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Commit d0216849 authored by Jonathan Brassow's avatar Jonathan Brassow Committed by Alasdair G Kergon
Browse files

dm exception store: move chunk_fields 



Move chunk fields 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 0cea9c78

drivers/md/dm-exception-store.c

+6 −0
Original line number Diff line number Diff line
@@ -138,6 +138,8 @@ int dm_exception_store_type_unregister(struct dm_exception_store_type *type) 
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,

			      struct dm_exception_store **store)

{

	int r = 0;
@@ -157,6 +159,10 @@ int dm_exception_store_create(const char *type_name, struct dm_target *ti, 
	tmp_store->type = type;

	tmp_store->ti = ti;



	tmp_store->chunk_size = chunk_size;

	tmp_store->chunk_mask = chunk_mask;

	tmp_store->chunk_shift = chunk_shift;



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

	if (r) {

		put_type(type);

drivers/md/dm-exception-store.h

+7 −0
Original line number Diff line number Diff line
@@ -99,6 +99,11 @@ struct dm_exception_store { 


	struct dm_snapshot *snap;



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

	chunk_t chunk_size;

	chunk_t chunk_mask;

	chunk_t chunk_shift;



	void *context;

};
@@ -149,6 +154,8 @@ int dm_exception_store_type_register(struct dm_exception_store_type *type); 
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,

			      struct dm_exception_store **store);

void dm_exception_store_destroy(struct dm_exception_store *store);

drivers/md/dm-snap-persistent.c

+24 −23
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ static int alloc_area(struct pstore *ps) 
	int r = -ENOMEM;

	size_t len;



	len = ps->snap->chunk_size << SECTOR_SHIFT;

	len = ps->snap->store->chunk_size << SECTOR_SHIFT;



	/*

	 * Allocate the chunk_size block of memory that will hold
@@ -190,8 +190,8 @@ static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata) 
{

	struct dm_io_region where = {

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

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

		.count = ps->snap->chunk_size,

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

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

	};

	struct dm_io_request io_req = {

		.bi_rw = rw,
@@ -247,15 +247,15 @@ static int area_io(struct pstore *ps, int rw) 


static void zero_memory_area(struct pstore *ps)

{

	memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);

	memset(ps->area, 0, ps->snap->store->chunk_size << SECTOR_SHIFT);

}



static int zero_disk_area(struct pstore *ps, chunk_t area)

{

	struct dm_io_region where = {

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

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

		.count = ps->snap->chunk_size,

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

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

	};

	struct dm_io_request io_req = {

		.bi_rw = WRITE,
@@ -278,16 +278,17 @@ static int read_header(struct pstore *ps, int *new_snapshot) 
	/*

	 * Use default chunk size (or hardsect_size, if larger) if none supplied

	 */

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

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

	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);

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

		ps->snap->chunk_shift = ffs(ps->snap->chunk_size) - 1;

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

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

					       - 1;

		chunk_size_supplied = 0;

	}



	ps->io_client = dm_io_client_create(sectors_to_pages(ps->snap->

							     chunk_size));

							    store->chunk_size));

	if (IS_ERR(ps->io_client))

		return PTR_ERR(ps->io_client);
@@ -317,22 +318,22 @@ static int read_header(struct pstore *ps, int *new_snapshot) 
	ps->version = le32_to_cpu(dh->version);

	chunk_size = le32_to_cpu(dh->chunk_size);



	if (!chunk_size_supplied || ps->snap->chunk_size == chunk_size)

	if (!chunk_size_supplied || ps->snap->store->chunk_size == chunk_size)

		return 0;



	DMWARN("chunk size %llu in device metadata overrides "

	       "table chunk size of %llu.",

	       (unsigned long long)chunk_size,

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

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



	/* We had a bogus chunk_size. Fix stuff up. */

	free_area(ps);



	ps->snap->chunk_size = chunk_size;

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

	ps->snap->chunk_shift = ffs(chunk_size) - 1;

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

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

	ps->snap->store->chunk_shift = ffs(chunk_size) - 1;



	r = dm_io_client_resize(sectors_to_pages(ps->snap->chunk_size),

	r = dm_io_client_resize(sectors_to_pages(ps->snap->store->chunk_size),

				ps->io_client);

	if (r)

		return r;
@@ -349,13 +350,13 @@ static int write_header(struct pstore *ps) 
{

	struct disk_header *dh;



	memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);

	memset(ps->area, 0, ps->snap->store->chunk_size << SECTOR_SHIFT);



	dh = (struct disk_header *) ps->area;

	dh->magic = cpu_to_le32(SNAP_MAGIC);

	dh->valid = cpu_to_le32(ps->valid);

	dh->version = cpu_to_le32(ps->version);

	dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);

	dh->chunk_size = cpu_to_le32(ps->snap->store->chunk_size);



	return chunk_io(ps, 0, WRITE, 1);

}
@@ -474,7 +475,7 @@ static struct pstore *get_info(struct dm_exception_store *store) 
static void persistent_fraction_full(struct dm_exception_store *store,

				     sector_t *numerator, sector_t *denominator)

{

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

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

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

}
@@ -507,8 +508,8 @@ static int persistent_read_metadata(struct dm_exception_store *store, 
	/*

	 * Now we know correct chunk_size, complete the initialisation.

	 */

	ps->exceptions_per_area = (ps->snap->chunk_size << SECTOR_SHIFT) /

				  sizeof(struct disk_exception);

	ps->exceptions_per_area = (ps->snap->store->chunk_size << SECTOR_SHIFT)

				  / sizeof(struct disk_exception);

	ps->callbacks = dm_vcalloc(ps->exceptions_per_area,

			sizeof(*ps->callbacks));

	if (!ps->callbacks)
@@ -567,7 +568,7 @@ static int persistent_prepare_exception(struct dm_exception_store *store, 
	sector_t size = get_dev_size(store->snap->cow->bdev);



	/* Is there enough room ? */

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

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

		return -ENOSPC;



	e->new_chunk = ps->next_free;

drivers/md/dm-snap-transient.c

+2 −2
Original line number Diff line number Diff line
@@ -42,11 +42,11 @@ static int transient_prepare_exception(struct dm_exception_store *store, 
	struct transient_c *tc = store->context;

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



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

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

		return -1;



	e->new_chunk = sector_to_chunk(store->snap, tc->next_free);

	tc->next_free += store->snap->chunk_size;

	tc->next_free += store->chunk_size;



	return 0;

}

drivers/md/dm-snap.c

+26 −21
Original line number Diff line number Diff line
@@ -468,7 +468,7 @@ static int calc_max_buckets(void) 
/*

 * Allocate room for a suitable hash table.

 */

static int init_hash_tables(struct dm_snapshot *s)

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

{

	sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
@@ -480,7 +480,7 @@ static int init_hash_tables(struct dm_snapshot *s) 
	origin_dev_size = get_dev_size(s->origin->bdev);

	max_buckets = calc_max_buckets();



	hash_size = min(origin_dev_size, cow_dev_size) >> s->chunk_shift;

	hash_size = min(origin_dev_size, cow_dev_size) >> chunk_shift;

	hash_size = min(hash_size, max_buckets);



	hash_size = rounddown_pow_of_two(hash_size);
@@ -515,19 +515,20 @@ static ulong round_up(ulong n, ulong size) 
}



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

			  char **error)

			  chunk_t *chunk_size, chunk_t *chunk_mask,

			  chunk_t *chunk_shift, char **error)

{

	unsigned long chunk_size;

	unsigned long chunk_size_ulong;

	char *value;



	chunk_size = simple_strtoul(chunk_size_arg, &value, 10);

	chunk_size_ulong = simple_strtoul(chunk_size_arg, &value, 10);

	if (*chunk_size_arg == '\0' || *value != '\0') {

		*error = "Invalid chunk size";

		return -EINVAL;

	}



	if (!chunk_size) {

		s->chunk_size = s->chunk_mask = s->chunk_shift = 0;

	if (!chunk_size_ulong) {

		*chunk_size = *chunk_mask = *chunk_shift = 0;

		return 0;

	}
@@ -535,23 +536,23 @@ static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg, 
	 * Chunk size must be multiple of page size.  Silently

	 * round up if it's not.

	 */

	chunk_size = round_up(chunk_size, PAGE_SIZE >> 9);

	chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);



	/* Check chunk_size is a power of 2 */

	if (!is_power_of_2(chunk_size)) {

	if (!is_power_of_2(chunk_size_ulong)) {

		*error = "Chunk size is not a power of 2";

		return -EINVAL;

	}



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

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

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

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

		return -EINVAL;

	}



	s->chunk_size = chunk_size;

	s->chunk_mask = chunk_size - 1;

	s->chunk_shift = ffs(chunk_size) - 1;

	*chunk_size = chunk_size_ulong;

	*chunk_mask = chunk_size_ulong - 1;

	*chunk_shift = ffs(chunk_size_ulong) - 1;



	return 0;

}
@@ -567,6 +568,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	char persistent;

	char *origin_path;

	char *cow_path;

	chunk_t chunk_size, chunk_mask, chunk_shift;



	if (argc != 4) {

		ti->error = "requires exactly 4 arguments";
@@ -606,7 +608,8 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		goto bad2;

	}



	r = set_chunk_size(s, argv[3], &ti->error);

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

			   &ti->error);

	if (r)

		goto bad3;
@@ -617,13 +620,14 @@ 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)) {

	if (init_hash_tables(s, chunk_shift)) {

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

		r = -ENOMEM;

		goto bad3;

	}



	r = dm_exception_store_create(argv[2], ti, &s->store);

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

				      chunk_shift, &s->store);

	if (r) {

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

		r = -EINVAL;
@@ -680,7 +684,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	}



	ti->private = s;

	ti->split_io = s->chunk_size;

	ti->split_io = s->store->chunk_size;



	return 0;
@@ -955,7 +959,7 @@ static void start_copy(struct dm_snap_pending_exception *pe) 


	src.bdev = bdev;

	src.sector = chunk_to_sector(s, pe->e.old_chunk);

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

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



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

	dest.sector = chunk_to_sector(s, pe->e.new_chunk);
@@ -1021,7 +1025,7 @@ static void remap_exception(struct dm_snapshot *s, struct dm_snap_exception *e, 
	bio->bi_bdev = s->cow->bdev;

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

			 (chunk - e->old_chunk)) +

			 (bio->bi_sector & s->chunk_mask);

			 (bio->bi_sector & s->store->chunk_mask);

}



static int snapshot_map(struct dm_target *ti, struct bio *bio,
@@ -1166,7 +1170,7 @@ static int snapshot_status(struct dm_target *ti, status_type_t type, 
		snprintf(result, maxlen, "%s %s %s %llu",

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

			 snap->store->type->name,

			 (unsigned long long)snap->chunk_size);

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

		break;

	}
@@ -1377,7 +1381,8 @@ static void origin_resume(struct dm_target *ti) 
	o = __lookup_origin(dev->bdev);

	if (o)

		list_for_each_entry (snap, &o->snapshots, list)

			chunk_size = min_not_zero(chunk_size, snap->chunk_size);

			chunk_size = min_not_zero(chunk_size,

						  snap->store->chunk_size);

	up_read(&_origins_lock);



	ti->split_io = chunk_size;