linux-stable.git/fs/jbd2, branch linux-6.14.y

jbd2: Avoid long replay times due to high number or revoke blocks

2025-05-29T09:13:24+00:00

[ Upstream commit a399af4e3b1ab2c5d83292d4487c4d18de551659 ]

Some users are reporting journal replay takes a long time when there is
excessive number of revoke blocks in the journal. Reported times are
like:

1048576 records - 95 seconds
2097152 records - 580 seconds

The problem is that hash chains in the revoke table gets excessively
long in these cases. Fix the problem by sizing the revoke table
appropriately before the revoke pass.

Thanks to Alexey Zhuravlev  for benchmarking the
patch with large numbers of revoke blocks [1].

[1] https://lore.kernel.org/all/20250113183107.7bfef7b6@x390.bzzz77.ru

Signed-off-by: Jan Kara 
Reviewed-by: Andreas Dilger 
Reviewed-by: Zhang Yi 
Link: https://patch.msgid.link/20250121140925.17231-2-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: do not try to recover wiped journal

2025-05-29T09:12:39+00:00

[ Upstream commit a662f3c03b754e1f97a2781fa242e95bdb139798 ]

If a journal is wiped, we will set journal->j_tail to 0. However if
'write' argument is not set (as it happens for read-only device or for
ocfs2), the on-disk superblock is not updated accordingly and thus
jbd2_journal_recover() cat try to recover the wiped journal. Fix the
check in jbd2_journal_recover() to use journal->j_tail for checking
empty journal instead.

Signed-off-by: Jan Kara 
Reviewed-by: Zhang Yi 
Link: https://patch.msgid.link/20250206094657.20865-4-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

fs/jbd2: use sleeping version of __find_get_block()

2025-05-29T09:12:20+00:00

[ Upstream commit f76d4c28a46a9260d85e00dafc8f46d369365d33 ]

Convert to the new nonatomic flavor to benefit from potential
performance benefits and adapt in the future vs migration such
that semantics are kept.

- jbd2_journal_revoke(): can sleep (has might_sleep() in the beginning)

- jbd2_journal_cancel_revoke(): only used from do_get_write_access() and
    do_get_create_access() which do sleep. So can sleep.

- jbd2_clear_buffer_revoked_flags() - only called from journal commit code
    which sleeps. So can sleep.

Suggested-by: Jan Kara 
Reviewed-by: Jan Kara 
Signed-off-by: Davidlohr Bueso 
Link: https://kdevops.org/ext4/v6.15-rc2.html # [0]
Link: https://lore.kernel.org/all/aAAEvcrmREWa1SKF@bombadil.infradead.org/ # [1]
Link: https://lore.kernel.org/20250418015921.132400-6-dave@stgolabs.net
Tested-by: kdevops@lists.linux.dev
Reviewed-by: Luis Chamberlain 
Signed-off-by: Christian Brauner 
Signed-off-by: Sasha Levin

jbd2: remove wrong sb->s_sequence check

2025-04-20T08:23:02+00:00

commit e6eff39dd0fe4190c6146069cc16d160e71d1148 upstream.

Journal emptiness is not determined by sb->s_sequence == 0 but rather by
sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a
valid transaction ID so the check can spuriously trigger. Remove the
invalid WARN_ON.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Reviewed-by: Zhang Yi 
Link: https://patch.msgid.link/20250206094657.20865-3-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

jbd2: add a missing data flush during file and fs synchronization

2025-04-10T12:44:11+00:00

[ Upstream commit aac45075f6d79a63ac8dff93b3e1d7053a6ba628 ]

When the filesystem performs file or filesystem synchronization (e.g.,
ext4_sync_file()), it queries the journal to determine whether to flush
the file device through jbd2_trans_will_send_data_barrier(). If the
target transaction has not started committing, it assumes that the
journal will submit the flush command, allowing the filesystem to bypass
a redundant flush command. However, this assumption is not always valid.
If the journal is not located on the filesystem device, the journal
commit thread will not submit the flush command unless the variable
->t_need_data_flush is set to 1. Consequently, the flush may be missed,
and data may be lost following a power failure or system crash, even if
the synchronization appears to succeed.

Unfortunately, we cannot determine with certainty whether the target
transaction will flush to the filesystem device before it commits.
However, if it has not started committing, it must be the running
transaction. Therefore, fix it by always set its t_need_data_flush to 1,
ensuring that the committing thread will flush the filesystem device.

Fixes: bbd2be369107 ("jbd2: Add function jbd2_trans_will_send_data_barrier()")
Signed-off-by: Zhang Yi 
Reviewed-by: Jan Kara 
Link: https://patch.msgid.link/20241206111327.4171337-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

jbd2: fix off-by-one while erasing journal

2025-04-10T12:44:09+00:00

[ Upstream commit 18aba2adb3e2a676fff0d81e51f5045f3c636666 ]

In __jbd2_journal_erase(), the block_stop parameter includes the last
block of a contiguous region; however, the calculation of byte_stop is
incorrect, as it does not account for the bytes in that last block.
Consequently, the page cache is not cleared properly, which occasionally
causes the ext4/050 test to fail.

Since block_stop operates on inclusion semantics, it involves repeated
increments and decrements by 1, significantly increasing the complexity
of the calculations. Optimize the calculation and fix the incorrect
byte_stop by make both block_stop and byte_stop to use exclusion
semantics.

This fixes a failure in fstests ext4/050.

Fixes: 01d5d96542fd ("ext4: add discard/zeroout flags to journal flush")
Signed-off-by: Zhang Yi 
Reviewed-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://patch.msgid.link/20250217065955.3829229-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

2025-01-23T03:55:08+00:00

Pull CRC updates from Eric Biggers:

 - Reorganize the architecture-optimized CRC32 and CRC-T10DIF code to be
   directly accessible via the library API, instead of requiring the
   crypto API. This is much simpler and more efficient.

 - Convert some users such as ext4 to use the CRC32 library API instead
   of the crypto API. More conversions like this will come later.

 - Add a KUnit test that tests and benchmarks multiple CRC variants.
   Remove older, less-comprehensive tests that are made redundant by
   this.

 - Add an entry to MAINTAINERS for the kernel's CRC library code. I'm
   volunteering to maintain it. I have additional cleanups and
   optimizations planned for future cycles.

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (31 commits)
  MAINTAINERS: add entry for CRC library
  powerpc/crc: delete obsolete crc-vpmsum_test.c
  lib/crc32test: delete obsolete crc32test.c
  lib/crc16_kunit: delete obsolete crc16_kunit.c
  lib/crc_kunit.c: add KUnit test suite for CRC library functions
  powerpc/crc-t10dif: expose CRC-T10DIF function through lib
  arm64/crc-t10dif: expose CRC-T10DIF function through lib
  arm/crc-t10dif: expose CRC-T10DIF function through lib
  x86/crc-t10dif: expose CRC-T10DIF function through lib
  crypto: crct10dif - expose arch-optimized lib function
  lib/crc-t10dif: add support for arch overrides
  lib/crc-t10dif: stop wrapping the crypto API
  scsi: target: iscsi: switch to using the crc32c library
  f2fs: switch to using the crc32 library
  jbd2: switch to using the crc32c library
  ext4: switch to using the crc32c library
  lib/crc32: make crc32c() go directly to lib
  bcachefs: Explicitly select CRYPTO from BCACHEFS_FS
  x86/crc32: expose CRC32 functions through lib
  x86/crc32: update prototype for crc32_pclmul_le_16()
  ...

jbd2: flush filesystem device before updating tail sequence

2024-12-04T11:00:05+00:00

When committing transaction in jbd2_journal_commit_transaction(), the
disk caches for the filesystem device should be flushed before updating
the journal tail sequence. However, this step is missed if the journal
is not located on the filesystem device. As a result, the filesystem may
become inconsistent following a power failure or system crash. Fix it by
ensuring that the filesystem device is flushed appropriately.

Fixes: 3339578f0578 ("jbd2: cleanup journal tail after transaction commit")
Signed-off-by: Zhang Yi 
Link: https://lore.kernel.org/r/20241203014407.805916-3-yi.zhang@huaweicloud.com
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

jbd2: increase IO priority for writing revoke records

2024-12-04T11:00:05+00:00

Commit '6a3afb6ac6df ("jbd2: increase the journal IO's priority")'
increases the priority of journal I/O by marking I/O with the
JBD2_JOURNAL_REQ_FLAGS. However, that commit missed the revoke buffers,
so also addresses that kind of I/Os.

Fixes: 6a3afb6ac6df ("jbd2: increase the journal IO's priority")
Signed-off-by: Zhang Yi 
Link: https://lore.kernel.org/r/20241203014407.805916-2-yi.zhang@huaweicloud.com
Reviewed-by: Kemeng Shi 
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

jbd2: switch to using the crc32c library

2024-12-02T01:23:02+00:00

Now that the crc32c() library function directly takes advantage of
architecture-specific optimizations, it is unnecessary to go through the
crypto API.  Just use crc32c().  This is much simpler, and it improves
performance due to eliminating the crypto API overhead.

Reviewed-by: Ard Biesheuvel 
Reviewed-by: Darrick J. Wong 
Acked-by: Theodore Ts'o 
Link: https://lore.kernel.org/r/20241202010844.144356-18-ebiggers@kernel.org
Signed-off-by: Eric Biggers