Problem:
The files which were created before ctime enabled would not
have "trusted.glusterfs.mdata"(stores time attributes) xattr.
Upon fops which modifies either ctime or mtime, the xattr
gets created with latest ctime, mtime and atime, which is
incorrect. It should update only the corresponding time
attribute and rest from backend

Solution:
Creating xattr with values from brick is not possible as
each brick of replica set would have different times.
So create the xattr upon successful lookup if the xattr
is not created

Note To Reviewers:
The time attributes used to set xattr is got from successful
lookup. Instead of sending the whole iatt over the wire via
setxattr, a structure called mdata_iatt is sent. The mdata_iatt
contains only time attributes.

Backport of:
 > Patch:  https://review.gluster.org/22936
 > Change-Id: I5e535631ddef04195361ae0364336410a2895dd4
 > BUG: 1593542
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>

Change-Id: I5e535631ddef04195361ae0364336410a2895dd4
updates: bz#1733885
Signed-off-by: Kotresh HR <khiremat@redhat.com>

    * libglusterfs changes to add new fop

    * Fuse changes:
      - Changes in fuse bridge xlator to receive and send responses

    * posix changes to perform the op on the backend filesystem

    * protocol and rpc changes for sending and receiving the fop

    * gfapi changes for performing the fop

    * tools: glfs-copy-file-range tool for testing copy_file_range fop

      - Although, copy_file_range support has been added to the upstream
	    fuse kernel module, no release has been made yet of a kernel
        which contains the support. It is expected to come in the
        upcoming release of linux-4.20

        So, as of now, executing copy_file_range fop on a fused based
        filesystem results in fuse kernel module sending read on the
	    source fd and write on the destination fd.

	    Therefore a small gfapi based tool has been written to be able
        test the copy_file_range fop. This tool is similar (in functionality)
	    to the example program given in copy_file_range man page.

	    So, running regular copy_file_range on a fuse mount point and
	    running gfapi based glfs-copy-file-range tool gives some idea about
	    how fast, the copy_file_range (or reflink) can be.

	    On the local machine this was the result obtained.

	    mount -t glusterfs workstation:new /mnt/glusterfs
	    [root@workstation ~]# cd /mnt/glusterfs/
	    [root@workstation glusterfs]# ls
	    file
	    [root@workstation glusterfs]# cd
	    [root@workstation ~]# time /tmp/a.out /mnt/glusterfs/file /mnt/glusterfs/new
	    real  0m6.495s
	    user  0m0.000s
	    sys   0m1.439s
	    [root@workstation ~]# time glfs-copy-file-range $(hostname) new /tmp/glfs.log /file /rrr
	    OPEN_SRC: opening /file is success
	    OPEN_DST: opening /rrr is success
	    FSTAT_SRC: fstat on /rrr is success
	    copy_file_range successful

        real  0m0.309s
        user  0m0.039s
        sys   0m0.017s

        This tool needs following arguments
         1) hostname
         2) volume name
         3) log file path
         4) source file path (relative to the gluster volume root)
         5) destination file path (relative to the gluster volume root)

        "glfs-copy-file-range <hostname> <volume> <log file path> <source> <destination>"

      - Added a testcase as well to run glfs-copy-file-range tool

    * io-stats changes to capture the fop for profiling

    * NOTE:

      - Added conditional check to see whether the copy_file_range syscall
        is available or not. If not, then return ENOSYS.

      - Added conditional check for kernel minor version in fuse_kernel.h
        and fuse-bridge while referring to copy_file_range. And the kernel
        minor version is kept as it is. i.e. 24. Increment it in future
        when there is a kernel release which contains the support for
        copy_file_range fop in fuse kernel module.

    * The document which contains a writeup on this enhancement can be found at
      https://docs.google.com/document/d/1BSILbXr_knynNwxSyyu503JoTz5QFM_4suNIh2WwrSc/edit

Change-Id: I280069c814dd21ce6ec3be00a884fc24ab692367
updates: #536
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>

Updates #353
Change-Id: I755b9208690be76935d763688fa414521eba3a40
Signed-off-by: Poornima G <pgurusid@redhat.com>

With this patchset, some major things are changed in XDR, mainly:

* Naming: Instead of gfs3/gfs4 settle for gfx_ for xdr structures
* add iattx as a separate structure, and add conversion methods
* the *_rsp structure is now changed, and is also reduced in number
  (ie, no need for different strucutes if it is similar to other response).
* use proper XDR methods for sending dict on wire.

Also, with the change of xdr structure, there are changes needed
outside of xlator protocol layer to handle these properly. Mainly
because the abstraction was broken to support 0-copy RDMA with payload
for write and read FOP. This made transport layer know about the xdr
payload, hence with the change of xdr payload structure, transport layer
needed to know about the change.

Updates #384

Change-Id: I1448fbe9deab0a1b06cb8351f2f37488cefe461f
Signed-off-by: Amar Tumballi <amarts@redhat.com>

Introduce another authentication header which can now send more data.
This is useful because this data can be common for all the fops, and
we don't need to change all the signatures.

As part of this, made rpc-clnt.c little more modular to support multiple
authentication structures.

stack.h changes are placeholder for the ctime etc, can be moved later
based on need.

updates #384

Change-Id: I6111c13cfd2ec92e2b4e9295896bf62a8a33b2c7
Signed-off-by: Amar Tumballi <amarts@redhat.com>

The locks xlator now is able to send a contention notification to
the current owner of the lock.

This is only a notification that can be used to improve performance
of some client side operations that might benefit from extended
duration of lock ownership. Nothing is done if the lock owner decides
to ignore the message and to not release the lock. For forced
release of acquired resources, leases must be used.

Change-Id: I7f1ad32a0b4b445505b09908a050080ad848f8e0
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>

Without an export map (at link time) libgrpc and libgfxdr export over
150 and 450 symbols each, respectively. Many are not used by anything
else. (Unclear what the unused symbols are, some may be simple
sloppiness, e.g. not declaring functions static that should be. Others
may be intra-library calls that can't be static but aren't part of the
API, per se.)

By linking with an export map the number of exported symbols is
reduced to ~60 and ~250 respectively.

This parallels the similar change made to libglusterfs recently
and the older changes to the xlators to minimize the symbols that
are visible (exported) from the .so.

And I don't know, do we want to go all the way to symbol versions?
For these libs? And for libglusterfs?

fixes gluster/glusterfs#392

Change-Id: I9cdc3eee10e5f1408d7e7f2f29fad597c97e4003
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>