ceph/src/pybind/mgr/volumes/fs/async_cloner.py

   1 import os
   2 import stat
   3 import time
   4 import errno
   5 import logging
   6 from contextlib import contextmanager
   7 from typing import Dict, Union
   8
   9 import cephfs
  10 from mgr_util import lock_timeout_log
  11
  12 from .async_job import AsyncJobs
  13 from .exception import IndexException, MetadataMgrException, OpSmException, VolumeException
  14 from .fs_util import copy_file
  15 from .operations.versions.op_sm import SubvolumeOpSm
  16 from .operations.versions.subvolume_attrs import SubvolumeTypes, SubvolumeStates, SubvolumeActions
  17 from .operations.resolver import resolve
  18 from .operations.volume import open_volume, open_volume_lockless
  19 from .operations.group import open_group
  20 from .operations.subvolume import open_subvol
  21 from .operations.clone_index import open_clone_index
  22 from .operations.template import SubvolumeOpType
  23
  24 log = logging.getLogger(__name__)
  25
  26 # helper for fetching a clone entry for a given volume
  27 def get_next_clone_entry(fs_client, volspec, volname, running_jobs):
  28     log.debug("fetching clone entry for volume '{0}'".format(volname))
  29
  30     try:
  31         with open_volume_lockless(fs_client, volname) as fs_handle:
  32             try:
  33                 with open_clone_index(fs_handle, volspec) as clone_index:
  34                     job = clone_index.get_oldest_clone_entry(running_jobs)
  35                     return 0, job
  36             except IndexException as ve:
  37                 if ve.errno == -errno.ENOENT:
  38                     return 0, None
  39                 raise ve
  40     except VolumeException as ve:
  41         log.error("error fetching clone entry for volume '{0}' ({1})".format(volname, ve))
  42         return ve.errno, None
  43
  44 @contextmanager
  45 def open_at_volume(fs_client, volspec, volname, groupname, subvolname, op_type):
  46     with open_volume(fs_client, volname) as fs_handle:
  47         with open_group(fs_handle, volspec, groupname) as group:
  48             with open_subvol(fs_client.mgr, fs_handle, volspec, group, subvolname, op_type) as subvolume:
  49                 yield subvolume
  50
  51 @contextmanager
  52 def open_at_group(fs_client, fs_handle, volspec, groupname, subvolname, op_type):
  53     with open_group(fs_handle, volspec, groupname) as group:
  54         with open_subvol(fs_client.mgr, fs_handle, volspec, group, subvolname, op_type) as subvolume:
  55             yield subvolume
  56
  57 @contextmanager
  58 def open_at_group_unique(fs_client, fs_handle, volspec, s_groupname, s_subvolname, c_subvolume, c_groupname, c_subvolname, op_type):
  59     # if a snapshot of a retained subvolume is being cloned to recreate the same subvolume, return
  60     # the clone subvolume as the source subvolume
  61     if s_groupname == c_groupname and s_subvolname == c_subvolname:
  62         yield c_subvolume
  63     else:
  64         with open_at_group(fs_client, fs_handle, volspec, s_groupname, s_subvolname, op_type) as s_subvolume:
  65             yield s_subvolume
  66
  67
  68 @contextmanager
  69 def open_clone_subvolume_pair(fs_client, fs_handle, volspec, volname, groupname, subvolname):
  70     with open_at_group(fs_client, fs_handle, volspec, groupname, subvolname, SubvolumeOpType.CLONE_INTERNAL) as clone_subvolume:
  71         s_volname, s_groupname, s_subvolname, s_snapname = get_clone_source(clone_subvolume)
  72         if groupname == s_groupname and subvolname == s_subvolname:
  73             # use the same subvolume to avoid metadata overwrites
  74             yield (clone_subvolume, clone_subvolume, s_snapname)
  75         else:
  76             with open_at_group(fs_client, fs_handle, volspec, s_groupname, s_subvolname, SubvolumeOpType.CLONE_SOURCE) as source_subvolume:
  77                 yield (clone_subvolume, source_subvolume, s_snapname)
  78
  79 def get_clone_state(fs_client, volspec, volname, groupname, subvolname):
  80     with open_at_volume(fs_client, volspec, volname, groupname, subvolname, SubvolumeOpType.CLONE_INTERNAL) as subvolume:
  81         return subvolume.state
  82
  83 def set_clone_state(fs_client, volspec, volname, groupname, subvolname, state):
  84     with open_at_volume(fs_client, volspec, volname, groupname, subvolname, SubvolumeOpType.CLONE_INTERNAL) as subvolume:
  85         subvolume.state = (state, True)
  86
  87 def get_clone_source(clone_subvolume):
  88     source = clone_subvolume._get_clone_source()
  89     return (source['volume'], source.get('group', None), source['subvolume'], source['snapshot'])
  90
  91 def get_next_state_on_error(errnum):
  92     if errnum == -errno.EINTR:
  93         next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
  94                                               SubvolumeStates.STATE_INPROGRESS,
  95                                               SubvolumeActions.ACTION_CANCELLED)
  96     else:
  97         # jump to failed state, on all other errors
  98         next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
  99                                               SubvolumeStates.STATE_INPROGRESS,
 100                                               SubvolumeActions.ACTION_FAILED)
 101     return next_state
 102
 103 def handle_clone_pending(fs_client, volspec, volname, index, groupname, subvolname, should_cancel):
 104     try:
 105         if should_cancel():
 106             next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
 107                                                   SubvolumeStates.STATE_PENDING,
 108                                                   SubvolumeActions.ACTION_CANCELLED)
 109         else:
 110             next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
 111                                                   SubvolumeStates.STATE_PENDING,
 112                                                   SubvolumeActions.ACTION_SUCCESS)
 113     except OpSmException as oe:
 114         raise VolumeException(oe.errno, oe.error_str)
 115     return (next_state, False)
 116
 117 def sync_attrs(fs_handle, target_path, source_statx):
 118     try:
 119         fs_handle.lchown(target_path, source_statx["uid"], source_statx["gid"])
 120         fs_handle.lutimes(target_path, (time.mktime(source_statx["atime"].timetuple()),
 121                                         time.mktime(source_statx["mtime"].timetuple())))
 122         fs_handle.lchmod(target_path, source_statx["mode"])
 123     except cephfs.Error as e:
 124         log.warning("error synchronizing attrs for {0} ({1})".format(target_path, e))
 125         raise e
 126
 127 def bulk_copy(fs_handle, source_path, dst_path, should_cancel):
 128     """
 129     bulk copy data from source to destination -- only directories, symlinks
 130     and regular files are synced.
 131     """
 132     log.info("copying data from {0} to {1}".format(source_path, dst_path))
 133     def cptree(src_root_path, dst_root_path):
 134         log.debug("cptree: {0} -> {1}".format(src_root_path, dst_root_path))
 135         try:
 136             with fs_handle.opendir(src_root_path) as dir_handle:
 137                 d = fs_handle.readdir(dir_handle)
 138                 while d and not should_cancel():
 139                     if d.d_name not in (b".", b".."):
 140                         log.debug("d={0}".format(d))
 141                         d_full_src = os.path.join(src_root_path, d.d_name)
 142                         d_full_dst = os.path.join(dst_root_path, d.d_name)
 143                         stx = fs_handle.statx(d_full_src, cephfs.CEPH_STATX_MODE  |
 144                                                           cephfs.CEPH_STATX_UID   |
 145                                                           cephfs.CEPH_STATX_GID   |
 146                                                           cephfs.CEPH_STATX_ATIME |
 147                                                           cephfs.CEPH_STATX_MTIME |
 148                                                           cephfs.CEPH_STATX_SIZE,
 149                                                           cephfs.AT_SYMLINK_NOFOLLOW)
 150                         handled = True
 151                         mo = stx["mode"] & ~stat.S_IFMT(stx["mode"])
 152                         if stat.S_ISDIR(stx["mode"]):
 153                             log.debug("cptree: (DIR) {0}".format(d_full_src))
 154                             try:
 155                                 fs_handle.mkdir(d_full_dst, mo)
 156                             except cephfs.Error as e:
 157                                 if not e.args[0] == errno.EEXIST:
 158                                     raise
 159                             cptree(d_full_src, d_full_dst)
 160                         elif stat.S_ISLNK(stx["mode"]):
 161                             log.debug("cptree: (SYMLINK) {0}".format(d_full_src))
 162                             target = fs_handle.readlink(d_full_src, 4096)
 163                             try:
 164                                 fs_handle.symlink(target[:stx["size"]], d_full_dst)
 165                             except cephfs.Error as e:
 166                                 if not e.args[0] == errno.EEXIST:
 167                                     raise
 168                         elif stat.S_ISREG(stx["mode"]):
 169                             log.debug("cptree: (REG) {0}".format(d_full_src))
 170                             copy_file(fs_handle, d_full_src, d_full_dst, mo, cancel_check=should_cancel)
 171                         else:
 172                             handled = False
 173                             log.warning("cptree: (IGNORE) {0}".format(d_full_src))
 174                         if handled:
 175                             sync_attrs(fs_handle, d_full_dst, stx)
 176                     d = fs_handle.readdir(dir_handle)
 177                 stx_root = fs_handle.statx(src_root_path, cephfs.CEPH_STATX_ATIME |
 178                                                           cephfs.CEPH_STATX_MTIME,
 179                                                           cephfs.AT_SYMLINK_NOFOLLOW)
 180                 fs_handle.lutimes(dst_root_path, (time.mktime(stx_root["atime"].timetuple()),
 181                                                   time.mktime(stx_root["mtime"].timetuple())))
 182         except cephfs.Error as e:
 183             if not e.args[0] == errno.ENOENT:
 184                 raise VolumeException(-e.args[0], e.args[1])
 185     cptree(source_path, dst_path)
 186     if should_cancel():
 187         raise VolumeException(-errno.EINTR, "clone operation interrupted")
 188
 189 def set_quota_on_clone(fs_handle, clone_volumes_pair):
 190     attrs = {}  # type: Dict[str, Union[int, str, None]]
 191     src_path = clone_volumes_pair[1].snapshot_data_path(clone_volumes_pair[2])
 192     dst_path = clone_volumes_pair[0].path
 193     try:
 194         attrs["quota"] = int(fs_handle.getxattr(src_path,
 195                                                 'ceph.quota.max_bytes'
 196                                                 ).decode('utf-8'))
 197     except cephfs.NoData:
 198         attrs["quota"] = None
 199
 200     if attrs["quota"] is not None:
 201         clone_volumes_pair[0].set_attrs(dst_path, attrs)
 202
 203 def do_clone(fs_client, volspec, volname, groupname, subvolname, should_cancel):
 204     with open_volume_lockless(fs_client, volname) as fs_handle:
 205         with open_clone_subvolume_pair(fs_client, fs_handle, volspec, volname, groupname, subvolname) as clone_volumes:
 206             src_path = clone_volumes[1].snapshot_data_path(clone_volumes[2])
 207             dst_path = clone_volumes[0].path
 208             bulk_copy(fs_handle, src_path, dst_path, should_cancel)
 209             set_quota_on_clone(fs_handle, clone_volumes)
 210
 211 def log_clone_failure(volname, groupname, subvolname, ve):
 212     if ve.errno == -errno.EINTR:
 213         log.info("Clone cancelled: ({0}, {1}, {2})".format(volname, groupname, subvolname))
 214     elif ve.errno == -errno.EDQUOT:
 215         log.error("Clone failed: ({0}, {1}, {2}, reason -> Disk quota exceeded)".format(volname, groupname, subvolname))
 216     else:
 217         log.error("Clone failed: ({0}, {1}, {2}, reason -> {3})".format(volname, groupname, subvolname, ve))
 218
 219 def handle_clone_in_progress(fs_client, volspec, volname, index, groupname, subvolname, should_cancel):
 220     try:
 221         do_clone(fs_client, volspec, volname, groupname, subvolname, should_cancel)
 222         next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
 223                                               SubvolumeStates.STATE_INPROGRESS,
 224                                               SubvolumeActions.ACTION_SUCCESS)
 225     except VolumeException as ve:
 226         log_clone_failure(volname, groupname, subvolname, ve)
 227         next_state = get_next_state_on_error(ve.errno)
 228     except OpSmException as oe:
 229         raise VolumeException(oe.errno, oe.error_str)
 230     return (next_state, False)
 231
 232 def handle_clone_failed(fs_client, volspec, volname, index, groupname, subvolname, should_cancel):
 233     try:
 234         with open_volume(fs_client, volname) as fs_handle:
 235             # detach source but leave the clone section intact for later inspection
 236             with open_clone_subvolume_pair(fs_client, fs_handle, volspec, volname, groupname, subvolname) as clone_volumes:
 237                 clone_volumes[1].detach_snapshot(clone_volumes[2], index)
 238     except (MetadataMgrException, VolumeException) as e:
 239         log.error("failed to detach clone from snapshot: {0}".format(e))
 240     return (None, True)
 241
 242 def handle_clone_complete(fs_client, volspec, volname, index, groupname, subvolname, should_cancel):
 243     try:
 244         with open_volume(fs_client, volname) as fs_handle:
 245             with open_clone_subvolume_pair(fs_client, fs_handle, volspec, volname, groupname, subvolname) as clone_volumes:
 246                 clone_volumes[1].detach_snapshot(clone_volumes[2], index)
 247                 clone_volumes[0].remove_clone_source(flush=True)
 248     except (MetadataMgrException, VolumeException) as e:
 249         log.error("failed to detach clone from snapshot: {0}".format(e))
 250     return (None, True)
 251
 252 def start_clone_sm(fs_client, volspec, volname, index, groupname, subvolname, state_table, should_cancel, snapshot_clone_delay):
 253     finished = False
 254     current_state = None
 255     try:
 256         current_state = get_clone_state(fs_client, volspec, volname, groupname, subvolname)
 257         log.debug("cloning ({0}, {1}, {2}) -- starting state \"{3}\"".format(volname, groupname, subvolname, current_state))
 258         if current_state == SubvolumeStates.STATE_PENDING:
 259             time.sleep(snapshot_clone_delay)
 260             log.info("Delayed cloning ({0}, {1}, {2}) -- by {3} seconds".format(volname, groupname, subvolname, snapshot_clone_delay))
 261         while not finished:
 262             handler = state_table.get(current_state, None)
 263             if not handler:
 264                 raise VolumeException(-errno.EINVAL, "invalid clone state: \"{0}\"".format(current_state))
 265             (next_state, finished) = handler(fs_client, volspec, volname, index, groupname, subvolname, should_cancel)
 266             if next_state:
 267                 log.debug("({0}, {1}, {2}) transition state [\"{3}\" => \"{4}\"]".format(volname, groupname, subvolname,\
 268                                                                                          current_state, next_state))
 269                 set_clone_state(fs_client, volspec, volname, groupname, subvolname, next_state)
 270                 current_state = next_state
 271     except VolumeException as ve:
 272         log.error("clone failed for ({0}, {1}, {2}) (current_state: {3}, reason: {4})".format(volname, groupname,\
 273                                                                                              subvolname, current_state, ve))
 274
 275 def clone(fs_client, volspec, volname, index, clone_path, state_table, should_cancel, snapshot_clone_delay):
 276     log.info("cloning to subvolume path: {0}".format(clone_path))
 277     resolved = resolve(volspec, clone_path)
 278
 279     groupname  = resolved[0]
 280     subvolname = resolved[1]
 281     log.debug("resolved to [group: {0}, subvolume: {1}]".format(groupname, subvolname))
 282
 283     try:
 284         log.info("starting clone: ({0}, {1}, {2})".format(volname, groupname, subvolname))
 285         start_clone_sm(fs_client, volspec, volname, index, groupname, subvolname, state_table, should_cancel, snapshot_clone_delay)
 286         log.info("finished clone: ({0}, {1}, {2})".format(volname, groupname, subvolname))
 287     except VolumeException as ve:
 288         log.error("clone failed for ({0}, {1}, {2}), reason: {3}".format(volname, groupname, subvolname, ve))
 289
 290 class Cloner(AsyncJobs):
 291     """
 292     Asynchronous cloner: pool of threads to copy data from a snapshot to a subvolume.
 293     this relies on a simple state machine (which mimics states from SubvolumeOpSm class) as
 294     the driver. file types supported are directories, symbolic links and regular files.
 295     """
 296     def __init__(self, volume_client, tp_size, snapshot_clone_delay):
 297         self.vc = volume_client
 298         self.snapshot_clone_delay = snapshot_clone_delay
 299         self.state_table = {
 300             SubvolumeStates.STATE_PENDING      : handle_clone_pending,
 301             SubvolumeStates.STATE_INPROGRESS   : handle_clone_in_progress,
 302             SubvolumeStates.STATE_COMPLETE     : handle_clone_complete,
 303             SubvolumeStates.STATE_FAILED       : handle_clone_failed,
 304             SubvolumeStates.STATE_CANCELED     : handle_clone_failed,
 305         }
 306         super(Cloner, self).__init__(volume_client, "cloner", tp_size)
 307
 308     def reconfigure_max_concurrent_clones(self, tp_size):
 309         return super(Cloner, self).reconfigure_max_async_threads(tp_size)
 310
 311     def reconfigure_snapshot_clone_delay(self, timeout):
 312         self.snapshot_clone_delay = timeout
 313
 314     def is_clone_cancelable(self, clone_state):
 315         return not (SubvolumeOpSm.is_complete_state(clone_state) or SubvolumeOpSm.is_failed_state(clone_state))
 316
 317     def get_clone_tracking_index(self, fs_handle, clone_subvolume):
 318         with open_clone_index(fs_handle, self.vc.volspec) as index:
 319             return index.find_clone_entry_index(clone_subvolume.base_path)
 320
 321     def _cancel_pending_clone(self, fs_handle, clone_subvolume, clone_subvolname, clone_groupname, status, track_idx):
 322         clone_state = SubvolumeStates.from_value(status['state'])
 323         assert self.is_clone_cancelable(clone_state)
 324
 325         s_groupname = status['source'].get('group', None)
 326         s_subvolname = status['source']['subvolume']
 327         s_snapname = status['source']['snapshot']
 328
 329         with open_at_group_unique(self.fs_client, fs_handle, self.vc.volspec, s_groupname, s_subvolname, clone_subvolume,
 330                                   clone_groupname, clone_subvolname, SubvolumeOpType.CLONE_SOURCE) as s_subvolume:
 331             next_state = SubvolumeOpSm.transition(SubvolumeTypes.TYPE_CLONE,
 332                                                   clone_state,
 333                                                   SubvolumeActions.ACTION_CANCELLED)
 334             clone_subvolume.state = (next_state, True)
 335             s_subvolume.detach_snapshot(s_snapname, track_idx.decode('utf-8'))
 336
 337     def cancel_job(self, volname, job):
 338         """
 339         override base class `cancel_job`. interpret @job as (clone, group) tuple.
 340         """
 341         clonename = job[0]
 342         groupname = job[1]
 343         track_idx = None
 344
 345         try:
 346             with open_volume(self.fs_client, volname) as fs_handle:
 347                 with open_group(fs_handle, self.vc.volspec, groupname) as group:
 348                     with open_subvol(self.fs_client.mgr, fs_handle, self.vc.volspec, group, clonename, SubvolumeOpType.CLONE_CANCEL) as clone_subvolume:
 349                         status = clone_subvolume.status
 350                         clone_state = SubvolumeStates.from_value(status['state'])
 351                         if not self.is_clone_cancelable(clone_state):
 352                             raise VolumeException(-errno.EINVAL, "cannot cancel -- clone finished (check clone status)")
 353                         track_idx = self.get_clone_tracking_index(fs_handle, clone_subvolume)
 354                         if not track_idx:
 355                             log.warning("cannot lookup clone tracking index for {0}".format(clone_subvolume.base_path))
 356                             raise VolumeException(-errno.EINVAL, "error canceling clone")
 357                         clone_job = (track_idx, clone_subvolume.base_path)
 358                         jobs = [j[0] for j in self.jobs[volname]]
 359                         with lock_timeout_log(self.lock):
 360                             if SubvolumeOpSm.is_init_state(SubvolumeTypes.TYPE_CLONE, clone_state) and not clone_job in jobs:
 361                                 logging.debug("Cancelling pending job {0}".format(clone_job))
 362                                 # clone has not started yet -- cancel right away.
 363                                 self._cancel_pending_clone(fs_handle, clone_subvolume, clonename, groupname, status, track_idx)
 364                                 return
 365             # cancelling an on-going clone would persist "canceled" state in subvolume metadata.
 366             # to persist the new state, async cloner accesses the volume in exclusive mode.
 367             # accessing the volume in exclusive mode here would lead to deadlock.
 368             assert track_idx is not None
 369             with lock_timeout_log(self.lock):
 370                 with open_volume_lockless(self.fs_client, volname) as fs_handle:
 371                     with open_group(fs_handle, self.vc.volspec, groupname) as group:
 372                         with open_subvol(self.fs_client.mgr, fs_handle, self.vc.volspec, group, clonename, SubvolumeOpType.CLONE_CANCEL) as clone_subvolume:
 373                             if not self._cancel_job(volname, (track_idx, clone_subvolume.base_path)):
 374                                 raise VolumeException(-errno.EINVAL, "cannot cancel -- clone finished (check clone status)")
 375         except (IndexException, MetadataMgrException) as e:
 376             log.error("error cancelling clone {0}: ({1})".format(job, e))
 377             raise VolumeException(-errno.EINVAL, "error canceling clone")
 378
 379     def get_next_job(self, volname, running_jobs):
 380         return get_next_clone_entry(self.fs_client, self.vc.volspec, volname, running_jobs)
 381
 382     def execute_job(self, volname, job, should_cancel):
 383         clone(self.fs_client, self.vc.volspec, volname, job[0].decode('utf-8'), job[1].decode('utf-8'), self.state_table, should_cancel, self.snapshot_clone_delay)