From d08f81216085cda58a64f51872b4d2497958a7ea Mon Sep 17 00:00:00 2001
From: Pranith Kumar K <pkarampu@redhat.com>
Date: Fri, 6 Jul 2018 12:28:53 +0530
Subject: [PATCH 314/325] cluster/afr: Prevent execution of code after
 call_count decrementing

      Upstream-patch: https://review.gluster.org/20470

Problem:
When call_count is decremented by one thread, another thread can
go ahead with the operation leading to undefined behavior for the
thread executing statements after decrementing call count.

Fix:
Do the operations necessary before decrementing call count.

 >fixes bz#1598663
BUG: 1598105
Change-Id: Icc90cd92ac16e5fbdfe534d9f0a61312943393fe
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/143624
Tested-by: RHGS Build Bot <nigelb@redhat.com>
Reviewed-by: Sunil Kumar Heggodu Gopala Acharya <sheggodu@redhat.com>
---
 xlators/cluster/afr/src/afr-lk-common.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/xlators/cluster/afr/src/afr-lk-common.c b/xlators/cluster/afr/src/afr-lk-common.c
index be3de01..dff6644 100644
--- a/xlators/cluster/afr/src/afr-lk-common.c
+++ b/xlators/cluster/afr/src/afr-lk-common.c
@@ -970,6 +970,14 @@ afr_nonblocking_inodelk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         local    = frame->local;
         int_lock = &local->internal_lock;
 
+        if (op_ret == 0 && local->transaction.type == AFR_DATA_TRANSACTION) {
+                LOCK (&local->inode->lock);
+                {
+                        local->inode_ctx->lock_count++;
+                }
+                UNLOCK (&local->inode->lock);
+        }
+
         LOCK (&frame->lock);
         {
 		if (op_ret < 0) {
@@ -994,13 +1002,6 @@ afr_nonblocking_inodelk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         }
         UNLOCK (&frame->lock);
 
-        if (op_ret == 0 && local->transaction.type == AFR_DATA_TRANSACTION) {
-                LOCK (&local->inode->lock);
-                {
-                        local->inode_ctx->lock_count++;
-                }
-                UNLOCK (&local->inode->lock);
-        }
         if (call_count == 0) {
                 gf_msg_trace (this->name, 0,
                               "Last inode locking reply received");
-- 
1.8.3.1