Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...

[pandora-kernel.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 120b8a6..a7bea8c 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1060,11 +1060,8 @@ static int do_umount(struct vfsmount *mnt, int flags)
                 * we just try to remount it readonly.
                 */
                down_write(&sb->s_umount);
-               if (!(sb->s_flags & MS_RDONLY)) {
-                       lock_kernel();
+               if (!(sb->s_flags & MS_RDONLY))
                        retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
-                       unlock_kernel();
-               }
                up_write(&sb->s_umount);
                return retval;
        }
@@ -1384,7 +1381,7 @@ static int graft_tree(struct vfsmount *mnt, struct path *path)
                goto out_unlock;
 
        err = -ENOENT;
-       if (IS_ROOT(path->dentry) || !d_unhashed(path->dentry))
+       if (!d_unlinked(path->dentry))
                err = attach_recursive_mnt(mnt, path, NULL);
 out_unlock:
        mutex_unlock(&path->dentry->d_inode->i_mutex);
@@ -1566,7 +1563,7 @@ static int do_move_mount(struct path *path, char *old_name)
        if (IS_DEADDIR(path->dentry->d_inode))
                goto out1;
 
-       if (!IS_ROOT(path->dentry) && d_unhashed(path->dentry))
+       if (d_unlinked(path->dentry))
                goto out1;
 
        err = -EINVAL;
@@ -1630,7 +1627,9 @@ static int do_new_mount(struct path *path, char *type, int flags,
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
 
+       lock_kernel();
        mnt = do_kern_mount(type, flags, name, data);
+       unlock_kernel();
        if (IS_ERR(mnt))
                return PTR_ERR(mnt);
 
@@ -1938,6 +1937,21 @@ dput_out:
        return retval;
 }
 
+static struct mnt_namespace *alloc_mnt_ns(void)
+{
+       struct mnt_namespace *new_ns;
+
+       new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
+       if (!new_ns)
+               return ERR_PTR(-ENOMEM);
+       atomic_set(&new_ns->count, 1);
+       new_ns->root = NULL;
+       INIT_LIST_HEAD(&new_ns->list);
+       init_waitqueue_head(&new_ns->poll);
+       new_ns->event = 0;
+       return new_ns;
+}
+
 /*
  * Allocate a new namespace structure and populate it with contents
  * copied from the namespace of the passed in task structure.
@@ -1949,14 +1963,9 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
        struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
        struct vfsmount *p, *q;
 
-       new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
-       if (!new_ns)
-               return ERR_PTR(-ENOMEM);
-
-       atomic_set(&new_ns->count, 1);
-       INIT_LIST_HEAD(&new_ns->list);
-       init_waitqueue_head(&new_ns->poll);
-       new_ns->event = 0;
+       new_ns = alloc_mnt_ns();
+       if (IS_ERR(new_ns))
+               return new_ns;
 
        down_write(&namespace_sem);
        /* First pass: copy the tree topology */
@@ -2020,6 +2029,24 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
        return new_ns;
 }
 
+/**
+ * create_mnt_ns - creates a private namespace and adds a root filesystem
+ * @mnt: pointer to the new root filesystem mountpoint
+ */
+struct mnt_namespace *create_mnt_ns(struct vfsmount *mnt)
+{
+       struct mnt_namespace *new_ns;
+
+       new_ns = alloc_mnt_ns();
+       if (!IS_ERR(new_ns)) {
+               mnt->mnt_ns = new_ns;
+               new_ns->root = mnt;
+               list_add(&new_ns->list, &new_ns->root->mnt_list);
+       }
+       return new_ns;
+}
+EXPORT_SYMBOL(create_mnt_ns);
+
 SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
                char __user *, type, unsigned long, flags, void __user *, data)
 {
@@ -2046,10 +2073,8 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
        if (retval < 0)
                goto out3;
 
-       lock_kernel();
        retval = do_mount((char *)dev_page, dir_page, (char *)type_page,
                          flags, (void *)data_page);
-       unlock_kernel();
        free_page(data_page);
 
 out3:
@@ -2129,9 +2154,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
        error = -ENOENT;
        if (IS_DEADDIR(new.dentry->d_inode))
                goto out2;
-       if (d_unhashed(new.dentry) && !IS_ROOT(new.dentry))
+       if (d_unlinked(new.dentry))
                goto out2;
-       if (d_unhashed(old.dentry) && !IS_ROOT(old.dentry))
+       if (d_unlinked(old.dentry))
                goto out2;
        error = -EBUSY;
        if (new.mnt == root.mnt ||
@@ -2249,10 +2274,14 @@ void __init mnt_init(void)
        init_mount_tree();
 }
 
-void __put_mnt_ns(struct mnt_namespace *ns)
+void put_mnt_ns(struct mnt_namespace *ns)
 {
-       struct vfsmount *root = ns->root;
+       struct vfsmount *root;
        LIST_HEAD(umount_list);
+
+       if (!atomic_dec_and_lock(&ns->count, &vfsmount_lock))
+               return;
+       root = ns->root;
        ns->root = NULL;
        spin_unlock(&vfsmount_lock);
        down_write(&namespace_sem);
@@ -2263,3 +2292,4 @@ void __put_mnt_ns(struct mnt_namespace *ns)
        release_mounts(&umount_list);
        kfree(ns);
 }
+EXPORT_SYMBOL(put_mnt_ns);