Use versioned symbols to keep libgfapi at libgfapi.so.0.0.0

Revisited to address broken build on Mac OS X

See http://review.gluster.org/9036

Rebased to include http://review.gluster.org/#/c/9376/ (glfs_resolve())
but note that gerrit's "Rebase Change" couldn't do it.

N.B. noticed that glfs_get_volumeid() decl in glfs.h was missing
the __THROW, added it.

On systems using ELF and the GNU toolchain, symbol versions are created
with a .symver asm operand in the .c source file. Clang is claimed to
be compatible with gcc, so we'll pretend for now that this also works
with clang.

On Mac OS X, aliases are created with __asm "magic" in the .h header
file. In the normal case, when both the decl and defn match, that's
all that's needed. In our case though the decl and defn don't match ---
we have, e.g. a defn such as 'int glfs_foo(...)' and the corresponding
decl is 'int pub_glfs_foo(...)'. To make this work we create the necessary
aliases in the library at link time with the -alias_list link option.

Note that this results in there being pairs of symbols in the .dylib,
e.g. _pub_glfs_foo and _glfs_foo$GFAPI_3.4.0. We could use another
link option, -unexported_symbols_list to elide the _pub_glfs_* symbols.
(And we probably should.)

Linux symbol versioning was essentially copied from Solaris; in general
I would expect this to "just work" on Solaris, but until someone tries
we don't really know.

Change-Id: Icb96a3c2d80be7b6d7a6849bb9168f03a947f47c
BUG: 1160709
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>

This is an improvement over the patch 'http://review.gluster.org/9337'
to trigger explicit geo-rep sync on regular files even if entry is not
present on the slave. An attempt is made to find the pargfid and
if available captures CREATE along with DATA in changelog.
CREATE is captured with default file permissions. Setting this virtual
setxattr on directories captures MKDIR in changelog. The value of
setxattr can be as follows.

If value = "1"       : Both CREATE and DATA is captured in changelog if
                       pargfid is available, else on DATA is captured.
   value = "any other: ENOTSUP is returned.

Usage:
  setfattr -n glusterfs.geo-rep.trigger-sync -v "1" <file-path>

NOTE: This patch supports explicit record of entries only for
      directories and regular files.

Change-Id: Iedde8b2c8bc3b78db524050d8c866ff664811d01
BUG: 1176934
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/9370
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Tested-by: Venky Shankar <vshankar@redhat.com>

Problem:
Internal xattrs of EC like trusted.ec.size/config/version
can be modified by users and that can lead to misbehavior
in EC.

Fix:
Don't let the user modify the xattrs. Hide these xattrs
in getfattr outputs.

Change-Id: I39cec96ae12826b506b496fda7da74201015fd75
BUG: 1178688
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/9385
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Emmanuel Dreyfus <manu@netbsd.org>
Tested-by: Emmanuel Dreyfus <manu@netbsd.org>
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>

Problem:
EC heal tries to heal quota-size, selinux xattrs as well.  quota-size is
private to the brick but since quotad accesses them using the standard
interface as well, they can not be filtered in the fops.

Fix:
Ignore QUOTA_SIZE_KEY and SELINUX xattrs during heal.

Change-Id: I1572f9e2fcba7f120b4265e034953a15ff297f04
BUG: 1179640
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/9401
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>
Tested-by: Gluster Build System <jenkins@build.gluster.com>