[OE-core] [oe-core][dizzy][PATCH] base-files: Check for /run and /var/lock softlinks on upgrade

Tue Apr 14 20:41:54 UTC 2015

All,

> -----Original Message-----
> From: Bryan Evenson
> Sent: Tuesday, April 14, 2015 11:47 AM
> To: Bryan Evenson; openembedded-core at lists.openembedded.org
> Subject: RE: [oe-core][dizzy][PATCH] base-files: Check for /run and /var/lock
> softlinks on upgrade
> 
> All,
> 
> > -----Original Message-----
> > From: Bryan Evenson [mailto:bevenson at melinkcorp.com]
> > Sent: Friday, April 10, 2015 12:44 PM
> > To: openembedded-core at lists.openembedded.org
> > Cc: Bryan Evenson
> > Subject: [oe-core][dizzy][PATCH] base-files: Check for /run and
> > /var/lock softlinks on upgrade
> >
> > Commit ea647cd9eebdc3e3121b84074519c4bb305adac9 moved the
> locations of
> > /run and /var/lock to match the FHS 3 draft specifications.
> > However, the install doesn't remove the existing directories.
> > As a result, upgrading a system may result in /run as a softlink to
> > /var/run and /var/run as a softlink to /run, creating a circular link.
> >
> > During pre and post-install, check for the existence of the old
> > softlinks, move the old file contents to a temporary location, remove
> > the softlinks, and restore the directory contents after installation.
> >
> 
> I went about this wrong, as I forgot that items may be mounted under /run.
> I'm working on a different solution in which the preinst step removes the
> /run and /var/lock softlinks if they exist.  However, I still have odd issues.
> The first reboot works fine, but then on the next reboot there is a link inside
> /run for "run -> /var/run" and inside /var there is a link for "run ->
> /var/volatile/run".  This doesn't match up with the files listed in the base-files
> recipe.  I can't figure out where these links are coming from.  Has anyone else
> had issues upgrading base-files?

The root cause seems to be the initscripts package.  The script /etc/volatile.cache is generated by /etc/init.d/populate-volatile.sh.  On upgrade, this file is not removed and may not necessarily be regenerated.  As a result, on the next boot the script /etc/volatile.cache repopulates directories as it remembers them which may not be accurate.  In my case, after the reboot, the /etc/volatile.cache script deleted everything from a USB flash drive attached to my system when it attempted to remove /run.

So to get this portion of the upgrade to work, I had to:
1. Remove the softlinks for /run and /var/lock through a preinst script in the base-files recipe
2. Remove /etc/volatile.cache as a postint script in the initscripts recipe

Would someone like for me to submit a patch?

Thanks,
Bryan

> 
> Thanks,
> Bryan
> 
> > Signed-off-by: Bryan Evenson <bevenson at melinkcorp.com>
> > ---
> >  meta/recipes-core/base-files/base-files_3.0.14.bb | 55
> > +++++++++++++++++++++++
> >  1 file changed, 55 insertions(+)
> >
> > diff --git a/meta/recipes-core/base-files/base-files_3.0.14.bb
> > b/meta/recipes-core/base-files/base-files_3.0.14.bb
> > index 07f5c54..71cea08 100644
> > --- a/meta/recipes-core/base-files/base-files_3.0.14.bb
> > +++ b/meta/recipes-core/base-files/base-files_3.0.14.bb
> > @@ -66,6 +66,41 @@ hostname = "openembedded"
> >
> >  BASEFILESISSUEINSTALL ?= "do_install_basefilesissue"
> >
> > +# In previous versions of base-files, /run was a softlink to /var/run
> > +and the # directory was located in /var/volatlie/run.  Also,
> > +/var/lock was a softlink # to /var/volatile/lock which is where the
> > +real directory was located.  Now, # /run and /run/lock are the real
> > +directories.  If we are upgrading, we may # need to remove the symbolic
> links first before we create the directories.
> > +# Otherwise the directory creation will fail and we will have
> > +circular symbolic # links.
> > +#
> > +# If we do need to remove the symbolic links first, we also need to
> > +preserve # all the contents of the directory so running programs can
> > +find the files that # are in use in these directories.  Move the
> > +contents to a temporary
> > directory
> > +# during pre-install to protect the contents pkg_preinst_${PN} () {
> > +    #!/bin/sh -e
> > +    if [ x"$D" = "x" ]; then
> > +        if [ -e "/var/volatile/lock" ]; then
> > +            # Move the contents of /var/volatile/lock to a temporary directory
> > +            mkdir -p /run_lock_tmp
> > +            mv /var/volatile/lock/* /run_lock_tmp/
> > +
> > +            # Remove the current directory
> > +            rm -rf /var/volatile/lock
> > +        fi
> > +
> > +        if [ -h "/run" ]; then
> > +            # Move the contents of /run to a temporary directory
> > +            mkdir -p /run_tmp
> > +            mv /run/* /run_tmp/
> > +
> > +            # Remove the current directory
> > +            rm -rf /run
> > +        fi
> > +    fi
> > +}
> > +
> >  do_install () {
> >  	for d in ${dirs755}; do
> >  		install -m 0755 -d ${D}$d
> > @@ -79,6 +114,7 @@ do_install () {
> >  	for d in ${volatiles}; do
> >  		ln -sf volatile/$d ${D}${localstatedir}/$d
> >  	done
> > +
> >  	ln -snf ../run ${D}${localstatedir}/run
> >  	ln -snf ../run/lock ${D}${localstatedir}/lock
> >
> > @@ -144,6 +180,25 @@ do_install_append_linuxstdbase() {
> >          done
> >  }
> >
> > +# If we are on the actual hardware, check if we had to move /run and
> > /run/lock.
> > +# If so, copy the temporary directory contents to their new locations.
> > +pkg_postinst_${PN} () {
> > +    #!/bin/sh -e
> > +    if [ x"$D" = "x" ]; then
> > +        if [ -e "/run_tmp" ]; then
> > +            mv /run_tmp/* /run/
> > +            rmdir /run_tmp
> > +        fi
> > +
> > +        if [ -e "/run_lock_tmp/" ]; then
> > +            mv /run_lock_tmp/* /run/lock
> > +            rmdir /run_lock_tmp
> > +        fi
> > +    else
> > +        exit 1
> > +    fi
> > +}
> > +
> >  PACKAGES = "${PN}-doc ${PN} ${PN}-dev ${PN}-dbg"
> >  FILES_${PN} = "/"
> >  FILES_${PN}-doc = "${docdir} ${datadir}/common-licenses"
> > --
> > 2.1.0