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