[PATCH 3/6 v5] fs_pin: Kill fs_pin under a reference of vfsmnt

[Kinglong Mee <kinglongmee@gmail.com>]

v5, new patch

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
---
 fs/namespace.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index 1b9e111..3f08a48 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1049,8 +1049,6 @@ static void cleanup_mnt(struct mount *mnt)
 	 * so mnt_get_writers() below is safe.
 	 */
 	WARN_ON(mnt_get_writers(mnt));
-	if (unlikely(mnt->mnt_pins.first))
-		mnt_pin_kill(mnt);
 	fsnotify_vfsmount_delete(&mnt->mnt);
 	dput(mnt->mnt.mnt_root);
 	deactivate_super(mnt->mnt.mnt_sb);
@@ -1078,6 +1076,7 @@ static DECLARE_DELAYED_WORK(delayed_mntput_work, delayed_mntput);
 
 static void mntput_no_expire(struct mount *mnt)
 {
+put_again:
 	rcu_read_lock();
 	mnt_add_count(mnt, -1);
 	if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */
@@ -1090,6 +1089,13 @@ static void mntput_no_expire(struct mount *mnt)
 		unlock_mount_hash();
 		return;
 	}
+	if (unlikely(mnt->mnt_pins.first)) {
+		mnt_add_count(mnt, 1);
+		rcu_read_unlock();
+		unlock_mount_hash();
+		mnt_pin_kill(mnt);
+		goto put_again;
+	}
 	if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) {
 		rcu_read_unlock();
 		unlock_mount_hash();
-- 
2.4.3