mirror of https://github.com/openzfs/zfs.git
74 lines
1.9 KiB
C
74 lines
1.9 KiB
C
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/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include "nfs.h"
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static int nfs_lock_fd = -1;
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/*
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* nfs_exports_[lock|unlock] are used to guard against conconcurrent
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* updates to the exports file. Each protocol is responsible for
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* providing the necessary locking to ensure consistency.
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*/
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__attribute__((visibility("hidden"))) int
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nfs_exports_lock(const char *name)
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{
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int err;
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nfs_lock_fd = open(name, O_RDWR | O_CREAT | O_CLOEXEC, 0600);
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if (nfs_lock_fd == -1) {
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err = errno;
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fprintf(stderr, "failed to lock %s: %s\n", name, strerror(err));
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return (err);
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}
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if (flock(nfs_lock_fd, LOCK_EX) != 0) {
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err = errno;
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fprintf(stderr, "failed to lock %s: %s\n", name, strerror(err));
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(void) close(nfs_lock_fd);
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nfs_lock_fd = -1;
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return (err);
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}
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return (0);
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}
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__attribute__((visibility("hidden"))) void
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nfs_exports_unlock(const char *name)
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{
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verify(nfs_lock_fd > 0);
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if (flock(nfs_lock_fd, LOCK_UN) != 0) {
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fprintf(stderr, "failed to unlock %s: %s\n",
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name, strerror(errno));
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}
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(void) close(nfs_lock_fd);
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nfs_lock_fd = -1;
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}
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