Merge pull request ceph#46876 from neesingh-rh/feature_55821

mgr/volumes: add interface to check the presence of subvolumegroups/subvolumes

Reviewed-by: Venky Shankar <[email protected]>
Reviewed-by: Kotresh HR <[email protected]>
Reviewed-by: Nikhilkumar Shelke <[email protected]>
Reviewed-by: Anthony D'Atri <[email protected]>

doc/cephfs/fs-volumes.rst

@@ -152,6 +152,16 @@ The output format is json and contains fields as follows.
 * created_at: time of creation of subvolume group in the format "YYYY-MM-DD HH:MM:SS"
 * data_pool: data pool the subvolume group belongs to
 
+Check the presence of any subvolume group using::
+
+    $ ceph fs subvolumegroup exist <vol_name>
+
+The strings returned by the 'exist' command:
+    * "subvolumegroup exists": if any subvolumegroup is present
+    * "no subvolumegroup exists": if no subvolumegroup is present
+
+.. note:: It checks for the presence of custom groups and not the default one. To validate the emptiness of the volume, subvolumegroup existence check alone is not sufficient. The subvolume existence also needs to be checked as there might be subvolumes in the default group.
+
 Resize a subvolume group using::
 
     $ ceph fs subvolumegroup resize <vol_name> <group_name> <new_size> [--no_shrink]
@@ -292,6 +302,14 @@ List subvolumes using::
 
 .. note:: subvolumes that are removed but have snapshots retained, are also listed.
 
+Check the presence of any subvolume using::
+
+    $ ceph fs subvolume exist <vol_name> [--group_name <subvol_group_name>]
+
+The strings returned by the 'exist' command:
+    * "subvolume exists": if any subvolume of given group_name is present
+    * "no subvolume exists": if no subvolume of given group_name is present
+
 Set custom metadata on the subvolume as a key-value pair using::
 
     $ ceph fs subvolume metadata set <vol_name> <subvol_name> <key_name> <value> [--group_name <subvol_group_name>]

qa/tasks/cephfs/test_volumes.py

@@ -1650,6 +1650,66 @@ def test_subvolume_group_rm_force(self):
         except CommandFailedError:
             raise RuntimeError("expected the 'fs subvolumegroup rm --force' command to succeed")
 
+    def test_subvolume_group_exists_with_subvolumegroup_and_no_subvolume(self):
+        """Test the presence of any subvolumegroup when only subvolumegroup is present"""
+
+        group = self._generate_random_group_name()
+        # create subvolumegroup
+        self._fs_cmd("subvolumegroup", "create", self.volname, group)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "subvolumegroup exists")
+        # delete subvolumegroup
+        self._fs_cmd("subvolumegroup", "rm", self.volname, group)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolumegroup exists")
+
+    def test_subvolume_group_exists_with_no_subvolumegroup_and_subvolume(self):
+        """Test the presence of any subvolumegroup when no subvolumegroup is present"""
+
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolumegroup exists")
+
+    def test_subvolume_group_exists_with_subvolumegroup_and_subvolume(self):
+        """Test the presence of any subvolume when subvolumegroup
+            and subvolume both are present"""
+
+        group = self._generate_random_group_name()
+        subvolume = self._generate_random_subvolume_name(2)
+        # create subvolumegroup
+        self._fs_cmd("subvolumegroup", "create", self.volname, group)
+        # create subvolume in group
+        self._fs_cmd("subvolume", "create", self.volname, subvolume[0], "--group_name", group)
+        # create subvolume
+        self._fs_cmd("subvolume", "create", self.volname, subvolume[1])
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "subvolumegroup exists")
+        # delete subvolume in group
+        self._fs_cmd("subvolume", "rm", self.volname, subvolume[0], "--group_name", group)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "subvolumegroup exists")
+        # delete subvolume
+        self._fs_cmd("subvolume", "rm", self.volname, subvolume[1])
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "subvolumegroup exists")
+        # delete subvolumegroup
+        self._fs_cmd("subvolumegroup", "rm", self.volname, group)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolumegroup exists")
+
+    def test_subvolume_group_exists_without_subvolumegroup_and_with_subvolume(self):
+        """Test the presence of any subvolume when subvolume is present
+            but no subvolumegroup is present"""
+
+        subvolume = self._generate_random_subvolume_name()
+        # create subvolume
+        self._fs_cmd("subvolume", "create", self.volname, subvolume)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolumegroup exists")
+        # delete subvolume
+        self._fs_cmd("subvolume", "rm", self.volname, subvolume)
+        ret = self._fs_cmd("subvolumegroup", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolumegroup exists")
+
 
 class TestSubvolumes(TestVolumesHelper):
     """Tests for FS subvolume operations, except snapshot and snapshot clone."""
@@ -3271,6 +3331,57 @@ def test_subvolume_rm_force(self):
         except CommandFailedError:
             self.fail("expected the 'fs subvolume rm --force' command to succeed")
 
+    def test_subvolume_exists_with_subvolumegroup_and_subvolume(self):
+        """Test the presence of any subvolume by specifying the name of subvolumegroup"""
+
+        group = self._generate_random_group_name()
+        subvolume1 = self._generate_random_subvolume_name()
+        # create subvolumegroup
+        self._fs_cmd("subvolumegroup", "create", self.volname, group)
+        # create subvolume in group
+        self._fs_cmd("subvolume", "create", self.volname, subvolume1, "--group_name", group)
+        ret = self._fs_cmd("subvolume", "exist", self.volname, "--group_name", group)
+        self.assertEqual(ret.strip('\n'), "subvolume exists")
+        # delete subvolume in group
+        self._fs_cmd("subvolume", "rm", self.volname, subvolume1, "--group_name", group)
+        ret = self._fs_cmd("subvolume", "exist", self.volname, "--group_name", group)
+        self.assertEqual(ret.strip('\n'), "no subvolume exists")
+        # delete subvolumegroup
+        self._fs_cmd("subvolumegroup", "rm", self.volname, group)
+
+    def test_subvolume_exists_with_subvolumegroup_and_no_subvolume(self):
+        """Test the presence of any subvolume specifying the name
+            of subvolumegroup and no subvolumes"""
+
+        group = self._generate_random_group_name()
+        # create subvolumegroup
+        self._fs_cmd("subvolumegroup", "create", self.volname, group)
+        ret = self._fs_cmd("subvolume", "exist", self.volname, "--group_name", group)
+        self.assertEqual(ret.strip('\n'), "no subvolume exists")
+        # delete subvolumegroup
+        self._fs_cmd("subvolumegroup", "rm", self.volname, group)
+
+    def test_subvolume_exists_without_subvolumegroup_and_with_subvolume(self):
+        """Test the presence of any subvolume without specifying the name
+            of subvolumegroup"""
+
+        subvolume1 = self._generate_random_subvolume_name()
+        # create subvolume
+        self._fs_cmd("subvolume", "create", self.volname, subvolume1)
+        ret = self._fs_cmd("subvolume", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "subvolume exists")
+        # delete subvolume
+        self._fs_cmd("subvolume", "rm", self.volname, subvolume1)
+        ret = self._fs_cmd("subvolume", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolume exists")
+
+    def test_subvolume_exists_without_subvolumegroup_and_without_subvolume(self):
+        """Test the presence of any subvolume without any subvolumegroup
+            and without any subvolume"""
+
+        ret = self._fs_cmd("subvolume", "exist", self.volname)
+        self.assertEqual(ret.strip('\n'), "no subvolume exists")
+
     def test_subvolume_shrink(self):
         """
         That a subvolume can be shrinked in size and its quota matches the expected size.

src/pybind/mgr/volumes/fs/fs_util.py

@@ -88,6 +88,28 @@ def listdir(fs, dirpath, filter_entries=None):
         raise VolumeException(-e.args[0], e.args[1])
     return dirs
 
+
+def has_subdir(fs, dirpath, filter_entries=None):
+    """
+    Check the presence of directory (only dirs) for a given path
+    """
+    res = False
+    if filter_entries is None:
+        filter_entries = [b".", b".."]
+    else:
+        filter_entries.extend([b".", b".."])
+    try:
+        with fs.opendir(dirpath) as dir_handle:
+            d = fs.readdir(dir_handle)
+            while d:
+                if (d.d_name not in filter_entries) and d.is_dir():
+                    res = True
+                    break
+                d = fs.readdir(dir_handle)
+    except cephfs.Error as e:
+        raise VolumeException(-e.args[0], e.args[1])
+    return res
+
 def is_inherited_snap(snapname):
     """
     Returns True if the snapname is inherited else False

src/pybind/mgr/volumes/fs/operations/group.py

@@ -8,7 +8,7 @@
 from .snapshot_util import mksnap, rmsnap
 from .pin_util import pin
 from .template import GroupTemplate
-from ..fs_util import listdir, listsnaps, get_ancestor_xattr, create_base_dir
+from ..fs_util import listdir, listsnaps, get_ancestor_xattr, create_base_dir, has_subdir
 from ..exception import VolumeException
 
 log = logging.getLogger(__name__)
@@ -64,6 +64,15 @@ def list_subvolumes(self):
                 return []
             raise
 
+    def has_subvolumes(self):
+        try:
+            return has_subdir(self.fs, self.path)
+        except VolumeException as ve:
+            # listing a default group when it's not yet created
+            if ve.errno == -errno.ENOENT and self.is_default_group():
+                return False
+            raise
+
     def pin(self, pin_type, pin_setting):
         return pin(self.fs, self.path, pin_type, pin_setting)
 

src/pybind/mgr/volumes/fs/vol_spec.py

@@ -1,3 +1,9 @@
+from .operations.index import Index
+from .operations.group import Group
+from .operations.trash import Trash
+from .operations.versions.subvolume_base import SubvolumeBase
+
+
 class VolSpec(object):
     """
     specification of a "volume" -- base directory and various prefixes.
@@ -9,6 +15,8 @@ class VolSpec(object):
     DEFAULT_NS_PREFIX = "fsvolumens_"
     # default mode for subvol prefix and group
     DEFAULT_MODE = 0o755
+    # internal directories
+    INTERNAL_DIRS = [Group.NO_GROUP_NAME, Index.GROUP_NAME, Trash.GROUP_NAME, SubvolumeBase.LEGACY_CONF_DIR]
 
     def __init__(self, snapshot_prefix, subvolume_prefix=None, pool_ns_prefix=None):
         self.snapshot_prefix = snapshot_prefix

src/pybind/mgr/volumes/fs/volume.py

@@ -1,13 +1,14 @@
 import json
 import errno
 import logging
+import os
 from typing import TYPE_CHECKING
 
 import cephfs
 
 from mgr_util import CephfsClient
 
-from .fs_util import listdir
+from .fs_util import listdir, has_subdir
 
 from .operations.volume import create_volume, \
     delete_volume, rename_volume, list_volumes, open_volume, get_pool_names
@@ -466,6 +467,28 @@ def list_subvolumes(self, **kwargs):
             ret = self.volume_exception_to_retval(ve)
         return ret
 
+    def subvolume_exists(self, **kwargs):
+        volname = kwargs['vol_name']
+        groupname = kwargs['group_name']
+        ret = 0, "", ""
+        volume_exists = False
+
+        try:
+            with open_volume(self, volname) as fs_handle:
+                volume_exists = True
+                with open_group(fs_handle, self.volspec, groupname) as group:
+                    res = group.has_subvolumes()
+                    if res:
+                        ret = 0, "subvolume exists", ""
+                    else:
+                        ret = 0, "no subvolume exists", ""
+        except VolumeException as ve:
+            if volume_exists and ve.errno == -errno.ENOENT:
+                ret = 0, "no subvolume exists", ""
+            else:
+                ret = self.volume_exception_to_retval(ve)
+        return ret
+
     ### subvolume snapshot
 
     def create_subvolume_snapshot(self, **kwargs):
@@ -864,6 +887,27 @@ def pin_subvolume_group(self, **kwargs):
             ret = self.volume_exception_to_retval(ve)
         return ret
 
+    def subvolume_group_exists(self, **kwargs):
+        volname = kwargs['vol_name']
+        ret = 0, "", ""
+        volume_exists = False
+
+        try:
+            with open_volume(self, volname) as fs_handle:
+                volume_exists = True
+                res = has_subdir(fs_handle, self.volspec.base_dir, filter_entries=[
+                                 dir.encode('utf-8') for dir in self.volspec.INTERNAL_DIRS])
+                if res:
+                    ret = 0, "subvolumegroup exists", ""
+                else:
+                    ret = 0, "no subvolumegroup exists", ""
+        except VolumeException as ve:
+            if volume_exists and ve.errno == -errno.ENOENT:
+                ret = 0, "no subvolumegroup exists", ""
+            else:
+                ret = self.volume_exception_to_retval(ve)
+        return ret
+
     ### group snapshot
 
     def create_subvolume_group_snapshot(self, **kwargs):

src/pybind/mgr/volumes/module.py

@@ -111,6 +111,12 @@ class Module(orchestrator.OrchestratorClientMixin, MgrModule):
             'desc': "Resize a CephFS subvolume group",
             'perm': 'rw'
         },
+        {
+            'cmd': 'fs subvolumegroup exist '
+                   'name=vol_name,type=CephString ',
+            'desc': "Check a volume for the existence of subvolumegroup",
+            'perm': 'r'
+        },
         {
             'cmd': 'fs subvolume ls '
                    'name=vol_name,type=CephString '
@@ -210,6 +216,14 @@ class Module(orchestrator.OrchestratorClientMixin, MgrModule):
                     "and optionally, in a specific subvolume group",
             'perm': 'r'
         },
+        {
+            'cmd': 'fs subvolume exist '
+                   'name=vol_name,type=CephString '
+                   'name=group_name,type=CephString,req=false ',
+            'desc': "Check a volume for the existence of a subvolume, "
+                    "optionally in a specified subvolume group",
+            'perm': 'r'
+        },
         {
             'cmd': 'fs subvolume metadata set '
                    'name=vol_name,type=CephString '
@@ -567,6 +581,10 @@ def _cmd_fs_subvolumegroup_resize(self, inbuf, cmd):
     def _cmd_fs_subvolumegroup_ls(self, inbuf, cmd):
         return self.vc.list_subvolume_groups(vol_name=cmd['vol_name'])
 
+    @mgr_cmd_wrap
+    def _cmd_fs_subvolumegroup_exist(self, inbuf, cmd):
+        return self.vc.subvolume_group_exists(vol_name=cmd['vol_name'])
+
     @mgr_cmd_wrap
     def _cmd_fs_subvolume_create(self, inbuf, cmd):
         """
@@ -657,6 +675,11 @@ def _cmd_fs_subvolume_info(self, inbuf, cmd):
                                       sub_name=cmd['sub_name'],
                                       group_name=cmd.get('group_name', None))
 
+    @mgr_cmd_wrap
+    def _cmd_fs_subvolume_exist(self, inbuf, cmd):
+        return self.vc.subvolume_exists(vol_name=cmd['vol_name'],
+                                        group_name=cmd.get('group_name', None))
+
     @mgr_cmd_wrap
     def _cmd_fs_subvolume_metadata_set(self, inbuf, cmd):
         return self.vc.set_user_metadata(vol_name=cmd['vol_name'],