scsi: replace "scsi_data_buffer" with "sg_table" in SG functions

Replace parameter "struct scsi_data_buffer" with "struct sg_table" in
SG alloc/free functions to make them generic.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 23 insertions, 18 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8106515d1df8..4229c183648b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -583,14 +583,14 @@ static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
         return mempool_alloc(sgp->pool, gfp_mask);
 }
 
-static void scsi_free_sgtable(struct scsi_data_buffer *sdb, bool mq)
+static void scsi_free_sgtable(struct sg_table *table, bool mq)
 {
-        if (mq && sdb->table.orig_nents <= SCSI_MAX_SG_SEGMENTS)
+        if (mq && table->orig_nents <= SCSI_MAX_SG_SEGMENTS)
                 return;
-        __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, mq, scsi_sg_free);
+        __sg_free_table(table, SCSI_MAX_SG_SEGMENTS, mq, scsi_sg_free);
 }
 
-static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, bool mq)
+static int scsi_alloc_sgtable(struct sg_table *table, int nents, bool mq)
 {
         struct scatterlist *first_chunk = NULL;
         int ret;
@@ -599,17 +599,17 @@ static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, bool mq)
 
         if (mq) {
                 if (nents <= SCSI_MAX_SG_SEGMENTS) {
-                        sdb->table.nents = sdb->table.orig_nents = nents;
-                        sg_init_table(sdb->table.sgl, nents);
+                        table->nents = table->orig_nents = nents;
+                        sg_init_table(table->sgl, nents);
                         return 0;
                 }
-                first_chunk = sdb->table.sgl;
+                first_chunk = table->sgl;
         }
 
-        ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
+        ret = __sg_alloc_table(table, nents, SCSI_MAX_SG_SEGMENTS,
                                first_chunk, GFP_ATOMIC, scsi_sg_alloc);
         if (unlikely(ret))
-                scsi_free_sgtable(sdb, mq);
+                scsi_free_sgtable(table, mq);
         return ret;
 }
 
@@ -625,12 +625,17 @@ static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
 
 static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
 {
+        struct scsi_data_buffer *sdb;
+
         if (cmd->sdb.table.nents)
-                scsi_free_sgtable(&cmd->sdb, true);
-        if (cmd->request->next_rq && cmd->request->next_rq->special)
-                scsi_free_sgtable(cmd->request->next_rq->special, true);
+                scsi_free_sgtable(&cmd->sdb.table, true);
+        if (cmd->request->next_rq) {
+                sdb = cmd->request->next_rq->special;
+                if (sdb)
+                        scsi_free_sgtable(&sdb->table, true);
+        }
         if (scsi_prot_sg_count(cmd))
-                scsi_free_sgtable(cmd->prot_sdb, true);
+                scsi_free_sgtable(&cmd->prot_sdb->table, true);
 }
 
 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
@@ -669,19 +674,19 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
 static void scsi_release_buffers(struct scsi_cmnd *cmd)
 {
         if (cmd->sdb.table.nents)
-                scsi_free_sgtable(&cmd->sdb, false);
+                scsi_free_sgtable(&cmd->sdb.table, false);
 
         memset(&cmd->sdb, 0, sizeof(cmd->sdb));
 
         if (scsi_prot_sg_count(cmd))
-                scsi_free_sgtable(cmd->prot_sdb, false);
+                scsi_free_sgtable(&cmd->prot_sdb->table, false);
 }
 
 static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
 {
         struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
 
-        scsi_free_sgtable(bidi_sdb, false);
+        scsi_free_sgtable(&bidi_sdb->table, false);
         kmem_cache_free(scsi_sdb_cache, bidi_sdb);
         cmd->request->next_rq->special = NULL;
 }
@@ -1085,7 +1090,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
         /*
          * If sg table allocation fails, requeue request later.
          */
-        if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
+        if (unlikely(scsi_alloc_sgtable(&sdb->table, req->nr_phys_segments,
                                         req->mq_ctx != NULL)))
                 return BLKPREP_DEFER;
 
@@ -1158,7 +1163,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 
                 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
 
-                if (scsi_alloc_sgtable(prot_sdb, ivecs, is_mq)) {
+                if (scsi_alloc_sgtable(&prot_sdb->table, ivecs, is_mq)) {
                         error = BLKPREP_DEFER;
                         goto err_exit;
                 }