xfs: rework log recovery to submit buffers on LSN boundaries
The fix to log recovery to update the metadata LSN in recovered buffers
introduces the requirement that a buffer is submitted only once per
current LSN. Log recovery currently submits buffers on transaction
boundaries. This is not sufficient as the abstraction between log
records and transactions allows for various scenarios where multiple
transactions can share the same current LSN. If independent transactions
share an LSN and both modify the same buffer, log recovery can
incorrectly skip updates and leave the filesystem in an inconsisent
state.
In preparation for proper metadata LSN updates during log recovery,
update log recovery to submit buffers for write on LSN change boundaries
rather than transaction boundaries. Explicitly track the current LSN in
a new struct xlog field to handle the various corner cases of when the
current LSN may or may not change.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 765f084..2b6eec5 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -413,7 +413,8 @@
/* log record crc error injection factor */
uint32_t l_badcrc_factor;
#endif
-
+ /* log recovery lsn tracking (for buffer submission */
+ xfs_lsn_t l_recovery_lsn;
};
#define XLOG_BUF_CANCEL_BUCKET(log, blkno) \