VFS: Fix UP compile error in fs/namespace.c

mnt_longterm is there only on SMP

Reported-and-tested-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 24 insertions, 7 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 48809e21f27..9f544f35ed3 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -611,6 +611,21 @@ static void attach_mnt(struct vfsmount *mnt, struct path *path)
         list_add_tail(&mnt->mnt_child, &path->mnt->mnt_mounts);
 }
 
+static inline void __mnt_make_longterm(struct vfsmount *mnt)
+{
+#ifdef CONFIG_SMP
+        atomic_inc(&mnt->mnt_longterm);
+#endif
+}
+
+/* needs vfsmount lock for write */
+static inline void __mnt_make_shortterm(struct vfsmount *mnt)
+{
+#ifdef CONFIG_SMP
+        atomic_dec(&mnt->mnt_longterm);
+#endif
+}
+
 /*
  * vfsmount lock must be held for write
  */
@@ -626,7 +641,7 @@ static void commit_tree(struct vfsmount *mnt)
         list_add_tail(&head, &mnt->mnt_list);
         list_for_each_entry(m, &head, mnt_list) {
                 m->mnt_ns = n;
-                atomic_inc(&m->mnt_longterm);
+                __mnt_make_longterm(m);
         }
 
         list_splice(&head, n->list.prev);
@@ -1189,7 +1204,7 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
                 list_del_init(&p->mnt_list);
                 __touch_mnt_namespace(p->mnt_ns);
                 p->mnt_ns = NULL;
-                atomic_dec(&p->mnt_longterm);
+                __mnt_make_shortterm(p);
                 list_del_init(&p->mnt_child);
                 if (p->mnt_parent != p) {
                         p->mnt_parent->mnt_ghosts++;
@@ -2243,16 +2258,18 @@ static struct mnt_namespace *alloc_mnt_ns(void)
 
 void mnt_make_longterm(struct vfsmount *mnt)
 {
-        atomic_inc(&mnt->mnt_longterm);
+        __mnt_make_longterm(mnt);
 }
 
 void mnt_make_shortterm(struct vfsmount *mnt)
 {
+#ifdef CONFIG_SMP
         if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))
                 return;
         br_write_lock(vfsmount_lock);
         atomic_dec(&mnt->mnt_longterm);
         br_write_unlock(vfsmount_lock);
+#endif
 }
 
 /*
@@ -2292,17 +2309,17 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
         q = new_ns->root;
         while (p) {
                 q->mnt_ns = new_ns;
-                atomic_inc(&q->mnt_longterm);
+                __mnt_make_longterm(q);
                 if (fs) {
                         if (p == fs->root.mnt) {
                                 fs->root.mnt = mntget(q);
-                                atomic_inc(&q->mnt_longterm);
+                                __mnt_make_longterm(q);
                                 mnt_make_shortterm(p);
                                 rootmnt = p;
                         }
                         if (p == fs->pwd.mnt) {
                                 fs->pwd.mnt = mntget(q);
-                                atomic_inc(&q->mnt_longterm);
+                                __mnt_make_longterm(q);
                                 mnt_make_shortterm(p);
                                 pwdmnt = p;
                         }
@@ -2348,7 +2365,7 @@ struct mnt_namespace *create_mnt_ns(struct vfsmount *mnt)
         new_ns = alloc_mnt_ns();
         if (!IS_ERR(new_ns)) {
                 mnt->mnt_ns = new_ns;
-                atomic_inc(&mnt->mnt_longterm);
+                __mnt_make_longterm(mnt);
                 new_ns->root = mnt;
                 list_add(&new_ns->list, &new_ns->root->mnt_list);
         }