[deliverable/linux.git] / drivers / md / persistent-data / dm-space-map-disk.c

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

#include "dm-space-map-checker.h"
#include "dm-space-map-common.h"
#include "dm-space-map-disk.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"

#include <linux/list.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/device-mapper.h>

#define DM_MSG_PREFIX "space map disk"

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

/*
 * Space map interface.
 */
struct sm_disk {
	struct dm_space_map sm;

	struct ll_disk ll;
	struct ll_disk old_ll;

	dm_block_t begin;
	dm_block_t nr_allocated_this_transaction;
};

static void sm_disk_destroy(struct dm_space_map *sm)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	kfree(smd);
}

static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	return sm_ll_extend(&smd->ll, extra_blocks);
}

static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	*count = smd->old_ll.nr_blocks;

	return 0;
}

static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;

	return 0;
}

static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
			     uint32_t *result)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	return sm_ll_lookup(&smd->ll, b, result);
}

static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
					  int *result)
{
	int r;
	uint32_t count;

	r = sm_disk_get_count(sm, b, &count);
	if (r)
		return r;

	return count > 1;
}

static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
			     uint32_t count)
{
	int r;
	uint32_t old_count;
	enum allocation_event ev;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	r = sm_ll_insert(&smd->ll, b, count, &ev);
	if (!r) {
		switch (ev) {
		case SM_NONE:
			break;

		case SM_ALLOC:
			/*
			 * This _must_ be free in the prior transaction
			 * otherwise we've lost atomicity.
			 */
			smd->nr_allocated_this_transaction++;
			break;

		case SM_FREE:
			/*
			 * It's only free if it's also free in the last
			 * transaction.
			 */
			r = sm_ll_lookup(&smd->old_ll, b, &old_count);
			if (r)
				return r;

			if (!old_count)
				smd->nr_allocated_this_transaction--;
			break;
		}
	}

	return r;
}

static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
{
	int r;
	enum allocation_event ev;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	r = sm_ll_inc(&smd->ll, b, &ev);
	if (!r && (ev == SM_ALLOC))
		/*
		 * This _must_ be free in the prior transaction
		 * otherwise we've lost atomicity.
		 */
		smd->nr_allocated_this_transaction++;

	return r;
}

static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
{
	int r;
	uint32_t old_count;
	enum allocation_event ev;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	r = sm_ll_dec(&smd->ll, b, &ev);
	if (!r && (ev == SM_FREE)) {
		/*
		 * It's only free if it's also free in the last
		 * transaction.
		 */
		r = sm_ll_lookup(&smd->old_ll, b, &old_count);
		if (r)
			return r;

		if (!old_count)
			smd->nr_allocated_this_transaction--;
	}

	return r;
}

static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
{
	int r;
	enum allocation_event ev;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	/* FIXME: we should loop round a couple of times */
	r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
	if (r)
		return r;

	smd->begin = *b + 1;
	r = sm_ll_inc(&smd->ll, *b, &ev);
	if (!r) {
		BUG_ON(ev != SM_ALLOC);
		smd->nr_allocated_this_transaction++;
	}

	return r;
}

static int sm_disk_commit(struct dm_space_map *sm)
{
	int r;
	dm_block_t nr_free;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	r = sm_disk_get_nr_free(sm, &nr_free);
	if (r)
		return r;

	r = sm_ll_commit(&smd->ll);
	if (r)
		return r;

	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
	smd->begin = 0;
	smd->nr_allocated_this_transaction = 0;

	r = sm_disk_get_nr_free(sm, &nr_free);
	if (r)
		return r;

	return 0;
}

static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
{
	*result = sizeof(struct disk_sm_root);

	return 0;
}

static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
{
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	struct disk_sm_root root_le;

	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);

	if (max < sizeof(root_le))
		return -ENOSPC;

	memcpy(where_le, &root_le, sizeof(root_le));

	return 0;
}

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

static struct dm_space_map ops = {
	.destroy = sm_disk_destroy,
	.extend = sm_disk_extend,
	.get_nr_blocks = sm_disk_get_nr_blocks,
	.get_nr_free = sm_disk_get_nr_free,
	.get_count = sm_disk_get_count,
	.count_is_more_than_one = sm_disk_count_is_more_than_one,
	.set_count = sm_disk_set_count,
	.inc_block = sm_disk_inc_block,
	.dec_block = sm_disk_dec_block,
	.new_block = sm_disk_new_block,
	.commit = sm_disk_commit,
	.root_size = sm_disk_root_size,
	.copy_root = sm_disk_copy_root
};

static struct dm_space_map *dm_sm_disk_create_real(
	struct dm_transaction_manager *tm,
	dm_block_t nr_blocks)
{
	int r;
	struct sm_disk *smd;

	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
	if (!smd)
		return ERR_PTR(-ENOMEM);

	smd->begin = 0;
	smd->nr_allocated_this_transaction = 0;
	memcpy(&smd->sm, &ops, sizeof(smd->sm));

	r = sm_ll_new_disk(&smd->ll, tm);
	if (r)
		goto bad;

	r = sm_ll_extend(&smd->ll, nr_blocks);
	if (r)
		goto bad;

	r = sm_disk_commit(&smd->sm);
	if (r)
		goto bad;

	return &smd->sm;

bad:
	kfree(smd);
	return ERR_PTR(r);
}

struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
				       dm_block_t nr_blocks)
{
	struct dm_space_map *sm = dm_sm_disk_create_real(tm, nr_blocks);
	struct dm_space_map *smc;

	if (IS_ERR_OR_NULL(sm))
		return sm;

	smc = dm_sm_checker_create_fresh(sm);
	if (IS_ERR(smc))
		dm_sm_destroy(sm);

	return smc;
}
EXPORT_SYMBOL_GPL(dm_sm_disk_create);

static struct dm_space_map *dm_sm_disk_open_real(
	struct dm_transaction_manager *tm,
	void *root_le, size_t len)
{
	int r;
	struct sm_disk *smd;

	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
	if (!smd)
		return ERR_PTR(-ENOMEM);

	smd->begin = 0;
	smd->nr_allocated_this_transaction = 0;
	memcpy(&smd->sm, &ops, sizeof(smd->sm));

	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
	if (r)
		goto bad;

	r = sm_disk_commit(&smd->sm);
	if (r)
		goto bad;

	return &smd->sm;

bad:
	kfree(smd);
	return ERR_PTR(r);
}

struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
				     void *root_le, size_t len)
{
	return dm_sm_checker_create(
		dm_sm_disk_open_real(tm, root_le, len));
}
EXPORT_SYMBOL_GPL(dm_sm_disk_open);

/*----------------------------------------------------------------*/
Commit	Line	Data
3241b1d3 JT	1	/*
	2	* Copyright (C) 2011 Red Hat, Inc.
	3	*
	4	* This file is released under the GPL.
	5	*/
	6
	7	#include "dm-space-map-checker.h"
	8	#include "dm-space-map-common.h"
	9	#include "dm-space-map-disk.h"
	10	#include "dm-space-map.h"
	11	#include "dm-transaction-manager.h"
	12
	13	#include <linux/list.h>
	14	#include <linux/slab.h>
1944ce60	15	#include <linux/export.h>
3241b1d3 JT	16	#include <linux/device-mapper.h>
	17
	18	#define DM_MSG_PREFIX "space map disk"
	19
	20	/----------------------------------------------------------------/
	21
	22	/*
	23	* Space map interface.
	24	*/
	25	struct sm_disk {
	26	struct dm_space_map sm;
	27
	28	struct ll_disk ll;
	29	struct ll_disk old_ll;
	30
	31	dm_block_t begin;
	32	dm_block_t nr_allocated_this_transaction;
	33	};
	34
	35	static void sm_disk_destroy(struct dm_space_map *sm)
	36	{
	37	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	38
	39	kfree(smd);
	40	}
	41
	42	static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
	43	{
	44	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	45
	46	return sm_ll_extend(&smd->ll, extra_blocks);
	47	}
	48
	49	static int sm_disk_get_nr_blocks(struct dm_space_map sm, dm_block_t count)
	50	{
	51	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	52	*count = smd->old_ll.nr_blocks;
	53
	54	return 0;
	55	}
	56
	57	static int sm_disk_get_nr_free(struct dm_space_map sm, dm_block_t count)
	58	{
	59	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	60	*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
	61
	62	return 0;
	63	}
	64
	65	static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
	66	uint32_t *result)
	67	{
	68	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	69	return sm_ll_lookup(&smd->ll, b, result);
	70	}
	71
	72	static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
	73	int *result)
	74	{
	75	int r;
	76	uint32_t count;
	77
	78	r = sm_disk_get_count(sm, b, &count);
	79	if (r)
80	return r;
81
82	return count > 1;
83	}
84
85	static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
86	uint32_t count)
87	{
88	int r;
89	uint32_t old_count;
90	enum allocation_event ev;
91	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
92
93	r = sm_ll_insert(&smd->ll, b, count, &ev);
94	if (!r) {
95	switch (ev) {
96	case SM_NONE:
97	break;
98
99	case SM_ALLOC:
100	/*
101	* This _must_ be free in the prior transaction
102	* otherwise we've lost atomicity.
103	*/
104	smd->nr_allocated_this_transaction++;
105	break;
106
107	case SM_FREE:
108	/*
109	* It's only free if it's also free in the last
110	* transaction.
111	*/
112	r = sm_ll_lookup(&smd->old_ll, b, &old_count);
113	if (r)
114	return r;
115
116	if (!old_count)
117	smd->nr_allocated_this_transaction--;
118	break;
119	}
120	}
121
122	return r;
123	}
124
125	static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
126	{
127	int r;
128	enum allocation_event ev;
129	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
130
131	r = sm_ll_inc(&smd->ll, b, &ev);
132	if (!r && (ev == SM_ALLOC))
133	/*
134	* This _must_ be free in the prior transaction
135	* otherwise we've lost atomicity.
136	*/
137	smd->nr_allocated_this_transaction++;
138
139	return r;
140	}
141
142	static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
143	{
144	int r;
145	uint32_t old_count;
146	enum allocation_event ev;
147	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
148
149	r = sm_ll_dec(&smd->ll, b, &ev);
150	if (!r && (ev == SM_FREE)) {
151	/*
152	* It's only free if it's also free in the last
153	* transaction.
154	*/
155	r = sm_ll_lookup(&smd->old_ll, b, &old_count);
156	if (r)
157	return r;
158
159	if (!old_count)
160	smd->nr_allocated_this_transaction--;
161	}
162
163	return r;
164	}
165
166	static int sm_disk_new_block(struct dm_space_map sm, dm_block_t b)
167	{
168	int r;
169	enum allocation_event ev;
170	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
171
172	/* FIXME: we should loop round a couple of times */
173	r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
174	if (r)
175	return r;
176
177	smd->begin = *b + 1;
178	r = sm_ll_inc(&smd->ll, *b, &ev);
179	if (!r) {
180	BUG_ON(ev != SM_ALLOC);
181	smd->nr_allocated_this_transaction++;
182	}
183
184	return r;
185	}
186
187	static int sm_disk_commit(struct dm_space_map *sm)
188	{
189	int r;
190	dm_block_t nr_free;
191	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
192
193	r = sm_disk_get_nr_free(sm, &nr_free);
194	if (r)
195	return r;
196
197	r = sm_ll_commit(&smd->ll);
198	if (r)
199	return r;
200
201	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
202	smd->begin = 0;
203	smd->nr_allocated_this_transaction = 0;
204
205	r = sm_disk_get_nr_free(sm, &nr_free);
206	if (r)
207	return r;
208
209	return 0;
210	}
211
212	static int sm_disk_root_size(struct dm_space_map sm, size_t result)
213	{
214	*result = sizeof(struct disk_sm_root);
215
216	return 0;
217	}
218
219	static int sm_disk_copy_root(struct dm_space_map sm, void where_le, size_t max)
220	{
221	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
222	struct disk_sm_root root_le;
223
224	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
225	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
226	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
227	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
228
229	if (max < sizeof(root_le))
230	return -ENOSPC;
231
232	memcpy(where_le, &root_le, sizeof(root_le));
233
234	return 0;
235	}
236
237	/----------------------------------------------------------------/
238
239	static struct dm_space_map ops = {
240	.destroy = sm_disk_destroy,
241	.extend = sm_disk_extend,
242	.get_nr_blocks = sm_disk_get_nr_blocks,
243	.get_nr_free = sm_disk_get_nr_free,
244	.get_count = sm_disk_get_count,
245	.count_is_more_than_one = sm_disk_count_is_more_than_one,
246	.set_count = sm_disk_set_count,
247	.inc_block = sm_disk_inc_block,
248	.dec_block = sm_disk_dec_block,
249	.new_block = sm_disk_new_block,
250	.commit = sm_disk_commit,
251	.root_size = sm_disk_root_size,
252	.copy_root = sm_disk_copy_root
253	};
254
255	static struct dm_space_map *dm_sm_disk_create_real(
256	struct dm_transaction_manager *tm,
257	dm_block_t nr_blocks)
258	{
259	int r;
260	struct sm_disk *smd;
261
262	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
263	if (!smd)
264	return ERR_PTR(-ENOMEM);
265
266	smd->begin = 0;
267	smd->nr_allocated_this_transaction = 0;
268	memcpy(&smd->sm, &ops, sizeof(smd->sm));
269
270	r = sm_ll_new_disk(&smd->ll, tm);
271	if (r)
272	goto bad;
273
274	r = sm_ll_extend(&smd->ll, nr_blocks);
275	if (r)
276	goto bad;
277
278	r = sm_disk_commit(&smd->sm);
279	if (r)
280	goto bad;
281
282	return &smd->sm;
283
284	bad:
285	kfree(smd);
286	return ERR_PTR(r);
287	}
288
289	struct dm_space_map dm_sm_disk_create(struct dm_transaction_manager tm,
290	dm_block_t nr_blocks)
291	{
292	struct dm_space_map *sm = dm_sm_disk_create_real(tm, nr_blocks);
62662303 MS	293	struct dm_space_map *smc;
	294
	295	if (IS_ERR_OR_NULL(sm))
	296	return sm;
	297
	298	smc = dm_sm_checker_create_fresh(sm);
	299	if (IS_ERR(smc))
	300	dm_sm_destroy(sm);
	301
	302	return smc;
3241b1d3 JT	303	}
	304	EXPORT_SYMBOL_GPL(dm_sm_disk_create);
	305
	306	static struct dm_space_map *dm_sm_disk_open_real(
	307	struct dm_transaction_manager *tm,
	308	void *root_le, size_t len)
	309	{
	310	int r;
	311	struct sm_disk *smd;
	312
	313	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
	314	if (!smd)
	315	return ERR_PTR(-ENOMEM);
	316
	317	smd->begin = 0;
	318	smd->nr_allocated_this_transaction = 0;
	319	memcpy(&smd->sm, &ops, sizeof(smd->sm));
	320
	321	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
	322	if (r)
	323	goto bad;
	324
	325	r = sm_disk_commit(&smd->sm);
	326	if (r)
	327	goto bad;
	328
	329	return &smd->sm;
	330
	331	bad:
	332	kfree(smd);
	333	return ERR_PTR(r);
	334	}
	335
	336	struct dm_space_map dm_sm_disk_open(struct dm_transaction_manager tm,
	337	void *root_le, size_t len)
	338	{
	339	return dm_sm_checker_create(
	340	dm_sm_disk_open_real(tm, root_le, len));
	341	}
	342	EXPORT_SYMBOL_GPL(dm_sm_disk_open);
	343
	344	/----------------------------------------------------------------/