From: Mike Snitzer <snitzer@redhat.com>
Date: Mon, 4 Dec 2017 21:07:37 -0500
Subject: [PATCH] dm: introduce DM_TYPE_NVME_BIO_BASED
Git-commit: 22c11858e8002592c59ebb762e4e42dc634bf84f
Patch-mainline: v4.16-rc1
References: bsc#1104967,FATE#325924
If dm_table_determine_type() establishes DM_TYPE_NVME_BIO_BASED then
all devices in the DM table do not support partial completions. Also,
the table has a single immutable target that doesn't require DM core to
split bios.
This will enable adding NVMe optimizations to bio-based DM.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/md/dm-table.c | 54 ++++++++++++++++++++++++++++++++++++++-----
drivers/md/dm.c | 2 ++
include/linux/device-mapper.h | 1 +
3 files changed, 51 insertions(+), 6 deletions(-)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 504e79bc3a55..ad4ac294dd57 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -866,7 +866,8 @@ EXPORT_SYMBOL(dm_consume_args);
static bool __table_type_bio_based(enum dm_queue_mode table_type)
{
return (table_type == DM_TYPE_BIO_BASED ||
- table_type == DM_TYPE_DAX_BIO_BASED);
+ table_type == DM_TYPE_DAX_BIO_BASED ||
+ table_type == DM_TYPE_NVME_BIO_BASED);
}
static bool __table_type_request_based(enum dm_queue_mode table_type)
@@ -909,6 +910,8 @@ static bool dm_table_supports_dax(struct dm_table *t)
return true;
}
+static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
+
static int dm_table_determine_type(struct dm_table *t)
{
unsigned i;
@@ -923,6 +926,14 @@ static int dm_table_determine_type(struct dm_table *t)
/* target already set the table's type */
if (t->type == DM_TYPE_BIO_BASED)
return 0;
+ else if (t->type == DM_TYPE_NVME_BIO_BASED) {
+ if (!dm_table_does_not_support_partial_completion(t)) {
+ DMERR("nvme bio-based is only possible with devices"
+ " that don't support partial completion");
+ return -EINVAL;
+ }
+ /* Fallthru, also verify all devices are blk-mq */
+ }
BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
goto verify_rq_based;
}
@@ -937,8 +948,8 @@ static int dm_table_determine_type(struct dm_table *t)
bio_based = 1;
if (bio_based && request_based) {
- DMWARN("Inconsistent table: different target types"
- " can't be mixed up");
+ DMERR("Inconsistent table: different target types"
+ " can't be mixed up");
return -EINVAL;
}
}
@@ -959,8 +970,14 @@ static int dm_table_determine_type(struct dm_table *t)
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
if (dm_table_supports_dax(t) ||
- (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED))
+ (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
+ } else if ((dm_table_get_immutable_target(t) &&
+ dm_table_does_not_support_partial_completion(t)) ||
+ (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED)) {
+ t->type = DM_TYPE_NVME_BIO_BASED;
+ goto verify_rq_based;
+ }
return 0;
}
@@ -980,7 +997,8 @@ static int dm_table_determine_type(struct dm_table *t)
* (e.g. request completion process for partial completion.)
*/
if (t->num_targets > 1) {
- DMWARN("Request-based dm doesn't support multiple targets yet");
+ DMERR("%s DM doesn't support multiple targets",
+ t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
return -EINVAL;
}
@@ -997,6 +1015,15 @@ static int dm_table_determine_type(struct dm_table *t)
return 0;
}
+ tgt = dm_table_get_immutable_target(t);
+ if (!tgt) {
+ DMERR("table load rejected: immutable target is required");
+ return -EINVAL;
+ } else if (tgt->max_io_len) {
+ DMERR("table load rejected: immutable target that splits IO is not supported");
+ return -EINVAL;
+ }
+
/* Non-request-stackable devices can't be used for request-based dm */
list_for_each_entry(dd, devices, list) {
struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
@@ -1018,7 +1045,8 @@ static int dm_table_determine_type(struct dm_table *t)
}
t->all_blk_mq = mq_count > 0;
- if (t->type == DM_TYPE_MQ_REQUEST_BASED && !t->all_blk_mq) {
+ if (!t->all_blk_mq &&
+ (t->type == DM_TYPE_MQ_REQUEST_BASED || t->type == DM_TYPE_NVME_BIO_BASED)) {
DMERR("table load rejected: all devices are not blk-mq request-stackable");
return -EINVAL;
}
@@ -1708,6 +1736,20 @@ static bool dm_table_all_devices_attribute(struct dm_table *t,
return true;
}
+static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ char b[BDEVNAME_SIZE];
+
+ /* For now, NVMe devices are the only devices of this class */
+ return (strncmp(bdevname(dev->bdev, b), "nvme", 3) == 0);
+}
+
+static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
+{
+ return dm_table_all_devices_attribute(t, device_no_partial_completion);
+}
+
static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index cbb4ae5051fc..a1bd7a6ff522 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2073,6 +2073,7 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
break;
case DM_TYPE_BIO_BASED:
case DM_TYPE_DAX_BIO_BASED:
+ case DM_TYPE_NVME_BIO_BASED:
dm_init_normal_md_queue(md);
blk_queue_make_request(md->queue, dm_make_request);
break;
@@ -2780,6 +2781,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_qu
switch (type) {
case DM_TYPE_BIO_BASED:
case DM_TYPE_DAX_BIO_BASED:
+ case DM_TYPE_NVME_BIO_BASED:
pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
io_front_pad = roundup(front_pad, __alignof__(struct dm_io)) + offsetof(struct dm_io, tio);
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 0e518d2ee280..41ec228b02a6 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -28,6 +28,7 @@ enum dm_queue_mode {
DM_TYPE_REQUEST_BASED = 2,
DM_TYPE_MQ_REQUEST_BASED = 3,
DM_TYPE_DAX_BIO_BASED = 4,
+ DM_TYPE_NVME_BIO_BASED = 5,
};
typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
--
2.16.4