/* * loop.h * * Written by Theodore Ts'o, 3/29/93. * * Copyright 1993 by Theodore Ts'o. Redistribution of this file is * permitted under the GNU General Public License. */ #ifndef _LINUX_LOOP_H #define _LINUX_LOOP_H #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/blk-mq.h> #include <linux/spinlock.h> #include <linux/mutex.h> #include <linux/kthread.h> #include <uapi/linux/loop.h> /* Possible states of device */ enum { Lo_unbound, Lo_bound, Lo_rundown, }; struct loop_func_table; struct loop_device { int lo_number; atomic_t lo_refcnt; loff_t lo_offset; loff_t lo_sizelimit; int lo_flags; int (*transfer)(struct loop_device *, int cmd, struct page *raw_page, unsigned raw_off, struct page *loop_page, unsigned loop_off, int size, sector_t real_block); char lo_file_name[LO_NAME_SIZE]; char lo_crypt_name[LO_NAME_SIZE]; char lo_encrypt_key[LO_KEY_SIZE]; int lo_encrypt_key_size; struct loop_func_table *lo_encryption; __u32 lo_init[2]; kuid_t lo_key_owner; /* Who set the key */ int (*ioctl)(struct loop_device *, int cmd, unsigned long arg); struct file * lo_backing_file; struct block_device *lo_device; void *key_data; gfp_t old_gfp_mask; spinlock_t lo_lock; int lo_state; struct mutex lo_ctl_mutex; struct kthread_worker worker; struct task_struct *worker_task; bool use_dio; struct request_queue *lo_queue; struct blk_mq_tag_set tag_set; struct gendisk *lo_disk; }; struct loop_cmd { struct kthread_work work; struct request *rq; bool use_aio; /* use AIO interface to handle I/O */ atomic_t ref; /* only for aio */ long ret; struct kiocb iocb; struct bio_vec *bvec; struct cgroup_subsys_state *css; }; /* Support for loadable transfer modules */ struct loop_func_table { int number; /* filter type */ int (*transfer)(struct loop_device *lo, int cmd, struct page *raw_page, unsigned raw_off, struct page *loop_page, unsigned loop_off, int size, sector_t real_block); int (*init)(struct loop_device *, const struct loop_info64 *); /* release is called from loop_unregister_transfer or clr_fd */ int (*release)(struct loop_device *); int (*ioctl)(struct loop_device *, int cmd, unsigned long arg); struct module *owner; }; int loop_register_transfer(struct loop_func_table *funcs); int loop_unregister_transfer(int number); #endif