From c424d672103287c016f76b3129e46ad9ea085f61 Mon Sep 17 00:00:00 2001
From: Pranith Kumar K <pkarampu@redhat.com>
Date: Wed, 24 Aug 2016 21:01:05 +0530
Subject: [PATCH 100/141] cluster/ec: Use locks for opendir

Problem:
In some cases we see that readdir keeps winding to the brick that doesn't have
any blocked locks i.e. first brick. This is leading to the client assuming that
there are no blocking locks on the inode so it won't give away the lock. Other
clients end up blocked on the lock as if the command hung.

Fix:
Proper way to fix this issue is to use infra present in
http://review.gluster.org/14736 This is a stop gap fix where we start taking
inodelks in opendir which goes to all the bricks, this will detect if there is
any contention.

cherry picked from commit f013335400d033a9677797377b90b968803135f4:
>BUG: 1346719
>Change-Id: I91109107a26f6535b945ac476338e9f21dc31eb9
>Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
>Reviewed-on: http://review.gluster.org/15309
>Smoke: Gluster Build System <jenkins@build.gluster.org>
>CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
>NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
>Reviewed-by: Ashish Pandey <aspandey@redhat.com>
>Signed-off-by: Ashish Pandey <aspandey@redhat.com>

Change-Id: I91109107a26f6535b945ac476338e9f21dc31eb9
BUG: 1361519
Signed-off-by: Ashish Pandey <aspandey@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/87175
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
---
 xlators/cluster/ec/src/ec-dir-read.c |   22 +++++++++++++++++++++-
 1 files changed, 21 insertions(+), 1 deletions(-)

diff --git a/xlators/cluster/ec/src/ec-dir-read.c b/xlators/cluster/ec/src/ec-dir-read.c
index fc8b38b..ed53a04 100644
--- a/xlators/cluster/ec/src/ec-dir-read.c
+++ b/xlators/cluster/ec/src/ec-dir-read.c
@@ -138,6 +138,13 @@ int32_t ec_manager_opendir(ec_fop_data_t * fop, int32_t state)
             UNLOCK(&fop->fd->lock);
 
             /* Fall through */
+
+        case EC_STATE_LOCK:
+            ec_lock_prepare_inode(fop, &fop->loc[0], EC_QUERY_INFO);
+            ec_lock(fop);
+
+            return EC_STATE_DISPATCH;
+
         case EC_STATE_DISPATCH:
             ec_dispatch_all(fop);
 
@@ -173,9 +180,10 @@ int32_t ec_manager_opendir(ec_fop_data_t * fop, int32_t state)
                                   cbk->op_errno, cbk->fd, cbk->xdata);
             }
 
-            return EC_STATE_END;
+            return EC_STATE_LOCK_REUSE;
 
         case -EC_STATE_INIT:
+        case -EC_STATE_LOCK:
         case -EC_STATE_DISPATCH:
         case -EC_STATE_PREPARE_ANSWER:
         case -EC_STATE_REPORT:
@@ -187,6 +195,18 @@ int32_t ec_manager_opendir(ec_fop_data_t * fop, int32_t state)
                                   NULL, NULL);
             }
 
+            return EC_STATE_LOCK_REUSE;
+
+        case -EC_STATE_LOCK_REUSE:
+        case EC_STATE_LOCK_REUSE:
+            ec_lock_reuse(fop);
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_UNLOCK:
+        case EC_STATE_UNLOCK:
+            ec_unlock(fop);
+
             return EC_STATE_END;
 
         default:
-- 
1.7.1