From fee1998e9c690f9920671e1e0ef187a48cfbbde4 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 2 Apr 2009 19:55:34 +0100 Subject: dm snapshot: move ctr parsing to exception store First step of having the exception stores parse their own arguments - generalizing the interface. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon --- drivers/md/dm-exception-store.c | 109 +++++++++++++++++++++++++---- drivers/md/dm-exception-store.h | 5 +- drivers/md/dm-snap.c | 147 ++++++++++------------------------------ 3 files changed, 132 insertions(+), 129 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c index 2078b92..a2e26c2 100644 --- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -7,6 +7,7 @@ #include "dm-exception-store.h" +#include #include #include #include @@ -137,49 +138,129 @@ 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_dev *cow, +/* + * Round a number up to the nearest 'size' boundary. size must + * be a power of 2. + */ +static ulong round_up(ulong n, ulong size) +{ + size--; + return (n + size) & ~size; +} + +static int set_chunk_size(struct dm_exception_store *store, + const char *chunk_size_arg, char **error) +{ + unsigned long chunk_size_ulong; + char *value; + + 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_ulong) { + store->chunk_size = store->chunk_mask = store->chunk_shift = 0; + return 0; + } + + /* + * Chunk size must be multiple of page size. Silently + * round up if it's not. + */ + 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_ulong)) { + *error = "Chunk size is not a power of 2"; + return -EINVAL; + } + + /* Validate the chunk size against the device block size */ + if (chunk_size_ulong % (bdev_hardsect_size(store->cow->bdev) >> 9)) { + *error = "Chunk size is not a multiple of device blocksize"; + return -EINVAL; + } + + store->chunk_size = chunk_size_ulong; + store->chunk_mask = chunk_size_ulong - 1; + store->chunk_shift = ffs(chunk_size_ulong) - 1; + + return 0; +} + +int dm_exception_store_create(struct dm_target *ti, int argc, char **argv, + unsigned *args_used, struct dm_exception_store **store) { int r = 0; struct dm_exception_store_type *type; struct dm_exception_store *tmp_store; + char persistent; + + if (argc < 3) { + ti->error = "Insufficient exception store arguments"; + return -EINVAL; + } tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL); - if (!tmp_store) + if (!tmp_store) { + ti->error = "Exception store allocation failed"; return -ENOMEM; + } - type = get_type(type_name); - if (!type) { - kfree(tmp_store); + persistent = toupper(*argv[1]); + if (persistent != 'P' && persistent != 'N') { + ti->error = "Persistent flag is not P or N"; return -EINVAL; } + type = get_type(argv[1]); + if (!type) { + ti->error = "Exception store type not recognised"; + r = -EINVAL; + goto bad_type; + } + 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 = dm_get_device(ti, argv[0], 0, 0, + FMODE_READ | FMODE_WRITE, &tmp_store->cow); + if (r) { + ti->error = "Cannot get COW device"; + goto bad_cow; + } - tmp_store->cow = cow; + r = set_chunk_size(tmp_store, argv[2], &ti->error); + if (r) + goto bad_cow; r = type->ctr(tmp_store, 0, NULL); if (r) { - put_type(type); - kfree(tmp_store); - return r; + ti->error = "Exception store type constructor failed"; + goto bad_ctr; } + *args_used = 3; *store = tmp_store; return 0; + +bad_ctr: + dm_put_device(ti, tmp_store->cow); +bad_cow: + put_type(type); +bad_type: + kfree(tmp_store); + return r; } EXPORT_SYMBOL(dm_exception_store_create); void dm_exception_store_destroy(struct dm_exception_store *store) { store->type->dtr(store); + dm_put_device(store->ti, store->cow); put_type(store->type); kfree(store); } diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h index 835f402..023a707 100644 --- a/drivers/md/dm-exception-store.h +++ b/drivers/md/dm-exception-store.h @@ -167,9 +167,8 @@ static inline chunk_t sector_to_chunk(struct dm_exception_store *store, 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_dev *cow, +int dm_exception_store_create(struct dm_target *ti, int argc, char **argv, + unsigned *args_used, struct dm_exception_store **store); void dm_exception_store_destroy(struct dm_exception_store *store); diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index fcb1ac1..974916b 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -7,7 +7,6 @@ */ #include -#include #include #include #include @@ -538,8 +537,7 @@ 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, - struct dm_dev *cow) +static int init_hash_tables(struct dm_snapshot *s) { sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets; @@ -547,11 +545,11 @@ 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(cow->bdev); + cow_dev_size = get_dev_size(s->store->cow->bdev); origin_dev_size = get_dev_size(s->origin->bdev); max_buckets = calc_max_buckets(); - hash_size = min(origin_dev_size, cow_dev_size) >> chunk_shift; + hash_size = min(origin_dev_size, cow_dev_size) >> s->store->chunk_shift; hash_size = min(hash_size, max_buckets); hash_size = rounddown_pow_of_two(hash_size); @@ -576,60 +574,6 @@ static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift, } /* - * Round a number up to the nearest 'size' boundary. size must - * be a power of 2. - */ -static ulong round_up(ulong n, ulong size) -{ - size--; - return (n + size) & ~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, struct dm_dev *cow, - char **error) -{ - unsigned long chunk_size_ulong; - char *value; - - 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_ulong) { - *chunk_size = *chunk_mask = *chunk_shift = 0; - return 0; - } - - /* - * Chunk size must be multiple of page size. Silently - * round up if it's not. - */ - 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_ulong)) { - *error = "Chunk size is not a power of 2"; - return -EINVAL; - } - - /* Validate the chunk size against the device block size */ - if (chunk_size_ulong % (bdev_hardsect_size(cow->bdev) >> 9)) { - *error = "Chunk size is not a multiple of device blocksize"; - return -EINVAL; - } - - *chunk_size = chunk_size_ulong; - *chunk_mask = chunk_size_ulong - 1; - *chunk_shift = ffs(chunk_size_ulong) - 1; - - return 0; -} - -/* * Construct a snapshot mapping:

*/ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) @@ -637,55 +581,45 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) struct dm_snapshot *s; int i; int r = -EINVAL; - char persistent; char *origin_path; - char *cow_path; - chunk_t chunk_size, chunk_mask, chunk_shift; - struct dm_dev *cow; + struct dm_exception_store *store; + unsigned args_used; if (argc != 4) { ti->error = "requires exactly 4 arguments"; r = -EINVAL; - goto bad1; + goto bad_args; } origin_path = argv[0]; - cow_path = argv[1]; - persistent = toupper(*argv[2]); + argv++; + argc--; - if (persistent != 'P' && persistent != 'N') { - ti->error = "Persistent flag is not P or N"; + r = dm_exception_store_create(ti, argc, argv, &args_used, &store); + if (r) { + ti->error = "Couldn't create exception store"; r = -EINVAL; - goto bad1; + goto bad_args; } + argv += args_used; + argc -= args_used; + s = kmalloc(sizeof(*s), GFP_KERNEL); - if (s == NULL) { + if (!s) { ti->error = "Cannot allocate snapshot context private " "structure"; r = -ENOMEM; - goto bad1; + goto bad_snap; } r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin); if (r) { ti->error = "Cannot get origin device"; - goto bad2; + goto bad_origin; } - r = dm_get_device(ti, cow_path, 0, 0, - FMODE_READ | FMODE_WRITE, &cow); - if (r) { - dm_put_device(ti, s->origin); - ti->error = "Cannot get COW device"; - goto bad2; - } - - r = set_chunk_size(s, argv[3], &chunk_size, &chunk_mask, &chunk_shift, - cow, &ti->error); - if (r) - goto bad3; - + s->store = store; s->valid = 1; s->active = 0; atomic_set(&s->pending_exceptions_count, 0); @@ -693,30 +627,22 @@ 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, cow)) { + if (init_hash_tables(s)) { 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, cow, &s->store); - if (r) { - ti->error = "Couldn't create exception store"; - r = -EINVAL; - goto bad4; + goto bad_hash_tables; } r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client); if (r) { ti->error = "Could not create kcopyd client"; - goto bad5; + goto bad_kcopyd; } s->pending_pool = mempool_create_slab_pool(MIN_IOS, pending_cache); if (!s->pending_pool) { ti->error = "Could not allocate mempool for pending exceptions"; - goto bad6; + goto bad_pending_pool; } s->tracked_chunk_pool = mempool_create_slab_pool(MIN_IOS, @@ -759,30 +685,29 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) return 0; - bad_load_and_register: +bad_load_and_register: mempool_destroy(s->tracked_chunk_pool); - bad_tracked_chunk_pool: +bad_tracked_chunk_pool: mempool_destroy(s->pending_pool); - bad6: +bad_pending_pool: dm_kcopyd_client_destroy(s->kcopyd_client); - bad5: - s->store->type->dtr(s->store); - - bad4: +bad_kcopyd: exit_exception_table(&s->pending, pending_cache); exit_exception_table(&s->complete, exception_cache); - bad3: - dm_put_device(ti, cow); +bad_hash_tables: dm_put_device(ti, s->origin); - bad2: +bad_origin: kfree(s); - bad1: +bad_snap: + dm_exception_store_destroy(store); + +bad_args: return r; } @@ -793,8 +718,6 @@ static void __free_exceptions(struct dm_snapshot *s) exit_exception_table(&s->pending, pending_cache); exit_exception_table(&s->complete, exception_cache); - - s->store->type->dtr(s->store); } static void snapshot_dtr(struct dm_target *ti) @@ -803,7 +726,6 @@ 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); @@ -831,7 +753,8 @@ static void snapshot_dtr(struct dm_target *ti) mempool_destroy(s->pending_pool); dm_put_device(ti, s->origin); - dm_put_device(ti, cow); + + dm_exception_store_destroy(s->store); kfree(s); } -- cgit v1.1