[bitbake-devel] [PATCH] bitbake: fetch2/svn: Fix SVN repository concurrent update race

[Ulf.Magnusson at bmw.de]

> > The ${DL_DIR}/svn directory is used by BitBake to keep checked-out SVN
> > repositories from which tarballs are generated. These repositories were
> > protected from concurrent update with a lock on the tarballs. However,
> > the tarballs are specific to the SRCREV and module checked out (many
> > tarballs can come from the same repository), meaning a repository could
> > be modified concurrently if two recipes checked out two different
> > SRCREVs or modules from it in parallel.
> > 
> > This caused errors like the following:
> > 
> > ERROR: Fetcher failure: Fetch command failed with exit code 1, output:
> > svn: E155004: Run 'svn cleanup' to remove locks (type 'svn help cleanup' for details)
> > svn: E155004: Working copy '/home/foo/downloads/svn/repo/trunk' locked.
> > svn: E155004: '/home/foo/downloads/svn/repo/trunk' is already locked.
> > 
> > Fix it by adding a per-repository lock that's independent of the module
> > and SRCREV.
> > ---
> >  bitbake/lib/bb/fetch2/svn.py | 69 +++++++++++++++++++++++++-------------------
> >  1 file changed, 39 insertions(+), 30 deletions(-)
> > 
> > diff --git a/bitbake/lib/bb/fetch2/svn.py b/bitbake/lib/bb/fetch2/svn.py
> > index 8a29193..f83b740 100644
> > --- a/bitbake/lib/bb/fetch2/svn.py
> > +++ b/bitbake/lib/bb/fetch2/svn.py
> > @@ -63,6 +63,9 @@ class Svn(FetchMethod):
> >          relpath = self._strip_leading_slashes(ud.path)
> >          ud.pkgdir = os.path.join(data.expand('${SVNDIR}', d), ud.host, relpath)
> >          ud.moddir = os.path.join(ud.pkgdir, ud.module)
> > +        # Protects the repository from concurrent updates, e.g. from two
> > +        # recipes fetching different revisions at the same time
> > +        ud.svnlock = os.path.join(ud.pkgdir, "svn.lock")
> >  
> >          ud.setup_revisons(d)
> >  
> > @@ -123,38 +126,44 @@ class Svn(FetchMethod):
> >  
> >          logger.debug(2, "Fetch: checking for module directory '" + ud.moddir + "'")
> >  
> > -        if os.access(os.path.join(ud.moddir, '.svn'), os.R_OK):
> > -            svnupdatecmd = self._buildsvncommand(ud, d, "update")
> > -            logger.info("Update " + ud.url)
> > -            # update sources there
> > -            os.chdir(ud.moddir)
> > -            # We need to attempt to run svn upgrade first in case its an older working format
> > -            try:
> > -                runfetchcmd(ud.basecmd + " upgrade", d)
> > -            except FetchError:
> > -                pass
> > -            logger.debug(1, "Running %s", svnupdatecmd)
> > -            bb.fetch2.check_network_access(d, svnupdatecmd, ud.url)
> > -            runfetchcmd(svnupdatecmd, d)
> > -        else:
> > -            svnfetchcmd = self._buildsvncommand(ud, d, "fetch")
> > -            logger.info("Fetch " + ud.url)
> > -            # check out sources there
> > -            bb.utils.mkdirhier(ud.pkgdir)
> > -            os.chdir(ud.pkgdir)
> > -            logger.debug(1, "Running %s", svnfetchcmd)
> > -            bb.fetch2.check_network_access(d, svnfetchcmd, ud.url)
> > -            runfetchcmd(svnfetchcmd, d)
> > +        lf = bb.utils.lockfile(ud.svnlock)
> > +
> > +        try:
> > +            if os.access(os.path.join(ud.moddir, '.svn'), os.R_OK):
> > +                svnupdatecmd = self._buildsvncommand(ud, d, "update")
> > +                logger.info("Update " + ud.url)
> > +                # update sources there
> > +                os.chdir(ud.moddir)
> > +                # We need to attempt to run svn upgrade first in case its an older working format
> > +                try:
> > +                    runfetchcmd(ud.basecmd + " upgrade", d)
> > +                except FetchError:
> > +                    pass
> > +                logger.debug(1, "Running %s", svnupdatecmd)
> > +                bb.fetch2.check_network_access(d, svnupdatecmd, ud.url)
> > +                runfetchcmd(svnupdatecmd, d)
> > +            else:
> > +                svnfetchcmd = self._buildsvncommand(ud, d, "fetch")
> > +                logger.info("Fetch " + ud.url)
> > +                # check out sources there
> > +                bb.utils.mkdirhier(ud.pkgdir)
> > +                os.chdir(ud.pkgdir)
> > +                logger.debug(1, "Running %s", svnfetchcmd)
> > +                bb.fetch2.check_network_access(d, svnfetchcmd, ud.url)
> > +                runfetchcmd(svnfetchcmd, d)
> > +
> > +            scmdata = ud.parm.get("scmdata", "")
> > +            if scmdata == "keep":
> > +                tar_flags = ""
> > +            else:
> > +                tar_flags = "--exclude '.svn'"
> >  
> > -        scmdata = ud.parm.get("scmdata", "")
> > -        if scmdata == "keep":
> > -            tar_flags = ""
> > -        else:
> > -            tar_flags = "--exclude '.svn'"
> > +            os.chdir(ud.pkgdir)
> > +            # tar them up to a defined filename
> > +            runfetchcmd("tar %s -czf %s %s" % (tar_flags, ud.localpath, ud.path_spec), d, cleanup = [ud.localpath])
> >  
> > -        os.chdir(ud.pkgdir)
> > -        # tar them up to a defined filename
> > -        runfetchcmd("tar %s -czf %s %s" % (tar_flags, ud.localpath, ud.path_spec), d, cleanup = [ud.localpath])
> > +        finally:
> > +            bb.utils.unlockfile(lf)
> >  
> >      def clean(self, ud, d):
> >          """ Clean SVN specific files and dirs """
> > -- 
> > 2.7.4
> 
> An easy way to reproduce the problem is with two recipes like the following:
> 
> first.bb:
> 
> SRC_URI = "svn://moderately.big.repo.com;module=trunk;protocol=https"
> SRCREV = "1"
> 
> 
> second.bb:
> 
> SRC_URI = "svn://moderately.big.repo.com;module=trunk;protocol=https"
> SRCREV = "2"
> 
> 
> Running 'bitbake first second' with empty download/sstate caches is then very
> likely to trigger the issue.
> 
> Here's another guy that I think was having the same problem:
> https://lists.yoctoproject.org/pipermail/yocto/2014-August/021383.html
> 
> Cheers,
> Ulf

Ping!

Cheers,
Ulf