4 files changed, 26 insertions, 51 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index c6b24e7c308..a4e07974955 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -1407,7 +1407,7 @@ xfs_fs_freeze(
 
         xfs_save_resvblks(mp);
         xfs_quiesce_attr(mp);
-        return -xfs_fs_log_dummy(mp);
+        return -xfs_fs_log_dummy(mp, SYNC_WAIT);
 }
 
 STATIC int
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index dfcbd98d159..d59c4a65d49 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -34,6 +34,7 @@
 #include "xfs_inode_item.h"
 #include "xfs_quota.h"
 #include "xfs_trace.h"
+#include "xfs_fsops.h"
 
 #include <linux/kthread.h>
 #include <linux/freezer.h>
@@ -341,38 +342,6 @@ xfs_sync_attr(
 }
 
 STATIC int
-xfs_commit_dummy_trans(
-        struct xfs_mount        *mp,
-        uint                    flags)
-{
-        struct xfs_inode        *ip = mp->m_rootip;
-        struct xfs_trans        *tp;
-        int                     error;
-
-        /*
-         * Put a dummy transaction in the log to tell recovery
-         * that all others are OK.
-         */
-        tp = xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
-        error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
-        if (error) {
-                xfs_trans_cancel(tp, 0);
-                return error;
-        }
-
-        xfs_ilock(ip, XFS_ILOCK_EXCL);
-
-        xfs_trans_ijoin(tp, ip);
-        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-        error = xfs_trans_commit(tp, 0);
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
-        /* the log force ensures this transaction is pushed to disk */
-        xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
-        return error;
-}
-
-STATIC int
 xfs_sync_fsdata(
         struct xfs_mount        *mp)
 {
@@ -432,7 +401,7 @@ xfs_quiesce_data(
 
         /* mark the log as covered if needed */
         if (xfs_log_need_covered(mp))
-                error2 = xfs_commit_dummy_trans(mp, SYNC_WAIT);
+                error2 = xfs_fs_log_dummy(mp, SYNC_WAIT);
 
         /* flush data-only devices */
         if (mp->m_rtdev_targp)
@@ -563,7 +532,7 @@ xfs_flush_inodes(
 /*
  * Every sync period we need to unpin all items, reclaim inodes and sync
  * disk quotas.  We might need to cover the log to indicate that the
- * filesystem is idle.
+ * filesystem is idle and not frozen.
  */
 STATIC void
 xfs_sync_worker(
@@ -577,8 +546,9 @@ xfs_sync_worker(
                 xfs_reclaim_inodes(mp, 0);
                 /* dgc: errors ignored here */
                 error = xfs_qm_sync(mp, SYNC_TRYLOCK);
-                if (xfs_log_need_covered(mp))
-                        error = xfs_commit_dummy_trans(mp, 0);
+                if (mp->m_super->s_frozen == SB_UNFROZEN &&
+                    xfs_log_need_covered(mp))
+                        error = xfs_fs_log_dummy(mp, 0);
         }
         mp->m_sync_seq++;
         wake_up(&mp->m_wait_single_sync_task);
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index dbca5f5c37b..43b1d569933 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -604,31 +604,36 @@ out:
         return 0;
 }
 
+/*
+ * Dump a transaction into the log that contains no real change. This is needed
+ * to be able to make the log dirty or stamp the current tail LSN into the log
+ * during the covering operation.
+ *
+ * We cannot use an inode here for this - that will push dirty state back up
+ * into the VFS and then periodic inode flushing will prevent log covering from
+ * making progress. Hence we log a field in the superblock instead.
+ */
 int
 xfs_fs_log_dummy(
-        xfs_mount_t     *mp)
+        xfs_mount_t     *mp,
+        int             flags)
 {
         xfs_trans_t     *tp;
-        xfs_inode_t     *ip;
         int             error;
 
         tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP);
-        error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
+        error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
+                                        XFS_DEFAULT_LOG_COUNT);
         if (error) {
                 xfs_trans_cancel(tp, 0);
                 return error;
         }
 
-        ip = mp->m_rootip;
-        xfs_ilock(ip, XFS_ILOCK_EXCL);
-
-        xfs_trans_ijoin(tp, ip);
-        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-        xfs_trans_set_sync(tp);
-        error = xfs_trans_commit(tp, 0);
-
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
-        return error;
+        /* log the UUID because it is an unchanging field */
+        xfs_mod_sb(tp, XFS_SB_UUID);
+        if (flags & SYNC_WAIT)
+                xfs_trans_set_sync(tp);
+        return xfs_trans_commit(tp, 0);
 }
 
 int
diff --git a/fs/xfs/xfs_fsops.h b/fs/xfs/xfs_fsops.h
index 88435e0a77c..a786c5212c1 100644
--- a/fs/xfs/xfs_fsops.h
+++ b/fs/xfs/xfs_fsops.h
@@ -25,6 +25,6 @@ extern int xfs_fs_counts(xfs_mount_t *mp, xfs_fsop_counts_t *cnt);
 extern int xfs_reserve_blocks(xfs_mount_t *mp, __uint64_t *inval,
                                 xfs_fsop_resblks_t *outval);
 extern int xfs_fs_goingdown(xfs_mount_t *mp, __uint32_t inflags);
-extern int xfs_fs_log_dummy(xfs_mount_t *mp);
+extern int xfs_fs_log_dummy(xfs_mount_t *mp, int flags);
 
 #endif  /* __XFS_FSOPS_H__ */