openstack/devstack
Code Issues Proposed changes

Create global_filter to avoid scan of missing devs

Browse Source 
A while back I added an lvm.conf file with a device filter setting
to try and clean up the LVM hangs in the gate:
  (commit 0b9e76f280)

It turns out this wasn't the real problem, the real problem
is that on an LVS/VGS command LVM  will attempt to open and read
all potential block devices in /dev to see if they have LVM data
on them.  I initially thought the local filter would keep that
from happening, as it turns out the local filter only limits what's
returned AFTER the actual scan process.  In order to keep the scan
from happening at all, either a global_filter needs to be used or
lvmetad needs to be running and enabled.

There are situations in gate tests where /dev/sdX devices are created and
deleted and the result is that we hit situations where LVM tries
to open up devices to check them even if they've been removed.  The
result is we have a blocking open call from LVM that takes approx
60 seconds to time out and fail.

Ubuntu won't have a version of lvmetad until Vivid, so for now
that just leaves the global_filter as an option.

This patch adds the filter routine to the end of stack.sh.  We don't
want to put the routine in lib/cinder_backend/lvm like we had it because
now we have to set the global filter for all LVM commands on the system.
So we put this as one of the last steps in stack.sh and run it if Cinder
is enabled.  This way we can query PV's on the system regardless of what
other services may be running and using LVM and make sure that all of
their devices are added to the filter as well.

Also, make sure we only set this for Ubuntu as Fedora/RHEL variants
utilize lvmetad.

This patch also removes the old change that set the local filter.

DocImpact
Should add this to recommended config for Cinder on systems
that don't have lvmetad, and recommend lvmetad for those that do.

Change-Id: I5d5c48e188cbb9b4208096736807f082bce524e8
Closes-Bug: #1373513
This commit is contained in:
John Griffith 2015-03-17 21:07:39 -06:00
parent 5e159edab3
commit 4bf861c76c
4 changed files with 34 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
lib/cinder
View File

@ -372,15 +372,9 @@ function init_cinder {
if is_service_enabled c-vol && [[ -n "$CINDER_ENABLED_BACKENDS" ]]; then
local be be_name be_type
local has_lvm=0
for be in ${CINDER_ENABLED_BACKENDS//,/ }; do
be_type=${be%%:*}
be_name=${be##*:}
if [[ $be_type == 'lvm' ]]; then
has_lvm=1
fi
if type init_cinder_backend_${be_type} >/dev/null 2>&1; then
# Always init the default volume group for lvm.
if [[ "$be_type" == "lvm" ]]; then
@ -391,17 +385,6 @@ function init_cinder {
done
fi
# Keep it simple, set a marker if there's an LVM backend
# use the created VG's to setup lvm filters
if [[ $has_lvm == 1 ]]; then
# Order matters here, not only obviously to make
# sure the VG's are created, but also some distros
# do some customizations to lvm.conf on init, we
# want to make sure we copy those over
sudo cp /etc/lvm/lvm.conf /etc/cinder/lvm.conf
configure_cinder_backend_conf_lvm
fi
mkdir -p $CINDER_STATE_PATH/volumes
create_cinder_cache_dir
}

31
lib/cinder_backends/lvm
View File

@ -19,7 +19,6 @@
# clean_cinder_backend_lvm - called from clean_cinder()
# configure_cinder_backend_lvm - called from configure_cinder()
# init_cinder_backend_lvm - called from init_cinder()
# configure_cinder_backend_conf_lvm - called from configure_cinder()
# Save trace setting
@ -66,36 +65,6 @@ function init_cinder_backend_lvm {
init_lvm_volume_group $VOLUME_GROUP_NAME-$be_name $VOLUME_BACKING_FILE_SIZE
}
# configure_cinder_backend_conf_lvm - Sets device filter in /etc/cinder/lvm.conf
# init_cinder_backend_lvm
function configure_cinder_backend_conf_lvm {
local filter_suffix='"r/.*/" ]'
local filter_string="filter = [ "
local conf_entries=$(grep volume_group /etc/cinder/cinder.conf | sed "s/ //g")
local pv
local vg
local line
for pv_info in $(sudo pvs --noheadings -o name,vg_name --separator ';'); do
echo_summary "Evaluate PV info for Cinder lvm.conf: $pv_info"
IFS=';' read pv vg <<< "$pv_info"
for line in ${conf_entries}; do
IFS='=' read label group <<< "$line"
group=$(echo $group|sed "s/^ *//g")
if [[ "$vg" == "$group" ]]; then
new="\"a$pv/\", "
filter_string=$filter_string$new
fi
done
done
filter_string=$filter_string$filter_suffix
# FIXME(jdg): Possible odd case that the lvm.conf file has been modified
# and doesn't have a filter entry to search/replace. For devstack don't
# know that we care, but could consider adding a check and add
sudo sed -i "s#^[ \t]*filter.*# $filter_string#g" /etc/cinder/lvm.conf
echo "set LVM filter_strings: $filter_string"
}
# Restore xtrace
$MY_XTRACE

25
lib/lvm
View File

@ -138,6 +138,31 @@ function init_default_lvm_volume_group {
fi
}
# set_lvm_filter() Gather all devices configured for LVM and
# use them to build a global device filter
# set_lvm_filter() Create a device filter
# and add to /etc/lvm.conf. Note this uses
# all current PV's in use by LVM on the
# system to build it's filter.
#
# Usage: set_lvm_filter()
function set_lvm_filter {
local filter_suffix='"r|.*|" ]'
local filter_string="global_filter = [ "
local pv
local vg
local line
for pv_info in $(sudo pvs --noheadings -o name); do
pv=$(echo -e "${pv_info}" | sed 's/ //g' | sed 's/\/dev\///g')
new="\"a|$pv|\", "
filter_string=$filter_string$new
done
filter_string=$filter_string$filter_suffix
sudo sed -i "/# global_filter = \[*\]/a\ $global_filter$filter_string" /etc/lvm/lvm.conf
echo_summary "set lvm.conf device global_filter to: $filter_string"
}
# Restore xtrace
$MY_XTRACE

9
stack.sh
View File

@ -1316,6 +1316,15 @@ service_check
# Prepare bash completion for OSC
openstack complete | sudo tee /etc/bash_completion.d/osc.bash_completion > /dev/null
# If cinder is configured, set global_filter for PV devices
if is_service_enabled cinder; then
if is_ubuntu; then
echo_summary "Configuring lvm.conf global device filter"
set_lvm_filter
else
echo_summary "Skip setting lvm filters for non Ubuntu systems"
fi
fi
# Fin
# ===