kernel/git/stable/linux-stable.git/fs/jbd2, branch linux-6.4.y

jbd2: fix a race when checking checkpoint buffer busy

2023-08-30T12:52:28+00:00

[ Upstream commit 46f881b5b1758dc4a35fba4a643c10717d0cf427 ] Before removing checkpoint buffer from the t_checkpoint_list, we have to check both BH_Dirty and BH_Lock bits together to distinguish buffers have not been or were being written back. But __cp_buffer_busy() checks them separately, it first check lock state and then check dirty, the window between these two checks could be raced by writing back procedure, which locks buffer and clears buffer dirty before I/O completes. So it cannot guarantee checkpointing buffers been written back to disk if some error happens later. Finally, it may clean checkpoint transactions and lead to inconsistent filesystem. jbd2_journal_forget() and __journal_try_to_free_buffer() also have the same problem (journal_unmap_buffer() escape from this issue since it's running under the buffer lock), so fix them through introducing a new helper to try holding the buffer lock and remove really clean buffer. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217490 Cc: stable@vger.kernel.org Suggested-by: Jan Kara Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230606135928.434610-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

jbd2: remove journal_clean_one_cp_list()

2023-08-30T12:52:28+00:00

[ Upstream commit b98dba273a0e47dbfade89c9af73c5b012a4eabb ] journal_clean_one_cp_list() and journal_shrink_one_cp_list() are almost the same, so merge them into journal_shrink_one_cp_list(), remove the nr_to_scan parameter, always scan and try to free the whole checkpoint list. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230606135928.434610-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 46f881b5b175 ("jbd2: fix a race when checking checkpoint buffer busy") Signed-off-by: Sasha Levin

jbd2: remove t_checkpoint_io_list

2023-08-30T12:52:28+00:00

[ Upstream commit be22255360f80d3af789daad00025171a65424a5 ] Since t_checkpoint_io_list was stop using in jbd2_log_do_checkpoint() now, it's time to remove the whole t_checkpoint_io_list logic. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230606135928.434610-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 46f881b5b175 ("jbd2: fix a race when checking checkpoint buffer busy") Signed-off-by: Sasha Levin

jbd2: Fix wrongly judgement for buffer head removing while doing checkpoint

2023-08-03T08:25:41+00:00

[ Upstream commit e34c8dd238d0c9368b746480f313055f5bab5040 ] Following process, jbd2_journal_commit_transaction // there are several dirty buffer heads in transaction->t_checkpoint_list P1 wb_workfn jbd2_log_do_checkpoint if (buffer_locked(bh)) // false __block_write_full_page trylock_buffer(bh) test_clear_buffer_dirty(bh) if (!buffer_dirty(bh)) __jbd2_journal_remove_checkpoint(jh) if (buffer_write_io_error(bh)) // false >> bh IO error occurs << jbd2_cleanup_journal_tail __jbd2_update_log_tail jbd2_write_superblock // The bh won't be replayed in next mount. , which could corrupt the ext4 image, fetch a reproducer in [Link]. Since writeback process clears buffer dirty after locking buffer head, we can fix it by try locking buffer and check dirtiness while buffer is locked, the buffer head can be removed if it is neither dirty nor locked. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217490 Fixes: 470decc613ab ("[PATCH] jbd2: initial copy of files from jbd") Signed-off-by: Zhihao Cheng Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230606135928.434610-5-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

jbd2: recheck chechpointing non-dirty buffer

2023-07-27T06:57:05+00:00

commit c2d6fd9d6f35079f1669f0100f05b46708c74b7f upstream. There is a long-standing metadata corruption issue that happens from time to time, but it's very difficult to reproduce and analyse, benefit from the JBD2_CYCLE_RECORD option, we found out that the problem is the checkpointing process miss to write out some buffers which are raced by another do_get_write_access(). Looks below for detail. jbd2_log_do_checkpoint() //transaction X //buffer A is dirty and not belones to any transaction __buffer_relink_io() //move it to the IO list __flush_batch() write_dirty_buffer() do_get_write_access() clear_buffer_dirty __jbd2_journal_file_buffer() //add buffer A to a new transaction Y lock_buffer(bh) //doesn't write out __jbd2_journal_remove_checkpoint() //finish checkpoint except buffer A //filesystem corrupt if the new transaction Y isn't fully write out. Due to the t_checkpoint_list walking loop in jbd2_log_do_checkpoint() have already handles waiting for buffers under IO and re-added new transaction to complete commit, and it also removing cleaned buffers, this makes sure the list will eventually get empty. So it's fine to leave buffers on the t_checkpoint_list while flushing out and completely stop using the t_checkpoint_io_list. Cc: stable@vger.kernel.org Suggested-by: Jan Kara Signed-off-by: Zhang Yi Tested-by: Zhihao Cheng Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230606135928.434610-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

jdb2: Don't refuse invalidation of already invalidated buffers

2023-04-14T23:38:50+00:00

When invalidating buffers under the partial tail page, jbd2_journal_invalidate_folio() returns -EBUSY if the buffer is part of the committing transaction as we cannot safely modify buffer state. However if the buffer is already invalidated (due to previous invalidation attempts from ext4_wait_for_tail_page_commit()), there's nothing to do and there's no point in returning -EBUSY. This fixes occasional warnings from ext4_journalled_invalidate_folio() triggered by generic/051 fstest when blocksize < pagesize. Fixes: 53e872681fed ("ext4: fix deadlock in journal_unmap_buffer()") Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230329154950.19720-1-jack@suse.cz Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-03-12T15:55:55+00:00

Pull ext4 fixes from Ted Ts'o: "Bug fixes and regressions for ext4, the most serious of which is a potential deadlock during directory renames that was introduced during the merge window discovered by a combination of syzbot and lockdep" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: zero i_disksize when initializing the bootloader inode ext4: make sure fs error flag setted before clear journal error ext4: commit super block if fs record error when journal record without error ext4, jbd2: add an optimized bmap for the journal inode ext4: fix WARNING in ext4_update_inline_data ext4: move where set the MAY_INLINE_DATA flag is set ext4: Fix deadlock during directory rename ext4: Fix comment about the 64BIT feature docs: ext4: modify the group desc size to 64 ext4: fix another off-by-one fsmap error on 1k block filesystems ext4: fix RENAME_WHITEOUT handling for inline directories ext4: make kobj_type structures constant ext4: fix cgroup writeback accounting with fs-layer encryption

ext4, jbd2: add an optimized bmap for the journal inode

2023-03-11T05:44:24+00:00

The generic bmap() function exported by the VFS takes locks and does checks that are not necessary for the journal inode. So allow the file system to set a journal-optimized bmap function in journal->j_bmap. Reported-by: syzbot+9543479984ae9e576000@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=e4aaa78795e490421c79f76ec3679006c8ff4cf0 Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-02-28T17:05:47+00:00

Pull ext4 updates from Ted Ts'o: "Improve performance for ext4 by allowing multiple process to perform direct I/O writes to preallocated blocks by using a shared inode lock instead of taking an exclusive lock. In addition, multiple bug fixes and cleanups" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix incorrect options show of original mount_opt and extend mount_opt2 ext4: Fix possible corruption when moving a directory ext4: init error handle resource before init group descriptors ext4: fix task hung in ext4_xattr_delete_inode jbd2: fix data missing when reusing bh which is ready to be checkpointed ext4: update s_journal_inum if it changes after journal replay ext4: fail ext4_iget if special inode unallocated ext4: fix function prototype mismatch for ext4_feat_ktype ext4: remove unnecessary variable initialization ext4: fix inode tree inconsistency caused by ENOMEM ext4: refuse to create ea block when umounted ext4: optimize ea_inode block expansion ext4: remove dead code in updating backup sb ext4: dio take shared inode lock when overwriting preallocated blocks ext4: don't show commit interval if it is zero ext4: use ext4_fc_tl_mem in fast-commit replay path ext4: improve xattr consistency checking and error reporting

jbd2: fix data missing when reusing bh which is ready to be checkpointed

2023-02-19T05:09:59+00:00

Following process will make data lost and could lead to a filesystem corrupted problem: 1. jh(bh) is inserted into T1->t_checkpoint_list, bh is dirty, and jh->b_transaction = NULL 2. T1 is added into journal->j_checkpoint_transactions. 3. Get bh prepare to write while doing checkpoing: PA PB do_get_write_access jbd2_log_do_checkpoint spin_lock(&jh->b_state_lock) if (buffer_dirty(bh)) clear_buffer_dirty(bh) // clear buffer dirty set_buffer_jbddirty(bh) transaction = journal->j_checkpoint_transactions jh = transaction->t_checkpoint_list if (!buffer_dirty(bh)) __jbd2_journal_remove_checkpoint(jh) // bh won't be flushed jbd2_cleanup_journal_tail __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved) 4. Aborting journal/Power-cut before writing latest bh on journal area. In this way we get a corrupted filesystem with bh's data lost. Fix it by moving the clearing of buffer_dirty bit just before the call to __jbd2_journal_file_buffer(), both bit clearing and jh->b_transaction assignment are under journal->j_list_lock locked, so that jbd2_log_do_checkpoint() will wait until jh's new transaction fininshed even bh is currently not dirty. And journal_shrink_one_cp_list() won't remove jh from checkpoint list if the buffer head is reused in do_get_write_access(). Fetch a reproducer in [Link]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216898 Cc: Signed-off-by: Zhihao Cheng Signed-off-by: zhanchengbin Suggested-by: Jan Kara Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230110015327.1181863-1-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o