xfs: xfs_quiesce_attr() should quiesce the log like unmount

[deliverable/linux.git] / fs / xfs / xfs_super.c

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 27d5a92e1210086000b3db6ba4baa31550d529c1..fdedf2cabae3a3936de1c4c4fe1525ccdadda9bd 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1057,7 +1057,6 @@ xfs_fs_sync_fs(
        int                     wait)
 {
        struct xfs_mount        *mp = XFS_M(sb);
-       int                     error;
 
        /*
         * Doing anything during the async pass would be counterproductive.
@@ -1065,10 +1064,7 @@ xfs_fs_sync_fs(
        if (!wait)
                return 0;
 
-       error = xfs_quiesce_data(mp);
-       if (error)
-               return -error;
-
+       xfs_log_force(mp, XFS_LOG_SYNC);
        if (laptop_mode) {
                /*
                 * The disk must be active because we're syncing.
@@ -1152,6 +1148,48 @@ xfs_restore_resvblks(struct xfs_mount *mp)
        xfs_reserve_blocks(mp, &resblks, NULL);
 }
 
+/*
+ * Trigger writeback of all the dirty metadata in the file system.
+ *
+ * This ensures that the metadata is written to their location on disk rather
+ * than just existing in transactions in the log. This means after a quiesce
+ * there is no log replay required to write the inodes to disk - this is the
+ * primary difference between a sync and a quiesce.
+ *
+ * Note: xfs_log_quiesce() stops background log work - the callers must ensure
+ * it is started again when appropriate.
+ */
+void
+xfs_quiesce_attr(
+       struct xfs_mount        *mp)
+{
+       int     error = 0;
+
+       /* wait for all modifications to complete */
+       while (atomic_read(&mp->m_active_trans) > 0)
+               delay(100);
+
+       /* force the log to unpin objects from the now complete transactions */
+       xfs_log_force(mp, XFS_LOG_SYNC);
+
+       /* reclaim inodes to do any IO before the freeze completes */
+       xfs_reclaim_inodes(mp, 0);
+       xfs_reclaim_inodes(mp, SYNC_WAIT);
+
+       /* Push the superblock and write an unmount record */
+       error = xfs_log_sbcount(mp);
+       if (error)
+               xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. "
+                               "Frozen image may not be consistent.");
+       /*
+        * Just warn here till VFS can correctly support
+        * read-only remount without racing.
+        */
+       WARN_ON(atomic_read(&mp->m_active_trans) != 0);
+
+       xfs_log_quiesce(mp);
+}
+
 STATIC int
 xfs_fs_remount(
        struct super_block      *sb,
@@ -1238,15 +1276,12 @@ xfs_fs_remount(
        /* rw -> ro */
        if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) {
                /*
-                * After we have synced the data but before we sync the
-                * metadata, we need to free up the reserve block pool so that
-                * the used block count in the superblock on disk is correct at
-                * the end of the remount. Stash the current reserve pool size
-                * so that if we get remounted rw, we can return it to the same
-                * size.
+                * Before we sync the metadata, we need to free up the reserve
+                * block pool so that the used block count in the superblock on
+                * disk is correct at the end of the remount. Stash the current
+                * reserve pool size so that if we get remounted rw, we can
+                * return it to the same size.
                 */
-
-               xfs_quiesce_data(mp);
                xfs_save_resvblks(mp);
                xfs_quiesce_attr(mp);
                mp->m_flags |= XFS_MOUNT_RDONLY;