Merge tag 'dm-3.10-changes-2' of git://git.kernel.org/pub/scm/linux/k…

…ernel/git/agk/linux-dm

Pull device-mapper updates from Alasdair Kergon:
 "Allow devices that hold metadata for the device-mapper thin
  provisioning target to be extended easily; allow WRITE SAME on
  multipath devices; an assortment of little fixes and clean-ups."

* tag 'dm-3.10-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (21 commits)
  dm cache: set config value
  dm cache: move config fns
  dm thin: generate event when metadata threshold passed
  dm persistent metadata: add space map threshold callback
  dm persistent data: add threshold callback to space map
  dm thin: detect metadata device resizing
  dm persistent data: support space map resizing
  dm thin: open dev read only when possible
  dm thin: refactor data dev resize
  dm cache: replace memcpy with struct assignment
  dm cache: fix typos in comments
  dm cache policy: fix description of lookup fn
  dm: document iterate_devices
  dm persistent data: fix error message typos
  dm cache: tune migration throttling
  dm mpath: enable WRITE SAME support
  dm table: fix write same support
  dm bufio: avoid a possible __vmalloc deadlock
  dm snapshot: fix error return code in snapshot_ctr
  dm cache: fix error return code in cache_create
  ...

drivers/md/dm-bufio.c

@@ -319,6 +319,9 @@ static void __cache_size_refresh(void)
 static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
 			       enum data_mode *data_mode)
 {
+	unsigned noio_flag;
+	void *ptr;
+
 	if (c->block_size <= DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT) {
 		*data_mode = DATA_MODE_SLAB;
 		return kmem_cache_alloc(DM_BUFIO_CACHE(c), gfp_mask);
@@ -332,7 +335,26 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
 	}
 
 	*data_mode = DATA_MODE_VMALLOC;
-	return __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
+
+	/*
+	 * __vmalloc allocates the data pages and auxiliary structures with
+	 * gfp_flags that were specified, but pagetables are always allocated
+	 * with GFP_KERNEL, no matter what was specified as gfp_mask.
+	 *
+	 * Consequently, we must set per-process flag PF_MEMALLOC_NOIO so that
+	 * all allocations done by this process (including pagetables) are done
+	 * as if GFP_NOIO was specified.
+	 */
+
+	if (gfp_mask & __GFP_NORETRY)
+		noio_flag = memalloc_noio_save();
+
+	ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
+
+	if (gfp_mask & __GFP_NORETRY)
+		memalloc_noio_restore(noio_flag);
+
+	return ptr;
 }
 
 /*

drivers/md/dm-cache-metadata.c

@@ -1044,15 +1044,15 @@ void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
 				 struct dm_cache_statistics *stats)
 {
 	down_read(&cmd->root_lock);
-	memcpy(stats, &cmd->stats, sizeof(*stats));
+	*stats = cmd->stats;
 	up_read(&cmd->root_lock);
 }
 
 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
 				 struct dm_cache_statistics *stats)
 {
 	down_write(&cmd->root_lock);
-	memcpy(&cmd->stats, stats, sizeof(*stats));
+	cmd->stats = *stats;
 	up_write(&cmd->root_lock);
 }
 

drivers/md/dm-cache-policy.h

@@ -130,8 +130,8 @@ struct dm_cache_policy {
 	 *
 	 * Must not block.
 	 *
-	 * Returns 1 iff in cache, 0 iff not, < 0 on error (-EWOULDBLOCK
-	 * would be typical).
+	 * Returns 0 if in cache, -ENOENT if not, < 0 for other errors
+	 * (-EWOULDBLOCK would be typical).
 	 */
 	int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock);
 

drivers/md/dm-cache-target.c

@@ -205,7 +205,7 @@ struct per_bio_data {
 	/*
 	 * writethrough fields.  These MUST remain at the end of this
 	 * structure and the 'cache' member must be the first as it
-	 * is used to determine the offsetof the writethrough fields.
+	 * is used to determine the offset of the writethrough fields.
 	 */
 	struct cache *cache;
 	dm_cblock_t cblock;
@@ -393,7 +393,7 @@ static int get_cell(struct cache *cache,
 	return r;
 }
 
- /*----------------------------------------------------------------*/
+/*----------------------------------------------------------------*/
 
 static bool is_dirty(struct cache *cache, dm_cblock_t b)
 {
@@ -419,6 +419,7 @@ static void clear_dirty(struct cache *cache, dm_oblock_t oblock, dm_cblock_t cbl
 }
 
 /*----------------------------------------------------------------*/
+
 static bool block_size_is_power_of_two(struct cache *cache)
 {
 	return cache->sectors_per_block_shift >= 0;
@@ -667,7 +668,7 @@ static void writethrough_endio(struct bio *bio, int err)
 
 	/*
 	 * We can't issue this bio directly, since we're in interrupt
-	 * context.  So it get's put on a bio list for processing by the
+	 * context.  So it gets put on a bio list for processing by the
 	 * worker thread.
 	 */
 	defer_writethrough_bio(pb->cache, bio);
@@ -1445,6 +1446,7 @@ static void do_worker(struct work_struct *ws)
 static void do_waker(struct work_struct *ws)
 {
 	struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker);
+	policy_tick(cache->policy);
 	wake_worker(cache);
 	queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD);
 }
@@ -1809,7 +1811,37 @@ static int parse_cache_args(struct cache_args *ca, int argc, char **argv,
 
 static struct kmem_cache *migration_cache;
 
-static int set_config_values(struct dm_cache_policy *p, int argc, const char **argv)
+#define NOT_CORE_OPTION 1
+
+static int process_config_option(struct cache *cache, const char *key, const char *value)
+{
+	unsigned long tmp;
+
+	if (!strcasecmp(key, "migration_threshold")) {
+		if (kstrtoul(value, 10, &tmp))
+			return -EINVAL;
+
+		cache->migration_threshold = tmp;
+		return 0;
+	}
+
+	return NOT_CORE_OPTION;
+}
+
+static int set_config_value(struct cache *cache, const char *key, const char *value)
+{
+	int r = process_config_option(cache, key, value);
+
+	if (r == NOT_CORE_OPTION)
+		r = policy_set_config_value(cache->policy, key, value);
+
+	if (r)
+		DMWARN("bad config value for %s: %s", key, value);
+
+	return r;
+}
+
+static int set_config_values(struct cache *cache, int argc, const char **argv)
 {
 	int r = 0;
 
@@ -1819,12 +1851,9 @@ static int set_config_values(struct dm_cache_policy *p, int argc, const char **a
 	}
 
 	while (argc) {
-		r = policy_set_config_value(p, argv[0], argv[1]);
-		if (r) {
-			DMWARN("policy_set_config_value failed: key = '%s', value = '%s'",
-			       argv[0], argv[1]);
-			return r;
-		}
+		r = set_config_value(cache, argv[0], argv[1]);
+		if (r)
+			break;
 
 		argc -= 2;
 		argv += 2;
@@ -1836,8 +1865,6 @@ static int set_config_values(struct dm_cache_policy *p, int argc, const char **a
 static int create_cache_policy(struct cache *cache, struct cache_args *ca,
 			       char **error)
 {
-	int r;
-
 	cache->policy =	dm_cache_policy_create(ca->policy_name,
 					       cache->cache_size,
 					       cache->origin_sectors,
@@ -1847,14 +1874,7 @@ static int create_cache_policy(struct cache *cache, struct cache_args *ca,
 		return -ENOMEM;
 	}
 
-	r = set_config_values(cache->policy, ca->policy_argc, ca->policy_argv);
-	if (r) {
-		*error = "Error setting cache policy's config values";
-		dm_cache_policy_destroy(cache->policy);
-		cache->policy = NULL;
-	}
-
-	return r;
+	return 0;
 }
 
 /*
@@ -1886,7 +1906,7 @@ static sector_t calculate_discard_block_size(sector_t cache_block_size,
 	return discard_block_size;
 }
 
-#define DEFAULT_MIGRATION_THRESHOLD (2048 * 100)
+#define DEFAULT_MIGRATION_THRESHOLD 2048
 
 static int cache_create(struct cache_args *ca, struct cache **result)
 {
@@ -1911,7 +1931,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 	ti->discards_supported = true;
 	ti->discard_zeroes_data_unsupported = true;
 
-	memcpy(&cache->features, &ca->features, sizeof(cache->features));
+	cache->features = ca->features;
 	ti->per_bio_data_size = get_per_bio_data_size(cache);
 
 	cache->callbacks.congested_fn = cache_is_congested;
@@ -1948,7 +1968,15 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 	r = create_cache_policy(cache, ca, error);
 	if (r)
 		goto bad;
+
 	cache->policy_nr_args = ca->policy_argc;
+	cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD;
+
+	r = set_config_values(cache, ca->policy_argc, ca->policy_argv);
+	if (r) {
+		*error = "Error setting cache policy's config values";
+		goto bad;
+	}
 
 	cmd = dm_cache_metadata_open(cache->metadata_dev->bdev,
 				     ca->block_size, may_format,
@@ -1967,10 +1995,10 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 	INIT_LIST_HEAD(&cache->quiesced_migrations);
 	INIT_LIST_HEAD(&cache->completed_migrations);
 	INIT_LIST_HEAD(&cache->need_commit_migrations);
-	cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD;
 	atomic_set(&cache->nr_migrations, 0);
 	init_waitqueue_head(&cache->migration_wait);
 
+	r = -ENOMEM;
 	cache->nr_dirty = 0;
 	cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size));
 	if (!cache->dirty_bitset) {
@@ -2517,41 +2545,19 @@ static void cache_status(struct dm_target *ti, status_type_t type,
 	DMEMIT("Error");
 }
 
-#define NOT_CORE_OPTION 1
-
-static int process_config_option(struct cache *cache, char **argv)
-{
-	unsigned long tmp;
-
-	if (!strcasecmp(argv[0], "migration_threshold")) {
-		if (kstrtoul(argv[1], 10, &tmp))
-			return -EINVAL;
-
-		cache->migration_threshold = tmp;
-		return 0;
-	}
-
-	return NOT_CORE_OPTION;
-}
-
 /*
  * Supports <key> <value>.
  *
  * The key migration_threshold is supported by the cache target core.
  */
 static int cache_message(struct dm_target *ti, unsigned argc, char **argv)
 {
-	int r;
 	struct cache *cache = ti->private;
 
 	if (argc != 2)
 		return -EINVAL;
 
-	r = process_config_option(cache, argv);
-	if (r == NOT_CORE_OPTION)
-		return policy_set_config_value(cache->policy, argv[0], argv[1]);
-
-	return r;
+	return set_config_value(cache, argv[0], argv[1]);
 }
 
 static int cache_iterate_devices(struct dm_target *ti,
@@ -2609,7 +2615,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type cache_target = {
 	.name = "cache",
-	.version = {1, 1, 0},
+	.version = {1, 1, 1},
 	.module = THIS_MODULE,
 	.ctr = cache_ctr,
 	.dtr = cache_dtr,

drivers/md/dm-mpath.c

@@ -907,6 +907,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
 
 	ti->num_flush_bios = 1;
 	ti->num_discard_bios = 1;
+	ti->num_write_same_bios = 1;
 
 	return 0;
 

drivers/md/dm-snap.c

@@ -1121,6 +1121,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	s->pending_pool = mempool_create_slab_pool(MIN_IOS, pending_cache);
 	if (!s->pending_pool) {
 		ti->error = "Could not allocate mempool for pending exceptions";
+		r = -ENOMEM;
 		goto bad_pending_pool;
 	}
 

drivers/md/dm-stripe.c

@@ -94,7 +94,7 @@ static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
 static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct stripe_c *sc;
-	sector_t width;
+	sector_t width, tmp_len;
 	uint32_t stripes;
 	uint32_t chunk_size;
 	int r;
@@ -116,15 +116,16 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 
 	width = ti->len;
-	if (sector_div(width, chunk_size)) {
+	if (sector_div(width, stripes)) {
 		ti->error = "Target length not divisible by "
-		    "chunk size";
+		    "number of stripes";
 		return -EINVAL;
 	}
 
-	if (sector_div(width, stripes)) {
+	tmp_len = width;
+	if (sector_div(tmp_len, chunk_size)) {
 		ti->error = "Target length not divisible by "
-		    "number of stripes";
+		    "chunk size";
 		return -EINVAL;
 	}
 

drivers/md/dm-table.c

@@ -1442,7 +1442,7 @@ static bool dm_table_supports_write_same(struct dm_table *t)
 			return false;
 
 		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
+		    ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
 			return false;
 	}