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