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dm: remove special-casing of bio-based immutable singleton target on …
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…NVMe

Since commit 5a6c35f ("block: remove direct_make_request") there
is no benefit to DM special-casing NVMe. Remove all code used to
establish DM_TYPE_NVME_BIO_BASED.

Signed-off-by: Mike Snitzer <[email protected]>
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@snitm
snitm committed Oct 7, 2020
1 parent 61931c0 commit 9c37de2
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Showing 3 changed files with 7 additions and 81 deletions.
32 changes: 2 additions & 30 deletions drivers/md/dm-table.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -804,8 +804,7 @@ 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_NVME_BIO_BASED);
table_type == DM_TYPE_DAX_BIO_BASED);
}

static bool __table_type_request_based(enum dm_queue_mode table_type)
Expand Down Expand Up @@ -861,8 +860,6 @@ 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 device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
Expand Down Expand Up @@ -892,7 +889,6 @@ static int dm_table_determine_type(struct dm_table *t)
goto verify_bio_based;
}
BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
goto verify_rq_based;
}

Expand Down Expand Up @@ -931,15 +927,6 @@ static int dm_table_determine_type(struct dm_table *t)
if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
(list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
} else {
/* Check if upgrading to NVMe bio-based is valid or required */
tgt = dm_table_get_immutable_target(t);
if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
t->type = DM_TYPE_NVME_BIO_BASED;
goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
} else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
t->type = DM_TYPE_NVME_BIO_BASED;
}
}
return 0;
}
Expand All @@ -956,8 +943,7 @@ static int dm_table_determine_type(struct dm_table *t)
* (e.g. request completion process for partial completion.)
*/
if (t->num_targets > 1) {
DMERR("%s DM doesn't support multiple targets",
t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
DMERR("request-based DM doesn't support multiple targets");
return -EINVAL;
}

Expand Down Expand Up @@ -1651,20 +1637,6 @@ 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", 4) == 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)
{
Expand Down
55 changes: 5 additions & 50 deletions drivers/md/dm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -975,7 +975,7 @@ static void clone_endio(struct bio *bio)
dm_endio_fn endio = tio->ti->type->end_io;
struct bio *orig_bio = io->orig_bio;

if (unlikely(error == BLK_STS_TARGET) && md->type != DM_TYPE_NVME_BIO_BASED) {
if (unlikely(error == BLK_STS_TARGET)) {
if (bio_op(bio) == REQ_OP_DISCARD &&
!bio->bi_disk->queue->limits.max_discard_sectors)
disable_discard(md);
Expand Down Expand Up @@ -1626,45 +1626,6 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
return ret;
}

/*
* Optimized variant of __split_and_process_bio that leverages the
* fact that targets that use it do _not_ have a need to split bios.
*/
static blk_qc_t __process_bio(struct mapped_device *md, struct dm_table *map,
struct bio *bio)
{
struct clone_info ci;
blk_qc_t ret = BLK_QC_T_NONE;
int error = 0;

init_clone_info(&ci, md, map, bio);

if (bio->bi_opf & REQ_PREFLUSH) {
error = __send_empty_flush(&ci);
/* dec_pending submits any data associated with flush */
} else {
struct dm_target_io *tio;
struct dm_target *ti = md->immutable_target;

if (WARN_ON_ONCE(!ti)) {
error = -EIO;
goto out;
}

ci.bio = bio;
ci.sector_count = bio_sectors(bio);
if (__process_abnormal_io(&ci, ti, &error))
goto out;

tio = alloc_tio(&ci, ti, 0, GFP_NOIO);
ret = __clone_and_map_simple_bio(&ci, tio, NULL);
}
out:
/* drop the extra reference count */
dec_pending(ci.io, errno_to_blk_status(error));
return ret;
}

static blk_qc_t dm_submit_bio(struct bio *bio)
{
struct mapped_device *md = bio->bi_disk->private_data;
Expand Down Expand Up @@ -1710,10 +1671,7 @@ static blk_qc_t dm_submit_bio(struct bio *bio)
if (is_abnormal_io(bio))
blk_queue_split(&bio);

if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
ret = __process_bio(md, map, bio);
else
ret = __split_and_process_bio(md, map, bio);
ret = __split_and_process_bio(md, map, bio);
out:
dm_put_live_table(md, srcu_idx);
return ret;
Expand Down Expand Up @@ -2038,11 +1996,10 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
if (request_based)
dm_stop_queue(q);

if (request_based || md->type == DM_TYPE_NVME_BIO_BASED) {
if (request_based) {
/*
* Leverage the fact that request-based DM targets and
* NVMe bio based targets are immutable singletons
* - used to optimize both __process_bio and dm_mq_queue_rq
* Leverage the fact that request-based DM targets are
* immutable singletons - used to optimize dm_mq_queue_rq.
*/
md->immutable_target = dm_table_get_immutable_target(t);
}
Expand Down Expand Up @@ -2164,7 +2121,6 @@ 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:
break;
case DM_TYPE_NONE:
WARN_ON_ONCE(true);
Expand Down Expand Up @@ -2922,7 +2878,6 @@ 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);
Expand Down
1 change: 0 additions & 1 deletion include/linux/device-mapper.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,6 @@ enum dm_queue_mode {
DM_TYPE_BIO_BASED = 1,
DM_TYPE_REQUEST_BASED = 2,
DM_TYPE_DAX_BIO_BASED = 3,
DM_TYPE_NVME_BIO_BASED = 4,
};

typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
Expand Down

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