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/* $Id: filelock-os2.cpp $ */
/** @file
* IPRT - File Locking, OS/2.
*/
/*
* Copyright (C) 2008-2020 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#define LOG_GROUP RTLOGGROUP_FILE
#include <errno.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
#include <iprt/file.h>
#include <iprt/assert.h>
#include <iprt/string.h>
#include <iprt/err.h>
#include <iprt/log.h>
#include "internal/file.h"
#include "internal/fs.h"
RTR3DECL(int) RTFileLock(RTFILE File, unsigned fLock, int64_t offLock, uint64_t cbLock)
{
Assert(offLock >= 0);
/* Check arguments. */
if (fLock & ~RTFILE_LOCK_MASK)
{
AssertMsgFailed(("Invalid fLock=%08X\n", fLock));
return VERR_INVALID_PARAMETER;
}
/*
* Validate offset.
*/
if ( sizeof(off_t) < sizeof(cbLock)
&& ( (offLock >> 32) != 0
|| (cbLock >> 32) != 0
|| ((offLock + cbLock) >> 32) != 0))
{
AssertMsgFailed(("64-bit file i/o not supported! offLock=%lld cbLock=%lld\n", offLock, cbLock));
return VERR_NOT_SUPPORTED;
}
/* Prepare flock structure. */
struct flock fl;
Assert(RTFILE_LOCK_WRITE);
fl.l_type = (fLock & RTFILE_LOCK_WRITE) ? F_WRLCK : F_RDLCK;
fl.l_whence = SEEK_SET;
fl.l_start = (off_t)offLock;
fl.l_len = (off_t)cbLock;
fl.l_pid = 0;
Assert(RTFILE_LOCK_WAIT);
if (fcntl(RTFileToNative(File), (fLock & RTFILE_LOCK_WAIT) ? F_SETLKW : F_SETLK, &fl) >= 0)
return VINF_SUCCESS;
int iErr = errno;
if ( iErr == EAGAIN
|| iErr == EACCES)
return VERR_FILE_LOCK_VIOLATION;
return RTErrConvertFromErrno(iErr);
}
RTR3DECL(int) RTFileChangeLock(RTFILE File, unsigned fLock, int64_t offLock, uint64_t cbLock)
{
/** @todo copied from ../win/fileio-win.cpp for now but a proper solution
* would probably be to modify kLIBC so that __fcntl_locking() first
* assumes a change lock request is made (e.g. the same region was
* previously F_RDLCK'ed and now needs to be F_WRLCK'ed or vice versa) and
* tries to use atomic locking, and only if it fails, it does the regular
* lock procedure. The alternative is to use DosSetFileLocks directly here
* which basically means copy-pasting the __fcntl_locking() source
* code :) Note that the first attempt to call RTFileLock() below assumes
* that kLIBC is patched as described above one day and gives it a chance;
* on failure, we fall back to the Win-like unlock-then-lock approach. */
int rc = RTFileLock(File, fLock, offLock, cbLock);
if (RT_FAILURE(rc) && rc != VERR_FILE_LOCK_VIOLATION)
return rc;
/* Check arguments. */
if (fLock & ~RTFILE_LOCK_MASK)
{
AssertMsgFailed(("Invalid fLock=%08X\n", fLock));
return VERR_INVALID_PARAMETER;
}
/* Remove old lock. */
rc = RTFileUnlock(File, offLock, cbLock);
if (RT_FAILURE(rc))
return rc;
/* Set new lock. */
rc = RTFileLock(File, fLock, offLock, cbLock);
if (RT_SUCCESS(rc))
return rc;
/* Try to restore old lock. */
unsigned fLockOld = (fLock & RTFILE_LOCK_WRITE) ? fLock & ~RTFILE_LOCK_WRITE : fLock | RTFILE_LOCK_WRITE;
rc = RTFileLock(File, fLockOld, offLock, cbLock);
if (RT_SUCCESS(rc))
return VERR_FILE_LOCK_VIOLATION;
else
return VERR_FILE_LOCK_LOST;
}
RTR3DECL(int) RTFileUnlock(RTFILE File, int64_t offLock, uint64_t cbLock)
{
Assert(offLock >= 0);
/*
* Validate offset.
*/
if ( sizeof(off_t) < sizeof(cbLock)
&& ( (offLock >> 32) != 0
|| (cbLock >> 32) != 0
|| ((offLock + cbLock) >> 32) != 0))
{
AssertMsgFailed(("64-bit file i/o not supported! offLock=%lld cbLock=%lld\n", offLock, cbLock));
return VERR_NOT_SUPPORTED;
}
/* Prepare flock structure. */
struct flock fl;
fl.l_type = F_UNLCK;
fl.l_whence = SEEK_SET;
fl.l_start = (off_t)offLock;
fl.l_len = (off_t)cbLock;
fl.l_pid = 0;
if (fcntl(RTFileToNative(File), F_SETLK, &fl) >= 0)
return VINF_SUCCESS;
/** @todo check error codes for non existing lock. */
int iErr = errno;
if ( iErr == EAGAIN
|| iErr == EACCES)
return VERR_FILE_LOCK_VIOLATION;
return RTErrConvertFromErrno(iErr);
}
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