jbd2: flush filesystem device before updating tail sequence

jbd2: flush filesystem device before updating tail sequence

[ Upstream commit a0851ea9cd555c333795b85ddd908898b937c4e1 ]

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 <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20241203014407.805916-3-yi.zhang@huaweicloud.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>