aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/dm-io.h
diff options
context:
space:
mode:
authorAlasdair G Kergon <agk@redhat.com>2008-04-24 17:02:01 -0400
committerAlasdair G Kergon <agk@redhat.com>2008-04-25 08:26:55 -0400
commita765e20eeb423d0fa6a02ffab51141e53bbd93cb (patch)
treefc7279fa73a21518373e1ba2efad27dab89a2214 /include/linux/dm-io.h
parent2d1e580afe23287871529ce54429e249809525a1 (diff)
dm: move include files
Publish the dm-io, dm-log and dm-kcopyd headers in include/linux. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'include/linux/dm-io.h')
-rw-r--r--include/linux/dm-io.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h
new file mode 100644
index 000000000000..b6bf17ee2f61
--- /dev/null
+++ b/include/linux/dm-io.h
@@ -0,0 +1,85 @@
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_BVEC, /* 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 union {
41 struct page_list *pl;
42 struct bio_vec *bvec;
43 void *vma;
44 void *addr;
45 } ptr;
46
47 unsigned offset;
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_rw; /* READ|WRITE - not READA */
61 struct dm_io_memory mem; /* Memory to use for io */
62 struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
63 struct dm_io_client *client; /* Client memory handler */
64};
65
66/*
67 * For async io calls, users can alternatively use the dm_io() function below
68 * and dm_io_client_create() to create private mempools for the client.
69 *
70 * Create/destroy may block.
71 */
72struct dm_io_client *dm_io_client_create(unsigned num_pages);
73int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client);
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 */