target/iblock: Add blk_integrity + BIP passthrough support

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

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@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 90 insertions, 2 deletions

diff --git a/drivers/target/Kconfig b/drivers/target/Kconfig
index 50aad2eeed6e..dc2d84ac5a0e 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 15d9121a517e..293d9b081e8a 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;
+                }
+
+                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;