| /* |
| * 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, |
| Lo_deleting, |
| }; |
| |
| 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 kthread_worker worker; |
| struct task_struct *worker_task; |
| bool use_dio; |
| bool sysfs_inited; |
| |
| struct request_queue *lo_queue; |
| struct blk_mq_tag_set tag_set; |
| struct gendisk *lo_disk; |
| struct mutex lo_mutex; |
| }; |
| |
| struct loop_cmd { |
| struct kthread_work work; |
| 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 |