scsi_debug: support sg chaining

Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4947dfe..72ee4c9 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -38,6 +38,7 @@
 #include <linux/proc_fs.h>
 #include <linux/vmalloc.h>
 #include <linux/moduleparam.h>
+#include <linux/scatterlist.h>
 
 #include <linux/blkdev.h>
 #include "scsi.h"
@@ -600,7 +601,7 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
        int k, req_len, act_len, len, active;
        void * kaddr;
        void * kaddr_off;
-       struct scatterlist * sgpnt;
+       struct scatterlist * sg;
 
        if (0 == scp->request_bufflen)
                return 0;
@@ -619,16 +620,16 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                        scp->resid = req_len - act_len;
                return 0;
        }
-       sgpnt = (struct scatterlist *)scp->request_buffer;
        active = 1;
-       for (k = 0, req_len = 0, act_len = 0; k < scp->use_sg; ++k, ++sgpnt) {
+       req_len = act_len = 0;
+       scsi_for_each_sg(scp, sg, scp->use_sg, k) {
                if (active) {
                        kaddr = (unsigned char *)
-                               kmap_atomic(sgpnt->page, KM_USER0);
+                               kmap_atomic(sg->page, KM_USER0);
                        if (NULL == kaddr)
                                return (DID_ERROR << 16);
-                       kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
-                       len = sgpnt->length;
+                       kaddr_off = (unsigned char *)kaddr + sg->offset;
+                       len = sg->length;
                        if ((req_len + len) > arr_len) {
                                active = 0;
                                len = arr_len - req_len;
@@ -637,7 +638,7 @@ static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                        kunmap_atomic(kaddr, KM_USER0);
                        act_len += len;
                }
-               req_len += sgpnt->length;
+               req_len += sg->length;
        }
        if (scp->resid)
                scp->resid -= act_len;
@@ -653,7 +654,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
        int k, req_len, len, fin;
        void * kaddr;
        void * kaddr_off;
-       struct scatterlist * sgpnt;
+       struct scatterlist * sg;
 
        if (0 == scp->request_bufflen)
                return 0;
@@ -668,13 +669,14 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                memcpy(arr, scp->request_buffer, len);
                return len;
        }
-       sgpnt = (struct scatterlist *)scp->request_buffer;
-       for (k = 0, req_len = 0, fin = 0; k < scp->use_sg; ++k, ++sgpnt) {
-               kaddr = (unsigned char *)kmap_atomic(sgpnt->page, KM_USER0);
+       sg = scsi_sglist(scp);
+       req_len = fin = 0;
+       for (k = 0; k < scp->use_sg; ++k, sg = sg_next(sg)) {
+               kaddr = (unsigned char *)kmap_atomic(sg->page, KM_USER0);
                if (NULL == kaddr)
                        return -1;
-               kaddr_off = (unsigned char *)kaddr + sgpnt->offset;
-               len = sgpnt->length;
+               kaddr_off = (unsigned char *)kaddr + sg->offset;
+               len = sg->length;
                if ((req_len + len) > max_arr_len) {
                        len = max_arr_len - req_len;
                        fin = 1;
@@ -683,7 +685,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                kunmap_atomic(kaddr, KM_USER0);
                if (fin)
                        return req_len + len;
-               req_len += sgpnt->length;
+               req_len += sg->length;
        }
        return req_len;
 }