[PATCHv5 9/9] blk-integrity: improved sg segment mapping

Keith Busch
2024-09-13T18:29:19Z

Make the integrity mapping more like data mapping, blk_rq_map_sg. Use
the request to validate the segment count, and update the callers so
they don't have to.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
block/blk-integrity.c | 15 +++++++++++----
drivers/nvme/host/rdma.c | 4 ++--
drivers/scsi/scsi_lib.c | 11 +++--------
include/linux/blk-integrity.h | 6 ++----
4 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 1d82b18e06f8e..549480aa2a069 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -62,19 +62,20 @@ int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
*
* Description: Map the integrity vectors in request into a
* scatterlist. The scatterlist must be big enough to hold all
- * elements. I.e. sized using blk_rq_count_integrity_sg().
+ * elements. I.e. sized using blk_rq_count_integrity_sg() or
+ * rq->nr_integrity_segments.
*/
-int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
- struct scatterlist *sglist)
+int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist)
{
struct bio_vec iv, ivprv = { NULL };
+ struct request_queue *q = rq->q;
struct scatterlist *sg = NULL;
+ struct bio *bio = rq->bio;
unsigned int segments = 0;
struct bvec_iter iter;
int prev = 0;

bio_for_each_integrity_vec(iv, bio, iter) {
-
if (prev) {
if (!biovec_phys_mergeable(q, &ivprv, &iv))
goto new_segment;
@@ -102,6 +103,12 @@ int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
if (sg)
sg_mark_end(sg);

+ /*
+ * Something must have been wrong if the figured number of segment
+ * is bigger than number of req's physical integrity segments
+ */
+ BUG_ON(segments > blk_rq_nr_phys_segments(rq));
+ BUG_ON(segments > queue_max_integrity_segments(q));
return segments;
}
EXPORT_SYMBOL(blk_rq_map_integrity_sg);
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 256466bdaee7c..c8fd0e8f02375 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1504,8 +1504,8 @@ static int nvme_rdma_dma_map_req(struct ib_device *ibdev, struct request *rq,
goto out_unmap_sg;
}

- req->metadata_sgl->nents = blk_rq_map_integrity_sg(rq->q,
- rq->bio, req->metadata_sgl->sg_table.sgl);
+ req->metadata_sgl->nents = blk_rq_map_integrity_sg(rq,
+ req->metadata_sgl->sg_table.sgl);
*pi_count = ib_dma_map_sg(ibdev,
req->metadata_sgl->sg_table.sgl,
req->metadata_sgl->nents,
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c602b0af745ca..c2f6d0e1c03e7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1163,7 +1163,6 @@ blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)

if (blk_integrity_rq(rq)) {
struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
- int ivecs;

if (WARN_ON_ONCE(!prot_sdb)) {
/*
@@ -1175,19 +1174,15 @@ blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
goto out_free_sgtables;
}

- ivecs = rq->nr_integrity_segments;
- if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
+ if (sg_alloc_table_chained(&prot_sdb->table,
+ rq->nr_integrity_segments,
prot_sdb->table.sgl,
SCSI_INLINE_PROT_SG_CNT)) {
ret = BLK_STS_RESOURCE;
goto out_free_sgtables;
}

- count = blk_rq_map_integrity_sg(rq->q, rq->bio,
- prot_sdb->table.sgl);
- BUG_ON(count > ivecs);
- BUG_ON(count > queue_max_integrity_segments(rq->q));
-
+ count = blk_rq_map_integrity_sg(rq, prot_sdb->table.sgl);
cmd->prot_sdb = prot_sdb;
cmd->prot_sdb->table.nents = count;
}
diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index 793dbb1e0672d..676f8f860c474 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h
@@ -25,8 +25,7 @@ static inline bool queue_limits_stack_integrity_bdev(struct queue_limits *t,
}

#ifdef CONFIG_BLK_DEV_INTEGRITY
-int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
- struct scatterlist *);
+int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
ssize_t bytes, u32 seed);
@@ -98,8 +97,7 @@ static inline int blk_rq_count_integrity_sg(struct request_queue *q,
{
return 0;
}
-static inline int blk_rq_map_integrity_sg(struct request_queue *q,
- struct bio *b,
+static inline int blk_rq_map_integrity_sg(struct request *q,
struct scatterlist *s)
{
return 0;
--
2.43.5