s3: Avoid oplock break by storing timestamps with gpfs_set_times

s3: Avoid oplock break by storing timestamps with gpfs_set_times

The gpfs_set_times API call allows setting timestamps directly in GPFS
without going through the utime() call. Using this API call fixes an
unecessary oplock break when a client sends a SET_FILE_ALLOCATION_INFO
request and no other client has opened the file. The call to utime()
triggers the oplock break through the Linux kernel. Using the
gpfs_set_times call for updating the timestamp avoids the call to
utime() and the oplock break.

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Christof Schmitt <cs@samba.org>
Autobuild-Date(master): Thu Jan  9 00:04:48 CET 2014 on sn-devel-104