[Drbd-dev] [PATCH 07/25] dm: support REQ_OP_WRITE_ZEROES
Christoph Hellwig
hch at lst.de
Fri Mar 31 18:32:55 CEST 2017
Copy & paste from the REQ_OP_WRITE_SAME code.
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
drivers/md/dm-core.h | 1 +
drivers/md/dm-io.c | 8 ++++++--
drivers/md/dm-linear.c | 1 +
drivers/md/dm-mpath.c | 1 +
drivers/md/dm-rq.c | 11 ++++++++---
drivers/md/dm-stripe.c | 2 ++
drivers/md/dm-table.c | 30 ++++++++++++++++++++++++++++++
drivers/md/dm.c | 31 ++++++++++++++++++++++++++++---
include/linux/device-mapper.h | 6 ++++++
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 28955b94d2b2..6006d5d4b06e 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 dfb75979e455..e8226359c8f7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -825,6 +825,14 @@ 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;
@@ -851,9 +859,14 @@ 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);
@@ -1202,6 +1215,11 @@ 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)
@@ -1256,6 +1274,11 @@ 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.
*/
@@ -1270,6 +1293,8 @@ 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.
*/
--
2.11.0
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