When a translator stops, memory accounting for that translator is not
destroyed (because there could remain memory allocated that references
it), but mutexes that coordinate updates of memory accounting were
destroyed. This caused incorrect memory accounting and even crashes in
debug mode.

This patch also fixes some other things:

* Reduce the number of atomic operations needed to manage memory
  accounting.
* Correctly account memory when realloc() is used.
* Merge two critical sections into one.
* Cleaned the code a bit.

Backport of:
> Change-Id: Id5eaee7338729b9bc52c931815ca3ff1e5a7dcc8
> BUG: bz#1659334
> Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

Change-Id: Id5eaee7338729b9bc52c931815ca3ff1e5a7dcc8
Fixes: bz#1702271
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

Problem: When rpc-transport-disconnect happens, server_connection_cleanup_flush_cbk() 
         is supposed to call rpc_transport_unref() after open-files on 
         that transport are flushed per transport.But open-fd-count is 
         maintained in bound_xl->fd_count, which can be incremented/decremented 
         cumulatively in server_connection_cleanup() by all transport 
         disconnect paths. So instead of rpc_transport_unref() happening 
         per transport, it ends up doing it only once after all the files 
         on all the transports for the brick are flushed leading to 
         rpc-leaks.

Solution: To avoid races maintain fd_cnt at client instead of maintaining
          on brick

Credits: Pranith Kumar Karampuri
Change-Id: I6e8ea37a61f82d9aefb227c5b3ab57a7a36850e6
fixes: bz#1668190
Signed-off-by: Mohit Agrawal <moagrawal@redhat.com>

* Remove the options to load old symbol.
* keep only 'xlator_api' symbol from being exported using xlator.sym
* add xlator_api to all the xlators where its missing

NOTE: This covers all the xlators which has at least a test case
to validate its loading. If there is a translator, which doesn't
have any test, then we should probably remove that from codebase.

fixes: #164
Change-Id: Ibcdc8c9844cda6b4463d907a15813745d14c1ebb
Signed-off-by: Amar Tumballi <amarts@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>

libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation <> in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR <srangana@redhat.com>