devpts: Must release s_umount on error

We should drop the ->s_umount mutex if an error occurs after the
sget()/grab_super() call. This was introduced when adding support
for multiple instances of devpts and noticed during a code review/reorg.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index bff4052b05e7..140b43144cd8 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -385,6 +385,7 @@ static int new_pts_mount(struct file_system_type *fs_type, int flags,
 
 fail:
         dput(mnt->mnt_sb->s_root);
+        up_write(&mnt->mnt_sb->s_umount);
         deactivate_super(mnt->mnt_sb);
         return err;
 }
@@ -473,6 +474,7 @@ static int init_pts_mount(struct file_system_type *fs_type, int flags,
         err = mknod_ptmx(mnt->mnt_sb);
         if (err) {
                 dput(mnt->mnt_sb->s_root);
+                up_write(&mnt->mnt_sb->s_umount);
                 deactivate_super(mnt->mnt_sb);
         }