[PATCH 09/15] scsi: add scsi_alloc_integrity_sgtables() for integrity process

Jinyoung CHOI
2023-05-03T10:18:29Z

Separate the integrity mapping process of scsi_alloc_sgtables() into a
new function for readability.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Jinyoung Choi <j-young.choi@samsung.com>
---
drivers/scsi/scsi_lib.c | 71 ++++++++++++++++++++++-------------------
1 file changed, 38 insertions(+), 33 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7c569a42aa4..89cf21345e1a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1003,6 +1003,40 @@ static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
sdev->host->hostt->dma_need_drain(rq);
}

+static blk_status_t scsi_alloc_integrity_sgtables(struct scsi_cmnd *cmd)
+{
+ struct request *rq = scsi_cmd_to_rq(cmd);
+ struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
+ int count, ivecs;
+
+ if (WARN_ON_ONCE(!prot_sdb)) {
+ /*
+ * This can happen if someone (e.g. multipath)
+ * queues a command to a device on an adapter
+ * that does not support DIX.
+ */
+ return BLK_STS_IOERR;
+ }
+
+ ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
+
+ if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
+ prot_sdb->table.sgl,
+ SCSI_INLINE_PROT_SG_CNT)) {
+ return BLK_STS_RESOURCE;
+ }
+
+ 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));
+
+ cmd->prot_sdb = prot_sdb;
+ cmd->prot_sdb->table.nents = count;
+
+ return BLK_STS_OK;
+}
+
/**
* scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists
* @cmd: SCSI command data structure to initialize.
@@ -1021,7 +1055,7 @@ blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
struct request *rq = scsi_cmd_to_rq(cmd);
unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
struct scatterlist *last_sg = NULL;
- blk_status_t ret;
+ blk_status_t ret = BLK_STS_OK;
bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq);
int count;

@@ -1071,40 +1105,11 @@ blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
cmd->sdb.length = blk_rq_payload_bytes(rq);

if (blk_integrity_rq(rq)) {
- struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
- int ivecs;
-
- if (WARN_ON_ONCE(!prot_sdb)) {
- /*
- * This can happen if someone (e.g. multipath)
- * queues a command to a device on an adapter
- * that does not support DIX.
- */
- ret = BLK_STS_IOERR;
- goto out_free_sgtables;
- }
-
- ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
-
- if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
- 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));
-
- cmd->prot_sdb = prot_sdb;
- cmd->prot_sdb->table.nents = count;
+ ret = scsi_alloc_integrity_sgtables(cmd);
+ if (ret != BLK_STS_OK)
+ scsi_free_sgtables(cmd);
}

- return BLK_STS_OK;
-out_free_sgtables:
- scsi_free_sgtables(cmd);
return ret;
}
EXPORT_SYMBOL(scsi_alloc_sgtables);
--
2.34.1