From a70a110f3155d2cabf7cb445e32f0ed2827585cf Mon Sep 17 00:00:00 2001 From: Jonathan Earl Brassow Date: Mon, 30 Aug 2010 18:37:42 +0000 Subject: [PATCH] This patch fixes an issue where cluster mirror write I/O can be opprobriously slow if created with '--nosync'. One of the ways cluster mirrors coordinate I/O and recovery amoung the different machines is by the use of the log function 'is_remote_recovering()' which lets nodes know if a region they wish to perform a write on is currently being recovered on another node. If the region is being recovered, the I/O is delayed. The 'is_remote_recovering' routine has been optimized to avoid the deluge of requests that would be issued to the userspace log server by maintaining a marker of how far the recovery has gotten. It can then immediately return 'not recovering' if the region being inquired about is less than this mark. Additionally, if the region of concern is greater than the mark, the function will limit the number of transmissions to userspace by assuming the region /is/ being recovered when skipping the transmission. This limits the amount of processing and updates the mark in 1/4 sec time steps. This patch fixes a problem where 'the mark' is not being updated because of faulty logic in the userspace log daemon. When '--nosync' is used to create a cluster mirror, the userspace log daemon never has a chance to update the mark in the normal way. The fix is to set the mark to "complete" if the mirror was created with the --nosync flag. --- WHATS_NEW | 1 + daemons/cmirrord/functions.c | 1 + 2 files changed, 2 insertions(+) diff --git a/WHATS_NEW b/WHATS_NEW index 21559d5f1..dd94cc68e 100644 --- a/WHATS_NEW +++ b/WHATS_NEW @@ -1,5 +1,6 @@ Version 2.02.74 - ================================== + Fix opprobriously slow I/O to cluster mirrors created with --nosync. Make poll_mirror_progress report PROGRESS_CHECK_FAILED if LV is not a mirror. Like mirrors, don't scan origins if ignore_suspended_devices() is set. Fix return type qualifier to avoid compiler warning. (2.02.69) diff --git a/daemons/cmirrord/functions.c b/daemons/cmirrord/functions.c index 36910b195..e5da75756 100644 --- a/daemons/cmirrord/functions.c +++ b/daemons/cmirrord/functions.c @@ -1268,6 +1268,7 @@ static int clog_get_resync_work(struct dm_ulog_request *rq, uint32_t originator) LOG_SPRINT(lc, "GET - SEQ#=%u, UUID=%s, nodeid = %u:: " "Resync work complete.", rq->seq, SHORT_UUID(lc->uuid), originator); + lc->sync_search = lc->region_count + 1; return 0; }