ACPI: Introduce acpi_os_get_iomem()

[linux.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 48809e21f2706e37e366c6900c40a906aa1919b2..7b0b95371696117494af637af71c24d6752a3939 100644 (file)
--- 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++;
@@ -1857,6 +1872,8 @@ out:
        return err;
 }
 
+static int do_add_mount(struct vfsmount *, struct path *, int);
+
 /*
  * create a new mount for userspace and request it to be added into the
  * namespace's tree
@@ -1865,6 +1882,7 @@ static int do_new_mount(struct path *path, char *type, int flags,
                        int mnt_flags, char *name, void *data)
 {
        struct vfsmount *mnt;
+       int err;
 
        if (!type)
                return -EINVAL;
@@ -1877,14 +1895,47 @@ static int do_new_mount(struct path *path, char *type, int flags,
        if (IS_ERR(mnt))
                return PTR_ERR(mnt);
 
-       return do_add_mount(mnt, path, mnt_flags);
+       err = do_add_mount(mnt, path, mnt_flags);
+       if (err)
+               mntput(mnt);
+       return err;
+}
+
+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) {
+               err = -ELOOP;
+               goto fail;
+       }
+
+       err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
+       if (!err)
+               return 0;
+fail:
+       /* remove m from any expiration list it may be on */
+       if (!list_empty(&m->mnt_expire)) {
+               down_write(&namespace_sem);
+               br_write_lock(vfsmount_lock);
+               list_del_init(&m->mnt_expire);
+               br_write_unlock(vfsmount_lock);
+               up_write(&namespace_sem);
+       }
+       mntput(m);
+       mntput(m);
+       return err;
 }
 
 /*
  * add a mount into a namespace's mount tree
- * - this unconditionally eats one of the caller's references to newmnt.
  */
-int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
+static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
 {
        int err;
 
@@ -1911,15 +1962,10 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
                goto unlock;
 
        newmnt->mnt_flags = mnt_flags;
-       if ((err = graft_tree(newmnt, path)))
-               goto unlock;
-
-       up_write(&namespace_sem);
-       return 0;
+       err = graft_tree(newmnt, path);
 
 unlock:
        up_write(&namespace_sem);
-       mntput(newmnt);
        return err;
 }
 
@@ -1940,20 +1986,6 @@ void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)
 }
 EXPORT_SYMBOL(mnt_set_expiry);
 
-/*
- * Remove a vfsmount from any expiration list it may be on
- */
-void mnt_clear_expiry(struct vfsmount *mnt)
-{
-       if (!list_empty(&mnt->mnt_expire)) {
-               down_write(&namespace_sem);
-               br_write_lock(vfsmount_lock);
-               list_del_init(&mnt->mnt_expire);
-               br_write_unlock(vfsmount_lock);
-               up_write(&namespace_sem);
-       }
-}
-
 /*
  * process a list of expirable mountpoints with the intent of discarding any
  * mountpoints that aren't in use and haven't been touched since last we came
@@ -2243,16 +2275,18 @@ 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 +2326,17 @@ 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 +2382,7 @@ 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);
        }