[mirror_ubuntu-artful-kernel.git] / drivers / md / dm-thin-metadata.h

/*
 * Copyright (C) 2010-2011 Red Hat, Inc.
 *
 * This file is released under the GPL.
 */

#ifndef DM_THIN_METADATA_H
#define DM_THIN_METADATA_H

#include "persistent-data/dm-block-manager.h"

#define THIN_METADATA_BLOCK_SIZE 4096

/*----------------------------------------------------------------*/

struct dm_pool_metadata;
struct dm_thin_device;

/*
 * Device identifier
 */
typedef uint64_t dm_thin_id;

/*
 * Reopens or creates a new, empty metadata volume.
 */
struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
					       sector_t data_block_size);

int dm_pool_metadata_close(struct dm_pool_metadata *pmd);

/*
 * Compat feature flags.  Any incompat flags beyond the ones
 * specified below will prevent use of the thin metadata.
 */
#define THIN_FEATURE_COMPAT_SUPP	  0UL
#define THIN_FEATURE_COMPAT_RO_SUPP	  0UL
#define THIN_FEATURE_INCOMPAT_SUPP	  0UL

/*
 * Device creation/deletion.
 */
int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev);

/*
 * An internal snapshot.
 *
 * You can only snapshot a quiesced origin i.e. one that is either
 * suspended or not instanced at all.
 */
int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev,
			dm_thin_id origin);

/*
 * Deletes a virtual device from the metadata.  It _is_ safe to call this
 * when that device is open.  Operations on that device will just start
 * failing.  You still need to call close() on the device.
 */
int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
			       dm_thin_id dev);

/*
 * Commits _all_ metadata changes: device creation, deletion, mapping
 * updates.
 */
int dm_pool_commit_metadata(struct dm_pool_metadata *pmd);

/*
 * Set/get userspace transaction id.
 */
int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
					uint64_t current_id,
					uint64_t new_id);

int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
					uint64_t *result);

/*
 * Hold/get root for userspace transaction.
 */
int dm_pool_hold_metadata_root(struct dm_pool_metadata *pmd);

int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd,
				   dm_block_t *result);

/*
 * Actions on a single virtual device.
 */

/*
 * Opening the same device more than once will fail with -EBUSY.
 */
int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
			     struct dm_thin_device **td);

int dm_pool_close_thin_device(struct dm_thin_device *td);

dm_thin_id dm_thin_dev_id(struct dm_thin_device *td);

struct dm_thin_lookup_result {
	dm_block_t block;
	int shared;
};

/*
 * Returns:
 *   -EWOULDBLOCK iff @can_block is set and would block.
 *   -ENODATA iff that mapping is not present.
 *   0 success
 */
int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
		       int can_block, struct dm_thin_lookup_result *result);

/*
 * Obtain an unused block.
 */
int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result);

/*
 * Insert or remove block.
 */
int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
			 dm_block_t data_block);

int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);

/*
 * Queries.
 */
int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
				     dm_block_t *highest_mapped);

int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result);

int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd,
				 dm_block_t *result);

int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
					  dm_block_t *result);

int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
				  dm_block_t *result);

int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result);

int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);

/*
 * Returns -ENOSPC if the new size is too small and already allocated
 * blocks would be lost.
 */
int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);

/*----------------------------------------------------------------*/

#endif
Commit	Line	Data
991d9fa0 JT	1	/*
	2	* Copyright (C) 2010-2011 Red Hat, Inc.
	3	*
	4	* This file is released under the GPL.
	5	*/
	6
	7	#ifndef DM_THIN_METADATA_H
	8	#define DM_THIN_METADATA_H
	9
	10	#include "persistent-data/dm-block-manager.h"
	11
	12	#define THIN_METADATA_BLOCK_SIZE 4096
	13
	14	/----------------------------------------------------------------/
	15
	16	struct dm_pool_metadata;
	17	struct dm_thin_device;
	18
	19	/*
	20	* Device identifier
	21	*/
	22	typedef uint64_t dm_thin_id;
	23
	24	/*
	25	* Reopens or creates a new, empty metadata volume.
	26	*/
	27	struct dm_pool_metadata dm_pool_metadata_open(struct block_device bdev,
	28	sector_t data_block_size);
	29
	30	int dm_pool_metadata_close(struct dm_pool_metadata *pmd);
	31
	32	/*
	33	* Compat feature flags. Any incompat flags beyond the ones
	34	* specified below will prevent use of the thin metadata.
	35	*/
	36	#define THIN_FEATURE_COMPAT_SUPP 0UL
	37	#define THIN_FEATURE_COMPAT_RO_SUPP 0UL
	38	#define THIN_FEATURE_INCOMPAT_SUPP 0UL
	39
	40	/*
	41	* Device creation/deletion.
	42	*/
	43	int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev);
	44
	45	/*
	46	* An internal snapshot.
	47	*
	48	* You can only snapshot a quiesced origin i.e. one that is either
	49	* suspended or not instanced at all.
	50	*/
	51	int dm_pool_create_snap(struct dm_pool_metadata *pmd, dm_thin_id dev,
	52	dm_thin_id origin);
	53
	54	/*
	55	* Deletes a virtual device from the metadata. It _is_ safe to call this
	56	* when that device is open. Operations on that device will just start
	57	* failing. You still need to call close() on the device.
	58	*/
	59	int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
	60	dm_thin_id dev);
	61
	62	/*
	63	* Commits _all_ metadata changes: device creation, deletion, mapping
	64	* updates.
65	*/
66	int dm_pool_commit_metadata(struct dm_pool_metadata *pmd);
67
68	/*
69	* Set/get userspace transaction id.
70	*/
71	int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
72	uint64_t current_id,
73	uint64_t new_id);
74
75	int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
76	uint64_t *result);
77
78	/*
79	* Hold/get root for userspace transaction.
80	*/
81	int dm_pool_hold_metadata_root(struct dm_pool_metadata *pmd);
82
83	int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd,
84	dm_block_t *result);
85
86	/*
87	* Actions on a single virtual device.
88	*/
89
90	/*
91	* Opening the same device more than once will fail with -EBUSY.
92	*/
93	int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
94	struct dm_thin_device **td);
95
96	int dm_pool_close_thin_device(struct dm_thin_device *td);
97
98	dm_thin_id dm_thin_dev_id(struct dm_thin_device *td);
99
100	struct dm_thin_lookup_result {
101	dm_block_t block;
102	int shared;
103	};
104
105	/*
106	* Returns:
107	* -EWOULDBLOCK iff @can_block is set and would block.
108	* -ENODATA iff that mapping is not present.
109	* 0 success
110	*/
111	int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
112	int can_block, struct dm_thin_lookup_result *result);
113
114	/*
115	* Obtain an unused block.
116	*/
117	int dm_pool_alloc_data_block(struct dm_pool_metadata pmd, dm_block_t result);
118
119	/*
120	* Insert or remove block.
121	*/
122	int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
123	dm_block_t data_block);
124
125	int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);
126
127	/*
128	* Queries.
129	*/
130	int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
131	dm_block_t *highest_mapped);
132
133	int dm_thin_get_mapped_count(struct dm_thin_device td, dm_block_t result);
134
135	int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd,
136	dm_block_t *result);
137
138	int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
139	dm_block_t *result);
140
141	int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
142	dm_block_t *result);
143
144	int dm_pool_get_data_block_size(struct dm_pool_metadata pmd, sector_t result);
145
146	int dm_pool_get_data_dev_size(struct dm_pool_metadata pmd, dm_block_t result);
147
148	/*
149	* Returns -ENOSPC if the new size is too small and already allocated
150	* blocks would be lost.
151	*/
152	int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
153
154	/----------------------------------------------------------------/
155
156	#endif