Merge branch 'stable/cleancache.v13' into linux-next

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / super.c

diff --git a/fs/super.c b/fs/super.c
index e5d9765..fe5a7b3 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -634,6 +634,28 @@ rescan:
 EXPORT_SYMBOL(get_super);
 
 /**
+ *     get_super_thawed - get thawed superblock of a device
+ *     @bdev: device to get the superblock for
+ *
+ *     Scans the superblock list and finds the superblock of the file system
+ *     mounted on the device. The superblock is returned once it is thawed
+ *     (or immediately if it was not frozen). %NULL is returned if no match
+ *     is found.
+ */
+struct super_block *get_super_thawed(struct block_device *bdev)
+{
+       while (1) {
+               struct super_block *s = get_super(bdev);
+               if (!s || s->s_frozen == SB_UNFROZEN)
+                       return s;
+               up_read(&s->s_umount);
+               vfs_check_frozen(s, SB_FREEZE_WRITE);
+               put_super(s);
+       }
+}
+EXPORT_SYMBOL(get_super_thawed);
+
+/**
  * get_active_super - get an active reference to the superblock of a device
  * @bdev: device to get the superblock for
  *
@@ -1186,6 +1208,8 @@ int freeze_super(struct super_block *sb)
                        printk(KERN_ERR
                                "VFS:Filesystem freeze failed\n");
                        sb->s_frozen = SB_UNFROZEN;
+                       smp_wmb();
+                       wake_up(&sb->s_wait_unfrozen);
                        deactivate_locked_super(sb);
                        return ret;
                }