[PATCH v2 RESEND] xenbus: prefer list_for_each()

From: Jan Beulich
Date: Mon Oct 24 2016 - 11:04:02 EST


This is more efficient than list_for_each_safe() when list modification
is accompanied by breaking out of the loop.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
---
v2: Avoid commit message to continue from subject.
---
drivers/xen/xenbus/xenbus_dev_frontend.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 4.9-rc2/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ 4.9-rc2-xenbus-dev-list_for_each/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -364,7 +364,7 @@ out:

static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
{
- struct watch_adapter *watch, *tmp_watch;
+ struct watch_adapter *watch;
char *path, *token;
int err, rc;
LIST_HEAD(staging_q);
@@ -399,7 +399,7 @@ static int xenbus_write_watch(unsigned m
}
list_add(&watch->list, &u->watches);
} else {
- list_for_each_entry_safe(watch, tmp_watch, &u->watches, list) {
+ list_for_each_entry(watch, &u->watches, list) {
if (!strcmp(watch->token, token) &&
!strcmp(watch->watch.node, path)) {
unregister_xenbus_watch(&watch->watch);