mgmt/gluster: Use fsync instead of O_SYNC

Glusterd uses O_SYNC to write to temp file then performs renames
to the actual file and performs fsync on parent directory. Until
this rename happens syncing writes to the file can be deferred.
In this patch O_SYNC open of temp file is removed and fsync of the
fd before rename is done.

Change-Id: Ie7da161b0daec845c7dcfab4154cc45c2f49d825
BUG: 908277
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/7370
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>
statedump: strfd based APIs

Expose strfd based APIs for extracing various types of xlator
state information.

Change-Id: Ibbb6594b6fb31206bc6a1b1ea6514ed41889583b
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7540
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
mem-accounting: store type string and print in meta

Change-Id: Ied1de473c72967110b54f033768f7ac60bf66edc
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7541
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
mem-accounting: enable memory accounting by default

memory accounting are constant time operations which
involve a few pointer dereferences and integer increments
(no loops or searches etc.)

benefits of having memory usage info outweigh the minor
accounting overheads

Change-Id: If9bc6db5ffd0e00f0fd64b2f6eed094bf3543996
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7543
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
meta: (re-)Implement Meta translator

The meta translator exposes details about glusterfs itself
in the form of a virtual namespace.

Loading the translator on the client side creates the
meta virtual view under $mntpoint/.meta by default. The
directory is not listed (even with ls -a) and can be
accessed by doing a "cd /mnt/.meta"

Change-Id: I5ffdf39203841a9562a8280a1f79dc76d4dded5d
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7509
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
meta: export process state dump

Various parts of process state dump are exposed
through most appropriate virual files/dirs

Change-Id: Iff30f8ea76552f2f6d9c98def688c5ec4bc6f2af
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7542
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
meta: print in json for stack/frames, cmdline and version

- Follow formatting rules based on RFC4627 -
  http://www.ietf.org/rfc/rfc4627.txt
- Add checks for json in regression test meta.t

Change-Id: I480d32ce042b202d3ed8939623c629a03b458551
BUG: 1089216
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/7653
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>