cluster/afr: Allow data/entry self heal for metadata split-brain

Problem:
Currently whenever there is metadata split-brain, a variable
sh->op_failed is set to 1 to denote that self heal got failed.
But if we proceed for data self heal, even code-path of data
self heal also relies on the sh->op_failed variable. So if will
check for sh->op_failed variable and will eventually fails to
do data self heal. So needed a mechanism to allow data self heal
even if metadata is in split brain.

Fix:
Some data structure revamp is done in
http://review.gluster.com/#/c/5106/ fix and this patch is
based on the above fix. Now we can store which particular self-heal
got failed i.e GFID_OR_MISSING_ENTRY_SELF_HEAL, METADATA, DATA,
ENTRY. And we can do two types of self heal failure check.
1. Individual type check: We can check which among all four
   (Metadata, Data, Gfid or missing entry, entry self heal)
   got failed.

2. In afr_self_heal_completion_cbk, we need to make check
   based on the fact that if any specific self heal got failed treat
   the complete self heal as failure so that it will populate
   corresponding circular buffer of event history accordingly.

Change-Id: Icb91e513bcc752386fc8a78812405cfabe5cac2d
BUG: 977797
Signed-off-by: Venkatesh Somyajulu <vsomyaju@redhat.com>
Reviewed-on: http://review.gluster.org/5253
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

2 files changed, 134 insertions, 0 deletions

diff --git a/tests/bugs/bug-977797.t b/tests/bugs/bug-977797.t
new file mode 100755
index 00000000000..08cdbe8f119
--- /dev/null
+++ b/tests/bugs/bug-977797.t
@@ -0,0 +1,114 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+cleanup;
+
+## Start and create a volume
+TEST glusterd;
+TEST pidof glusterd;
+TEST $CLI volume info;
+
+TEST $CLI volume create $V0 replica 2 $H0:$B0/${V0}{1,2};
+
+## Verify volume is is created
+EXPECT "$V0" volinfo_field $V0 'Volume Name';
+EXPECT 'Created' volinfo_field $V0 'Status';
+
+## Start volume and verify
+TEST $CLI volume start $V0;
+EXPECT 'Started' volinfo_field $V0 'Status';
+
+TEST $CLI volume set $V0 self-heal-daemon off
+TEST $CLI volume set $V0 open-behind off
+TEST $CLI volume set $V0 quick-read off
+TEST $CLI volume set $V0 read-ahead off
+TEST $CLI volume set $V0 write-behind off
+TEST $CLI volume set $V0 io-cache off
+TEST $CLI volume set $V0 background-self-heal-count 0
+
+TEST glusterfs --volfile-id=/$V0 --volfile-server=$H0 $M0 --attribute-timeout=0 --entry-timeout=0
+
+
+TEST mkdir -p $M0/a
+TEST `echo "GLUSTERFS" > $M0/a/file`
+
+TEST kill_brick $V0 $H0 $B0/$V0"1"
+
+TEST chown root $M0/a
+TEST chown root $M0/a/file
+TEST `echo "GLUSTER-FILE-SYSTEM" > $M0/a/file`
+TEST mkdir $M0/a/b
+
+TEST $CLI volume start $V0 force
+EXPECT_WITHIN 20 "1" afr_child_up_status $V0 0;
+
+
+
+TEST kill_brick $V0 $H0 $B0/$V0"2"
+
+TEST chmod 757 $M0/a
+TEST chmod 757 $M0/a/file
+
+TEST $CLI volume start $V0 force
+EXPECT_WITHIN 20 "1" afr_child_up_status $V0 1;
+
+TEST ls   -l $M0/a/file
+
+b1c0dir=$(afr_get_specific_changelog_xattr $B0/$V0"1"/a \
+          trusted.afr.$V0-client-0 "entry")
+b1c1dir=$(afr_get_specific_changelog_xattr $B0/$V0"1"/a \
+          trusted.afr.$V0-client-1 "entry")
+b2c0dir=$(afr_get_specific_changelog_xattr \
+          $B0/$V0"2"/a trusted.afr.$V0-client-0 "entry")
+b2c1dir=$(afr_get_specific_changelog_xattr \
+          $B0/$V0"2"/a trusted.afr.$V0-client-1 "entry")
+
+
+b1c0f=$(afr_get_specific_changelog_xattr $B0/$V0"1"/a/file \
+        trusted.afr.$V0-client-0 "data")
+b1c1f=$(afr_get_specific_changelog_xattr $B0/$V0"1"/a/file \
+        trusted.afr.$V0-client-1 "data")
+b2c0f=$(afr_get_specific_changelog_xattr $B0/$V0"2"/a/file \
+        trusted.afr.$V0-client-0 "data")
+b2c1f=$(afr_get_specific_changelog_xattr $B0/$V0"2"/a/file \
+        trusted.afr.$V0-client-1 "data")
+
+EXPECT "00000000" echo $b1c0f
+EXPECT "00000000" echo $b1c1f
+EXPECT "00000000" echo $b2c0f
+EXPECT "00000000" echo $b2c1f
+
+EXPECT "00000000" echo $b1c0dir
+EXPECT "00000000" echo $b1c1dir
+EXPECT "00000000" echo $b2c0dir
+EXPECT "00000000" echo $b2c1dir
+
+contains() {
+    string="$1"
+    substring="$2"
+    var="-1"
+    if test "${string#*$substring}" != "$string"
+    then
+        var="0"    # $substring is in $string
+    else
+        var="1"    # $substring is not in $string
+    fi
+    echo $var
+}
+
+var1=$(cat $M0/a/file 2>&1)
+var2="Input/output error"
+
+
+EXPECT "0" contains "$var1" "$var2"
+
+## Finish up
+TEST $CLI volume stop $V0;
+EXPECT 'Stopped' volinfo_field $V0 'Status';
+
+TEST $CLI volume delete $V0;
+TEST ! $CLI volume info $V0;
+
+cleanup;
diff --git a/tests/volume.rc b/tests/volume.rc
index 5bb974e1f50..b358b108d9d 100644
--- a/tests/volume.rc
+++ b/tests/volume.rc
@@ -237,6 +237,26 @@ function dht_get_layout {
 	getfattr -d -e hex -n $my_xa $1 2> /dev/null | grep "$my_xa=" | cut -d= -f2
 }
 
+function afr_get_specific_changelog_xattr ()
+{
+        local path=$1
+        local key=$2
+        local type=$3
+        local specific_changelog=""
+
+        changelog_xattr=$(afr_get_changelog_xattr "$path" "$key")
+        if [ "$type" == "data" ]; then
+                specific_changelog=${changelog_xattr:2:8}
+        elif [ "$type" == "metadata" ]; then
+                specific_changelog=${changelog_xattr:10:8}
+        elif [ "$type" == "entry" ]; then
+                specific_changelog=${changelog_xattr:18:8}
+        else
+                specific_changlog="error"
+        fi
+
+        echo $specific_changelog
+}
 ##
  # query pathinfo xattr and extract POSIX pathname(s)
  ##