openstack
/
neutron
Code Issues Proposed changes

Do not check twice IP allocations for auto-address subnets 

For auto-address subnets such as those with SLAAC and DHCP_STATELESS
address modes it is ok to delete them even when there are active IP
allocations.

The current logic might trigger unexpected 409 errors if IP
allocations are made on these subnets concurrently with their
deletion.

This patch simply ensures the final check for active IP allocations is
not performed for this class of subnets; since all IP allocations will
be removed anyway, it does not make sense to check whether there are
allocations at all. In fact, doing this check might cause a failure
of the delete operation if an IP allocation is made concurrently.

This patch also factors out the logic for checking whether there are
IP allocations on the subnet to avoid code duplication.

Closes-Bug: #1414199

Change-Id: I1c4ca6f677845f6e2e8d88f3629c0e91ca73b5d0
This commit is contained in:
Salvatore Orlando 2015-01-23 13:51:15 -08:00
parent 4143763913
commit 939f558226
2 changed files with 27 additions and 15 deletions
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23
neutron/db/db_base_plugin_v2.py
View File

@ -1217,6 +1217,11 @@ class NeutronDbPluginV2(neutron_plugin_base_v2.NeutronPluginBaseV2,
result['allocation_pools'] = new_pools
return result
def _subnet_check_ip_allocations(self, context, subnet_id):
return context.session.query(
models_v2.IPAllocation).filter_by(
subnet_id=subnet_id).join(models_v2.Port).first()
def delete_subnet(self, context, id):
with context.session.begin(subtransactions=True):
subnet = self._get_subnet(context, id)
@ -1236,13 +1241,17 @@ class NeutronDbPluginV2(neutron_plugin_base_v2.NeutronPluginBaseV2,
network_ports = qry_network_ports.all()
if network_ports:
map(context.session.delete, network_ports)
# Check if there are tenant owned ports
tenant_ports = (context.session.query(models_v2.IPAllocation).
filter_by(subnet_id=subnet['id']).
join(models_v2.Port).
filter_by(network_id=subnet['network_id']).first())
if tenant_ports:
raise n_exc.SubnetInUse(subnet_id=id)
# Check if there are more IP allocations, unless
# is_auto_address_subnet is True. In that case the check is
# unnecessary. This additional check not only would be wasteful
# for this class of subnet, but is also error-prone since when
# the isolation level is set to READ COMMITTED allocations made
# concurrently will be returned by this query
if not is_auto_addr_subnet:
if self._subnet_check_ip_allocations(context, id):
LOG.debug("Found IP allocations on subnet %s, "
"cannot delete", id)
raise n_exc.SubnetInUse(subnet_id=id)
context.session.delete(subnet)

19
neutron/plugins/ml2/plugin.py
View File

@ -807,14 +807,17 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
if allocated:
map(session.delete, allocated)
LOG.debug("Ports to auto-deallocate: %s", allocated)
# Check if there are tenant owned ports
tenant_port = (session.query(models_v2.IPAllocation).
filter_by(subnet_id=id).
join(models_v2.Port).
first())
if tenant_port:
LOG.debug("Tenant-owned ports exist")
raise exc.SubnetInUse(subnet_id=id)
# Check if there are more IP allocations, unless
# is_auto_address_subnet is True. In that case the check is
# unnecessary. This additional check not only would be wasteful
# for this class of subnet, but is also error-prone since when
# the isolation level is set to READ COMMITTED allocations made
# concurrently will be returned by this query
if not is_auto_addr_subnet:
if self._subnet_check_ip_allocations(context, id):
LOG.debug("Found IP allocations on subnet %s, "
"cannot delete", id)
raise exc.SubnetInUse(subnet_id=id)
# If allocated is None, then all the IPAllocation were
# correctly deleted during the previous pass.