tier/ctr: Providing option to record or ignore metadata heat

Currently we heat up a file for both data and metadata write.
Here we provide a ctr xlator option called "ctr-record-metadata-heat"
were the admin can decide on recording metadata heat i.e heatup a
file on metadata writes or not.
Metadata data operation are
a. setattr: explicit changing of atime/mtime using utimes,
            changing of posix permissions of the file
b. rename: Renaming a file,
c. unlink, link: adding or deleting hardlinks
d. xattrs: setting or removal of xattrs.

NOTE: atime, mtime and ctime change through writev, readv, truncate, mknod
and create will not be considered here as these fops are data and primary
metadata fops.

Defaultly "ctr-record-metadata-heat" is off. Admin can
switch it on using gluster volume set command.

Backport of http://review.gluster.org/12540

> Change-Id: I91157509255dd5cb429cda2b6d4f64582e155e7b
> BUG: 1279166
> Signed-off-by: Joseph Fernandes <josferna@redhat.com>
> Reviewed-on: http://review.gluster.org/12540
> Tested-by: NetBSD Build System <jenkins@build.gluster.org>
> Tested-by: Gluster Build System <jenkins@build.gluster.com>
> Reviewed-by: Dan Lambright <dlambrig@redhat.com>
> Tested-by: Dan Lambright <dlambrig@redhat.com>
Signed-off-by: Joseph Fernandes <josferna@redhat.com>

Change-Id: I986c319f0cc337b0692a1dd02f71254e786afac4
BUG: 1282315
Reviewed-on: http://review.gluster.org/12582
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-set.c b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
index b942d9df944..e17a43dc835 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-set.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
@@ -2071,6 +2071,22 @@ struct volopt_map_entry glusterd_volopt_map[] = {
                          "of writes (or reads) to a given file are needed "
                          "before triggering migration."
         },
+        { .key         = "features.ctr-record-metadata-heat",
+          .voltype     = "features/changetimerecorder",
+          .value       = "off",
+          .option      = "ctr-record-metadata-heat",
+          .op_version  = GD_OP_VERSION_3_7_0,
+          /* Purposefully commenting the description so that this option remains
+           * hidden from the users as this is more of a developer option as of
+           * now.
+           * .description = "Its a Change Time Recorder Xlator option to "
+           *             "enable recording write heat on metadata of the file. "
+                         "The default is disabled. "
+                         "Metadata is inode atttributes like atime, mtime,"
+                         " permissions etc and "
+                         "extended attributes of a file ."
+           * */
+        },
         { .key         = "features.ctr_link_consistency",
           .voltype     = "features/changetimerecorder",
           .value       = "off",