ocfs2: make 'buffered' as the default coherency option

Orabug: 17988729

Customers upgrading to uek2 and above will see the default coherency option
set to 'full' which impacts -ve performance. This patch changes coherence
option to buffered which keeps the default behaviour same as old(UEK1).
If an application that does direct i/o needs cache coherency then they can
use mount option 'coherency=full'

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Acked-by: Srinivas Eeda <srinivas.eeda@oracle.com>
(cherry picked from commit 020a20029508d2d7f36470bebd23f053de4b0dbe)

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 403c5660b30644a5c6f564ccaf795af4749e659a..f342d1a99a60926fe81a7c435482571e0595fa5e 100644 (file)
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1283,6 +1283,13 @@ static int ocfs2_parse_options(struct super_block *sb,
 
        mopt->commit_interval = 0;
        mopt->mount_opt = OCFS2_MOUNT_NOINTR;
+
+       /*
+        * Make 'buffered' as default coherency option. This is to keep the
+        * default behaviour unchanged(same as in UEK1)
+        */
+       mopt->mount_opt |= OCFS2_MOUNT_COHERENCY_BUFFERED;
+
        mopt->atime_quantum = OCFS2_DEFAULT_ATIME_QUANTUM;
        mopt->slot = OCFS2_INVALID_SLOT;
        mopt->localalloc_opt = -1;