Commit 49beb2b8 authored by Jonathan Brassow's avatar Jonathan Brassow Committed by Alasdair G Kergon
Browse files

dm exception store: move cow pointer 



Move COW device from snapshot to exception store.

Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent d0216849

drivers/md/dm-exception-store.c

+3 −1
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ EXPORT_SYMBOL(dm_exception_store_type_unregister); 


int dm_exception_store_create(const char *type_name, struct dm_target *ti,

			      chunk_t chunk_size, chunk_t chunk_mask,

			      chunk_t chunk_shift,

			      chunk_t chunk_shift, struct dm_dev *cow,

			      struct dm_exception_store **store)

{

	int r = 0;
@@ -163,6 +163,8 @@ int dm_exception_store_create(const char *type_name, struct dm_target *ti, 
	tmp_store->chunk_mask = chunk_mask;

	tmp_store->chunk_shift = chunk_shift;



	tmp_store->cow = cow;



	r = type->ctr(tmp_store, 0, NULL);

	if (r) {

		put_type(type);

drivers/md/dm-exception-store.h

+3 −1
Original line number Diff line number Diff line
@@ -99,6 +99,8 @@ struct dm_exception_store { 


	struct dm_snapshot *snap;



	struct dm_dev *cow;



	/* Size of data blocks saved - must be a power of 2 */

	chunk_t chunk_size;

	chunk_t chunk_mask;
@@ -155,7 +157,7 @@ int dm_exception_store_type_unregister(struct dm_exception_store_type *type); 


int dm_exception_store_create(const char *type_name, struct dm_target *ti,

			      chunk_t chunk_size, chunk_t chunk_mask,

			      chunk_t chunk_shift,

			      chunk_t chunk_shift, struct dm_dev *cow,

			      struct dm_exception_store **store);

void dm_exception_store_destroy(struct dm_exception_store *store);

drivers/md/dm-snap-persistent.c

+5 −5
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ static void do_metadata(struct work_struct *work) 
static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)

{

	struct dm_io_region where = {

		.bdev = ps->snap->cow->bdev,

		.bdev = ps->snap->store->cow->bdev,

		.sector = ps->snap->store->chunk_size * chunk,

		.count = ps->snap->store->chunk_size,

	};
@@ -253,7 +253,7 @@ static void zero_memory_area(struct pstore *ps) 
static int zero_disk_area(struct pstore *ps, chunk_t area)

{

	struct dm_io_region where = {

		.bdev = ps->snap->cow->bdev,

		.bdev = ps->snap->store->cow->bdev,

		.sector = ps->snap->store->chunk_size * area_location(ps, area),

		.count = ps->snap->store->chunk_size,

	};
@@ -280,7 +280,7 @@ static int read_header(struct pstore *ps, int *new_snapshot) 
	 */

	if (!ps->snap->store->chunk_size) {

		ps->snap->store->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,

		    bdev_hardsect_size(ps->snap->cow->bdev) >> 9);

		    bdev_hardsect_size(ps->snap->store->cow->bdev) >> 9);

		ps->snap->store->chunk_mask = ps->snap->store->chunk_size - 1;

		ps->snap->store->chunk_shift = ffs(ps->snap->store->chunk_size)

					       - 1;
@@ -476,7 +476,7 @@ static void persistent_fraction_full(struct dm_exception_store *store, 
				     sector_t *numerator, sector_t *denominator)

{

	*numerator = get_info(store)->next_free * store->chunk_size;

	*denominator = get_dev_size(store->snap->cow->bdev);

	*denominator = get_dev_size(store->cow->bdev);

}



static void persistent_dtr(struct dm_exception_store *store)
@@ -565,7 +565,7 @@ static int persistent_prepare_exception(struct dm_exception_store *store, 
	struct pstore *ps = get_info(store);

	uint32_t stride;

	chunk_t next_free;

	sector_t size = get_dev_size(store->snap->cow->bdev);

	sector_t size = get_dev_size(store->cow->bdev);



	/* Is there enough room ? */

	if (size < ((ps->next_free + 1) * store->chunk_size))

drivers/md/dm-snap-transient.c

+2 −2
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ static int transient_prepare_exception(struct dm_exception_store *store, 
				       struct dm_snap_exception *e)

{

	struct transient_c *tc = store->context;

	sector_t size = get_dev_size(store->snap->cow->bdev);

	sector_t size = get_dev_size(store->cow->bdev);



	if (size < (tc->next_free + store->chunk_size))

		return -1;
@@ -64,7 +64,7 @@ static void transient_fraction_full(struct dm_exception_store *store, 
				    sector_t *numerator, sector_t *denominator)

{

	*numerator = ((struct transient_c *) store->context)->next_free;

	*denominator = get_dev_size(store->snap->cow->bdev);

	*denominator = get_dev_size(store->cow->bdev);

}



static int transient_ctr(struct dm_exception_store *store,

drivers/md/dm-snap.c

+17 −13
Original line number Diff line number Diff line
@@ -468,7 +468,8 @@ static int calc_max_buckets(void) 
/*

 * Allocate room for a suitable hash table.

 */

static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift)

static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift,

			    struct dm_dev *cow)

{

	sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
@@ -476,7 +477,7 @@ static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift) 
	 * Calculate based on the size of the original volume or

	 * the COW volume...

	 */

	cow_dev_size = get_dev_size(s->cow->bdev);

	cow_dev_size = get_dev_size(cow->bdev);

	origin_dev_size = get_dev_size(s->origin->bdev);

	max_buckets = calc_max_buckets();
@@ -516,7 +517,8 @@ static ulong round_up(ulong n, ulong size) 


static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg,

			  chunk_t *chunk_size, chunk_t *chunk_mask,

			  chunk_t *chunk_shift, char **error)

			  chunk_t *chunk_shift, struct dm_dev *cow,

			  char **error)

{

	unsigned long chunk_size_ulong;

	char *value;
@@ -545,7 +547,7 @@ static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg, 
	}



	/* Validate the chunk size against the device block size */

	if (chunk_size_ulong % (bdev_hardsect_size(s->cow->bdev) >> 9)) {

	if (chunk_size_ulong % (bdev_hardsect_size(cow->bdev) >> 9)) {

		*error = "Chunk size is not a multiple of device blocksize";

		return -EINVAL;

	}
@@ -569,6 +571,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	char *origin_path;

	char *cow_path;

	chunk_t chunk_size, chunk_mask, chunk_shift;

	struct dm_dev *cow;



	if (argc != 4) {

		ti->error = "requires exactly 4 arguments";
@@ -601,7 +604,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	}



	r = dm_get_device(ti, cow_path, 0, 0,

			  FMODE_READ | FMODE_WRITE, &s->cow);

			  FMODE_READ | FMODE_WRITE, &cow);

	if (r) {

		dm_put_device(ti, s->origin);

		ti->error = "Cannot get COW device";
@@ -609,7 +612,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	}



	r = set_chunk_size(s, argv[3], &chunk_size, &chunk_mask, &chunk_shift,

			   &ti->error);

			   cow, &ti->error);

	if (r)

		goto bad3;
@@ -620,14 +623,14 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	spin_lock_init(&s->pe_lock);



	/* Allocate hash table for COW data */

	if (init_hash_tables(s, chunk_shift)) {

	if (init_hash_tables(s, chunk_shift, cow)) {

		ti->error = "Unable to allocate hash table space";

		r = -ENOMEM;

		goto bad3;

	}



	r = dm_exception_store_create(argv[2], ti, chunk_size, chunk_mask,

				      chunk_shift, &s->store);

				      chunk_shift, cow, &s->store);

	if (r) {

		ti->error = "Couldn't create exception store";

		r = -EINVAL;
@@ -705,7 +708,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	exit_exception_table(&s->complete, exception_cache);



 bad3:

	dm_put_device(ti, s->cow);

	dm_put_device(ti, cow);

	dm_put_device(ti, s->origin);



 bad2:
@@ -732,6 +735,7 @@ static void snapshot_dtr(struct dm_target *ti) 
	int i;

#endif

	struct dm_snapshot *s = ti->private;

	struct dm_dev *cow = s->store->cow;



	flush_workqueue(ksnapd);
@@ -759,7 +763,7 @@ static void snapshot_dtr(struct dm_target *ti) 
	mempool_destroy(s->pending_pool);



	dm_put_device(ti, s->origin);

	dm_put_device(ti, s->cow);

	dm_put_device(ti, cow);



	kfree(s);

}
@@ -961,7 +965,7 @@ static void start_copy(struct dm_snap_pending_exception *pe) 
	src.sector = chunk_to_sector(s, pe->e.old_chunk);

	src.count = min(s->store->chunk_size, dev_size - src.sector);



	dest.bdev = s->cow->bdev;

	dest.bdev = s->store->cow->bdev;

	dest.sector = chunk_to_sector(s, pe->e.new_chunk);

	dest.count = src.count;
@@ -1022,7 +1026,7 @@ __find_pending_exception(struct dm_snapshot *s, 
static void remap_exception(struct dm_snapshot *s, struct dm_snap_exception *e,

			    struct bio *bio, chunk_t chunk)

{

	bio->bi_bdev = s->cow->bdev;

	bio->bi_bdev = s->store->cow->bdev;

	bio->bi_sector = chunk_to_sector(s, dm_chunk_number(e->new_chunk) +

			 (chunk - e->old_chunk)) +

			 (bio->bi_sector & s->store->chunk_mask);
@@ -1168,7 +1172,7 @@ static int snapshot_status(struct dm_target *ti, status_type_t type, 
		 * make sense.

		 */

		snprintf(result, maxlen, "%s %s %s %llu",

			 snap->origin->name, snap->cow->name,

			 snap->origin->name, snap->store->cow->name,

			 snap->store->type->name,

			 (unsigned long long)snap->store->chunk_size);

		break;