* this by simply making sure the log gets flushed
* if SYNC_BDFLUSH is set, and by actually writing it
* out otherwise.
+ * SYNC_IOWAIT - The caller wants us to wait for all data I/O to complete
+ * before we return (including direct I/O). Forms the drain
+ * side of the write barrier needed to safely quiesce the
+ * filesystem.
*
*/
/*ARGSUSED*/
{
xfs_mount_t *mp = XFS_BHVTOM(bdp);
- if (unlikely(flags == SYNC_QUIESCE))
- return xfs_quiesce_fs(mp);
- else
- return xfs_syncsub(mp, flags, NULL);
+ return xfs_syncsub(mp, flags, NULL);
}
/*
}
}
+ /*
+ * When freezing, we need to wait ensure all I/O (including direct
+ * I/O) is complete to ensure no further data modification can take
+ * place after this point
+ */
+ if (flags & SYNC_IOWAIT)
+ vn_iowait(vp);
if (flags & SYNC_BDFLUSH) {
if ((flags & SYNC_ATTR) &&
return 0;
}
+/*
+ * Second stage of a freeze. The data is already frozen, now we have to take
+ * care of the metadata. New transactions are already blocked, so we need to
+ * wait for any remaining transactions to drain out before proceding.
+ */
STATIC void
xfs_freeze(
bhv_desc_t *bdp)
{
xfs_mount_t *mp = XFS_BHVTOM(bdp);
+ /* wait for all modifications to complete */
while (atomic_read(&mp->m_active_trans) > 0)
delay(100);
+ /* flush inodes and push all remaining buffers out to disk */
+ xfs_quiesce_fs(mp);
+
+ ASSERT_ALWAYS(atomic_read(&mp->m_active_trans) == 0);
+
/* Push the superblock and write an unmount record */
xfs_log_unmount_write(mp);
xfs_unmountfs_writesb(mp);