xen-blkfront: remove frame list from blk_shadow

We already have the frame (pfn of the grant page) stored inside struct
grant, so there's no need to keep an aditional list of mapped frames
for a specific request. This reduces memory usage in blkfront.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 1 insertions, 5 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index c64043323399..a894f88762d8 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -74,7 +74,6 @@ struct grant {
 struct blk_shadow {
         struct blkif_request req;
         struct request *request;
-        unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
         struct grant *grants_used[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 };
 
@@ -356,7 +355,6 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
 static int blkif_queue_request(struct request *req)
 {
         struct blkfront_info *info = req->rq_disk->private_data;
-        unsigned long buffer_mfn;
         struct blkif_request *ring_req;
         unsigned long id;
         unsigned int fsect, lsect;
@@ -434,7 +432,6 @@ static int blkif_queue_request(struct request *req)
 
                         gnt_list_entry = get_grant(&gref_head, info);
                         ref = gnt_list_entry->gref;
-                        buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn);
 
                         info->shadow[id].grants_used[i] = gnt_list_entry;
 
@@ -465,7 +462,6 @@ static int blkif_queue_request(struct request *req)
                                 kunmap_atomic(shared_data);
                         }
 
-                        info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
                         ring_req->u.rw.seg[i] =
                                         (struct blkif_request_segment) {
                                                 .gref       = ref,
@@ -1268,7 +1264,7 @@ static int blkif_recover(struct blkfront_info *info)
                                 gnttab_grant_foreign_access_ref(
                                         req->u.rw.seg[j].gref,
                                         info->xbdev->otherend_id,
-                                        pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]),
+                                        pfn_to_mfn(copy[i].grants_used[j]->pfn),
                                         0);
                 }
                 info->shadow[req->u.rw.id].req = *req;