1 files changed, 11 insertions, 3 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 0a4b03d8fcd6..d0fc4c5aaf15 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1544,12 +1544,20 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 
         trace_btrfs_sync_file(file, datasync);
 
+        /*
+         * We write the dirty pages in the range and wait until they complete
+         * out of the ->i_mutex. If so, we can flush the dirty pages by
+         * multi-task, and make the performance up.
+         */
+        ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+        if (ret)
+                return ret;
+
         mutex_lock(&inode->i_mutex);
 
         /*
-         * we wait first, since the writeback may change the inode, also wait
-         * ordered range does a filemape_write_and_wait_range which is why we
-         * don't do it above like other file systems.
+         * We flush the dirty pages again to avoid some dirty pages in the
+         * range being left.
          */
         atomic_inc(&root->log_batch);
         btrfs_wait_ordered_range(inode, start, end);