mgr/volumes: implement subvolume group based on group template

Signed-off-by: Venky Shankar <vshankar@redhat.com>
(cherry picked from commit 3eccd618ecce13052e31d07437ee2d09ae98e5c4)

diff --git a/src/pybind/mgr/volumes/fs/operations/group.py b/src/pybind/mgr/volumes/fs/operations/group.py
new file mode 100644 (file)
index 0000000..a75e9d1
--- /dev/null
+++ b/src/pybind/mgr/volumes/fs/operations/group.py
@@ -0,0 +1,174 @@
+import os
+import errno
+import logging
+from contextlib import contextmanager
+
+import cephfs
+
+from .snapshot_util import mksnap, rmsnap
+from .template import GroupTemplate
+from ..fs_util import listdir, get_ancestor_xattr
+from ..exception import VolumeException
+
+log = logging.getLogger(__name__)
+
+class Group(GroupTemplate):
+    # Reserved subvolume group name which we use in paths for subvolumes
+    # that are not assigned to a group (i.e. created with group=None)
+    NO_GROUP_NAME = "_nogroup"
+
+    def __init__(self, fs, vol_spec, groupname):
+        assert groupname != Group.NO_GROUP_NAME
+        self.fs = fs
+        self.user_id = None
+        self.group_id = None
+        self.vol_spec = vol_spec
+        self.groupname = groupname if groupname else Group.NO_GROUP_NAME
+
+    @property
+    def path(self):
+        return os.path.join(self.vol_spec.base_dir.encode('utf-8'), self.groupname.encode('utf-8'))
+
+    @property
+    def uid(self):
+        return self.user_id
+
+    @property
+    def gid(self):
+        return self.group_id
+
+    @uid.setter
+    def uid(self, val):
+        self.user_id = val
+
+    @gid.setter
+    def gid(self, val):
+        self.group_id = val
+
+    def is_default_group(self):
+        return self.groupname == Group.NO_GROUP_NAME
+
+    def list_subvolumes(self):
+        try:
+            return listdir(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 []
+            raise
+
+    def create_snapshot(self, snapname):
+        snappath = os.path.join(self.path,
+                                self.vol_spec.snapshot_dir_prefix.encode('utf-8'),
+                                snapname.encode('utf-8'))
+        mksnap(self.fs, snappath)
+
+    def remove_snapshot(self, snapname):
+        snappath = os.path.join(self.path,
+                                self.vol_spec.snapshot_dir_prefix.encode('utf-8'),
+                                snapname.encode('utf-8'))
+        rmsnap(self.fs, snappath)
+
+    def list_snapshots(self):
+        try:
+            dirpath = os.path.join(self.path,
+                                   self.vol_spec.snapshot_dir_prefix.encode('utf-8'))
+            return listdir(self.fs, dirpath)
+        except VolumeException as ve:
+            if ve.errno == -errno.ENOENT:
+                return []
+            raise
+
+def create_group(fs, vol_spec, groupname, pool, mode, uid, gid):
+    """
+    create a subvolume group.
+
+    :param fs: ceph filesystem handle
+    :param vol_spec: volume specification
+    :param groupname: subvolume group name
+    :param pool: the RADOS pool where the data objects of the subvolumes will be stored
+    :param mode: the user permissions
+    :param uid: the user identifier
+    :param gid: the group identifier
+    :return: None
+    """
+    group = Group(fs, vol_spec, groupname)
+    path = group.path
+    fs.mkdirs(path, mode)
+    try:
+        if not pool:
+            pool = get_ancestor_xattr(fs, path, "ceph.dir.layout.pool")
+        try:
+            fs.setxattr(path, 'ceph.dir.layout.pool', pool.encode('utf-8'), 0)
+        except cephfs.InvalidValue:
+            raise VolumeException(-errno.EINVAL,
+                                  "Invalid pool layout '{0}'. It must be a valid data pool".format(pool))
+        if uid is None:
+            uid = 0
+        else:
+            try:
+                uid = int(uid)
+                if uid < 0:
+                    raise ValueError
+            except ValueError:
+                raise VolumeException(-errno.EINVAL, "invalid UID")
+        if gid is None:
+            gid = 0
+        else:
+            try:
+                gid = int(gid)
+                if gid < 0:
+                    raise ValueError
+            except ValueError:
+                raise VolumeException(-errno.EINVAL, "invalid GID")
+        fs.chown(path, uid, gid)
+    except (cephfs.Error, VolumeException) as e:
+        try:
+            # cleanup group path on best effort basis
+            log.debug("cleaning up subvolume group path: {0}".format(path))
+            fs.rmdir(path)
+        except cephfs.Error as ce:
+            log.debug("failed to clean up subvolume group {0} with path: {0} ({1})".format(groupname, path, ce))
+        if isinstance(e, cephfs.Error):
+            e = VolumeException(-e.args[0], e.args[1])
+        raise e
+
+def remove_group(fs, vol_spec, groupname):
+    """
+    remove a subvolume group.
+
+    :param fs: ceph filesystem handle
+    :param vol_spec: volume specification
+    :param groupname: subvolume group name
+    :return: None
+    """
+    group = Group(fs, vol_spec, groupname)
+    try:
+        fs.rmdir(group.path)
+    except cephfs.Error as e:
+        if e.args[0] == errno.ENOENT:
+            raise VolumeException(-errno.ENOENT, "subvolume group '{0}' does not exist".format(groupname))
+        raise VolumeException(-e.args[0], e.args[1])
+
+@contextmanager
+def open_group(fs, vol_spec, groupname):
+    """
+    open a subvolume group. This API is to be used as a context manager.
+
+    :param fs: ceph filesystem handle
+    :param vol_spec: volume specification
+    :param groupname: subvolume group name
+    :return: yields a group object (subclass of GroupTemplate)
+    """
+    group = Group(fs, vol_spec, groupname)
+    try:
+        st = fs.stat(group.path)
+        group.uid = int(st.st_uid)
+        group.gid = int(st.st_gid)
+    except cephfs.Error as e:
+        if e.args[0] == errno.ENOENT:
+            if not group.is_default_group():
+                raise VolumeException(-errno.ENOENT, "subvolume group '{0}' does not exist".format(groupname))
+        else:
+            raise VolumeException(-e.args[0], e.args[1])
+    yield group