Re: [PATCH-v2 11/17] target/iblock: Add blk_integrity + BIP passthroughsupport

From: Sagi Grimberg
Date: Sun Jan 19 2014 - 07:21:19 EST

On 1/19/2014 4:44 AM, Nicholas A. Bellinger wrote:
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch adds blk_integrity passthrough support for block_device
backends using IBLOCK.

Nice!

This includes iblock_alloc_bip() + setup of bio_integrity_payload
information that attaches to the leading struct bio once bio_list
is populated during fast-path iblock_execute_rw() I/O dispatch.

It also updates setup in iblock_configure_device() to detect modes
of protection + se dev->dev_attrib.pi_prot_type accordingly, along
with creating required bio_set integrity mempools.

Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/Kconfig | 1 +
drivers/target/target_core_iblock.c | 91 ++++++++++++++++++++++++++++++++++-
2 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/drivers/target/Kconfig b/drivers/target/Kconfig
index 50aad2e..dc2d84a 100644
--- a/drivers/target/Kconfig
+++ b/drivers/target/Kconfig
@@ -14,6 +14,7 @@ if TARGET_CORE
config TCM_IBLOCK
tristate "TCM/IBLOCK Subsystem Plugin for Linux/BLOCK"
+ select BLK_DEV_INTEGRITY
help
Say Y here to enable the TCM/IBLOCK subsystem plugin for non-buffered
access to Linux/Block devices using BIO
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 15d9121..293d9b0 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -91,6 +91,7 @@ static int iblock_configure_device(struct se_device *dev)
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct request_queue *q;
struct block_device *bd = NULL;
+ struct blk_integrity *bi;
fmode_t mode;
int ret = -ENOMEM;
@@ -155,8 +156,40 @@ static int iblock_configure_device(struct se_device *dev)
if (blk_queue_nonrot(q))
dev->dev_attrib.is_nonrot = 1;
+ bi = bdev_get_integrity(bd);
+ if (bi) {
+ struct bio_set *bs = ib_dev->ibd_bio_set;
+
+ if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
+ !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
+ pr_err("IBLOCK export of blk_integrity: %s not"
+ " supported\n", bi->name);
+ ret = -ENOSYS;
+ goto out_blkdev_put;
+ }

Please remind me why we ignore IP-CSUM guard type again?
MKP, will this be irrelevant for the initiator as well? if so, I don't see a reason to expose this in RDMA verbs.

+
+ if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
+ dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
+ } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
+ dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
+ }
+
+ if (dev->dev_attrib.pi_prot_type) {
+ if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
+ pr_err("Unable to allocate bioset for PI\n");
+ ret = -ENOMEM;
+ goto out_blkdev_put;
+ }
+ pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
+ bs->bio_integrity_pool);
+ }
+ dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
+ }
+
return 0;
+out_blkdev_put:
+ blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
out_free_bioset:
bioset_free(ib_dev->ibd_bio_set);
ib_dev->ibd_bio_set = NULL;
@@ -170,8 +203,10 @@ static void iblock_free_device(struct se_device *dev)
if (ib_dev->ibd_bd != NULL)
blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
- if (ib_dev->ibd_bio_set != NULL)
+ if (ib_dev->ibd_bio_set != NULL) {
+ bioset_integrity_free(ib_dev->ibd_bio_set);
bioset_free(ib_dev->ibd_bio_set);
+ }
kfree(ib_dev);
}
@@ -586,13 +621,58 @@ static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
return bl;
}
+static int
+iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
+{
+ struct se_device *dev = cmd->se_dev;
+ struct blk_integrity *bi;
+ struct bio_integrity_payload *bip;
+ struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
+ struct scatterlist *sg;
+ int i, rc;
+
+ bi = bdev_get_integrity(ib_dev->ibd_bd);
+ if (!bi) {
+ pr_err("Unable to locate bio_integrity\n");
+ return -ENODEV;
+ }
+
+ bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
+ if (!bip) {
+ pr_err("Unable to allocate bio_integrity_payload\n");
+ return -ENOMEM;
+ }
+
+ bip->bip_size = (cmd->data_length / dev->dev_attrib.block_size) *
+ dev->prot_length;
+ bip->bip_sector = bio->bi_sector;
+
+ pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_size,
+ (unsigned long long)bip->bip_sector);
+
+ for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
+
+ rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
+ sg->offset);
+ if (rc != sg->length) {
+ pr_err("bio_integrity_add_page() failed; %d\n", rc);
+ return -ENOMEM;
+ }
+
+ pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
+ sg_page(sg), sg->length, sg->offset);
+ }
+
+ return 0;
+}
+
static sense_reason_t
iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
enum dma_data_direction data_direction)
{
struct se_device *dev = cmd->se_dev;
struct iblock_req *ibr;
- struct bio *bio;
+ struct bio *bio, *bio_start;
struct bio_list list;
struct scatterlist *sg;
u32 sg_num = sgl_nents;
@@ -655,6 +735,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
if (!bio)
goto fail_free_ibr;
+ bio_start = bio;
bio_list_init(&list);
bio_list_add(&list, bio);
@@ -688,6 +769,12 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
sg_num--;
}
+ if (cmd->prot_type) {
+ int rc = iblock_alloc_bip(cmd, bio_start);
+ if (rc)
+ goto fail_put_bios;
+ }
+
iblock_submit_bios(&list, rw);
iblock_complete_cmd(cmd);
return 0;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/