Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux...

[karo-tx-linux.git] / drivers / block / xen-blkback / blkback.c

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index eaccc222a1dcc710dfcfc1b0c5748f19fd982ba9..dd5b2fed97e9ae2b7665f13ec3c42db6ee6fb462 100644 (file)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -164,7 +164,7 @@ static void make_response(struct xen_blkif *blkif, u64 id,
 
 #define foreach_grant_safe(pos, n, rbtree, node) \
        for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \
-            (n) = rb_next(&(pos)->node); \
+            (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL; \
             &(pos)->node != NULL; \
             (pos) = container_of(n, typeof(*(pos)), node), \
             (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL)
@@ -442,7 +442,7 @@ int xen_blkif_schedule(void *arg)
 }
 
 struct seg_buf {
-       unsigned long buf;
+       unsigned int offset;
        unsigned int nsec;
 };
 /*
@@ -621,30 +621,21 @@ static int xen_blkbk_map(struct blkif_request *req,
                                 * If this is a new persistent grant
                                 * save the handler
                                 */
-                               persistent_gnts[i]->handle = map[j].handle;
-                               persistent_gnts[i]->dev_bus_addr =
-                                       map[j++].dev_bus_addr;
+                               persistent_gnts[i]->handle = map[j++].handle;
                        }
                        pending_handle(pending_req, i) =
                                persistent_gnts[i]->handle;
 
                        if (ret)
                                continue;
-
-                       seg[i].buf = persistent_gnts[i]->dev_bus_addr |
-                               (req->u.rw.seg[i].first_sect << 9);
                } else {
-                       pending_handle(pending_req, i) = map[j].handle;
+                       pending_handle(pending_req, i) = map[j++].handle;
                        bitmap_set(pending_req->unmap_seg, i, 1);
 
-                       if (ret) {
-                               j++;
+                       if (ret)
                                continue;
-                       }
-
-                       seg[i].buf = map[j++].dev_bus_addr |
-                               (req->u.rw.seg[i].first_sect << 9);
                }
+               seg[i].offset = (req->u.rw.seg[i].first_sect << 9);
        }
        return ret;
 }
@@ -971,7 +962,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
                       (bio_add_page(bio,
                                     pages[i],
                                     seg[i].nsec << 9,
-                                    seg[i].buf & ~PAGE_MASK) == 0)) {
+                                    seg[i].offset) == 0)) {
 
                        bio = bio_alloc(GFP_KERNEL, nseg-i);
                        if (unlikely(bio == NULL))
@@ -1001,13 +992,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
                bio->bi_end_io  = end_block_io_op;
        }
 
-       /*
-        * We set it one so that the last submit_bio does not have to call
-        * atomic_inc.
-        */
        atomic_set(&pending_req->pendcnt, nbio);
-
-       /* Get a reference count for the disk queue and start sending I/O */
        blk_start_plug(&plug);
 
        for (i = 0; i < nbio; i++)
@@ -1035,6 +1020,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
  fail_put_bio:
        for (i = 0; i < nbio; i++)
                bio_put(biolist[i]);
+       atomic_set(&pending_req->pendcnt, 1);
        __end_block_io_op(pending_req, -EINVAL);
        msleep(1); /* back off a bit */
        return -EIO;