diff options
author | Jonathan Brassow <jbrassow@redhat.com> | 2009-01-05 22:05:15 -0500 |
---|---|---|
committer | Alasdair G Kergon <agk@redhat.com> | 2009-01-05 22:05:15 -0500 |
commit | aea53d92f70eeb00ae480e399a997dd55fd5055d (patch) | |
tree | 55e087e5e22168ed87f6d51ca0c8557a7678834f /drivers/md/dm-snap.h | |
parent | fe9cf30eb8186ef267d1868dc9f12f2d0f40835a (diff) |
dm snapshot: separate out exception store interface
Pull structures that bridge the gap between snapshot and
exception store out of dm-snap.h and put them in a new
.h file - dm-exception-store.h. This file will define the
API for new exception stores.
Ultimately, dm-snap.h is unnecessary, since only dm-snap.c
should be using it.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-snap.h')
-rw-r--r-- | drivers/md/dm-snap.h | 121 |
1 files changed, 1 insertions, 120 deletions
diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h index 99c0106ede2d..6e4beaf89f6c 100644 --- a/drivers/md/dm-snap.h +++ b/drivers/md/dm-snap.h | |||
@@ -1,6 +1,4 @@ | |||
1 | /* | 1 | /* |
2 | * dm-snapshot.c | ||
3 | * | ||
4 | * Copyright (C) 2001-2002 Sistina Software (UK) Limited. | 2 | * Copyright (C) 2001-2002 Sistina Software (UK) Limited. |
5 | * | 3 | * |
6 | * This file is released under the GPL. | 4 | * This file is released under the GPL. |
@@ -10,6 +8,7 @@ | |||
10 | #define DM_SNAPSHOT_H | 8 | #define DM_SNAPSHOT_H |
11 | 9 | ||
12 | #include <linux/device-mapper.h> | 10 | #include <linux/device-mapper.h> |
11 | #include "dm-exception-store.h" | ||
13 | #include "dm-bio-list.h" | 12 | #include "dm-bio-list.h" |
14 | #include <linux/blkdev.h> | 13 | #include <linux/blkdev.h> |
15 | #include <linux/workqueue.h> | 14 | #include <linux/workqueue.h> |
@@ -20,116 +19,6 @@ struct exception_table { | |||
20 | struct list_head *table; | 19 | struct list_head *table; |
21 | }; | 20 | }; |
22 | 21 | ||
23 | /* | ||
24 | * The snapshot code deals with largish chunks of the disk at a | ||
25 | * time. Typically 32k - 512k. | ||
26 | */ | ||
27 | typedef sector_t chunk_t; | ||
28 | |||
29 | /* | ||
30 | * An exception is used where an old chunk of data has been | ||
31 | * replaced by a new one. | ||
32 | * If chunk_t is 64 bits in size, the top 8 bits of new_chunk hold the number | ||
33 | * of chunks that follow contiguously. Remaining bits hold the number of the | ||
34 | * chunk within the device. | ||
35 | */ | ||
36 | struct dm_snap_exception { | ||
37 | struct list_head hash_list; | ||
38 | |||
39 | chunk_t old_chunk; | ||
40 | chunk_t new_chunk; | ||
41 | }; | ||
42 | |||
43 | /* | ||
44 | * Funtions to manipulate consecutive chunks | ||
45 | */ | ||
46 | # if defined(CONFIG_LBD) || (BITS_PER_LONG == 64) | ||
47 | # define DM_CHUNK_CONSECUTIVE_BITS 8 | ||
48 | # define DM_CHUNK_NUMBER_BITS 56 | ||
49 | |||
50 | static inline chunk_t dm_chunk_number(chunk_t chunk) | ||
51 | { | ||
52 | return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL); | ||
53 | } | ||
54 | |||
55 | static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e) | ||
56 | { | ||
57 | return e->new_chunk >> DM_CHUNK_NUMBER_BITS; | ||
58 | } | ||
59 | |||
60 | static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e) | ||
61 | { | ||
62 | e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS); | ||
63 | |||
64 | BUG_ON(!dm_consecutive_chunk_count(e)); | ||
65 | } | ||
66 | |||
67 | # else | ||
68 | # define DM_CHUNK_CONSECUTIVE_BITS 0 | ||
69 | |||
70 | static inline chunk_t dm_chunk_number(chunk_t chunk) | ||
71 | { | ||
72 | return chunk; | ||
73 | } | ||
74 | |||
75 | static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e) | ||
76 | { | ||
77 | return 0; | ||
78 | } | ||
79 | |||
80 | static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e) | ||
81 | { | ||
82 | } | ||
83 | |||
84 | # endif | ||
85 | |||
86 | /* | ||
87 | * Abstraction to handle the meta/layout of exception stores (the | ||
88 | * COW device). | ||
89 | */ | ||
90 | struct exception_store { | ||
91 | |||
92 | /* | ||
93 | * Destroys this object when you've finished with it. | ||
94 | */ | ||
95 | void (*destroy) (struct exception_store *store); | ||
96 | |||
97 | /* | ||
98 | * The target shouldn't read the COW device until this is | ||
99 | * called. | ||
100 | */ | ||
101 | int (*read_metadata) (struct exception_store *store); | ||
102 | |||
103 | /* | ||
104 | * Find somewhere to store the next exception. | ||
105 | */ | ||
106 | int (*prepare_exception) (struct exception_store *store, | ||
107 | struct dm_snap_exception *e); | ||
108 | |||
109 | /* | ||
110 | * Update the metadata with this exception. | ||
111 | */ | ||
112 | void (*commit_exception) (struct exception_store *store, | ||
113 | struct dm_snap_exception *e, | ||
114 | void (*callback) (void *, int success), | ||
115 | void *callback_context); | ||
116 | |||
117 | /* | ||
118 | * The snapshot is invalid, note this in the metadata. | ||
119 | */ | ||
120 | void (*drop_snapshot) (struct exception_store *store); | ||
121 | |||
122 | /* | ||
123 | * Return how full the snapshot is. | ||
124 | */ | ||
125 | void (*fraction_full) (struct exception_store *store, | ||
126 | sector_t *numerator, | ||
127 | sector_t *denominator); | ||
128 | |||
129 | struct dm_snapshot *snap; | ||
130 | void *context; | ||
131 | }; | ||
132 | |||
133 | #define DM_TRACKED_CHUNK_HASH_SIZE 16 | 22 | #define DM_TRACKED_CHUNK_HASH_SIZE 16 |
134 | #define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \ | 23 | #define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \ |
135 | (DM_TRACKED_CHUNK_HASH_SIZE - 1)) | 24 | (DM_TRACKED_CHUNK_HASH_SIZE - 1)) |
@@ -193,14 +82,6 @@ struct dm_snapshot { | |||
193 | int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new); | 82 | int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new); |
194 | 83 | ||
195 | /* | 84 | /* |
196 | * Constructor and destructor for the default persistent | ||
197 | * store. | ||
198 | */ | ||
199 | int dm_create_persistent(struct exception_store *store); | ||
200 | |||
201 | int dm_create_transient(struct exception_store *store); | ||
202 | |||
203 | /* | ||
204 | * Return the number of sectors in the device. | 85 | * Return the number of sectors in the device. |
205 | */ | 86 | */ |
206 | static inline sector_t get_dev_size(struct block_device *bdev) | 87 | static inline sector_t get_dev_size(struct block_device *bdev) |