4 * Written by Theodore Ts'o, 3/29/93.
6 * Copyright 1993 by Theodore Ts'o. Redistribution of this file is
7 * permitted under the GNU General Public License.
12 #include <linux/bio.h>
13 #include <linux/blkdev.h>
14 #include <linux/blk-mq.h>
15 #include <linux/spinlock.h>
16 #include <linux/mutex.h>
17 #include <uapi/linux/loop.h>
19 /* Possible states of device */
27 struct loop_func_table;
35 int (*transfer)(struct loop_device *, int cmd,
36 struct page *raw_page, unsigned raw_off,
37 struct page *loop_page, unsigned loop_off,
38 int size, sector_t real_block);
39 char lo_file_name[LO_NAME_SIZE];
40 char lo_crypt_name[LO_NAME_SIZE];
41 char lo_encrypt_key[LO_KEY_SIZE];
42 int lo_encrypt_key_size;
43 struct loop_func_table *lo_encryption;
45 kuid_t lo_key_owner; /* Who set the key */
46 int (*ioctl)(struct loop_device *, int cmd,
49 struct file * lo_backing_file;
50 struct block_device *lo_device;
57 spinlock_t lo_work_lock;
58 struct workqueue_struct *workqueue;
59 struct work_struct rootcg_work;
60 struct list_head rootcg_cmd_list;
61 struct list_head idle_worker_list;
62 struct rb_root worker_tree;
63 struct timer_list timer;
67 struct request_queue *lo_queue;
68 struct blk_mq_tag_set tag_set;
69 struct gendisk *lo_disk;
70 struct mutex lo_mutex;
75 struct list_head list_entry;
76 bool use_aio; /* use AIO interface to handle I/O */
77 atomic_t ref; /* only for aio */
81 struct cgroup_subsys_state *blkcg_css;
82 struct cgroup_subsys_state *memcg_css;
85 /* Support for loadable transfer modules */
86 struct loop_func_table {
87 int number; /* filter type */
88 int (*transfer)(struct loop_device *lo, int cmd,
89 struct page *raw_page, unsigned raw_off,
90 struct page *loop_page, unsigned loop_off,
91 int size, sector_t real_block);
92 int (*init)(struct loop_device *, const struct loop_info64 *);
93 /* release is called from loop_unregister_transfer or clr_fd */
94 int (*release)(struct loop_device *);
95 int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
99 int loop_register_transfer(struct loop_func_table *funcs);
100 int loop_unregister_transfer(int number);