We should not reuse the dirty bh in jbd2 directly due to the following
situation:
1. When removing extent rec, we will dirty the bhs of extent rec and
truncate log at the same time, and hand them over to jbd2.
2. The bhs are submitted to jbd2 area successfully.
3. The write-back thread of device help flush the bhs to disk but
encounter write error due to abnormal storage link.
4. After a while the storage link become normal. Truncate log flush
worker triggered by the next space reclaiming found the dirty bh of
truncate log and clear its 'BH_Write_EIO' and then set it uptodate in
__ocfs2_journal_access():
ocfs2_truncate_log_worker
ocfs2_flush_truncate_log
__ocfs2_flush_truncate_log
ocfs2_replay_truncate_records
ocfs2_journal_access_di
__ocfs2_journal_access // here we clear io_error and set 'tl_bh' uptodata.
5. Then jbd2 will flush the bh of truncate log to disk, but the bh of
extent rec is still in error state, and unfortunately nobody will
take care of it.
6. At last the space of extent rec was not reduced, but truncate log
flush worker have given it back to globalalloc. That will cause
duplicate cluster problem which could be identified by fsck.ocfs2.
Sadly we can hardly revert this but set fs read-only in case of ruining
atomicity and consistency of space reclaim.
Link: http://lkml.kernel.org/r/5A6E8092.8090701@huawei.com
Fixes: acf8fdbe6a ("ocfs2: do not BUG if buffer not uptodate in __ocfs2_journal_access")
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d984187e3a