fix get_active_super()/umount() race
This one needs restarts...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index 4df8233..44971d7 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -471,17 +471,17 @@
if (!bdev)
return NULL;
+restart:
spin_lock(&sb_lock);
list_for_each_entry(sb, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
- if (sb->s_bdev != bdev)
- continue;
-
- if (grab_super(sb)) /* drops sb_lock */
- return sb;
-
- spin_lock(&sb_lock);
+ if (sb->s_bdev == bdev) {
+ if (grab_super(sb)) /* drops sb_lock */
+ return sb;
+ else
+ goto restart;
+ }
}
spin_unlock(&sb_lock);
return NULL;