3 files changed, 33 insertions, 0 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index c0237c602f11..755ee8164880 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2835,6 +2835,27 @@ corrupt_out:
         return XFS_ERROR(EFSCORRUPTED);
 }
 
+void
+xfs_promote_inode(
+        struct xfs_inode        *ip)
+{
+        struct xfs_buf          *bp;
+
+        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
+
+        bp = xfs_incore(ip->i_mount->m_ddev_targp, ip->i_imap.im_blkno,
+                        ip->i_imap.im_len, XBF_TRYLOCK);
+        if (!bp)
+                return;
+
+        if (XFS_BUF_ISDELAYWRITE(bp)) {
+                xfs_buf_delwri_promote(bp);
+                wake_up_process(ip->i_mount->m_ddev_targp->bt_task);
+        }
+
+        xfs_buf_relse(bp);
+}
+
 /*
  * Return a pointer to the extent record at file index idx.
  */
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 760140d1dd66..b4cd4739f98e 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -498,6 +498,7 @@ int		xfs_iunlink(struct xfs_trans *, xfs_inode_t *);
 void            xfs_iext_realloc(xfs_inode_t *, int, int);
 void            xfs_iunpin_wait(xfs_inode_t *);
 int             xfs_iflush(xfs_inode_t *, uint);
+void            xfs_promote_inode(struct xfs_inode *);
 void            xfs_lock_inodes(xfs_inode_t **, int, uint);
 void            xfs_lock_two_inodes(xfs_inode_t *, xfs_inode_t *, uint);
 
diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c
index aa3dc1a4d53d..be5c51d8f757 100644
--- a/fs/xfs/xfs_sync.c
+++ b/fs/xfs/xfs_sync.c
@@ -770,6 +770,17 @@ restart:
         if (!xfs_iflock_nowait(ip)) {
                 if (!(sync_mode & SYNC_WAIT))
                         goto out;
+
+                /*
+                 * If we only have a single dirty inode in a cluster there is
+                 * a fair chance that the AIL push may have pushed it into
+                 * the buffer, but xfsbufd won't touch it until 30 seconds
+                 * from now, and thus we will lock up here.
+                 *
+                 * Promote the inode buffer to the front of the delwri list
+                 * and wake up xfsbufd now.
+                 */
+                xfs_promote_inode(ip);
                 xfs_iflock(ip);
         }