1 /*
2 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
3 * Copyright (c) 1991-1998 University of Maryland at College Park
4 * Copyright (c) 2007-2013 Zmanda, Inc. All Rights Reserved.
5 * All Rights Reserved.
6 *
7 * Permission to use, copy, modify, distribute, and sell this software and its
8 * documentation for any purpose is hereby granted without fee, provided that
9 * the above copyright notice appear in all copies and that both that
10 * copyright notice and this permission notice appear in supporting
11 * documentation, and that the name of U.M. not be used in advertising or
12 * publicity pertaining to distribution of the software without specific,
13 * written prior permission. U.M. makes no representations about the
14 * suitability of this software for any purpose. It is provided "as is"
15 * without express or implied warranty.
16 *
17 * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
19 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
20 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
21 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
22 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 *
24 * Authors: the Amanda Development Team. Its members are listed in a
25 * file named AUTHORS, in the root directory of this distribution.
26 */
27
28 /* moved from amflock.c by Dustin J. Mitchell <dustin@zmanda.com> */
29
30 #include "amanda.h"
31
32 /* XPG4-UNIX (eg, SGI IRIX, DEC DU) has F_ULOCK instead of F_UNLOCK */
33 #if defined(F_ULOCK) && !defined(F_UNLOCK)
34 # define F_UNLOCK F_ULOCK
35 #endif
36
37 static int
lockf_lock(int fd,G_GNUC_UNUSED char * resource)38 lockf_lock(
39 int fd,
40 G_GNUC_UNUSED char *resource)
41 {
42 return lockf(fd, F_LOCK, (off_t)0);
43 }
44
45 static int
lockf_unlock(int fd,G_GNUC_UNUSED char * resource)46 lockf_unlock(
47 int fd,
48 G_GNUC_UNUSED char *resource)
49 {
50 off_t pos;
51
52 /* unlock from here on */
53 if (lockf(fd, F_UNLOCK, (off_t)0) == -1) return -1;
54
55 /* unlock from bof to here */
56 pos = lseek(fd, (off_t)0, SEEK_CUR);
57 if (pos == (off_t)-1) {
58 if (errno == ESPIPE)
59 pos = (off_t)0;
60 else
61 return -1;
62 }
63
64 if (pos > (off_t)0) {
65 if (lockf(fd, F_UNLOCK, -pos) == -1)
66 return -1;
67 }
68
69 return 0;
70 }
71
72 amflock_impl_t amflock_lockf_impl = {
73 lockf_lock,
74 lockf_lock, /* no read-only support */
75 lockf_unlock,
76 "lockf"
77 };
78