Commit graph

655 commits

Author SHA1 Message Date
David Sterba 10a3a3edc5 btrfs: log message when rw remount is attempted with unclean tree-log
A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.

A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:17:00 +01:00
Josef Bacik d55966c427 btrfs: do not zero f_bavail if we have available space
There was some logic added a while ago to clear out f_bavail in statfs()
if we did not have enough free metadata space to satisfy our global
reserve.  This was incorrect at the time, however didn't really pose a
problem for normal file systems because we would often allocate chunks
if we got this low on free metadata space, and thus wouldn't really hit
this case unless we were actually full.

Fast forward to today and now we are much better about not allocating
metadata chunks all of the time.  Couple this with d792b0f197 ("btrfs:
always reserve our entire size for the global reserve") which now means
we'll easily have a larger global reserve than our free space, we are
now more likely to trip over this while still having plenty of space.

Fix this by skipping this logic if the global rsv's space_info is not
full.  space_info->full is 0 unless we've attempted to allocate a chunk
for that space_info and that has failed.  If this happens then the space
for the global reserve is definitely sacred and we need to report
b_avail == 0, but before then we can just use our calculated b_avail.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: ca8a51b3a9 ("btrfs: statfs: report zero available if metadata are exhausted")
CC: stable@vger.kernel.org # 4.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-02 18:49:32 +01:00
Dennis Zhou b0643e59cf btrfs: add the beginning of async discard, discard workqueue
When discard is enabled, everytime a pinned extent is released back to
the block_group's free space cache, a discard is issued for the extent.
This is an overeager approach when it comes to discarding and helping
the SSD maintain enough free space to prevent severe garbage collection
situations.

This adds the beginning of async discard. Instead of issuing a discard
prior to returning it to the free space, it is just marked as untrimmed.
The block_group is then added to a LRU which then feeds into a workqueue
to issue discards at a much slower rate. Full discarding of unused block
groups is still done and will be addressed in a future patch of the
series.

For now, we don't persist the discard state of extents and bitmaps.
Therefore, our failure recovery mode will be to consider extents
untrimmed. This lets us handle failure and unmounting as one in the
same.

On a number of Facebook webservers, I collected data every minute
accounting the time we spent in btrfs_finish_extent_commit() (col. 1)
and in btrfs_commit_transaction() (col. 2). btrfs_finish_extent_commit()
is where we discard extents synchronously before returning them to the
free space cache.

discard=sync:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    ---------------------------------------------------------------
     Drive A  |           434           |          1170
     Drive B  |           880           |          2330
     Drive C  |          2943           |          3920
     Drive D  |          4763           |          5701

discard=async:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    --------------------------------------------------------------
     Drive A  |           134           |           956
     Drive B  |            64           |          1972
     Drive C  |            59           |          1032
     Drive D  |            62           |          1200

While it's not great that the stats are cumulative over 1m, all of these
servers are running the same workload and and the delta between the two
are substantial. We are spending significantly less time in
btrfs_finish_extent_commit() which is responsible for discarding.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Dennis Zhou 46b27f5059 btrfs: rename DISCARD mount option to to DISCARD_SYNC
This series introduces async discard which will use the flag
DISCARD_ASYNC, so rename the original flag to DISCARD_SYNC as it is
synchronously done in transaction commit.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Linus Torvalds 0da522107e compat_ioctl: remove most of fs/compat_ioctl.c
As part of the cleanup of some remaining y2038 issues, I came to
 fs/compat_ioctl.c, which still has a couple of commands that need support
 for time64_t.
 
 In completely unrelated work, I spent time on cleaning up parts of this
 file in the past, moving things out into drivers instead.
 
 After Al Viro reviewed an earlier version of this series and did a lot
 more of that cleanup, I decided to try to completely eliminate the rest
 of it and move it all into drivers.
 
 This series incorporates some of Al's work and many patches of my own,
 but in the end stops short of actually removing the last part, which is
 the scsi ioctl handlers. I have patches for those as well, but they need
 more testing or possibly a rewrite.
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJdsHCdAAoJEJpsee/mABjZtYkP/1JGl3jFv3Iq/5BCdPkaePP1
 RtMJRNfURgK3GeuHUui330PvVjI/pLWXU/VXMK2MPTASpJLzYz3uCaZrpVWEMpDZ
 +ImzGmgJkITlW1uWU3zOcQhOxTyb1hCZ0Ci+2xn9QAmyOL7prXoXCXDWv3h6iyiF
 lwG+nW+HNtyx41YG+9bRfKNoG0ZJ+nkJ70BV6u0acQHXWn7Xuupa9YUmBL87hxAL
 6dlJfLTJg6q8QSv/Q6LxslfWk2Ti8OOJZOwtFM5R8Bgl0iUcvshiRCKfv/3t9jXD
 dJNvF1uq8z+gracWK49Qsfq5dnZ2ZxHFUo9u0NjbCrxNvWH/sdvhbaUBuJI75seH
 VIznCkdxFhrqitJJ8KmxANxG08u+9zSKjSlxG2SmlA4qFx/AoStoHwQXcogJscNb
 YIXYKmWBvwPzYu09QFAXdHFPmZvp/3HhMWU6o92lvDhsDwzkSGt3XKhCJea4DCaT
 m+oCcoACqSWhMwdbJOEFofSub4bY43s5iaYuKes+c8O261/Dwg6v/pgIVez9mxXm
 TBnvCsotq5m8wbwzv99eFqGeJH8zpDHrXxEtRR5KQqMqjLq/OQVaEzmpHZTEuK7n
 e/V/PAKo2/V63g4k6GApQXDxnjwT+m0aWToWoeEzPYXS6KmtWC91r4bWtslu3rdl
 bN65armTm7bFFR32Avnu
 =lgCl
 -----END PGP SIGNATURE-----

Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann:
 "As part of the cleanup of some remaining y2038 issues, I came to
  fs/compat_ioctl.c, which still has a couple of commands that need
  support for time64_t.

  In completely unrelated work, I spent time on cleaning up parts of
  this file in the past, moving things out into drivers instead.

  After Al Viro reviewed an earlier version of this series and did a lot
  more of that cleanup, I decided to try to completely eliminate the
  rest of it and move it all into drivers.

  This series incorporates some of Al's work and many patches of my own,
  but in the end stops short of actually removing the last part, which
  is the scsi ioctl handlers. I have patches for those as well, but they
  need more testing or possibly a rewrite"

* tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits)
  scsi: sd: enable compat ioctls for sed-opal
  pktcdvd: add compat_ioctl handler
  compat_ioctl: move SG_GET_REQUEST_TABLE handling
  compat_ioctl: ppp: move simple commands into ppp_generic.c
  compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t
  compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic
  compat_ioctl: unify copy-in of ppp filters
  tty: handle compat PPP ioctls
  compat_ioctl: move SIOCOUTQ out of compat_ioctl.c
  compat_ioctl: handle SIOCOUTQNSD
  af_unix: add compat_ioctl support
  compat_ioctl: reimplement SG_IO handling
  compat_ioctl: move WDIOC handling into wdt drivers
  fs: compat_ioctl: move FITRIM emulation into file systems
  gfs2: add compat_ioctl support
  compat_ioctl: remove unused convert_in_user macro
  compat_ioctl: remove last RAID handling code
  compat_ioctl: remove /dev/raw ioctl translation
  compat_ioctl: remove PCI ioctl translation
  compat_ioctl: remove joystick ioctl translation
  ...
2019-12-01 13:46:15 -08:00
David Sterba 8d6fac0087 btrfs: add support for 4-copy replication (raid1c4)
Add new block group profile to store 4 copies in a simliar way that
current RAID1 does.  The profile attributes and constraints are defined
in the raid table and used by the same code that already handles the 2-
and 3-copy RAID1.

The minimum number of devices is 4, the maximum number of devices/chunks
that can be lost/damaged is 3. There is no comparable traditional RAID
level, the profile is added for future needs to accompany triple-parity
and beyond.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:49 +01:00
David Sterba 47e6f7423b btrfs: add support for 3-copy replication (raid1c3)
Add new block group profile to store 3 copies in a simliar way that
current RAID1 does. The profile attributes and constraints are defined
in the raid table and used by the same code that already handles the
2-copy RAID1.

The minimum number of devices is 3, the maximum number of devices/chunks
that can be lost/damaged is 2. Like RAID6 but with 33% space
utilization.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:49 +01:00
Johannes Thumshirn f5389f330d btrfs: remove cached space_info in btrfs_statfs()
In btrfs_statfs() we cache fs_info::space_info in a local variable only
to use it once in a list_for_each_rcu() statement.

Not only is the local variable unnecessary it even makes the code harder
to follow as it's not clear which list it is iterating.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:45 +01:00
David Sterba 352ae07b59 btrfs: add blake2b to checksumming algorithms
Add blake2b (with 256 bit digest) to the list of possible checksumming
algorithms used by BTRFS.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:44 +01:00
Johannes Thumshirn 3831bf0094 btrfs: add sha256 to checksumming algorithm
Add sha256 to the list of possible checksumming algorithms used by BTRFS.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:43 +01:00
Johannes Thumshirn 3951e7f050 btrfs: add xxhash64 to checksumming algorithms
Add xxhash64 to the list of possible checksumming algorithms used by
BTRFS.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 17:51:43 +01:00
Chris Mason ba8a9d0795 Btrfs: delete the entire async bio submission framework
Now that we're not using btrfs_schedule_bio() anymore, delete all the
code that supported it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:53 +01:00
David Sterba 4143cb8b6f btrfs: add const function attribute
For some reason the attribute is called __attribute_const__ and not
__const, marks functions that have no observable effects on program
state, IOW not reading pointers, just the arguments and calculating a
value. Allows the compiler to do some optimizations, based on
-Wsuggest-attribute=const . The effects are rather small, though, about
60 bytes decrese of btrfs.ko.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:52 +01:00
David Sterba b105e92755 btrfs: add __cold attribute to more functions
The attribute can mark functions supposed to be called rarely if at all
and the text can be moved to sections far from the other code. The
attribute has been added to several functions already, this patch is
based on hints given by gcc -Wsuggest-attribute=cold.

The net effect of this patch is decrease of btrfs.ko by 1000-1300,
depending on the config options.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:52 +01:00
David Sterba 4c66e0d424 btrfs: drop unused parameter is_new from btrfs_iget
The parameter is now always set to NULL and could be dropped. The last
user was get_default_root but that got reworked in 05dbe6837b ("Btrfs:
unify subvol= and subvolid= mounting") and the parameter became unused.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:52 +01:00
Josef Bacik 6f0d04f8e7 btrfs: separate out the extent io init function
We are moving extent_io_tree into it's on file, so separate out the
extent_state init stuff from extent_io_tree_init().

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:47 +01:00
Arnd Bergmann 1832f2d8ff compat_ioctl: move more drivers to compat_ptr_ioctl
The .ioctl and .compat_ioctl file operations have the same prototype so
they can both point to the same function, which works great almost all
the time when all the commands are compatible.

One exception is the s390 architecture, where a compat pointer is only
31 bit wide, and converting it into a 64-bit pointer requires calling
compat_ptr(). Most drivers here will never run in s390, but since we now
have a generic helper for it, it's easy enough to use it consistently.

I double-checked all these drivers to ensure that all ioctl arguments
are used as pointers or are ignored, but are not interpreted as integer
values.

Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:44 +02:00
David Sterba 89439109bc btrfs: move sysfs declarations out of ctree.h
As the header for sysfs code already exists, use it to clean up ctree.h.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:06 +02:00
Josef Bacik aac0023c21 btrfs: move basic block_group definitions to their own header
This is prep work for moving all of the block group cache code into its
own file.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:03 +02:00
Nikolay Borisov 559ca6ea69 btrfs: Refactor btrfs_calc_avail_data_space
Simplify the code by removing variables that don't bring any real value
as well as simplifying the checks when buidling the candidate list of
devices. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:02 +02:00
Josef Bacik 8719aaae8d btrfs: move space_info to space-info.h
Migrate the struct definition and the one helper that's in ctree.h into
space-info.h

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba e1ea2beee2 btrfs: use raid_attr for minimum stripe count in btrfs_calc_avail_data_space
Minimum stripe count matches the minimum devices required for a given
profile. The open coded assignments match the raid_attr table.

What's changed here is the meaning for RAID5/6. Previously their
min_stripes would be 1, while newly it's devs_min. This however shold be
the same as before because it's not possible to create filesystem on
fewer devices than the raid_attr table allows.

There's no adjustment regarding the parity stripes (like
calc_data_stripes does), because we're interested in overall space that
would fit on the devices.

Missing devices make no difference for the whole calculation, we have
the size stored in the structures.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba 4f080f5711 btrfs: use raid_attr to adjust minimal stripe size in btrfs_calc_avail_data_space
Special case for DUP can be replaced by lookup to the attribute table,
where the dev_stripes is the right coefficient.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
Johannes Thumshirn d5178578bc btrfs: directly call into crypto framework for checksumming
Currently btrfs_csum_data() relied on the crc32c() wrapper around the
crypto framework for calculating the CRCs.

As we have our own crypto_shash structure in the fs_info now, we can
directly call into the crypto framework without going trough the wrapper.

This way we can even remove the btrfs_csum_data() and btrfs_csum_final()
wrappers.

The module dependency on crc32c is preserved via MODULE_SOFTDEP("pre:
crc32c"), which was previously provided by LIBCRC32C config option doing
the same.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Goldwyn Rodrigues cebf05ca65 btrfs: Remove unused variable mode in btrfs_mount
This is a leftover from 312c89fbca ("btrfs: cleanup btrfs_mount()
using btrfs_mount_root()"), the mode was used for opening devices that's
not done here anymore.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
David Sterba 9b4e675a99 btrfs: detect fast implementation of crc32c on all architectures
Currently, there's only check for fast crc32c implementation on X86,
based on the CPU flags. This is used to decide if checksumming should be
offloaded to worker threads or can be calculated by the caller.

As there are more architectures that implement a faster version of
crc32c (ARM, SPARC, s390, MIPS, PowerPC), also there are specialized hw
cards.

The detection is based on driver name, all generic C implementations
contain 'generic', while the specialized versions do not. Alternatively
the priority could be used, but this is not currently provided by the
crypto API.

The flag is set per-filesystem at mount time and used for the offloading
decisions.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
Linus Torvalds 9f2e3a53f7 for-5.2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAlzQM7MACgkQxWXV+ddt
 WDvrVw/+K0AElSuEfDFWd9HBqRAPlGaEP71xCGGle1tkzuY0DJVIBRZ72q8UR0YP
 7yke7DU0oqXekGype83eTJUjDSLoOXrlVoQ+VqBdFteDk0W4BCG6Nw+N+wYBF7An
 gXRXlGFaYzb2CqqjG92FbtkfxBzISR0XBCQBUN9CBqHNDu1EUQSbnTBkmTMN8MYh
 PCoo37S6e5fR36uB/rOKbGNBJjsZEEg/2G6DprP52+eiQWV2h0avEUJrvv6xC4so
 97QNgUNuuiUmyurqcYHdlaflZwIhuf5nQeNeu/UvMZmmRnBHPhSP7YPM7f7FftwA
 y0d0p+AiEAO0he8nGFb5C6Avs4vuv1u65o1NbF5fqnmAyt+KXWem3LeG6etsXgU8
 +eITgprJD3sNBMDLbLoA+wlhTps+w9tukVF5Zp2a8KgQLMMEyAYqUDWmSHvnO2Me
 RCNPZLzeGXETgKun0WuMtl/CX2iBDnc0Kq5O6ks2ORl2TH6bg5lgEIwr6HP/Ewoy
 w8twsmCOltrxiIptqyQHYD+kvNwqMVV9LSOQ8+EjbYd6BHsfjHjKObOBkhmJ7iqz
 4MAIcZU++F9DLRv92H1kUYVNhAMCdXkEIWyxhZPwN1lUi5k9AhknY3FbheNc7ldl
 LNPIgRxamWCq9oBmzfOcJ3eFOBtNN02fgA1GTXGd1/AgAilEep8=
 =fEkD
 -----END PGP SIGNATURE-----

Merge tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This time the majority of changes are cleanups, though there's still a
  number of changes of user interest.

  User visible changes:

   - better read time and write checks to catch errors early and before
     writing data to disk (to catch potential memory corruption on data
     that get checksummed)

   - qgroups + metadata relocation: last speed up patch int the series
     to address the slowness, there should be no overhead comparing
     balance with and without qgroups

   - FIEMAP ioctl does not start a transaction unnecessarily, this can
     result in a speed up and less blocking due to IO

   - LOGICAL_INO (v1, v2) does not start transaction unnecessarily, this
     can speed up the mentioned ioctl and scrub as well

   - fsync on files with many (but not too many) hardlinks is faster,
     finer decision if the links should be fsynced individually or
     completely

   - send tries harder to find ranges to clone

   - trim/discard will skip unallocated chunks that haven't been touched
     since the last mount

  Fixes:

   - send flushes delayed allocation before start, otherwise it could
     miss some changes in case of a very recent rw->ro switch of a
     subvolume

   - fix fallocate with qgroups that could lead to space accounting
     underflow, reported as a warning

   - trim/discard ioctl honours the requested range

   - starting send and dedupe on a subvolume at the same time will let
     only one of them succeed, this is to prevent changes that send
     could miss due to dedupe; both operations are restartable

  Core changes:

   - more tree-checker validations, errors reported by fuzzing tools:
      - device item
      - inode item
      - block group profiles

   - tracepoints for extent buffer locking

   - async cow preallocates memory to avoid errors happening too deep in
     the call chain

   - metadata reservations for delalloc reworked to better adapt in
     many-writers/low-space scenarios

   - improved space flushing logic for intense DIO vs buffered workloads

   - lots of cleanups
      - removed unused struct members
      - redundant argument removal
      - properties and xattrs
      - extent buffer locking
      - selftests
      - use common file type conversions
      - many-argument functions reduction"

* tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (227 commits)
  btrfs: Use kvmalloc for allocating compressed path context
  btrfs: Factor out common extent locking code in submit_compressed_extents
  btrfs: Set io_tree only once in submit_compressed_extents
  btrfs: Replace clear_extent_bit with unlock_extent
  btrfs: Make compress_file_range take only struct async_chunk
  btrfs: Remove fs_info from struct async_chunk
  btrfs: Rename async_cow to async_chunk
  btrfs: Preallocate chunks in cow_file_range_async
  btrfs: reserve delalloc metadata differently
  btrfs: track DIO bytes in flight
  btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
  btrfs: delete unused function btrfs_set_prop_trans
  btrfs: start transaction in xattr_handler_set_prop
  btrfs: drop local copy of inode i_mode
  btrfs: drop old_fsflags in btrfs_ioctl_setflags
  btrfs: modify local copy of btrfs_inode flags
  btrfs: drop useless inode i_flags copy and restore
  btrfs: start transaction in btrfs_ioctl_setflags()
  btrfs: export btrfs_set_prop
  btrfs: refactor btrfs_set_props to validate externally
  ...
2019-05-07 11:34:19 -07:00
Al Viro 26602cab41 btrfs: use ->free_inode()
a lot of stuff remains in ->destroy_inode()

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:26 -04:00
Anand Jain ae0bc86310 btrfs: drop unused parameter in mount_subvol
@device_name in mount_subvol() is not used, drop it.  Also see:
5bedc48a8f ("btrfs: drop unused parameters from mount_subvol").

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:35 +02:00
Dennis Zhou 3f93aef535 btrfs: add zstd compression level support
Zstd compression requires different amounts of memory for each level of
compression. The prior patches implemented indirection to allow for each
compression type to manage their workspaces independently. This patch
uses this indirection to implement compression level support for zstd.

To manage the additional memory require, each compression level has its
own queue of workspaces. A global LRU is used to help with reclaim.
Reclaim is done via a timer which provides a mechanism to decrease
memory utilization by keeping only workspaces around that are sized
appropriately. Forward progress is guaranteed by a preallocated max
workspace hidden from the LRU.

When getting a workspace, it uses a bitmap to identify the levels that
are populated and scans up. If it finds a workspace that is greater than
it, it uses it, but does not update the last_used time and the
corresponding place in the LRU. If we hit memory pressure, we sleep on
the max level workspace. We continue to rescan in case we can use a
smaller workspace, but eventually should be able to obtain the max level
workspace or allocate one again should memory pressure subside.

The memory requirement for decompression is the same as level 1, and
therefore can use any of available workspace.

The number of workspaces is bound by an upper limit of the workqueue's
limit which currently is 2 (percpu limit). The reclaim timer is used to
free inactive/improperly sized workspaces and is set to 307s to avoid
colliding with transaction commit (every 30s).

Repeating the experiment from v2 [1], the Silesia corpus was copied to a
btrfs filesystem 10 times and then read back after dropping the caches.
The btrfs filesystem was on an SSD.

Level   Ratio   Compression (MB/s)  Decompression (MB/s)  Memory (KB)
1       2.658        438.47                910.51            780
2       2.744        364.86                886.55           1004
3       2.801        336.33                828.41           1260
4       2.858        286.71                886.55           1260
5       2.916        212.77                556.84           1388
6       2.363        119.82                990.85           1516
7       3.000        154.06                849.30           1516
8       3.011        159.54                875.03           1772
9       3.025        100.51                940.15           1772
10      3.033        118.97                616.26           1772
11      3.036         94.19                802.11           1772
12      3.037         73.45                931.49           1772
13      3.041         55.17                835.26           2284
14      3.087         44.70                716.78           2547
15      3.126         37.30                878.84           2547

[1] https://lore.kernel.org/linux-btrfs/20181031181108.289340-1-terrelln@fb.com/

Cc: Nick Terrell <terrelln@fb.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou d0ab62ce2d btrfs: change set_level() to bound the level passed in
Currently, the only user of set_level() is zlib which sets an internal
workspace parameter. As level is now plumbed into get_workspace(), this
can be handled there rather than separately.

This repurposes set_level() to bound the level passed in so it can be
used when setting the mounts compression level and as well as verifying
the level before getting a workspace. The other benefit is this divides
the meaning of compress(0) and get_workspace(0). The former means we
want to use the default compression level of the compression type. The
latter means we can use any workspace available.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Anand Jain 228a73abde btrfs: introduce new ioctl to unregister a btrfs device
Support for a new command that can be used eg. as a command

  $ btrfs device scan --forget [dev]'
(the final name may change though)

to undo the effects of 'btrfs device scan [dev]'. For this purpose
this patch proposes to use ioctl #5 as it was empty and is next to the
SCAN ioctl.

The new ioctl BTRFS_IOC_FORGET_DEV works only on the control device
(/dev/btrfs-control) to unregister one or all devices, devices that are
not mounted.

The argument is struct btrfs_ioctl_vol_args, ::name specifies the device
path. To unregister all device, the path is an empty string.

Again, the devices are removed only if they aren't part of a mounte
filesystem.

This new ioctl provides:

- release of unwanted btrfs_fs_devices and btrfs_devices structures
  from memory if the device is not going to be mounted

- ability to mount filesystem in degraded mode, when one devices is
  corrupted like in split brain raid1

- running test cases which would require reloading the kernel module
  but this is not possible eg. due to mounted filesystem or built-in

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Linus Torvalds 312b3a93dd for-5.0-rc4-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAlxWtJgACgkQxWXV+ddt
 WDsDow//ZpnyDwQWvSIfF2UUQOPlcBjbHKuBA7rU0wdybW635QYGR0mqnI+1VnMj
 7ssUkeN6N0a2gQzrUG4Y+zpdzOWv2xQ4jKZ9GMOp9gwyzEFyPkcFXOnmM8UfYtVu
 e3fK65e8BZHmTeu0kGKah4Dt1g0t4fUmhsKR4Pfp5YNJC+zuuGTwUW1K/ZQHXJ+3
 kTHc7WP1lsF7wgaZ+Gl+Kvp8fVrHVdygMVTdRBW8QaBgPLa/KExvK62jW+NmCYhj
 7OIkWdew7e8IXc3Ie5IbOomHAv7IgqqgiO9VO9+n0EpyV4UobUgxrgBKJ+0yc1Ya
 eidbKhMslwUE50y00JVm+vw0gwQHkR+hZDn/mRB6xiIeI8tu/yQIJZ6AhYJXoByR
 cu8+SNO5Z5dOZ1f146ZH8lnkr24tuSnkDUhbRDR5pdb4tAHHej2ALzhbfbwbPEpF
 IverYLw5fOMGeRU/mBsjkVadpSZ4S0HVNU85ERdhLtVLK1PSaY2UkUaA+Ii5y7au
 EYDjaGMflmJ8cAVqgtgedEff2n8OKDnzRZlz4IPLI73MVSITGZkM7PmYmYsLm2Bs
 mDPnmyqR8kzcd1RRtSeZTvqOpAIZG+QUOmD2jiKrchmp54Sz0V/HJWRs3aQybD6Q
 ph0yAcbkvgp/ewe5IFgaI0kcyH7zYdL6GtiI2WUE3/8DObgrgsA=
 =E2PP
 -----END PGP SIGNATURE-----

Merge tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression fix: transaction commit can run away due to delayed ref
   waiting heuristic, this is not necessary now because of the proper
   reservation mechanism introduced in 5.0

 - regression fix: potential crash due to use-before-check of an ERR_PTR
   return value

 - fix for transaction abort during transaction commit that needs to
   properly clean up pending block groups

 - fix deadlock during b-tree node/leaf splitting, when this happens on
   some of the fundamental trees, we must prevent new tree block
   allocation to re-enter indirectly via the block group flushing path

 - potential memory leak after errors during mount

* tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: On error always free subvol_name in btrfs_mount
  btrfs: clean up pending block groups when transaction commit aborts
  btrfs: fix potential oops in device_list_add
  btrfs: don't end the transaction for delayed refs in throttle
  Btrfs: fix deadlock when allocating tree block during leaf/node split
2019-02-03 08:48:33 -08:00
Eric W. Biederman 532b618bdf btrfs: On error always free subvol_name in btrfs_mount
The subvol_name is allocated in btrfs_parse_subvol_options and is
consumed and freed in mount_subvol.  Add a free to the error paths that
don't call mount_subvol so that it is guaranteed that subvol_name is
freed when an error happens.

Fixes: 312c89fbca ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()")
Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:47 +01:00
Linus Torvalds 505b050fdf Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...
2019-01-05 13:25:58 -08:00
Al Viro 204cc0ccf1 LSM: hide struct security_mnt_opts from any generic code
Keep void * instead, allocate on demand (in parse_str_opts, at the
moment).  Eventually both selinux and smack will be better off
with private structures with several strings in those, rather than
this "counter and two pointers to dynamically allocated arrays"
ugliness.  This commit allows to do that at leisure, without
disrupting anything outside of given module.

Changes:
	* instead of struct security_mnt_opt use an opaque pointer
initialized to NULL.
	* security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and
security_free_mnt_opts() take it as var argument (i.e. as void **);
call sites are unchanged.
	* security_sb_set_mnt_opts() and security_sb_remount() take
it by value (i.e. as void *).
	* new method: ->sb_free_mnt_opts().  Takes void *, does
whatever freeing that needs to be done.
	* ->sb_set_mnt_opts() and ->sb_remount() might get NULL as
mnt_opts argument, meaning "empty".

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:48:34 -05:00
Al Viro a65001e8a4 btrfs: sanitize security_mnt_opts use
1) keeping a copy in btrfs_fs_info is completely pointless - we never
use it for anything.  Getting rid of that allows for simpler calling
conventions for setup_security_options() (caller is responsible for
freeing mnt_opts in all cases).

2) on remount we want to use ->sb_remount(), not ->sb_set_mnt_opts(),
same as we would if not for FS_BINARY_MOUNTDATA.  Behaviours *are*
close (in fact, selinux sb_set_mnt_opts() ought to punt to
sb_remount() in "already initialized" case), but let's handle
that uniformly.  And the only reason why the original btrfs changes
didn't go for security_sb_remount() in btrfs_remount() case is that
it hadn't been exported.  Let's export it for a while - it'll be
going away soon anyway.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:47:08 -05:00
Al Viro f5c0c26d90 new helper: security_sb_eat_lsm_opts()
combination of alloc_secdata(), security_sb_copy_data(),
security_sb_parse_opt_str() and free_secdata().

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:46:00 -05:00
Andrea Gelmini 52042d8e82 btrfs: Fix typos in comments and strings
The typos accumulate over time so once in a while time they get fixed in
a large patch.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:50 +01:00
Nikolay Borisov de37aa5131 btrfs: Remove fsid/metadata_fsid fields from btrfs_info
Currently btrfs_fs_info structure contains a copy of the
fsid/metadata_uuid fields. Same values are also contained in the
btrfs_fs_devices structure which fs_info has a reference to. Let's
reduce duplication by removing the fields from fs_info and always refer
to the ones in fs_devices. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:37 +01:00
Filipe Manana f505754fd6 Btrfs: ensure path name is null terminated at btrfs_control_ioctl
We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel.  The ioctl is protected by CAP_SYS_ADMIN.

So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-14 18:26:20 +01:00
Arnd Bergmann 7e17916b35 btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
Note: this patch fixes a problem in a feature outside of btrfs ("kernel
hacking: add a config option to disable compiler auto-inlining") and is
applied ahead of time due to cross-subsystem dependencies.

On 32-bit ARM with gcc-8, I see a link error with the addition of the
CONFIG_NO_AUTO_INLINE option:

fs/btrfs/super.o: In function `btrfs_statfs':
super.c:(.text+0x67b8): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x67fc): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6858): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6920): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x693c): undefined reference to `__aeabi_uldivmod'
fs/btrfs/super.o:super.c:(.text+0x6958): more undefined references to `__aeabi_uldivmod' follow

So far this is the only file that shows the behavior, so I'd propose
to just work around it by marking the functions as 'static inline'
that normally get inlined here.

The reference to __aeabi_uldivmod comes from a div_u64() which has an
optimization for a constant division that uses a straight '/' operator
when the result should be known to the compiler. My interpretation is
that as we turn off inlining, gcc still expects the result to be constant
but fails to use that constant value.

Link: https://lkml.kernel.org/r/20181103153941.1881966-1-arnd@arndb.de
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ add the note ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:42:08 +01:00
Misono Tomohiro 4fd786e6c3 btrfs: Remove 'objectid' member from struct btrfs_root
There are two members in struct btrfs_root which indicate root's
objectid: objectid and root_key.objectid.

They are both set to the same value in __setup_root():

  static void __setup_root(struct btrfs_root *root,
                           struct btrfs_fs_info *fs_info,
                           u64 objectid)
  {
    ...
    root->objectid = objectid;
    ...
    root->root_key.objectid = objecitd;
    ...
  }

and not changed to other value after initialization.

grep in btrfs directory shows both are used in many places:
  $ grep -rI "root->root_key.objectid" | wc -l
  133
  $ grep -rI "root->objectid" | wc -l
  55
 (4.17, inc. some noise)

It is confusing to have two similar variable names and it seems
that there is no rule about which should be used in a certain case.

Since ->root_key itself is needed for tree reloc tree, let's remove
'objecitd' member and unify code to use ->root_key.objectid in all places.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:25 +02:00
Misono Tomohiro 672d599041 btrfs: Use wrapper macro for rcu string to remove duplicate code
Cleanup patch and no functional changes.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:13:02 +02:00
Josef Bacik 3c4276936f Btrfs: fix btrfs_write_inode vs delayed iput deadlock
We recently ran into the following deadlock involving
btrfs_write_inode():

[  +0.005066]  __schedule+0x38e/0x8c0
[  +0.007144]  schedule+0x36/0x80
[  +0.006447]  bit_wait+0x11/0x60
[  +0.006446]  __wait_on_bit+0xbe/0x110
[  +0.007487]  ? bit_wait_io+0x60/0x60
[  +0.007319]  __inode_wait_for_writeback+0x96/0xc0
[  +0.009568]  ? autoremove_wake_function+0x40/0x40
[  +0.009565]  inode_wait_for_writeback+0x21/0x30
[  +0.009224]  evict+0xb0/0x190
[  +0.006099]  iput+0x1a8/0x210
[  +0.006103]  btrfs_run_delayed_iputs+0x73/0xc0
[  +0.009047]  btrfs_commit_transaction+0x799/0x8c0
[  +0.009567]  btrfs_write_inode+0x81/0xb0
[  +0.008008]  __writeback_single_inode+0x267/0x320
[  +0.009569]  writeback_sb_inodes+0x25b/0x4e0
[  +0.008702]  wb_writeback+0x102/0x2d0
[  +0.007487]  wb_workfn+0xa4/0x310
[  +0.006794]  ? wb_workfn+0xa4/0x310
[  +0.007143]  process_one_work+0x150/0x410
[  +0.008179]  worker_thread+0x6d/0x520
[  +0.007490]  kthread+0x12c/0x160
[  +0.006620]  ? put_pwq_unlocked+0x80/0x80
[  +0.008185]  ? kthread_park+0xa0/0xa0
[  +0.007484]  ? do_syscall_64+0x53/0x150
[  +0.007837]  ret_from_fork+0x29/0x40

Writeback calls:

btrfs_write_inode
  btrfs_commit_transaction
    btrfs_run_delayed_iputs

If iput() is called on that same inode, evict() will wait for writeback
forever.

btrfs_write_inode() was originally added way back in 4730a4bc5b
("btrfs_dirty_inode") to support O_SYNC writes. However, ->write_inode()
hasn't been used for O_SYNC since 148f948ba8 ("vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode"), so
btrfs_write_inode() is actually unnecessary (and leads to a bunch of
unnecessary commits). Get rid of it, which also gets rid of the
deadlock.

CC: stable@vger.kernel.org # 3.2+
Signed-off-by: Josef Bacik <jbacik@fb.com>
[Omar: new commit message]
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:58 +02:00
David Sterba 46df06b85e btrfs: refactor block group replication factor calculation to a helper
There are many places that open code the duplicity factor of the block
group profiles, create a common helper. This can be easily extended for
more copies.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:53 +02:00
Anand Jain fa59f27c8c btrfs: rename btrfs_parse_early_options
Rename btrfs_parse_early_options() to btrfs_parse_device_options(). As
btrfs_parse_early_options() parses the -o device options and scan the
device provided. So this rename specifies its action. Also the function
name is in line with btrfs_parse_subvol_options().
No functional changes.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:49 +02:00
Gu Jinxiang 36350e95a2 btrfs: return device pointer from btrfs_scan_one_device
Return device pointer (with the IS_ERR semantics) from
btrfs_scan_one_device so we don't have to return in through pointer.

And since btrfs_fs_devices can be obtained from btrfs_device, return that.

Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ fixed conflics after recent changes to btrfs_scan_one_device ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:48 +02:00
Gu Jinxiang d64dcbd183 btrfs: make fs_devices a local variable in btrfs_parse_early_options
fs_devices is always passed to btrfs_scan_one_device which overrides it.
In the call stack below fs_devices is passed to btrfs_scan_one_device
from btrfs_mount_root.  In btrfs_mount_root the output fs_devices of
this call stack is not used.

btrfs_mount_root
  btrfs_parse_early_options
    btrfs_scan_one_device

So, it is not necessary to pass fs_devices from btrfs_mount_root, using
a local variable in btrfs_parse_early_options is enough.

Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:48 +02:00
David Sterba 81ffd56b57 btrfs: fix mount and ioctl device scan ioctl race
Technically this extends the critical section covered by uuid_mutex to:

- parse early mount options -- here we can call device scan on paths
  that can be passed as 'device=/dev/...'

- scan the device passed to mount

- open the devices related to the fs_devices -- this increases
  fs_devices::opened

The race can happen when mount calls one of the scans and there's
another one called eg. by mkfs or 'btrfs dev scan':

Mount                                  Scan
-----                                  ----
scan_one_device (dev1, fsid1)
                                       scan_one_device (dev2, fsid1)
				           add the device
					   free stale devices
					       fsid1 fs_devices::opened == 0
					           find fsid1:dev1
					           free fsid1:dev1
					           if it's the last one,
					            free fs_devices of fsid1
						    too

open_devices (dev1, fsid1)
   dev1 not found

When fixed, the uuid mutex will make sure that mount will increase
fs_devices::opened and this will not be touched by the racing scan
ioctl.

Reported-and-tested-by: syzbot+909a5177749d7990ffa4@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+ceb2606025ec1cc3479c@syzkaller.appspotmail.com
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:48 +02:00