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# Unix SMB/CIFS implementation. Tests for DSDB locking
# Copyright (C) Andrew Bartlett <abartlet@samba.org> 2017
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
"""Tests for samba's dsdb modules"""
from samba.tests.samdb import SamDBTestCase
from samba.samdb import SamDB
import ldb
import os
import samba
import gc
import time
class DsdbLockTestCase(SamDBTestCase):
def test_db_lock1(self):
basedn = self.samdb.get_default_basedn()
(r1, w1) = os.pipe()
pid = os.fork()
if pid == 0:
# In the child, close the main DB, re-open just one DB
del(self.samdb)
gc.collect()
self.samdb = SamDB(session_info=self.session,
lp=self.lp)
self.samdb.transaction_start()
dn = "cn=test_db_lock_user,cn=users," + str(basedn)
self.samdb.add({
"dn": dn,
"objectclass": "user",
})
self.samdb.delete(dn)
# Obtain a write lock
self.samdb.transaction_prepare_commit()
os.write(w1, b"prepared")
time.sleep(2)
# Drop the write lock
self.samdb.transaction_cancel()
os._exit(0)
self.assertEqual(os.read(r1, 8), b"prepared")
start = time.time()
# We need to hold this iterator open to hold the all-record lock.
res = self.samdb.search_iterator()
# This should take at least 2 seconds because the transaction
# has a write lock on one backend db open
# Release the locks
for l in res:
pass
end = time.time()
self.assertGreater(end - start, 1.9)
(got_pid, status) = os.waitpid(pid, 0)
self.assertEqual(got_pid, pid)
self.assertTrue(os.WIFEXITED(status))
self.assertEqual(os.WEXITSTATUS(status), 0)
def test_db_lock2(self):
basedn = self.samdb.get_default_basedn()
(r1, w1) = os.pipe()
(r2, w2) = os.pipe()
pid = os.fork()
if pid == 0:
# In the child, close the main DB, re-open
del(self.samdb)
gc.collect()
self.samdb = SamDB(session_info=self.session,
lp=self.lp)
# We need to hold this iterator open to hold the all-record lock.
res = self.samdb.search_iterator()
os.write(w2, b"start")
if (os.read(r1, 7) != b"started"):
os._exit(1)
os.write(w2, b"add")
if (os.read(r1, 5) != b"added"):
os._exit(2)
# Wait 2 seconds to block prepare_commit() in the child.
os.write(w2, b"prepare")
time.sleep(2)
# Release the locks
for l in res:
pass
if (os.read(r1, 8) != b"prepared"):
os._exit(3)
os._exit(0)
# We can start the transaction during the search
# because both just grab the all-record read lock.
self.assertEqual(os.read(r2, 5), b"start")
self.samdb.transaction_start()
os.write(w1, b"started")
self.assertEqual(os.read(r2, 3), b"add")
dn = "cn=test_db_lock_user,cn=users," + str(basedn)
self.samdb.add({
"dn": dn,
"objectclass": "user",
})
self.samdb.delete(dn)
os.write(w1, b"added")
# Obtain a write lock, this will block until
# the parent releases the read lock.
self.assertEqual(os.read(r2, 7), b"prepare")
start = time.time()
self.samdb.transaction_prepare_commit()
end = time.time()
try:
self.assertGreater(end - start, 1.9)
except:
raise
finally:
os.write(w1, b"prepared")
# Drop the write lock
self.samdb.transaction_cancel()
(got_pid, status) = os.waitpid(pid, 0)
self.assertEqual(got_pid, pid)
self.assertTrue(os.WIFEXITED(status))
self.assertEqual(os.WEXITSTATUS(status), 0)
def test_db_lock3(self):
basedn = self.samdb.get_default_basedn()
(r1, w1) = os.pipe()
(r2, w2) = os.pipe()
pid = os.fork()
if pid == 0:
# In the child, close the main DB, re-open
del(self.samdb)
gc.collect()
self.samdb = SamDB(session_info=self.session,
lp=self.lp)
# We need to hold this iterator open to hold the all-record lock.
res = self.samdb.search_iterator()
os.write(w2, b"start")
if (os.read(r1, 7) != b"started"):
os._exit(1)
os.write(w2, b"add")
if (os.read(r1, 5) != b"added"):
os._exit(2)
# Wait 2 seconds to block prepare_commit() in the child.
os.write(w2, b"prepare")
time.sleep(2)
# Release the locks
for l in res:
pass
if (os.read(r1, 8) != b"prepared"):
os._exit(3)
os._exit(0)
# We can start the transaction during the search
# because both just grab the all-record read lock.
self.assertEqual(os.read(r2, 5), b"start")
self.samdb.transaction_start()
os.write(w1, b"started")
self.assertEqual(os.read(r2, 3), b"add")
# This will end up in the top level db
dn = "@DSDB_LOCK_TEST"
self.samdb.add({
"dn": dn})
self.samdb.delete(dn)
os.write(w1, b"added")
# Obtain a write lock, this will block until
# the child releases the read lock.
self.assertEqual(os.read(r2, 7), b"prepare")
start = time.time()
self.samdb.transaction_prepare_commit()
end = time.time()
self.assertGreater(end - start, 1.9)
os.write(w1, b"prepared")
# Drop the write lock
self.samdb.transaction_cancel()
(got_pid, status) = os.waitpid(pid, 0)
self.assertTrue(os.WIFEXITED(status))
self.assertEqual(os.WEXITSTATUS(status), 0)
self.assertEqual(got_pid, pid)
def _test_full_db_lock1(self, backend_path):
(r1, w1) = os.pipe()
pid = os.fork()
if pid == 0:
# In the child, close the main DB, re-open just one DB
del(self.samdb)
gc.collect()
backenddb = ldb.Ldb(backend_path)
backenddb.transaction_start()
backenddb.add({"dn": "@DSDB_LOCK_TEST"})
backenddb.delete("@DSDB_LOCK_TEST")
# Obtain a write lock
backenddb.transaction_prepare_commit()
os.write(w1, b"prepared")
time.sleep(2)
# Drop the write lock
backenddb.transaction_cancel()
os._exit(0)
self.assertEqual(os.read(r1, 8), b"prepared")
start = time.time()
# We need to hold this iterator open to hold the all-record lock.
res = self.samdb.search_iterator()
# This should take at least 2 seconds because the transaction
# has a write lock on one backend db open
end = time.time()
self.assertGreater(end - start, 1.9)
# Release the locks
for l in res:
pass
(got_pid, status) = os.waitpid(pid, 0)
self.assertEqual(got_pid, pid)
self.assertTrue(os.WIFEXITED(status))
self.assertEqual(os.WEXITSTATUS(status), 0)
def test_full_db_lock1(self):
basedn = self.samdb.get_default_basedn()
backend_filename = "%s.ldb" % basedn.get_casefold()
backend_subpath = os.path.join("sam.ldb.d",
backend_filename)
backend_path = self.lp.private_path(backend_subpath)
self._test_full_db_lock1(backend_path)
def test_full_db_lock1_config(self):
basedn = self.samdb.get_config_basedn()
backend_filename = "%s.ldb" % basedn.get_casefold()
backend_subpath = os.path.join("sam.ldb.d",
backend_filename)
backend_path = self.lp.private_path(backend_subpath)
self._test_full_db_lock1(backend_path)
def _test_full_db_lock2(self, backend_path):
(r1, w1) = os.pipe()
(r2, w2) = os.pipe()
pid = os.fork()
if pid == 0:
# In the child, close the main DB, re-open
del(self.samdb)
gc.collect()
self.samdb = SamDB(session_info=self.session,
lp=self.lp)
# We need to hold this iterator open to hold the all-record lock.
res = self.samdb.search_iterator()
os.write(w2, b"start")
if (os.read(r1, 7) != b"started"):
os._exit(1)
os.write(w2, b"add")
if (os.read(r1, 5) != b"added"):
os._exit(2)
# Wait 2 seconds to block prepare_commit() in the child.
os.write(w2, b"prepare")
time.sleep(2)
# Release the locks
for l in res:
pass
if (os.read(r1, 8) != b"prepared"):
os._exit(3)
os._exit(0)
# In the parent, close the main DB, re-open just one DB
del(self.samdb)
gc.collect()
backenddb = ldb.Ldb(backend_path)
# We can start the transaction during the search
# because both just grab the all-record read lock.
self.assertEqual(os.read(r2, 5), b"start")
backenddb.transaction_start()
os.write(w1, b"started")
self.assertEqual(os.read(r2, 3), b"add")
backenddb.add({"dn": "@DSDB_LOCK_TEST"})
backenddb.delete("@DSDB_LOCK_TEST")
os.write(w1, b"added")
# Obtain a write lock, this will block until
# the child releases the read lock.
self.assertEqual(os.read(r2, 7), b"prepare")
start = time.time()
backenddb.transaction_prepare_commit()
end = time.time()
try:
self.assertGreater(end - start, 1.9)
except:
raise
finally:
os.write(w1, b"prepared")
# Drop the write lock
backenddb.transaction_cancel()
(got_pid, status) = os.waitpid(pid, 0)
self.assertEqual(got_pid, pid)
self.assertTrue(os.WIFEXITED(status))
self.assertEqual(os.WEXITSTATUS(status), 0)
def test_full_db_lock2(self):
basedn = self.samdb.get_default_basedn()
backend_filename = "%s.ldb" % basedn.get_casefold()
backend_subpath = os.path.join("sam.ldb.d",
backend_filename)
backend_path = self.lp.private_path(backend_subpath)
self._test_full_db_lock2(backend_path)
def test_full_db_lock2_config(self):
basedn = self.samdb.get_config_basedn()
backend_filename = "%s.ldb" % basedn.get_casefold()
backend_subpath = os.path.join("sam.ldb.d",
backend_filename)
backend_path = self.lp.private_path(backend_subpath)
self._test_full_db_lock2(backend_path)
|