| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * loop.h |
| 3 | * |
| 4 | * Written by Theodore Ts'o, 3/29/93. |
| 5 | * |
| 6 | * Copyright 1993 by Theodore Ts'o. Redistribution of this file is |
| 7 | * permitted under the GNU General Public License. |
| 8 | */ |
| 9 | #ifndef _LINUX_LOOP_H |
| 10 | #define _LINUX_LOOP_H |
| 11 | |
| 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 <linux/kthread.h> |
| 18 | #include <uapi/linux/loop.h> |
| 19 | |
| 20 | /* Possible states of device */ |
| 21 | enum { |
| 22 | Lo_unbound, |
| 23 | Lo_bound, |
| 24 | Lo_rundown, |
| 25 | }; |
| 26 | |
| 27 | struct loop_func_table; |
| 28 | |
| 29 | struct loop_device { |
| 30 | int lo_number; |
| 31 | atomic_t lo_refcnt; |
| 32 | loff_t lo_offset; |
| 33 | loff_t lo_sizelimit; |
| 34 | int lo_flags; |
| 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; |
| 44 | __u32 lo_init[2]; |
| 45 | kuid_t lo_key_owner; /* Who set the key */ |
| 46 | int (*ioctl)(struct loop_device *, int cmd, |
| 47 | unsigned long arg); |
| 48 | |
| 49 | struct file * lo_backing_file; |
| 50 | struct block_device *lo_device; |
| 51 | void *key_data; |
| 52 | |
| 53 | gfp_t old_gfp_mask; |
| 54 | |
| 55 | spinlock_t lo_lock; |
| 56 | int lo_state; |
| 57 | struct mutex lo_ctl_mutex; |
| 58 | struct kthread_worker worker; |
| 59 | struct task_struct *worker_task; |
| 60 | bool use_dio; |
| 61 | bool sysfs_inited; |
| 62 | |
| 63 | struct request_queue *lo_queue; |
| 64 | struct blk_mq_tag_set tag_set; |
| 65 | struct gendisk *lo_disk; |
| 66 | }; |
| 67 | |
| 68 | struct loop_cmd { |
| 69 | struct kthread_work work; |
| 70 | struct request *rq; |
| 71 | bool use_aio; /* use AIO interface to handle I/O */ |
| 72 | atomic_t ref; /* only for aio */ |
| 73 | long ret; |
| 74 | struct kiocb iocb; |
| 75 | struct bio_vec *bvec; |
| 76 | }; |
| 77 | |
| 78 | /* Support for loadable transfer modules */ |
| 79 | struct loop_func_table { |
| 80 | int number; /* filter type */ |
| 81 | int (*transfer)(struct loop_device *lo, int cmd, |
| 82 | struct page *raw_page, unsigned raw_off, |
| 83 | struct page *loop_page, unsigned loop_off, |
| 84 | int size, sector_t real_block); |
| 85 | int (*init)(struct loop_device *, const struct loop_info64 *); |
| 86 | /* release is called from loop_unregister_transfer or clr_fd */ |
| 87 | int (*release)(struct loop_device *); |
| 88 | int (*ioctl)(struct loop_device *, int cmd, unsigned long arg); |
| 89 | struct module *owner; |
| 90 | }; |
| 91 | |
| 92 | int loop_register_transfer(struct loop_func_table *funcs); |
| 93 | int loop_unregister_transfer(int number); |
| 94 | |
| 95 | #endif |