linux-stable.git/fs/btrfs, branch v6.3.2

btrfs: scrub: reject unsupported scrub flags

2023-05-11T14:17:37+00:00

commit 604e6681e114d05a2e384c4d1e8ef81918037ef5 upstream.

Since the introduction of scrub interface, the only flag that we support
is BTRFS_SCRUB_READONLY.  Thus there is no sanity checks, if there are
some undefined flags passed in, we just ignore them.

This is problematic if we want to introduce new scrub flags, as we have
no way to determine if such flags are supported.

Address the problem by introducing a check for the flags, and if
unsupported flags are set, return -EOPNOTSUPP to inform the user space.

This check should be backported for all supported kernels before any new
scrub flags are introduced.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix uninitialized variable warnings

2023-04-30T23:32:26+00:00

commit 8ba7d5f5ba931be68a94b8c91bcced1622934e7a upstream.

There are some warnings on older compilers (gcc 10, 7) or non-x86_64
architectures (aarch64).  As btrfs wants to enable -Wmaybe-uninitialized
by default, fix the warnings even though it's not necessary on recent
compilers (gcc 12+).

../fs/btrfs/volumes.c: In function ‘btrfs_init_new_device’:
../fs/btrfs/volumes.c:2703:3: error: ‘seed_devices’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
 2703 |   btrfs_setup_sprout(fs_info, seed_devices);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

../fs/btrfs/send.c: In function ‘get_cur_inode_state’:
../include/linux/compiler.h:70:32: error: ‘right_gen’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
   70 |   (__if_trace.miss_hit[1]++,1) :  \
      |                                ^
../fs/btrfs/send.c:1878:6: note: ‘right_gen’ was declared here
 1878 |  u64 right_gen;
      |      ^~~~~~~~~

Reported-by: k2ci 
Signed-off-by: Genjian Zhang 
Reviewed-by: David Sterba 
[ update changelog ]
Signed-off-by: David Sterba 
Cc: Ammar Faizi 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2023-04-21T17:47:21+00:00

Pull btrfs fixes from David Sterba:
 "Two patches fixing the problem with aync discard.

  The default settings had a low IOPS limit and processing a large batch
  to discard would take a long time. On laptops this can cause increased
  power consumption due to disk activity.

  As async discard has been on by default since 6.2 this likely affects
  a lot of users.

  Summary:

   - increase the default IOPS limit 10x which reportedly helped

   - setting the sysfs IOPS value to 0 now does not throttle anymore
     allowing the discards to be processed at full speed. Previously
     there was an arbitrary 6 hour target for processing the pending
     batch"

* tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: reinterpret async discard iops_limit=0 as no delay
  btrfs: set default discard iops_limit to 1000

btrfs: reinterpret async discard iops_limit=0 as no delay

2023-04-20T22:28:23+00:00

Currently, a limit of 0 results in a hard coded metering over 6 hours.
Since the default is a set limit, I suspect no one truly depends on this
rather arbitrary setting. Repurpose it for an arguably more useful
"unlimited" mode, where the delay is 0.

Note that if block groups are too new, or go fully empty, there is still
a delay associated with those conditions. Those delays implement
heuristics for not trimming a region we are relatively likely to fully
overwrite soon.

CC: stable@vger.kernel.org # 6.2+
Reviewed-by: Neal Gompa 
Signed-off-by: Boris Burkov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: set default discard iops_limit to 1000

2023-04-20T22:28:20+00:00

Previously, the default was a relatively conservative 10. This results
in a 100ms delay, so with ~300 discards in a commit, it takes the full
30s till the next commit to finish the discards. On a workstation, this
results in the disk never going idle, wasting power/battery, etc.

Set the default to 1000, which results in using the smallest possible
delay, currently, which is 1ms. This has shown to not pathologically
keep the disk busy by the original reporter.

Link: https://lore.kernel.org/linux-btrfs/Y%2F+n1wS%2F4XAH7X1p@nz/
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2182228
CC: stable@vger.kernel.org # 6.2+
Reviewed-by: Neal Gompa 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

Merge tag 'for-6.3-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2023-04-11T18:43:16+00:00

Pull btrfs fixes from David Sterba:

 - fix fast checksum detection, this affects filesystems with non-crc32c
   checksum, calculation would not be offloaded to worker threads

 - restore thread_pool mount option behaviour for endio workers, the new
   value for maximum active threads would not be set to the actual work
   queues

* tag 'for-6.3-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix fast csum implementation detection
  btrfs: restore the thread_pool= behavior in remount for the end I/O workqueues

btrfs: fix fast csum implementation detection

2023-04-06T14:34:13+00:00

The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic
crc32c is detected, which is the incorrect check if the file system uses
a different checksumming algorithm.  Refactor the code to only check
this if crc32c is actually used.  Note that in an ideal world the
information if an algorithm is hardware accelerated or not should be
provided by the crypto API instead, but that's left for another day.

CC: stable@vger.kernel.org # 5.4.x: c8a5f8ca9a9c: btrfs: print checksum type and implementation at mount time
CC: stable@vger.kernel.org # 5.4.x
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: restore the thread_pool= behavior in remount for the end I/O workqueues

2023-04-06T14:33:08+00:00

Commit d7b9416fe5c5 ("btrfs: remove btrfs_end_io_wq") converted the read
and I/O handling from btrfs_workqueues to Linux workqueues, and as part
of that lost the code to apply the thread_pool= based max_active limit
on remount.  Restore it.

Fixes: d7b9416fe5c5 ("btrfs: remove btrfs_end_io_wq")
CC: stable@vger.kernel.org # 6.0+
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

Merge tag 'for-6.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2023-04-02T17:57:12+00:00

Pull btrfs fixes from David Sterba:

 - scan block devices in non-exclusive mode to avoid temporary mkfs
   failures

 - fix race between quota disable and quota assign ioctls

 - fix deadlock when aborting transaction during relocation with scrub

 - ignore fiemap path cache when there are multiple paths for a node

* tag 'for-6.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: ignore fiemap path cache when there are multiple paths for a node
  btrfs: fix deadlock when aborting transaction during relocation with scrub
  btrfs: scan device in non-exclusive mode
  btrfs: fix race between quota disable and quota assign ioctls

btrfs: ignore fiemap path cache when there are multiple paths for a node

2023-03-28T23:16:23+00:00

During fiemap, when walking backreferences to determine if a b+tree
node/leaf is shared, we may find a tree block (leaf or node) for which
two parents were added to the references ulist. This happens if we get
for example one direct ref (shared tree block ref) and one indirect ref
(non-shared tree block ref) for the tree block at the current level,
which can happen during relocation.

In that case the fiemap path cache can not be used since it's meant for
a single path, with one tree block at each possible level, so having
multiple references for a tree block at any level may result in getting
the level counter exceed BTRFS_MAX_LEVEL and eventually trigger the
warning:

   WARN_ON_ONCE(level >= BTRFS_MAX_LEVEL)

at lookup_backref_shared_cache() and at store_backref_shared_cache().
This is harmless since the code ignores any level >= BTRFS_MAX_LEVEL, the
warning is there just to catch any unexpected case like the one described
above. However if a user finds this it may be scary and get reported.

So just ignore the path cache once we find a tree block for which there
are more than one reference, which is the less common case, and update
the cache with the sharedness check result for all levels below the level
for which we found multiple references.

Reported-by: Jarno Pelkonen 
Link: https://lore.kernel.org/linux-btrfs/CAKv8qLmDNAGJGCtsevxx_VZ_YOvvs1L83iEJkTgyA4joJertng@mail.gmail.com/
Fixes: 12a824dc67a6 ("btrfs: speedup checking for extent sharedness during fiemap")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba