svn commit: r304594 - head/Mk

[poyopoyo at puripuri.plala.or.jp]

Hi Bryan,

At Fri, 21 Sep 2012 07:58:18 -0500,
Bryan Drewery wrote:
> 
> On 9/21/2012 1:51 AM, poyopoyo at puripuri.plala.or.jp wrote:
> > At Thu, 20 Sep 2012 19:51:30 +0000 (UTC),
> > Beat Gaetzi wrote:
> >>   - Make 'do-package' atomic while creating the pkg file [4]
> > 
> >> Modified: head/Mk/bsd.port.mk
> >> ==============================================================================
> >> @@ -3911,11 +3905,15 @@ do-package: ${TMPPLIST}
> >>  			fi; \
> >>  		fi; \
> >>  	fi
> >> -	@if ${PKG_CMD} -b ${PKGNAME} ${PKGFILE}; then \
> >> +	@TMPPKGFILE=$$(mktemp -t pkg); \
> >> +	trap "${RM} -f $${TMPPKGFILE} $${TMPPKGFILE}${PKG_SUFX}; exit 1" 1 2 3 5 10 13 15; \
> >> +	if ${PKG_CMD} -b ${PKGNAME} $${TMPPKGFILE}; then \
> >> +		${MV} -f $${TMPPKGFILE}${PKG_SUFX} ${PKGFILE}; \
> >>  		if [ -d ${PACKAGES} ]; then \
> >>  			cd ${.CURDIR} && eval ${MAKE} package-links; \
> >>  		fi; \
> >>  	else \
> >> +		${RM} -f $${TMPPKGFILE}; \
> >>  		cd ${.CURDIR} && eval ${MAKE} delete-package; \
> >>  		exit 1; \
> >>  	fi
> > 
> > This does not seem to atomic at all. Well being visible when PKG_SUFX is set.
> 
> How is a single mv(1) on a tempfile not atomic? The purpose here is to
> avoid the very long pkg_create(1) call and avoid leaving an invalid
> package behind on ctrl+c or other interruptions.

Because temporary file which mktemp creates is not referenced by anyone.

> >> +	@TMPPKGFILE=$$(mktemp -t pkg); \

TMPPKGFILE=pkg.XXXXXXXX (here, for example)

> >> +	if ${PKG_CMD} -b ${PKGNAME} $${TMPPKGFILE}; then \
> >> +		${MV} -f $${TMPPKGFILE}${PKG_SUFX} ${PKGFILE}; \

pkg_create creates pkg.XXXXXXXX.tbz and mv it to ${PKGFILE}.
${TMPPKGFILE} left untouched. mv is atomic, but pkg_create does not.
(While mktemp succeed to create pkg.XXXXXXXX, pkg.XXXXXXXX.tbz could be
a symlink, a directory or something fancy)

At Fri, 21 Sep 2012 08:22:37 -0500,
Bryan Drewery wrote:
> I will also try creating the tempfile in the PKGREPOSITORY, to keep it
> on the same filesystem :)

It's nice. I think an easiest way for me to fix this is mktemp -d to
create own temporary directory and pkg_crate ${PKGNAME} under it, then
mv it to ${PKGFILE}. Just a thought, BTW.

-- 
kuro