Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
 "Assorted fixes.

  Some of that is only a matter with fault injection (broken handling of
  small allocation failure in various mount-related places), but the
  last one is a root-triggerable stack overflow, and combined with
  userns it gets really nasty ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Don't leak MNT_INTERNAL away from internal mounts
  mm,vmscan: Allow preallocating memory for register_shrinker().
  rpc_pipefs: fix double-dput()
  orangefs_kill_sb(): deal with allocation failures
  jffs2_kill_sb(): deal with failed allocations
  hypfs_kill_super(): deal with failed allocations

4 files changed, 12 insertions, 7 deletions

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index f60dee7..87bdf0f 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -342,7 +342,7 @@ static void jffs2_put_super (struct super_block *sb)
 static void jffs2_kill_sb(struct super_block *sb)
 {
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
-	if (!sb_rdonly(sb))
+	if (c && !sb_rdonly(sb))
 		jffs2_stop_garbage_collect_thread(c);
 	kill_mtd_super(sb);
 	kfree(c);
diff --git a/fs/namespace.c b/fs/namespace.c
index e398f32..8634d56 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1089,7 +1089,8 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
 			goto out_free;
 	}
 
-	mnt->mnt.mnt_flags = old->mnt.mnt_flags & ~(MNT_WRITE_HOLD|MNT_MARKED);
+	mnt->mnt.mnt_flags = old->mnt.mnt_flags;
+	mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL);
 	/* Don't allow unprivileged users to change mount flags */
 	if (flag & CL_UNPRIVILEGED) {
 		mnt->mnt.mnt_flags |= MNT_LOCK_ATIME;
diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
index 3ae5fdb..10796d3 100644
--- a/fs/orangefs/super.c
+++ b/fs/orangefs/super.c
@@ -579,6 +579,11 @@ void orangefs_kill_sb(struct super_block *sb)
 	/* provided sb cleanup */
 	kill_anon_super(sb);
 
+	if (!ORANGEFS_SB(sb)) {
+		mutex_lock(&orangefs_request_mutex);
+		mutex_unlock(&orangefs_request_mutex);
+		return;
+	}
 	/*
 	 * issue the unmount to userspace to tell it to remove the
 	 * dynamic mount info it has for this superblock
diff --git a/fs/super.c b/fs/super.c
index 5fa9a8d..122c402 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -167,6 +167,7 @@ static void destroy_unused_super(struct super_block *s)
 	security_sb_free(s);
 	put_user_ns(s->s_user_ns);
 	kfree(s->s_subtype);
+	free_prealloced_shrinker(&s->s_shrink);
 	/* no delays needed */
 	destroy_super_work(&s->destroy_work);
 }
@@ -252,6 +253,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
 	s->s_shrink.count_objects = super_cache_count;
 	s->s_shrink.batch = 1024;
 	s->s_shrink.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE;
+	if (prealloc_shrinker(&s->s_shrink))
+		goto fail;
 	return s;
 
 fail:
@@ -518,11 +521,7 @@ retry:
 	hlist_add_head(&s->s_instances, &type->fs_supers);
 	spin_unlock(&sb_lock);
 	get_filesystem(type);
-	err = register_shrinker(&s->s_shrink);
-	if (err) {
-		deactivate_locked_super(s);
-		s = ERR_PTR(err);
-	}
+	register_shrinker_prepared(&s->s_shrink);
 	return s;
 }