xref: /openbmc/linux/drivers/md/dm-thin-metadata.h (revision 17b7d63f7ed10376e762fdfadbc65da6687d569a)
1991d9fa0SJoe Thornber /*
2991d9fa0SJoe Thornber  * Copyright (C) 2010-2011 Red Hat, Inc.
3991d9fa0SJoe Thornber  *
4991d9fa0SJoe Thornber  * This file is released under the GPL.
5991d9fa0SJoe Thornber  */
6991d9fa0SJoe Thornber 
7991d9fa0SJoe Thornber #ifndef DM_THIN_METADATA_H
8991d9fa0SJoe Thornber #define DM_THIN_METADATA_H
9991d9fa0SJoe Thornber 
10991d9fa0SJoe Thornber #include "persistent-data/dm-block-manager.h"
11991d9fa0SJoe Thornber 
12991d9fa0SJoe Thornber #define THIN_METADATA_BLOCK_SIZE 4096
13991d9fa0SJoe Thornber 
14c4a69ecdSMike Snitzer /*
15c4a69ecdSMike Snitzer  * The metadata device is currently limited in size.
16c4a69ecdSMike Snitzer  *
17c4a69ecdSMike Snitzer  * We have one block of index, which can hold 255 index entries.  Each
18c4a69ecdSMike Snitzer  * index entry contains allocation info about 16k metadata blocks.
19c4a69ecdSMike Snitzer  */
20c4a69ecdSMike Snitzer #define THIN_METADATA_MAX_SECTORS (255 * (1 << 14) * (THIN_METADATA_BLOCK_SIZE / (1 << SECTOR_SHIFT)))
21c4a69ecdSMike Snitzer 
22c4a69ecdSMike Snitzer /*
23c4a69ecdSMike Snitzer  * A metadata device larger than 16GB triggers a warning.
24c4a69ecdSMike Snitzer  */
25c4a69ecdSMike Snitzer #define THIN_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))
26c4a69ecdSMike Snitzer 
27991d9fa0SJoe Thornber /*----------------------------------------------------------------*/
28991d9fa0SJoe Thornber 
29991d9fa0SJoe Thornber struct dm_pool_metadata;
30991d9fa0SJoe Thornber struct dm_thin_device;
31991d9fa0SJoe Thornber 
32991d9fa0SJoe Thornber /*
33991d9fa0SJoe Thornber  * Device identifier
34991d9fa0SJoe Thornber  */
35991d9fa0SJoe Thornber typedef uint64_t dm_thin_id;
36991d9fa0SJoe Thornber 
37991d9fa0SJoe Thornber /*
38991d9fa0SJoe Thornber  * Reopens or creates a new, empty metadata volume.
39991d9fa0SJoe Thornber  */
40991d9fa0SJoe Thornber struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
41991d9fa0SJoe Thornber 					       sector_t data_block_size);
42991d9fa0SJoe Thornber 
43991d9fa0SJoe Thornber int dm_pool_metadata_close(struct dm_pool_metadata *pmd);
44991d9fa0SJoe Thornber 
45991d9fa0SJoe Thornber /*
46991d9fa0SJoe Thornber  * Compat feature flags.  Any incompat flags beyond the ones
47991d9fa0SJoe Thornber  * specified below will prevent use of the thin metadata.
48991d9fa0SJoe Thornber  */
49991d9fa0SJoe Thornber #define THIN_FEATURE_COMPAT_SUPP	  0UL
50991d9fa0SJoe Thornber #define THIN_FEATURE_COMPAT_RO_SUPP	  0UL
51991d9fa0SJoe Thornber #define THIN_FEATURE_INCOMPAT_SUPP	  0UL
52991d9fa0SJoe Thornber 
53991d9fa0SJoe Thornber /*
54991d9fa0SJoe Thornber  * Device creation/deletion.
55991d9fa0SJoe Thornber  */
56991d9fa0SJoe Thornber int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev);
57991d9fa0SJoe Thornber 
58991d9fa0SJoe Thornber /*
59991d9fa0SJoe Thornber  * An internal snapshot.
60991d9fa0SJoe Thornber  *
61991d9fa0SJoe Thornber  * You can only snapshot a quiesced origin i.e. one that is either
62991d9fa0SJoe Thornber  * suspended or not instanced at all.
63991d9fa0SJoe Thornber  */
64991d9fa0SJoe Thornber int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev,
65991d9fa0SJoe Thornber 			dm_thin_id origin);
66991d9fa0SJoe Thornber 
67991d9fa0SJoe Thornber /*
68991d9fa0SJoe Thornber  * Deletes a virtual device from the metadata.  It _is_ safe to call this
69991d9fa0SJoe Thornber  * when that device is open.  Operations on that device will just start
70991d9fa0SJoe Thornber  * failing.  You still need to call close() on the device.
71991d9fa0SJoe Thornber  */
72991d9fa0SJoe Thornber int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
73991d9fa0SJoe Thornber 			       dm_thin_id dev);
74991d9fa0SJoe Thornber 
75991d9fa0SJoe Thornber /*
76991d9fa0SJoe Thornber  * Commits _all_ metadata changes: device creation, deletion, mapping
77991d9fa0SJoe Thornber  * updates.
78991d9fa0SJoe Thornber  */
79991d9fa0SJoe Thornber int dm_pool_commit_metadata(struct dm_pool_metadata *pmd);
80991d9fa0SJoe Thornber 
81991d9fa0SJoe Thornber /*
82991d9fa0SJoe Thornber  * Set/get userspace transaction id.
83991d9fa0SJoe Thornber  */
84991d9fa0SJoe Thornber int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
85991d9fa0SJoe Thornber 					uint64_t current_id,
86991d9fa0SJoe Thornber 					uint64_t new_id);
87991d9fa0SJoe Thornber 
88991d9fa0SJoe Thornber int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
89991d9fa0SJoe Thornber 					uint64_t *result);
90991d9fa0SJoe Thornber 
91991d9fa0SJoe Thornber /*
92991d9fa0SJoe Thornber  * Hold/get root for userspace transaction.
93cc8394d8SJoe Thornber  *
94cc8394d8SJoe Thornber  * The metadata snapshot is a copy of the current superblock (minus the
95cc8394d8SJoe Thornber  * space maps).  Userland can access the data structures for READ
96cc8394d8SJoe Thornber  * operations only.  A small performance hit is incurred by providing this
97cc8394d8SJoe Thornber  * copy of the metadata to userland due to extra copy-on-write operations
98cc8394d8SJoe Thornber  * on the metadata nodes.  Release this as soon as you finish with it.
99991d9fa0SJoe Thornber  */
100cc8394d8SJoe Thornber int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd);
101cc8394d8SJoe Thornber int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd);
102991d9fa0SJoe Thornber 
103cc8394d8SJoe Thornber int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
104991d9fa0SJoe Thornber 			      dm_block_t *result);
105991d9fa0SJoe Thornber 
106991d9fa0SJoe Thornber /*
107991d9fa0SJoe Thornber  * Actions on a single virtual device.
108991d9fa0SJoe Thornber  */
109991d9fa0SJoe Thornber 
110991d9fa0SJoe Thornber /*
111991d9fa0SJoe Thornber  * Opening the same device more than once will fail with -EBUSY.
112991d9fa0SJoe Thornber  */
113991d9fa0SJoe Thornber int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
114991d9fa0SJoe Thornber 			     struct dm_thin_device **td);
115991d9fa0SJoe Thornber 
116991d9fa0SJoe Thornber int dm_pool_close_thin_device(struct dm_thin_device *td);
117991d9fa0SJoe Thornber 
118991d9fa0SJoe Thornber dm_thin_id dm_thin_dev_id(struct dm_thin_device *td);
119991d9fa0SJoe Thornber 
120991d9fa0SJoe Thornber struct dm_thin_lookup_result {
121991d9fa0SJoe Thornber 	dm_block_t block;
122*17b7d63fSMike Snitzer 	unsigned shared:1;
123991d9fa0SJoe Thornber };
124991d9fa0SJoe Thornber 
125991d9fa0SJoe Thornber /*
126991d9fa0SJoe Thornber  * Returns:
127991d9fa0SJoe Thornber  *   -EWOULDBLOCK iff @can_block is set and would block.
128991d9fa0SJoe Thornber  *   -ENODATA iff that mapping is not present.
129991d9fa0SJoe Thornber  *   0 success
130991d9fa0SJoe Thornber  */
131991d9fa0SJoe Thornber int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
132991d9fa0SJoe Thornber 		       int can_block, struct dm_thin_lookup_result *result);
133991d9fa0SJoe Thornber 
134991d9fa0SJoe Thornber /*
135991d9fa0SJoe Thornber  * Obtain an unused block.
136991d9fa0SJoe Thornber  */
137991d9fa0SJoe Thornber int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result);
138991d9fa0SJoe Thornber 
139991d9fa0SJoe Thornber /*
140991d9fa0SJoe Thornber  * Insert or remove block.
141991d9fa0SJoe Thornber  */
142991d9fa0SJoe Thornber int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
143991d9fa0SJoe Thornber 			 dm_block_t data_block);
144991d9fa0SJoe Thornber 
145991d9fa0SJoe Thornber int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);
146991d9fa0SJoe Thornber 
147991d9fa0SJoe Thornber /*
148991d9fa0SJoe Thornber  * Queries.
149991d9fa0SJoe Thornber  */
150991d9fa0SJoe Thornber int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
151991d9fa0SJoe Thornber 				     dm_block_t *highest_mapped);
152991d9fa0SJoe Thornber 
153991d9fa0SJoe Thornber int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result);
154991d9fa0SJoe Thornber 
155991d9fa0SJoe Thornber int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd,
156991d9fa0SJoe Thornber 				 dm_block_t *result);
157991d9fa0SJoe Thornber 
158991d9fa0SJoe Thornber int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
159991d9fa0SJoe Thornber 					  dm_block_t *result);
160991d9fa0SJoe Thornber 
161991d9fa0SJoe Thornber int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
162991d9fa0SJoe Thornber 				  dm_block_t *result);
163991d9fa0SJoe Thornber 
164991d9fa0SJoe Thornber int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result);
165991d9fa0SJoe Thornber 
166991d9fa0SJoe Thornber int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
167991d9fa0SJoe Thornber 
168991d9fa0SJoe Thornber /*
169991d9fa0SJoe Thornber  * Returns -ENOSPC if the new size is too small and already allocated
170991d9fa0SJoe Thornber  * blocks would be lost.
171991d9fa0SJoe Thornber  */
172991d9fa0SJoe Thornber int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
173991d9fa0SJoe Thornber 
174991d9fa0SJoe Thornber /*----------------------------------------------------------------*/
175991d9fa0SJoe Thornber 
176991d9fa0SJoe Thornber #endif
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