()
Free memory allocated using kmem_cache_zalloc using kmem_cache_free
rather than kfree. The helper rbd_segment_name_free does the job here.
Its position is shifted above the calling function.

The Coccinelle semantic patch that detects this change is as follows:

// <smpl>
@@
expression x,E,c;
@@

 x = \(kmem_cache_alloc\|kmem_cache_zalloc\|kmem_cache_alloc_node\)(c,...)
 ... when != x = E
     when != &x
?-kfree(x)
+kmem_cache_free(c,x)
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-07-24 11:57:27 +04:00
Ilya Dryomov fbba11b3be rbd: do not leak image_id in rbd_dev_v2_parent_info()
image_id is leaked if the parent happens to have been recorded already.
Fix it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-08 15:08:46 +04:00
Ilya Dryomov 76756a51e2 rbd: use rbd_obj_watch_request_helper() helper
Switch rbd_dev_header_{un,}watch_sync() to use the new helper and fix
rbd_dev_header_unwatch_sync() to destroy watch_request structures
before queuing watch-remove message while at it.  This mistake slipped
into commit b30a01f2a3 ("rbd: fix osd_request memory leak in
__rbd_dev_header_watch_sync()") and could lead to "image still in use"
errors on image removal.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-08 15:08:45 +04:00
Ilya Dryomov bb040aa03c rbd: add rbd_obj_watch_request_helper() helper
In the past, rbd_dev_header_watch_sync() used to handle both watch and
unwatch requests and was entangled and leaky.  Commit b30a01f2a3
("rbd: fix osd_request memory leak in __rbd_dev_header_watch_sync()")
split it into two separate functions.  This commit cleanly abstracts
the common bits, relying on the fixed rbd_obj_request_wait().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-08 15:08:45 +04:00
Ilya Dryomov 71c20a066f rbd: rbd_obj_request_wait() should cancel the request if interrupted
rbd_obj_request_wait() should cancel the underlying OSD request if
interrupted.  Otherwise libceph will hold onto it indefinitely, causing
assert failures or leaking the original object request.

This also adds an rbd wrapper around ceph_osdc_cancel_request() to
match rbd_obj_request_submit() and rbd_obj_request_wait().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-07-08 15:08:45 +04:00
Ilya Dryomov 9638556a27 rbd: handle parent_overlap on writes correctly
The following check in rbd_img_obj_request_submit()

    rbd_dev->parent_overlap <= obj_request->img_offset

allows the fall through to the non-layered write case even if both
parent_overlap and obj_request->img_offset belong to the same RADOS
object.  This leads to data corruption, because the area to the left of
parent_overlap ends up unconditionally zero-filled instead of being
populated with parent data.  Suppose we want to write 1M to offset 6M
of image bar, which is a clone of foo@snap; object_size is 4M,
parent_overlap is 5M:

    rbd_data.<id>.0000000000000001
     ---------------------|----------------------|------------
    | should be copyup'ed | should be zeroed out | write ...
     ---------------------|----------------------|------------
   4M                    5M                     6M
                    parent_overlap    obj_request->img_offset

4..5M should be copyup'ed from foo, yet it is zero-filled, just like
5..6M is.

Given that the only striping mode kernel client currently supports is
chunking (i.e. stripe_unit == object_size, stripe_count == 1), round
parent_overlap up to the next object boundary for the purposes of the
overlap check.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-06-23 12:55:37 +04:00
Josh Durgin 22001f619f rbd: only set disk to read-only once
rbd_open(), called every time the device is opened, calls
set_device_ro().  There's no reason to set the device read-only or
read-write every time it is opened. Just do this once during device
setup, using set_disk_ro() instead because the struct block_device
isn't available to us there.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-06-10 18:09:25 -07:00
Josh Durgin 77f33c0373 rbd: move calls that may sleep out of spin lock range
get_user() and set_disk_ro() may allocate memory, leading to a
potential deadlock if theye are called while a spin lock is held.

Move the acquisition and release of rbd_dev->lock from rbd_ioctl()
into rbd_ioctl_set_ro(), so it can occur between get_user() and
set_disk_ro().

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-06-10 18:09:25 -07:00
Guangliang Zhao 131fd9f6fc rbd: add ioctl for rbd
When running the following commands:
    [root@ceph0 mnt]# blockdev --setro /dev/rbd1
    [root@ceph0 mnt]# blockdev --getro /dev/rbd1
    0

The block setro didn't take effect, it is because
the rbd doesn't support ioctl of block driver.

This resolves:
	http://tracker.ceph.com/issues/6265

Signed-off-by: Guangliang Zhao <guangliang@unitedstack.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-06-10 18:09:24 -07:00
Ilya Dryomov ffe312cf31 rbd: fix ida/idr memory leak
ida_destroy() needs to be called on module exit to release ida caches.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-06-06 09:30:00 +08:00
Alex Elder 0f2d5be792 rbd: use reference counts for image requests
Each image request contains a reference count, but to date it has
not actually been used.  (I think this was just an oversight.) A
recent report involving rbd failing an assertion shed light on why
and where we need to use these reference counts.

Every OSD request associated with an object request uses
rbd_osd_req_callback() as its callback function.  That function will
call a helper function (dependent on the type of OSD request) that
will set the object request's "done" flag if the object request if
appropriate.  If that "done" flag is set, the object request is
passed to rbd_obj_request_complete().

In rbd_obj_request_complete(), requests are processed in sequential
order.  So if an object request completes before one of its
predecessors in the image request, the completion is deferred.
Otherwise, if it's a completing object's "turn" to be completed, it
is passed to rbd_img_obj_end_request(), which records the result of
the operation, accumulates transferred bytes, and so on.  Next, the
successor to this request is checked and if it is marked "done",
(deferred) completion processing is performed on that request, and
so on.  If the last object request in an image request is completed,
rbd_img_request_complete() is called, which (typically) destroys
the image request.

There is a race here, however.  The instant an object request is
marked "done" it can be provided (by a thread handling completion of
one of its predecessor operations) to rbd_img_obj_end_request(),
which (for the last request) can then lead to the image request
getting torn down.  And this can happen *before* that object has
itself entered rbd_img_obj_end_request().  As a result, once it
*does* enter that function, the image request (and even the object
request itself) may have been freed and become invalid.

All that's necessary to avoid this is to properly count references
to the image requests.  We tear down an image request's object
requests all at once--only when the entire image request has
completed.  So there's no need for an image request to count
references for its object requests.  However, we don't want an
image request to go away until the last of its object requests
has passed through rbd_img_obj_callback().  In other words,
we don't want rbd_img_request_complete() to necessarily
result in the image request being destroyed, because it may
get called before we've finished processing on all of its
object requests.

So the fix is to add a reference to an image request for
each of its object requests.  The reference can be viewed
as representing an object request that has not yet finished
its call to rbd_img_obj_callback().  That is emphasized by
getting the reference right after assigning that as the image
object's callback function.  The corresponding release of that
reference is done at the end of rbd_img_obj_callback(), which
every image object request passes through exactly once.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-06-06 09:29:59 +08:00
Ilya Dryomov b30a01f2a3 rbd: fix osd_request memory leak in __rbd_dev_header_watch_sync()
osd_request, along with r_request and r_reply messages attached to it
are leaked in __rbd_dev_header_watch_sync() if the requested image
doesn't exist.  This is because lingering requests are special and get
an extra ref in the reply path.  Fix it by unregistering linger request
on the error path and split __rbd_dev_header_watch_sync() into two
functions to make it maintainable.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-06-06 09:29:59 +08:00
Ilya Dryomov 30ba1f0202 rbd: make sure we have latest osdmap on 'rbd map'
Given an existing idle mapping (img1), mapping an image (img2) in
a newly created pool (pool2) fails:

    $ ceph osd pool create pool1 8 8
    $ rbd create --size 1000 pool1/img1
    $ sudo rbd map pool1/img1
    $ ceph osd pool create pool2 8 8
    $ rbd create --size 1000 pool2/img2
    $ sudo rbd map pool2/img2
    rbd: sysfs write failed
    rbd: map failed: (2) No such file or directory

This is because client instances are shared by default and we don't
request an osdmap update when bumping a ref on an existing client.  The
fix is to use the mon_get_version request to see if the osdmap we have
is the latest, and block until the requested update is received if it's
not.

Fixes: http://tracker.ceph.com/issues/8184

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-06-06 09:29:58 +08:00
Duan Jiong 461f758ac0 rbd: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
This patch fixes coccinelle error regarding usage of IS_ERR and
PTR_ERR instead of PTR_ERR_OR_ZERO.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-06-06 09:29:51 +08:00
Ilya Dryomov 0ccd592669 rbd: prefix rbd writes with CEPH_OSD_OP_SETALLOCHINT osd op
In an effort to reduce fragmentation, prefix every rbd write with
a CEPH_OSD_OP_SETALLOCHINT osd op with an expected_write_size value set
to the object size (1 << order).  Backwards compatibility is taken care
of on the libceph/osd side.

"The CEPH_OSD_OP_SETALLOCHINT hint is durable, in that it's enough to
do it once.  The reason every rbd write is prefixed is that rbd doesn't
explicitly create objects and relies on writes creating them
implicitly, so there is no place to stick a single hint op into.  To
get around that we decided to prefix every rbd write with a hint (just
like write and setattr ops, hint op will create an object implicitly if
it doesn't exist)."

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov deb236b300 rbd: num_ops parameter for rbd_osd_req_create()
In preparation for prefixing rbd writes with an allocation hint
introduce a num_ops parameter for rbd_osd_req_create().  The rationale
is that not every write request is a write op that needs to be prefixed
(e.g. watch op), so the num_ops logic needs to be in the callers.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov 7cc69d42e6 libceph: bump CEPH_OSD_MAX_OP to 3
Our longest osd request now contains 3 ops: copyup+hint+write.

Also, CEPH_OSD_MAX_OP value in a BUG_ON in rbd_osd_req_callback() was
hard-coded to 2.  Fix it, and switch to rbd_assert while at it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov 42dd037c08 rbd: fix error paths in rbd_img_request_fill()
Doing rbd_obj_request_put() in rbd_img_request_fill() error paths is
not only insufficient, but also triggers an rbd_assert() in
rbd_obj_request_destroy():

    Assertion failure in rbd_obj_request_destroy() at line 1867:

    rbd_assert(obj_request->img_request == NULL);

rbd_img_obj_request_add() adds obj_requests to the img_request, the
opposite is rbd_img_obj_request_del().  Use it.

Fixes: http://tracker.ceph.com/issues/7327

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:51 +08:00
Ilya Dryomov 62054da65c rbd: remove out_partial label in rbd_img_request_fill()
Commit 03507db631 ("rbd: fix buffer size for writes to images with
snapshots") moved the call to rbd_img_obj_request_add() up, making the
out_partial label bogus.  Remove it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:50 +08:00
Alex Elder 638c323c4d rbd: drop an unsafe assertion
Olivier Bonvalet reported having repeated crashes due to a failed
assertion he was hitting in rbd_img_obj_callback():

    Assertion failure in rbd_img_obj_callback() at line 2165:
	rbd_assert(which >= img_request->next_completion);

With a lot of help from Olivier with reproducing the problem
we were able to determine the object and image requests had
already been completed (and often freed) at the point the
assertion failed.

There was a great deal of discussion on the ceph-devel mailing list
about this.  The problem only arose when there were two (or more)
object requests in an image request, and the problem was always
seen when the second request was being completed.

The problem is due to a race in the window between setting the
"done" flag on an object request and checking the image request's
next completion value.  When the first object request completes, it
checks to see if its successor request is marked "done", and if
so, that request is also completed.  In the process, the image
request's next_completion value is updated to reflect that both
the first and second requests are completed.  By the time the
second request is able to check the next_completion value, it
has been set to a value *greater* than its own "which" value,
which caused an assertion to fail.

Fix this problem by skipping over any completion processing
unless the completing object request is the next one expected.
Test only for inequality (not >=), and eliminate the bad
assertion.

Tested-by: Olivier Bonvalet <ob@daevel.fr>
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-03-29 10:38:14 -07:00
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
Ilya Dryomov 3c972c95c6 libceph: rename ceph_osd_request::r_{oloc,oid} to r_base_{oloc,oid}
Rename ceph_osd_request::r_{oloc,oid} to r_base_{oloc,oid} before
introducing r_target_{oloc,oid} needed for redirects.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-01-27 23:57:49 +02:00
Ilya Dryomov 4295f2217a libceph: introduce and start using oid abstraction
In preparation for tiering support, which would require having two
(base and target) object names for each osd request and also copying
those names around, introduce struct ceph_object_id (oid) and a couple
helpers to facilitate those copies and encapsulate the fact that object
name is not necessarily a NUL-terminated string.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-01-27 23:57:28 +02:00
Ilya Dryomov 2d0ebc5d59 libceph: rename MAX_OBJ_NAME_SIZE to CEPH_MAX_OID_NAME_LEN
In preparation for adding oid abstraction, rename MAX_OBJ_NAME_SIZE to
CEPH_MAX_OID_NAME_LEN.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-01-27 23:57:24 +02:00
Ilya Dryomov 22116525ba libceph: start using oloc abstraction
Instead of relying on pool fields in ceph_file_layout (for mapping) and
ceph_pg (for enconding), start using ceph_object_locator (oloc)
abstraction.  Note that userspace oloc currently consists of pool, key,
nspace and hash fields, while this one contains only a pool.  This is
OK, because at this point we only send (i.e. encode) olocs and never
have to receive (i.e. decode) them.

This makes keeping a copy of ceph_file_layout in every osd request
unnecessary, so ceph_osd_request::r_file_layout field is nuked.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-01-27 23:57:03 +02:00
Ilya Dryomov e37180c0f2 rbd: tear down watch request if rbd_dev_device_setup() fails
Tear down watch request if rbd_dev_device_setup() fails.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:32:07 +02:00
Ilya Dryomov fca2706539 rbd: introduce rbd_dev_header_unwatch_sync() and switch to it
Rename rbd_dev_header_watch_sync() to __rbd_dev_header_watch_sync() and
introduce two helpers: rbd_dev_header_{,un}watch_sync() to make it more
clear what is going on.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:32:06 +02:00
Ilya Dryomov 7e513d4366 rbd: enable extended devt in single-major mode
If single-major device number allocation scheme is turned on, instead
of reserving 256 minors per device, which imposes a limit of 4096
images mapped at once, reserve 16 minors per device and enable extended
devt feature.  This results in a theoretical limit of 65536 images
mapped at once, and still allows to have more than 15 partititions:
partitions starting with 16th are mapped under major 259 (Block
Extended Major):

$ rbd showmapped
id pool image snap device
0  rbd  b5    -    /dev/rbd0    # no partitions
1  rbd  b2    -    /dev/rbd1    # 40 partitions
2  rbd  b3    -    /dev/rbd2    #  2 partitions

$ cat /proc/partitions
 251        0       1024 rbd0
 251       16       1024 rbd1
 251       17          0 rbd1p1
 251       18          0 rbd1p2
 ...
 251       30          0 rbd1p14
 251       31          0 rbd1p15
 259        0          0 rbd1p16
 259        1          0 rbd1p17
 ...
 259       23          0 rbd1p39
 259       24          0 rbd1p40
 251       32       1024 rbd2
 251       33          0 rbd2p1
 251       34          0 rbd2p2

(major 251 was assigned dynamically at module load time)

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:32:04 +02:00
Ilya Dryomov 9b60e70b3b rbd: add support for single-major device number allocation scheme
Currently each rbd device is allocated its own major number, which
leads to a hard limit of 230-250 images mapped at once.  This commit
adds support for a new single-major device number allocation scheme,
which is hidden behind a new single_major boolean module parameter and
is disabled by default for backwards compatibility reasons.  (Old
userspace cannot correctly unmap images mapped under single-major
scheme and would essentially just unmap a random image, if that.)

$ rbd showmapped
id pool image snap device
0  rbd  b100  -    /dev/rbd0
1  rbd  b101  -    /dev/rbd1
2  rbd  b102  -    /dev/rbd2
3  rbd  b103  -    /dev/rbd3

Old scheme (modprobe rbd):

$ ls -l /dev/rbd*
brw-rw---- 1 root disk 253, 0 Dec 10 12:24 /dev/rbd0
brw-rw---- 1 root disk 252, 0 Dec 10 12:28 /dev/rbd1
brw-rw---- 1 root disk 252, 1 Dec 10 12:28 /dev/rbd1p1
brw-rw---- 1 root disk 252, 2 Dec 10 12:28 /dev/rbd1p2
brw-rw---- 1 root disk 252, 3 Dec 10 12:28 /dev/rbd1p3
brw-rw---- 1 root disk 251, 0 Dec 10 12:28 /dev/rbd2
brw-rw---- 1 root disk 251, 1 Dec 10 12:28 /dev/rbd2p1
brw-rw---- 1 root disk 250, 0 Dec 10 12:24 /dev/rbd3

New scheme (modprobe rbd single_major=Y):

$ ls -l /dev/rbd*
brw-rw---- 1 root disk 253,   0 Dec 10 12:30 /dev/rbd0
brw-rw---- 1 root disk 253, 256 Dec 10 12:30 /dev/rbd1
brw-rw---- 1 root disk 253, 257 Dec 10 12:30 /dev/rbd1p1
brw-rw---- 1 root disk 253, 258 Dec 10 12:30 /dev/rbd1p2
brw-rw---- 1 root disk 253, 259 Dec 10 12:30 /dev/rbd1p3
brw-rw---- 1 root disk 253, 512 Dec 10 12:30 /dev/rbd2
brw-rw---- 1 root disk 253, 513 Dec 10 12:30 /dev/rbd2p1
brw-rw---- 1 root disk 253, 768 Dec 10 12:30 /dev/rbd3

(major 253 was assigned dynamically at module load time)

The new limit is 4096 images mapped at once, and it comes from the fact
that, as before, 256 minor numbers are reserved for each mapping.
(A follow-up commit changes the number of minors reserved and the way
we deal with partitions over that number.)

If single_major is set to true, two new sysfs interfaces show up:
/sys/bus/rbd/{add,remove}_single_major.  These are to be used instead
of /sys/bus/rbd/{add,remove}, which are disabled for backwards
compatibility reasons outlined above.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:59 +02:00
Ilya Dryomov 92c76dc036 rbd: wire up is_visible() sysfs callback for rbd bus
In preparation for single-major device number allocation scheme, wire
up attribute_group::is_visible() callback for rbd bus.  This allows us
to make the new single-major attributes conditional.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:58 +02:00
Ilya Dryomov dd82fff1e8 rbd: add 'minor' sysfs rbd device attribute
Introduce /sys/bus/rbd/devices/<id>/minor sysfs attribute for exporting
rbd whole disk minor numbers.  This is a step towards single-major
device number allocation scheme, but also a good thing on its own.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:57 +02:00
Ilya Dryomov f8a22fc238 rbd: switch to ida for rbd id assignments
Currently rbd ids are allocated using an atomic variable that keeps
track of the highest id currently in use and each new id is simply one
more than the value of that variable.  That's nice and cheap, but it
does mean that rbd ids are allowed to grow boundlessly, and, more
importantly, it's completely unpredictable.  So, in preparation for
single-major device number allocation scheme, which is going to
establish and rely on a constant mapping between rbd ids and device
numbers, switch to ida for rbd id assignments.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:56 +02:00
Ilya Dryomov e1b4d96dea rbd: refactor rbd_init() a bit
Refactor rbd_init() a bit to make it more clear what's going on.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:55 +02:00
Ilya Dryomov 90da258b88 rbd: tweak "loaded" message and module description
Tweak "loaded" message, so that it looks like

[   30.184235] rbd: loaded

instead of

[   38.056564] rbd: loaded rbd (rados block device)

Also move (and slightly tweak) MODULE_DESCRIPTION so that all authors
are next to each other in modinfo output.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:54 +02:00
Ilya Dryomov 70eebd2006 rbd: rbd_device::dev_id is an int, format it as such
rbd_device::dev_id is an int, format it as such.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-12-31 20:31:53 +02:00
Kent Overstreet 5341a6278b rbd: Refactor bio cloning
Now that we've got drivers converted to the new immutable bvec
primitives, bio splitting becomes much easier - this is how the new
bio_split() will work. (Someone more familiar with the ceph code could
probably use bio_clone_fast() instead of bio_clone() here).

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
2013-11-23 22:33:54 -08:00
Kent Overstreet 7988613b0e block: Convert bio_for_each_segment() to bvec_iter
More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.

This updates callers for the new usage without changing the
implementation yet.

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: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jim Paris <jim@jtan.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: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: support@lsi.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand <geoff@infradead.org>
2013-11-23 22:33:49 -08:00
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
Linus Torvalds e9ff04dd94 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull ceph fixes from Sage Weil:
 "These fix several bugs with RBD from 3.11 that didn't get tested in
  time for the merge window: some error handling, a use-after-free, and
  a sequencing issue when unmapping and image races with a notify
  operation.

  There is also a patch fixing a problem with the new ceph + fscache
  code that just went in"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  fscache: check consistency does not decrement refcount
  rbd: fix error handling from rbd_snap_name()
  rbd: ignore unmapped snapshots that no longer exist
  rbd: fix use-after free of rbd_dev->disk
  rbd: make rbd_obj_notify_ack() synchronous
  rbd: complete notifies before cleaning up osd_client and rbd_dev
  libceph: add function to ensure notifies are complete
2013-09-19 12:50:37 -05:00
Jingoo Han bb8e0e84b3 block: replace strict_strtoul() with kstrtoul()
The use 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:56:56 -07:00
Josh Durgin da6a6b6397 rbd: fix error handling from rbd_snap_name()
rbd_snap_name() calls rbd_dev_v{1,2}_snap_name() depending on the
format of the image. The format 1 version returns NULL on error, which
is handled by the caller. The format 2 version returns an ERR_PTR,
which the caller of rbd_snap_name() does not expect.

Fortunately this is unlikely to occur in practice because
rbd_snap_id_by_name() is called before rbd_snap_name(). This would hit
similar errors to rbd_snap_name() (like the snapshot not existing) and
return early, so rbd_snap_name() would not hit an error unless the
snapshot was removed between the two calls or memory was exhausted.

Use an ERR_PTR in rbd_dev_v1_snap_name() so that the specific error
can be propagated, and it is consistent with rbd_dev_v2_snap_name().
Handle the ERR_PTR in the only rbd_snap_name() caller.

Suggested-by: Alex Elder <alex.elder@linaro.org>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-09-09 11:16:44 -07:00
Josh Durgin efadc98aab rbd: ignore unmapped snapshots that no longer exist
This prevents erroring out while adding a device when a snapshot
unrelated to the current mapping is deleted between reading the
snapshot context and reading the snapshot names. If the mapped
snapshot name is not found an error still occurs as usual.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-09-09 11:16:32 -07:00
Josh Durgin 9875201e10 rbd: fix use-after free of rbd_dev->disk
Removing a device deallocates the disk, unschedules the watch, and
finally cleans up the rbd_dev structure. rbd_dev_refresh(), called
from the watch callback, updates the disk size and rbd_dev
structure. With no locking between them, rbd_dev_refresh() may use the
device or rbd_dev after they've been freed.

To fix this, check whether RBD_DEV_FLAG_REMOVING is set before
updating the disk size in rbd_dev_refresh(). In order to prevent a
race where rbd_dev_refresh() is already revalidating the disk when
rbd_remove() is called, move the call to rbd_bus_del_dev() after the
watch is unregistered and all notifies are complete. It's safe to
defer deleting this structure because no new requests can be submitted
once the RBD_DEV_FLAG_REMOVING is set, since the device cannot be
opened.

Fixes: http://tracker.ceph.com/issues/5636
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-09-09 11:16:25 -07:00
Josh Durgin 20e0af67ce rbd: make rbd_obj_notify_ack() synchronous
The only user of rbd_obj_notify_ack() is rbd_watch_cb(). It used
asynchronously with no tracking of when the notify ack completes, so
it may still be in progress when the osd_client is shut down.  This
results in a BUG() since the osd client assumes no requests are in
flight when it stops. Since all notifies are flushed before the
osd_client is stopped, waiting for the notify ack to complete before
returning from the watch callback ensures there are no notify acks in
flight during shutdown.

Rename rbd_obj_notify_ack() to rbd_obj_notify_ack_sync() to reflect
its new synchronous nature.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-09-09 11:16:02 -07:00
Josh Durgin 9abc59908e rbd: complete notifies before cleaning up osd_client and rbd_dev
To ensure rbd_dev is not used after it's released, flush all pending
notify callbacks before calling rbd_dev_image_release(). No new
notifies can be added to the queue at this point because the watch has
already be unregistered with the osd_client.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-09-09 11:15:57 -07:00
Linus Torvalds 6cccc7d301 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull ceph updates from Sage Weil:
 "This includes both the first pile of Ceph patches (which I sent to
  torvalds@vger, sigh) and a few new patches that add support for
  fscache for Ceph.  That includes a few fscache core fixes that David
  Howells asked go through the Ceph tree.  (Thanks go to Milosz Tanski
  for putting this feature together)

  This first batch of patches (included here) had (has) several
  important RBD bug fixes, hole punch support, several different
  cleanups in the page cache interactions, improvements in the truncate
  code (new truncate mutex to avoid shenanigans with i_mutex), and a
  series of fixes in the synchronous striping read/write code.

  On top of that is a random collection of small fixes all across the
  tree (error code checks and error path cleanup, obsolete wq flags,
  etc)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (43 commits)
  ceph: use d_invalidate() to invalidate aliases
  ceph: remove ceph_lookup_inode()
  ceph: trivial buildbot warnings fix
  ceph: Do not do invalidate if the filesystem is mounted nofsc
  ceph: page still marked private_2
  ceph: ceph_readpage_to_fscache didn't check if marked
  ceph: clean PgPrivate2 on returning from readpages
  ceph: use fscache as a local presisent cache
  fscache: Netfs function for cleanup post readpages
  FS-Cache: Fix heading in documentation
  CacheFiles: Implement interface to check cache consistency
  FS-Cache: Add interface to check consistency of a cached object
  rbd: fix null dereference in dout
  rbd: fix buffer size for writes to images with snapshots
  libceph: use pg_num_mask instead of pgp_num_mask for pg.seed calc
  rbd: fix I/O error propagation for reads
  ceph: use vfs __set_page_dirty_nobuffers interface instead of doing it inside filesystem
  ceph: allow sync_read/write return partial successed size of read/write.
  ceph: fix bugs about handling short-read for sync read mode.
  ceph: remove useless variable revoked_rdcache
  ...
2013-09-09 09:13:22 -07:00
Josh Durgin c35455791c rbd: fix null dereference in dout
The order parameter is sometimes NULL in _rbd_dev_v2_snap_size(), but
the dout() always derefences it. Move this to another dout() protected
by a check that order is non-NULL.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <alex.elder@linaro.org>
2013-09-03 22:08:51 -07:00
Josh Durgin 03507db631 rbd: fix buffer size for writes to images with snapshots
rbd_osd_req_create() needs to know the snapshot context size to create
a buffer large enough to send it with the message front. It gets this
from the img_request, which was not set for the obj_request yet. This
resulted in trying to write past the end of the front payload, hitting
this BUG:

libceph: BUG_ON(p > msg->front.iov_base + msg->front.iov_len);

Fix this by associating the obj_request with its img_request
immediately after it's created, before the osd request is created.

Fixes: http://tracker.ceph.com/issues/5760
Suggested-by: Alex Elder <alex.elder@linaro.org>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <alex.elder@linaro.org>
2013-09-03 22:08:46 -07:00
Josh Durgin 17c1cc1d92 rbd: fix I/O error propagation for reads
When a request returns an error, the driver needs to report the entire
extent of the request as completed.  Writes already did this, since
they always set xferred = length, but reads were skipping that step if
an error other than -ENOENT occurred.  Instead, rbd would end up
passing 0 xferred to blk_end_request(), which would always report
needing more data.  This resulted in an assert failing when more data
was required by the block layer, but all the object requests were
done:

[ 1868.719077] rbd: obj_request read result -108 xferred 0
[ 1868.719077]
[ 1868.719518] end_request: I/O error, dev rbd1, sector 0
[ 1868.719739]
[ 1868.719739] Assertion failure in rbd_img_obj_callback() at line 1736:
[ 1868.719739]
[ 1868.719739]   rbd_assert(more ^ (which == img_request->obj_request_count));

Without this assert, reads that hit errors would hang forever, since
the block layer considered them incomplete.

Fixes: http://tracker.ceph.com/issues/5647
CC: stable@vger.kernel.org  # v3.10
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <alex.elder@linaro.org>
2013-09-03 22:06:10 -07:00
Greg Kroah-Hartman b15a21ddda rbd: convert bus code to use bus_groups
The bus_attrs field of struct bus_type is going away soon, dev_groups
should be used instead.  This converts the RBD bus code to use the
correct field.

Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Acked-by: Alex Elder <elder@linaro.org>
Cc: <ceph-devel@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27 22:07:49 -07:00
Jingoo Han a158073c43 block: rbd: use NULL instead of 0
The local variables such as 'bio_list', and 'pages' are pointers;
thus, use NULL instead of 0 to fix the following sparse warnings.

drivers/block/rbd.c:2166:32: warning: Using plain integer as NULL pointer
drivers/block/rbd.c:2168:31: warning: Using plain integer as NULL pointer

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-08-09 17:55:40 -07:00
Sage Weil e976cad0f0 rbd: fix a couple warnings
gcc isn't quite smart enough and generates these warnings:

drivers/block/rbd.c: In function 'rbd_img_request_fill':
drivers/block/rbd.c:1266:22: warning: 'bio_list' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/block/rbd.c:2186:14: note: 'bio_list' was declared here
drivers/block/rbd.c:2247:10: warning: 'pages' may be used uninitialized in this function [-Wmaybe-uninitialized]

even though they are initialized for their respective code paths.

Signed-off-by: Sage Weil <sage@inktank.com>
2013-07-03 15:32:50 -07:00
Alex Elder d552c6191b rbd: take a little credit
Add a name to the list of authors.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:44 -07:00
Alex Elder cfbf6377b6 rbd: use rwsem to protect header updates
Updating an image header needs to be protected to ensure it's
done consistently.  However distinct headers can be updated
concurrently without a problem.  Instead of using the global
control lock to serialize headder updates, just rely on the header
semaphore.  (It's already used, this just moves it out to cover
a broader section of the code.)

That leaves the control mutex protecting only the creation of rbd
clients, so rename it.

This resolves:
    http://tracker.ceph.com/issues/5222

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:43 -07:00
Alex Elder 1ba0f1e797 rbd: don't hold ctl_mutex to get/put device
When an rbd device is first getting mapped, its device registration
is protected the control mutex.  There is no need to do that though,
because the device has already been assigned an id that's guaranteed
to be unique.

An unmap of an rbd device won't proceed if the device has a non-zero
open count or is already being unmapped.  So there's no need to hold
the control mutex in that case either.

Finally, an rbd device can't be opened if it is being removed, and
it won't go away if there is a non-zero open count.  So here too
there's no need to hold the control mutex while getting or putting a
reference to an rbd device's Linux device structure.

Drop the mutex calls in these cases.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:42 -07:00
Alex Elder 82a442d239 rbd: protect against concurrent unmaps
Make sure two concurrent unmap operations on the same rbd device
won't collide, by only proceeding with the removal and cleanup of a
device if is not already underway.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:41 -07:00
Alex Elder 751cc0e3cf rbd: set removing flag while holding list lock
When unmapping a device, its id is supplied, and that is used to
look up which rbd device should be unmapped.  Looking up the
device involves searching the rbd device list while holding
a spinlock that protects access to that list.

Currently all of this is done under protection of the control lock,
but that protection is going away soon.  To ensure the rbd_dev is
still valid (still on the list) while setting its REMOVING flag, do
so while still holding the list lock.  To do so, get rid of
__rbd_get_dev(), and open code what it did in the one place it
was used.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:41 -07:00
Alex Elder 08f75463c1 rbd: protect against duplicate client creation
If more than one rbd image has the same ceph cluster configuration
(same options, same set of monitors, same keys) they normally share
a single rbd client.

When an image is getting mapped, rbd looks to see if an existing
client can be used, and creates a new one if not.

The lookup and creation are not done under a common lock though, so
mapping two images concurrently could lead to duplicate clients
getting set up needlessly.  This isn't a major problem, but it's
wasteful and different from what's intended.

This patch fixes that by using the control mutex to protect
both the lookup and (if needed) creation of the client.  It
was previously used just when creating.

This resolves:
    http://tracker.ceph.com/issues/3094

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:39 -07:00
Alex Elder 3b5cf2a2f1 rbd: clean up a few things in the refresh path
This includes a few relatively small fixes I found while examining
the code that refreshes image information.

This resolves:
    http://tracker.ceph.com/issues/5040

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:38 -07:00
Alex Elder e215605417 rbd: flush dcache after zeroing page data
Neither zero_bio_chain() nor zero_pages() contains a call to flush
caches after zeroing a portion of a page.  This can cause problems
on architectures that have caches that allow virtual address
aliasing.

This resolves:
    http://tracker.ceph.com/issues/4777

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-03 15:32:37 -07:00
Alex Elder 912c317d46 rbd: drop original request earlier for existence check
The reference to the original request dropped at the end of
rbd_img_obj_exists_callback() corresponds to the reference taken
in rbd_img_obj_exists_submit() to account for the stat request
referring to it.  Move the put of that reference up right after
clearing that pointer to make its purpose more obvious.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-07-01 09:52:02 -07:00
Geert Uytterhoeven 491205a8b4 rbd: Use min_t() to fix comparison of distinct pointer types warning
drivers/block/rbd.c: In function ‘zero_pages’:
drivers/block/rbd.c:1102: warning: comparison of distinct pointer types lacks a cast

Remove the hackish casts and use min_t() to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-07-01 09:52:01 -07:00
Linus Torvalds bd2931b5cf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fix from Sage Weil:
 "This is a recently spotted regression in the snapshot behavior...

  It turns out several tests weren't being run in the nightlies so this
  took a while to spot"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: send snapshot context with writes
2013-06-29 10:31:15 -07:00
Josh Durgin d2d1f17a0d rbd: send snapshot context with writes
Sending the right snapshot context with each write is required for
snapshots to work. Due to the ordering of calls, the snapshot context
is never set for any requests. This causes writes to the current
version of the image to be reflected in all snapshots, which are
supposed to be read-only.

This happens because rbd_osd_req_format_write() sets the snapshot
context based on obj_request->img_request. At this point, however,
obj_request->img_request has not been set yet, to the snapshot context
is set to NULL. Fix this by moving rbd_img_obj_request_add(), which
sets obj_request->img_request, before the osd request formatting
calls.

This resolves:
    http://tracker.ceph.com/issues/5465

Reported-by: Karol Jurak <karol.jurak@gmail.com>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2013-06-27 05:55:29 -07:00
Linus Torvalds 78750f1908 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fix from Sage Weil:
 "This fixes another problem with using v2 images on 3.10 due to the
  order in which fields are read from the image header.

  Hopefully this is the last one"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fetch object order before using it
2013-06-26 08:47:46 -10:00
Josh Durgin 1617e40c1e rbd: fetch object order before using it
rbd_dev_v2_header_onetime() fetches striping information, and
checks whether the image can be read by compariing the stripe unit
to the object size. It determines the object size by shifting
the object order, which is 0 at this point since it has not been
read yet. Move the call to get the image size and object order
before rbd_dev_v2_header_onetime() so it is set before use.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-06-25 12:27:31 -07:00
Linus Torvalds 7ecba6f2f3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fix from Sage Weil:
 "This fixes a problem preventing the kernel and userland librbd
  libraries from sharing data with the new format 2 images"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: use the correct length for format 2 object names
2013-06-21 06:27:40 -10:00
Josh Durgin 3a96d5cd7b rbd: use the correct length for format 2 object names
Format 2 objects use 16 characters for the object name suffix to be
able to express the full 64-bit range of object numbers. Format 1
images only use 12 characters for this. Using 12-character names for
format 2 caused userspace and kernel rbd clients to read differently
named objects, which made an image written by one client look empty to
the other client.

CC: stable@vger.kernel.org  # 3.9+
Reported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-06-13 08:46:15 -07:00
Linus Torvalds 8d7a8fe2ce Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull ceph fixes from Sage Weil:
 "There is a pair of fixes for double-frees in the recent bundle for
  3.10, a couple of fixes for long-standing bugs (sleep while atomic and
  an endianness fix), and a locking fix that can be triggered when osds
  are going down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix cleanup in rbd_add()
  rbd: don't destroy ceph_opts in rbd_add()
  ceph: ceph_pagelist_append might sleep while atomic
  ceph: add cpu_to_le32() calls when encoding a reconnect capability
  libceph: must hold mutex for reset_changed_osds()
2013-06-12 08:28:19 -07:00
Alex Elder 3abef3b358 rbd: fix cleanup in rbd_add()
Bjorn Helgaas pointed out that a recent commit introduced a
use-after-free condition in an error path for rbd_add().
He correctly stated:

    I think b536f69a3a "rbd: set up devices only for mapped images"
    introduced a use-after-free error in rbd_add():
	...
    If rbd_dev_device_setup() returns an error, we call
    rbd_dev_image_release(), which ultimately kfrees rbd_dev.
    Then we call rbd_dev_destroy(), which references fields in
    the already-freed rbd_dev struct before kfreeing it again.

The simple fix is to return the error code after the call to
rbd_dev_image_release().

Closer examination revealed that there's no need to clean up
rbd_opts in that function, so fix that too.

Update some other comments that have also become out of date.

Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-17 12:50:10 -05:00
Alex Elder 7262cfca43 rbd: don't destroy ceph_opts in rbd_add()
Whether rbd_client_create() successfully creates a new client or
not, it takes responsibility for getting the ceph_opts structure
it's passed destroyed.  If successful, the structure becomes
associated with the created client; if not, rbd_client_create()
will destroy it.

Previously, rbd_get_client() would call ceph_destroy_options()
if rbd_get_client() failed, and that meant it got called twice.
That led freeing various pointers more than once, which is never a
good idea.

This resolves:
    http://tracker.ceph.com/issues/4559

Cc: stable@vger.kernel.org # 3.8+
Reported-by: Dan van der Ster <dan@vanderster.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-17 12:50:03 -05:00
Linus Torvalds 109c3c0292 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fixes from Sage Weil:
 "Yes, this is a much larger pull than I would like after -rc1.  There
  are a few things included:

   - a few fixes for leaks and incorrect assertions
   - a few patches fixing behavior when mapped images are resized
   - handling for cloned/layered images that are flattened out from
     underneath the client

  The last bit was non-trivial, and there is some code movement and
  associated cleanup mixed in.  This was ready and was meant to go in
  last week but I missed the boat on Friday.  My only excuse is that I
  was waiting for an all clear from the testing and there were many
  other shiny things to distract me.

  Strictly speaking, handling the flatten case isn't a regression and
  could wait, so if you like we can try to pull the series apart, but
  Alex and I would much prefer to have it all in as it is a case real
  users will hit with 3.10."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (33 commits)
  rbd: re-submit flattened write request (part 2)
  rbd: re-submit write request for flattened clone
  rbd: re-submit read request for flattened clone
  rbd: detect when clone image is flattened
  rbd: reference count parent requests
  rbd: define parent image request routines
  rbd: define rbd_dev_unparent()
  rbd: don't release write request until necessary
  rbd: get parent info on refresh
  rbd: ignore zero-overlap parent
  rbd: support reading parent page data for writes
  rbd: fix parent request size assumption
  libceph: init sent and completed when starting
  rbd: kill rbd_img_request_get()
  rbd: only set up watch for mapped images
  rbd: set mapping read-only flag in rbd_add()
  rbd: support reading parent page data
  rbd: fix an incorrect assertion condition
  rbd: define rbd_dev_v2_header_info()
  rbd: get rid of trivial v1 header wrappers
  ...
2013-05-15 13:36:19 -07:00
Alex Elder 638f5abed3 rbd: re-submit flattened write request (part 2)
Add code to rbd_img_obj_exists_callback() to detect when a clone's
parent image has disappeared, and re-submit the original write
request in that case.

Kill off some redundant assertions.

This completes the resolution for:
    http://tracker.ceph.com/issues/3763

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:46 -05:00
Alex Elder bbea1c1a31 rbd: re-submit write request for flattened clone
Add code to rbd_img_parent_read_full_callback() to detect when a
clone's parent image has disappeared, and re-submit the original
write request in that case.  (See the previous commit for more
reasoning about why this is appropriate.)

Rename some variables in rbd_img_obj_parent_read_full_callback()
to match the convention used in the previous patch.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:45 -05:00
Alex Elder 02c74fbad9 rbd: re-submit read request for flattened clone
If a clone image gets flattened while a parent read request is
underway, the original rbd object request needs to be resubmitted.

The reason is that by the time we get the response to the parent
read request, the data read from the parent may be out of date.
In other words, we could see this sequence of events:

    rbd client                      parent image/osd
    ----------                      ----------------
    original object ENOENT;
        issue parent read
                                    respond to parent read
                                    child image flattened
    original image header refresh
             <--- original object written independently here
    parent read response received

Add code to rbd_img_parent_read_callback() to detect when a clone's
parent image has disappeared (as evidenced by its parent overlap
becoming 0), and re-submit the original read request in that case.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:45 -05:00
Alex Elder 392a9dad7e rbd: detect when clone image is flattened
A format 2 clone image can be the subject of a "flatten" operation,
during which all of its data gets "copied up" from its parent image,
leaving the image fully populated.  Once this is complete, the
clone's association with the parent is abolished.

Since this can occur when a clone is mapped, we need to detect when
it has occurred and handle it accordingly.  We know an image has
been flattened when we know it at one time had a parent, but we have
learned (via a "get_parent" object class method call) it no longer
has one.

There might be in-flight requests at the point we learn an image has
been flattened, so we can't simply clean up parent data structures
right away.  Instead, we'll drop the initial parent reference when
the parent has disappeared (rather than when the image gets
destroyed), which will allow the last in-flight reference to clean
things up when it's complete.

We leverage the fact that a zero parent overlap renders an image
effectively unlayered.  We set the overlap to 0 at the point we
detect the clone image has flattened, which allows the unlayered
behavior to take effect immediately, while keeping other parent
structures in place until in-flight requests to complete.

This and the next few patches resolve:
    http://tracker.ceph.com/issues/3763

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:45 -05:00
Alex Elder a2acd00e79 rbd: reference count parent requests
Keep a reference count for uses of the parent information for an rbd
device.

An initial reference is set in rbd_img_request_create() if the
target image has a parent (with non-zero overlap).  Each image
request for an image with a non-zero parent overlap gets another
reference when it's created, and that reference is dropped when the
request is destroyed.

The initial reference is dropped when the image gets torn down.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:44 -05:00
Alex Elder e93f315235 rbd: define parent image request routines
Define rbd_parent_request_create() and rbd_parent_request_destroy()
to handle the creation of parent image requests submitted for
layered image objects.  For simplicity, let rbd_img_request_put()
handle dropping the reference to any image request (parent or not),
and call whichever destructor is appropriate on the last put.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:44 -05:00
Alex Elder fb65d2284c rbd: define rbd_dev_unparent()
Define rbd_dev_unparent() to encapsulate cleaning up parent data
structures from a layered rbd image.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:43 -05:00
Alex Elder 8785b1d487 rbd: don't release write request until necessary
Previously when a layered write was going to involve a copyup
request, the original osd request was released before submitting the
parent full-object read.  The osd request for the copyup would then
be allocated in rbd_img_obj_parent_read_full_callback().

Shortly we will be handling the event of mapped layered images
getting flattened, and when that occurs we need to resubmit the
original request.  We therefore don't want to release the osd
request until we really konw we're going to replace it--in the
callback function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:43 -05:00
Alex Elder 642a25375f rbd: get parent info on refresh
Get parent info for format 2 images on every refresh (rather than
just during the initial probe).  This will be needed to detect the
disappearance of the parent image in the event a mapped image
becomes unlayered (i.e., flattened).  Avoid leaking the previous
parent spec on the second and subsequent times this information is
requested by dropping the previous one (if any) before updating it.
(Also, extract the pool id into a local variable before assigning
it into the parent spec.)

Switch to using a non-zero parent overlap value rather than the
existence of a parent (a non-null parent_spec pointer) to determine
whether to mark a request layered.  It will soon be possible for
a layered image to become unlayered while a request is in flight.

This means that the layered flag for an image request indicates that
there was a non-zero parent overlap at the time the image request
was created.  The parent overlap can change thereafter, which may
lead to special handling at request submission or completion time.

This and the next several patches are related to:
    http://tracker.ceph.com/issues/3763

NOTE:
If an error occurs while refreshing the parent info (i.e.,
requesting it after initial probe), the old parent info will
persist.  This is not really correct, and is a scenario that needs
to be addressed.  For now we'll assert that the failure mode is
unlikely, but the issue has been documented in tracker issue 5040.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 15:06:33 -05:00
Alex Elder 70cf49cfc7 rbd: ignore zero-overlap parent
An rbd clone image that has an overlap with its parent of 0 is
effectively not a layered image at all.  Detect this case and treat
such an image as non-layered.  Issue a warning to be sure the user
knows what's going on.

This resolves:
    http://tracker.ceph.com/issues/5028

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 14:12:41 -05:00
Alex Elder b91f09f17b rbd: support reading parent page data for writes
Currently, rbd_img_obj_parent_read_full() assumes the incoming
object request contains bio data.  But if a layered image is part of
a multi-layer stack of images it will result in read requests of
page data to parent images.

This is handling the same kind of issue as was resolved by this
commit:
    5b2ab72d  rbd: support reading parent page data

This resolves:
    http://tracker.ceph.com/issues/5027

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 14:12:40 -05:00
Alex Elder ebda6408f2 rbd: fix parent request size assumption
The code that reads object data from the parent for a copyup on
write request currently assumes that the size of that request is the
size of a "full" object from the original target image.

That is not necessarily the case.  The parent overlap could reduce
the request size below that.  To fix that assumption we need to
record the number of pages in the copyup_pages array, for both an
image request and an object request.  Rename a local variable in
rbd_img_obj_parent_read_full_callback() to reflect we're recording
the length of the parent read request, not the size of the target
object.

This resolves:
    http://tracker.ceph.com/issues/5038

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-13 14:09:01 -05:00
Alex Elder c48f3f86e2 rbd: kill rbd_img_request_get()
Get rid of rbd_img_request_get(), because it isn't used, and maybe
won't ever be needed.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 20:17:00 -05:00
Alex Elder 1f3ef78861 rbd: only set up watch for mapped images
Any changes to parent images are immaterial to any mapped clone.
So there is no need to have a watch event registered on header
objects except for the header object of an image that is mapped.
In fact, a watch request is a write operation, and we may only
have read access to a parent image.

We can't set up the watch request until we know the name of the
header object though.  So pass a flag to rbd_dev_image_probe() to
indicate whether this probe is for a mapping or for a parent image.

Change the second parameter to rbd_dev_header_watch_sync() be
Boolean while we're at it.

This resolves:
    http://tracker.ceph.com/issues/4941

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 20:16:55 -05:00
Alex Elder 7ce4eef7b5 rbd: set mapping read-only flag in rbd_add()
The rbd_dev->mapping field for a parent image is not meaningful.
Since rbd_image_probe() is used both for images being mapped and
their parents, it doesn't make sense to set that flag in that
function.

So move the setting of the mapping.read_only flag out of
rbd_dev_image_probe() and into rbd_add() instead.

This resolves:
    http://tracker.ceph.com/issues/4940

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 20:16:50 -05:00
Alex Elder 5b2ab72d36 rbd: support reading parent page data
Currently, rbd_img_parent_read() assumes the incoming object request
contains bio data.  But if a layered image is part of a multi-layer
stack of images it will result in read requests of page data to parent
images.

Fortunately, it's not hard to add support for page data.

This resolves:
    http://tracker.ceph.com/issues/4939

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 20:16:25 -05:00
Alex Elder 91c6febb38 rbd: fix an incorrect assertion condition
In rbd_img_obj_parent_read_full_callback() there is an assertion
intended to verify the size of the image request for a full parent
read was the size of the original request's target object.  But
assertion was looking at the parent image order rather than the
original one, and these values can differ.

Fix that.

This resolves:
    http://tracker.ceph.com/issues/4938

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 20:16:10 -05:00
Alex Elder 2df3fac758 rbd: define rbd_dev_v2_header_info()
This rearranges rbd_dev_v2_refresh() so it works more like
rbd_dev_v1_header_info().  While format 1 images need to read the
whole header object to get any information, format 2 can collect
almost all information selectively.  So the one-time initialization
will remain in a separate function--based on rbd_dev_v2_probe().

Rename rbd_dev_v2_refresh() to be rbd_dev_v2_header_info(), and have
it call rbd_dev_v2_header_onetime() if it's being called for the
first time for the given rbd device.

Rename rbd_dev_v2_probe() to be rbd_dev_v2_header_onetime() and
remove the image size and snapshot context calls it held in
common with the refresh function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:52 -05:00
Alex Elder 99a41ebcee rbd: get rid of trivial v1 header wrappers
Get rid of the trivial wrapper functions rbd_dev_v1_refresh() and
rbd_dev_v1_probe(), substituting rbd_dev_v1_header_read() calls
in their place.

Rename rbd_dev_v1_header_read() to be rbd_dev_v1_header_info(), to
be more generic (it will better reflect what happens with format 2
images).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:46 -05:00
Alex Elder 30d60ba2f2 rbd: simplify rbd_dev_v1_probe()
An rbd_dev structure's fields are all zero-filled for an initial
probe, so there's no need to explicitly zero the parent_spec
and parent_overlap fields in rbd_dev_v1_probe().  Removing these
assignments makes rbd_dev_v1_probe() *almost* trivial.

Move the dout() message that announces discovery of an image into
rbd_dev_image_probe(), generalize to support images in either format
and only show it if an image is fully discovered.

This highlights that are some unnecessary cleanups in the error
path for rbd_dev_v1_probe(), so they can be removed.

Now rbd_dev_v1_probe() *is* a trivial wrapper function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:41 -05:00
Alex Elder 662518b128 rbd: update in-core header directly
Now that rbd_header_from_disk() only fills in one-time fields once,
we can extend it slightly so it releases the other fields before
replacing their values.  This way there's no need to pass a
temporary buffer and then copy all the results in.  Just use the rbd
device header structure in rbd_header_from_disk() so its values get
updated directly.

Note that this means we need to take the header semaphore at the
point we update things.  So pass the rbd_dev rather than the address
of its header as its first argument to rbd_header_from_disk(), and
have it return an error code.

As a result, rbd_dev_v1_header_read() does all the work,
rbd_read_header() becomes unnecessary, and rbd_dev_v1_refresh()
becomes a very simple wrapper.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:37 -05:00
Alex Elder bb23e37acb rbd: refactor rbd_header_from_disk()
This rearranges rbd_header_from_disk so that it:
    - allocates the snapshot context right away
    - keeps results in local variables, not changing the passed-in
      header until it's known we'll succeed
    - does initialization of set-once fields in a header only if
      they have not already been set

The last point is moot at the moment, because rbd_read_header()
(the only caller) always supplies a zero-filled header buffer.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:33 -05:00
Alex Elder 46578dcdca rbd: zero format 1 header structure earlier
The passed-in header structure is zeroed in rbd_header_from_disk().
Instead, have the caller do it.  Note that there are two callers,
rbd_dev_v1_refresh() and rbd_dev_v1_probe().  The latter already has
a zeroed header structure so zeroing it isn't necessary there.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:28 -05:00
Alex Elder f35a4dee14 rbd: set the mapping size and features later
Defer setting the size and features fields of a mapped image until
after the Linux disk structure is set up.  Set the capacity of the
disk after that.

Rearrange the definition of rbd_image_header, separating the fields
that are set only once from those that can be updated.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 17:00:00 -05:00
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
Alex Elder 51344a38ba rbd: always set read-only flag in rbd_add()
Hold off setting the read-only flag in rbd_add() for an image being
mapped until we have successfully probed the image.  At that point
we know whether it's a snapshot mapping or not, so we can set the
read-only flag in that one place rather than doing so (for
snapshots) in rbd_dev_mapping_set().  To do this, pass a flag to the
image probe routine indicating whether we want a read-only mapping.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:48:12 -05:00
Alex Elder 6d80b130d5 rbd: kill rbd_dev_clear_mapping()
This function is a duplicate of rbd_dev_mapping_clear(), and was
added by mistake.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:48:12 -05:00
Alex Elder 8f4b7d9821 rbd: don't look up snapshot id in rbd_dev_mapping_set()
Currently rbd_dev_mapping_set() looks up the snapshot id for the
snapshot whose name is found in the rbd device's spec structure.

That function gets called by rbd_dev_device_setup(), which is
called by rbd_add() *after* rbd_dev_image_probe().  If the
image probe succeeds, the rbd device's spec will already have
been updated to include names and ids for all fields.

Therefore there's no need to look up the snapshot id in
rbd_dev_mapping_set().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:48:11 -05:00
Alex Elder c734b79655 rbd: don't print warning if not mapping a parent
The presence of the LAYERING bit in an rbd image's feature mask does
not guarantee the image actually has a parent image.  Currently that
bit is set only when a clone (i.e., image with a parent) is created,
but it is (currently) not cleared if that clone gets flattened back
into a "normal" image.  A "parent_id" query will leave the
parent_spec for the image being mapped a null pointer, but will not
return an error.

Currently, whenever an image with the LAYERED feature gets mapped, a
warning about the use of layered images gets printed.  But we don't
want to do this for a flattened image, so print the warning only
if we find there is a parent spec after the probe.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:48:11 -05:00
Alex Elder 29334ba49c rbd: kill rbd_update_mapping_size()
Since rbd_update_mapping_size() is now a trivial wrapper, just open
code it in its two callers.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:45:39 -05:00
Alex Elder 00a653e216 rbd: update capacity in rbd_dev_refresh()
When a mapped image changes size, we change the capacity recorded
for the Linux disk associated with it, in rbd_update_mapping_size().
That function is called in two places--the format 1 and format 2
refresh routines.

There is no need to set the capacity while holding the header
semaphore.  Instead, do it in the common rbd_dev_refresh(), using
the logic that's already there to initiate disk revalidation.

Add handling in the request function, just in case a request
that exceeds the capacity of the device comes in (perhaps one
that was started before a refresh shrunk the device).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:45:30 -05:00
Alex Elder e627db085e rbd: revalidate only for mapping size changes
This commit:
    d98df63e rbd: revalidate_disk upon rbd resize
instituted a call to revalidate_disk() to notify interested parties
that a mapped image has changed size.  This works well, as long as
the the rbd device doesn't map a snapshot.

A snapshot will never change size.  However, the base image the
snapshot is associated with can, and it can do so while the snapshot
is mapped.

The problem is that the test for the size is looking at the size of
the base image, not the size of the mapped snapshot.  This patch
corrects that.

Update the warning message shown in the event of error, and move
it into the callers.

This resolves:
    http://tracker.ceph.com/issues/4911

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:40:48 -05:00
Alex Elder 49ece55428 rbd: fix leak of format 2 snapshot context
When rbd_dev_v2_refresh() is called, the rbd device already has a
snapshot context associated with it.  But that never gets freed,
the pointer just gets overwritten.

Fix this by dropping the rbd device's reference to the snapshot
context before overwriting the pointer.

Because ceph_put_snap_context() already handles for a null pointer
we don't need to check for that (for the probe case, where no
context has yet been assigned).

This resolves:
    http://tracker.ceph.com/issues/4912

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-08 07:38:30 -05:00
Linus Torvalds 292088ee03 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "A couple of fixes + getting rid of __blkdev_put() return value"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  proc: Use PDE attribute setting accessor functions
  make blkdev_put() return void
  block_device_operations->release() should return void
  mtd_blktrans_ops->release() should return void
  hfs: SMP race on directory close()
2013-05-07 15:14:53 -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
Alex Elder b5b09be30c rbd: fix image request leak on parent read
When a read for a layered image object finds the target object
doesn't exist, a read image request for the parent image is created
and submitted.  When that completes, the callback routine was
not releasing that parent image request.  Fix that.

The slab allocation stuff just added has greatly simplified the
search for the source of this memory leak.

This resolves:
    http://tracker.ceph.com/issues/4803

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 12:15:28 -05:00
Alex Elder 78c2a44aae rbd: allocate image object names with a slab allocator
The names of objects used for image object requests are always fixed
size.  So create a slab cache to manage them.  Define a new function
rbd_segment_name_free() to match rbd_segment_name() (which is what
supplies the dynamically-allocated name buffer).

This is part of:
    http://tracker.ceph.com/issues/3926

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:58:30 -05:00
Alex Elder 868311b1eb rbd: allocate object requests with a slab allocator
Create a slab cache to manage rbd_obj_request allocation.  We aren't
using a constructor, and we'll zero-fill object request structures
when they're allocated.

This is part of:
    http://tracker.ceph.com/issues/3926

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:58:30 -05:00
Alex Elder f907ad5596 rbd: allocate name separate from obj_request
The next patch will define a slab allocator for a object requests.
To use that we'll need to allocate the name of an object separate
from the request structure itself.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:58:29 -05:00
Alex Elder 1c2a9dfe21 rbd: allocate image requests with a slab allocator
Create a slab cache to manage rbd_img_request allocation.  Nothing
too fancy at this point--we'll still initialize everything at
allocation time (no constructor)

This is part of:
    http://tracker.ceph.com/issues/3926

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:58:29 -05:00
Alex Elder 30d1cff817 rbd: use binary search for snapshot lookup
Use bsearch(3) to make snapshot lookup by id more efficient.  (There
could be thousands of snapshots, and conceivably many more.)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:58:17 -05:00
Alex Elder 15228ede7d rbd: clear EXISTS flag if mapped snapshot disappears
This functionality inadvertently disappeared in the last patch.

Image snapshots can get removed at just about any time.  In
particular it can disappear even if it is in use by an rbd
client as a mapped image.

The rbd client deals with such a disappearance by responding to new
requests with ENXIO.  This is implemented by each rbd device
maintaining an EXISTS flag, which is normally set but cleared if a
snapshot disappears.

This patch (re-)implements the clearing of that flag.

Whenever mapped image header information is refreshed, if the
mapping is for a snapshot, verify the mapped snapshot is still
present in the updated snapshot context.  If it is not, clear the
flag.

It is not necessary to check this in the initial probe, because the
probe will not succeed if the snapshot doesn't exist.

This resolves:
    http://tracker.ceph.com/issues/4880

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-02 11:57:03 -05:00
Alex Elder 33dca39f5c rbd: kill off the snapshot list
We no longer use the snapshot list for anything.  When we need to
look up a snapshot name, id, size, or feature mask, we just do it
directly rather than relying on this list being updated with every
refresh.  The main reason it existed was for the benefit of the
device/sysfs entries that previously were associated with snapshots.

So get rid of the snapshot list, and struct rbd_snap, and the
hundreds of lines of code that supported them.

This resolves:
    http://tracker.ceph.com/issues/4868

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:22 -07:00
Alex Elder 2ad3d7167e rbd: define rbd_snap_size() and rbd_snap_features()
This patch defines a handful of new functions that will allow
us to get rid of the rbd device structure's list of snapshots.

Define rbd_snap_id_by_name() to look up a snapshot id given its
name.  This is efficient for format 1 images but not for format 2.
Fortunately it only gets called at mapping time so it's not that
critical.

Use rbd_snap_id_by_name() to find out the id for a snapshot getting
mapped, and pass that id to new functions rbd_snap_size() and
rbd_snap_features() to look up information about a given snapshot's
size and feature mask given its snapshot id.  All this gets done
in rbd_dev_mapping_set().

As a result, snap_by_name() is no longer needed, so get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:20 -07:00
Alex Elder 54cac61fb6 rbd: use snap_id not index to look up snap info
In order to align with what was needed for format 1 rbd images,
rbd_dev_v2_snap_info() was set up to take as argument an index into
the array of snapshot ids in a rbd device's snapshot context.

This switches that around, so we pass the snapshot id instead.
In doing this, rbd_snap_name() now returns a dynamically-allocated
string rather than a fixed one, so there's no need to make a
duplicate in its caller, rbd_dev_spec_update().

This means the following functions take a snapshot id where they
previously used an index value:
    rbd_dev_snap_info()
    rbd_dev_v1_snap_info()
    rbd_dev_v2_snap_info()

A new function, rbd_dev_snap_index(), determines the snap index for
format 1 images and uses it to look up the name.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:19 -07:00
Alex Elder 9682fc6d3a rbd: look up snapshot name in names buffer
Rather than scanning the list of snapshot structures for it, scan
the snapshot context buffer containing snapshot names in order to
determine for a format 1 image the name associated with a given
snapshot id.

Pull out the part of rbd_dev_v1_snap_info() that does this scan into
a new function, _rbd_dev_v1_snap_name().  Have that function return
a dynamically-allocated copy of the name, and don't duplicate it in
rbd_dev_v1_snap_info().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:18 -07:00
Alex Elder dedc81ea84 rbd: drop obj_request->version
Nothing ever uses the version field maintained in the object request
structure any more, so get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:17 -07:00
Alex Elder e2a58ee55b rbd: drop rbd_obj_method_sync() version parameter
Only NULL is passed as the version argument to rbd_obj_method_sync(),
so get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:16 -07:00
Alex Elder cc4a38bdd5 rbd: more version parameter removal
Continued from the last patch, more parameters that can go away
because we no longer have a need to track object versions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:15 -07:00
Alex Elder 7097f8df6e rbd: get rid of some version parameters
Several functions in rbd have parameters meant to allow the version
of an object to be passed in or out.  The purpose of those was to
allow the version of a header object to be maintained, but we no
longer do that.  As a result, these parameters are never actually
needed or used, so get rid of them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:14 -07:00
Alex Elder b21ebdddeb rbd: stop tracking header object version
The rbd code takes care to maintain the version of the header
object.  This was done in hopes of using it to detect a change in
the object between reading it and setting up a watch request to
be notified of changes.

The mechanism was never fully implemented, however.  And we now
avoid the original problem by setting up the watch request before
ever reading the content of the header.

The osd doesn't interpret the object version supplied with a WATCH
osd op, nor does it use the version supplied with a NOTIFY_ACK op
(we can just supply 0 for both).  There is therefore no need to
maintain the header's object version any more, so stop doing so.

We'll be able to simplify some more rbd code in the next few patches
as a result of this.

This resolves:
    http://tracker.ceph.com/issues/3952

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:13 -07:00
Alex Elder cb75223d2b rbd: snap names are pointer to constant data
Make explicit that snapshot names don't change by making functions
return and take parameters that that point to const qualified data.

This resolves:
    http://tracker.ceph.com/issues/4867

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:12 -07:00
Alex Elder a3fbe5d447 rbd: don't revalidate so much
Whenever a header object event causes a mapped rbd image to refresh
its header information, revalidate_disk() is being called.  This was
done in rbd_dev_refresh() outside the control mutex in order to
avoid a lock inversion.  Although a an event like this *might*
indicate the image has changed size, most of the time it does not.

Record the image size before and after the refresh, and only
call revalidate_disk() if it changes.

This resolves:
    http://tracker.ceph.com/issues/4867

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:11 -07:00
Alex Elder 96882f55c4 rbd: fix up the layering warning message
A warning gets spewed for any image being probed, including parent
images.  Set up a condition such that the warning message only gets
printed for the image being mapped, not any of its parents.

Also, I didn't like the way the warning ended up being so long.
Make it a terse warning instead.  People experimenting with layering
will know what the message means.

This is part of:
    http://tracker.ceph.com/issues/4867

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:10 -07:00
Alex Elder 812164f8c3 ceph: use ceph_create_snap_context()
Now that we have a library routine to create snap contexts, use it.

This is part of:
    http://tracker.ceph.com/issues/4857

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:09 -07:00
Alex Elder b536f69a3a rbd: set up devices only for mapped images
Stop setting up Linux devices during the image probe operation.
Instead, set up the devices as a separate step after the image
probe, in rbd_add().

A consequence of this is that only mapped images get devices
assigned to them, which is pretty sweet.

This resolves:
    http://tracker.ceph.com/issues/4774

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:07 -07:00
Alex Elder 8ad42cd0c0 rbd: don't have device release destroy rbd_dev
Currently an rbd_device structure gets destroyed from the release
routine for the device embedded within it.  Stop doing that, instead
calling rbd_dev_image_release() right after rbd_bus_del_dev()
wherever the latter is called.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:05 -07:00
Alex Elder 6fd48b3be9 rbd: define rbd_dev_unprobe()
Define a new function rbd_dev_unprobe() which undoes state changes
that occur from calling rbd_dev_v1_probe() or rbd_dev_v2_probe().
Note that this is a superset of rbd_header_free(), which is now
getting removed (it seems to have been used improperly anyway).

Flesh out rbd_dev_image_release() so it undoes exactly what
rbd_dev_image_probe() does.

This means that:
    - rbd_dev_device_release() gets called when the last device
      reference gets dropped;
    - that undoes everything done by the rbd_dev_device_setup() call
      at the end of rbd_dev_image_probe() (and nothing more), ending
      by calling rbd_dev_image_release(); and
    - rbd_dev_image_release() undoes everything else done by
      rbd_dev_image_probe() (and this includes a call to
      rbd_dev_unprobe().

This means the image and device portions of an rbd device are fairly
cleanly separated now, so error paths should be a little easier to
verify than they used to be.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:04 -07:00
Alex Elder 200a6a8be5 rbd: don't destroy rbd_dev in device release function
Rename rbd_dev_probe_finish() to be rbd_dev_device_setup().  Its
purpose is to set up the Linux side of an rbd device mapping.
Rename rbd_dev_release() to be rbd_dev_device_release(), making
it more obvious it serves as the inverse of the setup function
(or it will).

Encapsulate some of what was done in rbd_dev_release() into a new
function rbd_dev_image_release(), which serves as the inverse of
setting up the ceph side of the mapped rbd image.

Define a new helper rbd_dev_clear_mapping() to simply zero out the
fields of a mapping structure--the inverse of rbd_dev_set_mapping().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:03 -07:00
Alex Elder 79ab7558aa rbd: drop module later
Drop the module reference at the end of rbd_remove() for symmetry
with adding a reference at the top of rbd_add().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:02 -07:00
Alex Elder b644de2ba0 rbd: set up watch in rbd_dev_image_probe()
Move setting up the watch request for an image so it's done in
rbd_dev_image_probe() rather than rbd_dev_probe_finish().  Move
it all the way up to before doing the initial probe.  This avoids
a potential race condition, in which we get (and use) the initial
snapshot context for an image, and it gets changed between that
time and the time we get the watch set up.

This resolves:
    http://tracker.ceph.com/issues/3871

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:01 -07:00
Alex Elder 96f03e08f9 rbd: don't bother checking whether order changes
When a format 2 image is refreshed, code is in place to verify that
the object order never changes from what it was originally.  This
relies on the fact that the refresh will occur *after* an initial
load of information about the image.

An upcoming patch makes it possible for the refresh to occur first,
so we can no longer make this order check.  The order really can't
ever change anyway--this was just a sanity check.  So get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:20:00 -07:00
Alex Elder 0d8189e175 rbd: don't clean up watch in device release function
Currently, a watch on an rbd device header object gets torn down
when its final Linux device reference gets dropped.  Instead, tear
it down when removing the device.  If an error occurs cleaning up
the watch event when unmapping, abort the unmap request.

All images (including parents) still get watch requests set up, so
tear these down also, in rbd_dev_remove_parent().  For now, ignore
any errors that occur in this case.

Get rid of local variable "rc" in rbd_remove(); use "ret" instead
(they both somehow ended up defined in the function and only one is
needed).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:59 -07:00
Alex Elder 332bb12db9 rbd: define rbd_header_name()
Define a new function rbd_header_name(), which allocates and formats
the name of the header object for the rbd device.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:58 -07:00
Alex Elder 9bb81c9be9 rbd: move more initialization into rbd_dev_image_probe()
Move a block of initialization related to the "ceph-side" of an rbd
image out of rbd_dev_probe_finish() and into rbd_dev_image_probe().

Add appropriate error handling to clean things up in the event any
of these new functions return an error.

We know that rbd_dev_snaps_update(), rbd_dev_spec_update(), and
rbd_dev_probe_parent() all clean up after themselves before they
return an error, so no special cleanup is required except when an
earlier call succeeds.  Since rbd_dev_spec_update() only updates the
spec field (whose cleanup will be handled by dropping the last
reference to the spec) there is no cleanup action associatied with
that.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:57 -07:00
Alex Elder 5de10f3b0c rbd: probe for the parent earlier
Probe for a parent device earlier in rbd_dev_probe_finish(), before
starting to set up the Linux side of the rbd device.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:56 -07:00
Alex Elder 2e93bf9e46 rbd: remove parent devices on probe error
When an error occurs while finishing probing a device it is assumed
that parent devices get cleaned up when deleting a device.  They
don't.  Add a call to clean them up.  Note that this means the
parent spec will already be cleaned up so it doesn't have to be
in one of the rbd_add() error paths.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:55 -07:00
Alex Elder ad945fc1da rbd: fix rbd_dev_remove_parent()
In certain error paths, it is possible for an rbd device to have a
parent spec but no parent rbd_dev.  In rbd_dev_remove_parent() use
the parent field rather than parent_spec in determining whether to
try to remove any parent devices.  Use assertions to indicate that
any non-null parent pointer has parent_spec associated with it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:54 -07:00
Alex Elder b480815a17 rbd: kill __rbd_remove()
The function __rbd_remove() is used in two spots, and it's fairly
simple.  It combines cleanup of part of the ceph-side state as well
as cleaning up the Linux-side state.  Just open code it in the two
callers and eliminate the function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:53 -07:00
Alex Elder d1cf578845 rbd: set mapping info earlier
Set the mapping size and features earlier in rbd_dev_probe_finish().

Define rbd_dev_mapping_clear() as an inverse for setting those
fields, and use it both in error handling in rbd_dev_image_probe()
and in the final cleanup in rbd_dev_release().  Change the name
of rbd_dev_set_mapping() to of rbd_dev_mapping_set().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:51 -07:00
Alex Elder 05a46afdc7 rbd: encapsulate removing parent devices
Encapsulate the code that removes an rbd device's parent images into
a new function, rbd_dev_remove_parent().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:50 -07:00
Alex Elder 124afba25d rbd: encapsulate probing for parent devices
Encapsulate the code that probes for an rbd device's parent images
into a new function, rbd_dev_probe_parent().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:49 -07:00
Alex Elder b5156e76da rbd: defer setting disk capacity
Don't set the disk capacity until right before we announce the
device as available for use.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:48 -07:00
Alex Elder 129b79d449 rbd: only set device exists flag when ready
Hold off setting the EXISTS rbd device flag until just before we
announce the disk as available for use.  There's no point in doing
so any earlier than that, and at that point the device truly is
fully set up and ready to use.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:47 -07:00
Alex Elder fc71d8330e rbd: fix up some sysfs stuff
This just tweaks a few things in the routines that implement
rbd sysfs files.

All of the entries for an rbd device in /sys/bus/rbd/devices/<id>/
will represent information whose valid values are known by the time
they are accessible.

Right now we get the size of the mapped image by a call to
get_capacity().  There's no need to do this, because that will
return what we last set the capacity to, which is just the size
recorded for the mapping.  So just show that value instead.

We also get this under protection of the header semaphore, in order
to provide a precisely correct value.  This isn't really necessary;
these files are really informational only and it's not necessary to
be so careful.

Finally, print a special value in case the major device number is
not recorded.  Right now that won't matter much but soon the parent
images won't have devices associated with them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:46 -07:00
Alex Elder e28626a08b rbd: fix a bug in resizing a mapping
When a snapshot context update occurs, rbd_update_mapping_size() is
called to set the capacity of the disk to record the updated
size of the image in case it has changed.

There's a bug though.  The mapping size is in units of *bytes*.  The
code that updates the mapping size field is assigning a value that
has been scaled down to *sectors*.

Fix that.  Also, check to see if the size has actually changed, and
don't bother updating things (specifically, calling set_capacity())
if it has not.

This resolves:
    http://tracker.ceph.com/issues/4833

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:45 -07:00
Alex Elder 2e9f7f1c0d rbd: refactor rbd_dev_probe_update_spec()
Fairly straightforward refactoring of rbd_dev_probe_update_spec().
The name is changed to rbd_dev_spec_update().

Rearrange it so nothing gets assigned to the spec until all of the
names have been successfully acquired.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:44 -07:00
Alex Elder 71f293e26e rbd: rename rbd_dev_probe()
Rename rbd_dev_probe() to be rbd_dev_image_probe().  Its purpose
will eventually be to probe for the existence of a valid rbd image
for the rbd device--focusing only on the ceph side and not the Linux
device side of initialization.

For now the two "sides" are not fully separated, and this function
is still the entry point for initializing the full rbd device.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:43 -07:00
Alex Elder 9f5dffdc8f rbd: make rbd_dev_destroy() match rbd_dev_create()
Currently, rbd_dev_destroy() does more than just the inverse of what
rbd_dev_create() does.  Stop doing that, and move the two extra
things it does into the three call sites.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:42 -07:00
Alex Elder 468521c1b1 rbd: define rbd snap context routines
Encapsulate the creation of a snapshot context for rbd in a new
function rbd_snap_context_create().  Define rbd wrappers for getting
and dropping references to them once they're created.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:41 -07:00
Alex Elder c0cd10db46 rbd: use rbd_warn(), not WARN_ON()
Change some calls to WARN_ON() so they use rbd_warn() instead, so we
get consistent messaging.  A few remain but they can probably just
go away eventually.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:40 -07:00
Alex Elder 500d0c0fbb rbd: move stripe_unit and stripe_count into header
This commit added fetching if fancy striping parameters:
    09186ddb rbd: get and check striping parameters

They are almost unused, but the two fields storing the information
really belonged in the rbd_image_header structure.

This patch moves them there.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:39 -07:00
Alex Elder ecb4dc2256 rbd: make rbd spec names pointer to const
Make the names and image id in an rbd_spec be pointers to constant
data.  This required the use of a local variable to hold the
snapshot name in rbd_add_parse_args() to avoid a warning.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:37 -07:00
Alex Elder e1d4213f09 rbd: set snapshot id in rbd_dev_probe_update_spec()
Set the rbd spec's snapshot id for an image getting mapped in
rbd_dev_probe_update_spec() rather than rbd_dev_set_mapping().
This is the more logical place for that to happen (even though
it means we might look up the snapshot by name twice).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:36 -07:00
Alex Elder 8b0241f85a rbd: have snap_by_name() return a snapshot
A function called snap_by_name() ought to just look up a snapshot by
name.  It does that, but then it assigns some stuff to the rbd
device structure as well.

Change the function to do just the lookup, and have the caller do
the assignments that follow.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:35 -07:00
Alex Elder 5655c4d940 rbd: fix image id leak in initial probe
If a format 2 image id is found for an image being mapped, but the
subsequent probe of the image fails, rbd_dev_probe() quits without
freeing the image id.  Fix that.

Also drop a redundant hunk of code in rbd_dev_image_id().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:34 -07:00
Alex Elder c0fba36880 rbd: have rbd_dev_image_id() set format 1 image id
Currently, rbd_dev_probe() assumes that any error returned by
rbd_dev_image_id() is most likely -ENOENT, and responds by
calling the format 1 probe routine, rbd_dev_v1_probe().  Then,
at the top of rbd_dev_v1_probe(), an empty string is allocated
for the image id.

This is sort of unbalanced.  Fix this by having rbd_dev_image_id()
look for -ENOENT from its "get_id" method call.  If that is seen,
have it allocate the empty string there rather than depending on
rbd_dev_v1_probe() to do it.

Given that this is effectively defining the format of the image,
set rbd_dev->image_format inside rbd_dev_image_id() rather than in
the format-specific probe routines.

Also drop a redundant hunk of code in rbd_dev_image_id().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:33 -07:00
Alex Elder a0cab92432 rbd: avoid dropping extra reference in rbd_free_disk()
I found during some failure injection testing that the call to
rbd_free_disk() in the error path of rbd_dev_probe_finish() was
dropping an extra reference to the disk queue.  The problem
occurred when put_disk tried to drop a reference to the disk's
queue.  A call to blk_cleanup_queue() just prior to that will have
also dropped a reference to the queue.

The problem is that the reference dropped by put_disk() is assumed
to have been taken by add_disk().  Our code has error paths that can
occur after the disk and its queue are initialized, but before the
call to add_disk(), and in those paths we won't have that extra
reference.

The fix is easy though.  In rbd_free_disk() we're already checking
the disk's GENHD_FL_UP flag.  That flag is an indication that
add_disk() has been called, so just call blk_cleanup_queue()
conditional on that flag being set.

This resolves:
    http://tracker.ceph.com/issues/4800

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:32 -07:00
Alex Elder f40eb349e0 rbd: use rbd_obj_method_sync() return value
Now that rbd_obj_method_sync() returns the number of bytes
returned by the method call, that value should be used by
callers to ensure we don't overrun the valid portion of the
buffer.

Fix the two spots that remained that weren't doing that,
rbd_dev_image_name() and rbd_dev_v2_snap_name().

Rearrange the error path slightly in rbd_dev_v2_snap_name().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:31 -07:00
Alex Elder 6e584f5244 rbd: fix leak of format 2 snapshot names
When the snapshot context for an rbd device gets updated (or the
initial one is recorded) a a list of snapshot structures is created
to represent them, one entry per snapshot.  Each entry includes a
dynamically-allocated copy of the snapshot name.

Currently the name is allocated in rbd_snap_create(), as a duplicate
of the passed-in name.

For format 1 images, the snapshot name provided is just a pointer to
an existing name.  But for format 2 images, the passed-in name is
already dynamically allocated, and in the the process of duplicating
it here we are leaking the passed-in name.

Fix this by dynamically allocating the name for format 1 snapshots
also, and then stop allocating a duplicate in rbd_snap_create().

Change rbd_dev_v1_snap_info() so none of its parameters is
side-effected unless it's going to return success.

This is part of:
    http://tracker.ceph.com/issues/4803

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:30 -07:00
Alex Elder 6087b51b9e rbd: rename __rbd_add_snap_dev()
Rename __rbd_add_snap_dev() to be rbd_snap_create().  We no longer
have devices for non-mapped snapshots, and we're not actually
"adding" it to the list in this function, just creating it.

Rename rbd_remove_snap_dev() to be rbd_snap_destroy() for reasons
similar to the above.  Stop having this function delete the snapshot
from its list (to be symmetrical with its create counterpart) and do
that in the caller instead.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:29 -07:00
Alex Elder acb1b6caf1 rbd: only update values on snap_info success
Change rbd_dev_v2_snap_info() so it only ever sets values of the
size and features parameters if looking up the snapshot name was
successful.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:28 -07:00
Alex Elder c86f86e9e7 rbd: make snap_size order parameter optional
Only one of the two callers of _rbd_dev_v2_snap_size() needs the
order value returned.  So make that an optional argument--a null
pointer if the caller doesn't need it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:27 -07:00
Alex Elder 522a0cc0f0 rbd: fix leak of snapshots during initial probe
When an rbd image is initially mapped, its snapshot context is
collected, and then a list of snapshot entries representing the
snapshots in that context is created.  The list is created using
rbd_dev_snaps_update().  (This function also supports updating an
existing snapshot list based on a new snapshot context.)

If an error occurs, updating the list is aborted, and the list is
currently left as-is, in an inconsistent state.  At that point,
there may be a partially-constructed list, but the calling functions
(rbd_dev_probe_finish() from rbd_dev_probe() from rbd_add()) never
clean them up.  So this constitutes a leak.

A snapshot list that is inconsistent with the current snapshot
context is of no use, and might even be actively bad.  So rather
than just having the caller clean it up, have rbd_dev_snaps_update()
just clear out the entire snapshot list in the event an error
occurs.

The other place rbd_dev_snaps_update() is used is when a refresh is
triggered, either because of a watch callback or via a write to the
/sys/bus/rbd/devices/<id>/refresh interface.  An error while
updating the snapshots has no substantive effect in either of those
cases, but one of them issues a warning.  Move that warning to the
common rbd_dev_refresh() function so it gets issued regardless of
how it got initiated.

This is part of:
    http://tracker.ceph.com/issues/4803

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:26 -07:00
Alex Elder 3e83b65bb9 rbd: don't create sysfs entries for non-mapped snapshots
When an rbd image gets mapped a device entry gets created for it
under /sys/bus/rbd/devices/<id>/.  Inside that directory there are
sysfs files that contain information about the image: its size,
feature bits, major device number, and so on.

Additionally, if that image has any snapshots, a device entry gets
created for each of those as a "child" of the mapped device.  Each
of these is a subdirectory of the mapped device, and each directory
contains a few files with information about the snapshot (its
snapshot id, size, and feature mask).

There is no clear benefit to having those device entries for the
snapshots.  The information provided via sysfs of of little real
value--and all of it is available via rbd CLI commands.  If we
still wanted to see the kernel's view of this information it could
be done much more simply by including it in a single sysfs file for
the mapped image.

But there *is* a clear cost to supporting them.  Every time a snapshot
context changes, these entries need to be updated (deleted snapshots
removed, new snapshots created).  The rbd driver is notified of
changes to the snapshot context via callbacks from an osd, and care
must be taken to coordinate removal of snapshot data structures
with the possibility of one these notifications occurring.

Things would be considerably simpler if we just didn't have to
maintain device entries for the snapshots.

So get rid of them.

The ability to map a snapshot of an rbd image will remain; the only
thing lost will be the ability to query these sysfs directories for
information about snapshots of mapped images.

This resolves:
    http://tracker.ceph.com/issues/4796

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:25 -07:00
Alex Elder 770eba6e29 rbd: activate support for layered images
Now that we have most everything in place to support layered rbd
images, enable support for them in the kernel client.  Issue a
warning to the log that the support is considered experimental
whenever a format 2 layered image is mapped.

Note that we also have to claim to support the STRIPINGV2 feature,
due to a mistake in the way the rbd CLI set up those flags.  This
feature can work if it has the right parameters, and safeguards
have been put in place to reject those images that do not have
compatible parameters.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:23 -07:00
Alex Elder cc070d59bc rbd: get and check striping parameters
If an rbd format 2 image indicates it supports the STRIPINGV2
feature we need to find out its stripe unit and stripe count in
order to know whether we can use it.  We don't yet support fancy
striping fully, but if the default parameters are used the behavior
is indistinguishible from non-fancy striping.

This is necessary because some images require the STRIPINGV2 feature
even if they use the default parameters.  (Which is to say the feature
bit was erroneously set even if the feature was not used.)

This resolves:
    http://tracker.ceph.com/issues/4709

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:21 -07:00
Alex Elder 57385b51c3 rbd: have rbd_obj_method_sync() return transfer count
Callers of rbd_obj_method_sync() don't know how many bytes of data
got returned by the class method call.  As a result, they have been
assuming enough got returned to decode whatever was expected.

This isn't safe.  We know how many bytes got transferred, so have
rbd_obj_method_sync() return that amount (rather than just 0) if
the call is successful.

Change all callers to use this return value to ensure decoding of
the results is done safely.

On the other hand, most callers of rbd_obj_method_sync() only
indicate success or failure, so all of *their* callers can simply
test for non-zero result.

This resolves:
    http://tracker.ceph.com/issues/4773

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:20 -07:00
Alex Elder 4157976b27 rbd: void data pointers for rbd_obj_method_sync()
Make the inbound and outbound data parameters have void rather than
character type for rbd_obj_method_sync().  This makes it more clear
they don't expect typed data, and eliminates the need for some silly
type casts.

One more unrelated change: define the features buffer used in
_rbd_dev_v2_snap_features() to be a packed data structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:19 -07:00
Alex Elder 80ef15bf71 rbd: give rbd_obj_read_sync() buffer void type
Make the buf parameter into which the data is to be read have type
void pointer.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:18 -07:00
Alex Elder a9e8ba2cb3 rbd: enforce parent overlap
A clone image has a defined overlap point with its parent image.
That is the byte offset beyond which the parent image has no
defined data to back the clone, and anything thereafter can be
viewed as being zero-filled by the clone image.

This is needed because a clone image can be resized.  If it gets
resized larger than the snapshot it is based on, the overlap defines
the original size.  If the clone gets resized downward below the
original size the new clone size defines the overlap.  If the clone
is subsequently resized to be larger, the overlap won't be increased
because the previous resize invalidated any parent data beyond that
point.

This resolves:
    http://tracker.ceph.com/issues/4724

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:15 -07:00
Alex Elder 0eefd470f0 rbd: issue a copyup for layered writes
This implements the main copyup functionality for layered writes.

Here we add a copyup_pages field to the object request, which is
used only for copyup requests to keep track of the page array
containing data read from the parent image.

A copyup request is currently the only request rbd has that requires
two osd operations.  Because of this we handle copyup specially.
All image object requests get an osd request allocated when they are
created.  For a write request, if a copyup is required, the osd
request originally allocated is released, and a new one (with room
for two osd ops) is allocated to replace it.  A new function
rbd_osd_req_create_copyup() allocates an osd request suitable for
a copyup request.

The first op is then filled with a copyup object class method call,
supplying the array of pages containing data read from the parent.
The second op is filled in with the original write request.

The original request otherwise remains intact, and it describes the
original write request (found in the second osd op).  The presence
of the copyup op is sort of implicit; a non-null copyup_pages field
could be used to distinguish between a "normal" write request and a
request containing both a copyup call and a write.

This resolves:
    http://tracker.ceph.com/issues/3419

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:14 -07:00
Alex Elder 3d7efd18d9 rbd: implement full object parent reads
As a step toward implementing layered writes, implement reading the
data for a target object from the parent image for a write request
whose target object is known to not exist.  Add a copyup_pages field
to an image request to track the page array used (only) for such a
request.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:13 -07:00
Laurent Barbe d98df63ea7 rbd: revalidate_disk upon rbd resize
If rbd disk is open and rbd resize is done, new size is not
visible by filesystem.  Like is done in virtio-blk and dm driver,
revalidate_disk() permits to update the bd_inode size.

Signed-off-by: Laurent Barbe <laurent@ksperis.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2013-05-01 21:19:12 -07:00
Alex Elder f1a4739f33 rbd: support page array image requests
This patch adds the ability to build an image request whose data
will be written from or read into memory described by a page array.
(Previously only bio lists were supported.)

Originally this was going to define a new function for this purpose
but it was largely identical to the rbd_img_request_fill_bio().  So
instead, rbd_img_request_fill_bio() has been generalized to handle
both types of image request.

For the moment we still only fill image requests with bio data.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:11 -07:00
Alex Elder b9434c5b43 rbd: define zero_pages()
Define a new function zero_pages() that zeroes a range of memory
defined by a page array, along the lines of zero_bio_chain().  It
saves and the irq flags like bvec_kmap_irq() does, though I'm not
sure at this point that it's necessary.

Update rbd_img_obj_request_read_callback() to use the new function
if the object request contains page rather than bio data.

For the moment, only bio data is used for osd READ ops.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:10 -07:00
Alex Elder b454e36d26 rbd: encapsulate submission of image object requests
Object requests that are part of an image request are subject to
some additional handling.  Define rbd_img_obj_request_submit() to
encapsulate that, and use it when initially submitting an image
object request, and when re-submitting it during callback of
an object existence check.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:08 -07:00
Alex Elder 9d4df01f08 rbd: define separate read and write format funcs
Separate rbd_osd_req_format() into two functions, one for read
requests and the other for write requests.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:07 -07:00
Alex Elder c5b5ef6c51 rbd: issue stat request before layered write
This is a step toward fully implementing layered writes.

Add checks before request submission for the object(s) associated
with an image request.  For write requests, if we don't know that
the target object exists, issue a STAT request to find out.  When
that request completes, mark the known and exists flags for the
original object request accordingly and re-submit the object
request.  (Note that this still does the existence check only; the
copyup operation is not yet done.)

A new object request is created to perform the existence check.  A
pointer to the original request is added to that object request to
allow the stat request to re-issue the original request after
updating its flags.  If there is a failure with the stat request
the error code is stored with the original request, which is then
completed.

This resolves:
    http://tracker.ceph.com/issues/3418

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:04 -07:00
Alex Elder 5679c59f60 rbd: add target object existence flags
This creates two new flags for object requests to indicate what is
known about the existence of the object to which a request is to be
sent.  The KNOWN flag will be true if the the EXISTS flag is
meaningful.  That is:

    KNOWN   EXISTS
    -----   ------
      0       0     don't know whether the object exists
      0       1     (not used/invalid)
      1       0     object is known to not exist
      1       0     object is known to exist

This will be used in determining how to handle write requests for
data objects for layered rbd images.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:03 -07:00
Alex Elder 57acbaa7fb rbd: always check IMG_DATA flag
In a few spots, whether the an object request's img_request pointer
is null is used to determine whether an object request is being done
as part of an image data request.

Stop doing that, and instead always use the object request IMG_DATA
flag for that purpose.  Swap the order of the definition of the
IMG_DATA and DONE flag helpers, because obj_request_done_set() now
refers to obj_request_img_data_set() to get its rbd_dev value.

This will become important because the img_request pointer is
about to become part of a union.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:02 -07:00
Alex Elder b155e86cf6 rbd: adjust image object request ref counting
An extra reference is taken when an object request is added as one
of the requests making up an image object.  A reference is dropped
again when the image's object requests get submitted.

The original reference for the object request will remain throughout
this period, so we don't need to add and then take away an extra
one.

This can be interpreted as the image request inheriting the original
object request's reference.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:19:01 -07:00
Alex Elder 406e2c9f92 libceph: kill off osd data write_request parameters
In the incremental move toward supporting distinct data items in an
osd request some of the functions had "write_request" parameters to
indicate, basically, whether the data belonged to in_data or the
out_data.  Now that we maintain the data fields in the op structure
there is no need to indicate the direction, so get rid of the
"write_request" parameters.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:58 -07:00
Alex Elder 8b3e1a5698 rbd: implement layered reads
Implement layered read requests for format 2 rbd images.

If an rbd image is a clone of a snapshot, the snapshot will be the
clone's "parent" image.  When an object read request on a clone
comes back with ENOENT it indicates that the clone is not yet
populated with that portion of the image's data, and the parent
image should be consulted to satisfy the read.

When this occurs, a new image request is created, directed to the
parent image.  The offset and length of the image are the same as
the image-relative offset and length of the object request that
produced ENOENT.  Data from the parent image therefore satisfies the
object read request for the original image request.

While this code works, it will not be active until we enable the
layering feature (by adding RBD_FEATURE_LAYERING to the value of
RBD_FEATURES_SUPPORTED).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:48 -07:00
Alex Elder 2f82ee54d9 rbd: probe the parent of an image if present
Call the probe function for the parent device if one is present.
Since we don't formally support the layering feature we won't
be using this functionality just yet.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:47 -07:00
Alex Elder 6365d33a27 rbd: add an object request flag for image data objects
Add a flag to distinguish between object requests being done on
standalone objects and requests being sent for objects representing
rbd image data (i.e., object requests that are the result of image
request).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:46 -07:00
Alex Elder 926f9b3f08 rbd: define an rbd object request flags field
We're going to need some more Boolean values for object requests,
so create a flags bit field and use it to record whether the request
is done.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:44 -07:00
Alex Elder 1217857fbf rbd: encapsulate image object end request handling
Encapsulate the code that completes processing of an object request
that's part of an image request.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:43 -07:00
Alex Elder d0b2e94455 rbd: define image request layered flag
Define a flag indicating whether an image request is for a layered
image (one with a parent image to which requests will be redirected
if the target object of a request does not exist).  The code that
checks this flag will be added shortly.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:42 -07:00
Alex Elder 9849e98636 rbd: define image request originator flag
Define a flag indicating whether an image request originated from
the Linux block layer (from blk_fetch_request()) or whether it was
initiated in order to satisfy an object request for a child image
of a layered rbd device.  For image requests initiated by objects of
child images we'll save a pointer to the object request rather than
the Linux block request.

For now, only block requests are used.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:41 -07:00
Alex Elder 0c425248e0 rbd: define image request flags
There are several Boolean values we'll be maintaining for image
requests.  Switch from the single write_request field to a
general-purpose flags field, and use one if its bits to represent
the direction of I/O for the image request.  Define helper functions
for setting and testing that flag.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:40 -07:00
Alex Elder 7da22d296d rbd: record image-relative offset in object requests
For an image object request we will need to know what offset within
the rbd image the request covers.  Record that when the object
request gets created.

Update the I/O error warnings so they use this so what's reported
is more informative.

Rename a local variable to fit the convention used everywhere else.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:39 -07:00
Alex Elder 55f27e0931 rbd: record aggregate image transfer count
Compute the total number of bytes transferred for an image
request--the sum across each of the request's object requests.
To avoid contention do it only when all object requests are
complete, in rbd_img_request_complete().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:38 -07:00
Alex Elder a5a337d438 rbd: record overall image request result
If any image object request produces a non-zero result, preserve
that as the result of the overall image request.  If multiple
objects have non-zero results, save only the first one.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:37 -07:00
Alex Elder 5cbf6f12c4 rbd: update feature bits
There is a new rbd feature bit defined for "fancy striping." Add
it to the ones defined in the kernel client.

Change RBD_FEATURES_ALL so it represents the set of all feature
bits (rather than just the ones we support).  Define a new symbol
RBD_FEATURES_SUPPORTED to indicate the supported ones.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:36 -07:00
Alex Elder 04017e29bb libceph: make method call data be a separate data item
Right now the data for a method call is specified via a pointer and
length, and it's copied--along with the class and method name--into
a pagelist data item to be sent to the osd.  Instead, encode the
data in a data item separate from the class and method names.

This will allow large amounts of data to be supplied to methods
without copying.  Only rbd uses the class functionality right now,
and when it really needs this it will probably need to use a page
array rather than a page list.  But this simple implementation
demonstrates the functionality on the osd client, and that's enough
for now.

This resolves:
    http://tracker.ceph.com/issues/4104

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:35 -07:00
Alex Elder a4ce40a9a7 libceph: combine initializing and setting osd data
This ends up being a rather large patch but what it's doing is
somewhat straightforward.

Basically, this is replacing two calls with one.  The first of the
two calls is initializing a struct ceph_osd_data with data (either a
page array, a page list, or a bio list); the second is setting an
osd request op so it associates that data with one of the op's
parameters.  In place of those two will be a single function that
initializes the op directly.

That means we sort of fan out a set of the needed functions:
    - extent ops with pages data
    - extent ops with pagelist data
    - extent ops with bio list data
and
    - class ops with page data for receiving a response

We also have define another one, but it's only used internally:
    - class ops with pagelist data for request parameters

Note that we *still* haven't gotten rid of the osd request's
r_data_in and r_data_out fields.  All the osd ops refer to them for
their data.  For now, these data fields are pointers assigned to the
appropriate r_data_* field when these new functions are called.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:23 -07:00
Alex Elder 2169238dd3 rbd: rearrange some code for consistency
This patch just trivially moves around some code for consistency.

In preparation for initializing osd request data fields in
ceph_osdc_build_request(), I wanted to verify that rbd did in fact
call that immediately before it called ceph_osdc_start_request().
It was true (although image requests are built in a group and then
started as a group).  But I made the changes here just to make
it more obvious, by making all of the calls follow a common
sequence:
	osd_req_op_<optype>_init();
	ceph_osd_data_<type>_init()
	osd_req_op_<optype>_<datafield>()
	rbd_osd_req_format()
	...
	ret = rbd_obj_request_submit()

I moved the initialization of the callback for image object requests
into rbd_img_request_fill_bio(), again, for consistency.  To avoid
a forward reference, I moved the definition of rbd_img_obj_callback()
up in the file.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:18 -07:00
Alex Elder 44cd188d48 rbd: separate initialization of osd data
The osd data for a request is currently initialized inside
rbd_osd_req_create(), but that assumes an object request's data
belongs in the osd request's data in or data out field.

There are only three places where requests with data are set up, and
it turns out it's easier to call just the osd data init routines
directly there rather than handling it in rbd_osd_req_create().

(The real motivation here is moving toward getting rid of the
osd request in and out data fields.)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:17 -07:00
Alex Elder 2fa123201a rbd: don't set data in rbd_osd_req_format_op()
Currently an object request has its osd request's data field set in
rbd_osd_req_format_op().  That assumes a single osd op per object
request, and that won't be the case for long.

Move the code that sets this out and into the caller.

Rename rbd_osd_req_format_op() to be just rbd_osd_req_format(),
removing the notion that it's doing anything op-specific.

This and the next patch resolve:
    http://tracker.ceph.com/issues/4658

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:16 -07:00
Alex Elder c99d2d4abb libceph: specify osd op by index in request
An osd request now holds all of its source op structures, and every
place that initializes one of these is in fact initializing one
of the entries in the the osd request's array.

So rather than supplying the address of the op to initialize, have
caller specify the osd request and an indication of which op it
would like to initialize.  This better hides the details the
op structure (and faciltates moving the data pointers they use).

Since osd_req_op_init() is a common routine, and it's not used
outside the osd client code, give it static scope.  Also make
it return the address of the specified op (so all the other
init routines don't have to repeat that code).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:18:15 -07:00