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-rw-r--r--block/raw-format.c490
1 files changed, 490 insertions, 0 deletions
diff --git a/block/raw-format.c b/block/raw-format.c
new file mode 100644
index 0000000000..8404a82e0c
--- /dev/null
+++ b/block/raw-format.c
@@ -0,0 +1,490 @@
+/* BlockDriver implementation for "raw" format driver
+ *
+ * Copyright (C) 2010-2016 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 "qapi/error.h"
+#include "qemu/option.h"
+
+typedef struct BDRVRawState {
+ uint64_t offset;
+ uint64_t size;
+ bool has_size;
+} BDRVRawState;
+
+static QemuOptsList raw_runtime_opts = {
+ .name = "raw",
+ .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
+ .desc = {
+ {
+ .name = "offset",
+ .type = QEMU_OPT_SIZE,
+ .help = "offset in the disk where the image starts",
+ },
+ {
+ .name = "size",
+ .type = QEMU_OPT_SIZE,
+ .help = "virtual disk size",
+ },
+ { /* end of list */ }
+ },
+};
+
+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_read_options(QDict *options, BlockDriverState *bs,
+ BDRVRawState *s, Error **errp)
+{
+ Error *local_err = NULL;
+ QemuOpts *opts = NULL;
+ int64_t real_size = 0;
+ int ret;
+
+ real_size = bdrv_getlength(bs->file->bs);
+ if (real_size < 0) {
+ error_setg_errno(errp, -real_size, "Could not get image size");
+ return real_size;
+ }
+
+ opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ s->offset = qemu_opt_get_size(opts, "offset", 0);
+ if (s->offset > real_size) {
+ error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than "
+ "size of the containing file (%" PRId64 ")",
+ s->offset, real_size);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ if (qemu_opt_find(opts, "size") != NULL) {
+ s->size = qemu_opt_get_size(opts, "size", 0);
+ s->has_size = true;
+ } else {
+ s->has_size = false;
+ s->size = real_size - s->offset;
+ }
+
+ /* Check size and offset */
+ if ((real_size - s->offset) < s->size) {
+ error_setg(errp, "The sum of offset (%" PRIu64 ") and size "
+ "(%" PRIu64 ") has to be smaller or equal to the "
+ " actual size of the containing file (%" PRId64 ")",
+ s->offset, s->size, real_size);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ /* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding
+ * up and leaking out of the specified area. */
+ if (s->has_size && !QEMU_IS_ALIGNED(s->size, BDRV_SECTOR_SIZE)) {
+ error_setg(errp, "Specified size is not multiple of %llu",
+ BDRV_SECTOR_SIZE);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ ret = 0;
+
+end:
+
+ qemu_opts_del(opts);
+
+ return ret;
+}
+
+static int raw_reopen_prepare(BDRVReopenState *reopen_state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ assert(reopen_state != NULL);
+ assert(reopen_state->bs != NULL);
+
+ reopen_state->opaque = g_new0(BDRVRawState, 1);
+
+ return raw_read_options(
+ reopen_state->options,
+ reopen_state->bs,
+ reopen_state->opaque,
+ errp);
+}
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+ BDRVRawState *new_s = state->opaque;
+ BDRVRawState *s = state->bs->opaque;
+
+ memcpy(s, new_s, sizeof(BDRVRawState));
+
+ g_free(state->opaque);
+ state->opaque = NULL;
+}
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+ g_free(state->opaque);
+ state->opaque = NULL;
+}
+
+static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
+{
+ BDRVRawState *s = bs->opaque;
+
+ if (offset > UINT64_MAX - s->offset) {
+ return -EINVAL;
+ }
+ offset += s->offset;
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
+}
+
+static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov,
+ int flags)
+{
+ BDRVRawState *s = bs->opaque;
+ void *buf = NULL;
+ BlockDriver *drv;
+ QEMUIOVector local_qiov;
+ int ret;
+
+ if (s->has_size && (offset > s->size || bytes > (s->size - offset))) {
+ /* There's not enough space for the data. Don't write anything and just
+ * fail to prevent leaking out of the size specified in options. */
+ return -ENOSPC;
+ }
+
+ if (offset > UINT64_MAX - s->offset) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (bs->probed && offset < BLOCK_PROBE_BUF_SIZE && bytes) {
+ /* Handling partial writes would be a pain - so we just
+ * require that guests have 512-byte request alignment if
+ * probing occurred */
+ QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
+ QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
+ assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE);
+
+ 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;
+ }
+
+ offset += s->offset;
+
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
+
+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)
+{
+ BDRVRawState *s = bs->opaque;
+ *pnum = nb_sectors;
+ *file = bs->file->bs;
+ sector_num += s->offset / BDRV_SECTOR_SIZE;
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
+ (sector_num << BDRV_SECTOR_BITS);
+}
+
+static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
+ int64_t offset, int count,
+ BdrvRequestFlags flags)
+{
+ BDRVRawState *s = bs->opaque;
+ if (offset > UINT64_MAX - s->offset) {
+ return -EINVAL;
+ }
+ offset += s->offset;
+ return bdrv_co_pwrite_zeroes(bs->file, offset, count, flags);
+}
+
+static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
+ int64_t offset, int count)
+{
+ BDRVRawState *s = bs->opaque;
+ if (offset > UINT64_MAX - s->offset) {
+ return -EINVAL;
+ }
+ offset += s->offset;
+ return bdrv_co_pdiscard(bs->file->bs, offset, count);
+}
+
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+ int64_t len;
+ BDRVRawState *s = bs->opaque;
+
+ /* Update size. It should not change unless the file was externally
+ * modified. */
+ len = bdrv_getlength(bs->file->bs);
+ if (len < 0) {
+ return len;
+ }
+
+ if (len < s->offset) {
+ s->size = 0;
+ } else {
+ if (s->has_size) {
+ /* Try to honour the size */
+ s->size = MIN(s->size, len - s->offset);
+ } else {
+ s->size = len - s->offset;
+ }
+ }
+
+ return s->size;
+}
+
+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)
+{
+ if (bs->probed) {
+ /* To make it easier to protect the first sector, any probed
+ * image is restricted to read-modify-write on sub-sector
+ * operations. */
+ bs->bl.request_alignment = BDRV_SECTOR_SIZE;
+ }
+}
+
+static int raw_truncate(BlockDriverState *bs, int64_t offset)
+{
+ BDRVRawState *s = bs->opaque;
+
+ if (s->has_size) {
+ return -ENOTSUP;
+ }
+
+ if (INT64_MAX - offset < s->offset) {
+ return -EINVAL;
+ }
+
+ s->size = offset;
+ offset += s->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 int raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
+{
+ BDRVRawState *s = bs->opaque;
+ if (s->offset || s->has_size) {
+ return -ENOTSUP;
+ }
+ return bdrv_co_ioctl(bs->file->bs, req, buf);
+}
+
+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)
+{
+ return bdrv_create_file(filename, opts, errp);
+}
+
+static int raw_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ BDRVRawState *s = bs->opaque;
+ int ret;
+
+ bs->sg = bs->file->bs->sg;
+ bs->supported_write_flags = BDRV_REQ_FUA &
+ bs->file->bs->supported_write_flags;
+ bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+ bs->file->bs->supported_zero_flags;
+
+ 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);
+ }
+
+ ret = raw_read_options(options, bs, s, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (bs->sg && (s->offset || s->has_size)) {
+ error_setg(errp, "Cannot use offset/size with SCSI generic devices");
+ return -EINVAL;
+ }
+
+ 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)
+{
+ BDRVRawState *s = bs->opaque;
+ int ret;
+
+ ret = bdrv_probe_blocksizes(bs->file->bs, bsz);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) {
+ return -ENOTSUP;
+ }
+
+ return 0;
+}
+
+static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
+{
+ BDRVRawState *s = bs->opaque;
+ if (s->offset || s->has_size) {
+ return -ENOTSUP;
+ }
+ return bdrv_probe_geometry(bs->file->bs, geo);
+}
+
+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_close = &raw_close,
+ .bdrv_create = &raw_create,
+ .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_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_co_ioctl = &raw_co_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);
generated by cgit v1.2.3 (git 2.26.2) at 2025-01-10 21:15:52 +0000