Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kern…

…el/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:
 "Smaller set of DM changes for this merge.  I've based these changes on
  Jens' for-4.4/reservations branch because the associated DM changes
  required it.

   - Revert a dm-multipath change that caused a regression for
     unprivledged users (e.g. kvm guests) that issued ioctls when a
     multipath device had no available paths.

   - Include Christoph's refactoring of DM's ioctl handling and add
     support for passing through persistent reservations with DM
     multipath.

   - All other changes are very simple cleanups"

* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm switch: simplify conditional in alloc_region_table()
  dm delay: document that offsets are specified in sectors
  dm delay: capitalize the start of an delay_ctr() error message
  dm delay: Use DM_MAPIO macros instead of open-coded equivalents
  dm linear: remove redundant target name from error messages
  dm persistent data: eliminate unnecessary return values
  dm: eliminate unused "bioset" process for each bio-based DM device
  dm: convert ffs to __ffs
  dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
  dm: add support for passing through persistent reservations
  dm: refactor ioctl handling
  Revert "dm mpath: fix stalls when handling invalid ioctls"
  dm: initialize non-blk-mq queue data before queue is used

Documentation/device-mapper/delay.txt

@@ -8,6 +8,7 @@ Parameters:
     <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
 
 With separate write parameters, the first set is only used for reads.
+Offsets are specified in sectors.
 Delays are specified in milliseconds.
 
 Example scripts

drivers/md/dm-bufio.c

@@ -1598,11 +1598,11 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
 
 	c->bdev = bdev;
 	c->block_size = block_size;
-	c->sectors_per_block_bits = ffs(block_size) - 1 - SECTOR_SHIFT;
-	c->pages_per_block_bits = (ffs(block_size) - 1 >= PAGE_SHIFT) ?
-				  ffs(block_size) - 1 - PAGE_SHIFT : 0;
-	c->blocks_per_page_bits = (ffs(block_size) - 1 < PAGE_SHIFT ?
-				  PAGE_SHIFT - (ffs(block_size) - 1) : 0);
+	c->sectors_per_block_bits = __ffs(block_size) - SECTOR_SHIFT;
+	c->pages_per_block_bits = (__ffs(block_size) >= PAGE_SHIFT) ?
+				  __ffs(block_size) - PAGE_SHIFT : 0;
+	c->blocks_per_page_bits = (__ffs(block_size) < PAGE_SHIFT ?
+				  PAGE_SHIFT - __ffs(block_size) : 0);
 
 	c->aux_size = aux_size;
 	c->alloc_callback = alloc_callback;
@@ -1861,12 +1861,8 @@ static void __exit dm_bufio_exit(void)
 	cancel_delayed_work_sync(&dm_bufio_work);
 	destroy_workqueue(dm_bufio_wq);
 
-	for (i = 0; i < ARRAY_SIZE(dm_bufio_caches); i++) {
-		struct kmem_cache *kc = dm_bufio_caches[i];
-
-		if (kc)
-			kmem_cache_destroy(kc);
-	}
+	for (i = 0; i < ARRAY_SIZE(dm_bufio_caches); i++)
+		kmem_cache_destroy(dm_bufio_caches[i]);
 
 	for (i = 0; i < ARRAY_SIZE(dm_bufio_cache_names); i++)
 		kfree(dm_bufio_cache_names[i]);

drivers/md/dm-cache-metadata.c

@@ -260,7 +260,9 @@ static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
 		}
 	}
 
-	return dm_bm_unlock(b);
+	dm_bm_unlock(b);
+
+	return 0;
 }
 
 static void __setup_mapping_info(struct dm_cache_metadata *cmd)
@@ -465,7 +467,9 @@ static int __open_metadata(struct dm_cache_metadata *cmd)
 	dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
 	sb_flags = le32_to_cpu(disk_super->flags);
 	cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
-	return dm_bm_unlock(sblock);
+	dm_bm_unlock(sblock);
+
+	return 0;
 
 bad:
 	dm_bm_unlock(sblock);

drivers/md/dm-cache-policy-cleaner.c

@@ -83,7 +83,7 @@ static struct list_head *list_pop(struct list_head *q)
 static int alloc_hash(struct hash *hash, unsigned elts)
 {
 	hash->nr_buckets = next_power(elts >> 4, 16);
-	hash->hash_bits = ffs(hash->nr_buckets) - 1;
+	hash->hash_bits = __ffs(hash->nr_buckets);
 	hash->table = vzalloc(sizeof(*hash->table) * hash->nr_buckets);
 
 	return hash->table ? 0 : -ENOMEM;

drivers/md/dm-cache-policy-mq.c

@@ -1410,7 +1410,7 @@ static struct dm_cache_policy *mq_create(dm_cblock_t cache_size,
 	mq->generation_period = max((unsigned) from_cblock(cache_size), 1024U);
 
 	mq->nr_buckets = next_power(from_cblock(cache_size) / 2, 16);
-	mq->hash_bits = ffs(mq->nr_buckets) - 1;
+	mq->hash_bits = __ffs(mq->nr_buckets);
 	mq->table = vzalloc(sizeof(*mq->table) * mq->nr_buckets);
 	if (!mq->table)
 		goto bad_alloc_table;

drivers/md/dm-cache-policy-smq.c

@@ -566,7 +566,7 @@ static int h_init(struct hash_table *ht, struct entry_space *es, unsigned nr_ent
 
 	ht->es = es;
 	nr_buckets = roundup_pow_of_two(max(nr_entries / 4u, 16u));
-	ht->hash_bits = ffs(nr_buckets) - 1;
+	ht->hash_bits = __ffs(nr_buckets);
 
 	ht->buckets = vmalloc(sizeof(*ht->buckets) * nr_buckets);
 	if (!ht->buckets)

drivers/md/dm-cache-target.c

@@ -2309,8 +2309,7 @@ static void destroy(struct cache *cache)
 {
 	unsigned i;
 
-	if (cache->migration_pool)
-		mempool_destroy(cache->migration_pool);
+	mempool_destroy(cache->migration_pool);
 
 	if (cache->all_io_ds)
 		dm_deferred_set_destroy(cache->all_io_ds);

drivers/md/dm-crypt.c

@@ -1544,10 +1544,8 @@ static void crypt_dtr(struct dm_target *ti)
 	if (cc->bs)
 		bioset_free(cc->bs);
 
-	if (cc->page_pool)
-		mempool_destroy(cc->page_pool);
-	if (cc->req_pool)
-		mempool_destroy(cc->req_pool);
+	mempool_destroy(cc->page_pool);
+	mempool_destroy(cc->req_pool);
 
 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
 		cc->iv_gen_ops->dtr(cc);

drivers/md/dm-delay.c

@@ -122,6 +122,7 @@ static void flush_expired_bios(struct work_struct *work)
  *    <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
  *
  * With separate write parameters, the first set is only used for reads.
+ * Offsets are specified in sectors.
  * Delays are specified in milliseconds.
  */
 static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
@@ -132,7 +133,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	int ret;
 
 	if (argc != 3 && argc != 6) {
-		ti->error = "requires exactly 3 or 6 arguments";
+		ti->error = "Requires exactly 3 or 6 arguments";
 		return -EINVAL;
 	}
 
@@ -237,7 +238,7 @@ static int delay_bio(struct delay_c *dc, int delay, struct bio *bio)
 	unsigned long expires = 0;
 
 	if (!delay || !atomic_read(&dc->may_delay))
-		return 1;
+		return DM_MAPIO_REMAPPED;
 
 	delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
 
@@ -257,7 +258,7 @@ static int delay_bio(struct delay_c *dc, int delay, struct bio *bio)
 
 	queue_timeout(dc, expires);
 
-	return 0;
+	return DM_MAPIO_SUBMITTED;
 }
 
 static void delay_presuspend(struct dm_target *ti)

drivers/md/dm-era-target.c

@@ -343,7 +343,9 @@ static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
 		}
 	}
 
-	return dm_bm_unlock(b);
+	dm_bm_unlock(b);
+
+	return 0;
 }
 
 /*----------------------------------------------------------------*/
@@ -582,7 +584,9 @@ static int open_metadata(struct era_metadata *md)
 	md->metadata_snap = le64_to_cpu(disk->metadata_snap);
 	md->archived_writesets = true;
 
-	return dm_bm_unlock(sblock);
+	dm_bm_unlock(sblock);
+
+	return 0;
 
 bad:
 	dm_bm_unlock(sblock);
@@ -1046,12 +1050,7 @@ static int metadata_take_snap(struct era_metadata *md)
 
 	md->metadata_snap = dm_block_location(clone);
 
-	r = dm_tm_unlock(md->tm, clone);
-	if (r) {
-		DMERR("%s: couldn't unlock clone", __func__);
-		md->metadata_snap = SUPERBLOCK_LOCATION;
-		return r;
-	}
+	dm_tm_unlock(md->tm, clone);
 
 	return 0;
 }

drivers/md/dm-exception-store.c

@@ -183,7 +183,7 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
 
 	store->chunk_size = chunk_size;
 	store->chunk_mask = chunk_size - 1;
-	store->chunk_shift = ffs(chunk_size) - 1;
+	store->chunk_shift = __ffs(chunk_size);
 
 	return 0;
 }

drivers/md/dm-flakey.c

@@ -373,20 +373,20 @@ static void flakey_status(struct dm_target *ti, status_type_t type,
 	}
 }
 
-static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
+static int flakey_prepare_ioctl(struct dm_target *ti,
+		struct block_device **bdev, fmode_t *mode)
 {
 	struct flakey_c *fc = ti->private;
-	struct dm_dev *dev = fc->dev;
-	int r = 0;
+
+	*bdev = fc->dev->bdev;
 
 	/*
 	 * Only pass ioctls through if the device sizes match exactly.
 	 */
 	if (fc->start ||
-	    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
-		r = scsi_verify_blk_ioctl(NULL, cmd);
-
-	return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
+	    ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
+		return 1;
+	return 0;
 }
 
 static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
@@ -405,7 +405,7 @@ static struct target_type flakey_target = {
 	.map    = flakey_map,
 	.end_io = flakey_end_io,
 	.status = flakey_status,
-	.ioctl	= flakey_ioctl,
+	.prepare_ioctl = flakey_prepare_ioctl,
 	.iterate_devices = flakey_iterate_devices,
 };
 

drivers/md/dm-io.c

@@ -65,8 +65,7 @@ struct dm_io_client *dm_io_client_create(void)
 	return client;
 
    bad:
-	if (client->pool)
-		mempool_destroy(client->pool);
+	mempool_destroy(client->pool);
 	kfree(client);
 	return ERR_PTR(-ENOMEM);
 }

drivers/md/dm-linear.c

@@ -39,20 +39,20 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 	if (lc == NULL) {
-		ti->error = "dm-linear: Cannot allocate linear context";
+		ti->error = "Cannot allocate linear context";
 		return -ENOMEM;
 	}
 
 	ret = -EINVAL;
 	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
-		ti->error = "dm-linear: Invalid device sector";
+		ti->error = "Invalid device sector";
 		goto bad;
 	}
 	lc->start = tmp;
 
 	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
 	if (ret) {
-		ti->error = "dm-linear: Device lookup failed";
+		ti->error = "Device lookup failed";
 		goto bad;
 	}
 
@@ -116,21 +116,21 @@ static void linear_status(struct dm_target *ti, status_type_t type,
 	}
 }
 
-static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
-			unsigned long arg)
+static int linear_prepare_ioctl(struct dm_target *ti,
+		struct block_device **bdev, fmode_t *mode)
 {
 	struct linear_c *lc = (struct linear_c *) ti->private;
 	struct dm_dev *dev = lc->dev;
-	int r = 0;
+
+	*bdev = dev->bdev;
 
 	/*
 	 * Only pass ioctls through if the device sizes match exactly.
 	 */
 	if (lc->start ||
 	    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
-		r = scsi_verify_blk_ioctl(NULL, cmd);
-
-	return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
+		return 1;
+	return 0;
 }
 
 static int linear_iterate_devices(struct dm_target *ti,
@@ -149,7 +149,7 @@ static struct target_type linear_target = {
 	.dtr    = linear_dtr,
 	.map    = linear_map,
 	.status = linear_status,
-	.ioctl  = linear_ioctl,
+	.prepare_ioctl = linear_prepare_ioctl,
 	.iterate_devices = linear_iterate_devices,
 };
 

drivers/md/dm-log-userspace-base.c

@@ -313,8 +313,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 out:
 	kfree(devices_rdata);
 	if (r) {
-		if (lc->flush_entry_pool)
-			mempool_destroy(lc->flush_entry_pool);
+		mempool_destroy(lc->flush_entry_pool);
 		kfree(lc);
 		kfree(ctr_str);
 	} else {

drivers/md/dm-log-writes.c

@@ -714,20 +714,19 @@ static void log_writes_status(struct dm_target *ti, status_type_t type,
 	}
 }
 
-static int log_writes_ioctl(struct dm_target *ti, unsigned int cmd,
-			    unsigned long arg)
+static int log_writes_prepare_ioctl(struct dm_target *ti,
+		struct block_device **bdev, fmode_t *mode)
 {
 	struct log_writes_c *lc = ti->private;
 	struct dm_dev *dev = lc->dev;
-	int r = 0;
 
+	*bdev = dev->bdev;
 	/*
 	 * Only pass ioctls through if the device sizes match exactly.
 	 */
 	if (ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
-		r = scsi_verify_blk_ioctl(NULL, cmd);
-
-	return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
+		return 1;
+	return 0;
 }
 
 static int log_writes_iterate_devices(struct dm_target *ti,
@@ -782,7 +781,7 @@ static struct target_type log_writes_target = {
 	.map    = log_writes_map,
 	.end_io = normal_end_io,
 	.status = log_writes_status,
-	.ioctl	= log_writes_ioctl,
+	.prepare_ioctl = log_writes_prepare_ioctl,
 	.message = log_writes_message,
 	.iterate_devices = log_writes_iterate_devices,
 	.io_hints = log_writes_io_hints,