diff options
Diffstat (limited to 'src/VBox/Runtime/r3/os2/filelock-os2.cpp')
| -rw-r--r-- | src/VBox/Runtime/r3/os2/filelock-os2.cpp | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/os2/filelock-os2.cpp b/src/VBox/Runtime/r3/os2/filelock-os2.cpp new file mode 100644 index 00000000..8484249c --- /dev/null +++ b/src/VBox/Runtime/r3/os2/filelock-os2.cpp @@ -0,0 +1,176 @@ +/* $Id: filelock-os2.cpp $ */ +/** @file + * IPRT - File Locking, OS/2. + */ + +/* + * Copyright (C) 2008-2019 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); +} + |