From d0216849519bec8dc96301a3cd80316e71243839 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 2 Apr 2009 19:55:32 +0100 Subject: dm exception store: move chunk_fields Move chunk fields from snapshot to exception store. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon --- drivers/md/dm-snap.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-) (limited to 'drivers/md/dm-snap.c') diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 4429c2a..7a90fed 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -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; -- cgit v1.1