1 /* SPDX-License-Identifier: GPL-2.0-only */ 1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* 2 /*
3 * Copyright (C) 2003 Sistina Software 3 * Copyright (C) 2003 Sistina Software
4 * Copyright (C) 2004 - 2008 Red Hat, Inc. All 4 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
5 * 5 *
6 * Device-Mapper low-level I/O. 6 * Device-Mapper low-level I/O.
7 * 7 *
8 * This file is released under the GPL. 8 * This file is released under the GPL.
9 */ 9 */
10 10
11 #ifndef _LINUX_DM_IO_H 11 #ifndef _LINUX_DM_IO_H
12 #define _LINUX_DM_IO_H 12 #define _LINUX_DM_IO_H
13 13
14 #ifdef __KERNEL__ 14 #ifdef __KERNEL__
15 15
16 #include <linux/types.h> 16 #include <linux/types.h>
17 #include <linux/blk_types.h> 17 #include <linux/blk_types.h>
18 18
19 struct dm_io_region { 19 struct dm_io_region {
20 struct block_device *bdev; 20 struct block_device *bdev;
21 sector_t sector; 21 sector_t sector;
22 sector_t count; /* If this is 22 sector_t count; /* If this is zero the region is ignored. */
23 }; 23 };
24 24
25 struct page_list { 25 struct page_list {
26 struct page_list *next; 26 struct page_list *next;
27 struct page *page; 27 struct page *page;
28 }; 28 };
29 29
30 typedef void (*io_notify_fn)(unsigned int long 30 typedef void (*io_notify_fn)(unsigned int long error, void *context);
31 31
32 enum dm_io_mem_type { 32 enum dm_io_mem_type {
33 DM_IO_PAGE_LIST,/* Page list */ 33 DM_IO_PAGE_LIST,/* Page list */
34 DM_IO_BIO, /* Bio vector */ 34 DM_IO_BIO, /* Bio vector */
35 DM_IO_VMA, /* Virtual memory area 35 DM_IO_VMA, /* Virtual memory area */
36 DM_IO_KMEM, /* Kernel memory */ 36 DM_IO_KMEM, /* Kernel memory */
37 }; 37 };
38 38
39 struct dm_io_memory { 39 struct dm_io_memory {
40 enum dm_io_mem_type type; 40 enum dm_io_mem_type type;
41 41
42 unsigned int offset; 42 unsigned int offset;
43 43
44 union { 44 union {
45 struct page_list *pl; 45 struct page_list *pl;
46 struct bio *bio; 46 struct bio *bio;
47 void *vma; 47 void *vma;
48 void *addr; 48 void *addr;
49 } ptr; 49 } ptr;
50 }; 50 };
51 51
52 struct dm_io_notify { 52 struct dm_io_notify {
53 io_notify_fn fn; /* Callback fo 53 io_notify_fn fn; /* Callback for asynchronous requests */
54 void *context; /* Passed to c 54 void *context; /* Passed to callback */
55 }; 55 };
56 56
57 /* 57 /*
58 * IO request structure 58 * IO request structure
59 */ 59 */
60 struct dm_io_client; 60 struct dm_io_client;
61 struct dm_io_request { 61 struct dm_io_request {
62 blk_opf_t bi_opf; /* Req 62 blk_opf_t bi_opf; /* Request type and flags */
63 struct dm_io_memory mem; /* Mem 63 struct dm_io_memory mem; /* Memory to use for io */
64 struct dm_io_notify notify; /* Syn 64 struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
65 struct dm_io_client *client; /* Cli 65 struct dm_io_client *client; /* Client memory handler */
66 }; 66 };
67 67
68 /* 68 /*
69 * For async io calls, users can alternatively 69 * For async io calls, users can alternatively use the dm_io() function below
70 * and dm_io_client_create() to create private 70 * and dm_io_client_create() to create private mempools for the client.
71 * 71 *
72 * Create/destroy may block. 72 * Create/destroy may block.
73 */ 73 */
74 struct dm_io_client *dm_io_client_create(void) 74 struct dm_io_client *dm_io_client_create(void);
75 void dm_io_client_destroy(struct dm_io_client 75 void dm_io_client_destroy(struct dm_io_client *client);
76 76
77 /* 77 /*
78 * IO interface using private per-client pools 78 * IO interface using private per-client pools.
79 * Each bit in the optional 'sync_error_bits' 79 * Each bit in the optional 'sync_error_bits' bitset indicates whether an
80 * error occurred doing io to the correspondin 80 * error occurred doing io to the corresponding region.
81 */ 81 */
82 int dm_io(struct dm_io_request *io_req, unsign 82 int dm_io(struct dm_io_request *io_req, unsigned int num_regions,
83 struct dm_io_region *region, unsigne 83 struct dm_io_region *region, unsigned int long *sync_error_bits,
84 unsigned short ioprio); 84 unsigned short ioprio);
85 85
86 #endif /* __KERNEL__ */ 86 #endif /* __KERNEL__ */
87 #endif /* _LINUX_DM_IO_H */ 87 #endif /* _LINUX_DM_IO_H */
88 88
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