Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/pybind/mgr/volumes/fs/purge_queue.py b/src/pybind/mgr/volumes/fs/purge_queue.py
new file mode 100644
index 000000000..abace19d0
--- /dev/null
+++ b/src/pybind/mgr/volumes/fs/purge_queue.py
@@ -0,0 +1,113 @@
+import errno
+import logging
+import os
+import stat
+
+import cephfs
+
+from .async_job import AsyncJobs
+from .exception import VolumeException
+from .operations.resolver import resolve_trash
+from .operations.template import SubvolumeOpType
+from .operations.group import open_group
+from .operations.subvolume import open_subvol
+from .operations.volume import open_volume, open_volume_lockless
+from .operations.trash import open_trashcan
+
+log = logging.getLogger(__name__)
+
+
+# helper for fetching a trash entry for a given volume
+def get_trash_entry_for_volume(fs_client, volspec, volname, running_jobs):
+    log.debug("fetching trash entry for volume '{0}'".format(volname))
+
+    try:
+        with open_volume_lockless(fs_client, volname) as fs_handle:
+            try:
+                with open_trashcan(fs_handle, volspec) as trashcan:
+                    path = trashcan.get_trash_entry(running_jobs)
+                    return 0, path
+            except VolumeException as ve:
+                if ve.errno == -errno.ENOENT:
+                    return 0, None
+                raise ve
+    except VolumeException as ve:
+        log.error("error fetching trash entry for volume '{0}' ({1})".format(volname, ve))
+        return ve.errno, None
+
+
+def subvolume_purge(fs_client, volspec, volname, trashcan, subvolume_trash_entry, should_cancel):
+    groupname, subvolname = resolve_trash(volspec, subvolume_trash_entry.decode('utf-8'))
+    log.debug("subvolume resolved to {0}/{1}".format(groupname, subvolname))
+
+    try:
+        with open_volume(fs_client, volname) as fs_handle:
+            with open_group(fs_handle, volspec, groupname) as group:
+                with open_subvol(fs_client.mgr, fs_handle, volspec, group, subvolname, SubvolumeOpType.REMOVE) as subvolume:
+                    log.debug("subvolume.path={0}, purgeable={1}".format(subvolume.path, subvolume.purgeable))
+                    if not subvolume.purgeable:
+                        return
+                    # this is fine under the global lock -- there are just a handful
+                    # of entries in the subvolume to purge. moreover, the purge needs
+                    # to be guarded since a create request might sneak in.
+                    trashcan.purge(subvolume.base_path, should_cancel)
+    except VolumeException as ve:
+        if not ve.errno == -errno.ENOENT:
+            raise
+
+
+# helper for starting a purge operation on a trash entry
+def purge_trash_entry_for_volume(fs_client, volspec, volname, purge_entry, should_cancel):
+    log.debug("purging trash entry '{0}' for volume '{1}'".format(purge_entry, volname))
+
+    ret = 0
+    try:
+        with open_volume_lockless(fs_client, volname) as fs_handle:
+            with open_trashcan(fs_handle, volspec) as trashcan:
+                try:
+                    pth = os.path.join(trashcan.path, purge_entry)
+                    stx = fs_handle.statx(pth, cephfs.CEPH_STATX_MODE | cephfs.CEPH_STATX_SIZE,
+                                          cephfs.AT_SYMLINK_NOFOLLOW)
+                    if stat.S_ISLNK(stx['mode']):
+                        tgt = fs_handle.readlink(pth, 4096)
+                        tgt = tgt[:stx['size']]
+                        log.debug("purging entry pointing to subvolume trash: {0}".format(tgt))
+                        delink = True
+                        try:
+                            trashcan.purge(tgt, should_cancel)
+                        except VolumeException as ve:
+                            if not ve.errno == -errno.ENOENT:
+                                delink = False
+                                return ve.errno
+                        finally:
+                            if delink:
+                                subvolume_purge(fs_client, volspec, volname, trashcan, tgt, should_cancel)
+                                log.debug("purging trash link: {0}".format(purge_entry))
+                                trashcan.delink(purge_entry)
+                    else:
+                        log.debug("purging entry pointing to trash: {0}".format(pth))
+                        trashcan.purge(pth, should_cancel)
+                except cephfs.Error as e:
+                    log.warn("failed to remove trash entry: {0}".format(e))
+    except VolumeException as ve:
+        ret = ve.errno
+    return ret
+
+
+class ThreadPoolPurgeQueueMixin(AsyncJobs):
+    """
+    Purge queue mixin class maintaining a pool of threads for purging trash entries.
+    Subvolumes are chosen from volumes in a round robin fashion. If some of the purge
+    entries (belonging to a set of volumes) have huge directory tree's (such as, lots
+    of small files in a directory w/ deep directory trees), this model may lead to
+    _all_ threads purging entries for one volume (starving other volumes).
+    """
+    def __init__(self, volume_client, tp_size):
+        self.vc = volume_client
+        super(ThreadPoolPurgeQueueMixin, self).__init__(volume_client, "purgejob", tp_size)
+
+    def get_next_job(self, volname, running_jobs):
+        return get_trash_entry_for_volume(self.fs_client, self.vc.volspec, volname, running_jobs)
+
+    def execute_job(self, volname, job, should_cancel):
+        purge_trash_entry_for_volume(self.fs_client, self.vc.volspec, volname, job, should_cancel)