[linux-2.6-block.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-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;

	*result = count > 1;

	return 0;
}

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)
{
	enum allocation_event ev;
	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);

	return sm_ll_dec(&smd->ll, b, &ev);
}

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,
	.register_threshold_callback = NULL
};

struct dm_space_map *dm_sm_disk_create(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);
}
EXPORT_SYMBOL_GPL(dm_sm_disk_create);

struct dm_space_map *dm_sm_disk_open(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);
}
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
3241b1d3 JT	7	#include "dm-space-map-common.h"
	8	#include "dm-space-map-disk.h"
	9	#include "dm-space-map.h"
	10	#include "dm-transaction-manager.h"
	11
	12	#include <linux/list.h>
	13	#include <linux/slab.h>
1944ce60	14	#include <linux/export.h>
3241b1d3 JT	15	#include <linux/device-mapper.h>
	16
	17	#define DM_MSG_PREFIX "space map disk"
	18
	19	/----------------------------------------------------------------/
	20
	21	/*
	22	* Space map interface.
	23	*/
	24	struct sm_disk {
	25	struct dm_space_map sm;
	26
	27	struct ll_disk ll;
	28	struct ll_disk old_ll;
	29
	30	dm_block_t begin;
	31	dm_block_t nr_allocated_this_transaction;
	32	};
	33
	34	static void sm_disk_destroy(struct dm_space_map *sm)
	35	{
	36	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	37
	38	kfree(smd);
	39	}
	40
	41	static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
	42	{
	43	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	44
	45	return sm_ll_extend(&smd->ll, extra_blocks);
	46	}
	47
	48	static int sm_disk_get_nr_blocks(struct dm_space_map sm, dm_block_t count)
	49	{
	50	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	51	*count = smd->old_ll.nr_blocks;
	52
	53	return 0;
	54	}
	55
	56	static int sm_disk_get_nr_free(struct dm_space_map sm, dm_block_t count)
	57	{
	58	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	59	*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
	60
	61	return 0;
	62	}
	63
	64	static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
	65	uint32_t *result)
	66	{
	67	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	68	return sm_ll_lookup(&smd->ll, b, result);
	69	}
	70
	71	static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
	72	int *result)
	73	{
	74	int r;
	75	uint32_t count;
	76
	77	r = sm_disk_get_count(sm, b, &count);
	78	if (r)
79	return r;
80
145b9006 MS	81	*result = count > 1;
	82
	83	return 0;
3241b1d3 JT	84	}
	85
	86	static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
	87	uint32_t count)
	88	{
	89	int r;
	90	uint32_t old_count;
	91	enum allocation_event ev;
	92	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	93
	94	r = sm_ll_insert(&smd->ll, b, count, &ev);
	95	if (!r) {
	96	switch (ev) {
	97	case SM_NONE:
	98	break;
	99
	100	case SM_ALLOC:
	101	/*
	102	* This _must_ be free in the prior transaction
	103	* otherwise we've lost atomicity.
	104	*/
	105	smd->nr_allocated_this_transaction++;
	106	break;
	107
	108	case SM_FREE:
	109	/*
	110	* It's only free if it's also free in the last
	111	* transaction.
	112	*/
	113	r = sm_ll_lookup(&smd->old_ll, b, &old_count);
	114	if (r)
	115	return r;
	116
	117	if (!old_count)
	118	smd->nr_allocated_this_transaction--;
	119	break;
	120	}
	121	}
	122
	123	return r;
	124	}
	125
	126	static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
	127	{
	128	int r;
	129	enum allocation_event ev;
	130	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	131
	132	r = sm_ll_inc(&smd->ll, b, &ev);
	133	if (!r && (ev == SM_ALLOC))
	134	/*
	135	* This _must_ be free in the prior transaction
	136	* otherwise we've lost atomicity.
	137	*/
	138	smd->nr_allocated_this_transaction++;
	139
	140	return r;
	141	}
	142
	143	static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
	144	{
3241b1d3 JT	145	enum allocation_event ev;
	146	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	147
40c57f47	148	return sm_ll_dec(&smd->ll, b, &ev);
3241b1d3 JT	149	}
	150
	151	static int sm_disk_new_block(struct dm_space_map sm, dm_block_t b)
	152	{
	153	int r;
	154	enum allocation_event ev;
	155	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	156
	157	/* FIXME: we should loop round a couple of times */
	158	r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
	159	if (r)
	160	return r;
	161
	162	smd->begin = *b + 1;
	163	r = sm_ll_inc(&smd->ll, *b, &ev);
	164	if (!r) {
	165	BUG_ON(ev != SM_ALLOC);
	166	smd->nr_allocated_this_transaction++;
	167	}
	168
	169	return r;
	170	}
	171
	172	static int sm_disk_commit(struct dm_space_map *sm)
	173	{
	174	int r;
	175	dm_block_t nr_free;
	176	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	177
	178	r = sm_disk_get_nr_free(sm, &nr_free);
	179	if (r)
	180	return r;
	181
	182	r = sm_ll_commit(&smd->ll);
	183	if (r)
	184	return r;
	185
	186	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
	187	smd->begin = 0;
	188	smd->nr_allocated_this_transaction = 0;
	189
	190	r = sm_disk_get_nr_free(sm, &nr_free);
	191	if (r)
	192	return r;
	193
	194	return 0;
	195	}
	196
	197	static int sm_disk_root_size(struct dm_space_map sm, size_t result)
	198	{
	199	*result = sizeof(struct disk_sm_root);
	200
	201	return 0;
	202	}
	203
	204	static int sm_disk_copy_root(struct dm_space_map sm, void where_le, size_t max)
	205	{
	206	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
	207	struct disk_sm_root root_le;
	208
	209	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
	210	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
	211	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
	212	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
213
214	if (max < sizeof(root_le))
215	return -ENOSPC;
216
217	memcpy(where_le, &root_le, sizeof(root_le));
218
219	return 0;
220	}
221
222	/----------------------------------------------------------------/
223
224	static struct dm_space_map ops = {
225	.destroy = sm_disk_destroy,
226	.extend = sm_disk_extend,
227	.get_nr_blocks = sm_disk_get_nr_blocks,
228	.get_nr_free = sm_disk_get_nr_free,
229	.get_count = sm_disk_get_count,
230	.count_is_more_than_one = sm_disk_count_is_more_than_one,
231	.set_count = sm_disk_set_count,
232	.inc_block = sm_disk_inc_block,
233	.dec_block = sm_disk_dec_block,
234	.new_block = sm_disk_new_block,
235	.commit = sm_disk_commit,
236	.root_size = sm_disk_root_size,
7c3d3f2a JT	237	.copy_root = sm_disk_copy_root,
7c3d3f2a JT	238	.register_threshold_callback = NULL
3241b1d3 JT	239	};
3241b1d3 JT	240
3caf6d73 JT	241	struct dm_space_map dm_sm_disk_create(struct dm_transaction_manager tm,
3caf6d73 JT	242	dm_block_t nr_blocks)
3241b1d3 JT	243	{
	244	int r;
	245	struct sm_disk *smd;
	246
	247	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
	248	if (!smd)
	249	return ERR_PTR(-ENOMEM);
	250
	251	smd->begin = 0;
	252	smd->nr_allocated_this_transaction = 0;
	253	memcpy(&smd->sm, &ops, sizeof(smd->sm));
	254
	255	r = sm_ll_new_disk(&smd->ll, tm);
	256	if (r)
	257	goto bad;
	258
	259	r = sm_ll_extend(&smd->ll, nr_blocks);
	260	if (r)
	261	goto bad;
	262
	263	r = sm_disk_commit(&smd->sm);
	264	if (r)
	265	goto bad;
	266
	267	return &smd->sm;
	268
	269	bad:
	270	kfree(smd);
	271	return ERR_PTR(r);
	272	}
3241b1d3 JT	273	EXPORT_SYMBOL_GPL(dm_sm_disk_create);
3241b1d3 JT	274
3caf6d73 JT	275	struct dm_space_map dm_sm_disk_open(struct dm_transaction_manager tm,
3caf6d73 JT	276	void *root_le, size_t len)
3241b1d3 JT	277	{
	278	int r;
	279	struct sm_disk *smd;
	280
	281	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
	282	if (!smd)
	283	return ERR_PTR(-ENOMEM);
	284
	285	smd->begin = 0;
	286	smd->nr_allocated_this_transaction = 0;
	287	memcpy(&smd->sm, &ops, sizeof(smd->sm));
	288
	289	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
	290	if (r)
	291	goto bad;
	292
	293	r = sm_disk_commit(&smd->sm);
	294	if (r)
	295	goto bad;
	296
	297	return &smd->sm;
	298
	299	bad:
	300	kfree(smd);
	301	return ERR_PTR(r);
	302	}
3241b1d3 JT	303	EXPORT_SYMBOL_GPL(dm_sm_disk_open);
	304
	305	/----------------------------------------------------------------/