storage/posix: Fix race in posix_pstat

Problem:
When one thread is in the process of creating a file/directory
and the other thread is doing readdirp, there is a chance that
posix_pstat, creation fops race in the following manner which
will lead to wrong stat values to be read by parent xlators
like posix-acl.

Creation fops                           posix_pstat() as part of readdirp
1) file is created with uid/gid 0/0     1) does stat of the path that
                                           is created just now.
2) Does chown to set the correct
   uid/gid
3) Sets the acl/user/internal xattrs
4) Sets the gfid on the entry and
   completes the creation of the file/dir
                                        2) fills the gfid in the iatt

If unwind of readdirp hits server xlator before creation fop, then
posix-acl remembers uid/gid of the file to be root/root and fails
fops like open etc on it.

Fix:
Reverse the order of filling gfid and filling lstat() values in
posix_pstat() so that if there is gfid in iatt buffer uid/gid
are valid.

 >Change-Id: I46caa7f6da7abfa40a0b1d70e35b88de9c64959c
 >Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
 >Reviewed-on: http://review.gluster.org/15564
 >NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
 >CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
 >Smoke: Gluster Build System <jenkins@build.gluster.org>
 >Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

BUG: 1386071
Change-Id: I81c4c6e6b8d4037cee9b23da262b254c126c0a19
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/15665
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>

0 files changed, 0 insertions, 0 deletions