ext4: Fix return value of ext4_split_unwritten_extents() to fix direct I/O

[safe/jmp/linux-2.6] / fs / sync.c

diff --git a/fs/sync.c b/fs/sync.c
index 1923409..d104591 100644 (file)
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -27,6 +27,13 @@
  */
 static int __sync_filesystem(struct super_block *sb, int wait)
 {
+       /*
+        * This should be safe, as we require bdi backing to actually
+        * write out data in the first place
+        */
+       if (!sb->s_bdi)
+               return 0;
+
        /* Avoid doing twice syncing and cache pruning for quota sync */
        if (!wait) {
                writeout_quota_sb(sb, -1);
@@ -101,7 +108,7 @@ restart:
                spin_unlock(&sb_lock);
 
                down_read(&sb->s_umount);
-               if (!(sb->s_flags & MS_RDONLY) && sb->s_root)
+               if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi)
                        __sync_filesystem(sb, wait);
                up_read(&sb->s_umount);
 
@@ -176,6 +183,7 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
                ret = err;
        return ret;
 }
+EXPORT_SYMBOL(file_fsync);
 
 /**
  * vfs_fsync_range - helper to sync a range of data & metadata to disk