diff options
| -rw-r--r-- | lib/portage/locks.py | 78 |
1 files changed, 65 insertions, 13 deletions
diff --git a/lib/portage/locks.py b/lib/portage/locks.py index a4e7ec53f..74c2c086a 100644 --- a/lib/portage/locks.py +++ b/lib/portage/locks.py @@ -1,5 +1,5 @@ # portage: Lock management code -# Copyright 2004-2014 Gentoo Foundation +# Copyright 2004-2019 Gentoo Authors # Distributed under the terms of the GNU General Public License v2 __all__ = ["lockdir", "unlockdir", "lockfile", "unlockfile", \ @@ -20,6 +20,7 @@ from portage.exception import (DirectoryNotFound, FileNotFound, InvalidData, TryAgain, OperationNotPermitted, PermissionDenied, ReadOnlyFileSystem) from portage.util import writemsg +from portage.util.install_mask import _raise_exc from portage.localization import _ if sys.hexversion >= 0x3000000: @@ -148,18 +149,17 @@ def lockfile(mypath, wantnewlockfile=0, unlinkfile=0, preexisting = os.path.exists(lockfilename) old_mask = os.umask(000) try: - try: - myfd = os.open(lockfilename, os.O_CREAT|os.O_RDWR, 0o660) - except OSError as e: - func_call = "open('%s')" % lockfilename - if e.errno == OperationNotPermitted.errno: - raise OperationNotPermitted(func_call) - elif e.errno == PermissionDenied.errno: - raise PermissionDenied(func_call) - elif e.errno == ReadOnlyFileSystem.errno: - raise ReadOnlyFileSystem(func_call) + while True: + try: + myfd = os.open(lockfilename, os.O_CREAT|os.O_RDWR, 0o660) + except OSError as e: + if e.errno in (errno.ENOENT, errno.ESTALE) and os.path.isdir(os.path.dirname(lockfilename)): + # Retry required for NFS (see bug 636798). + continue + else: + _raise_exc(e) else: - raise + break if not preexisting: try: @@ -273,7 +273,7 @@ def lockfile(mypath, wantnewlockfile=0, unlinkfile=0, if isinstance(lockfilename, basestring) and \ - myfd != HARDLINK_FD and _fstat_nlink(myfd) == 0: + myfd != HARDLINK_FD and _lockfile_was_removed(myfd, lockfilename): # The file was deleted on us... Keep trying to make one... os.close(myfd) writemsg(_("lockfile recurse\n"), 1) @@ -298,6 +298,58 @@ def lockfile(mypath, wantnewlockfile=0, unlinkfile=0, writemsg(str((lockfilename, myfd, unlinkfile)) + "\n", 1) return (lockfilename, myfd, unlinkfile, locking_method) + +def _lockfile_was_removed(lock_fd, lock_path): + """ + Check if lock_fd still refers to a file located at lock_path, since + the file may have been removed by a concurrent process that held the + lock earlier. This implementation includes support for NFS, where + stat is not reliable for removed files due to the default file + attribute cache behavior ('ac' mount option). + + @param lock_fd: an open file descriptor for a lock file + @type lock_fd: int + @param lock_path: path of lock file + @type lock_path: str + @rtype: bool + @return: True if lock_path exists and corresponds to lock_fd, False otherwise + """ + try: + fstat_st = os.fstat(lock_fd) + except OSError as e: + if e.errno not in (errno.ENOENT, errno.ESTALE): + _raise_exc(e) + return True + + # Since stat is not reliable for removed files on NFS with the default + # file attribute cache behavior ('ac' mount option), create a temporary + # hardlink in order to prove that the file path exists on the NFS server. + hardlink_path = hardlock_name(lock_path) + try: + os.unlink(hardlink_path) + except OSError as e: + if e.errno not in (errno.ENOENT, errno.ESTALE): + _raise_exc(e) + try: + try: + os.link(lock_path, hardlink_path) + except OSError as e: + if e.errno not in (errno.ENOENT, errno.ESTALE): + _raise_exc(e) + return True + + hardlink_stat = os.stat(hardlink_path) + if hardlink_stat.st_ino != fstat_st.st_ino or hardlink_stat.st_dev != fstat_st.st_dev: + return True + finally: + try: + os.unlink(hardlink_path) + except OSError as e: + if e.errno not in (errno.ENOENT, errno.ESTALE): + _raise_exc(e) + return False + + def _fstat_nlink(fd): """ @param fd: an open file descriptor |