x/swiftonfile
Code Issues Proposed changes

Merge "Handle non-blocking renames during object PUTs"

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This commit is contained in:
Jenkins 2016-06-14 17:36:19 +00:00 committed by Gerrit Code Review
commit 35601d4191
2 changed files with 38 additions and 7 deletions
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4
swiftonfile/swift/common/exceptions.py
View File

@ -36,3 +36,7 @@ class AlreadyExistsAsDir(SwiftOnFileFsException):
class AlreadyExistsAsFile(SwiftOnFileFsException):
pass
class DiskFileContainerDoesNotExist(SwiftOnFileFsException):
pass

41
swiftonfile/swift/obj/diskfile.py
View File

@ -27,7 +27,7 @@ from uuid import uuid4
from eventlet import sleep
from contextlib import contextmanager
from swiftonfile.swift.common.exceptions import AlreadyExistsAsFile, \
AlreadyExistsAsDir
AlreadyExistsAsDir, DiskFileContainerDoesNotExist
from swift.common.utils import ThreadPool, hash_path, \
normalize_timestamp, fallocate, Timestamp
from swift.common.exceptions import DiskFileNotExist, DiskFileError, \
@ -320,8 +320,13 @@ class DiskFileWriter(object):
try:
do_rename(self._tmppath, df._data_file)
except OSError as err:
if err.errno in (errno.ENOENT, errno.EIO) \
if err.errno in (errno.ENOENT, errno.EIO,
errno.EBUSY, errno.ESTALE) \
and attempts < MAX_RENAME_ATTEMPTS:
# Some versions of GlusterFS had rename() as non-blocking
# operation. So we check for STALE and EBUSY. This was
# fixed recently: http://review.gluster.org/#/c/13366/
# The comment that follows is for ENOENT and EIO...
# FIXME: Why either of these two error conditions is
# happening is unknown at this point. This might be a
# FUSE issue of some sort or a possible race
@ -411,7 +416,7 @@ class DiskFileWriter(object):
df._threadpool.force_run_in_thread(self._finalize_put, metadata)
# Avoid the unlink() system call as part of the mkstemp context
# Avoid the unlink() system call as part of the create context
# cleanup
self._tmppath = None
@ -579,6 +584,8 @@ class DiskFile(object):
self._is_dir = False
self._metadata = None
self._fd = None
# This fd attribute is not used in PUT path. fd used in PUT path
# is encapsulated inside DiskFileWriter object.
self._stat = None
# Don't store a value for data_file until we know it exists.
self._data_file = None
@ -884,6 +891,7 @@ class DiskFile(object):
# Assume the full directory path exists to the file already, and
# construct the proper name for the temporary file.
fd = None
attempts = 1
while True:
# To know more about why following temp file naming convention is
@ -911,7 +919,7 @@ class DiskFile(object):
if attempts >= MAX_OPEN_ATTEMPTS:
# We failed after N attempts to create the temporary
# file.
raise DiskFileError('DiskFile.mkstemp(): failed to'
raise DiskFileError('DiskFile.create(): failed to'
' successfully create a temporary file'
' without running into a name conflict'
' after %d of %d attempts for: %s' % (
@ -924,24 +932,41 @@ class DiskFile(object):
# FIXME: Possible FUSE issue or race condition, let's
# sleep on it and retry the operation.
_random_sleep()
logging.warn("DiskFile.mkstemp(): %s ... retrying in"
logging.warn("DiskFile.create(): %s ... retrying in"
" 0.1 secs", gerr)
attempts += 1
elif not self._obj_path:
# ENOENT
# No directory hierarchy and the create failed telling us
# the container or volume directory does not exist. This
# could be a FUSE issue or some race condition, so let's
# sleep a bit and retry.
# Handle race:
# This can be the issue when memcache has cached that the
# container exists. If someone removes the container dir
# from filesystem, it's not reflected in memcache. So
# swift reports that the container exists and this code
# tries to create a file in a directory that does not
# exist. However, it's wrong to create the container here.
_random_sleep()
logging.warn("DiskFile.mkstemp(): %s ... retrying in"
logging.warn("DiskFile.create(): %s ... retrying in"
" 0.1 secs", gerr)
attempts += 1
if attempts > 2:
# Ideally we would want to return 404 indicating that
# the container itself does not exist. Can't be done
# though as the caller won't catch DiskFileNotExist.
# We raise an exception with a meaningful name for
# correctness.
logging.warn("Container dir %s does not exist",
self._container_path)
raise DiskFileContainerDoesNotExist
elif attempts > 1:
# Got ENOENT after previously making the path. This could
# also be a FUSE issue or some race condition, nap and
# retry.
_random_sleep()
logging.warn("DiskFile.mkstemp(): %s ... retrying in"
logging.warn("DiskFile.create(): %s ... retrying in"
" 0.1 secs" % gerr)
attempts += 1
else:
@ -963,6 +988,8 @@ class DiskFile(object):
# Ensure it is properly owned before we make it available.
do_fchown(fd, self._uid, self._gid)
dw = DiskFileWriter(fd, tmppath, self)
# It's now the responsibility of DiskFileWriter to close this fd.
fd = None
yield dw
finally:
if dw: