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Commit 44feb387 authored by Mike Snitzer's avatar Mike Snitzer Committed by Alasdair G Kergon
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dm thin: prepare to separate bio_prison code 



The bio prison code will be useful to share with future DM targets.

Prepare to move this code into a separate module, adding a dm prefix
to structures and functions that will be exported.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 28eed34e

drivers/md/dm-thin.c

+131 −90
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ 
 * i) plug io further to this physical block. (see bio_prison code).

 *

 * ii) quiesce any read io to that shared data block.  Obviously

 * including all devices that share this block.  (see deferred_set code)

 * including all devices that share this block.  (see dm_deferred_set code)

 *

 * iii) copy the data block to a newly allocate block.  This step can be

 * missed out if the io covers the block. (schedule_copy).
@@ -104,9 +104,9 @@ 
 * by a key, multiple bios can be in the same cell.  When the cell is

 * subsequently unlocked the bios become available.

 */

struct bio_prison;

struct dm_bio_prison;



struct cell_key {

struct dm_cell_key {

	int virtual;

	dm_thin_id dev;

	dm_block_t block;
@@ -114,13 +114,13 @@ struct cell_key { 


struct dm_bio_prison_cell {

	struct hlist_node list;

	struct bio_prison *prison;

	struct cell_key key;

	struct dm_bio_prison *prison;

	struct dm_cell_key key;

	struct bio *holder;

	struct bio_list bios;

};



struct bio_prison {

struct dm_bio_prison {

	spinlock_t lock;

	mempool_t *cell_pool;
@@ -148,13 +148,13 @@ static struct kmem_cache *_cell_cache; 
 * @nr_cells should be the number of cells you want in use _concurrently_.

 * Don't confuse it with the number of distinct keys.

 */

static struct bio_prison *prison_create(unsigned nr_cells)

static struct dm_bio_prison *dm_bio_prison_create(unsigned nr_cells)

{

	unsigned i;

	uint32_t nr_buckets = calc_nr_buckets(nr_cells);

	size_t len = sizeof(struct bio_prison) +

	size_t len = sizeof(struct dm_bio_prison) +

		(sizeof(struct hlist_head) * nr_buckets);

	struct bio_prison *prison = kmalloc(len, GFP_KERNEL);

	struct dm_bio_prison *prison = kmalloc(len, GFP_KERNEL);



	if (!prison)

		return NULL;
@@ -175,13 +175,13 @@ static struct bio_prison *prison_create(unsigned nr_cells) 
	return prison;

}



static void prison_destroy(struct bio_prison *prison)

static void dm_bio_prison_destroy(struct dm_bio_prison *prison)

{

	mempool_destroy(prison->cell_pool);

	kfree(prison);

}



static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key)

static uint32_t hash_key(struct dm_bio_prison *prison, struct dm_cell_key *key)

{

	const unsigned long BIG_PRIME = 4294967291UL;

	uint64_t hash = key->block * BIG_PRIME;
@@ -189,7 +189,7 @@ static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key) 
	return (uint32_t) (hash & prison->hash_mask);

}



static int keys_equal(struct cell_key *lhs, struct cell_key *rhs)

static int keys_equal(struct dm_cell_key *lhs, struct dm_cell_key *rhs)

{

	       return (lhs->virtual == rhs->virtual) &&

		       (lhs->dev == rhs->dev) &&
@@ -197,7 +197,7 @@ static int keys_equal(struct cell_key *lhs, struct cell_key *rhs) 
}



static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket,

						  struct cell_key *key)

						  struct dm_cell_key *key)

{

	struct dm_bio_prison_cell *cell;

	struct hlist_node *tmp;
@@ -215,7 +215,7 @@ static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket, 
 *

 * Returns 1 if the cell was already held, 0 if @inmate is the new holder.

 */

static int bio_detain(struct bio_prison *prison, struct cell_key *key,

static int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,

			 struct bio *inmate, struct dm_bio_prison_cell **ref)

{

	int r = 1;
@@ -277,7 +277,7 @@ out: 
 */

static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inmates)

{

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;



	hlist_del(&cell->list);
@@ -289,10 +289,10 @@ static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inm 
	mempool_free(cell, prison->cell_pool);

}



static void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)

static void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)

{

	unsigned long flags;

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;



	spin_lock_irqsave(&prison->lock, flags);

	__cell_release(cell, bios);
@@ -313,10 +313,10 @@ static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio 
	__cell_release(cell, NULL);

}



static void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)

static void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)

{

	unsigned long flags;

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;



	spin_lock_irqsave(&prison->lock, flags);

	__cell_release_singleton(cell, bio);
@@ -329,7 +329,7 @@ static void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio * 
static void __cell_release_no_holder(struct dm_bio_prison_cell *cell,

				     struct bio_list *inmates)

{

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;



	hlist_del(&cell->list);

	bio_list_merge(inmates, &cell->bios);
@@ -337,20 +337,20 @@ static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, 
	mempool_free(cell, prison->cell_pool);

}



static void cell_release_no_holder(struct dm_bio_prison_cell *cell,

static void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell,

				      struct bio_list *inmates)

{

	unsigned long flags;

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;



	spin_lock_irqsave(&prison->lock, flags);

	__cell_release_no_holder(cell, inmates);

	spin_unlock_irqrestore(&prison->lock, flags);

}



static void cell_error(struct dm_bio_prison_cell *cell)

static void dm_cell_error(struct dm_bio_prison_cell *cell)

{

	struct bio_prison *prison = cell->prison;

	struct dm_bio_prison *prison = cell->prison;

	struct bio_list bios;

	struct bio *bio;

	unsigned long flags;
@@ -374,23 +374,28 @@ static void cell_error(struct dm_bio_prison_cell *cell) 
 * new mapping could free the old block that the read bios are mapped to.

 */



struct deferred_set;

struct deferred_entry {

	struct deferred_set *ds;

struct dm_deferred_set;

struct dm_deferred_entry {

	struct dm_deferred_set *ds;

	unsigned count;

	struct list_head work_items;

};



struct deferred_set {

struct dm_deferred_set {

	spinlock_t lock;

	unsigned current_entry;

	unsigned sweeper;

	struct deferred_entry entries[DEFERRED_SET_SIZE];

	struct dm_deferred_entry entries[DEFERRED_SET_SIZE];

};



static void ds_init(struct deferred_set *ds)

static struct dm_deferred_set *dm_deferred_set_create(void)

{

	int i;

	struct dm_deferred_set *ds;



	ds = kmalloc(sizeof(*ds), GFP_KERNEL);

	if (!ds)

		return NULL;



	spin_lock_init(&ds->lock);

	ds->current_entry = 0;
@@ -400,12 +405,19 @@ static void ds_init(struct deferred_set *ds) 
		ds->entries[i].count = 0;

		INIT_LIST_HEAD(&ds->entries[i].work_items);

	}



	return ds;

}



static struct deferred_entry *ds_inc(struct deferred_set *ds)

static void dm_deferred_set_destroy(struct dm_deferred_set *ds)

{

	kfree(ds);

}



static struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds)

{

	unsigned long flags;

	struct deferred_entry *entry;

	struct dm_deferred_entry *entry;



	spin_lock_irqsave(&ds->lock, flags);

	entry = ds->entries + ds->current_entry;
@@ -420,7 +432,7 @@ static unsigned ds_next(unsigned index) 
	return (index + 1) % DEFERRED_SET_SIZE;

}



static void __sweep(struct deferred_set *ds, struct list_head *head)

static void __sweep(struct dm_deferred_set *ds, struct list_head *head)

{

	while ((ds->sweeper != ds->current_entry) &&

	       !ds->entries[ds->sweeper].count) {
@@ -432,7 +444,7 @@ static void __sweep(struct deferred_set *ds, struct list_head *head) 
		list_splice_init(&ds->entries[ds->sweeper].work_items, head);

}



static void ds_dec(struct deferred_entry *entry, struct list_head *head)

static void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head)

{

	unsigned long flags;
@@ -446,7 +458,7 @@ static void ds_dec(struct deferred_entry *entry, struct list_head *head) 
/*

 * Returns 1 if deferred or 0 if no pending items to delay job.

 */

static int ds_add_work(struct deferred_set *ds, struct list_head *work)

static int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work)

{

	int r = 1;

	unsigned long flags;
@@ -467,13 +479,28 @@ static int ds_add_work(struct deferred_set *ds, struct list_head *work) 
	return r;

}



static int __init dm_bio_prison_init(void)

{

	_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);

	if (!_cell_cache)

		return -ENOMEM;



	return 0;

}



static void __exit dm_bio_prison_exit(void)

{

	kmem_cache_destroy(_cell_cache);

	_cell_cache = NULL;

}



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



/*

 * Key building.

 */

static void build_data_key(struct dm_thin_device *td,

			   dm_block_t b, struct cell_key *key)

			   dm_block_t b, struct dm_cell_key *key)

{

	key->virtual = 0;

	key->dev = dm_thin_dev_id(td);
@@ -481,7 +508,7 @@ static void build_data_key(struct dm_thin_device *td, 
}



static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,

			      struct cell_key *key)

			      struct dm_cell_key *key)

{

	key->virtual = 1;

	key->dev = dm_thin_dev_id(td);
@@ -534,7 +561,7 @@ struct pool { 
	unsigned low_water_triggered:1;	/* A dm event has been sent */

	unsigned no_free_space:1;	/* A -ENOSPC warning has been issued */



	struct bio_prison *prison;

	struct dm_bio_prison *prison;

	struct dm_kcopyd_client *copier;



	struct workqueue_struct *wq;
@@ -552,8 +579,8 @@ struct pool { 


	struct bio_list retry_on_resume_list;



	struct deferred_set shared_read_ds;

	struct deferred_set all_io_ds;

	struct dm_deferred_set *shared_read_ds;

	struct dm_deferred_set *all_io_ds;



	struct dm_thin_new_mapping *next_mapping;

	mempool_t *mapping_pool;
@@ -660,8 +687,8 @@ static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev 


struct dm_thin_endio_hook {

	struct thin_c *tc;

	struct deferred_entry *shared_read_entry;

	struct deferred_entry *all_io_entry;

	struct dm_deferred_entry *shared_read_entry;

	struct dm_deferred_entry *all_io_entry;

	struct dm_thin_new_mapping *overwrite_mapping;

};
@@ -877,7 +904,7 @@ static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell, 
	unsigned long flags;



	spin_lock_irqsave(&pool->lock, flags);

	cell_release(cell, &pool->deferred_bios);

	dm_cell_release(cell, &pool->deferred_bios);

	spin_unlock_irqrestore(&tc->pool->lock, flags);



	wake_worker(pool);
@@ -896,7 +923,7 @@ static void cell_defer_except(struct thin_c *tc, struct dm_bio_prison_cell *cell 
	bio_list_init(&bios);



	spin_lock_irqsave(&pool->lock, flags);

	cell_release_no_holder(cell, &pool->deferred_bios);

	dm_cell_release_no_holder(cell, &pool->deferred_bios);

	spin_unlock_irqrestore(&pool->lock, flags);



	wake_worker(pool);
@@ -906,7 +933,7 @@ static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m) 
{

	if (m->bio)

		m->bio->bi_end_io = m->saved_bi_end_io;

	cell_error(m->cell);

	dm_cell_error(m->cell);

	list_del(&m->list);

	mempool_free(m, m->tc->pool->mapping_pool);

}
@@ -921,7 +948,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m) 
		bio->bi_end_io = m->saved_bi_end_io;



	if (m->err) {

		cell_error(m->cell);

		dm_cell_error(m->cell);

		goto out;

	}
@@ -933,7 +960,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m) 
	r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);

	if (r) {

		DMERR("dm_thin_insert_block() failed");

		cell_error(m->cell);

		dm_cell_error(m->cell);

		goto out;

	}
@@ -1067,7 +1094,7 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, 
	m->err = 0;

	m->bio = NULL;



	if (!ds_add_work(&pool->shared_read_ds, &m->list))

	if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))

		m->quiesced = 1;



	/*
@@ -1099,7 +1126,7 @@ static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, 
		if (r < 0) {

			mempool_free(m, pool->mapping_pool);

			DMERR("dm_kcopyd_copy() failed");

			cell_error(cell);

			dm_cell_error(cell);

		}

	}

}
@@ -1164,7 +1191,7 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block, 
		if (r < 0) {

			mempool_free(m, pool->mapping_pool);

			DMERR("dm_kcopyd_zero() failed");

			cell_error(cell);

			dm_cell_error(cell);

		}

	}

}
@@ -1276,7 +1303,7 @@ static void no_space(struct dm_bio_prison_cell *cell) 
	struct bio_list bios;



	bio_list_init(&bios);

	cell_release(cell, &bios);

	dm_cell_release(cell, &bios);



	while ((bio = bio_list_pop(&bios)))

		retry_on_resume(bio);
@@ -1288,13 +1315,13 @@ static void process_discard(struct thin_c *tc, struct bio *bio) 
	unsigned long flags;

	struct pool *pool = tc->pool;

	struct dm_bio_prison_cell *cell, *cell2;

	struct cell_key key, key2;

	struct dm_cell_key key, key2;

	dm_block_t block = get_bio_block(tc, bio);

	struct dm_thin_lookup_result lookup_result;

	struct dm_thin_new_mapping *m;



	build_virtual_key(tc->td, block, &key);

	if (bio_detain(tc->pool->prison, &key, bio, &cell))

	if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))

		return;



	r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
@@ -1306,8 +1333,8 @@ static void process_discard(struct thin_c *tc, struct bio *bio) 
		 * on this block.

		 */

		build_data_key(tc->td, lookup_result.block, &key2);

		if (bio_detain(tc->pool->prison, &key2, bio, &cell2)) {

			cell_release_singleton(cell, bio);

		if (dm_bio_detain(tc->pool->prison, &key2, bio, &cell2)) {

			dm_cell_release_singleton(cell, bio);

			break;

		}
@@ -1326,7 +1353,7 @@ static void process_discard(struct thin_c *tc, struct bio *bio) 
			m->err = 0;

			m->bio = bio;



			if (!ds_add_work(&pool->all_io_ds, &m->list)) {

			if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {

				spin_lock_irqsave(&pool->lock, flags);

				list_add(&m->list, &pool->prepared_discards);

				spin_unlock_irqrestore(&pool->lock, flags);
@@ -1338,8 +1365,8 @@ static void process_discard(struct thin_c *tc, struct bio *bio) 
			 * a block boundary.  So we submit the discard of a

			 * partial block appropriately.

			 */

			cell_release_singleton(cell, bio);

			cell_release_singleton(cell2, bio);

			dm_cell_release_singleton(cell, bio);

			dm_cell_release_singleton(cell2, bio);

			if ((!lookup_result.shared) && pool->pf.discard_passdown)

				remap_and_issue(tc, bio, lookup_result.block);

			else
@@ -1351,20 +1378,20 @@ static void process_discard(struct thin_c *tc, struct bio *bio) 
		/*

		 * It isn't provisioned, just forget it.

		 */

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		bio_endio(bio, 0);

		break;



	default:

		DMERR("discard: find block unexpectedly returned %d", r);

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		bio_io_error(bio);

		break;

	}

}



static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,

			  struct cell_key *key,

			  struct dm_cell_key *key,

			  struct dm_thin_lookup_result *lookup_result,

			  struct dm_bio_prison_cell *cell)

{
@@ -1384,7 +1411,7 @@ static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block, 


	default:

		DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);

		cell_error(cell);

		dm_cell_error(cell);

		break;

	}

}
@@ -1395,14 +1422,14 @@ static void process_shared_bio(struct thin_c *tc, struct bio *bio, 
{

	struct dm_bio_prison_cell *cell;

	struct pool *pool = tc->pool;

	struct cell_key key;

	struct dm_cell_key key;



	/*

	 * If cell is already occupied, then sharing is already in the process

	 * of being broken so we have nothing further to do here.

	 */

	build_data_key(tc->td, lookup_result->block, &key);

	if (bio_detain(pool->prison, &key, bio, &cell))

	if (dm_bio_detain(pool->prison, &key, bio, &cell))

		return;



	if (bio_data_dir(bio) == WRITE && bio->bi_size)
@@ -1410,9 +1437,9 @@ static void process_shared_bio(struct thin_c *tc, struct bio *bio, 
	else {

		struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;



		h->shared_read_entry = ds_inc(&pool->shared_read_ds);

		h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);



		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		remap_and_issue(tc, bio, lookup_result->block);

	}

}
@@ -1427,7 +1454,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block 
	 * Remap empty bios (flushes) immediately, without provisioning.

	 */

	if (!bio->bi_size) {

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		remap_and_issue(tc, bio, 0);

		return;

	}
@@ -1437,7 +1464,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block 
	 */

	if (bio_data_dir(bio) == READ) {

		zero_fill_bio(bio);

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		bio_endio(bio, 0);

		return;

	}
@@ -1458,7 +1485,7 @@ static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block 
	default:

		DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);

		set_pool_mode(tc->pool, PM_READ_ONLY);

		cell_error(cell);

		dm_cell_error(cell);

		break;

	}

}
@@ -1468,7 +1495,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio) 
	int r;

	dm_block_t block = get_bio_block(tc, bio);

	struct dm_bio_prison_cell *cell;

	struct cell_key key;

	struct dm_cell_key key;

	struct dm_thin_lookup_result lookup_result;



	/*
@@ -1476,7 +1503,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio) 
	 * being provisioned so we have nothing further to do here.

	 */

	build_virtual_key(tc->td, block, &key);

	if (bio_detain(tc->pool->prison, &key, bio, &cell))

	if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))

		return;



	r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
@@ -1491,7 +1518,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio) 
		 * TODO: this will probably have to change when discard goes

		 * back in.

		 */

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);



		if (lookup_result.shared)

			process_shared_bio(tc, bio, block, &lookup_result);
@@ -1501,7 +1528,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio) 


	case -ENODATA:

		if (bio_data_dir(bio) == READ && tc->origin_dev) {

			cell_release_singleton(cell, bio);

			dm_cell_release_singleton(cell, bio);

			remap_to_origin_and_issue(tc, bio);

		} else

			provision_block(tc, bio, block, cell);
@@ -1509,7 +1536,7 @@ static void process_bio(struct thin_c *tc, struct bio *bio) 


	default:

		DMERR("dm_thin_find_block() failed, error = %d", r);

		cell_release_singleton(cell, bio);

		dm_cell_release_singleton(cell, bio);

		bio_io_error(bio);

		break;

	}
@@ -1718,7 +1745,7 @@ static struct dm_thin_endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *b 


	h->tc = tc;

	h->shared_read_entry = NULL;

	h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds);

	h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : dm_deferred_entry_inc(pool->all_io_ds);

	h->overwrite_mapping = NULL;



	return h;
@@ -1928,7 +1955,7 @@ static void __pool_destroy(struct pool *pool) 
	if (dm_pool_metadata_close(pool->pmd) < 0)

		DMWARN("%s: dm_pool_metadata_close() failed.", __func__);



	prison_destroy(pool->prison);

	dm_bio_prison_destroy(pool->prison);

	dm_kcopyd_client_destroy(pool->copier);



	if (pool->wq)
@@ -1938,6 +1965,8 @@ static void __pool_destroy(struct pool *pool) 
		mempool_free(pool->next_mapping, pool->mapping_pool);

	mempool_destroy(pool->mapping_pool);

	mempool_destroy(pool->endio_hook_pool);

	dm_deferred_set_destroy(pool->shared_read_ds);

	dm_deferred_set_destroy(pool->all_io_ds);

	kfree(pool);

}
@@ -1976,7 +2005,7 @@ static struct pool *pool_create(struct mapped_device *pool_md, 
		pool->sectors_per_block_shift = __ffs(block_size);

	pool->low_water_blocks = 0;

	pool_features_init(&pool->pf);

	pool->prison = prison_create(PRISON_CELLS);

	pool->prison = dm_bio_prison_create(PRISON_CELLS);

	if (!pool->prison) {

		*error = "Error creating pool's bio prison";

		err_p = ERR_PTR(-ENOMEM);
@@ -2012,8 +2041,20 @@ static struct pool *pool_create(struct mapped_device *pool_md, 
	pool->low_water_triggered = 0;

	pool->no_free_space = 0;

	bio_list_init(&pool->retry_on_resume_list);

	ds_init(&pool->shared_read_ds);

	ds_init(&pool->all_io_ds);



	pool->shared_read_ds = dm_deferred_set_create();

	if (!pool->shared_read_ds) {

		*error = "Error creating pool's shared read deferred set";

		err_p = ERR_PTR(-ENOMEM);

		goto bad_shared_read_ds;

	}



	pool->all_io_ds = dm_deferred_set_create();

	if (!pool->all_io_ds) {

		*error = "Error creating pool's all io deferred set";

		err_p = ERR_PTR(-ENOMEM);

		goto bad_all_io_ds;

	}



	pool->next_mapping = NULL;

	pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
@@ -2042,11 +2083,15 @@ static struct pool *pool_create(struct mapped_device *pool_md, 
bad_endio_hook_pool:

	mempool_destroy(pool->mapping_pool);

bad_mapping_pool:

	dm_deferred_set_destroy(pool->all_io_ds);

bad_all_io_ds:

	dm_deferred_set_destroy(pool->shared_read_ds);

bad_shared_read_ds:

	destroy_workqueue(pool->wq);

bad_wq:

	dm_kcopyd_client_destroy(pool->copier);

bad_kcopyd_client:

	prison_destroy(pool->prison);

	dm_bio_prison_destroy(pool->prison);

bad_prison:

	kfree(pool);

bad_pool:
@@ -2982,7 +3027,7 @@ static int thin_endio(struct dm_target *ti, 


	if (h->shared_read_entry) {

		INIT_LIST_HEAD(&work);

		ds_dec(h->shared_read_entry, &work);

		dm_deferred_entry_dec(h->shared_read_entry, &work);



		spin_lock_irqsave(&pool->lock, flags);

		list_for_each_entry_safe(m, tmp, &work, list) {
@@ -2995,7 +3040,7 @@ static int thin_endio(struct dm_target *ti, 


	if (h->all_io_entry) {

		INIT_LIST_HEAD(&work);

		ds_dec(h->all_io_entry, &work);

		dm_deferred_entry_dec(h->all_io_entry, &work);

		spin_lock_irqsave(&pool->lock, flags);

		list_for_each_entry_safe(m, tmp, &work, list)

			list_add(&m->list, &pool->prepared_discards);
@@ -3128,9 +3173,7 @@ static int __init dm_thin_init(void) 


	r = -ENOMEM;



	_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);

	if (!_cell_cache)

		goto bad_cell_cache;

	dm_bio_prison_init();



	_new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);

	if (!_new_mapping_cache)
@@ -3145,8 +3188,6 @@ static int __init dm_thin_init(void) 
bad_endio_hook_cache:

	kmem_cache_destroy(_new_mapping_cache);

bad_new_mapping_cache:

	kmem_cache_destroy(_cell_cache);

bad_cell_cache:

	dm_unregister_target(&pool_target);

bad_pool_target:

	dm_unregister_target(&thin_target);
@@ -3159,7 +3200,7 @@ static void dm_thin_exit(void) 
	dm_unregister_target(&thin_target);

	dm_unregister_target(&pool_target);



	kmem_cache_destroy(_cell_cache);

	dm_bio_prison_exit();

	kmem_cache_destroy(_new_mapping_cache);

	kmem_cache_destroy(_endio_hook_cache);

}