1/*
 2 * Copyright (C) 2003 Sistina Software
 3 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
 4 *
 5 * Device-Mapper low-level I/O.
 6 *
 7 * This file is released under the GPL.
 8 */
 9
10#ifndef _LINUX_DM_IO_H
11#define _LINUX_DM_IO_H
12
13#ifdef __KERNEL__
14
15#include <linux/types.h>
 
16
17struct dm_io_region {
18	struct block_device *bdev;
19	sector_t sector;
20	sector_t count;		/* If this is zero the region is ignored. */
21};
22
23struct page_list {
24	struct page_list *next;
25	struct page *page;
26};
27
28typedef void (*io_notify_fn)(unsigned long error, void *context);
29
30enum dm_io_mem_type {
31	DM_IO_PAGE_LIST,/* Page list */
32	DM_IO_BIO,	/* Bio vector */
33	DM_IO_VMA,	/* Virtual memory area */
34	DM_IO_KMEM,	/* Kernel memory */
35};
36
37struct dm_io_memory {
38	enum dm_io_mem_type type;
39
40	unsigned offset;
41
42	union {
43		struct page_list *pl;
44		struct bio *bio;
45		void *vma;
46		void *addr;
47	} ptr;
48};
49
50struct dm_io_notify {
51	io_notify_fn fn;	/* Callback for asynchronous requests */
52	void *context;		/* Passed to callback */
53};
54
55/*
56 * IO request structure
57 */
58struct dm_io_client;
59struct dm_io_request {
60	int bi_op;			/* REQ_OP */
61	int bi_op_flags;		/* req_flag_bits */
62	struct dm_io_memory mem;	/* Memory to use for io */
63	struct dm_io_notify notify;	/* Synchronous if notify.fn is NULL */
64	struct dm_io_client *client;	/* Client memory handler */
65};
66
67/*
68 * For async io calls, users can alternatively use the dm_io() function below
69 * and dm_io_client_create() to create private mempools for the client.
70 *
71 * Create/destroy may block.
72 */
73struct dm_io_client *dm_io_client_create(void);
74void dm_io_client_destroy(struct dm_io_client *client);
75
76/*
77 * IO interface using private per-client pools.
78 * Each bit in the optional 'sync_error_bits' bitset indicates whether an
79 * error occurred doing io to the corresponding region.
80 */
81int dm_io(struct dm_io_request *io_req, unsigned num_regions,
82	  struct dm_io_region *region, unsigned long *sync_error_bits);
83
84#endif	/* __KERNEL__ */
85#endif	/* _LINUX_DM_IO_H */

 1/*
 2 * Copyright (C) 2003 Sistina Software
 3 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
 4 *
 5 * Device-Mapper low-level I/O.
 6 *
 7 * This file is released under the GPL.
 8 */
 9
10#ifndef _LINUX_DM_IO_H
11#define _LINUX_DM_IO_H
12
13#ifdef __KERNEL__
14
15#include <linux/types.h>
16#include <linux/blk_types.h>
17
18struct dm_io_region {
19	struct block_device *bdev;
20	sector_t sector;
21	sector_t count;		/* If this is zero the region is ignored. */
22};
23
24struct page_list {
25	struct page_list *next;
26	struct page *page;
27};
28
29typedef void (*io_notify_fn)(unsigned long error, void *context);
30
31enum dm_io_mem_type {
32	DM_IO_PAGE_LIST,/* Page list */
33	DM_IO_BIO,	/* Bio vector */
34	DM_IO_VMA,	/* Virtual memory area */
35	DM_IO_KMEM,	/* Kernel memory */
36};
37
38struct dm_io_memory {
39	enum dm_io_mem_type type;
40
41	unsigned offset;
42
43	union {
44		struct page_list *pl;
45		struct bio *bio;
46		void *vma;
47		void *addr;
48	} ptr;
49};
50
51struct dm_io_notify {
52	io_notify_fn fn;	/* Callback for asynchronous requests */
53	void *context;		/* Passed to callback */
54};
55
56/*
57 * IO request structure
58 */
59struct dm_io_client;
60struct dm_io_request {
61	blk_opf_t	    bi_opf;	/* Request type and flags */
 
62	struct dm_io_memory mem;	/* Memory to use for io */
63	struct dm_io_notify notify;	/* Synchronous if notify.fn is NULL */
64	struct dm_io_client *client;	/* Client memory handler */
65};
66
67/*
68 * For async io calls, users can alternatively use the dm_io() function below
69 * and dm_io_client_create() to create private mempools for the client.
70 *
71 * Create/destroy may block.
72 */
73struct dm_io_client *dm_io_client_create(void);
74void dm_io_client_destroy(struct dm_io_client *client);
75
76/*
77 * IO interface using private per-client pools.
78 * Each bit in the optional 'sync_error_bits' bitset indicates whether an
79 * error occurred doing io to the corresponding region.
80 */
81int dm_io(struct dm_io_request *io_req, unsigned num_regions,
82	  struct dm_io_region *region, unsigned long *sync_error_bits);
83
84#endif	/* __KERNEL__ */
85#endif	/* _LINUX_DM_IO_H */