cluster/afr: Provide an option to disable afr durability

Change-Id: I40eec20ca6b3f857245a2438883822e251077ee9
BUG: 979365
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/5269
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

4 files changed, 28 insertions, 3 deletions

diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index dbc74ceba53..d307d5b3eee 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -1495,8 +1495,10 @@ int
 afr_changelog_post_op_safe (call_frame_t *frame, xlator_t *this)
 {
 	afr_local_t    *local = NULL;
+        afr_private_t  *priv = NULL;
 
 	local = frame->local;
+        priv = this->private;
 
 	if (!local->fd || local->transaction.type != AFR_DATA_TRANSACTION) {
 		afr_changelog_post_op_now (frame, this);
@@ -1548,9 +1550,15 @@ afr_changelog_post_op_safe (call_frame_t *frame, xlator_t *this)
 		return 0;
 	}
 
-	/* Time to fsync() */
-
-	afr_changelog_fsync (frame, this);
+        /* Check whether users want durability and perform fsync/post-op
+         * accordingly.
+         */
+        if (priv->ensure_durability) {
+                /* Time to fsync() */
+                afr_changelog_fsync (frame, this);
+        } else {
+                afr_changelog_post_op_now (frame, this);
+        }
 
 	return 0;
 }
diff --git a/xlators/cluster/afr/src/afr.c b/xlators/cluster/afr/src/afr.c
index 6fabc00171f..9a13fbdacd9 100644
--- a/xlators/cluster/afr/src/afr.c
+++ b/xlators/cluster/afr/src/afr.c
@@ -191,6 +191,8 @@ reconfigure (xlator_t *this, dict_t *options)
         /* Reset this so we re-discover in case the topology changed.  */
         GF_OPTION_RECONF ("readdir-failover", priv->readdir_failover, options,
                           bool, out);
+        GF_OPTION_RECONF ("ensure-durability", priv->ensure_durability, options,
+                          bool, out);
         priv->did_discovery = _gf_false;
 
         ret = 0;
@@ -335,6 +337,8 @@ init (xlator_t *this)
 
 	GF_OPTION_INIT ("post-op-delay-secs", priv->post_op_delay_secs, uint32, out);
         GF_OPTION_INIT ("readdir-failover", priv->readdir_failover, bool, out);
+        GF_OPTION_INIT ("ensure-durability", priv->ensure_durability, bool,
+                        out);
 
         priv->wait_count = 1;
 
@@ -767,5 +771,12 @@ struct volume_options options[] = {
           .description = "readdir(p) will not failover if this option is off",
           .default_value = "on",
         },
+        { .key = {"ensure-durability"},
+          .type = GF_OPTION_TYPE_BOOL,
+          .description = "Afr performs fsyncs for transactions if this "
+                         "option is on to make sure the changelogs/data is "
+                         "written to the disk",
+          .default_value = "on",
+        },
         { .key  = {NULL} },
 };
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 836a64d0a1f..e72398a62bc 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -170,6 +170,7 @@ typedef struct _afr_private {
         gf_boolean_t           did_discovery;
         gf_boolean_t           readdir_failover;
         uint64_t               sh_readdir_size;
+        gf_boolean_t           ensure_durability;
 } afr_private_t;
 
 typedef enum {
diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-set.c b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
index 6c4af6e3e61..f57f49f42e9 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-set.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
@@ -524,6 +524,11 @@ struct volopt_map_entry glusterd_volopt_map[] = {
           .op_version = 2,
           .flags      = OPT_FLAG_CLIENT_OPT
         },
+        { .key        = "cluster.ensure-durability",
+          .voltype    = "cluster/replicate",
+          .op_version = 2,
+          .flags      = OPT_FLAG_CLIENT_OPT
+        },
 
         /* Stripe xlator options */
         { .key         = "cluster.stripe-block-size",