diff options
| -rw-r--r-- | fs/devpts/inode.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 71b901936113..542364bf923e 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -160,21 +160,27 @@ struct vfsmount *devpts_mntget(struct file *filp, struct pts_fs_info *fsi) path = filp->f_path; path_get(&path); - /* Has the devpts filesystem already been found? */ - if (path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC) + /* Walk upward while the start point is a bind mount of + * a single file. + */ + while (path.mnt->mnt_root == path.dentry) + if (follow_up(&path) == 0) + break; + + /* devpts_ptmx_path() finds a devpts fs or returns an error. */ + if ((path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC) || + (DEVPTS_SB(path.mnt->mnt_sb) != fsi)) err = devpts_ptmx_path(&path); dput(path.dentry); - if (err) { - mntput(path.mnt); - return ERR_PTR(err); - } + if (!err) { + if (DEVPTS_SB(path.mnt->mnt_sb) == fsi) + return path.mnt; - if (DEVPTS_SB(path.mnt->mnt_sb) != fsi) { - mntput(path.mnt); - return ERR_PTR(-ENODEV); + err = -ENODEV; } - return path.mnt; + mntput(path.mnt); + return ERR_PTR(err); } struct pts_fs_info *devpts_acquire(struct file *filp) |