rm_dentries.py

"""
Copyright 2017 Red Hat, Inc
Author: John Spray <john.spray@redhat.com>
License: LGPLv2
Middle name: Danger
"""

import rados
import cephfs
import sys
import json
import logging
import os


log = logging.getLogger("schwack_dentries")
log.addHandler(logging.StreamHandler())
log.setLevel(logging.DEBUG)


#CEPH_CONF = "/etc/ceph/ceph.conf"
CEPH_CONF = "./ceph.conf"
SEARCH_PATH = "/teuthology-archive"
METADATA_POOL = "metadata"

damage_json_path = sys.argv[1]

damage_json = json.load(open(damage_json_path, "r"))

dirs_damaged = [d['ino'] for d in damage_json if d['damage_type'] == "dir_frag" and d['frag'] == "*"]

def find_dentries(dir_damaged_inos):
    """
    Given a list of inode numbers of directories whose * dirfrag could not be found,
    find dentries linking to those directories, and remove these dentries from the
    OMAP of the parent.
    """

    commands = []
    commands.append("ceph daemon mds.mira049 flush journal")

    r = rados.Rados(conffile=CEPH_CONF)
    r.connect()

    metadata_io = r.open_ioctx(METADATA_POOL)
    assert metadata_io

    c = cephfs.LibCephFS(rados_inst=r)
    c.mount()

    s = c.stat(SEARCH_PATH)
    parent_ino = s.st_ino

    d = c.opendir(SEARCH_PATH)
    dentry = c.readdir(d)
    while dentry:
        if dentry.d_ino in dir_damaged_inos:
            log.debug("Found ino 0x%x at %x/%s" % (dentry.d_ino, parent_ino, dentry.d_name))
            path = os.path.join(SEARCH_PATH, dentry.d_name)
            parent_frag_obj = "%x.00000000" % parent_ino
            omap_key = "%s_head" % dentry.d_name

            rop = metadata_io.create_read_op()
            with rados.ReadOpCtx(metadata_io) as rop:
                it, prval = metadata_io.get_omap_vals_by_keys(rop, (omap_key,))
                assert prval == 0
                try:
                    metadata_io.operate_read_op(rop, parent_frag_obj)
                    old_val = list(it)[0][1]
                except rados.ObjectNotFound, IndexError:
                    log.warn("OMAP key '%s' not found in dirfrag object %s for inode 0x%x linked at %s" % (omap_key, parent_frag_obj, dentry.d_ino, path))
                else:
                    open("%s_%s.bin" % (parent_frag_obj, omap_key), "w").write(old_val)
                    commands.append("rados -p {0} rmomapkey {1} {2}".format(METADATA_POOL, parent_frag_obj, omap_key))
            #old_val = list(it)[0]
            #print old_val
            
        dentry = c.readdir(d)

    c.closedir(d)

    c.unmount()

    if len(commands):
        commands.append("systemctl restart ceph-mds@mira049")
        commands.append("ceph daemon mds.mira049 scrub_path %s repair" % SEARCH_PATH)

    return commands


commands = find_dentries(dirs_damaged)
print "#!/bin/bash"
print "set -e"
print "\n".join(commands)