[Xen-changelog] [linux-2.6.18-xen] linux/blkfront: use blk_rq_map_sg to generate ring entries

["Xen patchbot-linux-2.6.18-xen" <patchbot-linux-2.6.18-xen@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1236264120 0
# Node ID 63be3e5e2f1a132ce062c446a7d742e3523cf16b
# Parent  f3de83c4677ff77eaf445b3182f00169f6982ce3
linux/blkfront: use blk_rq_map_sg to generate ring entries

Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
 drivers/xen/blkfront/blkfront.c |   33 ++++++++++++++-------------------
 drivers/xen/blkfront/block.h    |    1 +
 2 files changed, 15 insertions(+), 19 deletions(-)

diff -r f3de83c4677f -r 63be3e5e2f1a drivers/xen/blkfront/blkfront.c
--- a/drivers/xen/blkfront/blkfront.c   Thu Mar 05 14:40:35 2009 +0000
+++ b/drivers/xen/blkfront/blkfront.c   Thu Mar 05 14:42:00 2009 +0000
@@ -40,6 +40,7 @@
 #include <linux/cdrom.h>
 #include <linux/sched.h>
 #include <linux/interrupt.h>
+#include <linux/scatterlist.h>
 #include <scsi/scsi.h>
 #include <xen/evtchn.h>
 #include <xen/xenbus.h>
@@ -231,6 +232,8 @@ static int setup_blkring(struct xenbus_d
        }
        SHARED_RING_INIT(sring);
        FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+
+       sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
 
        err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
        if (err < 0) {
@@ -587,13 +590,11 @@ static int blkif_queue_request(struct re
        struct blkfront_info *info = req->rq_disk->private_data;
        unsigned long buffer_mfn;
        blkif_request_t *ring_req;
-       struct bio *bio;
-       struct bio_vec *bvec;
-       int idx;
        unsigned long id;
        unsigned int fsect, lsect;
-       int ref;
+       int i, ref;
        grant_ref_t gref_head;
+       struct scatterlist *sg;
 
        if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
                return 1;
@@ -622,14 +623,13 @@ static int blkif_queue_request(struct re
        if (blk_barrier_rq(req))
                ring_req->operation = BLKIF_OP_WRITE_BARRIER;
 
-       ring_req->nr_segments = 0;
-       rq_for_each_bio (bio, req) {
-               bio_for_each_segment (bvec, bio, idx) {
-                       BUG_ON(ring_req->nr_segments
-                              == BLKIF_MAX_SEGMENTS_PER_REQUEST);
-                       buffer_mfn = page_to_phys(bvec->bv_page) >> PAGE_SHIFT;
-                       fsect = bvec->bv_offset >> 9;
-                       lsect = fsect + (bvec->bv_len >> 9) - 1;
+       ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg);
+       BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
+       for (i = 0; i < ring_req->nr_segments; ++i) {
+                       sg = info->sg + i;
+                       buffer_mfn = page_to_phys(sg->page) >> PAGE_SHIFT;
+                       fsect = sg->offset >> 9;
+                       lsect = fsect + (sg->length >> 9) - 1;
                        /* install a grant reference. */
                        ref = gnttab_claim_grant_reference(&gref_head);
                        BUG_ON(ref == -ENOSPC);
@@ -640,17 +640,12 @@ static int blkif_queue_request(struct re
                                buffer_mfn,
                                rq_data_dir(req) ? GTF_readonly : 0 );
 
-                       info->shadow[id].frame[ring_req->nr_segments] =
-                               mfn_to_pfn(buffer_mfn);
-
-                       ring_req->seg[ring_req->nr_segments] =
+                       info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
+                       ring_req->seg[i] =
                                (struct blkif_request_segment) {
                                        .gref       = ref,
                                        .first_sect = fsect,
                                        .last_sect  = lsect };
-
-                       ring_req->nr_segments++;
-               }
        }
 
        info->ring.req_prod_pvt++;
diff -r f3de83c4677f -r 63be3e5e2f1a drivers/xen/blkfront/block.h
--- a/drivers/xen/blkfront/block.h      Thu Mar 05 14:40:35 2009 +0000
+++ b/drivers/xen/blkfront/block.h      Thu Mar 05 14:42:00 2009 +0000
@@ -103,6 +103,7 @@ struct blkfront_info
        int connected;
        int ring_ref;
        blkif_front_ring_t ring;
+       struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
        unsigned int irq;
        struct xlbd_major_info *mi;
        request_queue_t *rq;

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog