Another step on our continuing quest to switch to byte-based interfaces. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
279 lines
8.6 KiB
C
279 lines
8.6 KiB
C
/* BlockDriver implementation for "raw"
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*
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* Copyright (C) 2010, 2013, Red Hat, Inc.
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* Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com>
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* Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com>
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*
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* Author:
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* Laszlo Ersek <lersek@redhat.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "block/block_int.h"
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#include "qapi/error.h"
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#include "qemu/option.h"
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static QemuOptsList raw_create_opts = {
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.name = "raw-create-opts",
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.head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
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.desc = {
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{
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.name = BLOCK_OPT_SIZE,
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.type = QEMU_OPT_SIZE,
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.help = "Virtual disk size"
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},
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{ /* end of list */ }
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}
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};
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static int raw_reopen_prepare(BDRVReopenState *reopen_state,
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BlockReopenQueue *queue, Error **errp)
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{
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return 0;
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}
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static int coroutine_fn raw_co_readv(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, QEMUIOVector *qiov)
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{
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BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
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return bdrv_co_readv(bs->file->bs, sector_num, nb_sectors, qiov);
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}
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static int coroutine_fn
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raw_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
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QEMUIOVector *qiov, int flags)
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{
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void *buf = NULL;
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BlockDriver *drv;
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QEMUIOVector local_qiov;
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int ret;
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if (bs->probed && sector_num == 0) {
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/* As long as these conditions are true, we can't get partial writes to
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* the probe buffer and can just directly check the request. */
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QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
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QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
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if (nb_sectors == 0) {
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/* qemu_iovec_to_buf() would fail, but we want to return success
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* instead of -EINVAL in this case. */
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return 0;
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}
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buf = qemu_try_blockalign(bs->file->bs, 512);
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if (!buf) {
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ret = -ENOMEM;
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goto fail;
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}
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ret = qemu_iovec_to_buf(qiov, 0, buf, 512);
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if (ret != 512) {
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ret = -EINVAL;
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goto fail;
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}
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drv = bdrv_probe_all(buf, 512, NULL);
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if (drv != bs->drv) {
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ret = -EPERM;
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goto fail;
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}
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/* Use the checked buffer, a malicious guest might be overwriting its
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* original buffer in the background. */
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qemu_iovec_init(&local_qiov, qiov->niov + 1);
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qemu_iovec_add(&local_qiov, buf, 512);
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qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512);
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qiov = &local_qiov;
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}
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BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
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ret = bdrv_co_pwritev(bs->file->bs, sector_num * BDRV_SECTOR_SIZE,
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nb_sectors * BDRV_SECTOR_SIZE, qiov, flags);
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fail:
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if (qiov == &local_qiov) {
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qemu_iovec_destroy(&local_qiov);
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}
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qemu_vfree(buf);
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return ret;
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}
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static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
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int64_t sector_num,
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int nb_sectors, int *pnum,
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BlockDriverState **file)
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{
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*pnum = nb_sectors;
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*file = bs->file->bs;
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return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
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(sector_num << BDRV_SECTOR_BITS);
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}
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static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
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int64_t offset, int count,
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BdrvRequestFlags flags)
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{
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return bdrv_co_pwrite_zeroes(bs->file->bs, offset, count, flags);
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}
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static int coroutine_fn raw_co_discard(BlockDriverState *bs,
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int64_t sector_num, int nb_sectors)
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{
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return bdrv_co_discard(bs->file->bs, sector_num, nb_sectors);
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}
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static int64_t raw_getlength(BlockDriverState *bs)
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{
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return bdrv_getlength(bs->file->bs);
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}
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static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
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{
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return bdrv_get_info(bs->file->bs, bdi);
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}
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static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
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{
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bs->bl = bs->file->bs->bl;
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}
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static int raw_truncate(BlockDriverState *bs, int64_t offset)
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{
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return bdrv_truncate(bs->file->bs, offset);
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}
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static int raw_media_changed(BlockDriverState *bs)
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{
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return bdrv_media_changed(bs->file->bs);
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}
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static void raw_eject(BlockDriverState *bs, bool eject_flag)
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{
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bdrv_eject(bs->file->bs, eject_flag);
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}
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static void raw_lock_medium(BlockDriverState *bs, bool locked)
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{
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bdrv_lock_medium(bs->file->bs, locked);
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}
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static BlockAIOCB *raw_aio_ioctl(BlockDriverState *bs,
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unsigned long int req, void *buf,
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BlockCompletionFunc *cb,
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void *opaque)
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{
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return bdrv_aio_ioctl(bs->file->bs, req, buf, cb, opaque);
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}
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static int raw_has_zero_init(BlockDriverState *bs)
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{
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return bdrv_has_zero_init(bs->file->bs);
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}
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static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
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{
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Error *local_err = NULL;
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int ret;
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ret = bdrv_create_file(filename, opts, &local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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}
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return ret;
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}
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static int raw_open(BlockDriverState *bs, QDict *options, int flags,
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Error **errp)
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{
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bs->sg = bs->file->bs->sg;
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bs->supported_write_flags = BDRV_REQ_FUA;
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bs->supported_zero_flags = BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP;
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if (bs->probed && !bdrv_is_read_only(bs)) {
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fprintf(stderr,
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"WARNING: Image format was not specified for '%s' and probing "
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"guessed raw.\n"
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" Automatically detecting the format is dangerous for "
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"raw images, write operations on block 0 will be restricted.\n"
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" Specify the 'raw' format explicitly to remove the "
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"restrictions.\n",
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bs->file->bs->filename);
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}
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return 0;
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}
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static void raw_close(BlockDriverState *bs)
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{
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}
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static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
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{
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/* smallest possible positive score so that raw is used if and only if no
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* other block driver works
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*/
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return 1;
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}
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static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
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{
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return bdrv_probe_blocksizes(bs->file->bs, bsz);
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}
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static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
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{
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return bdrv_probe_geometry(bs->file->bs, geo);
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}
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BlockDriver bdrv_raw = {
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.format_name = "raw",
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.bdrv_probe = &raw_probe,
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.bdrv_reopen_prepare = &raw_reopen_prepare,
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.bdrv_open = &raw_open,
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.bdrv_close = &raw_close,
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.bdrv_create = &raw_create,
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.bdrv_co_readv = &raw_co_readv,
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.bdrv_co_writev_flags = &raw_co_writev_flags,
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.bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
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.bdrv_co_discard = &raw_co_discard,
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.bdrv_co_get_block_status = &raw_co_get_block_status,
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.bdrv_truncate = &raw_truncate,
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.bdrv_getlength = &raw_getlength,
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.has_variable_length = true,
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.bdrv_get_info = &raw_get_info,
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.bdrv_refresh_limits = &raw_refresh_limits,
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.bdrv_probe_blocksizes = &raw_probe_blocksizes,
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.bdrv_probe_geometry = &raw_probe_geometry,
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.bdrv_media_changed = &raw_media_changed,
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.bdrv_eject = &raw_eject,
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.bdrv_lock_medium = &raw_lock_medium,
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.bdrv_aio_ioctl = &raw_aio_ioctl,
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.create_opts = &raw_create_opts,
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.bdrv_has_zero_init = &raw_has_zero_init
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};
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static void bdrv_raw_init(void)
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{
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bdrv_register(&bdrv_raw);
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}
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block_init(bdrv_raw_init);
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