- * find_or_create_nilfs - find or create nilfs object
- * @bdev: block device to which the_nilfs is related
- *
- * find_nilfs() looks up an existent nilfs object created on the
- * device and gets the reference count of the object. If no nilfs object
- * is found on the device, a new nilfs object is allocated.
- *
- * Return Value: On success, pointer to the nilfs object is returned.
- * On error, NULL is returned.
- */
-struct the_nilfs *find_or_create_nilfs(struct block_device *bdev)
-{
- struct the_nilfs *nilfs, *new = NULL;
-
- retry:
- spin_lock(&nilfs_lock);
- list_for_each_entry(nilfs, &nilfs_objects, ns_list) {
- if (nilfs->ns_bdev == bdev) {
- get_nilfs(nilfs);
- spin_unlock(&nilfs_lock);
- if (new)
- put_nilfs(new);
- return nilfs; /* existing object */
- }
- }
- if (new) {
- list_add_tail(&new->ns_list, &nilfs_objects);
- spin_unlock(&nilfs_lock);
- return new; /* new object */
- }
- spin_unlock(&nilfs_lock);
-
- new = alloc_nilfs(bdev);
- if (new)
- goto retry;
- return NULL; /* insufficient memory */
-}
-
-/**
- * put_nilfs - release a reference to the_nilfs
- * @nilfs: the_nilfs structure to be released
- *
- * put_nilfs() decrements a reference counter of the_nilfs.
- * If the reference count reaches zero, the_nilfs is freed.