[Gluster-devel] [PATCH v7] vfs_glusterfs: Samba VFS module for glusterfs

[Anand Avati]

On 05/28/2013 03:42 PM, Anand Avati wrote:
>
>
>
> On Tue, May 28, 2013 at 2:46 PM, Andrew Bartlett <abartlet at samba.org
> <mailto:abartlet at samba.org>> wrote:
>
>     On Tue, 2013-05-28 at 17:36 -0400, Anand Avati wrote:
>      > Implement a Samba VFS plugin for glusterfs based on gluster's gfapi.
>      > This is a "bottom" vfs plugin (not something to be stacked on top of
>      > another module), and translates (most) calls into closest actions
>      > on gfapi.
>
>     Thank you for your patience here.
>
>      > Signed-off-by: Anand Avati <avati at redhat.com
>     <mailto:avati at redhat.com>>
>      > ---
>      >
>      > Hi,
>      >
>      > I hope the waf changes are fine. I could not test them because
>     builds were failing generally on samba.git master HEAD.
>
>     You need to resolve whatever is causing your problems here, as it is not
>     a general issue. Our autobuild system ensures that git master and
>     v4-0-test always compile and test in at least Ubuntu 10.04, and it is
>     incredibly rare that it not work on at least Linux without it being a
>     specifically local issue.
>
>     +
>     +bld.SAMBA3_MODULE('vfs_glusterfs',
>     +                  subsystem='vfs',
>     +                  source=VFS_GLUSTERFS_SRC,
>     +                  deps='samba-util',
>     +                  init_function='',
>     +
>       internal_module=bld.SAMBA3_IS_STATIC_MODULE('vfs_glusterfs'),
>     +
>       enabled=bld.SAMBA3_IS_ENABLED_MODULE('vfs_glusterfs'))
>
>     You should ensure your module depends on glusterfs, by changing that to
>     adding deps='glusterfs samba-util' (and making that match what the
>     conf.check_cfg finds and stores).
>
>
> I tried that. I added uselib_store='glusterfs' and included 'glusterfs'
> in deps= line. However while building I get this error:
>
> [avati at blackbox samba]$ make
> WAF_MAKE=1 python ./buildtools/bin/waf build
> ./buildtools/wafsamba/samba_utils.py:397: DeprecationWarning: the md5
> module is deprecated; use hashlib instead
>    import md5
> Waf: Entering directory `/home/avati/work/samba/bin'
> Selected embedded Heimdal build
> Checking project rules ...
> Unknown dependency 'glusterfs' in 'vfs_glusterfs'
> make: *** [all] Error 1
>
>
> I am not familiar with waf, and trying to figure out how it works. I
> don't understand how the check_cfg() in wscript and
> source3/wscript_build's bld.SAMBA3_MODULE() actually integrate internally.
>
>      > diff --git a/source3/wscript b/source3/wscript
>      > index dba6cdc..0d07692 100644
>      > --- a/source3/wscript
>      > +++ b/source3/wscript
>      > @@ -59,6 +59,11 @@ def set_options(opt):
>      >                     help=("Directory under which libcephfs is
>     installed"),
>      >                     action="store", dest='libcephfs_dir',
>     default=None)
>      >
>      > +    opt.add_option('--enable-glusterfs',
>      > +                   help=("Enable building vfs_glusterfs module"),
>      > +                   action="store_true", dest='enable_glusterfs',
>     default=True)
>      > +    opt.add_option('--disable-glusterfs', help=SUPPRESS_HELP,
>      > +                   action="store_false", dest='enable_glusterfs')
>
>     In general we would prefer not to have options for every possible
>     module.  Instead, please just make it automatic based on finding
>     glusterfs.
>
>
> OK, I will just leave things to check_cfg() detection then?
>
>      >  def configure(conf):
>      > @@ -1709,6 +1714,13 @@ main() {
>      >      if conf.CHECK_HEADERS('cephfs/libcephfs.h', False, False,
>     'cephfs') and conf.CHECK_LIB('cephfs'):
>      >          conf.DEFINE('HAVE_CEPH', '1')
>      >
>      > +    conf.env.enable_glusterfs = Options.options.enable_glusterfs
>      > +
>      > +    if Options.options.enable_glusterfs:
>      > +        conf.check_cfg(package='glusterfs-api',
>     args='"glusterfs-api >= 4" --cflags --libs',
>      > +                       uselib_store='GLUSTERFS', msg='Checking
>     for glusterfs-api >= 4',
>      > +                       mandatory=False)
>      > +
>      >      conf.env.build_regedit = False
>      >      if not Options.options.with_regedit == False:
>      >          conf.PROCESS_SEPARATE_RULE('system_ncurses')
>      > @@ -1797,6 +1809,9 @@ main() {
>      >      if conf.CONFIG_SET("HAVE_CEPH"):
>      >          default_shared_modules.extend(TO_LIST('vfs_ceph'))
>      >
>      > +    if conf.CONFIG_SET('HAVE_GLUSTERFS'):
>      > +        default_shared_modules.extend(TO_LIST('vfs_glusterfs'))
>      > +
>      >      explicit_shared_modules =
>     TO_LIST(Options.options.shared_modules, delimiter=',')
>      >      explicit_static_modules =
>     TO_LIST(Options.options.static_modules, delimiter=',')
>
>     This much looks good, assuming it is tested and works.   You might need
>     to make uselib_store='glusterfs' (not sure).
>
>
> As mentioned above, I tried this but still get the dependency error. Not
> sure what I am missing..
>

I tried to look up documentation on the web, but I couldn't find 
anything specific. My understanding so far is:

conf.check_cfg(...) does the 'detection' and stores the result in 
variables. You can specify a variable name prefix with uselib_store=NAME 
parameter.

You can then use the test results while building, with a construct like:

bld.new_task_gen(..., uselib=NAME, ...)

However, samba is using bld.SAMBA3_MODULE(...) for building, and that 
does not seem to be accepting uselib= parameter.

What I am trying to achieve is:

- detect for presence of glusterfs headers/libs in the buildsystem. This 
is detected with the presence of glusterfs-api.pc

- use the --libs and --cflags from pkg-config on glusterfs-api.pc to 
build vfs_glusterfs.c

I know how to do this in autotools. I am not familiar with waf, and it 
doesn't seem to be intuitive enough to be self understood. There seems 
to be quite a lot of macro hackery around it which makes the techniques 
you get from a google search "not applicable".

Any help from the waf experts will be most appreciated!

Avati