19 files changed, 345 insertions, 27 deletions

diff --git a/Documentation/admin-guide/device-mapper/verity.rst b/Documentation/admin-guide/device-mapper/verity.rst
index 8c50e5c96ee1..1a6b91368e59 100644
--- a/Documentation/admin-guide/device-mapper/verity.rst
+++ b/Documentation/admin-guide/device-mapper/verity.rst
@@ -134,7 +134,12 @@ root_hash_sig_key_desc <key_description>
     the pkcs7 signature of the roothash. The pkcs7 signature is used to validate
     the root hash during the creation of the device mapper block device.
     Verification of roothash depends on the config DM_VERITY_VERIFY_ROOTHASH_SIG
-    being set in the kernel.
+    being set in the kernel.  The signatures are checked against the builtin
+    trusted keyring by default, or the secondary trusted keyring if
+    DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING is set.  The secondary
+    trusted keyring includes by default the builtin trusted keyring, and it can
+    also gain new certificates at run time if they are signed by a certificate
+    already in the secondary trusted keyring.
 
 Theory of operation
 ===================
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 30ba3573626c..b7e2d9666614 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -463,6 +463,15 @@ config DM_MULTIPATH_HST
 
 	  If unsure, say N.
 
+config DM_MULTIPATH_IOA
+	tristate "I/O Path Selector based on CPU submission"
+	depends on DM_MULTIPATH
+	help
+	  This path selector selects the path based on the CPU the IO is
+	  executed on and the CPU to path mapping setup at path addition time.
+
+	  If unsure, say N.
+
 config DM_DELAY
 	tristate "I/O delaying target"
 	depends on BLK_DEV_DM
@@ -530,11 +539,22 @@ config DM_VERITY_VERIFY_ROOTHASH_SIG
 	bool "Verity data device root hash signature verification support"
 	depends on DM_VERITY
 	select SYSTEM_DATA_VERIFICATION
-	  help
+	help
 	  Add ability for dm-verity device to be validated if the
 	  pre-generated tree of cryptographic checksums passed has a pkcs#7
 	  signature file that can validate the roothash of the tree.
 
+	  By default, rely on the builtin trusted keyring.
+
+	  If unsure, say N.
+
+config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
+	bool "Verity data device root hash signature verification with secondary keyring"
+	depends on DM_VERITY_VERIFY_ROOTHASH_SIG
+	depends on SECONDARY_TRUSTED_KEYRING
+	help
+	  Rely on the secondary trusted keyring to verify dm-verity signatures.
+
 	  If unsure, say N.
 
 config DM_VERITY_FEC
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 6d3e234dc46a..ef7ddc27685c 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -7,23 +7,28 @@ dm-mod-y	+= dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
 		   dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-stats.o \
 		   dm-rq.o
 dm-multipath-y	+= dm-path-selector.o dm-mpath.o
+dm-historical-service-time-y += dm-ps-historical-service-time.o
+dm-io-affinity-y += dm-ps-io-affinity.o
+dm-queue-length-y += dm-ps-queue-length.o
+dm-round-robin-y += dm-ps-round-robin.o
+dm-service-time-y += dm-ps-service-time.o
 dm-snapshot-y	+= dm-snap.o dm-exception-store.o dm-snap-transient.o \
 		    dm-snap-persistent.o
 dm-mirror-y	+= dm-raid1.o
-dm-log-userspace-y \
-		+= dm-log-userspace-base.o dm-log-userspace-transfer.o
+dm-log-userspace-y += dm-log-userspace-base.o dm-log-userspace-transfer.o
 dm-bio-prison-y += dm-bio-prison-v1.o dm-bio-prison-v2.o
 dm-thin-pool-y	+= dm-thin.o dm-thin-metadata.o
 dm-cache-y	+= dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o \
 		    dm-cache-background-tracker.o
-dm-cache-smq-y   += dm-cache-policy-smq.o
+dm-cache-smq-y	+= dm-cache-policy-smq.o
 dm-ebs-y	+= dm-ebs-target.o
 dm-era-y	+= dm-era-target.o
 dm-clone-y	+= dm-clone-target.o dm-clone-metadata.o
 dm-verity-y	+= dm-verity-target.o
+dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
+
 md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
-dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 linear-y	+= md-linear.o
 multipath-y	+= md-multipath.o
 faulty-y	+= md-faulty.o
@@ -59,14 +64,15 @@ obj-$(CONFIG_DM_MULTIPATH)	+= dm-multipath.o dm-round-robin.o
 obj-$(CONFIG_DM_MULTIPATH_QL)	+= dm-queue-length.o
 obj-$(CONFIG_DM_MULTIPATH_ST)	+= dm-service-time.o
 obj-$(CONFIG_DM_MULTIPATH_HST)	+= dm-historical-service-time.o
+obj-$(CONFIG_DM_MULTIPATH_IOA)	+= dm-io-affinity.o
 obj-$(CONFIG_DM_SWITCH)		+= dm-switch.o
 obj-$(CONFIG_DM_SNAPSHOT)	+= dm-snapshot.o
-obj-$(CONFIG_DM_PERSISTENT_DATA)	+= persistent-data/
+obj-$(CONFIG_DM_PERSISTENT_DATA) += persistent-data/
 obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o dm-region-hash.o
 obj-$(CONFIG_DM_LOG_USERSPACE)	+= dm-log-userspace.o
 obj-$(CONFIG_DM_ZERO)		+= dm-zero.o
-obj-$(CONFIG_DM_RAID)	+= dm-raid.o
-obj-$(CONFIG_DM_THIN_PROVISIONING)	+= dm-thin-pool.o
+obj-$(CONFIG_DM_RAID)		+= dm-raid.o
+obj-$(CONFIG_DM_THIN_PROVISIONING) += dm-thin-pool.o
 obj-$(CONFIG_DM_VERITY)		+= dm-verity.o
 obj-$(CONFIG_DM_CACHE)		+= dm-cache.o
 obj-$(CONFIG_DM_CACHE_SMQ)	+= dm-cache-smq.o
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 4bc453f5bbaa..541c45027cc8 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -2840,7 +2840,6 @@ static void cache_postsuspend(struct dm_target *ti)
 static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
 			bool dirty, uint32_t hint, bool hint_valid)
 {
-	int r;
 	struct cache *cache = context;
 
 	if (dirty) {
@@ -2849,11 +2848,7 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
 	} else
 		clear_bit(from_cblock(cblock), cache->dirty_bitset);
 
-	r = policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid);
-	if (r)
-		return r;
-
-	return 0;
+	return policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid);
 }
 
 /*
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 392337f16ecf..5f9f9b3a226d 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1090,16 +1090,16 @@ static const struct crypt_iv_operations crypt_iv_tcw_ops = {
 	.post	   = crypt_iv_tcw_post
 };
 
-static struct crypt_iv_operations crypt_iv_random_ops = {
+static const struct crypt_iv_operations crypt_iv_random_ops = {
 	.generator = crypt_iv_random_gen
 };
 
-static struct crypt_iv_operations crypt_iv_eboiv_ops = {
+static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
 	.ctr	   = crypt_iv_eboiv_ctr,
 	.generator = crypt_iv_eboiv_gen
 };
 
-static struct crypt_iv_operations crypt_iv_elephant_ops = {
+static const struct crypt_iv_operations crypt_iv_elephant_ops = {
 	.ctr	   = crypt_iv_elephant_ctr,
 	.dtr	   = crypt_iv_elephant_dtr,
 	.init	   = crypt_iv_elephant_init,
@@ -3166,11 +3166,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 
 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
-		cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
+		cc->crypt_queue = alloc_workqueue("kcryptd-%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
 						  1, devname);
 	else
-		cc->crypt_queue = alloc_workqueue("kcryptd/%s",
-						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
+		cc->crypt_queue = alloc_workqueue("kcryptd-%s",
+						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM |
+						  WQ_UNBOUND | WQ_SYSFS,
 						  num_online_cpus(), devname);
 	if (!cc->crypt_queue) {
 		ti->error = "Couldn't create kcryptd queue";
diff --git a/drivers/md/dm-ebs-target.c b/drivers/md/dm-ebs-target.c
index cb85610527c2..55bcfb74f51f 100644
--- a/drivers/md/dm-ebs-target.c
+++ b/drivers/md/dm-ebs-target.c
@@ -86,7 +86,7 @@ static int __ebs_rw_bvec(struct ebs_c *ec, int rw, struct bio_vec *bv, struct bv
 		else
 			ba = dm_bufio_new(ec->bufio, block, &b);
 
-		if (unlikely(IS_ERR(ba))) {
+		if (IS_ERR(ba)) {
 			/*
 			 * Carry on with next buffer, if any, to issue all possible
 			 * data but return error.
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index cd0478d44058..5e306bba4375 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1600,6 +1600,7 @@ static int target_message(struct file *filp, struct dm_ioctl *param, size_t para
 
 	if (!argc) {
 		DMWARN("Empty message received.");
+		r = -EINVAL;
 		goto out_argv;
 	}
 
diff --git a/drivers/md/dm-historical-service-time.c b/drivers/md/dm-ps-historical-service-time.c
index 186f91e2752c..186f91e2752c 100644
--- a/drivers/md/dm-historical-service-time.c
+++ b/drivers/md/dm-ps-historical-service-time.c
diff --git a/drivers/md/dm-ps-io-affinity.c b/drivers/md/dm-ps-io-affinity.c
new file mode 100644
index 000000000000..077655cd4fae
--- /dev/null
+++ b/drivers/md/dm-ps-io-affinity.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Oracle Corporation
+ *
+ * Module Author: Mike Christie
+ */
+#include "dm-path-selector.h"
+
+#include <linux/device-mapper.h>
+#include <linux/module.h>
+
+#define DM_MSG_PREFIX "multipath io-affinity"
+
+struct path_info {
+	struct dm_path *path;
+	cpumask_var_t cpumask;
+	refcount_t refcount;
+	bool failed;
+};
+
+struct selector {
+	struct path_info **path_map;
+	cpumask_var_t path_mask;
+	atomic_t map_misses;
+};
+
+static void ioa_free_path(struct selector *s, unsigned int cpu)
+{
+	struct path_info *pi = s->path_map[cpu];
+
+	if (!pi)
+		return;
+
+	if (refcount_dec_and_test(&pi->refcount)) {
+		cpumask_clear_cpu(cpu, s->path_mask);
+		free_cpumask_var(pi->cpumask);
+		kfree(pi);
+
+		s->path_map[cpu] = NULL;
+	}
+}
+
+static int ioa_add_path(struct path_selector *ps, struct dm_path *path,
+			int argc, char **argv, char **error)
+{
+	struct selector *s = ps->context;
+	struct path_info *pi = NULL;
+	unsigned int cpu;
+	int ret;
+
+	if (argc != 1) {
+		*error = "io-affinity ps: invalid number of arguments";
+		return -EINVAL;
+	}
+
+	pi = kzalloc(sizeof(*pi), GFP_KERNEL);
+	if (!pi) {
+		*error = "io-affinity ps: Error allocating path context";
+		return -ENOMEM;
+	}
+
+	pi->path = path;
+	path->pscontext = pi;
+	refcount_set(&pi->refcount, 1);
+
+	if (!zalloc_cpumask_var(&pi->cpumask, GFP_KERNEL)) {
+		*error = "io-affinity ps: Error allocating cpumask context";
+		ret = -ENOMEM;
+		goto free_pi;
+	}
+
+	ret = cpumask_parse(argv[0], pi->cpumask);
+	if (ret) {
+		*error = "io-affinity ps: invalid cpumask";
+		ret = -EINVAL;
+		goto free_mask;
+	}
+
+	for_each_cpu(cpu, pi->cpumask) {
+		if (cpu >= nr_cpu_ids) {
+			DMWARN_LIMIT("Ignoring mapping for CPU %u. Max CPU is %u",
+				     cpu, nr_cpu_ids);
+			break;
+		}
+
+		if (s->path_map[cpu]) {
+			DMWARN("CPU mapping for %u exists. Ignoring.", cpu);
+			continue;
+		}
+
+		cpumask_set_cpu(cpu, s->path_mask);
+		s->path_map[cpu] = pi;
+		refcount_inc(&pi->refcount);
+		continue;
+	}
+
+	if (refcount_dec_and_test(&pi->refcount)) {
+		*error = "io-affinity ps: No new/valid CPU mapping found";
+		ret = -EINVAL;
+		goto free_mask;
+	}
+
+	return 0;
+
+free_mask:
+	free_cpumask_var(pi->cpumask);
+free_pi:
+	kfree(pi);
+	return ret;
+}
+
+static int ioa_create(struct path_selector *ps, unsigned argc, char **argv)
+{
+	struct selector *s;
+
+	s = kmalloc(sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	s->path_map = kzalloc(nr_cpu_ids * sizeof(struct path_info *),
+			      GFP_KERNEL);
+	if (!s->path_map)
+		goto free_selector;
+
+	if (!zalloc_cpumask_var(&s->path_mask, GFP_KERNEL))
+		goto free_map;
+
+	atomic_set(&s->map_misses, 0);
+	ps->context = s;
+	return 0;
+
+free_map:
+	kfree(s->path_map);
+free_selector:
+	kfree(s);
+	return -ENOMEM;
+}
+
+static void ioa_destroy(struct path_selector *ps)
+{
+	struct selector *s = ps->context;
+	unsigned cpu;
+
+	for_each_cpu(cpu, s->path_mask)
+		ioa_free_path(s, cpu);
+
+	free_cpumask_var(s->path_mask);
+	kfree(s->path_map);
+	kfree(s);
+
+	ps->context = NULL;
+}
+
+static int ioa_status(struct path_selector *ps, struct dm_path *path,
+		      status_type_t type, char *result, unsigned int maxlen)
+{
+	struct selector *s = ps->context;
+	struct path_info *pi;
+	int sz = 0;
+
+	if (!path) {
+		DMEMIT("0 ");
+		return sz;
+	}
+
+	switch(type) {
+	case STATUSTYPE_INFO:
+		DMEMIT("%d ", atomic_read(&s->map_misses));
+		break;
+	case STATUSTYPE_TABLE:
+		pi = path->pscontext;
+		DMEMIT("%*pb ", cpumask_pr_args(pi->cpumask));
+		break;
+	}
+
+	return sz;
+}
+
+static void ioa_fail_path(struct path_selector *ps, struct dm_path *p)
+{
+	struct path_info *pi = p->pscontext;
+
+	pi->failed = true;
+}
+
+static int ioa_reinstate_path(struct path_selector *ps, struct dm_path *p)
+{
+	struct path_info *pi = p->pscontext;
+
+	pi->failed = false;
+	return 0;
+}
+
+static struct dm_path *ioa_select_path(struct path_selector *ps,
+				       size_t nr_bytes)
+{
+	unsigned int cpu, node;
+	struct selector *s = ps->context;
+	const struct cpumask *cpumask;
+	struct path_info *pi;
+	int i;
+
+	cpu = get_cpu();
+
+	pi = s->path_map[cpu];
+	if (pi && !pi->failed)
+		goto done;
+
+	/*
+	 * Perf is not optimal, but we at least try the local node then just
+	 * try not to fail.
+	 */
+	if (!pi)
+		atomic_inc(&s->map_misses);
+
+	node = cpu_to_node(cpu);
+	cpumask = cpumask_of_node(node);
+	for_each_cpu(i, cpumask) {
+		pi = s->path_map[i];
+		if (pi && !pi->failed)
+			goto done;
+	}
+
+	for_each_cpu(i, s->path_mask) {
+		pi = s->path_map[i];
+		if (pi && !pi->failed)
+			goto done;
+	}
+	pi = NULL;
+
+done:
+	put_cpu();
+	return pi ? pi->path : NULL;
+}
+
+static struct path_selector_type ioa_ps = {
+	.name		= "io-affinity",
+	.module		= THIS_MODULE,
+	.table_args	= 1,
+	.info_args	= 1,
+	.create		= ioa_create,
+	.destroy	= ioa_destroy,
+	.status		= ioa_status,
+	.add_path	= ioa_add_path,
+	.fail_path	= ioa_fail_path,
+	.reinstate_path	= ioa_reinstate_path,
+	.select_path	= ioa_select_path,
+};
+
+static int __init dm_ioa_init(void)
+{
+	int ret = dm_register_path_selector(&ioa_ps);
+
+	if (ret < 0)
+		DMERR("register failed %d", ret);
+	return ret;
+}
+
+static void __exit dm_ioa_exit(void)
+{
+	int ret = dm_unregister_path_selector(&ioa_ps);
+
+	if (ret < 0)
+		DMERR("unregister failed %d", ret);
+}
+
+module_init(dm_ioa_init);
+module_exit(dm_ioa_exit);
+
+MODULE_DESCRIPTION(DM_NAME " multipath path selector that selects paths based on the CPU IO is being executed on");
+MODULE_AUTHOR("Mike Christie <michael.christie@oracle.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/md/dm-queue-length.c b/drivers/md/dm-ps-queue-length.c
index 5fd018d18418..5fd018d18418 100644
--- a/drivers/md/dm-queue-length.c
+++ b/drivers/md/dm-ps-queue-length.c
diff --git a/drivers/md/dm-round-robin.c b/drivers/md/dm-ps-round-robin.c
index bdbb7e6e8212..bdbb7e6e8212 100644
--- a/drivers/md/dm-round-robin.c
+++ b/drivers/md/dm-ps-round-robin.c
diff --git a/drivers/md/dm-service-time.c b/drivers/md/dm-ps-service-time.c
index 9cfda665e9eb..9cfda665e9eb 100644
--- a/drivers/md/dm-service-time.c
+++ b/drivers/md/dm-ps-service-time.c
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 151d022b032d..df359d33cda8 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -496,7 +496,7 @@ static void stripe_io_hints(struct dm_target *ti,
 static struct target_type stripe_target = {
 	.name   = "striped",
 	.version = {1, 6, 0},
-	.features = DM_TARGET_PASSES_INTEGRITY,
+	.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT,
 	.module = THIS_MODULE,
 	.ctr    = stripe_ctr,
 	.dtr    = stripe_dtr,
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index bff4c7fa1cd2..262e2b0fd975 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -550,6 +550,7 @@ static int switch_iterate_devices(struct dm_target *ti,
 static struct target_type switch_target = {
 	.name = "switch",
 	.version = {1, 1, 0},
+	.features = DM_TARGET_NOWAIT,
 	.module = THIS_MODULE,
 	.ctr = switch_ctr,
 	.dtr = switch_dtr,
diff --git a/drivers/md/dm-unstripe.c b/drivers/md/dm-unstripe.c
index e673dacf6418..7357c1bd5863 100644
--- a/drivers/md/dm-unstripe.c
+++ b/drivers/md/dm-unstripe.c
@@ -178,6 +178,7 @@ static void unstripe_io_hints(struct dm_target *ti,
 static struct target_type unstripe_target = {
 	.name = "unstriped",
 	.version = {1, 1, 0},
+	.features = DM_TARGET_NOWAIT,
 	.module = THIS_MODULE,
 	.ctr = unstripe_ctr,
 	.dtr = unstripe_dtr,
diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index f74982dcbea0..6b8e5bdd8526 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -538,6 +538,15 @@ static int verity_verify_io(struct dm_verity_io *io)
 }
 
 /*
+ * Skip verity work in response to I/O error when system is shutting down.
+ */
+static inline bool verity_is_system_shutting_down(void)
+{
+	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
+		|| system_state == SYSTEM_RESTART;
+}
+
+/*
  * End one "io" structure with a given error.
  */
 static void verity_finish_io(struct dm_verity_io *io, blk_status_t status)
@@ -564,7 +573,8 @@ static void verity_end_io(struct bio *bio)
 {
 	struct dm_verity_io *io = bio->bi_private;
 
-	if (bio->bi_status && !verity_fec_is_enabled(io->v)) {
+	if (bio->bi_status &&
+	    (!verity_fec_is_enabled(io->v) || verity_is_system_shutting_down())) {
 		verity_finish_io(io, bio->bi_status);
 		return;
 	}
diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c
index 614e43db93aa..29385dc470d5 100644
--- a/drivers/md/dm-verity-verify-sig.c
+++ b/drivers/md/dm-verity-verify-sig.c
@@ -119,8 +119,13 @@ int verity_verify_root_hash(const void *root_hash, size_t root_hash_len,
 	}
 
 	ret = verify_pkcs7_signature(root_hash, root_hash_len, sig_data,
-				sig_len, NULL, VERIFYING_UNSPECIFIED_SIGNATURE,
-				NULL, NULL);
+				sig_len,
+#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
+				VERIFY_USE_SECONDARY_KEYRING,
+#else
+				NULL,
+#endif
+				VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL);
 
 	return ret;
 }
diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c
index b65ca8dcfbdc..faa1dbffc8b4 100644
--- a/drivers/md/dm-zero.c
+++ b/drivers/md/dm-zero.c
@@ -59,6 +59,7 @@ static int zero_map(struct dm_target *ti, struct bio *bio)
 static struct target_type zero_target = {
 	.name   = "zero",
 	.version = {1, 1, 0},
+	.features = DM_TARGET_NOWAIT,
 	.module = THIS_MODULE,
 	.ctr    = zero_ctr,
 	.map    = zero_map,
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 5b2f371ec4bb..b3c3c8b4cb42 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1586,7 +1586,7 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
 		ci.sector_count = bio_sectors(bio);
 		while (ci.sector_count && !error) {
 			error = __split_and_process_non_flush(&ci);
-			if (current->bio_list && ci.sector_count && !error) {
+			if (ci.sector_count && !error) {
 				/*
 				 * Remainder must be passed to submit_bio_noacct()
 				 * so that it gets handled *after* bios already submitted