scsi: convert to using sg helpers

This converts the SCSI mid layer to using the sg helpers for looking up
sg elements, instead of doing it manually.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 207f1aa08869f209be7ba1bde8f727534796701b..960f949b8f8f4e67441db808de694317de146002 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -17,6 +17,7 @@
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <linux/hardirq.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -289,14 +290,16 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
        struct request_queue *q = rq->q;
        int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
        unsigned int data_len = bufflen, len, bytes, off;
+       struct scatterlist *sg;
        struct page *page;
        struct bio *bio = NULL;
        int i, err, nr_vecs = 0;
 
-       for (i = 0; i < nsegs; i++) {
-               page = sgl[i].page;
-               off = sgl[i].offset;
-               len = sgl[i].length;
+       for_each_sg(sgl, sg, nsegs, i) {
+               page = sg->page;
+               off = sg->offset;
+               len = sg->length;
+               data_len += len;
 
                while (len > 0 && data_len > 0) {
                        /*
@@ -2193,18 +2196,19 @@ EXPORT_SYMBOL_GPL(scsi_target_unblock);
  *
  * Returns virtual address of the start of the mapped page
  */
-void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
                          size_t *offset, size_t *len)
 {
        int i;
        size_t sg_len = 0, len_complete = 0;
+       struct scatterlist *sg;
        struct page *page;
 
        WARN_ON(!irqs_disabled());
 
-       for (i = 0; i < sg_count; i++) {
+       for_each_sg(sgl, sg, sg_count, i) {
                len_complete = sg_len; /* Complete sg-entries */
-               sg_len += sg[i].length;
+               sg_len += sg->length;
                if (sg_len > *offset)
                        break;
        }
@@ -2218,10 +2222,10 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
        }
 
        /* Offset starting from the beginning of first page in this sg-entry */
-       *offset = *offset - len_complete + sg[i].offset;
+       *offset = *offset - len_complete + sg->offset;
 
        /* Assumption: contiguous pages can be accessed as "page + i" */
-       page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+       page = nth_page(sg->page, (*offset >> PAGE_SHIFT));
        *offset &= ~PAGE_MASK;
 
        /* Bytes in this sg-entry from *offset to the end of the page */

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 65ab5145a09befcc23a78de1090676d7f8fdd42e..3b0bb6680e625ed1641d0469aa07c0d9a21f66ad 100644 (file)
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/types.h>
 #include <linux/timer.h>
+#include <linux/scatterlist.h>
 
 struct request;
 struct scatterlist;
@@ -148,6 +149,6 @@ static inline int scsi_get_resid(struct scsi_cmnd *cmd)
 }
 
 #define scsi_for_each_sg(cmd, sg, nseg, __i)                   \
-       for (__i = 0, sg = scsi_sglist(cmd); __i < (nseg); __i++, (sg)++)
+       for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 
 #endif /* _SCSI_SCSI_CMND_H */