[dm-devel] [PATCH v2 2/9] dm: eliminate 'split_discard_bios' flag from DM target interface
Mike Snitzer
snitzer at redhat.com
Wed Feb 20 21:44:29 UTC 2019
There is no need to have DM core split discards on behalf of a DM target
now that blk_queue_split() handles splitting discards based on the
queue_limits. A DM target just needs to set max_discard_sectors,
discard_granularity, etc, in queue_limits.
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
drivers/md/dm-cache-target.c | 1 -
drivers/md/dm-raid.c | 14 +++++++++-----
drivers/md/dm-thin.c | 1 -
drivers/md/dm-zoned-target.c | 1 -
drivers/md/dm.c | 28 ++++++----------------------
include/linux/device-mapper.h | 6 ------
include/uapi/linux/dm-ioctl.h | 4 ++--
7 files changed, 17 insertions(+), 38 deletions(-)
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index b29a8327eed1..adc529f12b6b 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -2496,7 +2496,6 @@ static int cache_create(struct cache_args *ca, struct cache **result)
ti->num_discard_bios = 1;
ti->discards_supported = true;
- ti->split_discard_bios = false;
ti->per_io_data_size = sizeof(struct per_bio_data);
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index adcfe8ae10aa..9fdef6897316 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -2986,11 +2986,6 @@ static void configure_discard_support(struct raid_set *rs)
}
}
- /*
- * RAID1 and RAID10 personalities require bio splitting,
- * RAID0/4/5/6 don't and process large discard bios properly.
- */
- ti->split_discard_bios = !!(rs_is_raid1(rs) || rs_is_raid10(rs));
ti->num_discard_bios = 1;
}
@@ -3747,6 +3742,15 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
blk_limits_io_min(limits, chunk_size);
blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs));
+
+ /*
+ * RAID1 and RAID10 personalities require bio splitting,
+ * RAID0/4/5/6 don't and process large discard bios properly.
+ */
+ if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
+ limits->discard_granularity = chunk_size;
+ limits->max_discard_sectors = chunk_size;
+ }
}
static void raid_postsuspend(struct dm_target *ti)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index e83b63608262..0d9ded0f5e50 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -4227,7 +4227,6 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
if (tc->pool->pf.discard_enabled) {
ti->discards_supported = true;
ti->num_discard_bios = 1;
- ti->split_discard_bios = false;
}
mutex_unlock(&dm_thin_pool_table.mutex);
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index 6af5babe6837..8865c1709e16 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -727,7 +727,6 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->per_io_data_size = sizeof(struct dmz_bioctx);
ti->flush_supported = true;
ti->discards_supported = true;
- ti->split_discard_bios = true;
/* The exposed capacity is the number of chunks that can be mapped */
ti->len = (sector_t)dmz_nr_chunks(dmz->metadata) << dev->zone_nr_sectors_shift;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7a774fcd0194..b988e178a523 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1478,17 +1478,10 @@ 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)
-{
- return ti->split_discard_bios;
-}
-
static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
- unsigned num_bios, bool is_split_required)
+ unsigned num_bios)
{
- unsigned len;
+ unsigned len = ci->sector_count;
/*
* Even though the device advertised support for this type of
@@ -1499,38 +1492,29 @@ static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *
if (!num_bios)
return -EOPNOTSUPP;
- if (!is_split_required)
- len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
- else
- len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
-
__send_duplicate_bios(ci, ti, num_bios, &len);
- ci->sector += len;
- ci->sector_count -= len;
-
return 0;
}
static int __send_discard(struct clone_info *ci, struct dm_target *ti)
{
- return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti),
- is_split_required_for_discard(ti));
+ return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti));
}
static int __send_secure_erase(struct clone_info *ci, struct dm_target *ti)
{
- return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti), false);
+ return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti));
}
static int __send_write_same(struct clone_info *ci, struct dm_target *ti)
{
- return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti), false);
+ return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti));
}
static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)
{
- return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti), false);
+ return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti));
}
static bool is_abnormal_io(struct bio *bio)
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index e528baebad69..0f5b3d7c6cb3 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -315,12 +315,6 @@ struct dm_target {
* whether or not its underlying devices have support.
*/
bool discards_supported:1;
-
- /*
- * Set if the target required discard bios to be split
- * on max_io_len boundary.
- */
- bool split_discard_bios:1;
};
/* Each target can link one of these into the table */
diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h
index d1e49514977b..f396a82dfd3e 100644
--- a/include/uapi/linux/dm-ioctl.h
+++ b/include/uapi/linux/dm-ioctl.h
@@ -270,9 +270,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
#define DM_VERSION_MAJOR 4
-#define DM_VERSION_MINOR 39
+#define DM_VERSION_MINOR 40
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2018-04-03)"
+#define DM_VERSION_EXTRA "-ioctl (2019-01-18)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
--
2.15.0
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