1 /* Copyright (C) 1994-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
18 #include <sys/types.h>
24 /* lockf.c defines lockf64 as an alias if __OFF_T_MATCHES_OFF64_T. */
25 #ifndef __OFF_T_MATCHES_OFF64_T
27 /* lockf is a simplified interface to fcntl's locking facilities. */
30 lockf64 (int fd, int cmd, off64_t len64)
33 off_t len = (off_t) len64;
35 if (len64 != (off64_t) len)
37 /* We can't represent the length. */
38 __set_errno (EOVERFLOW);
42 memset ((char *) &fl, '\0', sizeof (fl));
44 /* lockf is always relative to the current file position. */
45 fl.l_whence = SEEK_CUR;
52 /* Test the lock: return 0 if FD is unlocked or locked by this process;
53 return -1, set errno to EACCES, if another process holds the lock. */
55 if (__fcntl (fd, F_GETLK, &fl) < 0)
57 if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ())
80 return __fcntl (fd, cmd, &fl);