Merge tag 'for-5.1/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Two queue_limits stacking fixes: disable discards if underlying
   driver does. And propagate BDI_CAP_STABLE_WRITES to fix sporadic
   checksum errors.

 - Fix that reverts a DM core limit that wasn't needed given that
   dm-crypt was already updated to impose an equivalent limit.

 - Fix dm-init to properly establish 'const' for __initconst array.

 - Fix deadlock in DM integrity target that occurs when overlapping IO
   is being issued to it. And two smaller fixes to the DM integrity
   target.

* tag 'for-5.1/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm integrity: fix deadlock with overlapping I/O
  dm: disable DISCARD if the underlying storage no longer supports it
  dm table: propagate BDI_CAP_STABLE_WRITES to fix sporadic checksum errors
  dm: revert 8f50e358153d ("dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE")
  dm init: fix const confusion for dm_allowed_targets array
  dm integrity: make dm_integrity_init and dm_integrity_exit static
  dm integrity: change memcmp to strncmp in dm_integrity_ctr

6 files changed, 72 insertions, 27 deletions

diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index 95c6d86ab5e8..c4ef1fceead6 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -115,6 +115,7 @@ struct mapped_device {
 	struct srcu_struct io_barrier;
 };
 
+void disable_discard(struct mapped_device *md);
 void disable_write_same(struct mapped_device *md);
 void disable_write_zeroes(struct mapped_device *md);
 
diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
index b53f30f16b4d..4b76f84424c3 100644
--- a/drivers/md/dm-init.c
+++ b/drivers/md/dm-init.c
@@ -36,7 +36,7 @@ struct dm_device {
 	struct list_head list;
 };
 
-const char *dm_allowed_targets[] __initconst = {
+const char * const dm_allowed_targets[] __initconst = {
 	"crypt",
 	"delay",
 	"linear",
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index d57d997a52c8..7c678f50aaa3 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -913,7 +913,7 @@ static void copy_from_journal(struct dm_integrity_c *ic, unsigned section, unsig
 static bool ranges_overlap(struct dm_integrity_range *range1, struct dm_integrity_range *range2)
 {
 	return range1->logical_sector < range2->logical_sector + range2->n_sectors &&
-	       range2->logical_sector + range2->n_sectors > range2->logical_sector;
+	       range1->logical_sector + range1->n_sectors > range2->logical_sector;
 }
 
 static bool add_new_range(struct dm_integrity_c *ic, struct dm_integrity_range *new_range, bool check_waiting)
@@ -959,8 +959,6 @@ static void remove_range_unlocked(struct dm_integrity_c *ic, struct dm_integrity
 		struct dm_integrity_range *last_range =
 			list_first_entry(&ic->wait_list, struct dm_integrity_range, wait_entry);
 		struct task_struct *last_range_task;
-		if (!ranges_overlap(range, last_range))
-			break;
 		last_range_task = last_range->task;
 		list_del(&last_range->wait_entry);
 		if (!add_new_range(ic, last_range, false)) {
@@ -3185,7 +3183,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 			journal_watermark = val;
 		else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1)
 			sync_msec = val;
-		else if (!memcmp(opt_string, "meta_device:", strlen("meta_device:"))) {
+		else if (!strncmp(opt_string, "meta_device:", strlen("meta_device:"))) {
 			if (ic->meta_dev) {
 				dm_put_device(ti, ic->meta_dev);
 				ic->meta_dev = NULL;
@@ -3204,17 +3202,17 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 				goto bad;
 			}
 			ic->sectors_per_block = val >> SECTOR_SHIFT;
-		} else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
+		} else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
 			r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
 					    "Invalid internal_hash argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
+		} else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
 					    "Invalid journal_crypt argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
+		} else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
 					    "Invalid journal_mac argument");
 			if (r)
@@ -3616,7 +3614,7 @@ static struct target_type integrity_target = {
 	.io_hints		= dm_integrity_io_hints,
 };
 
-int __init dm_integrity_init(void)
+static int __init dm_integrity_init(void)
 {
 	int r;
 
@@ -3635,7 +3633,7 @@ int __init dm_integrity_init(void)
 	return r;
 }
 
-void dm_integrity_exit(void)
+static void __exit dm_integrity_exit(void)
 {
 	dm_unregister_target(&integrity_target);
 	kmem_cache_destroy(journal_io_cache);
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 09773636602d..b66745bd08bb 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -222,11 +222,14 @@ static void dm_done(struct request *clone, blk_status_t error, bool mapped)
 	}
 
 	if (unlikely(error == BLK_STS_TARGET)) {
-		if (req_op(clone) == REQ_OP_WRITE_SAME &&
-		    !clone->q->limits.max_write_same_sectors)
+		if (req_op(clone) == REQ_OP_DISCARD &&
+		    !clone->q->limits.max_discard_sectors)
+			disable_discard(tio->md);
+		else if (req_op(clone) == REQ_OP_WRITE_SAME &&
+			 !clone->q->limits.max_write_same_sectors)
 			disable_write_same(tio->md);
-		if (req_op(clone) == REQ_OP_WRITE_ZEROES &&
-		    !clone->q->limits.max_write_zeroes_sectors)
+		else if (req_op(clone) == REQ_OP_WRITE_ZEROES &&
+			 !clone->q->limits.max_write_zeroes_sectors)
 			disable_write_zeroes(tio->md);
 	}
 
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index ba9481f1bf3c..cde3b49b2a91 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1844,6 +1844,36 @@ static bool dm_table_supports_secure_erase(struct dm_table *t)
 	return true;
 }
 
+static int device_requires_stable_pages(struct dm_target *ti,
+					struct dm_dev *dev, sector_t start,
+					sector_t len, void *data)
+{
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && bdi_cap_stable_pages_required(q->backing_dev_info);
+}
+
+/*
+ * If any underlying device requires stable pages, a table must require
+ * them as well.  Only targets that support iterate_devices are considered:
+ * don't want error, zero, etc to require stable pages.
+ */
+static bool dm_table_requires_stable_pages(struct dm_table *t)
+{
+	struct dm_target *ti;
+	unsigned i;
+
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
+			return true;
+	}
+
+	return false;
+}
+
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 			       struct queue_limits *limits)
 {
@@ -1897,6 +1927,15 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	dm_table_verify_integrity(t);
 
 	/*
+	 * Some devices don't use blk_integrity but still want stable pages
+	 * because they do their own checksumming.
+	 */
+	if (dm_table_requires_stable_pages(t))
+		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
+	else
+		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
+
+	/*
 	 * Determine whether or not this queue's I/O timings contribute
 	 * to the entropy pool, Only request-based targets use this.
 	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 68d24056d0b1..043f0761e4a0 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -945,6 +945,15 @@ static void dec_pending(struct dm_io *io, blk_status_t error)
 	}
 }
 
+void disable_discard(struct mapped_device *md)
+{
+	struct queue_limits *limits = dm_get_queue_limits(md);
+
+	/* device doesn't really support DISCARD, disable it */
+	limits->max_discard_sectors = 0;
+	blk_queue_flag_clear(QUEUE_FLAG_DISCARD, md->queue);
+}
+
 void disable_write_same(struct mapped_device *md)
 {
 	struct queue_limits *limits = dm_get_queue_limits(md);
@@ -970,11 +979,14 @@ static void clone_endio(struct bio *bio)
 	dm_endio_fn endio = tio->ti->type->end_io;
 
 	if (unlikely(error == BLK_STS_TARGET) && md->type != DM_TYPE_NVME_BIO_BASED) {
-		if (bio_op(bio) == REQ_OP_WRITE_SAME &&
-		    !bio->bi_disk->queue->limits.max_write_same_sectors)
+		if (bio_op(bio) == REQ_OP_DISCARD &&
+		    !bio->bi_disk->queue->limits.max_discard_sectors)
+			disable_discard(md);
+		else if (bio_op(bio) == REQ_OP_WRITE_SAME &&
+			 !bio->bi_disk->queue->limits.max_write_same_sectors)
 			disable_write_same(md);
-		if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
-		    !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
+		else if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
+			 !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
 			disable_write_zeroes(md);
 	}
 
@@ -1042,15 +1054,7 @@ int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
 		return -EINVAL;
 	}
 
-	/*
-	 * BIO based queue uses its own splitting. When multipage bvecs
-	 * is switched on, size of the incoming bio may be too big to
-	 * be handled in some targets, such as crypt.
-	 *
-	 * When these targets are ready for the big bio, we can remove
-	 * the limit.
-	 */
-	ti->max_io_len = min_t(uint32_t, len, BIO_MAX_PAGES * PAGE_SIZE);
+	ti->max_io_len = (uint32_t) len;
 
 	return 0;
 }