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git.ipfire.org Git - thirdparty/glibc.git/blob - sysdeps/unix/sysv/linux/i386/lockf64.c
1 /* Copyright (C) 1994-2018 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>
25 /* lockf is a simplified interface to fcntl's locking facilities. */
28 lockf64 (int fd
, int cmd
, off64_t len64
)
34 memset ((char *) &fl64
, '\0', sizeof (fl64
));
35 fl64
.l_whence
= SEEK_CUR
;
42 /* Test the lock: return 0 if FD is unlocked or locked by this process;
43 return -1, set errno to EACCES, if another process holds the lock. */
44 fl64
.l_type
= F_RDLCK
;
45 INTERNAL_SYSCALL_DECL (err
);
46 result
= INTERNAL_SYSCALL (fcntl64
, err
, 3, fd
, F_GETLK64
, &fl64
);
47 if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result
, err
)))
48 return INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (result
,
50 if (fl64
.l_type
== F_UNLCK
|| fl64
.l_pid
== __getpid ())
52 return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES
);
54 fl64
.l_type
= F_UNLCK
;
58 fl64
.l_type
= F_WRLCK
;
62 fl64
.l_type
= F_WRLCK
;
67 return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL
);
69 return INLINE_SYSCALL (fcntl64
, 3, fd
, cmd64
, &fl64
);