blob: a52c6580cc9a93330d9c2fd6d0a3ed25da3b2451 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*
* Copyright (C) 2003 Sistina Software
* Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
*
* Device-Mapper low-level I/O.
*
* This file is released under the GPL.
*/
#ifndef _LINUX_DM_IO_H
#define _LINUX_DM_IO_H
#ifdef __KERNEL__
#include <linux/types.h>
struct dm_io_region {
struct block_device *bdev;
sector_t sector;
sector_t count; /* If this is zero the region is ignored. */
};
struct page_list {
struct page_list *next;
struct page *page;
};
typedef void (*io_notify_fn)(unsigned long error, void *context);
enum dm_io_mem_type {
DM_IO_PAGE_LIST,/* Page list */
DM_IO_BIO, /* Bio vector */
DM_IO_VMA, /* Virtual memory area */
DM_IO_KMEM, /* Kernel memory */
};
struct dm_io_memory {
enum dm_io_mem_type type;
unsigned offset;
union {
struct page_list *pl;
struct bio *bio;
void *vma;
void *addr;
} ptr;
};
struct dm_io_notify {
io_notify_fn fn; /* Callback for asynchronous requests */
void *context; /* Passed to callback */
};
/*
* IO request structure
*/
struct dm_io_client;
struct dm_io_request {
int bi_op; /* REQ_OP */
int bi_op_flags; /* req_flag_bits */
struct dm_io_memory mem; /* Memory to use for io */
struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
struct dm_io_client *client; /* Client memory handler */
};
/*
* For async io calls, users can alternatively use the dm_io() function below
* and dm_io_client_create() to create private mempools for the client.
*
* Create/destroy may block.
*/
struct dm_io_client *dm_io_client_create(void);
void dm_io_client_destroy(struct dm_io_client *client);
/*
* IO interface using private per-client pools.
* Each bit in the optional 'sync_error_bits' bitset indicates whether an
* error occurred doing io to the corresponding region.
*/
int dm_io(struct dm_io_request *io_req, unsigned num_regions,
struct dm_io_region *region, unsigned long *sync_error_bits);
#endif /* __KERNEL__ */
#endif /* _LINUX_DM_IO_H */
|
