#endif
}
-struct vfsmount *alloc_vfsmnt(const char *name)
+static struct vfsmount *alloc_vfsmnt(const char *name)
{
struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
if (mnt) {
br_write_unlock(vfsmount_lock);
}
-void simple_set_mnt(struct vfsmount *mnt, struct super_block *sb)
-{
- mnt->mnt_sb = sb;
- mnt->mnt_root = dget(sb->s_root);
-}
-
-EXPORT_SYMBOL(simple_set_mnt);
-
-void free_vfsmnt(struct vfsmount *mnt)
+static void free_vfsmnt(struct vfsmount *mnt)
{
kfree(mnt->mnt_devname);
mnt_free_id(mnt);
return p;
}
+struct vfsmount *
+vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
+{
+ struct vfsmount *mnt;
+ struct dentry *root;
+
+ if (!type)
+ return ERR_PTR(-ENODEV);
+
+ mnt = alloc_vfsmnt(name);
+ if (!mnt)
+ return ERR_PTR(-ENOMEM);
+
+ if (flags & MS_KERNMOUNT)
+ mnt->mnt_flags = MNT_INTERNAL;
+
+ root = mount_fs(type, flags, name, data);
+ if (IS_ERR(root)) {
+ free_vfsmnt(mnt);
+ return ERR_CAST(root);
+ }
+
+ mnt->mnt_root = root;
+ mnt->mnt_sb = root->d_sb;
+ mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt_parent = mnt;
+ return mnt;
+}
+EXPORT_SYMBOL_GPL(vfs_kern_mount);
+
static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
int flag)
{
return err;
}
+static int lock_mount(struct path *path)
+{
+ struct vfsmount *mnt;
+retry:
+ mutex_lock(&path->dentry->d_inode->i_mutex);
+ if (unlikely(cant_mount(path->dentry))) {
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
+ return -ENOENT;
+ }
+ down_write(&namespace_sem);
+ mnt = lookup_mnt(path);
+ if (likely(!mnt))
+ return 0;
+ up_write(&namespace_sem);
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
+ path_put(path);
+ path->mnt = mnt;
+ path->dentry = dget(mnt->mnt_root);
+ goto retry;
+}
+
+static void unlock_mount(struct path *path)
+{
+ up_write(&namespace_sem);
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
+}
+
static int graft_tree(struct vfsmount *mnt, struct path *path)
{
- int err;
if (mnt->mnt_sb->s_flags & MS_NOUSER)
return -EINVAL;
S_ISDIR(mnt->mnt_root->d_inode->i_mode))
return -ENOTDIR;
- err = -ENOENT;
- mutex_lock(&path->dentry->d_inode->i_mutex);
- if (cant_mount(path->dentry))
- goto out_unlock;
+ if (d_unlinked(path->dentry))
+ return -ENOENT;
- if (!d_unlinked(path->dentry))
- err = attach_recursive_mnt(mnt, path, NULL);
-out_unlock:
- mutex_unlock(&path->dentry->d_inode->i_mutex);
- return err;
+ return attach_recursive_mnt(mnt, path, NULL);
}
/*
static int do_loopback(struct path *path, char *old_name,
int recurse)
{
+ LIST_HEAD(umount_list);
struct path old_path;
struct vfsmount *mnt = NULL;
int err = mount_is_safe(path);
if (err)
return err;
- down_write(&namespace_sem);
+ err = lock_mount(path);
+ if (err)
+ goto out;
+
err = -EINVAL;
if (IS_MNT_UNBINDABLE(old_path.mnt))
- goto out;
+ goto out2;
if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
- goto out;
+ goto out2;
err = -ENOMEM;
if (recurse)
mnt = clone_mnt(old_path.mnt, old_path.dentry, 0);
if (!mnt)
- goto out;
+ goto out2;
err = graft_tree(mnt, path);
if (err) {
- LIST_HEAD(umount_list);
-
br_write_lock(vfsmount_lock);
umount_tree(mnt, 0, &umount_list);
br_write_unlock(vfsmount_lock);
- release_mounts(&umount_list);
}
-
+out2:
+ unlock_mount(path);
+ release_mounts(&umount_list);
out:
- up_write(&namespace_sem);
path_put(&old_path);
return err;
}
if (err)
return err;
- down_write(&namespace_sem);
- err = follow_down(path, true);
+ err = lock_mount(path);
if (err < 0)
goto out;
err = -EINVAL;
if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
- goto out;
-
- err = -ENOENT;
- mutex_lock(&path->dentry->d_inode->i_mutex);
- if (cant_mount(path->dentry))
goto out1;
if (d_unlinked(path->dentry))
* automatically */
list_del_init(&old_path.mnt->mnt_expire);
out1:
- mutex_unlock(&path->dentry->d_inode->i_mutex);
+ unlock_mount(path);
out:
- up_write(&namespace_sem);
if (!err)
path_put(&parent_path);
path_put(&old_path);
return err;
}
-static int do_add_mount(struct vfsmount *, struct path *, int);
+static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
+{
+ int err;
+ const char *subtype = strchr(fstype, '.');
+ if (subtype) {
+ subtype++;
+ err = -EINVAL;
+ if (!subtype[0])
+ goto err;
+ } else
+ subtype = "";
+
+ mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
+ err = -ENOMEM;
+ if (!mnt->mnt_sb->s_subtype)
+ goto err;
+ return mnt;
+
+ err:
+ mntput(mnt);
+ return ERR_PTR(err);
+}
+
+struct vfsmount *
+do_kern_mount(const char *fstype, int flags, const char *name, void *data)
+{
+ struct file_system_type *type = get_fs_type(fstype);
+ struct vfsmount *mnt;
+ if (!type)
+ return ERR_PTR(-ENODEV);
+ mnt = vfs_kern_mount(type, flags, name, data);
+ if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
+ !mnt->mnt_sb->s_subtype)
+ mnt = fs_set_subtype(mnt, fstype);
+ put_filesystem(type);
+ return mnt;
+}
+EXPORT_SYMBOL_GPL(do_kern_mount);
+
+/*
+ * add a mount into a namespace's mount tree
+ */
+static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
+{
+ int err;
+
+ mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL);
+
+ err = lock_mount(path);
+ if (err)
+ return err;
+
+ err = -EINVAL;
+ if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
+ goto unlock;
+
+ /* Refuse the same filesystem on the same mount point */
+ err = -EBUSY;
+ if (path->mnt->mnt_sb == newmnt->mnt_sb &&
+ path->mnt->mnt_root == path->dentry)
+ goto unlock;
+
+ err = -EINVAL;
+ if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
+ goto unlock;
+
+ newmnt->mnt_flags = mnt_flags;
+ err = graft_tree(newmnt, path);
+
+unlock:
+ unlock_mount(path);
+ return err;
+}
/*
* create a new mount for userspace and request it to be added into the
return err;
}
-/*
- * add a mount into a namespace's mount tree
- */
-static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
-{
- int err;
-
- mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL);
-
- down_write(&namespace_sem);
- /* Something was mounted here while we slept */
- err = follow_down(path, true);
- if (err < 0)
- goto unlock;
-
- err = -EINVAL;
- if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
- goto unlock;
-
- /* Refuse the same filesystem on the same mount point */
- err = -EBUSY;
- if (path->mnt->mnt_sb == newmnt->mnt_sb &&
- path->mnt->mnt_root == path->dentry)
- goto unlock;
-
- err = -EINVAL;
- if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
- goto unlock;
-
- newmnt->mnt_flags = mnt_flags;
- err = graft_tree(newmnt, path);
-
-unlock:
- up_write(&namespace_sem);
- return err;
-}
-
/**
* mnt_set_expiry - Put a mount on an expiration list
* @mnt: The mount to list.
error = user_path_dir(new_root, &new);
if (error)
goto out0;
- error = -EINVAL;
- if (!check_mnt(new.mnt))
- goto out1;
error = user_path_dir(put_old, &old);
if (error)
goto out1;
error = security_sb_pivotroot(&old, &new);
- if (error) {
- path_put(&old);
- goto out1;
- }
+ if (error)
+ goto out2;
get_fs_root(current->fs, &root);
- down_write(&namespace_sem);
- mutex_lock(&old.dentry->d_inode->i_mutex);
+ error = lock_mount(&old);
+ if (error)
+ goto out3;
+
error = -EINVAL;
if (IS_MNT_SHARED(old.mnt) ||
IS_MNT_SHARED(new.mnt->mnt_parent) ||
IS_MNT_SHARED(root.mnt->mnt_parent))
- goto out2;
- if (!check_mnt(root.mnt))
- goto out2;
+ goto out4;
+ if (!check_mnt(root.mnt) || !check_mnt(new.mnt))
+ goto out4;
error = -ENOENT;
- if (cant_mount(old.dentry))
- goto out2;
if (d_unlinked(new.dentry))
- goto out2;
+ goto out4;
if (d_unlinked(old.dentry))
- goto out2;
+ goto out4;
error = -EBUSY;
if (new.mnt == root.mnt ||
old.mnt == root.mnt)
- goto out2; /* loop, on the same file system */
+ goto out4; /* loop, on the same file system */
error = -EINVAL;
if (root.mnt->mnt_root != root.dentry)
- goto out2; /* not a mountpoint */
+ goto out4; /* not a mountpoint */
if (root.mnt->mnt_parent == root.mnt)
- goto out2; /* not attached */
+ goto out4; /* not attached */
if (new.mnt->mnt_root != new.dentry)
- goto out2; /* not a mountpoint */
+ goto out4; /* not a mountpoint */
if (new.mnt->mnt_parent == new.mnt)
- goto out2; /* not attached */
+ goto out4; /* not attached */
/* make sure we can reach put_old from new_root */
tmp = old.mnt;
- br_write_lock(vfsmount_lock);
if (tmp != new.mnt) {
for (;;) {
if (tmp->mnt_parent == tmp)
- goto out3; /* already mounted on put_old */
+ goto out4; /* already mounted on put_old */
if (tmp->mnt_parent == new.mnt)
break;
tmp = tmp->mnt_parent;
}
if (!is_subdir(tmp->mnt_mountpoint, new.dentry))
- goto out3;
+ goto out4;
} else if (!is_subdir(old.dentry, new.dentry))
- goto out3;
+ goto out4;
+ br_write_lock(vfsmount_lock);
detach_mnt(new.mnt, &parent_path);
detach_mnt(root.mnt, &root_parent);
/* mount old root on put_old */
touch_mnt_namespace(current->nsproxy->mnt_ns);
br_write_unlock(vfsmount_lock);
chroot_fs_refs(&root, &new);
-
error = 0;
- path_put(&root_parent);
- path_put(&parent_path);
-out2:
- mutex_unlock(&old.dentry->d_inode->i_mutex);
- up_write(&namespace_sem);
+out4:
+ unlock_mount(&old);
+ if (!error) {
+ path_put(&root_parent);
+ path_put(&parent_path);
+ }
+out3:
path_put(&root);
+out2:
path_put(&old);
out1:
path_put(&new);
out0:
return error;
-out3:
- br_write_unlock(vfsmount_lock);
- goto out2;
}
static void __init init_mount_tree(void)
if (!mount_hashtable)
panic("Failed to allocate mount hash table\n");
- printk("Mount-cache hash table entries: %lu\n", HASH_SIZE);
+ printk(KERN_INFO "Mount-cache hash table entries: %lu\n", HASH_SIZE);
for (u = 0; u < HASH_SIZE; u++)
INIT_LIST_HEAD(&mount_hashtable[u]);
kfree(ns);
}
EXPORT_SYMBOL(put_mnt_ns);
+
+struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
+{
+ return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
+}
+EXPORT_SYMBOL_GPL(kern_mount_data);
git.openpandora.org / pandora-kernel.git / blobdiff