user/sven/linux.git/include/linux/jbd2.h, branch v5.15.80

ext4: fast commit may not fallback for ineligible commit

2022-03-08T18:12:32Z

[ Upstream commit e85c81ba8859a4c839bcd69c5d83b32954133a5b ] For the follow scenario: 1. jbd start commit transaction n 2. task A get new handle for transaction n+1 3. task A do some ineligible actions and mark FC_INELIGIBLE 4. jbd complete transaction n and clean FC_INELIGIBLE 5. task A call fsync In this case fast commit will not fallback to full commit and transaction n+1 also not handled by jbd. Make ext4_fc_mark_ineligible() also record transaction tid for latest ineligible case, when call ext4_fc_cleanup() check current transaction tid, if small than latest ineligible tid do not clear the EXT4_MF_FC_INELIGIBLE. Reported-by: kernel test robot Reported-by: Dan Carpenter Reported-by: Ritesh Harjani Suggested-by: Harshad Shirwadkar Signed-off-by: Xin Yin Link: https://lore.kernel.org/r/20220117093655.35160-2-yinxin.x@bytedance.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Sasha Levin

ext4: inline jbd2_journal_[un]register_shrinker()

2021-07-08T12:37:31Z

The function jbd2_journal_unregister_shrinker() was getting called twice when the file system was getting unmounted. On Power and ARM platforms this was causing kernel crash when unmounting the file system, when a percpu_counter was destroyed twice. Fix this by removing jbd2_journal_[un]register_shrinker() functions, and inlining the shrinker setup and teardown into journal_init_common() and jbd2_journal_destroy(). This means that ext4 and ocfs2 now no longer need to know about registering and unregistering jbd2's shrinker. Also, while we're at it, rename the percpu counter from j_jh_shrink_count to j_checkpoint_jh_count, since this makes it clearer what this counter is intended to track. Link: https://lore.kernel.org/r/20210705145025.3363130-1-tytso@mit.edu Fixes: 4ba3fcdde7e3 ("jbd2,ext4: add a shrinker to release checkpointed buffers") Reported-by: Jon Hunter Reported-by: Sachin Sant Tested-by: Sachin Sant Tested-by: Jon Hunter Reviewed-by: Jan Kara Signed-off-by: Theodore Ts'o

jbd2,ext4: add a shrinker to release checkpointed buffers

2021-06-24T14:54:49Z

Current metadata buffer release logic in bdev_try_to_free_page() have a lot of use-after-free issues when umount filesystem concurrently, and it is difficult to fix directly because ext4 is the only user of s_op->bdev_try_to_free_page callback and we may have to add more special refcount or lock that is only used by ext4 into the common vfs layer, which is unacceptable. One better solution is remove the bdev_try_to_free_page callback, but the real problem is we cannot easily release journal_head on the checkpointed buffer, so try_to_free_buffers() cannot release buffers and page under memory pressure, which is more likely to trigger out-of-memory. So we cannot remove the callback directly before we find another way to release journal_head. This patch introduce a shrinker to free journal_head on the checkpointed transaction. After the journal_head got freed, try_to_free_buffers() could free buffer properly. Signed-off-by: Zhang Yi Suggested-by: Jan Kara Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20210610112440.3438139-6-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o

jbd2: ensure abort the journal if detect IO error when writing original buffer back

2021-06-24T14:33:49Z

Although we merged c044f3d8360 ("jbd2: abort journal if free a async write error metadata buffer"), there is a race between jbd2_journal_try_to_free_buffers() and jbd2_journal_destroy(), so the jbd2_log_do_checkpoint() may still fail to detect the buffer write io error flag which may lead to filesystem inconsistency. jbd2_journal_try_to_free_buffers() ext4_put_super() jbd2_journal_destroy() __jbd2_journal_remove_checkpoint() detect buffer write error jbd2_log_do_checkpoint() jbd2_cleanup_journal_tail() <--- lead to inconsistency jbd2_journal_abort() Fix this issue by introducing a new atomic flag which only have one JBD2_CHECKPOINT_IO_ERROR bit now, and set it in __jbd2_journal_remove_checkpoint() when freeing a checkpoint buffer which has write_io_error flag. Then jbd2_journal_destroy() will detect this mark and abort the journal to prevent updating log tail. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20210610112440.3438139-3-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o

ext4: add discard/zeroout flags to journal flush

2021-06-22T23:27:10Z

Add a flags argument to jbd2_journal_flush to enable discarding or zero-filling the journal blocks while flushing the journal. Signed-off-by: Leah Rumancik Link: https://lore.kernel.org/r/20210518151327.130198-1-leah.rumancik@gmail.com Signed-off-by: Theodore Ts'o

jbd2: avoid -Wempty-body warnings

2021-04-06T02:39:38Z

Building with 'make W=1' shows a harmless -Wempty-body warning: fs/jbd2/recovery.c: In function 'fc_do_one_pass': fs/jbd2/recovery.c:267:75: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body] 267 | jbd_debug(3, "Fast commit replay failed, err = %d\n", err); | ^ Change the empty dprintk() macros to no_printk(), which avoids this warning and adds format string checking. Signed-off-by: Arnd Bergmann Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20210322102152.95684-1-arnd@kernel.org Signed-off-by: Theodore Ts'o

Updated locking documentation for transaction_t

2021-04-02T15:37:58Z

Some members of transaction_t are allowed to be read without any lock being held if accessed from the correct context. We used LockDoc's findings to determine those members. Each member of them is marked with a short comment: "no lock needed for jbd2 thread". Signed-off-by: Alexander Lochmann Signed-off-by: Horst Schirmeier Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20210211171410.17984-1-alexander.lochmann@tu-dortmund.de Signed-off-by: Theodore Ts'o

ext4: updated locking documentation for journal_t

2021-04-02T15:37:58Z

Some members of transaction_t are allowed to be read without any lock being held if consistency doesn't matter. Based on LockDoc's findings, we extended the locking documentation of those members. Each one of them is marked with a short comment: "no lock for quick racy checks". Signed-off-by: Alexander Lochmann Signed-off-by: Horst Schirmeier Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/ad82c7a9-a624-4ed5-5ada-a6410c44c0b3@tu-dortmund.de Signed-off-by: Theodore Ts'o

jbd2: add a helper to find out number of fast commit blocks

2020-12-17T18:30:45Z

Add a helper to read number of fast commit blocks from jbd2 superblock and also rename the JBD2_MIN_FC_BLKS to JBD2_DEFAULT_FAST_COMMIT_BLOCKS since this constant is just the default number of fast commit blocks to use in case number of fast commit blocks isn't set in jbd2 superblock. Signed-off-by: Harshad Shirwadkar Link: https://lore.kernel.org/r/20201120202232.2240293-2-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o

Updated locking documentation for transaction_t

2020-12-03T14:00:55Z

We used LockDoc to derive locking rules for each member of struct transaction_t. Based on those results, we extended the existing documentation by more members of struct transaction_t, and updated the existing documentation. Link: https://lore.kernel.org/r/10cfbef1-994c-c604-f8a6-b1042fcc622f@tu-dortmund.de Signed-off-by: Alexander Lochmann Signed-off-by: Horst Schirmeier Signed-off-by: Theodore Ts'o