9 files changed, 83 insertions, 8 deletions

diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index 136fda3ff9e5..fea5bd52ada8 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -132,6 +132,7 @@ void dm_init_md_queue(struct mapped_device *md);
 void dm_init_normal_md_queue(struct mapped_device *md);
 int md_in_flight(struct mapped_device *md);
 void disable_write_same(struct mapped_device *md);
+void disable_write_zeroes(struct mapped_device *md);
 
 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
 {
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index b808cbe22678..3702e502466d 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -312,9 +312,12 @@ static void do_region(int op, int op_flags, unsigned region,
          */
         if (op == REQ_OP_DISCARD)
                 special_cmd_max_sectors = q->limits.max_discard_sectors;
+        else if (op == REQ_OP_WRITE_ZEROES)
+                special_cmd_max_sectors = q->limits.max_write_zeroes_sectors;
         else if (op == REQ_OP_WRITE_SAME)
                 special_cmd_max_sectors = q->limits.max_write_same_sectors;
-        if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_SAME) &&
+        if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES ||
+             op == REQ_OP_WRITE_SAME)  &&
             special_cmd_max_sectors == 0) {
                 dec_count(io, region, -EOPNOTSUPP);
                 return;
@@ -330,6 +333,7 @@ static void do_region(int op, int op_flags, unsigned region,
                  */
                 switch (op) {
                 case REQ_OP_DISCARD:
+                case REQ_OP_WRITE_ZEROES:
                         num_bvecs = 0;
                         break;
                 case REQ_OP_WRITE_SAME:
@@ -347,7 +351,7 @@ static void do_region(int op, int op_flags, unsigned region,
                 bio_set_op_attrs(bio, op, op_flags);
                 store_io_and_region_in_bio(bio, io, region);
 
-                if (op == REQ_OP_DISCARD) {
+                if (op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) {
                         num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
                         bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
                         remaining -= num_sectors;
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 4788b0b989a9..e17fd44ceef5 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -59,6 +59,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         ti->num_flush_bios = 1;
         ti->num_discard_bios = 1;
         ti->num_write_same_bios = 1;
+        ti->num_write_zeroes_bios = 1;
         ti->private = lc;
         return 0;
 
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 7f223dbed49f..ab55955ed704 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1103,6 +1103,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv)
         ti->num_flush_bios = 1;
         ti->num_discard_bios = 1;
         ti->num_write_same_bios = 1;
+        ti->num_write_zeroes_bios = 1;
         if (m->queue_mode == DM_TYPE_BIO_BASED)
                 ti->per_io_data_size = multipath_per_bio_data_size();
         else
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index d19af1d21f4c..e60f1b6845be 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -298,9 +298,14 @@ static void dm_done(struct request *clone, int error, bool mapped)
                         r = rq_end_io(tio->ti, clone, error, &tio->info);
         }
 
-        if (unlikely(r == -EREMOTEIO && (req_op(clone) == REQ_OP_WRITE_SAME) &&
-                     !clone->q->limits.max_write_same_sectors))
-                disable_write_same(tio->md);
+        if (unlikely(r == -EREMOTEIO)) {
+                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)
+                        disable_write_zeroes(tio->md);
+        }
 
         if (r <= 0)
                 /* The target wants to complete the I/O */
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 28193a57bf47..5ef49c121d99 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -169,6 +169,7 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         ti->num_flush_bios = stripes;
         ti->num_discard_bios = stripes;
         ti->num_write_same_bios = stripes;
+        ti->num_write_zeroes_bios = stripes;
 
         sc->chunk_size = chunk_size;
         if (chunk_size & (chunk_size - 1))
@@ -293,6 +294,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio)
                 return DM_MAPIO_REMAPPED;
         }
         if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
+            unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES) ||
             unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) {
                 target_bio_nr = dm_bio_get_target_bio_nr(bio);
                 BUG_ON(target_bio_nr >= sc->stripes);
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 3ad16d9c9d5a..5cd665c91ead 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1533,6 +1533,34 @@ static bool dm_table_supports_write_same(struct dm_table *t)
         return true;
 }
 
+static int device_not_write_zeroes_capable(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 && !q->limits.max_write_zeroes_sectors;
+}
+
+static bool dm_table_supports_write_zeroes(struct dm_table *t)
+{
+        struct dm_target *ti;
+        unsigned i = 0;
+
+        while (i < dm_table_get_num_targets(t)) {
+                ti = dm_table_get_target(t, i++);
+
+                if (!ti->num_write_zeroes_bios)
+                        return false;
+
+                if (!ti->type->iterate_devices ||
+                    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
+                        return false;
+        }
+
+        return true;
+}
+
+
 static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
                                   sector_t start, sector_t len, void *data)
 {
@@ -1603,6 +1631,8 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 
         if (!dm_table_supports_write_same(t))
                 q->limits.max_write_same_sectors = 0;
+        if (!dm_table_supports_write_zeroes(t))
+                q->limits.max_write_zeroes_sectors = 0;
 
         if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
                 queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index cd93a3b9ceca..8bf397729bbd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -824,6 +824,14 @@ void disable_write_same(struct mapped_device *md)
         limits->max_write_same_sectors = 0;
 }
 
+void disable_write_zeroes(struct mapped_device *md)
+{
+        struct queue_limits *limits = dm_get_queue_limits(md);
+
+        /* device doesn't really support WRITE ZEROES, disable it */
+        limits->max_write_zeroes_sectors = 0;
+}
+
 static void clone_endio(struct bio *bio)
 {
         int error = bio->bi_error;
@@ -850,9 +858,14 @@ static void clone_endio(struct bio *bio)
                 }
         }
 
-        if (unlikely(r == -EREMOTEIO && (bio_op(bio) == REQ_OP_WRITE_SAME) &&
-                     !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors))
-                disable_write_same(md);
+        if (unlikely(r == -EREMOTEIO)) {
+                if (bio_op(bio) == REQ_OP_WRITE_SAME &&
+                    !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)
+                        disable_write_same(md);
+                if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
+                    !bdev_get_queue(bio->bi_bdev)->limits.max_write_zeroes_sectors)
+                        disable_write_zeroes(md);
+        }
 
         free_tio(tio);
         dec_pending(io, error);
@@ -1201,6 +1214,11 @@ static unsigned get_num_write_same_bios(struct dm_target *ti)
         return ti->num_write_same_bios;
 }
 
+static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
+{
+        return ti->num_write_zeroes_bios;
+}
+
 typedef bool (*is_split_required_fn)(struct dm_target *ti);
 
 static bool is_split_required_for_discard(struct dm_target *ti)
@@ -1255,6 +1273,11 @@ static int __send_write_same(struct clone_info *ci)
         return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
 }
 
+static int __send_write_zeroes(struct clone_info *ci)
+{
+        return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);
+}
+
 /*
  * Select the correct strategy for processing a non-flush bio.
  */
@@ -1269,6 +1292,8 @@ static int __split_and_process_non_flush(struct clone_info *ci)
                 return __send_discard(ci);
         else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
                 return __send_write_same(ci);
+        else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))
+                return __send_write_zeroes(ci);
 
         ti = dm_table_find_target(ci->map, ci->sector);
         if (!dm_target_is_valid(ti))
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index a7e6903866fd..3829bee2302a 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -255,6 +255,12 @@ struct dm_target {
         unsigned num_write_same_bios;
 
         /*
+         * The number of WRITE ZEROES bios that will be submitted to the target.
+         * The bio number can be accessed with dm_bio_get_target_bio_nr.
+         */
+        unsigned num_write_zeroes_bios;
+
+        /*
          * The minimum number of extra bytes allocated in each io for the
          * target to use.
          */