VirtualBox

source: vbox/trunk/src/VBox/Runtime/r3/os2/filelock-os2.cpp@ 103914

Last change on this file since 103914 was 98103, checked in by vboxsync, 2 years ago

Copyright year updates by scm.

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1/* $Id: filelock-os2.cpp 98103 2023-01-17 14:15:46Z vboxsync $ */
2/** @file
3 * IPRT - File Locking, OS/2.
4 */
5
6/*
7 * Copyright (C) 2008-2023 Oracle and/or its affiliates.
8 *
9 * This file is part of VirtualBox base platform packages, as
10 * available from https://www.virtualbox.org.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation, in version 3 of the
15 * License.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, see <https://www.gnu.org/licenses>.
24 *
25 * The contents of this file may alternatively be used under the terms
26 * of the Common Development and Distribution License Version 1.0
27 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28 * in the VirtualBox distribution, in which case the provisions of the
29 * CDDL are applicable instead of those of the GPL.
30 *
31 * You may elect to license modified versions of this file under the
32 * terms and conditions of either the GPL or the CDDL or both.
33 *
34 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35 */
36
37
38/*********************************************************************************************************************************
39* Header Files *
40*********************************************************************************************************************************/
41#define LOG_GROUP RTLOGGROUP_FILE
42
43#include <errno.h>
44#include <sys/types.h>
45#include <sys/ioctl.h>
46#include <sys/fcntl.h>
47#include <fcntl.h>
48#include <unistd.h>
49#include <sys/time.h>
50
51#include <iprt/file.h>
52#include <iprt/assert.h>
53#include <iprt/string.h>
54#include <iprt/err.h>
55#include <iprt/log.h>
56#include "internal/file.h"
57#include "internal/fs.h"
58
59
60
61
62RTR3DECL(int) RTFileLock(RTFILE File, unsigned fLock, int64_t offLock, uint64_t cbLock)
63{
64 Assert(offLock >= 0);
65
66 /* Check arguments. */
67 if (fLock & ~RTFILE_LOCK_MASK)
68 {
69 AssertMsgFailed(("Invalid fLock=%08X\n", fLock));
70 return VERR_INVALID_PARAMETER;
71 }
72
73 /*
74 * Validate offset.
75 */
76 if ( sizeof(off_t) < sizeof(cbLock)
77 && ( (offLock >> 32) != 0
78 || (cbLock >> 32) != 0
79 || ((offLock + cbLock) >> 32) != 0))
80 {
81 AssertMsgFailed(("64-bit file i/o not supported! offLock=%lld cbLock=%lld\n", offLock, cbLock));
82 return VERR_NOT_SUPPORTED;
83 }
84
85 /* Prepare flock structure. */
86 struct flock fl;
87 Assert(RTFILE_LOCK_WRITE);
88 fl.l_type = (fLock & RTFILE_LOCK_WRITE) ? F_WRLCK : F_RDLCK;
89 fl.l_whence = SEEK_SET;
90 fl.l_start = (off_t)offLock;
91 fl.l_len = (off_t)cbLock;
92 fl.l_pid = 0;
93
94 Assert(RTFILE_LOCK_WAIT);
95 if (fcntl(RTFileToNative(File), (fLock & RTFILE_LOCK_WAIT) ? F_SETLKW : F_SETLK, &fl) >= 0)
96 return VINF_SUCCESS;
97
98 int iErr = errno;
99 if ( iErr == EAGAIN
100 || iErr == EACCES)
101 return VERR_FILE_LOCK_VIOLATION;
102
103 return RTErrConvertFromErrno(iErr);
104}
105
106
107RTR3DECL(int) RTFileChangeLock(RTFILE File, unsigned fLock, int64_t offLock, uint64_t cbLock)
108{
109 /** @todo copied from ../win/fileio-win.cpp for now but a proper solution
110 * would probably be to modify kLIBC so that __fcntl_locking() first
111 * assumes a change lock request is made (e.g. the same region was
112 * previously F_RDLCK'ed and now needs to be F_WRLCK'ed or vice versa) and
113 * tries to use atomic locking, and only if it fails, it does the regular
114 * lock procedure. The alternative is to use DosSetFileLocks directly here
115 * which basically means copy-pasting the __fcntl_locking() source
116 * code :) Note that the first attempt to call RTFileLock() below assumes
117 * that kLIBC is patched as described above one day and gives it a chance;
118 * on failure, we fall back to the Win-like unlock-then-lock approach. */
119
120 int rc = RTFileLock(File, fLock, offLock, cbLock);
121 if (RT_FAILURE(rc) && rc != VERR_FILE_LOCK_VIOLATION)
122 return rc;
123
124 /* Check arguments. */
125 if (fLock & ~RTFILE_LOCK_MASK)
126 {
127 AssertMsgFailed(("Invalid fLock=%08X\n", fLock));
128 return VERR_INVALID_PARAMETER;
129 }
130
131 /* Remove old lock. */
132 rc = RTFileUnlock(File, offLock, cbLock);
133 if (RT_FAILURE(rc))
134 return rc;
135
136 /* Set new lock. */
137 rc = RTFileLock(File, fLock, offLock, cbLock);
138 if (RT_SUCCESS(rc))
139 return rc;
140
141 /* Try to restore old lock. */
142 unsigned fLockOld = (fLock & RTFILE_LOCK_WRITE) ? fLock & ~RTFILE_LOCK_WRITE : fLock | RTFILE_LOCK_WRITE;
143 rc = RTFileLock(File, fLockOld, offLock, cbLock);
144 if (RT_SUCCESS(rc))
145 return VERR_FILE_LOCK_VIOLATION;
146 else
147 return VERR_FILE_LOCK_LOST;
148}
149
150
151RTR3DECL(int) RTFileUnlock(RTFILE File, int64_t offLock, uint64_t cbLock)
152{
153 Assert(offLock >= 0);
154
155 /*
156 * Validate offset.
157 */
158 if ( sizeof(off_t) < sizeof(cbLock)
159 && ( (offLock >> 32) != 0
160 || (cbLock >> 32) != 0
161 || ((offLock + cbLock) >> 32) != 0))
162 {
163 AssertMsgFailed(("64-bit file i/o not supported! offLock=%lld cbLock=%lld\n", offLock, cbLock));
164 return VERR_NOT_SUPPORTED;
165 }
166
167 /* Prepare flock structure. */
168 struct flock fl;
169 fl.l_type = F_UNLCK;
170 fl.l_whence = SEEK_SET;
171 fl.l_start = (off_t)offLock;
172 fl.l_len = (off_t)cbLock;
173 fl.l_pid = 0;
174
175 if (fcntl(RTFileToNative(File), F_SETLK, &fl) >= 0)
176 return VINF_SUCCESS;
177
178 /** @todo check error codes for non existing lock. */
179 int iErr = errno;
180 if ( iErr == EAGAIN
181 || iErr == EACCES)
182 return VERR_FILE_LOCK_VIOLATION;
183
184 return RTErrConvertFromErrno(iErr);
185}
186
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