cluster/afr: Perform delayed changelog wakeups for anon fd

Problem:
Nfs xlator never does open on a file for performing writes,
afr does not perform changelog wakeup for this fd so operations
which do metadata operations as soon as the data operations are
completed perceive a delay of 'post-op-delay-secs'.

Fix:
Perform changelog wakeup on anon-fd if the fd with same pid is
not present in inode-list.

Note:
This approach is a short-term fix. A proper fix needs a new domain
for taking metadata locks so that data/metadata locks don't compete
with each other.

Change-Id: I253afb289eadf30c7951e56fb2c4840d7132f5e4
BUG: 966018
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/5066
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

4 files changed, 56 insertions, 0 deletions

diff --git a/libglusterfs/src/fd.c b/libglusterfs/src/fd.c
index 2f4afc5e87a..36cc4d0561f 100644
--- a/libglusterfs/src/fd.c
+++ b/libglusterfs/src/fd.c
@@ -780,6 +780,23 @@ fd_anonymous (inode_t *inode)
         return fd;
 }
 
+fd_t*
+fd_lookup_anonymous (inode_t *inode)
+{
+        fd_t *fd = NULL;
+
+        if (!inode) {
+                gf_log_callingfn ("fd", GF_LOG_WARNING, "!inode");
+                return NULL;
+        }
+
+        LOCK (&inode->lock);
+        {
+                fd = __fd_lookup_anonymous (inode);
+        }
+        UNLOCK (&inode->lock);
+        return fd;
+}
 
 gf_boolean_t
 fd_is_anonymous (fd_t *fd)
diff --git a/libglusterfs/src/fd.h b/libglusterfs/src/fd.h
index 54290b1980b..c1b9157d882 100644
--- a/libglusterfs/src/fd.h
+++ b/libglusterfs/src/fd.h
@@ -134,6 +134,9 @@ fd_lookup (struct _inode *inode, pid_t pid);
 fd_t *
 fd_lookup_uint64 (struct _inode *inode, uint64_t pid);
 
+fd_t*
+fd_lookup_anonymous (inode_t *inode);
+
 fd_t *
 fd_anonymous (inode_t *inode);
 
diff --git a/tests/bugs/bug-966018.t b/tests/bugs/bug-966018.t
new file mode 100644
index 00000000000..f29690a1a03
--- /dev/null
+++ b/tests/bugs/bug-966018.t
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+#This tests if eager-lock blocks metadata operations on nfs/fuse mounts.
+#If it is not woken up, INODELK from the next command waits
+#for post-op-delay secs.
+
+cleanup;
+TEST glusterd
+TEST pidof glusterd
+
+TEST $CLI volume create $V0 replica 2 $H0:$B0/r2_0 $H0:$B0/r2_1
+TEST $CLI volume set $V0 cluster.eager-lock on
+TEST $CLI volume set $V0 cluster.post-op-delay-secs 3
+
+TEST $CLI volume start $V0
+TEST $CLI volume profile $V0 start
+sleep 5
+TEST mount -t nfs -o vers=3,nolock $H0:/$V0 $N0;
+TEST glusterfs --entry-timeout=0 --attribute-timeout=0 -s $H0 --volfile-id=$V0 $M0
+echo 1 > $N0/1 && chmod +x $N0/1
+echo 1 > $M0/1 && chmod +x $M0/1
+
+#Check that INODELK MAX latency is not in the order of seconds
+#Test if the MAX INODELK fop latency is of the order of seconds.
+inodelk_max_latency=$($CLI volume profile $V0 info | grep INODELK | awk 'BEGIN {max = 0} {if ($6 > max) max=$6;} END {print max}' | cut -d. -f 1 | egrep "[0-9]{7,}")
+
+TEST [ -z $inodelk_max_latency ]
+TEST umount $N0
+
+cleanup;
diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index 217ff854852..2bfd5daca4a 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -1802,6 +1802,9 @@ afr_transaction (call_frame_t *frame, xlator_t *this, afr_transaction_type type)
 
         if (!local->transaction.eager_lock_on && local->loc.inode) {
                 fd = fd_lookup (local->loc.inode, frame->root->pid);
+                if (fd == NULL)
+                        fd = fd_lookup_anonymous (local->loc.inode);
+
                 if (fd) {
                         afr_delayed_changelog_wake_up (this, fd);
                         fd_unref (fd);