Roger Pau Monne
2013-Feb-28 10:28 UTC
[PATCH RFC 02/12] xen-blkback: fix foreach_grant_safe to handle empty lists
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.pau@citrix.com> Cc: xen-devel@lists.xen.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@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) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel