features/shard: Fix shard inode refcount when it's part of priv->lru_list.

For as long as a shard's inode is in priv->lru_list, it should have a non-zero
ref-count. This patch achieves it by taking a ref on the inode when it
is added to lru list. When it's time for the inode to be evicted
from the lru list, a corresponding unref is done.

Change-Id: I289ffb41e7be5df7489c989bc1bbf53377433c86
BUG: 1468483
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>

3 files changed, 45 insertions, 17 deletions

diff --git a/tests/basic/inode-leak.t b/tests/basic/inode-leak.t
index f73d2af6898..6bfbf572f03 100644
--- a/tests/basic/inode-leak.t
+++ b/tests/basic/inode-leak.t
@@ -3,23 +3,6 @@
 . $(dirname $0)/../include.rc
 . $(dirname $0)/../volume.rc
 
-function get_mount_active_size_value {
-        local vol=$1
-        local statedump=$(generate_mount_statedump $vol)
-        sleep 1
-        local val=$(grep "active_size" $statedump | cut -f2 -d'=' | tail -1)
-        rm -f $statedump
-        echo $val
-}
-
-function get_mount_lru_size_value {
-        local vol=$1
-        local statedump=$(generate_mount_statedump $vol)
-        sleep 1
-        local val=$(grep "lru_size" $statedump | cut -f2 -d'=' | tail -1)
-        rm -f $statedump
-        echo $val
-}
 cleanup
 
 TEST glusterd
diff --git a/tests/bugs/shard/shard-inode-refcount-test.t b/tests/bugs/shard/shard-inode-refcount-test.t
new file mode 100644
index 00000000000..635809724cf
--- /dev/null
+++ b/tests/bugs/shard/shard-inode-refcount-test.t
@@ -0,0 +1,27 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 $H0:$B0/${V0}0
+TEST $CLI volume set $V0 features.shard on
+TEST $CLI volume set $V0 features.shard-block-size 4MB
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 $M0
+
+TEST dd if=/dev/zero of=$M0/one-plus-five-shards bs=1M count=23
+
+ACTIVE_INODES_BEFORE=$(get_mount_active_size_value $V0)
+TEST rm -f $M0/one-plus-five-shards
+EXPECT `expr $ACTIVE_INODES_BEFORE - 5` get_mount_active_size_value $V0
+
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+cleanup
diff --git a/tests/volume.rc b/tests/volume.rc
index 3ee83624058..add812d4779 100644
--- a/tests/volume.rc
+++ b/tests/volume.rc
@@ -812,3 +812,21 @@ function get_fd_count {
         rm -f $statedump
         echo $count
 }
+
+function get_mount_active_size_value {
+        local vol=$1
+        local statedump=$(generate_mount_statedump $vol)
+        sleep 1
+        local val=$(grep "active_size" $statedump | cut -f2 -d'=' | tail -1)
+        rm -f $statedump
+        echo $val
+}
+
+function get_mount_lru_size_value {
+        local vol=$1
+        local statedump=$(generate_mount_statedump $vol)
+        sleep 1
+        local val=$(grep "lru_size" $statedump | cut -f2 -d'=' | tail -1)
+        rm -f $statedump
+        echo $val
+}