Adding new ansible module lvol_cache

lib/ansible/modules/extras/system/lvol_cache.py

@@ -0,0 +1,793 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2016, Pavol Ipoth <pavol.ipoth@gmail.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+DOCUMENTATION = '''
+---
+author:
+    - "Pavol Ipoth <pavol.ipoth@gmail.com>"
+module: lvol_cache
+short_description: Configure Cache LVM logical volumes
+description:
+  - This module creates, removes or resizes, converts cache logical volumes.
+options:
+  vg:
+    description:
+    - The volume group this logical volume is part of.
+    required: true
+  lv:
+    description:
+    - The name of the logical volume.
+    required: true
+  size:
+    description:
+    - The size of the logical volume, by
+      default in megabytes or optionally with one of [bBsSkKmMgGtTpPeE] units; or
+      as a percentage of [VG|PVS|FREE]; +size is not implemented, as it is by
+      design not indempodent
+      Float values must begin with a digit.
+  state:
+    choices: [ "present", "absent" ]
+    default: present
+    description:
+    - Control if the logical volume exists. If C(present) the C(size) option
+      is required.
+    required: false
+  force:
+    choices: [ "yes", "no" ]
+    default: "no"
+    description:
+    - Shrink/extend/remove/conversion operations of volumes requires this switch. Ensures that
+      that filesystems get never corrupted/destroyed by mistake.
+    required: false
+  opts:
+    description:
+    - Free-form options to be passed to the lvcreate command
+  pvs:
+    description:
+    - Comma separated list of physical volumes /dev/sda,/dev/sdc
+  type:
+    choices: ["cache", "cache-pool", "normal"]
+    default: normal
+    description:
+    - Type of logical volume, cache is cached lvol, cache-pool is cache pool
+      supplying cached lvol, normal is lvol without any type. To create cache
+      lvol, cache pool must already exist
+  mode:
+    choices: ["writeback", "writethrough"]
+    default: writethrough
+    - This value is used when type is cache pool, specifies how data
+      are written to the lvol
+  pool:
+    description:
+    - This value is used when type is cache, specifies which cache pool will
+      be caching data for cache lvol. Must be in format vg/lv. Cache pool lvol
+      and cache lvol must be from same vg (this is restriction of lvm2).
+notes:
+  - Filesystems on top of the volume are not resized.
+'''
+
+EXAMPLES = '''
+# Create a logical volume of 512m.
+- lvol: vg=firefly lv=test size=512m
+
+# Create a logical volume of 512g.
+- lvol: vg=firefly lv=test size=512g
+
+# Create a logical volume the size of all remaining space in the volume group
+- lvol: vg=firefly lv=test size=100%FREE
+
+# Create a logical volume with special options
+- lvol: vg=firefly lv=test size=512g opts="-r 16"
+
+# Extend the logical volume to 1024m.
+- lvol: vg=firefly lv=test size=1024m
+
+# Extend the logical volume to take all remaining space of the PVs
+- lvol: vg=firefly lv=test size=100%PVS
+
+# Resize the logical volume to % of VG
+- lvol: vg=firefly lv=test size=80%VG force=yes
+
+# Reduce the logical volume to 512m
+- lvol: vg=firefly lv=test size=512m force=yes
+
+# Remove the logical volume.
+- lvol: vg=firefly lv=test state=absent force=yes
+
+# Create cache pool logical volume of 512m.
+- lvol: vg=firefly lv=testpool size=512m type=cache-pool
+
+# Create cache lvol testcached with cache pool firefly/testpool,
+# cache pool must already exist
+- lvol: vg=firefly lv=testcached size=1g type=cache pool=firefly/testpool
+
+# Extend cache pool to 2g, force must be yes
+- lvol: vg=firefly lv=testpool size=2g type=cache-pool force=yes
+
+# Extend cache lvol to 5g, force must be yes
+- lvol: vg=firefly lv=testcached size=5g type=cache pool=firefly/testpool force=yes
+
+# Convert cache lvol to normal lvol
+- lvol: vg=firefly lv=testcached size=5g type=normal force=yes
+
+# Convert normal lvol to cache pool
+- lvol: vg=firefly lv=testcached size=5g type=cache-pool force=yes
+
+# Convert cache pool lvol to cache lvol, you should notice that firefly/testpool
+# still exists
+- lvol: vg=firefly lv=testcached size=5g type=cache pool=firefly/testpool force=yes
+
+# Remove cache pool lvol, this also changes cache lvol to normal
+- lvol: vg=firefly lv=testpool size=2g type=cache-pool state=absent force=yes
+'''
+
+import re
+# import module snippets
+from ansible.module_utils.basic import *
+
+decimal_point = re.compile(r"(\d+\.?\d+)")
+
+class Vg(object):
+
+    name = ''
+    size = None
+    unit = 'm'
+    free = None
+    vg_extent_size = None
+    module = None
+
+    def __init__(self, module, vg_name, unit):
+        self.module = module
+        vg_info = self.get_vg_info(vg_name, unit)
+
+        self.name = vg_info['name']
+        self.size = vg_info['size']
+        self.unit = unit
+        self.free = vg_info['free']
+        self.vg_extent_size = vg_info['vg_extent_size']
+
+    def get_vg_info(self, vg_name, unit):
+        vgs_cmd = self.module.get_bin_path("vgs", required=True)
+        cmd = "%s --noheadings -o vg_name,size,free,vg_extent_size --units %s --separator ';' %s" % (vgs_cmd, unit, vg_name)
+
+        rc, current_vgs, err = self.module.run_command(cmd)
+
+        if rc != 0:
+            self.module.fail_json(msg="Volume group %s does not exist." % vg_name, rc=rc, err=err)
+
+        parts = current_vgs.strip().split(';')
+
+        return {
+            'name': parts[0],
+            'size': float(decimal_point.match(parts[1]).group(1)),
+            'free': float(decimal_point.match(parts[2]).group(1)),
+            'vg_extent_size': float(decimal_point.match(parts[3]).group(1))
+        }
+
+class Lvol(object):
+
+    name = ''
+    size = None
+    unit = 'm'
+    pool_lv = ''
+    vg = None
+    yes_opt = ""
+    cachemode = ""
+    module = None
+
+    def __init__(self, module, vg_name, lv_name, unit):
+        self.vg = Vg(module, vg_name, unit)
+        self.module = module
+
+        lv_info = self.get_lv_info(vg_name, lv_name, unit)
+
+        self.name = lv_info['name']
+        self.pool_lv = lv_info['pool_lv']
+        self.size = lv_info['size']
+        self.cachemode = lv_info['cachemode']
+        self.unit = unit
+
+        self.yes_opt = self.get_yes_opt(module)
+
+    @classmethod
+    def exists(cls, module, vg_name, lv_name):
+        exists = False
+        lvs_cmd = module.get_bin_path("lvs", required=True)
+
+        rc, current_lv, err = module.run_command(
+            "%s -a %s/%s" % (lvs_cmd, vg_name, lv_name)
+        )
+
+        if rc == 0:
+            exists = True
+        elif rc == 5 and "Failed to find logical volume" in err:
+            exists = False
+        else:
+            module.fail_json(msg="Unexpected error", rc=rc, err=err)
+
+        return exists
+
+    @classmethod
+    def is_cache_pool(cls, module, vg_name, lv_name):
+        is_cache_pool = False
+        lvs_cmd = module.get_bin_path("lvs", required=True)
+
+        rc, current_lv, err = module.run_command(
+            "%s -a --noheadings --nosuffix -o lv_layout --separator ';' %s/%s" % (lvs_cmd, vg_name, lv_name)
+        )
+
+        if rc != 0:
+            module.fail_json(msg="Error", rc=rc, err=err)
+
+        parts = current_lv.strip().split(';')
+
+        if 'cache,pool' in parts[0]:
+            is_cache_pool = True
+
+        return is_cache_pool
+
+    @classmethod
+    def is_cache_lv(cls, module, vg_name, lv_name):
+        is_cache_lv = False
+        lvs_cmd = module.get_bin_path("lvs", required=True)
+
+        rc, current_lv, err = module.run_command(
+            "%s -a --noheadings --nosuffix -o lv_layout --separator ';' %s/%s" % (lvs_cmd, vg_name, lv_name)
+        )
+
+        if rc != 0:
+            module.fail_json(msg="Error", rc=rc, err=err)
+
+        parts = current_lv.strip().split(';')
+
+        if 'cache' in parts[0] and 'pool' not in parts[0]:
+            is_cache_lv = True
+
+        return is_cache_lv
+
+    @classmethod
+    def mkversion(cls, major, minor, patch):
+        return (1000 * 1000 * int(major)) + (1000 * int(minor)) + int(patch)
+
+    @classmethod
+    def get_lvm_version(cls, module):
+        ver_cmd = module.get_bin_path("lvm", required=True)
+        rc, out, err = module.run_command("%s version" % (ver_cmd))
+
+        if rc != 0:
+            return None
+
+        m = re.search("LVM version:\s+(\d+)\.(\d+)\.(\d+).*(\d{4}-\d{2}-\d{2})", out)
+
+        if not m:
+            return None
+
+        return cls.mkversion(m.group(1), m.group(2), m.group(3))
+
+    def get_lv_info(self, vg_name, lv_name, unit):
+        lvs_cmd = self.module.get_bin_path("lvs", required=True)
+
+        rc, current_lvs, err = self.module.run_command(
+            "%s -a --noheadings --nosuffix -o lv_name,size,pool_lv,cachemode --units %s --separator ';' %s/%s" % (lvs_cmd, unit, vg_name, lv_name)
+        )
+
+        if rc != 0:
+            self.module.fail_json(msg="Volume group or lvol does not exist." % vg_name, rc=rc, err=err)
+
+        parts = current_lvs.strip().split(';')
+
+        return {
+            'name': parts[0].replace('[','').replace(']',''),
+            'size': float(decimal_point.match(parts[1]).group(1)),
+            'pool_lv': parts[2].replace('[','').replace(']',''),
+            'cachemode': parts[3]
+        }
+
+    @classmethod
+    def get_yes_opt(cls, module):
+        # Determine if the "--yes" option should be used
+        version_found = cls.get_lvm_version(module)
+
+        if version_found == None:
+            module.fail_json(msg="Failed to get LVM version number")
+
+        version_yesopt = cls.mkversion(2, 2, 99) # First LVM with the "--yes" option
+
+        if version_found >= version_yesopt:
+            yesopt = "--yes"
+        else:
+            yesopt = ""
+
+        return yesopt
+
+    @classmethod
+    def get_size_opt(cls, requested_size):
+        if '%' in requested_size:
+            return 'l'
+        else:
+            return 'L'
+
+    @classmethod
+    def calculate_size(cls, vg_free, vg_size, lv_size, size):
+        if '%' in size:
+            parts = size.split('%', 1)
+            size_percent = parts[0]
+
+            size_whole = parts[1]
+
+            if size_whole == 'VG' or size_whole == 'PVS':
+               size_requested = float(size_percent) * float(vg_size) / 100
+            else: # size_whole == 'FREE':
+               size_requested = float(size_percent) * float(vg_free) / 100
+
+            if '+' in size:
+               size_requested += float(lv_size)
+        else:
+            size_requested = float(size[0:-1])
+
+            if '+' in size:
+               size_requested += float(lv_size)
+
+        return size_requested
+
+    @classmethod
+    def create_lv(cls, module, requested_size, unit, opts, vg_name, lv_name, pvs):
+        yes_opt = cls.get_yes_opt(module)
+
+        lvcreate_cmd = module.get_bin_path("lvcreate", required=True)
+
+        cmd = "%s %s -n %s -L %s%s %s %s %s" % (lvcreate_cmd, yes_opt, lv_name, requested_size, unit, opts, vg_name, pvs)
+
+        rc, _, err = module.run_command(cmd)
+
+        if rc != 0:
+            module.fail_json(msg="Creating logical volume '%s' failed" % lv_name, rc=rc, err=err)
+
+    @classmethod
+    def delete_lv(cls, module, force, vg_name, lv_name):
+        if not force:
+            module.fail_json(msg="Sorry, no removal of logical volume %s without force=yes." % (lv_name))
+
+        lvremove_cmd = module.get_bin_path("lvremove", required=True)
+        rc, _, err = module.run_command("%s --force %s/%s" % (lvremove_cmd, vg_name, lv_name))
+
+        if rc !=0 :
+            module.fail_json(msg="Failed to remove logical volume %s/%s" % (vg_name, lv_name), rc=rc, err=err)
+
+    def resize_common(self, tool, requested_size, pvs):
+        cmd = "%s -L %s%s %s/%s %s" % (tool, requested_size, self.unit, self.vg.name, self.name, pvs)
+
+        rc, out, err = self.module.run_command(cmd)
+
+        if rc != 0:
+            if "Reached maximum COW size" in out:
+                self.module.fail_json(msg="Unable to resize %s to %s%s" % (self.name, requested_size, self.unit), rc=rc, err=err, out=out)
+            elif "matches existing size" in err:
+                self.module.exit_json(changed=False, vg=self.vg.name, lv=self.name, size=self.size)
+            else:
+                self.module.fail_json(msg="Unable to resize %s to %s%s" % (self.name, requested_size, self.unit), rc=rc, err=err)
+
+    def shrink_lv(self, force, requested_size, pvs):
+        if requested_size == 0:
+            self.module.fail_json(msg="Sorry, no shrinking of %s to 0 permitted." % (self.name))
+        elif not force:
+            self.module.fail_json(msg="Sorry, no shrinking of %s without force=yes" % (self.name))
+        else:
+            tool = self.module.get_bin_path("lvreduce", required=True)
+            tool = '%s %s' % (tool, '--force')
+
+        self.resize_common(tool, requested_size, pvs)
+
+    def extend_lv(self, requested_size, pvs):
+        if (self.vg.free > 0)  and self.vg.free >= (requested_size - self.size):
+            tool = self.module.get_bin_path("lvextend", required=True)
+        else:
+            self.module.fail_json(
+                msg="Logical Volume %s could not be extended. Not enough free space left (%s%s required / %s%s available)"
+                % (self.name, (requested_size -  self.size), self.unit, self.vg.free, self.unit)
+            )
+
+        self.resize_common(tool, requested_size, pvs)
+
+    def resize_lv(self, force, requested_size, pvs):
+        if self.size < requested_size:
+            self.extend_lv(requested_size, pvs)
+        elif self.size > requested_size + self.vg.vg_extent_size:  # more than an extent too large
+            self.shrink_lv(force, requested_size, pvs)
+
+        self.__init__(self.module, self.vg.name, self.name, self.unit)
+
+    def convert_to_cache(self, pool):
+        lvconvert_cmd = self.module.get_bin_path("lvconvert", required=True)
+
+        rc, out, err = self.module.run_command(
+            "%s --type cache --cachepool %s %s/%s" % (lvconvert_cmd, pool, self.vg.name, self.name)
+        )
+
+        if rc != 0:
+            self.module.fail_json(msg="Converting logical volume to cache LV '%s' failed" % self.name, rc=rc, err=err)
+
+        return CacheLvol(self.module, self.vg.name, self.name, self.unit)
+
+    def convert_to_cache_pool(self, force, mode):
+        lvconvert_cmd = self.module.get_bin_path("lvconvert", required=True)
+        yes_opt = self.get_yes_opt(self.module)
+
+        if not force:
+            self.module.fail_json(msg="Sorry, no conversion of %s to cache-pool without force=yes." % (self.name))
+
+        rc, out, err = self.module.run_command(
+            "%s %s --type cache-pool --cachemode %s %s/%s" % (lvconvert_cmd, yes_opt, mode, self.vg.name, self.name)
+        )
+
+        if rc != 0:
+            self.module.fail_json(msg="Converting logical volume to cache pool '%s' failed" % self.name, rc=rc, err=err)
+
+        return CachePoolLvol(self.module, self.vg.name, self.name, self.unit)
+
+class CachePoolLvol(Lvol):
+
+    @classmethod
+    def create_lv(cls, module, requested_size, unit, opts, vg_name, lv_name, pvs, mode):
+        opts += " --type cache-pool --cachemode %s" % (mode)
+        super(CachePoolLvol, cls).create_lv(module, requested_size, unit, opts, vg_name, lv_name, pvs)
+
+    def get_cache_lvol_name(self):
+        cache_lvol_info = None
+        lvs_cmd = self.module.get_bin_path("lvs", required=True)
+
+        rc, current_lvs, err = self.module.run_command(
+            "%s -a --noheadings --nosuffix -o lv_name,size,pool_lv --units %s --separator ';' %s" % (lvs_cmd, self.unit, self.vg.name))
+
+        if rc != 0:
+            if state == 'absent':
+                self.module.exit_json(changed=False, stdout="Volume group %s does not exist." % self.vg.name, stderr=False)
+            else:
+                self.module.fail_json(msg="Volume group %s does not exist." % self.vg.name, rc=rc, err=err)
+
+        for line in current_lvs.splitlines():
+            parts = line.strip().split(';')
+            pool = parts[2].replace('[','').replace(']','')
+
+            if pool == self.name:
+                cache_lvol_info = parts[0].replace('[','').replace(']','')
+
+        return cache_lvol_info
+
+    def resize_lv(self, force, requested_size, pvs):
+        parent_cache_lvol_name = self.get_cache_lvol_name()
+
+        self.delete_lv(self.module, force, self.vg.name, self.name)
+        self.create_lv(self.module, requested_size, self.unit, '', self.vg.name, self.name, pvs, self.cachemode)
+
+        if parent_cache_lvol_name is not None:
+            parent_cache_lvol = Lvol(self.module, self.vg.name, parent_cache_lvol_name, self.unit)
+            parent_cache_lvol.convert_to_cache("%s/%s" % (self.vg.name, self.name))
+
+        self.__init__(self.module, self.vg.name, self.name, self.unit)
+
+    def convert_to_cache(self, force, opts, pvs, pool):
+        self.delete_lv(self.module, force, self.vg.name, self.name)
+        CacheLvol.create_lv(self.module, self.size, self.unit, opts, self.vg.name, self.name, pvs, pool)
+
+        return CacheLvol(self.module, self.vg.name, self.name, self.unit)
+
+    def convert_to_normal(self, force, opts, pvs):
+        self.delete_lv(self.module, force, self.vg.name, self.name)
+        Lvol.create_lv(self.module, self.size, self.unit, opts, self.vg.name, self.name, pvs)
+
+        return Lvol(self.module, self.vg.name, self.name, self.unit)
+
+    def change_mode(self, force, opts, pvs, mode):
+        cache_lvol_name = self.get_cache_lvol_name()
+
+        self.delete_lv(self.module, force, self.vg.name, self.name)
+        self.create_lv(self.module, self.size, self.unit, opts, self.vg.name, self.name, pvs, mode)
+
+        if cache_lvol_name is not None:
+            lvol = Lvol(self.module, self.vg.name, cache_lvol_name, self.unit)
+            lvol.convert_to_cache("%s/%s" % (self.vg.name, self.name))
+
+        self.__init__(self.module, self.vg.name, self.name, self.unit)
+
+class CacheLvol(Lvol):
+
+    @classmethod
+    def create_lv(cls, module, requested_size, unit, opts, vg_name, lv_name, pvs, pool):
+        opts += " --type cache --cachepool %s" % (pool)
+        super(CacheLvol, cls).create_lv(module, requested_size, unit, opts, vg_name, lv_name, pvs)
+
+    def shrink_cache_lv(self, force, requested_size, pvs):
+        self.split_cache_lv()
+        self.shrink_lv(force, requested_size, pvs)
+        self.attach_cache_lv()
+
+    def extend_cache_lv(self, requested_size, pvs):
+        self.split_cache_lv()
+        self.extend_lv(requested_size, pvs)
+        self.attach_cache_lv()
+
+    def convert_to_normal(self):
+        lvconvert_cmd = self.module.get_bin_path("lvconvert", required=True)
+        lvsplit_cmd = "%s --splitcache %s/%s" % (lvconvert_cmd, self.vg.name, self.name)
+
+        rc, _, err = self.module.run_command(lvsplit_cmd)
+
+        if rc != 0:
+            self.module.fail_json(msg="Spliting cache from logical volume '%s' failed" % self.name, rc=rc, err=err)
+
+        return Lvol(self.module, self.vg.name, self.name, self.unit)
+
+    def split_cache_lv(self):
+        lvconvert_cmd = self.module.get_bin_path("lvconvert", required=True)
+        lvsplit_cmd = "%s --splitcache %s/%s" % (lvconvert_cmd, self.vg.name, self.name)
+
+        rc, _, err = self.module.run_command(lvsplit_cmd)
+
+        if rc != 0:
+            self.module.fail_json(msg="Spliting cache from logical volume '%s' failed" % self.name, rc=rc, err=err)
+
+    def attach_cache_lv(self):
+        lvconvert_cmd = self.module.get_bin_path("lvconvert", required=True)
+        lvattach_cmd = "%s --type cache --cachepool %s %s/%s" % (lvconvert_cmd, self.pool_lv, self.vg.name, self.name)
+
+        rc, _, err = self.module.run_command(lvattach_cmd)
+
+        if rc != 0:
+            self.module.fail_json(msg="Attaching cache %s to logical volume %s failed" % (self.pool_lv, self.name), rc=rc, err=err)
+
+    def resize_lv(self, force, requested_size, pvs):
+        if self.size < requested_size:
+            self.extend_cache_lv(requested_size, pvs)
+        elif self.size > requested_size + self.vg.vg_extent_size:  # more than an extent too large
+            self.shrink_cache_lv(force, requested_size, pvs)
+
+    def convert_to_cache_pool(self, force, mode):
+        lvol = self.convert_to_normal()
+        cachePoolLvol = lvol.convert_to_cache_pool(force, mode)
+
+        return cachePoolLvol
+
+    def change_pool(self, pool):
+        lvol = self.convert_to_normal()
+        lvol.convert_to_cache(pool)
+
+        self.__init__(self.module, self.vg.name, self.name, self.unit)
+
+def validate_size(module, size):
+    if '%' in size:
+        size_parts = size.split('%', 1)
+        size_percent = int(size_parts[0])
+
+        if size_percent > 100:
+            module.fail_json(msg="Size percentage cannot be larger than 100%")
+
+        size_whole = size_parts[1]
+
+        if size_whole == 'ORIGIN':
+            module.fail_json(msg="Snapshot Volumes are not supported")
+        elif size_whole not in ['VG', 'PVS', 'FREE']:
+            module.fail_json(msg="Specify extents as a percentage of VG|PVS|FREE")
+
+    if not '%' in size:
+        if size[-1].lower() in 'bskmgtpe':
+           size = size[0:-1]
+        else:
+            module.fail_json(msg="Invalid units for size: %s" % size)
+
+        try:
+           float(size)
+           if not size[0].isdigit(): raise ValueError()
+        except ValueError:
+           module.fail_json(msg="Bad size specification of '%s'" % size)
+
+def main():
+    module = AnsibleModule(
+        argument_spec=dict(
+            vg=dict(required=True),
+            lv=dict(required=True),
+            size=dict(type='str'),
+            opts=dict(type='str'),
+            state=dict(choices=["absent", "present"], default='present'),
+            force=dict(type='bool', default='no'),
+            pvs=dict(type='str'),
+            type=dict(choices=["cache", "cache-pool", "normal"], default="normal"),
+            mode=dict(choices=["writeback", "writethrough"], default='writethrough'),
+            pool=dict(type='str')
+        ),
+        supports_check_mode=True,
+    )
+
+    vg = module.params['vg']
+    lv = module.params['lv']
+    size = module.params['size']
+    opts = module.params['opts']
+    state = module.params['state']
+    force = module.boolean(module.params['force'])
+    pvs = module.params['pvs']
+    type = module.params['type']
+    mode = module.params['mode']
+    pool = module.params['pool']
+
+    if size: validate_size(module, size)
+
+    if pvs is None:
+        pvs = ""
+    else:
+        pvs = pvs.replace(",", " ")
+
+    if opts is None:
+        opts = ""
+
+    # when no unit, megabytes by default
+    if '%' in size:
+        unit = 'm'
+    else:
+        unit = size[-1].lower()
+
+    changed = False
+    msg = ''
+
+    if type == 'cache' and not pool:
+        module.fail_json(msg="You must specify also pool when type is cache")
+
+    if state == 'present' and not size:
+        if not Lvol.exists(module, vg, lv):
+            module.fail_json(msg="No size given.")
+        else:
+            module.exit_json(changed=False, vg=vg, lv=lv, size=vg)
+
+    vg_obj = Vg(module, vg, unit)
+
+    if not Lvol.exists(module, vg, lv):
+        if state == 'present':
+            if module.check_mode:
+                changed = True
+            else:
+                requested_size = Lvol.calculate_size(vg_obj.free, vg_obj.size, 0, size)
+
+                if type != "normal":
+                    if type == 'cache':
+                        CacheLvol.create_lv(module, requested_size, unit, opts, vg, lv, pvs, pool)
+                    elif type == 'cache-pool':
+                        CachePoolLvol.create_lv(module, requested_size, unit, opts, vg, lv, pvs, mode)
+                else:
+                    Lvol.create_lv(module, requested_size, unit, opts, vg, lv, pvs)
+
+                changed = True
+                msg="Volume %s/%s created" % (vg, lv)
+    else:
+        if state == 'absent':
+            if module.check_mode:
+                module.exit_json(changed=True)
+            else:
+                if Lvol.is_cache_lv(module, vg, lv):
+                    cacheLvol = CacheLvol(module, vg, lv, unit)
+                    lvol = cacheLvol.convert_to_normal()
+
+                    changed = True
+                    msg = "Volume %s converted to normal LV to %s." % (lv, size)
+
+                Lvol.delete_lv(module, force, vg, lv)
+
+                changed = True
+                msg += "Volume %s/%s deleted." % (vg, lv)
+        else:
+            if module.check_mode:
+                changed = True
+            else:
+                if type != "normal":
+                    if type == 'cache':
+                        if not Lvol.is_cache_lv(module, vg, lv):
+                            if Lvol.is_cache_pool(module, vg, lv):
+                                cachePoolLvol = CachePoolLvol(module, vg, lv, unit)
+                                cacheLvol = cachePoolLvol.convert_to_cache(force, opts, pvs, pool)
+                            else:
+                                lvol = Lvol(module, vg, lv, unit)
+                                cacheLvol = lvol.convert_to_cache(pool)
+
+                            changed = True
+                            msg = "Volume %s converted to cache LV to %s." % (lv, size)
+                        else:
+                            cacheLvol = CacheLvol(module, vg, lv, unit)
+
+                        requested_size = cacheLvol.calculate_size(vg_obj.free, vg_obj.size, cacheLvol.size, size)
+                        lvol_size_min = cacheLvol.size - vg_obj.vg_extent_size
+                        lvol_size_max = cacheLvol.size + vg_obj.vg_extent_size
+
+                        current_pool = "%s/%s" % (cacheLvol.vg.name, cacheLvol.pool_lv)
+
+                        if pool != current_pool:
+                            cacheLvol.change_pool(pool)
+
+                            changed = True
+                            msg += "Changed pool of %s to %s." % (lv, pool)
+
+                        if not (lvol_size_min <= requested_size <= lvol_size_max):
+                            cacheLvol.resize_lv(force, requested_size, pvs)
+
+                            changed = True
+                            msg += "Volume %s resized to %s." % (lv, size)
+
+                    elif type == 'cache-pool':
+                        if not Lvol.is_cache_pool(module, vg, lv):
+                            if Lvol.is_cache_lv(module, vg, lv):
+                                cacheLvol = CacheLvol(module, vg, lv, unit)
+                                cachePoolLvol = cacheLvol.convert_to_cache_pool(force, mode)
+                            else:
+                                lvol = Lvol(module, vg, lv, unit)
+                                cachePoolLvol = lvol.convert_to_cache_pool(force, mode)
+
+                            changed = True
+                            msg = "Volume %s converted to cache pool to %s." % (lv, size)
+                        else:
+                            cachePoolLvol = CachePoolLvol(module, vg, lv, unit)
+
+                        requested_size = cachePoolLvol.calculate_size(vg_obj.free, vg_obj.size, cachePoolLvol.size, size)
+                        lvol_size_min = cachePoolLvol.size - vg_obj.vg_extent_size
+                        lvol_size_max = cachePoolLvol.size + vg_obj.vg_extent_size
+
+                        if mode != cachePoolLvol.cachemode:
+                            cachePoolLvol.change_mode(force, opts, pvs, mode)
+
+                            changed = True
+                            msg += "Changed pool mode of %s to %s." % (lv, mode)
+
+                        if not (lvol_size_min <= requested_size <= lvol_size_max):
+                            cachePoolLvol.resize_lv(force, requested_size, pvs)
+
+                            changed = True
+                            msg += "Volume %s resized to %s." % (lv, size)
+                else:
+                    if Lvol.is_cache_lv(module, vg, lv):
+                            cacheLvol = CacheLvol(module, vg, lv, unit)
+                            lvol = cacheLvol.convert_to_normal()
+
+                            changed = True
+                            msg = "Volume %s converted to normal LV to %s." % (lv, size)
+                    elif Lvol.is_cache_pool(module, vg, lv):
+                            cachePoolLvol = CachePoolLvol(module, vg, lv, unit)
+                            cache_lvol_name = cachePoolLvol.get_cache_lvol_name()
+
+                            if cache_lvol_name is not None:
+                                cacheLvol = CacheLvol(module, vg, cache_lvol_name, unit)
+                                lvol = cacheLvol.convert_to_normal()
+                            else:
+                                lvol = cachePoolLvol.convert_to_normal(force, opts, pvs)
+
+                            changed = True
+                            msg += "Volume %s converted to normal LV to %s." % (lv, size)
+                    else:
+                        lvol = Lvol(module, vg, lv, unit)
+
+                    requested_size = lvol.calculate_size(vg_obj.free, vg_obj.size, lvol.size, size)
+                    lvol_size_min = lvol.size - vg_obj.vg_extent_size
+                    lvol_size_max = lvol.size + vg_obj.vg_extent_size
+
+                    if not (lvol_size_min <= requested_size <= lvol_size_max):
+                        lvol.resize_lv(force, requested_size, pvs)
+
+                        changed = True
+                        msg += "Volume %s resized to %s." % (lv, size)
+
+    module.exit_json(changed=changed, msg=msg)
+
+if __name__ == '__main__':
+    main()