We may use foreach_grant_safe in the future with empty lists, so make
sure we can handle them.

Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Cc: xen-de...@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
---
 drivers/block/xen-blkback/blkback.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c 
b/drivers/block/xen-blkback/blkback.c
index d40beb3..415a0c7 100644
--- 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)
-- 
1.7.7.5 (Apple Git-26)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to