X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=fs%2Fsuper.c;h=68307c029228c51efc0e7967c90c39edd1a85113;hb=a08797e853e27fedb2468d4fd45459fd62902143;hp=7465d4364208a2e751d2d3a7c8a8c1cc10d2d7c3;hpb=bef086e08e8281fe6ccf764b83cb9b12791466ed;p=~andy%2Flinux

diff --git a/fs/super.c b/fs/super.c
index 7465d436420..68307c02922 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -336,19 +336,19 @@ EXPORT_SYMBOL(deactivate_super);
  *	and want to turn it into a full-blown active reference.  grab_super()
  *	is called with sb_lock held and drops it.  Returns 1 in case of
  *	success, 0 if we had failed (superblock contents was already dead or
- *	dying when grab_super() had been called).
+ *	dying when grab_super() had been called).  Note that this is only
+ *	called for superblocks not in rundown mode (== ones still on ->fs_supers
+ *	of their type), so increment of ->s_count is OK here.
  */
 static int grab_super(struct super_block *s) __releases(sb_lock)
 {
-	if (atomic_inc_not_zero(&s->s_active)) {
-		spin_unlock(&sb_lock);
-		return 1;
-	}
-	/* it's going away */
 	s->s_count++;
 	spin_unlock(&sb_lock);
-	/* wait for it to die */
 	down_write(&s->s_umount);
+	if ((s->s_flags & MS_BORN) && atomic_inc_not_zero(&s->s_active)) {
+		put_super(s);
+		return 1;
+	}
 	up_write(&s->s_umount);
 	put_super(s);
 	return 0;
@@ -463,11 +463,6 @@ retry:
 				destroy_super(s);
 				s = NULL;
 			}
-			down_write(&old->s_umount);
-			if (unlikely(!(old->s_flags & MS_BORN))) {
-				deactivate_locked_super(old);
-				goto retry;
-			}
 			return old;
 		}
 	}
@@ -660,10 +655,10 @@ restart:
 		if (hlist_unhashed(&sb->s_instances))
 			continue;
 		if (sb->s_bdev == bdev) {
-			if (grab_super(sb)) /* drops sb_lock */
-				return sb;
-			else
+			if (!grab_super(sb))
 				goto restart;
+			up_write(&sb->s_umount);
+			return sb;
 		}
 	}
 	spin_unlock(&sb_lock);