devpts: hoist out check for DEVPTS_SUPER_MAGIC

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>

1 files changed, 15 insertions, 11 deletions

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index e31d6ed3ec32..71b901936113 100644
--- 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;
+                }
         }
 
         /*