From 9f78a1dc55745042ecaed019ad0fc58d9e80d85e Mon Sep 17 00:00:00 2001 From: Ravishankar N Date: Fri, 14 Oct 2016 16:09:08 +0530 Subject: [PATCH 102/141] afr: Take full locks in arbiter only for data transactions Patch in master: http://review.gluster.org/#/c/15641/ Patch in release-3.8: http://review.gluster.org/#/c/15647/ Patch in release-3.9: http://review.gluster.org/#/c/15648/ 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. Change-Id: If9ca04b7a27e42ddedf185c4c36689ab53b39d54 BUG: 1380276 Signed-off-by: Ravishankar N Reviewed-on: https://code.engineering.redhat.com/gerrit/87216 Reviewed-by: Pranith Kumar Karampuri Tested-by: Pranith Kumar Karampuri --- xlators/cluster/afr/src/afr-transaction.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c index 27be045..856ea6e 100644 --- a/xlators/cluster/afr/src/afr-transaction.c +++ b/xlators/cluster/afr/src/afr-transaction.c @@ -1900,7 +1900,8 @@ 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; -- 1.7.1