When T10 PI is enabled on a backing device for the iblock backstore, the
PI SGL for the entire command is attached to the first bio only. This
works fine if the command is covered by a single bio, but results in
integrity verification errors for the other bios in a multi-bio command.
Split the PI SGL across the bios in the command, so each bip contains
the protection information for the data in the bio. In a multi-bio
command, store where we left off in the PI SGL so we know where to start
with the next bio.
Signed-off-by: Greg Edwards <gedwards@xxxxxxx>
---
This patch depends on commit 359f642700f2 ("block: move
bio_integrity_{intervals,bytes} into blkdev.h") in Jens' block for-next branch.
drivers/target/target_core_iblock.c | 60 +++++++++++++++++++++--------
1 file changed, 44 insertions(+), 16 deletions(-)
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index ce1321a5cb7b..d3ab83282f61 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -635,7 +635,8 @@ static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
}
static int
-iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
+iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
+ struct scatterlist **sgl, unsigned int *skip)
{
struct se_device *dev = cmd->se_dev;
struct blk_integrity *bi;
@@ -643,6 +644,7 @@ iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct scatterlist *sg;
int i, rc;
+ unsigned int size, nr_pages, len, off;
bi = bdev_get_integrity(ib_dev->ibd_bd);
if (!bi) {
@@ -650,32 +652,52 @@ iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
return -ENODEV;
}
- bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
+ nr_pages = min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES);
+ bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
if (IS_ERR(bip)) {
pr_err("Unable to allocate bio_integrity_payload\n");
return PTR_ERR(bip);
}
- bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
- dev->prot_length;
- bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
+ bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
+ bip_set_seed(bip, bio->bi_iter.bi_sector);
pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
(unsigned long long)bip->bip_iter.bi_sector);
- for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
+ size = bip->bip_iter.bi_size;
+ for_each_sg(*sgl, sg, nr_pages, i) {
- rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
- sg->offset);
- if (rc != sg->length) {
+ len = sg->length - *skip;
+ off = sg->offset + *skip;
+
+ if (*skip)
+ *skip = 0;
+
+ if (len > size) {
+ len = size;
+ *skip = len;
+ }
+
+ rc = bio_integrity_add_page(bio, sg_page(sg), len, off);
+ if (rc != len) {
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);
+ sg_page(sg), len, off);
+
+ size -= len;
+ if (!size)
+ break;
}
+ if (*skip == 0)
+ *sgl = sg_next(sg);
+ else
+ *sgl = sg;
+
return 0;
}
@@ -686,12 +708,12 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
struct se_device *dev = cmd->se_dev;
sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
struct iblock_req *ibr;
- struct bio *bio, *bio_start;
+ struct bio *bio;
struct bio_list list;
- struct scatterlist *sg;
+ struct scatterlist *sg, *sg_prot = cmd->t_prot_sg;
u32 sg_num = sgl_nents;
- unsigned bio_cnt;
- int i, op, op_flags = 0;
+ unsigned int bio_cnt, skip = 0;
+ int i, rc, op, op_flags = 0;
if (data_direction == DMA_TO_DEVICE) {
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
@@ -726,7 +748,6 @@ 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);
@@ -741,6 +762,13 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
*/
while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
!= sg->length) {
+ if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
+ rc = iblock_alloc_bip(cmd, bio, &sg_prot,
+ &skip);
+ if (rc)
+ goto fail_put_bios;
+ }
+
if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
iblock_submit_bios(&list);
bio_cnt = 0;
@@ -762,7 +790,7 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
}
if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
- int rc = iblock_alloc_bip(cmd, bio_start);
+ rc = iblock_alloc_bip(cmd, bio, &sg_prot, &skip);
if (rc)
goto fail_put_bios;
}
--
2.17.1
