1 files changed, 12 insertions, 10 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index ae45f77765c0..25adfc3c693a 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -424,8 +424,6 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * WB_SYNC_HOLD is a hack for sys_sync(): reattach the inode to sb->s_dirty so
  * that it can be located for waiting on in __writeback_single_inode().
  *
- * Called under inode_lock.
- *
  * If `bdi' is non-zero then we're being asked to writeback a specific queue.
  * This function assumes that the blockdev superblock's inodes are backed by
  * a variety of queues, so all inodes are searched.  For other superblocks,
@@ -441,11 +439,12 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * on the writer throttling path, and we get decent balancing between many
  * throttled threads: we don't want them all piling up on inode_sync_wait.
  */
-static void
-sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
+void generic_sync_sb_inodes(struct super_block *sb,
+                                struct writeback_control *wbc)
 {
         const unsigned long start = jiffies;    /* livelock avoidance */
 
+        spin_lock(&inode_lock);
         if (!wbc->for_kupdate || list_empty(&sb->s_io))
                 queue_io(sb, wbc->older_than_this);
 
@@ -524,8 +523,16 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
                 if (!list_empty(&sb->s_more_io))
                         wbc->more_io = 1;
         }
+        spin_unlock(&inode_lock);
         return;         /* Leave any unwritten inodes on s_io */
 }
+EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
+
+static void sync_sb_inodes(struct super_block *sb,
+                                struct writeback_control *wbc)
+{
+        generic_sync_sb_inodes(sb, wbc);
+}
 
 /*
  * Start writeback of dirty pagecache data against all unlocked inodes.
@@ -565,11 +572,8 @@ restart:
                          * be unmounted by the time it is released.
                          */
                         if (down_read_trylock(&sb->s_umount)) {
-                                if (sb->s_root) {
-                                        spin_lock(&inode_lock);
+                                if (sb->s_root)
                                         sync_sb_inodes(sb, wbc);
-                                        spin_unlock(&inode_lock);
-                                }
                                 up_read(&sb->s_umount);
                         }
                         spin_lock(&sb_lock);
@@ -607,9 +611,7 @@ void sync_inodes_sb(struct super_block *sb, int wait)
                         (inodes_stat.nr_inodes - inodes_stat.nr_unused) +
                         nr_dirty + nr_unstable;
         wbc.nr_to_write += wbc.nr_to_write / 2;         /* Bit more for luck */
-        spin_lock(&inode_lock);
         sync_sb_inodes(sb, &wbc);
-        spin_unlock(&inode_lock);
 }
 
 /*