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qemu/block/raw-win32.c
Fam Zheng b04b6b6ec3 block: Print its file name if backing file opening failed 
If backing file doesn't exist, the error message is confusing and
misleading:

    $ qemu /tmp/a.qcow2
    qemu: could not open disk image /tmp/a.qcow2: Could not open file: No
    such file or directory

But...

    $ ls /tmp/a.qcow2
    /tmp/a.qcow2

    $ qemu-img info /tmp/a.qcow2
    image: /tmp/a.qcow2
    file format: qcow2
    virtual size: 8.0G (8589934592 bytes)
    disk size: 196K
    cluster_size: 65536
    backing file: /tmp/b.qcow2

Because...

    $ ls /tmp/b.qcow2
    ls: cannot access /tmp/b.qcow2: No such file or directory

This is not intuitive. It's better to have the missing file's name in
the error message. With this patch:

    $ qemu-io -c 'read 0 512' /tmp/a.qcow2
    qemu-io: can't open device /tmp/a.qcow2: Could not open backing
    file: Could not open '/stor/vm/arch.raw': No such file or directory
    no file open, try 'help open'

Which is a little bit better.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-11-14 13:09:06 +01:00

632 lines
17 KiB
C
Raw Blame History

/*
* Block driver for RAW files (win32)
*
* Copyright (c) 2006 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "qemu/timer.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "raw-aio.h"
#include "trace.h"
#include "block/thread-pool.h"
#include "qemu/iov.h"
#include <windows.h>
#include <winioctl.h>
#define FTYPE_FILE 0
#define FTYPE_CD 1
#define FTYPE_HARDDISK 2
static QEMUWin32AIOState *aio;
typedef struct RawWin32AIOData {
BlockDriverState *bs;
HANDLE hfile;
struct iovec *aio_iov;
int aio_niov;
size_t aio_nbytes;
off64_t aio_offset;
int aio_type;
} RawWin32AIOData;
typedef struct BDRVRawState {
HANDLE hfile;
int type;
char drive_path[16]; /* format: "d:\" */
QEMUWin32AIOState *aio;
} BDRVRawState;
/*
* Read/writes the data to/from a given linear buffer.
*
* Returns the number of bytes handles or -errno in case of an error. Short
* reads are only returned if the end of the file is reached.
*/
static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
{
size_t offset = 0;
int i;
for (i = 0; i < aiocb->aio_niov; i++) {
OVERLAPPED ov;
DWORD ret, ret_count, len;
memset(&ov, 0, sizeof(ov));
ov.Offset = (aiocb->aio_offset + offset);
ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
len = aiocb->aio_iov[i].iov_len;
if (aiocb->aio_type & QEMU_AIO_WRITE) {
ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
len, &ret_count, &ov);
} else {
ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
len, &ret_count, &ov);
}
if (!ret) {
ret_count = 0;
}
if (ret_count != len) {
offset += ret_count;
break;
}
offset += len;
}
return offset;
}
static int aio_worker(void *arg)
{
RawWin32AIOData *aiocb = arg;
ssize_t ret = 0;
size_t count;
switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
case QEMU_AIO_READ:
count = handle_aiocb_rw(aiocb);
if (count < aiocb->aio_nbytes && aiocb->bs->growable) {
/* A short read means that we have reached EOF. Pad the buffer
* with zeros for bytes after EOF. */
iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
0, aiocb->aio_nbytes - count);
count = aiocb->aio_nbytes;
}
if (count == aiocb->aio_nbytes) {
ret = 0;
} else {
ret = -EINVAL;
}
break;
case QEMU_AIO_WRITE:
count = handle_aiocb_rw(aiocb);
if (count == aiocb->aio_nbytes) {
count = 0;
} else {
count = -EINVAL;
}
break;
case QEMU_AIO_FLUSH:
if (!FlushFileBuffers(aiocb->hfile)) {
return -EIO;
}
break;
default:
fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
ret = -EINVAL;
break;
}
g_slice_free(RawWin32AIOData, aiocb);
return ret;
}
static BlockDriverAIOCB *paio_submit(BlockDriverState *bs, HANDLE hfile,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque, int type)
{
RawWin32AIOData *acb = g_slice_new(RawWin32AIOData);
ThreadPool *pool;
acb->bs = bs;
acb->hfile = hfile;
acb->aio_type = type;
if (qiov) {
acb->aio_iov = qiov->iov;
acb->aio_niov = qiov->niov;
}
acb->aio_nbytes = nb_sectors * 512;
acb->aio_offset = sector_num * 512;
trace_paio_submit(acb, opaque, sector_num, nb_sectors, type);
pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
}
int qemu_ftruncate64(int fd, int64_t length)
{
LARGE_INTEGER li;
DWORD dw;
LONG high;
HANDLE h;
BOOL res;
if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
return -1;
h = (HANDLE)_get_osfhandle(fd);
/* get current position, ftruncate do not change position */
li.HighPart = 0;
li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
return -1;
}
high = length >> 32;
dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
return -1;
}
res = SetEndOfFile(h);
/* back to old position */
SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
return res ? 0 : -1;
}
static int set_sparse(int fd)
{
DWORD returned;
return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
NULL, 0, NULL, 0, &returned, NULL);
}
static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped)
{
assert(access_flags != NULL);
assert(overlapped != NULL);
if (flags & BDRV_O_RDWR) {
*access_flags = GENERIC_READ | GENERIC_WRITE;
} else {
*access_flags = GENERIC_READ;
}
*overlapped = FILE_ATTRIBUTE_NORMAL;
if (flags & BDRV_O_NATIVE_AIO) {
*overlapped |= FILE_FLAG_OVERLAPPED;
}
if (flags & BDRV_O_NOCACHE) {
*overlapped |= FILE_FLAG_NO_BUFFERING;
}
}
static QemuOptsList raw_runtime_opts = {
.name = "raw",
.head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
.desc = {
{
.name = "filename",
.type = QEMU_OPT_STRING,
.help = "File name of the image",
},
{ /* end of list */ }
},
};
static int raw_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVRawState *s = bs->opaque;
int access_flags;
DWORD overlapped;
QemuOpts *opts;
Error *local_err = NULL;
const char *filename;
int ret;
s->type = FTYPE_FILE;
opts = qemu_opts_create_nofail(&raw_runtime_opts);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
filename = qemu_opt_get(opts, "filename");
raw_parse_flags(flags, &access_flags, &overlapped);
if ((flags & BDRV_O_NATIVE_AIO) && aio == NULL) {
aio = win32_aio_init();
if (aio == NULL) {
error_setg(errp, "Could not initialize AIO");
ret = -EINVAL;
goto fail;
}
}
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
OPEN_EXISTING, overlapped, NULL);
if (s->hfile == INVALID_HANDLE_VALUE) {
int err = GetLastError();
if (err == ERROR_ACCESS_DENIED) {
ret = -EACCES;
} else {
ret = -EINVAL;
}
goto fail;
}
if (flags & BDRV_O_NATIVE_AIO) {
ret = win32_aio_attach(aio, s->hfile);
if (ret < 0) {
CloseHandle(s->hfile);
error_setg_errno(errp, -ret, "Could not enable AIO");
goto fail;
}
s->aio = aio;
}
ret = 0;
fail:
qemu_opts_del(opts);
return ret;
}
static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
if (s->aio) {
return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
nb_sectors, cb, opaque, QEMU_AIO_READ);
} else {
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_READ);
}
}
static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
if (s->aio) {
return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
nb_sectors, cb, opaque, QEMU_AIO_WRITE);
} else {
return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
cb, opaque, QEMU_AIO_WRITE);
}
}
static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
}
static void raw_close(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
CloseHandle(s->hfile);
}
static int raw_truncate(BlockDriverState *bs, int64_t offset)
{
BDRVRawState *s = bs->opaque;
LONG low, high;
DWORD dwPtrLow;
low = offset;
high = offset >> 32;
/*
* An error has occurred if the return value is INVALID_SET_FILE_POINTER
* and GetLastError doesn't return NO_ERROR.
*/
dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
fprintf(stderr, "SetFilePointer error: %lu\n", GetLastError());
return -EIO;
}
if (SetEndOfFile(s->hfile) == 0) {
fprintf(stderr, "SetEndOfFile error: %lu\n", GetLastError());
return -EIO;
}
return 0;
}
static int64_t raw_getlength(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
LARGE_INTEGER l;
ULARGE_INTEGER available, total, total_free;
DISK_GEOMETRY_EX dg;
DWORD count;
BOOL status;
switch(s->type) {
case FTYPE_FILE:
l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
return -EIO;
break;
case FTYPE_CD:
if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
return -EIO;
l.QuadPart = total.QuadPart;
break;
case FTYPE_HARDDISK:
status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
NULL, 0, &dg, sizeof(dg), &count, NULL);
if (status != 0) {
l = dg.DiskSize;
}
break;
default:
return -EIO;
}
return l.QuadPart;
}
static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
{
typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
DWORD * high);
get_compressed_t get_compressed;
struct _stati64 st;
const char *filename = bs->filename;
/* WinNT support GetCompressedFileSize to determine allocate size */
get_compressed =
(get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
"GetCompressedFileSizeA");
if (get_compressed) {
DWORD high, low;
low = get_compressed(filename, &high);
if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
return (((int64_t) high) << 32) + low;
}
}
if (_stati64(filename, &st) < 0) {
return -1;
}
return st.st_size;
}
static int raw_create(const char *filename, QEMUOptionParameter *options,
Error **errp)
{
int fd;
int64_t total_size = 0;
/* Read out options */
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
total_size = options->value.n / 512;
}
options++;
}
fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
0644);
if (fd < 0) {
error_setg_errno(errp, errno, "Could not create file");
return -EIO;
}
set_sparse(fd);
ftruncate(fd, total_size * 512);
qemu_close(fd);
return 0;
}
static QEMUOptionParameter raw_create_options[] = {
{
.name = BLOCK_OPT_SIZE,
.type = OPT_SIZE,
.help = "Virtual disk size"
},
{ NULL }
};
static BlockDriver bdrv_file = {
.format_name = "file",
.protocol_name = "file",
.instance_size = sizeof(BDRVRawState),
.bdrv_needs_filename = true,
.bdrv_file_open = raw_open,
.bdrv_close = raw_close,
.bdrv_create = raw_create,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
.bdrv_aio_flush = raw_aio_flush,
.bdrv_truncate = raw_truncate,
.bdrv_getlength = raw_getlength,
.bdrv_get_allocated_file_size
= raw_get_allocated_file_size,
.create_options = raw_create_options,
};
/***********************************************/
/* host device */
static int find_cdrom(char *cdrom_name, int cdrom_name_size)
{
char drives[256], *pdrv = drives;
UINT type;
memset(drives, 0, sizeof(drives));
GetLogicalDriveStrings(sizeof(drives), drives);
while(pdrv[0] != '\0') {
type = GetDriveType(pdrv);
switch(type) {
case DRIVE_CDROM:
snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
return 0;
break;
}
pdrv += lstrlen(pdrv) + 1;
}
return -1;
}
static int find_device_type(BlockDriverState *bs, const char *filename)
{
BDRVRawState *s = bs->opaque;
UINT type;
const char *p;
if (strstart(filename, "\\\\.\\", &p) ||
strstart(filename, "//./", &p)) {
if (stristart(p, "PhysicalDrive", NULL))
return FTYPE_HARDDISK;
snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
type = GetDriveType(s->drive_path);
switch (type) {
case DRIVE_REMOVABLE:
case DRIVE_FIXED:
return FTYPE_HARDDISK;
case DRIVE_CDROM:
return FTYPE_CD;
default:
return FTYPE_FILE;
}
} else {
return FTYPE_FILE;
}
}
static int hdev_probe_device(const char *filename)
{
if (strstart(filename, "/dev/cdrom", NULL))
return 100;
if (is_windows_drive(filename))
return 100;
return 0;
}
static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVRawState *s = bs->opaque;
int access_flags, create_flags;
int ret = 0;
DWORD overlapped;
char device_name[64];
Error *local_err = NULL;
const char *filename;
QemuOpts *opts = qemu_opts_create_nofail(&raw_runtime_opts);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto done;
}
filename = qemu_opt_get(opts, "filename");
if (strstart(filename, "/dev/cdrom", NULL)) {
if (find_cdrom(device_name, sizeof(device_name)) < 0) {
error_setg(errp, "Could not open CD-ROM drive");
ret = -ENOENT;
goto done;
}
filename = device_name;
} else {
/* transform drive letters into device name */
if (((filename[0] >= 'a' && filename[0] <= 'z') ||
(filename[0] >= 'A' && filename[0] <= 'Z')) &&
filename[1] == ':' && filename[2] == '\0') {
snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
filename = device_name;
}
}
s->type = find_device_type(bs, filename);
raw_parse_flags(flags, &access_flags, &overlapped);
create_flags = OPEN_EXISTING;
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
create_flags, overlapped, NULL);
if (s->hfile == INVALID_HANDLE_VALUE) {
int err = GetLastError();
if (err == ERROR_ACCESS_DENIED) {
ret = -EACCES;
} else {
ret = -EINVAL;
}
error_setg_errno(errp, -ret, "Could not open device");
goto done;
}
done:
qemu_opts_del(opts);
return ret;
}
static BlockDriver bdrv_host_device = {
.format_name = "host_device",
.protocol_name = "host_device",
.instance_size = sizeof(BDRVRawState),
.bdrv_needs_filename = true,
.bdrv_probe_device = hdev_probe_device,
.bdrv_file_open = hdev_open,
.bdrv_close = raw_close,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
.bdrv_aio_flush = raw_aio_flush,
.bdrv_getlength = raw_getlength,
.has_variable_length = true,
.bdrv_get_allocated_file_size
= raw_get_allocated_file_size,
};
static void bdrv_file_init(void)
{
bdrv_register(&bdrv_file);
bdrv_register(&bdrv_host_device);
}
block_init(bdrv_file_init);
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