diff options
Diffstat (limited to 'src/VBox/Runtime/r3/linux/RTFileCopyPartEx-linux.cpp')
| -rw-r--r-- | src/VBox/Runtime/r3/linux/RTFileCopyPartEx-linux.cpp | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/linux/RTFileCopyPartEx-linux.cpp b/src/VBox/Runtime/r3/linux/RTFileCopyPartEx-linux.cpp new file mode 100644 index 00000000..198df368 --- /dev/null +++ b/src/VBox/Runtime/r3/linux/RTFileCopyPartEx-linux.cpp @@ -0,0 +1,186 @@ +/* $Id: RTFileCopyPartEx-linux.cpp $ */ +/** @file + * IPRT - RTFileCopyPartEx, linux specific implementation. + */ + +/* + * Copyright (C) 2006-2020 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 * +*********************************************************************************************************************************/ +#include <iprt/file.h> +#include "internal/iprt.h" + +#include <iprt/asm.h> +#include <iprt/assert.h> +#include <iprt/err.h> + +#include <errno.h> +#include <unistd.h> +#include <sys/syscall.h> + +#ifndef __NR_copy_file_range +# if defined(RT_ARCH_X86) +# define __NR_copy_file_range 377 +# elif defined(RT_ARCH_AMD64) +# define __NR_copy_file_range 326 +# endif +#endif + + +#ifndef __NR_copy_file_range +# include "../../generic/RTFileCopyPartEx-generic.cpp" +#else /* __NR_copy_file_range - whole file */ +/* Include the generic code as a fallback since copy_file_range is rather new . */ +# define IPRT_FALLBACK_VERSION +# include "../../generic/RTFileCopyPartEx-generic.cpp" +# undef IPRT_FALLBACK_VERSION + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +static int32_t volatile g_fCopyFileRangeSupported = -1; + + +DECLINLINE(loff_t) +MyCopyFileRangeSysCall(int fdIn, loff_t *poffIn, int fdOut, loff_t *poffOut, size_t cbChunk, unsigned int fFlags) +{ + return syscall(__NR_copy_file_range, fdIn, poffIn, fdOut, poffOut, cbChunk, fFlags); +} + + +DECL_NO_INLINE(static, bool) HasCopyFileRangeSyscallSlow(void) +{ + errno = 0; + MyCopyFileRangeSysCall(-1, NULL, -1, NULL, 4096, 0); + if (errno != ENOSYS) + { + ASMAtomicWriteS32(&g_fCopyFileRangeSupported, 1); + return true; + } + ASMAtomicWriteS32(&g_fCopyFileRangeSupported, 0); + return false; +} + +DECLINLINE(bool) HasCopyFileRangeSyscall(void) +{ + int32_t i = ASMAtomicUoReadS32(&g_fCopyFileRangeSupported); + if (i != -1) + return i == 1; + return HasCopyFileRangeSyscallSlow(); +} + + + +RTDECL(int) RTFileCopyPartPrep(PRTFILECOPYPARTBUFSTATE pBufState, uint64_t cbToCopy) +{ + if (HasCopyFileRangeSyscall()) + { + pBufState->iAllocType = -42; + pBufState->pbBuf = NULL; + pBufState->cbBuf = 0; + pBufState->uMagic = RTFILECOPYPARTBUFSTATE_MAGIC; + return VINF_SUCCESS; + } + return rtFileCopyPartPrepFallback(pBufState, cbToCopy); +} + + +RTDECL(void) RTFileCopyPartCleanup(PRTFILECOPYPARTBUFSTATE pBufState) +{ + return rtFileCopyPartCleanupFallback(pBufState); +} + + +RTDECL(int) RTFileCopyPartEx(RTFILE hFileSrc, RTFOFF offSrc, RTFILE hFileDst, RTFOFF offDst, uint64_t cbToCopy, + uint32_t fFlags, PRTFILECOPYPARTBUFSTATE pBufState, uint64_t *pcbCopied) +{ + /* + * Validate input. + */ + if (pcbCopied) + *pcbCopied = 0; + AssertReturn(pBufState->uMagic == RTFILECOPYPARTBUFSTATE_MAGIC, VERR_INVALID_FLAGS); + if (pBufState->iAllocType == -42) + { /* more and more likely as time goes */ } + else + return rtFileCopyPartExFallback(hFileSrc, offSrc, hFileDst, offDst, cbToCopy, fFlags, pBufState, pcbCopied); + AssertReturn(offSrc >= 0, VERR_NEGATIVE_SEEK); + AssertReturn(offDst >= 0, VERR_NEGATIVE_SEEK); + AssertReturn(!fFlags, VERR_INVALID_FLAGS); + + /* + * If nothing to copy, return right away. + */ + if (!cbToCopy) + return VINF_SUCCESS; + + /* + * Do the copying. + */ + uint64_t cbCopied = 0; + int rc = VINF_SUCCESS; + do + { + size_t cbThisCopy = (size_t)RT_MIN(cbToCopy - cbCopied, _1G); + loff_t offThisDst = offSrc + cbCopied; + loff_t offThisSrc = offDst + cbCopied; + ssize_t cbActual = MyCopyFileRangeSysCall((int)RTFileToNative(hFileSrc), &offThisSrc, + (int)RTFileToNative(hFileDst), &offThisDst, + cbThisCopy, 0); + if (cbActual < 0) + { + rc = errno; + Assert(rc != 0); + rc = rc != 0 ? RTErrConvertFromErrno(rc) : VERR_READ_ERROR; + if (rc != VERR_NOT_SAME_DEVICE || cbCopied != 0) + break; + + /* Fall back to generic implementation if the syscall refuses to handle the case. */ + rc = rtFileCopyPartPrepFallback(pBufState, cbToCopy); + if (RT_SUCCESS(rc)) + return rtFileCopyPartExFallback(hFileSrc, offSrc, hFileDst, offDst, cbToCopy, fFlags, pBufState, pcbCopied); + return rc; + } + Assert(offThisSrc == offSrc + (int64_t)cbCopied + cbActual); + Assert(offThisDst == offDst + (int64_t)cbCopied + cbActual); + + if (cbActual == 0) + { + if (!pcbCopied) + rc = VERR_EOF; + break; + } + + cbCopied += cbActual; + } while (cbCopied < cbToCopy); + + if (pcbCopied) + *pcbCopied = cbCopied; + + return rc; +} + +#endif /* __NR_copy_file_range */ + |