tobias/radicale
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

raise exception when locking the storage fails

Browse Source 
Previously it was silently ignored, which is dangerous when multiple instances of Radicale are running.
A configuration option to disable locking was added.
This commit is contained in:
Unrud 2017-06-01 11:21:22 +02:00
parent 17d03be27b
commit a18874fc59
3 changed files with 31 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
config
View File

@ -101,6 +101,10 @@
# Folder for storing local collections, created if not present # Folder for storing local collections, created if not present
#filesystem_folder = /var/lib/radicale/collections #filesystem_folder = /var/lib/radicale/collections
# Lock the storage. Never start multiple instances of Radicale or edit the
# storage externally while Radicale is running if disabled.
#filesystem_locking = True
# Sync all changes to disk during requests. (This can impair performance.) # Sync all changes to disk during requests. (This can impair performance.)
# Disabling it increases the risk of data loss, when the system crashes or # Disabling it increases the risk of data loss, when the system crashes or
# power fails! # power fails!

4
radicale/config.py
View File

@ -139,6 +139,10 @@ INITIAL_CONFIG = OrderedDict([
"value": "True", "value": "True",
"help": "sync all changes to filesystem during requests", "help": "sync all changes to filesystem during requests",
"type": bool}), "type": bool}),
("filesystem_locking", {
"value": "True",
"help": "lock the storage while accessing it",
"type": bool}),
("filesystem_close_lock_file", { ("filesystem_close_lock_file", {
"value": "False", "value": "False",
"help": "close the lock file when no more clients are waiting", "help": "close the lock file when no more clients are waiting",

31
radicale/storage.py
View File

@ -751,6 +751,10 @@ class Collection(BaseCollection):
@classmethod @classmethod
@contextmanager @contextmanager
def acquire_lock(cls, mode, user=None): def acquire_lock(cls, mode, user=None):
if not cls.configuration.getboolean("storage", "filesystem_locking"):
yield
return
def condition(): def condition():
if mode == "r": if mode == "r":
return not cls._writer return not cls._writer
@ -786,21 +790,27 @@ class Collection(BaseCollection):
# by arbitrary users # by arbitrary users
try: try:
os.chmod(lock_path, stat.S_IWUSR | stat.S_IRUSR) os.chmod(lock_path, stat.S_IWUSR | stat.S_IRUSR)
except OSError: except OSError as e:
cls.logger.debug("Failed to set permissions on lock file") cls.logger.info("Failed to set permissions on lock file:"
" %s", e, exc_info=True)
if not cls._lock_file_locked: if not cls._lock_file_locked:
if os.name == "nt": if os.name == "nt":
handle = msvcrt.get_osfhandle(cls._lock_file.fileno()) handle = msvcrt.get_osfhandle(cls._lock_file.fileno())
flags = LOCKFILE_EXCLUSIVE_LOCK if mode == "w" else 0 flags = LOCKFILE_EXCLUSIVE_LOCK if mode == "w" else 0
overlapped = Overlapped() overlapped = Overlapped()
if not lock_file_ex(handle, flags, 0, 1, 0, overlapped): if not lock_file_ex(handle, flags, 0, 1, 0, overlapped):
cls.logger.debug("Locking not supported") raise RuntimeError("Locking the storage failed: %s" %
ctypes.FormatError())
elif os.name == "posix": elif os.name == "posix":
_cmd = fcntl.LOCK_EX if mode == "w" else fcntl.LOCK_SH _cmd = fcntl.LOCK_EX if mode == "w" else fcntl.LOCK_SH
try: try:
fcntl.flock(cls._lock_file.fileno(), _cmd) fcntl.flock(cls._lock_file.fileno(), _cmd)
except OSError: except OSError as e:
cls.logger.debug("Locking not supported") raise RuntimeError("Locking the storage failed: %s" %
e) from e
else:
raise RuntimeError("Locking the storage failed: "
"Unsupported operating system")
cls._lock_file_locked = True cls._lock_file_locked = True
try: try:
yield yield
@ -822,12 +832,17 @@ class Collection(BaseCollection):
handle = msvcrt.get_osfhandle(cls._lock_file.fileno()) handle = msvcrt.get_osfhandle(cls._lock_file.fileno())
overlapped = Overlapped() overlapped = Overlapped()
if not unlock_file_ex(handle, 0, 1, 0, overlapped): if not unlock_file_ex(handle, 0, 1, 0, overlapped):
cls.logger.debug("Unlocking not supported") raise RuntimeError("Unlocking the storage failed: "
"%s" % ctypes.FormatError())
elif os.name == "posix": elif os.name == "posix":
try: try:
fcntl.flock(cls._lock_file.fileno(), fcntl.LOCK_UN) fcntl.flock(cls._lock_file.fileno(), fcntl.LOCK_UN)
except OSError: except OSError as e:
cls.logger.debug("Unlocking not supported") raise RuntimeError("Unlocking the storage failed: "
"%s" % e) from e
else:
raise RuntimeError("Unlocking the storage failed: "
"Unsupported operating system")
cls._lock_file_locked = False cls._lock_file_locked = False
if cls._waiters: if cls._waiters:
cls._waiters[0].notify() cls._waiters[0].notify()