features/changelog : Improvement in changelog "encoding-change".

change in encoding method of changelog was critical section for
"fop dispatch thread", "roll-over thread" and "reconfigure dispatch thread".

In this patch the "encoding-method" is changed by the reconfigure dispatch thread
lazily during handle_change, which solves the concurrency among the racing
threads.

BUG: 1002940
Change-Id: I78c3e8887efa46d0fcc60755cdf4243031cfa3eb
Signed-off-by: Ajeet Jha <ajha@redhat.com>
Reviewed-on: http://review.gluster.org/5844
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/xlators/features/changelog/src/changelog-encoders.c b/xlators/features/changelog/src/changelog-encoders.c
index c71ea9270b0..553eec85c30 100644
--- a/xlators/features/changelog/src/changelog-encoders.c
+++ b/xlators/features/changelog/src/changelog-encoders.c
@@ -154,3 +154,23 @@ changelog_encode_binary (xlator_t *this, changelog_log_data_t *cld)
 
         return changelog_write_change (priv, buffer, off);
 }
+
+static struct changelog_encoder
+cb_encoder[] = {
+        [CHANGELOG_ENCODE_BINARY] =
+        {
+                .encoder = CHANGELOG_ENCODE_BINARY,
+                .encode = changelog_encode_binary,
+        },
+        [CHANGELOG_ENCODE_ASCII] =
+        {
+                .encoder = CHANGELOG_ENCODE_ASCII,
+                .encode = changelog_encode_ascii,
+        },
+};
+
+void
+changelog_encode_change( changelog_priv_t * priv)
+{
+        priv->ce = &cb_encoder[priv->encode_mode];
+}