1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * loop.h 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Written by Theodore Ts'o, 3/29/93. 5*4882a593Smuzhiyun * 6*4882a593Smuzhiyun * Copyright 1993 by Theodore Ts'o. Redistribution of this file is 7*4882a593Smuzhiyun * permitted under the GNU General Public License. 8*4882a593Smuzhiyun */ 9*4882a593Smuzhiyun #ifndef _LINUX_LOOP_H 10*4882a593Smuzhiyun #define _LINUX_LOOP_H 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun #include <linux/bio.h> 13*4882a593Smuzhiyun #include <linux/blkdev.h> 14*4882a593Smuzhiyun #include <linux/blk-mq.h> 15*4882a593Smuzhiyun #include <linux/spinlock.h> 16*4882a593Smuzhiyun #include <linux/mutex.h> 17*4882a593Smuzhiyun #include <linux/kthread.h> 18*4882a593Smuzhiyun #include <uapi/linux/loop.h> 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun /* Possible states of device */ 21*4882a593Smuzhiyun enum { 22*4882a593Smuzhiyun Lo_unbound, 23*4882a593Smuzhiyun Lo_bound, 24*4882a593Smuzhiyun Lo_rundown, 25*4882a593Smuzhiyun }; 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun struct loop_func_table; 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun struct loop_device { 30*4882a593Smuzhiyun int lo_number; 31*4882a593Smuzhiyun atomic_t lo_refcnt; 32*4882a593Smuzhiyun loff_t lo_offset; 33*4882a593Smuzhiyun loff_t lo_sizelimit; 34*4882a593Smuzhiyun int lo_flags; 35*4882a593Smuzhiyun int (*transfer)(struct loop_device *, int cmd, 36*4882a593Smuzhiyun struct page *raw_page, unsigned raw_off, 37*4882a593Smuzhiyun struct page *loop_page, unsigned loop_off, 38*4882a593Smuzhiyun int size, sector_t real_block); 39*4882a593Smuzhiyun char lo_file_name[LO_NAME_SIZE]; 40*4882a593Smuzhiyun char lo_crypt_name[LO_NAME_SIZE]; 41*4882a593Smuzhiyun char lo_encrypt_key[LO_KEY_SIZE]; 42*4882a593Smuzhiyun int lo_encrypt_key_size; 43*4882a593Smuzhiyun struct loop_func_table *lo_encryption; 44*4882a593Smuzhiyun __u32 lo_init[2]; 45*4882a593Smuzhiyun kuid_t lo_key_owner; /* Who set the key */ 46*4882a593Smuzhiyun int (*ioctl)(struct loop_device *, int cmd, 47*4882a593Smuzhiyun unsigned long arg); 48*4882a593Smuzhiyun 49*4882a593Smuzhiyun struct file * lo_backing_file; 50*4882a593Smuzhiyun struct block_device *lo_device; 51*4882a593Smuzhiyun void *key_data; 52*4882a593Smuzhiyun 53*4882a593Smuzhiyun gfp_t old_gfp_mask; 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun spinlock_t lo_lock; 56*4882a593Smuzhiyun int lo_state; 57*4882a593Smuzhiyun struct kthread_worker worker; 58*4882a593Smuzhiyun struct task_struct *worker_task; 59*4882a593Smuzhiyun bool use_dio; 60*4882a593Smuzhiyun bool sysfs_inited; 61*4882a593Smuzhiyun 62*4882a593Smuzhiyun struct request_queue *lo_queue; 63*4882a593Smuzhiyun struct blk_mq_tag_set tag_set; 64*4882a593Smuzhiyun struct gendisk *lo_disk; 65*4882a593Smuzhiyun }; 66*4882a593Smuzhiyun 67*4882a593Smuzhiyun struct loop_cmd { 68*4882a593Smuzhiyun struct kthread_work work; 69*4882a593Smuzhiyun bool use_aio; /* use AIO interface to handle I/O */ 70*4882a593Smuzhiyun atomic_t ref; /* only for aio */ 71*4882a593Smuzhiyun long ret; 72*4882a593Smuzhiyun struct kiocb iocb; 73*4882a593Smuzhiyun struct bio_vec *bvec; 74*4882a593Smuzhiyun struct cgroup_subsys_state *css; 75*4882a593Smuzhiyun }; 76*4882a593Smuzhiyun 77*4882a593Smuzhiyun /* Support for loadable transfer modules */ 78*4882a593Smuzhiyun struct loop_func_table { 79*4882a593Smuzhiyun int number; /* filter type */ 80*4882a593Smuzhiyun int (*transfer)(struct loop_device *lo, int cmd, 81*4882a593Smuzhiyun struct page *raw_page, unsigned raw_off, 82*4882a593Smuzhiyun struct page *loop_page, unsigned loop_off, 83*4882a593Smuzhiyun int size, sector_t real_block); 84*4882a593Smuzhiyun int (*init)(struct loop_device *, const struct loop_info64 *); 85*4882a593Smuzhiyun /* release is called from loop_unregister_transfer or clr_fd */ 86*4882a593Smuzhiyun int (*release)(struct loop_device *); 87*4882a593Smuzhiyun int (*ioctl)(struct loop_device *, int cmd, unsigned long arg); 88*4882a593Smuzhiyun struct module *owner; 89*4882a593Smuzhiyun }; 90*4882a593Smuzhiyun 91*4882a593Smuzhiyun int loop_register_transfer(struct loop_func_table *funcs); 92*4882a593Smuzhiyun int loop_unregister_transfer(int number); 93*4882a593Smuzhiyun 94*4882a593Smuzhiyun #endif 95