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1dcaf52760
We need to implement .bdrv_has_zero_init_truncate() for every block driver that supports truncation and has a .bdrv_has_zero_init() implementation. Implement it the same way each driver implements .bdrv_has_zero_init(). This is at least not any more unsafe than what we had before. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
591 lines
18 KiB
C
591 lines
18 KiB
C
/* BlockDriver implementation for "raw" format driver
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*
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* Copyright (C) 2010-2016 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/module.h"
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#include "qemu/option.h"
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typedef struct BDRVRawState {
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uint64_t offset;
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uint64_t size;
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bool has_size;
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} BDRVRawState;
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static const char *const mutable_opts[] = { "offset", "size", NULL };
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static QemuOptsList raw_runtime_opts = {
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.name = "raw",
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.head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
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.desc = {
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{
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.name = "offset",
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.type = QEMU_OPT_SIZE,
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.help = "offset in the disk where the image starts",
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},
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{
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.name = "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 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_read_options(QDict *options, BlockDriverState *bs,
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BDRVRawState *s, Error **errp)
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{
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Error *local_err = NULL;
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QemuOpts *opts = NULL;
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int64_t real_size = 0;
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int ret;
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real_size = bdrv_getlength(bs->file->bs);
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if (real_size < 0) {
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error_setg_errno(errp, -real_size, "Could not get image size");
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return real_size;
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}
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opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
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qemu_opts_absorb_qdict(opts, options, &local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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ret = -EINVAL;
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goto end;
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}
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s->offset = qemu_opt_get_size(opts, "offset", 0);
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if (s->offset > real_size) {
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error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than "
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"size of the containing file (%" PRId64 ")",
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s->offset, real_size);
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ret = -EINVAL;
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goto end;
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}
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if (qemu_opt_find(opts, "size") != NULL) {
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s->size = qemu_opt_get_size(opts, "size", 0);
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s->has_size = true;
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} else {
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s->has_size = false;
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s->size = real_size - s->offset;
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}
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/* Check size and offset */
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if ((real_size - s->offset) < s->size) {
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error_setg(errp, "The sum of offset (%" PRIu64 ") and size "
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"(%" PRIu64 ") has to be smaller or equal to the "
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" actual size of the containing file (%" PRId64 ")",
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s->offset, s->size, real_size);
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ret = -EINVAL;
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goto end;
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}
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/* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding
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* up and leaking out of the specified area. */
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if (s->has_size && !QEMU_IS_ALIGNED(s->size, BDRV_SECTOR_SIZE)) {
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error_setg(errp, "Specified size is not multiple of %llu",
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BDRV_SECTOR_SIZE);
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ret = -EINVAL;
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goto end;
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}
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ret = 0;
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end:
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qemu_opts_del(opts);
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return ret;
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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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assert(reopen_state != NULL);
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assert(reopen_state->bs != NULL);
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reopen_state->opaque = g_new0(BDRVRawState, 1);
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return raw_read_options(
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reopen_state->options,
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reopen_state->bs,
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reopen_state->opaque,
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errp);
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}
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static void raw_reopen_commit(BDRVReopenState *state)
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{
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BDRVRawState *new_s = state->opaque;
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BDRVRawState *s = state->bs->opaque;
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memcpy(s, new_s, sizeof(BDRVRawState));
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g_free(state->opaque);
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state->opaque = NULL;
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}
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static void raw_reopen_abort(BDRVReopenState *state)
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{
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g_free(state->opaque);
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state->opaque = NULL;
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}
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/* Check and adjust the offset, against 'offset' and 'size' options. */
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static inline int raw_adjust_offset(BlockDriverState *bs, uint64_t *offset,
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uint64_t bytes, bool is_write)
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{
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BDRVRawState *s = bs->opaque;
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if (s->has_size && (*offset > s->size || bytes > (s->size - *offset))) {
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/* There's not enough space for the write, or the read request is
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* out-of-range. Don't read/write anything to prevent leaking out of
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* the size specified in options. */
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return is_write ? -ENOSPC : -EINVAL;
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}
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if (*offset > INT64_MAX - s->offset) {
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return -EINVAL;
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}
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*offset += s->offset;
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return 0;
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}
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static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
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uint64_t bytes, QEMUIOVector *qiov,
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int flags)
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{
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int ret;
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ret = raw_adjust_offset(bs, &offset, bytes, false);
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if (ret) {
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return ret;
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}
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BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
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return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
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}
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static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
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uint64_t bytes, QEMUIOVector *qiov,
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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 && offset < BLOCK_PROBE_BUF_SIZE && bytes) {
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/* Handling partial writes would be a pain - so we just
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* require that guests have 512-byte request alignment if
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* probing occurred */
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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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assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE);
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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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ret = raw_adjust_offset(bs, &offset, bytes, true);
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if (ret) {
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goto fail;
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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, offset, bytes, 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 int coroutine_fn raw_co_block_status(BlockDriverState *bs,
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bool want_zero, int64_t offset,
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int64_t bytes, int64_t *pnum,
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int64_t *map,
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BlockDriverState **file)
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{
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BDRVRawState *s = bs->opaque;
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*pnum = bytes;
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*file = bs->file->bs;
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*map = offset + s->offset;
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return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
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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 bytes,
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BdrvRequestFlags flags)
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{
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int ret;
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ret = raw_adjust_offset(bs, (uint64_t *)&offset, bytes, true);
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if (ret) {
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return ret;
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}
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return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
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}
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static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
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int64_t offset, int bytes)
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{
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int ret;
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ret = raw_adjust_offset(bs, (uint64_t *)&offset, bytes, true);
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if (ret) {
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return ret;
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}
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return bdrv_co_pdiscard(bs->file, offset, bytes);
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}
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static int64_t raw_getlength(BlockDriverState *bs)
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{
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int64_t len;
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BDRVRawState *s = bs->opaque;
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/* Update size. It should not change unless the file was externally
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* modified. */
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len = bdrv_getlength(bs->file->bs);
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if (len < 0) {
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return len;
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}
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if (len < s->offset) {
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s->size = 0;
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} else {
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if (s->has_size) {
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/* Try to honour the size */
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s->size = MIN(s->size, len - s->offset);
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} else {
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s->size = len - s->offset;
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}
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}
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return s->size;
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}
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static BlockMeasureInfo *raw_measure(QemuOpts *opts, BlockDriverState *in_bs,
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Error **errp)
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{
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BlockMeasureInfo *info;
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int64_t required;
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if (in_bs) {
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required = bdrv_getlength(in_bs);
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if (required < 0) {
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error_setg_errno(errp, -required, "Unable to get image size");
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return NULL;
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}
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} else {
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required = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
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BDRV_SECTOR_SIZE);
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}
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info = g_new(BlockMeasureInfo, 1);
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info->required = required;
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/* Unallocated sectors count towards the file size in raw images */
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info->fully_allocated = info->required;
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return info;
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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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if (bs->probed) {
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/* To make it easier to protect the first sector, any probed
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* image is restricted to read-modify-write on sub-sector
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* operations. */
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bs->bl.request_alignment = BDRV_SECTOR_SIZE;
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}
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}
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static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
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PreallocMode prealloc, Error **errp)
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{
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BDRVRawState *s = bs->opaque;
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if (s->has_size) {
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error_setg(errp, "Cannot resize fixed-size raw disks");
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return -ENOTSUP;
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}
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if (INT64_MAX - offset < s->offset) {
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error_setg(errp, "Disk size too large for the chosen offset");
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return -EINVAL;
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}
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s->size = offset;
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offset += s->offset;
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return bdrv_co_truncate(bs->file, offset, prealloc, errp);
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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 int raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
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{
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BDRVRawState *s = bs->opaque;
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if (s->offset || s->has_size) {
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return -ENOTSUP;
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}
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return bdrv_co_ioctl(bs->file->bs, req, buf);
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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_has_zero_init_truncate(BlockDriverState *bs)
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{
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return bdrv_has_zero_init_truncate(bs->file->bs);
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}
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static int coroutine_fn raw_co_create_opts(const char *filename, QemuOpts *opts,
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Error **errp)
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{
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return bdrv_create_file(filename, opts, errp);
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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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BDRVRawState *s = bs->opaque;
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int ret;
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bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
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false, errp);
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if (!bs->file) {
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return -EINVAL;
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}
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bs->sg = bs->file->bs->sg;
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bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
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(BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
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bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
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((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
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bs->file->bs->supported_zero_flags);
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if (bs->probed && !bdrv_is_read_only(bs)) {
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bdrv_refresh_filename(bs->file->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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ret = raw_read_options(options, bs, s, errp);
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if (ret < 0) {
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return ret;
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}
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if (bs->sg && (s->offset || s->has_size)) {
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error_setg(errp, "Cannot use offset/size with SCSI generic devices");
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return -EINVAL;
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}
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return 0;
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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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BDRVRawState *s = bs->opaque;
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int ret;
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ret = bdrv_probe_blocksizes(bs->file->bs, bsz);
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if (ret < 0) {
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return ret;
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}
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if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) {
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return -ENOTSUP;
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}
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return 0;
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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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BDRVRawState *s = bs->opaque;
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if (s->offset || s->has_size) {
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return -ENOTSUP;
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}
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return bdrv_probe_geometry(bs->file->bs, geo);
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}
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static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
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BdrvChild *src,
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uint64_t src_offset,
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BdrvChild *dst,
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uint64_t dst_offset,
|
|
uint64_t bytes,
|
|
BdrvRequestFlags read_flags,
|
|
BdrvRequestFlags write_flags)
|
|
{
|
|
int ret;
|
|
|
|
ret = raw_adjust_offset(bs, &src_offset, bytes, false);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
|
|
bytes, read_flags, write_flags);
|
|
}
|
|
|
|
static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
|
|
BdrvChild *src,
|
|
uint64_t src_offset,
|
|
BdrvChild *dst,
|
|
uint64_t dst_offset,
|
|
uint64_t bytes,
|
|
BdrvRequestFlags read_flags,
|
|
BdrvRequestFlags write_flags)
|
|
{
|
|
int ret;
|
|
|
|
ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
return bdrv_co_copy_range_to(src, src_offset, bs->file, dst_offset, bytes,
|
|
read_flags, write_flags);
|
|
}
|
|
|
|
static const char *const raw_strong_runtime_opts[] = {
|
|
"offset",
|
|
"size",
|
|
|
|
NULL
|
|
};
|
|
|
|
BlockDriver bdrv_raw = {
|
|
.format_name = "raw",
|
|
.instance_size = sizeof(BDRVRawState),
|
|
.bdrv_probe = &raw_probe,
|
|
.bdrv_reopen_prepare = &raw_reopen_prepare,
|
|
.bdrv_reopen_commit = &raw_reopen_commit,
|
|
.bdrv_reopen_abort = &raw_reopen_abort,
|
|
.bdrv_open = &raw_open,
|
|
.bdrv_child_perm = bdrv_filter_default_perms,
|
|
.bdrv_co_create_opts = &raw_co_create_opts,
|
|
.bdrv_co_preadv = &raw_co_preadv,
|
|
.bdrv_co_pwritev = &raw_co_pwritev,
|
|
.bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
|
|
.bdrv_co_pdiscard = &raw_co_pdiscard,
|
|
.bdrv_co_block_status = &raw_co_block_status,
|
|
.bdrv_co_copy_range_from = &raw_co_copy_range_from,
|
|
.bdrv_co_copy_range_to = &raw_co_copy_range_to,
|
|
.bdrv_co_truncate = &raw_co_truncate,
|
|
.bdrv_getlength = &raw_getlength,
|
|
.has_variable_length = true,
|
|
.bdrv_measure = &raw_measure,
|
|
.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_eject = &raw_eject,
|
|
.bdrv_lock_medium = &raw_lock_medium,
|
|
.bdrv_co_ioctl = &raw_co_ioctl,
|
|
.create_opts = &raw_create_opts,
|
|
.bdrv_has_zero_init = &raw_has_zero_init,
|
|
.bdrv_has_zero_init_truncate = &raw_has_zero_init_truncate,
|
|
.strong_runtime_opts = raw_strong_runtime_opts,
|
|
.mutable_opts = mutable_opts,
|
|
};
|
|
|
|
static void bdrv_raw_init(void)
|
|
{
|
|
bdrv_register(&bdrv_raw);
|
|
}
|
|
|
|
block_init(bdrv_raw_init);
|