afr: modify afr_txn_nothing_failed()

Backport of http://review.gluster.org/#/c/11827/

In an AFR transaction, we need to consider something as failed only if the
failure (either in the pre-op or the FOP phase) occurs on the bricks on which a
transaction lock was obtained.

Without this, we would end up considering the transaction as failure even on the
bricks on which the lock was not obtained, resulting in unnecessary fsyncs
during the post-op phase of every write transaction for non-appending writes.

Change-Id: Iee79e5d85dc7b4c41459d8bdd04a8454bdaf9a9d
BUG: 1255698
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/11985
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>

3 files changed, 94 insertions, 12 deletions

diff --git a/tests/bugs/replicate/bug-1250170-fsync.c b/tests/bugs/replicate/bug-1250170-fsync.c
new file mode 100644
index 00000000000..1d3025bcd9f
--- /dev/null
+++ b/tests/bugs/replicate/bug-1250170-fsync.c
@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+
+int main (int argc, char **argv)
+{
+        char *file = NULL;
+        int fd = -1;
+        char *buffer = NULL;
+        size_t buf_size = 0;
+        size_t written = 0;
+        int ret = 0;
+        off_t offset = 0;
+        int i = 0;
+        int loop_count = 5;
+
+        if (argc < 2) {
+                printf ("Usage:%s <filename>\n", argv[0]);
+                return -1;
+        }
+
+        file = argv[1];
+        buf_size = 1024;
+        buffer = calloc(1, buf_size);
+        if (!buffer) {
+                perror("calloc");
+                return -1;
+        }
+        memset (buffer, 'R', buf_size);
+
+        fd = open(file, O_WRONLY);
+        if (fd == -1) {
+                perror("open");
+                return -1;
+        }
+
+        for (i = 0; i < loop_count; i++) {
+                ret =  write (fd, buffer, buf_size);
+                if (ret == -1) {
+                        perror("write");
+                        return ret;
+                } else {
+                        written += ret;
+                }
+                offset = lseek (fd, 0 , SEEK_SET);
+        }
+
+        free(buffer);
+        return 0;
+
+}
diff --git a/tests/bugs/replicate/bug-1250170-fsync.t b/tests/bugs/replicate/bug-1250170-fsync.t
new file mode 100644
index 00000000000..7a3fdbf8bb5
--- /dev/null
+++ b/tests/bugs/replicate/bug-1250170-fsync.t
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup;
+TEST gcc  $(dirname $0)/bug-1250170-fsync.c -o  $(dirname $0)/bug-1250170-fsync
+TEST glusterd
+TEST pidof glusterd
+
+TEST $CLI volume create $V0 replica 2 $H0:$B0/${V0}{0,1}
+TEST $CLI volume set $V0 performance.write-behind off
+TEST $CLI volume start $V0
+TEST $GFS --volfile-id=$V0 --volfile-server=$H0 $M0;
+
+TEST touch $M0/file
+TEST kill_brick $V0 $H0 $B0/${V0}0
+TEST gluster volume profile $V0 start
+#Perform 5 non-sequential writes.
+TEST $(dirname $0)/bug-1250170-fsync $M0/file
+
+#Run profile info initially to filter out the interval statistics in the
+#subsequent runs.
+TEST $CLI volume profile $V0 info
+#We get only cumulative statistics.
+write_count=$($CLI volume profile $V0 info | grep WRITE |awk '{count += $8} END {print count}')
+fsync_count=$($CLI volume profile $V0 info | grep FSYNC |awk '{count += $8} END {print count}')
+
+EXPECT "5" echo $write_count
+TEST [ -z $fsync_count ]
+
+TEST $CLI volume profile $V0 stop
+TEST umount $M0
+rm -f $(dirname $0)/bug-1250170-fsync
+cleanup
diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index ba50abd6d38..d773b5ace7a 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -493,18 +493,14 @@ afr_txn_nothing_failed (call_frame_t *frame, xlator_t *this)
 {
         afr_private_t *priv = NULL;
         afr_local_t *local = NULL;
-        int pre_op_count = 0;
         int i = 0;
 
         local = frame->local;
 	priv = this->private;
 
-        pre_op_count = AFR_COUNT (local->transaction.pre_op, priv->child_count);
-        if (pre_op_count < priv->child_count)
-                return _gf_false;
-
         for (i = 0; i < priv->child_count; i++) {
-                if (local->transaction.failed_subvols[i])
+                if (local->transaction.pre_op[i] &&
+                    local->transaction.failed_subvols[i])
                         return _gf_false;
         }
 
@@ -1156,14 +1152,9 @@ afr_changelog_pre_op (call_frame_t *frame, xlator_t *this)
 		goto err;
 	}
 
-	if (call_count > 1 &&
-	    (local->transaction.type == AFR_DATA_TRANSACTION ||
+	if ((local->transaction.type == AFR_DATA_TRANSACTION ||
 	     !local->optimistic_change_log)) {
 
-		/* If we are performing change on only one subvol, no
-		   need to mark dirty, because we are setting the pending
-		   counts already anyways
-		*/
 		local->dirty[idx] = hton32(1);
 
 		ret = dict_set_static_bin (xdata_req, AFR_DIRTY, local->dirty,