Revert "net: rtnetlink: remove local list in __linkwatch_run_queue()"

This reverts commit b8dbbbc535 ("net: rtnetlink: remove local list
in __linkwatch_run_queue()"). It's evidently broken when there's a
non-urgent work that gets added back, and then the loop can never
finish.

While reverting, add a note about that.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: b8dbbbc535 ("net: rtnetlink: remove local list in __linkwatch_run_queue()")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Johannes Berg 2023-12-08 10:52:15 +01:00 committed by David S. Miller
parent 18c5c0a845
commit 9a64d4c93e

View File

@ -192,6 +192,11 @@ static void __linkwatch_run_queue(int urgent_only)
#define MAX_DO_DEV_PER_LOOP 100
int do_dev = MAX_DO_DEV_PER_LOOP;
/* Use a local list here since we add non-urgent
* events back to the global one when called with
* urgent_only=1.
*/
LIST_HEAD(wrk);
/* Give urgent case more budget */
if (urgent_only)
@ -213,11 +218,12 @@ static void __linkwatch_run_queue(int urgent_only)
clear_bit(LW_URGENT, &linkwatch_flags);
spin_lock_irq(&lweventlist_lock);
while (!list_empty(&lweventlist) && do_dev > 0) {
list_splice_init(&lweventlist, &wrk);
while (!list_empty(&wrk) && do_dev > 0) {
struct net_device *dev;
dev = list_first_entry(&lweventlist, struct net_device,
link_watch_list);
dev = list_first_entry(&wrk, struct net_device, link_watch_list);
list_del_init(&dev->link_watch_list);
if (!netif_device_present(dev) ||
@ -235,6 +241,9 @@ static void __linkwatch_run_queue(int urgent_only)
spin_lock_irq(&lweventlist_lock);
}
/* Add the remaining work back to lweventlist */
list_splice_init(&wrk, &lweventlist);
if (!list_empty(&lweventlist))
linkwatch_schedule_work(0);
spin_unlock_irq(&lweventlist_lock);