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/*
* Amanda, The Advanced Maryland Automatic Network Disk Archiver
* Copyright (c) 1991-1998 University of Maryland at College Park
* All Rights Reserved.
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of U.M. not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. U.M. makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
* U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
* BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Authors: the Amanda Development Team. Its members are listed in a
* file named AUTHORS, in the root directory of this distribution.
*/
/* moved from amflock.c by Dustin J. Mitchell <dustin@zmanda.com> */
#include "amanda.h"
/* XPG4-UNIX (eg, SGI IRIX, DEC DU) has F_ULOCK instead of F_UNLOCK */
#if defined(F_ULOCK) && !defined(F_UNLOCK)
# define F_UNLOCK F_ULOCK
#endif
static int
lockf_lock(
int fd,
G_GNUC_UNUSED char *resource)
{
return lockf(fd, F_LOCK, (off_t)0);
}
static int
lockf_unlock(
int fd,
G_GNUC_UNUSED char *resource)
{
off_t pos;
/* unlock from here on */
if (lockf(fd, F_UNLOCK, (off_t)0) == -1) return -1;
/* unlock from bof to here */
pos = lseek(fd, (off_t)0, SEEK_CUR);
if (pos == (off_t)-1) {
if (errno == ESPIPE)
pos = (off_t)0;
else
return -1;
}
if (pos > (off_t)0) {
if (lockf(fd, F_UNLOCK, -pos) == -1)
return -1;
}
return 0;
}
amflock_impl_t amflock_lockf_impl = {
lockf_lock,
lockf_lock, /* no read-only support */
lockf_unlock,
"lockf"
};
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