Merge tag 'for-5.0/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix DM crypt's parsing of extended IV arguments.

 - Fix DM thinp's discard passdown to properly account for extra
   reference that is taken to guard against reallocating a block before
   a discard has been issued.

 - Fix bio-based DM's redundant IO accounting that was occurring for
   bios that must be split due to the nature of the DM target (e.g.
   dm-stripe, dm-thinp, etc).

* tag 'for-5.0/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: add missing trace_block_split() to __split_and_process_bio()
  dm: fix dm_wq_work() to only use __split_and_process_bio() if appropriate
  dm: fix redundant IO accounting for bios that need splitting
  dm: fix clone_bio() to trigger blk_recount_segments()
  dm thin: fix passdown_double_checking_shared_status()
  dm crypt: fix parsing of extended IV arguments

5 files changed, 56 insertions, 28 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 0ff22159a0ca..47d4e0d30bf0 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2414,9 +2414,21 @@ static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key
 	 * capi:cipher_api_spec-iv:ivopts
 	 */
 	tmp = &cipher_in[strlen("capi:")];
-	cipher_api = strsep(&tmp, "-");
-	*ivmode = strsep(&tmp, ":");
-	*ivopts = tmp;
+
+	/* Separate IV options if present, it can contain another '-' in hash name */
+	*ivopts = strrchr(tmp, ':');
+	if (*ivopts) {
+		**ivopts = '\0';
+		(*ivopts)++;
+	}
+	/* Parse IV mode */
+	*ivmode = strrchr(tmp, '-');
+	if (*ivmode) {
+		**ivmode = '\0';
+		(*ivmode)++;
+	}
+	/* The rest is crypto API spec */
+	cipher_api = tmp;
 
 	if (*ivmode && !strcmp(*ivmode, "lmk"))
 		cc->tfms_count = 64;
@@ -2486,11 +2498,8 @@ static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key
 		goto bad_mem;
 
 	chainmode = strsep(&tmp, "-");
-	*ivopts = strsep(&tmp, "-");
-	*ivmode = strsep(&*ivopts, ":");
-
-	if (tmp)
-		DMWARN("Ignoring unexpected additional cipher options");
+	*ivmode = strsep(&tmp, ":");
+	*ivopts = tmp;
 
 	/*
 	 * For compatibility with the original dm-crypt mapping format, if
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 20b0776e39ef..ed3caceaed07 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -1678,7 +1678,7 @@ int dm_thin_remove_range(struct dm_thin_device *td,
 	return r;
 }
 
-int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
+int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
 {
 	int r;
 	uint32_t ref_count;
@@ -1686,7 +1686,7 @@ int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *resu
 	down_read(&pmd->root_lock);
 	r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
 	if (!r)
-		*result = (ref_count != 0);
+		*result = (ref_count > 1);
 	up_read(&pmd->root_lock);
 
 	return r;
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index 35e954ea20a9..f6be0d733c20 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -195,7 +195,7 @@ int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
 
 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
 
-int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result);
+int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result);
 
 int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e);
 int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e);
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index dadd9696340c..ca8af21bf644 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -1048,7 +1048,7 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m
 	 * passdown we have to check that these blocks are now unused.
 	 */
 	int r = 0;
-	bool used = true;
+	bool shared = true;
 	struct thin_c *tc = m->tc;
 	struct pool *pool = tc->pool;
 	dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin;
@@ -1058,11 +1058,11 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m
 	while (b != end) {
 		/* find start of unmapped run */
 		for (; b < end; b++) {
-			r = dm_pool_block_is_used(pool->pmd, b, &used);
+			r = dm_pool_block_is_shared(pool->pmd, b, &shared);
 			if (r)
 				goto out;
 
-			if (!used)
+			if (!shared)
 				break;
 		}
 
@@ -1071,11 +1071,11 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m
 
 		/* find end of run */
 		for (e = b + 1; e != end; e++) {
-			r = dm_pool_block_is_used(pool->pmd, e, &used);
+			r = dm_pool_block_is_shared(pool->pmd, e, &shared);
 			if (r)
 				goto out;
 
-			if (used)
+			if (shared)
 				break;
 		}
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index d67c95ef8d7e..2b53c3841b53 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1320,7 +1320,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 
 	__bio_clone_fast(clone, bio);
 
-	if (unlikely(bio_integrity(bio) != NULL)) {
+	if (bio_integrity(bio)) {
 		int r;
 
 		if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
@@ -1336,11 +1336,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 			return r;
 	}
 
-	bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
-	clone->bi_iter.bi_size = to_bytes(len);
-
-	if (unlikely(bio_integrity(bio) != NULL))
-		bio_integrity_trim(clone);
+	bio_trim(clone, sector - clone->bi_iter.bi_sector, len);
 
 	return 0;
 }
@@ -1588,6 +1584,9 @@ static void init_clone_info(struct clone_info *ci, struct mapped_device *md,
 	ci->sector = bio->bi_iter.bi_sector;
 }
 
+#define __dm_part_stat_sub(part, field, subnd)	\
+	(part_stat_get(part, field) -= (subnd))
+
 /*
  * Entry point to split a bio into clones and submit them to the targets.
  */
@@ -1642,7 +1641,21 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
 				struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,
 							  GFP_NOIO, &md->queue->bio_split);
 				ci.io->orig_bio = b;
+
+				/*
+				 * Adjust IO stats for each split, otherwise upon queue
+				 * reentry there will be redundant IO accounting.
+				 * NOTE: this is a stop-gap fix, a proper fix involves
+				 * significant refactoring of DM core's bio splitting
+				 * (by eliminating DM's splitting and just using bio_split)
+				 */
+				part_stat_lock();
+				__dm_part_stat_sub(&dm_disk(md)->part0,
+						   sectors[op_stat_group(bio_op(bio))], ci.sector_count);
+				part_stat_unlock();
+
 				bio_chain(b, bio);
+				trace_block_split(md->queue, b, bio->bi_iter.bi_sector);
 				ret = generic_make_request(bio);
 				break;
 			}
@@ -1713,6 +1726,15 @@ out:
 	return ret;
 }
 
+static blk_qc_t dm_process_bio(struct mapped_device *md,
+			       struct dm_table *map, struct bio *bio)
+{
+	if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
+		return __process_bio(md, map, bio);
+	else
+		return __split_and_process_bio(md, map, bio);
+}
+
 static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct mapped_device *md = q->queuedata;
@@ -1733,10 +1755,7 @@ static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
 		return ret;
 	}
 
-	if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
-		ret = __process_bio(md, map, bio);
-	else
-		ret = __split_and_process_bio(md, map, bio);
+	ret = dm_process_bio(md, map, bio);
 
 	dm_put_live_table(md, srcu_idx);
 	return ret;
@@ -2415,9 +2434,9 @@ static void dm_wq_work(struct work_struct *work)
 			break;
 
 		if (dm_request_based(md))
-			generic_make_request(c);
+			(void) generic_make_request(c);
 		else
-			__split_and_process_bio(md, map, c);
+			(void) dm_process_bio(md, map, c);
 	}
 
 	dm_put_live_table(md, srcu_idx);