Re: [PATCH] isar: Clean mount point on bitbake exit

[Alexander Smirnov <asmirnov@ilbers.de>]

On 02/06/2018 11:31 PM, Jan Kiszka wrote:
> On 2018-02-06 20:55, Alexander Smirnov wrote:
>> 8<--
>>
>> That's it! Branch 'asmirnov/devel', please test and enjoy :-)
>>
>> 8<--
>>
>> Now each multiconfig has registered handler for BuildCompleted event (see
>> class 'isar-event.bbclass'). Moreover, the '/proc/mounts' file contains
>> all the active mounts. In addition, from event handler we could derive
>> all the variables like ${TMPDIR}, ${DISTRO} etc. So it's possible to
>> find all the active mounts for current multiconfig and clean them.
>>
>> NOTE: if build is interrupted by double ^C, some mount points could stay
>> uncleaned. This is caused by remaining processes started by bitbake, for
>> example:
>>   - 'chroot build.sh ...'
>>   - 'multistrap ...'
> 
> Can you explain what the race condition is exactly? It seems to work for
> me so far, no forgotten mounts.

Sometimes after double ^C I see several mounted artifacts in 
buildchroot. But I've also noticed, that there are running processes 
like 'multistrap' and 'build.sh' running *exactly* in this buildchroot.

So, simple test, if you press double ^C and run 'ps ax' after, you will 
likely see running processes. IIRC the same bitbake behavior I saw with 
Yocto, interrupting bitbake doesn't mean to kill the process with 
current task.

Alex

> 
> Jan
> 
>>
>> So please be careful when interrupting build.
>>
>> Signed-off-by: Alexander Smirnov <asmirnov@ilbers.de>
>> ---
>>   meta-isar/recipes-core/images/isar-image-base.bb   | 11 ++++------
>>   meta/classes/dpkg-base.bbclass                     | 12 ++++-------
>>   meta/classes/isar-events.bbclass                   | 15 +++++++++++---
>>   meta/recipes-devtools/buildchroot/buildchroot.bb   | 24 +++++++++-------------
>>   .../buildchroot/files/configscript.sh              |  4 ----
>>   .../buildchroot/files/download_dev-random          | 13 ------------
>>   6 files changed, 30 insertions(+), 49 deletions(-)
>>   delete mode 100644 meta/recipes-devtools/buildchroot/files/download_dev-random
>>
>> diff --git a/meta-isar/recipes-core/images/isar-image-base.bb b/meta-isar/recipes-core/images/isar-image-base.bb
>> index e359ac3..8ddbabb 100644
>> --- a/meta-isar/recipes-core/images/isar-image-base.bb
>> +++ b/meta-isar/recipes-core/images/isar-image-base.bb
>> @@ -55,14 +55,10 @@ do_rootfs() {
>>           -e 's|##ISAR_DISTRO_SUITE##|${DEBDISTRONAME}|g' \
>>              "${WORKDIR}/multistrap.conf.in" > "${WORKDIR}/multistrap.conf"
>>   
>> +    # Do not use bitbake flag [dirs] here because this folder should have
>> +    # specific ownership.
>>       [ ! -d ${IMAGE_ROOTFS}/proc ] && sudo install -d -o 0 -g 0 -m 555 ${IMAGE_ROOTFS}/proc
>>       sudo mount -t proc none ${IMAGE_ROOTFS}/proc
>> -    _do_rootfs_cleanup() {
>> -        ret=$?
>> -        sudo umount ${IMAGE_ROOTFS}/proc 2>/dev/null || true
>> -        (exit $ret) || bb_exit_handler
>> -    }
>> -    trap '_do_rootfs_cleanup' EXIT
>>   
>>       # Create root filesystem. We must use sudo -E here to preserve the environment
>>       # because of proxy settings
>> @@ -72,5 +68,6 @@ do_rootfs() {
>>       sudo chroot ${IMAGE_ROOTFS} /${DISTRO_CONFIG_SCRIPT} ${MACHINE_SERIAL} ${BAUDRATE_TTY} \
>>           ${ROOTFS_DEV}
>>       sudo rm "${IMAGE_ROOTFS}/${DISTRO_CONFIG_SCRIPT}"
>> -    _do_rootfs_cleanup
>> +
>> +    sudo umount ${IMAGE_ROOTFS}/proc 2>/dev/null || true
>>   }
>> diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
>> index 5d5a924..a34c21f 100644
>> --- a/meta/classes/dpkg-base.bbclass
>> +++ b/meta/classes/dpkg-base.bbclass
>> @@ -20,15 +20,11 @@ dpkg_runbuild() {
>>   do_build() {
>>       mkdir -p ${BUILDROOT}
>>       sudo mount --bind ${WORKDIR} ${BUILDROOT}
>> -    _do_build_cleanup() {
>> -        ret=$?
>> -        sudo umount ${BUILDROOT} 2>/dev/null || true
>> -        sudo rmdir ${BUILDROOT} 2>/dev/null || true
>> -        (exit $ret) || bb_exit_handler
>> -    }
>> -    trap '_do_build_cleanup' EXIT
>> +
>>       dpkg_runbuild
>> -    _do_build_cleanup
>> +
>> +    sudo umount ${BUILDROOT} 2>/dev/null || true
>> +    sudo rmdir ${BUILDROOT} 2>/dev/null || true
>>   }
>>   
>>   # Install package to Isar-apt
>> diff --git a/meta/classes/isar-events.bbclass b/meta/classes/isar-events.bbclass
>> index 55fc106..ae0f791 100644
>> --- a/meta/classes/isar-events.bbclass
>> +++ b/meta/classes/isar-events.bbclass
>> @@ -11,10 +11,19 @@ python isar_handler () {
>>       devnull = open(os.devnull, 'w')
>>   
>>       if isinstance(e, bb.event.BuildCompleted):
>> -        bchroot = d.getVar('BUILDCHROOT_DIR', True)
>> +        tmpdir = d.getVar('TMPDIR', True)
>> +        distro = d.getVar('DISTRO', True)
>> +        arch = d.getVar('DISTRO_ARCH', True)
>>   
>> -        # Clean up buildchroot
>> -        subprocess.call('/usr/bin/sudo /bin/umount ' + bchroot + '/isar-apt || /bin/true', stdout=devnull, stderr=devnull, shell=True)
>> +        w = tmpdir + '/work/' + distro + '-' + arch
>> +
>> +        # '/proc/mounts' contains all the active mounts, so knowing 'w' we
>> +        # could get the list of mounts for the specific multiconfig and
>> +        # clean them.
>> +        with open('/proc/mounts', 'rU') as f:
>> +            for line in f:
>> +                if w in line:
>> +                    subprocess.call('sudo umount -f ' + line.split()[1], stdout=devnull, stderr=devnull, shell=True)
>>   
>>       devnull.close()
>>   }
>> diff --git a/meta/recipes-devtools/buildchroot/buildchroot.bb b/meta/recipes-devtools/buildchroot/buildchroot.bb
>> index 304c67e..df9df19 100644
>> --- a/meta/recipes-devtools/buildchroot/buildchroot.bb
>> +++ b/meta/recipes-devtools/buildchroot/buildchroot.bb
>> @@ -12,7 +12,6 @@ FILESPATH =. "${LAYERDIR_core}/recipes-devtools/buildchroot/files:"
>>   SRC_URI = "file://multistrap.conf.in \
>>              file://configscript.sh \
>>              file://setup.sh \
>> -           file://download_dev-random \
>>              file://build.sh"
>>   PV = "1.0"
>>   
>> @@ -32,8 +31,10 @@ BUILDCHROOT_PREINSTALL ?= "gcc \
>>   WORKDIR = "${TMPDIR}/work/${DISTRO}-${DISTRO_ARCH}/${PN}"
>>   
>>   do_build[stamp-extra-info] = "${DISTRO}-${DISTRO_ARCH}"
>> -do_build[dirs] = "${WORKDIR}/hooks_multistrap \
>> -                  ${BUILDCHROOT_DIR}/isar-apt"
>> +do_build[dirs] = "${BUILDCHROOT_DIR}/isar-apt \
>> +                  ${BUILDCHROOT_DIR}/dev \
>> +                  ${BUILDCHROOT_DIR}/proc \
>> +                  ${BUILDCHROOT_DIR}/sys"
>>   do_build[depends] = "isar-apt:do_cache_config"
>>   
>>   do_build() {
>> @@ -41,7 +42,6 @@ do_build() {
>>   
>>       chmod +x "${WORKDIR}/setup.sh"
>>       chmod +x "${WORKDIR}/configscript.sh"
>> -    install -m 755 "${WORKDIR}/download_dev-random" "${WORKDIR}/hooks_multistrap/"
>>   
>>       # Multistrap accepts only relative path in configuration files, so get it:
>>       cd ${TOPDIR}
>> @@ -60,15 +60,6 @@ do_build() {
>>           -e 's|##DIR_HOOKS##|./'"$WORKDIR_REL"'/hooks_multistrap|g' \
>>              "${WORKDIR}/multistrap.conf.in" > "${WORKDIR}/multistrap.conf"
>>   
>> -    [ ! -d ${BUILDCHROOT_DIR}/proc ] && install -d -m 555 ${BUILDCHROOT_DIR}/proc
>> -    sudo mount -t proc none ${BUILDCHROOT_DIR}/proc
>> -    _do_build_cleanup() {
>> -        ret=$?
>> -        sudo umount ${BUILDCHROOT_DIR}/proc 2>/dev/null || true
>> -        (exit $ret) || bb_exit_handler
>> -    }
>> -    trap '_do_build_cleanup' EXIT
>> -
>>       do_setup_mounts
>>   
>>       # Create root filesystem
>> @@ -79,7 +70,6 @@ do_build() {
>>   
>>       # Configure root filesystem
>>       sudo chroot ${BUILDCHROOT_DIR} /configscript.sh
>> -    _do_build_cleanup
>>   
>>       do_cleanup_mounts
>>   }
>> @@ -96,10 +86,16 @@ do_setup_mounts[stamp-extra-info] = "${DISTRO}-${DISTRO_ARCH}"
>>   
>>   do_setup_mounts() {
>>       sudo mount --bind ${DEPLOY_DIR_APT}/${DISTRO} ${BUILDCHROOT_DIR}/isar-apt
>> +    sudo mount --bind /dev ${BUILDCHROOT_DIR}/dev
>> +    sudo mount -t proc none ${BUILDCHROOT_DIR}/proc
>> +    sudo mount -t sysfs none ${BUILDCHROOT_DIR}/sys
>>   }
>>   
>>   addtask setup_mounts after do_build
>>   
>>   do_cleanup_mounts() {
>>       sudo umount ${BUILDCHROOT_DIR}/isar-apt 2>/dev/null || true
>> +    sudo umount ${BUILDCHROOT_DIR}/dev 2>/dev/null || true
>> +    sudo umount ${BUILDCHROOT_DIR}/proc 2>/dev/null || true
>> +    sudo umount ${BUILDCHROOT_DIR}/sys 2>/dev/null || true
>>   }
>> diff --git a/meta/recipes-devtools/buildchroot/files/configscript.sh b/meta/recipes-devtools/buildchroot/files/configscript.sh
>> index 9813c9a..524e50c 100644
>> --- a/meta/recipes-devtools/buildchroot/files/configscript.sh
>> +++ b/meta/recipes-devtools/buildchroot/files/configscript.sh
>> @@ -39,10 +39,6 @@ export LC_ALL=C LANGUAGE=C LANG=C
>>   #run pre installation script
>>   /var/lib/dpkg/info/dash.preinst install
>>   
>> -# apt-get http method, gpg require /dev/null
>> -mount -t devtmpfs -o mode=0755,nosuid devtmpfs /dev
>> -
>>   #configuring packages
>>   dpkg --configure -a
>>   apt-get update
>> -umount /dev
>> diff --git a/meta/recipes-devtools/buildchroot/files/download_dev-random b/meta/recipes-devtools/buildchroot/files/download_dev-random
>> deleted file mode 100644
>> index 5b5b96b..0000000
>> --- a/meta/recipes-devtools/buildchroot/files/download_dev-random
>> +++ /dev/null
>> @@ -1,13 +0,0 @@
>> -#!/bin/sh
>> -
>> -set -e
>> -
>> -readonly ROOTFS="$1"
>> -
>> -mknod "${ROOTFS}/dev/random" c 1 8
>> -chmod 640 "${ROOTFS}/dev/random"
>> -chown 0:0 "${ROOTFS}/dev/random"
>> -
>> -mknod "${ROOTFS}/dev/urandom" c 1 9
>> -chmod 640 "${ROOTFS}/dev/urandom"
>> -chown 0:0 "${ROOTFS}/dev/urandom"
>>
> 

-- 
With best regards,
Alexander Smirnov

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