From: Alex Elder Date: Tue, 9 Oct 2012 03:37:30 +0000 (-0700) Subject: rbd: reset BACKOFF if unable to re-queue X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=588377d6199034c36d335e7df5818b731fea072c;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git rbd: reset BACKOFF if unable to re-queue If ceph_fault() is unable to queue work after a delay, it sets the BACKOFF connection flag so con_work() will attempt to do so. In con_work(), when BACKOFF is set, if queue_delayed_work() doesn't result in newly-queued work, it simply ignores this condition and proceeds as if no backoff delay were desired. There are two problems with this--one of which is a bug. The first problem is simply that the intended behavior is to back off, and if we aren't able queue the work item to run after a delay we're not doing that. The only reason queue_delayed_work() won't queue work is if the provided work item is already queued. In the messenger, this means that con_work() is already scheduled to be run again. So if we simply set the BACKOFF flag again when this occurs, we know the next con_work() call will again attempt to hold off activity on the connection until after the delay. The second problem--the bug--is a leak of a reference count. If queue_delayed_work() returns 0 in con_work(), con->ops->put() drops the connection reference held on entry to con_work(). However, processing is (was) allowed to continue, and at the end of the function a second con->ops->put() is called. This patch fixes both problems. Signed-off-by: Alex Elder Reviewed-by: Sage Weil --- diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 159aa8bef9e7..cad0d17ec45e 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2300,10 +2300,11 @@ restart: mutex_unlock(&con->mutex); return; } else { - con->ops->put(con); dout("con_work %p FAILED to back off %lu\n", con, con->delay); + set_bit(CON_FLAG_BACKOFF, &con->flags); } + goto done; } if (con->state == CON_STATE_STANDBY) {