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>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Roger Pau Monne 2013-03-18 17:49:33 +01:00 committed by Konrad Rzeszutek Wilk
parent 29d0b218c8
commit 217fd5e709
1 changed files with 1 additions and 1 deletions

View File

@ -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)