Zhihao Cheng c325350d0c jbd2: fix data missing when reusing bh which is ready to be checkpointed ... commit e6b9bd7290 upstream. 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: <stable@kernel.org> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230110015327.1181863-1-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-03-10 09:40:05 +01:00
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Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
checkpoint.c	ext4: inline jbd2_journal_[un]register_shrinker()	2021-07-08 08:37:31 -04:00
commit.c	jbd2: wake up journal waiters in FIFO order, not LIFO	2022-10-26 12:34:28 +02:00
journal.c	jbd2: fix potential use-after-free in jbd2_fc_wait_bufs	2022-10-26 12:34:28 +02:00
recovery.c	jbd2: add miss release buffer head in fc_do_one_pass()	2022-10-26 12:34:28 +02:00
revoke.c	jbd2: Reserve space for revoke descriptor blocks	2019-11-05 16:00:48 -05:00
transaction.c	jbd2: fix data missing when reusing bh which is ready to be checkpointed	2023-03-10 09:40:05 +01:00