From 0cd21d981f469c3cdc57dcd84802ced1a9f34155 Mon Sep 17 00:00:00 2001 From: Ravishankar N Date: Fri, 14 Oct 2016 16:09:08 +0530 Subject: afr: Take full locks in arbiter only for data transactions Problem: Sharding exposed a bug in arbiter config. where `dd` throughput was extremely slow. Shard xlator was sending a fxattrop to update the file size immediately after a writev. Arbiter was incorrectly over-riding the LLONGMAX-1 start offset (for metadata domain locks) for this fxattrop, causing the inodelk to be taken on the data domain. And since the preceeding writev hadn't released the lock (afr does a 'lazy' unlock if write succeeds on all bricks), this degraded to a blocking lock causing extra lock/unlock calls and delays. Fix: Modify flock.l_len and flock.l_start to take full locks only for data transactions. > Reviewed-on: http://review.gluster.org/15641 > Smoke: Gluster Build System > NetBSD-regression: NetBSD Build System > CentOS-regression: Gluster Build System > Reviewed-by: Pranith Kumar Karampuri (cherry picked from commit 3a97486d7f9d0db51abcb13dcd3bc9db935e3a60) Change-Id: I906895da2f2d16813607e6c906cb4defb21d7c3b BUG: 1385224 Signed-off-by: Ravishankar N Reported-by: Max Raba Reviewed-on: http://review.gluster.org/15648 NetBSD-regression: NetBSD Build System Reviewed-by: Pranith Kumar Karampuri CentOS-regression: Gluster Build System Smoke: Gluster Build System --- xlators/cluster/afr/src/afr-transaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'xlators') diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c index db7c6dbd2b0..663e4034fb2 100644 --- a/xlators/cluster/afr/src/afr-transaction.c +++ b/xlators/cluster/afr/src/afr-transaction.c @@ -1901,7 +1901,8 @@ afr_set_transaction_flock (xlator_t *this, afr_local_t *local) inodelk = afr_get_inodelk (int_lock, int_lock->domain); priv = this->private; - if (priv->arbiter_count) { + if (priv->arbiter_count && + local->transaction.type == AFR_DATA_TRANSACTION) { /*Lock entire file to avoid network split brains.*/ inodelk->flock.l_len = 0; inodelk->flock.l_start = 0; -- cgit