devpts: hoist out check for DEVPTS_SUPER_MAGIC

commit 7d71109df186d630a41280670c8d71d0cf9b0da9 upstream.

Hoist the check whether we have already found a suitable devpts filesystem
out of devpts_ptmx_path() in preparation for the devpts bind-mount
resolution patch. This is a non-functional change.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index e31d6ed3ec3275dcae2b5362f562ecdb43d54bcd..71b901936113d019f0bca169cca4a51154effab8 100644 (file)
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -138,10 +138,6 @@ static int devpts_ptmx_path(struct path *path)
        struct super_block *sb;
        int err;
 
-       /* Has the devpts filesystem already been found? */
-       if (path->mnt->mnt_sb->s_magic == DEVPTS_SUPER_MAGIC)
-               return 0;
-
        /* Is a devpts filesystem at "pts" in the same directory? */
        err = path_pts(path);
        if (err)
@@ -159,21 +155,25 @@ static int devpts_ptmx_path(struct path *path)
 struct vfsmount *devpts_mntget(struct file *filp, struct pts_fs_info *fsi)
 {
        struct path path;
-       int err;
+       int err = 0;
 
        path = filp->f_path;
        path_get(&path);
 
-       err = devpts_ptmx_path(&path);
+       /* Has the devpts filesystem already been found? */
+       if (path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC)
+               err = devpts_ptmx_path(&path);
        dput(path.dentry);
        if (err) {
                mntput(path.mnt);
                return ERR_PTR(err);
        }
+
        if (DEVPTS_SB(path.mnt->mnt_sb) != fsi) {
                mntput(path.mnt);
                return ERR_PTR(-ENODEV);
        }
+
        return path.mnt;
 }
 
@@ -182,15 +182,19 @@ struct pts_fs_info *devpts_acquire(struct file *filp)
        struct pts_fs_info *result;
        struct path path;
        struct super_block *sb;
-       int err;
 
        path = filp->f_path;
        path_get(&path);
 
-       err = devpts_ptmx_path(&path);
-       if (err) {
-               result = ERR_PTR(err);
-               goto out;
+       /* Has the devpts filesystem already been found? */
+       if (path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC) {
+               int err;
+
+               err = devpts_ptmx_path(&path);
+               if (err) {
+                       result = ERR_PTR(err);
+                       goto out;
+               }
        }
 
        /*