wireguard-linux/fs/jbd2/checkpoint.c, branch update-toolchain

jbd2: add prefix 'jbd2' for 'shrink_type'

2024-05-09T14:52:31Z

As 'shrink_type' is exported. The module prefix 'jbd2' is added to distinguish from memory reclamation. Signed-off-by: Ye Bin Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://lore.kernel.org/r/20240407065355.1528580-3-yebin10@huawei.com Signed-off-by: Theodore Ts'o

jbd2: use shrink_type type instead of bool type for __jbd2_journal_clean_checkpoint_list()

2024-05-09T14:52:31Z

"enum shrink_type" can clearly express the meaning of the parameter of __jbd2_journal_clean_checkpoint_list(), and there is no need to use the bool type. Signed-off-by: Ye Bin Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://lore.kernel.org/r/20240407065355.1528580-2-yebin10@huawei.com Signed-off-by: Theodore Ts'o

jbd2: remove unused 'JBD2_CHECKPOINT_IO_ERROR' and 'j_atomic_flags'

2024-01-05T04:42:21Z

Since 'JBD2_CHECKPOINT_IO_ERROR' and j_atomic_flags' are not useful anymore after fs dev's errseq is imported into jbd2, just remove them. Signed-off-by: Zhihao Cheng Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20231213013224.2100050-4-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o

jbd2: remove unused function '__cp_buffer_busy'

2023-08-04T20:32:29Z

The code calling function '__cp_buffer_busy' has been removed, so the function should also be removed. silence the warning: fs/jbd2/checkpoint.c:48:20: warning: unused function '__cp_buffer_busy' Reported-by: Abaci Robot Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5518 Signed-off-by: Yang Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230714025528.564988-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o

jbd2: check 'jh->b_transaction' before removing it from checkpoint

2023-08-04T20:32:23Z

Following process will corrupt ext4 image: Step 1: jbd2_journal_commit_transaction __jbd2_journal_insert_checkpoint(jh, commit_transaction) // Put jh into trans1->t_checkpoint_list journal->j_checkpoint_transactions = commit_transaction // Put trans1 into journal->j_checkpoint_transactions Step 2: do_get_write_access test_clear_buffer_dirty(bh) // clear buffer dirty，set jbd dirty __jbd2_journal_file_buffer(jh, transaction) // jh belongs to trans2 Step 3: drop_cache journal_shrink_one_cp_list jbd2_journal_try_remove_checkpoint if (!trylock_buffer(bh)) // lock bh, true if (buffer_dirty(bh)) // buffer is not dirty __jbd2_journal_remove_checkpoint(jh) // remove jh from trans1->t_checkpoint_list Step 4: jbd2_log_do_checkpoint trans1 = journal->j_checkpoint_transactions // jh is not in trans1->t_checkpoint_list jbd2_cleanup_journal_tail(journal) // trans1 is done Step 5: Power cut, trans2 is not committed, jh is lost in next mounting. Fix it by checking 'jh->b_transaction' before remove it from checkpoint. Cc: stable@kernel.org Fixes: 46f881b5b175 ("jbd2: fix a race when checking checkpoint buffer busy") Signed-off-by: Zhihao Cheng Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230714025528.564988-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o

jbd2: fix checkpoint cleanup performance regression

2023-08-04T20:32:05Z

journal_clean_one_cp_list() has been merged into journal_shrink_one_cp_list(), but do chekpoint buffer cleanup from the committing process is just a best effort, it should stop scan once it meet a busy buffer, or else it will cause a lot of invalid buffer scan and checks. We catch a performance regression when doing fs_mark tests below. Test cmd: ./fs_mark -d scratch -s 1024 -n 10000 -t 1 -D 100 -N 100 Before merging checkpoint buffer cleanup: FSUse% Count Size Files/sec App Overhead 95 10000 1024 8304.9 49033 After merging checkpoint buffer cleanup: FSUse% Count Size Files/sec App Overhead 95 10000 1024 7649.0 50012 FSUse% Count Size Files/sec App Overhead 95 10000 1024 2107.1 50871 After merging checkpoint buffer cleanup, the total loop count in journal_shrink_one_cp_list() could be up to 6,261,600+ (50,000+ ~ 100,000+ in general), most of them are invalid. This patch fix it through passing 'shrink_type' into journal_shrink_one_cp_list() and add a new 'SHRINK_BUSY_STOP' to indicate it should stop once meet a busy buffer. After fix, the loop count descending back to 10,000+. After this fix: FSUse% Count Size Files/sec App Overhead 95 10000 1024 8558.4 49109 Cc: stable@kernel.org Fixes: b98dba273a0e ("jbd2: remove journal_clean_one_cp_list()") Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230714025528.564988-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o

jbd2: fix a race when checking checkpoint buffer busy

2023-07-11T03:09:21Z

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

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

2023-07-11T03:09:21Z

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

jbd2: remove journal_clean_one_cp_list()

2023-07-11T03:09:21Z

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

jbd2: remove t_checkpoint_io_list

2023-07-11T03:09:21Z

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