From 203b974cdde83e876ba665df47928868278581ae Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Sat, 2 Oct 2021 23:25:41 -0400 Subject: make file updates atomic While we have locks against other invocations of build-docbook-catalog to keep them from clobbering each other (write locks), we didn't have any locks for users of the databases (read locks). Rewriting the files in place causes those readers to get partially written files and then fail (due to missing entries). Closes: https://bugs.gentoo.org/773517 Signed-off-by: Mike Frysinger --- build-docbook-catalog | 51 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 20 deletions(-) diff --git a/build-docbook-catalog b/build-docbook-catalog index 017ae75..b420541 100755 --- a/build-docbook-catalog +++ b/build-docbook-catalog @@ -84,8 +84,8 @@ main() { # Clean out old dtds from catalog verb "Cleaning out old DocBook XML versions from ${CATALOG} and ${ROOTCATALOG}" - clean_catalog "${DOCBOOKDIR}/xml\(-simple\)*-dtd-[^/\"']*/[^/\"']*" "${CATALOG}" - clean_catalog "${DOCBOOKDIR}/xml\(-simple\)*-dtd-[^/\"']*/[^/\"']*" "${ROOTCATALOG}" + clean_catalog "${DOCBOOKDIR}/xml\(-simple\)*-dtd-[^/\"']*/[^/\"']*" "${CATALOG}.tmp" + clean_catalog "${DOCBOOKDIR}/xml\(-simple\)*-dtd-[^/\"']*/[^/\"']*" "${ROOTCATALOG}.tmp" if set_dtds; then for d in "${DTDS[@]}"; do @@ -97,6 +97,14 @@ main() { populate_entities fi + sed -i \ + -e "s:${ROOTCATALOG}\.tmp:${ROOTCATALOG}:g" \ + -e "s:${CATALOG}\.tmp:${CATALOG}:g" \ + "${ROOT}${ROOTCATALOG}.tmp" \ + "${ROOT}${CATALOG}.tmp" || error "could not clean up" + mv "${ROOT}${ROOTCATALOG}.tmp" "${ROOT}${ROOTCATALOG}" + mv "${ROOT}${CATALOG}.tmp" "${ROOT}${CATALOG}" + # NB: Don't delete the lock since we can't delete files by fd, and if we do # it by path, we might delete the lock while other processes grab it. ) 200>>"${lock}" @@ -173,11 +181,13 @@ create_catalogs() { if [[ ! -r ${ROOT}${ROOTCATALOG} ]] ; then error "failed creating ${ROOTCATALOG}" fi + cp "${ROOT}${ROOTCATALOG}" "${ROOT}${ROOTCATALOG}.tmp" else verb "Found XML Catalog root ${ROOTCATALOG}" # clean out existing entries verb " Cleaning existing ${CATALOG} delegates from ${ROOTCATALOG}" - clean_catalog "file://${CATALOG}" "${ROOTCATALOG}" + cp "${ROOTCATALOG}" "${ROOTCATALOG}.tmp" + clean_catalog "file://${CATALOG}" "${ROOTCATALOG}.tmp" fi # Initialize catalogs if they don't exist or are corrupt. @@ -194,24 +204,25 @@ create_catalogs() { else verb "Found DocBook XML Catalog ${CATALOG}" fi + cp "${ROOT}${CATALOG}" "${ROOT}${CATALOG}.tmp" # dtd pointers verb " Populating ${ROOTCATALOG} with DTD delegates to ${CATALOG}" adds=( - "delegatePublic" "-//OASIS//ENTITIES DocBook" "${CATALOG}" - "delegatePublic" "-//OASIS//ELEMENTS DocBook" "${CATALOG}" - "delegatePublic" "-//OASIS//DTD DocBook" "${CATALOG}" - "delegateSystem" "http://www.oasis-open.org/docbook/" "${CATALOG}" - "delegateURI" "http://www.oasis-open.org/docbook/" "${CATALOG}" + "delegatePublic" "-//OASIS//ENTITIES DocBook" "${CATALOG}.tmp" + "delegatePublic" "-//OASIS//ELEMENTS DocBook" "${CATALOG}.tmp" + "delegatePublic" "-//OASIS//DTD DocBook" "${CATALOG}.tmp" + "delegateSystem" "http://www.oasis-open.org/docbook/" "${CATALOG}.tmp" + "delegateURI" "http://www.oasis-open.org/docbook/" "${CATALOG}.tmp" ) - multi_xmlcatalog_add "${ROOTCATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${ROOTCATALOG}.tmp" "${adds[@]}" # entities pointer verb " Populating ${ROOTCATALOG} with ISO entities delegate to ${CATALOG}" adds=( - "delegatePublic" "ISO 8879:1986" "${CATALOG}" + "delegatePublic" "ISO 8879:1986" "${CATALOG}.tmp" ) - multi_xmlcatalog_add "${ROOTCATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${ROOTCATALOG}.tmp" "${adds[@]}" } # @@ -259,7 +270,7 @@ populate_dtd() { "rewriteSystem" "http://www.oasis-open.org/docbook/xml/${v}" "${docbookdir}" "rewriteURI" "http://www.oasis-open.org/docbook/xml/${v}" "${docbookdir}" ) - multi_xmlcatalog_add "${CATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${CATALOG}.tmp" "${adds[@]}" # grab the RCS date from docbookx.dtd for comparison purposes if [[ ! -f ${ROOT}${docbookdir}/ent/iso-lat1.ent ]]; then @@ -305,7 +316,7 @@ populate_simple_dtd() { "rewriteSystem" "http://www.oasis-open.org/docbook/xml/simple/${v}" "${docbookdir}" "rewriteURI" "http://www.oasis-open.org/docbook/xml/simple/${v}" "${docbookdir}" ) - multi_xmlcatalog_add "${CATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${CATALOG}.tmp" "${adds[@]}" } # @@ -367,7 +378,7 @@ populate_entities() { : $(( i += 2 )) elif [[ ${entities[i]} == "${avail[j]}" ]]; then xmlcatalog --noout --add "public" "${entities[i+1]}" \ - "file://${isodir}/${entities[i]}" "${ROOT}${CATALOG}" + "file://${isodir}/${entities[i]}" "${ROOT}${CATALOG}.tmp" : $(( j += 1 )) : $(( i += 2 )) else @@ -386,8 +397,8 @@ populate_xsl() { local type=$1 # Delete current entries from the catalog (delete legacy versioned entries too) - clean_catalog "${DOCBOOKDIR}/${type}-stylesheets(-[0-9\.]+)?" "${CATALOG}" - clean_catalog "${DOCBOOKDIR}/${type}-stylesheets(-[0-9\.]+)?" "${ROOTCATALOG}" + clean_catalog "${DOCBOOKDIR}/${type}-stylesheets(-[0-9\.]+)?" "${CATALOG}.tmp" + clean_catalog "${DOCBOOKDIR}/${type}-stylesheets(-[0-9\.]+)?" "${ROOTCATALOG}.tmp" local xsldir=${DOCBOOKDIR}/${type}-stylesheets @@ -406,17 +417,17 @@ populate_xsl() { verb " Populating ${ROOTCATALOG} with XSL delegations" adds=( - "delegateSystem" "http://docbook.sourceforge.net/release/${type}/" "${CATALOG}" - "delegateURI" "http://docbook.sourceforge.net/release/${type}/" "${CATALOG}" + "delegateSystem" "http://docbook.sourceforge.net/release/${type}/" "${CATALOG}.tmp" + "delegateURI" "http://docbook.sourceforge.net/release/${type}/" "${CATALOG}.tmp" ) - multi_xmlcatalog_add "${ROOTCATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${ROOTCATALOG}.tmp" "${adds[@]}" verb " Populating ${CATALOG} with XSL stylesheets" adds=( "rewriteSystem" "http://docbook.sourceforge.net/release/${type}/current" "${xsldir}" "rewriteURI" "http://docbook.sourceforge.net/release/${type}/current" "${xsldir}" ) - multi_xmlcatalog_add "${CATALOG}" "${adds[@]}" + multi_xmlcatalog_add "${CATALOG}.tmp" "${adds[@]}" } # Call the main routine -- cgit v1.2.3-65-gdbad