Take the completion of automount into new helper

... and shift it from namei.c to namespace.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 39 insertions, 26 deletions

diff --git a/fs/internal.h b/fs/internal.h
index 12ccb86edef7..e8a0b245177d 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -70,6 +70,7 @@ extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
 extern void release_mounts(struct list_head *);
 extern void umount_tree(struct vfsmount *, int, struct list_head *);
 extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int);
+extern int finish_automount(struct vfsmount *, struct path *);
 extern int do_add_mount(struct vfsmount *, struct path *, int);
 extern void mnt_clear_expiry(struct vfsmount *);
 
diff --git a/fs/namei.c b/fs/namei.c
index 8f7b41a14882..b753192d8c3f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -923,37 +923,13 @@ static int follow_automount(struct path *path, unsigned flags,
         if (!mnt) /* mount collision */
                 return 0;
 
-        /* The new mount record should have at least 2 refs to prevent it being
-         * expired before we get a chance to add it
-         */
-        BUG_ON(mnt_get_count(mnt) < 2);
-
-        if (mnt->mnt_sb == path->mnt->mnt_sb &&
-            mnt->mnt_root == path->dentry) {
-                mnt_clear_expiry(mnt);
-                mntput(mnt);
-                mntput(mnt);
-                return -ELOOP;
-        }
+        err = finish_automount(mnt, path);
 
-        /* We need to add the mountpoint to the parent.  The filesystem may
-         * have placed it on an expiry list, and so we need to make sure it
-         * won't be expired under us if do_add_mount() fails (do_add_mount()
-         * will eat a reference unconditionally).
-         */
-        mntget(mnt);
-        err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
         switch (err) {
         case -EBUSY:
                 /* Someone else made a mount here whilst we were busy */
-                err = 0;
-        default:
-                mnt_clear_expiry(mnt);
-                mntput(mnt);
-                mntput(mnt);
-                return err;
+                return 0;
         case 0:
-                mntput(mnt);
                 dput(path->dentry);
                 if (*need_mntput)
                         mntput(path->mnt);
@@ -961,7 +937,10 @@ static int follow_automount(struct path *path, unsigned flags,
                 path->dentry = dget(mnt->mnt_root);
                 *need_mntput = true;
                 return 0;
+        default:
+                return err;
         }
+
 }
 
 /*
diff --git a/fs/namespace.c b/fs/namespace.c
index 9f544f35ed34..bec51e4e0549 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1895,6 +1895,39 @@ static int do_new_mount(struct path *path, char *type, int flags,
         return do_add_mount(mnt, path, mnt_flags);
 }
 
+int finish_automount(struct vfsmount *m, struct path *path)
+{
+        int err;
+        /* The new mount record should have at least 2 refs to prevent it being
+         * expired before we get a chance to add it
+         */
+        BUG_ON(mnt_get_count(m) < 2);
+
+        if (m->mnt_sb == path->mnt->mnt_sb &&
+            m->mnt_root == path->dentry) {
+                mnt_clear_expiry(m);
+                mntput(m);
+                mntput(m);
+                return -ELOOP;
+        }
+
+        /* We need to add the mountpoint to the parent.  The filesystem may
+         * have placed it on an expiry list, and so we need to make sure it
+         * won't be expired under us if do_add_mount() fails (do_add_mount()
+         * will eat a reference unconditionally).
+         */
+        mntget(m);
+        err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
+        if (err) {
+                mnt_clear_expiry(m);
+                mntput(m);
+                mntput(m);
+        } else {
+                mntput(m);
+        }
+        return err;
+}
+
 /*
  * add a mount into a namespace's mount tree
  * - this unconditionally eats one of the caller's references to newmnt.