1. MKDIR/RMDIR is recorded on all bricks. So if
   one brick succeeds creating it, other bricks
   should ignore it. But this was not happening.
   The fix rename of directories in hybrid crawl,
   was trying to rename the directory to itself
   and in the process crashing with ENOENT if the
   directory is removed.

2. If file is created, deleted and a directory is
   created with same name, it was failing to sync.
   Again the issue is around the fix for rename
   of directories in hybrid crawl. Fixed the same.

   If the same case was done with hardlink present
   for the file, it was failing. This patch fixes
   that too.

Backport of:
 > BUG: 1598884
 > Change-Id: I6f3bca44e194e415a3d4de3b9d03cc8976439284
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>

fixes: bz#1611114
Change-Id: I6f3bca44e194e415a3d4de3b9d03cc8976439284
Signed-off-by: Kotresh HR <khiremat@redhat.com>

Problem:
   Geo-rep sometimes fails to sync the rename of symlink
if the I/O is as follows

  1. touch file1
  2. ln -s "./file1" sym_400
  3. mv sym_400 renamed_sym_400
  4. mkdir sym_400

 The file 'renamed_sym_400' failed to sync to slave

Cause:
  Assume there are three distribute subvolume (brick1, brick2, brick3).
  The changelogs are recorded as follows for above I/O pattern.
  Note that the MKDIR is recorded on all bricks.

  1. brick1:
     -------

     CREATE file1
     SYMLINK sym_400
     RENAME sym_400 renamed_sym_400
     MKDIR sym_400

  2. brick2:
     -------

     MKDIR sym_400

  3. brick3:
     -------

     MKDIR sym_400

  The operations on 'brick1' should be processed sequentially. But
  since MKDIR is recorded on all the bricks, The brick 'brick2/brick3'
  processed MKDIR first before 'brick1' causing out of order syncing
  and created directory sym_400 first.

  Now 'brick1' processed it's changelog.

     CREATE file1 -> succeeds
     SYMLINK sym_400 -> No longer present in master. Ignored
     RENAME sym_400 renamed_sym_400
            While processing RENAME, if source('sym_400') doesn't
            present, destination('renamed_sym_400') is created. But
            geo-rep stats the name 'sym_400' to confirm source file's
            presence. In this race, since source name 'sym_400' is
            present as directory, it doesn't create destination.
            Hence RENAME is ignored.

Fix:
  The fix is not rely only on stat of source name during RENAME.
  It should stat the name and if the name is present, gfid should
  be same. Only then it can conclude the presence of source.

Backport of:
 > BUG: 1600405
 > Change-Id: I9fbec4f13ca6a182798a7f81b356fe2003aff969
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>

fixes: bz#1611113
Change-Id: I9fbec4f13ca6a182798a7f81b356fe2003aff969
Signed-off-by: Kotresh HR <khiremat@redhat.com>

Geo-rep mounts are private to worker. It uses
mount namespace using unshare command to achieve
the same. Well, the unshare command has to support
'--propagation' option. So geo-rep breaks on the
systems with older unshare version. The patch
makes it fall back to lazy umount behaviour if
the unshare does not support propagation option.

Backport of:
 > BUG: 1589782
 > Change-Id: Ia614f068aede288d63ac62fea4461b1865066054
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>

fixes: bz#1611111
Change-Id: Ia614f068aede288d63ac62fea4461b1865066054
Signed-off-by: Kotresh HR <khiremat@redhat.com>

Cause and Analysis:
The last synced changelog for entry operations is
marked in current version to avoid re-processing
of already processed entry operations in a batch
during crash/restart of geo-rep. This was not
present in previous versoins.

The marker is maintained in the dictionary with the
key 'last_synced_entry' and dictionary is persisted
into status file. So upgrading to current version in
which the marker is present was failing with KeyError.

Solution:
Load the dictionary with default keys first which
contains all the keys including latest ones and then
load the values from status file instead of doing
otherwise.

Backport of:
 > BUG: 1575490
 > Change-Id: Ic654e6f9a3c97f616761f1362f890352a2186fb4
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>
 (cherry picked from commit 23c1385b5f6f6103e820d15ecfe1df31940fdb45)

fixes: bz#1611104
Change-Id: Ic654e6f9a3c97f616761f1362f890352a2186fb4
Signed-off-by: Kotresh HR <khiremat@redhat.com>
(cherry picked from commit 23c1385b5f6f6103e820d15ecfe1df31940fdb45)

see https://review.gluster.org/#/c/19788/

use print fn from __future__

Change-Id: If5075d8d9ca9641058fbc71df8a52aa35804cda4
updates: #411
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>

Problem:
If symlink is created on master pointing
to current directory (e.g symlink -> ".") with
non root uid or gid, geo-rep worker crashes
with ENOTSUP.

Cause:
Geo-rep creates the symlink on slave and
fixes the uid and gid using chown cmd.
os.chown dereferences the symlink which is
pointing to ".gfid" which is not supported.
Note that geo-rep operates on aux-gfid-mount
(e.g. "/mnt/.gfid/<gfid-of-symlink-file>").

Solution:
The uid or gid change is acutally on symlink
file. So use os.lchown, i.e, don't deference.

BUG: 1567209
Change-Id: I63575fc589d71f987bef1d350c030987738c78ad
updates: bz#1567209
Signed-off-by: Kotresh HR <khiremat@redhat.com>

Note 1) we're not supposed to be using #!/usr/bin/env python, see
https://fedoraproject.org/wiki/Packaging:Guidelines?rd=Packaging/Guidelines#Shebang_lines

Note 2) we're also not supposed to be using "!/usr/bin/python,
see https://fedoraproject.org/wiki/Changes/Avoid_usr_bin_python_in_RPM_Build#Quick_Opt-Out

The previous patch (https://review.gluster.org/19767) tried to do too
much in one patch, so it was abandoned.

This patch does two things:
1) minor cleanup of configure(.ac) to explicitly use python2
2) change all the shebang lines to #!/usr/bin/python2 and add them
where they were missing based on warnings emitted during rpmbuild.

In a follow-up patch python2 will eventually be changed to python3.

Before that python2-isms (e.g. print, string.join(), etc.) need to be
converted to python3. Some of those can be rewritten in version agnostic
python. E.g. print statements become print() with "from __future_ import
print_function". The python 2to3 utility will be used for some of those.
Also Aravinda has given guidance in the comments to the first patch for
changes.

updates: #411
Change-Id: I471730962b2526022115a1fc33629fb078b74338
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>

`find_library()` doesn't consider LD_LIBRARY_PATH on Python < 3.6.

Change-Id: Iee26085cb5d14061001f19f032c2664d69a378a8
BUG: 1450593
Signed-off-by: Niklas Hambüchen <mail@nh2.me>

Lazy umounting the master volume by worker causes
issues with rsync's usage of getcwd. Henc removing
the lazy umount and using private mount namespace
for the same. On the slave, the lazy umount is
retained as we can't use private namespace in non
root geo-rep setup.

Change-Id: I403375c02cb3cc7d257a5f72bbdb5118b4c8779a
BUG: 1546129
Signed-off-by: Kotresh HR <khiremat@redhat.com>

JSON output of `config-get` command now returns in the following
format

    {
        "name": CONFIG_NAME,
        "value": CONFIG_VALUE,
        "default_value": DEFAULT_VALUE,  # Only if modified == true
        "configurable": true|false,
        "modified": true|false
    }

Change-Id: I6193de48cd33655df7ecef5a0d83d7cb147089cf
Fixes: #361
Signed-off-by: Aravinda VK <avishwan@redhat.com>