jbd: Write journal superblock with WRITE_FUA after checkpointing
If journal superblock is written only in disk's caches and other transaction
starts reusing space of the transaction cleaned from the log, it can happen
blocks of a new transaction reach the disk before journal superblock. When
power failure happens in such case, subsequent journal replay would still try
to replay the old transaction but some of it's blocks may be already
overwritten by the new transaction. For this reason we must use WRITE_FUA when
updating log tail and we must first write new log tail to disk and update
in-memory information only after that.
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/include/linux/jbd.h b/include/linux/jbd.h
index 9716d37..c8f3297 100644
--- a/include/linux/jbd.h
+++ b/include/linux/jbd.h
@@ -864,7 +864,8 @@
extern int journal_recover (journal_t *journal);
extern int journal_wipe (journal_t *, int);
extern int journal_skip_recovery (journal_t *);
-extern void journal_update_sb_log_tail (journal_t *);
+extern void journal_update_sb_log_tail (journal_t *, tid_t, unsigned int,
+ int);
extern void journal_abort (journal_t *, int);
extern int journal_errno (journal_t *);
extern void journal_ack_err (journal_t *);