qemu/block/raw_bsd.c

274 lines
8.4 KiB
C

/* BlockDriver implementation for "raw"
*
* Copyright (C) 2010, 2013, Red Hat, Inc.
* Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com>
* Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com>
*
* Author:
* Laszlo Ersek <lersek@redhat.com>
*
* 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/osdep.h"
#include "block/block_int.h"
#include "qemu/option.h"
static QemuOptsList raw_create_opts = {
.name = "raw-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
{ /* end of list */ }
}
};
static int raw_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
static int coroutine_fn raw_co_readv(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
return bdrv_co_readv(bs->file->bs, sector_num, nb_sectors, qiov);
}
static int coroutine_fn raw_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
void *buf = NULL;
BlockDriver *drv;
QEMUIOVector local_qiov;
int ret;
if (bs->probed && sector_num == 0) {
/* As long as these conditions are true, we can't get partial writes to
* the probe buffer and can just directly check the request. */
QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
if (nb_sectors == 0) {
/* qemu_iovec_to_buf() would fail, but we want to return success
* instead of -EINVAL in this case. */
return 0;
}
buf = qemu_try_blockalign(bs->file->bs, 512);
if (!buf) {
ret = -ENOMEM;
goto fail;
}
ret = qemu_iovec_to_buf(qiov, 0, buf, 512);
if (ret != 512) {
ret = -EINVAL;
goto fail;
}
drv = bdrv_probe_all(buf, 512, NULL);
if (drv != bs->drv) {
ret = -EPERM;
goto fail;
}
/* Use the checked buffer, a malicious guest might be overwriting its
* original buffer in the background. */
qemu_iovec_init(&local_qiov, qiov->niov + 1);
qemu_iovec_add(&local_qiov, buf, 512);
qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512);
qiov = &local_qiov;
}
BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
ret = bdrv_co_writev(bs->file->bs, sector_num, nb_sectors, qiov);
fail:
if (qiov == &local_qiov) {
qemu_iovec_destroy(&local_qiov);
}
qemu_vfree(buf);
return ret;
}
static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, int *pnum,
BlockDriverState **file)
{
*pnum = nb_sectors;
*file = bs->file->bs;
return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
(sector_num << BDRV_SECTOR_BITS);
}
static int coroutine_fn raw_co_write_zeroes(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
BdrvRequestFlags flags)
{
return bdrv_co_write_zeroes(bs->file->bs, sector_num, nb_sectors, flags);
}
static int coroutine_fn raw_co_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
return bdrv_co_discard(bs->file->bs, sector_num, nb_sectors);
}
static int64_t raw_getlength(BlockDriverState *bs)
{
return bdrv_getlength(bs->file->bs);
}
static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
return bdrv_get_info(bs->file->bs, bdi);
}
static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
{
bs->bl = bs->file->bs->bl;
}
static int raw_truncate(BlockDriverState *bs, int64_t offset)
{
return bdrv_truncate(bs->file->bs, offset);
}
static int raw_media_changed(BlockDriverState *bs)
{
return bdrv_media_changed(bs->file->bs);
}
static void raw_eject(BlockDriverState *bs, bool eject_flag)
{
bdrv_eject(bs->file->bs, eject_flag);
}
static void raw_lock_medium(BlockDriverState *bs, bool locked)
{
bdrv_lock_medium(bs->file->bs, locked);
}
static BlockAIOCB *raw_aio_ioctl(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockCompletionFunc *cb,
void *opaque)
{
return bdrv_aio_ioctl(bs->file->bs, req, buf, cb, opaque);
}
static int raw_has_zero_init(BlockDriverState *bs)
{
return bdrv_has_zero_init(bs->file->bs);
}
static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
{
Error *local_err = NULL;
int ret;
ret = bdrv_create_file(filename, opts, &local_err);
if (local_err) {
error_propagate(errp, local_err);
}
return ret;
}
static int raw_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
bs->sg = bs->file->bs->sg;
if (bs->probed && !bdrv_is_read_only(bs)) {
fprintf(stderr,
"WARNING: Image format was not specified for '%s' and probing "
"guessed raw.\n"
" Automatically detecting the format is dangerous for "
"raw images, write operations on block 0 will be restricted.\n"
" Specify the 'raw' format explicitly to remove the "
"restrictions.\n",
bs->file->bs->filename);
}
return 0;
}
static void raw_close(BlockDriverState *bs)
{
}
static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
{
/* smallest possible positive score so that raw is used if and only if no
* other block driver works
*/
return 1;
}
static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
{
return bdrv_probe_blocksizes(bs->file->bs, bsz);
}
static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
{
return bdrv_probe_geometry(bs->file->bs, geo);
}
BlockDriver bdrv_raw = {
.format_name = "raw",
.bdrv_probe = &raw_probe,
.bdrv_reopen_prepare = &raw_reopen_prepare,
.bdrv_open = &raw_open,
.bdrv_close = &raw_close,
.bdrv_create = &raw_create,
.bdrv_co_readv = &raw_co_readv,
.bdrv_co_writev = &raw_co_writev,
.bdrv_co_write_zeroes = &raw_co_write_zeroes,
.bdrv_co_discard = &raw_co_discard,
.bdrv_co_get_block_status = &raw_co_get_block_status,
.bdrv_truncate = &raw_truncate,
.bdrv_getlength = &raw_getlength,
.has_variable_length = true,
.bdrv_get_info = &raw_get_info,
.bdrv_refresh_limits = &raw_refresh_limits,
.bdrv_probe_blocksizes = &raw_probe_blocksizes,
.bdrv_probe_geometry = &raw_probe_geometry,
.bdrv_media_changed = &raw_media_changed,
.bdrv_eject = &raw_eject,
.bdrv_lock_medium = &raw_lock_medium,
.bdrv_aio_ioctl = &raw_aio_ioctl,
.create_opts = &raw_create_opts,
.bdrv_has_zero_init = &raw_has_zero_init
};
static void bdrv_raw_init(void)
{
bdrv_register(&bdrv_raw);
}
block_init(bdrv_raw_init);