openstack
/
cinder
Code Issues Proposed changes

Brick LVM: Optimize get_volume 

When we only want the LV information for a single volume, call
"lvs" with the volume name specified.

This should reduce unnecessary load of calling "lvs" for the
whole VG.

Related-Bug: #1373513

Change-Id: Ifbb679e9160f44fe52ecba7bf19aa0eb5bb133f1
This commit is contained in:
Eric Harney 2014-10-23 11:28:29 -04:00
parent 90d7c0c2b3
commit dcda67053d
1 changed files with 9 additions and 5 deletions
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14
cinder/brick/local_dev/lvm.py
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@ -233,7 +233,7 @@ class LVM(executor.Executor):
return self._supports_lvchange_ignoreskipactivation
@staticmethod
def get_all_volumes(root_helper, vg_name=None):
def get_all_volumes(root_helper, vg_name=None, lv_name=None):
"""Static method to get all LV's on a system.
:param root_helper: root_helper to use for execute
@ -245,7 +245,9 @@ class LVM(executor.Executor):
cmd = ['env', 'LC_ALL=C', 'lvs', '--noheadings', '--unit=g',
'-o', 'vg_name,name,size', '--nosuffix']
if vg_name is not None:
if lv_name is not None and vg_name is not None:
cmd.append("%s/%s" % (vg_name, lv_name))
elif vg_name is not None:
cmd.append(vg_name)
lvs_start = time.time()
@ -265,13 +267,15 @@ class LVM(executor.Executor):
return lv_list
def get_volumes(self):
def get_volumes(self, lv_name=None):
"""Get all LV's associated with this instantiation (VG).
:returns: List of Dictionaries with LV info
"""
self.lv_list = self.get_all_volumes(self._root_helper, self.vg_name)
self.lv_list = self.get_all_volumes(self._root_helper,
self.vg_name,
lv_name)
return self.lv_list
def get_volume(self, name):
@ -280,7 +284,7 @@ class LVM(executor.Executor):
:returns: dict representation of Logical Volume if exists
"""
ref_list = self.get_volumes()
ref_list = self.get_volumes(name)
for r in ref_list:
if r['name'] == name:
return r