raw_bsd: add offset and size options
Added two new options 'offset' and 'size'. This makes it possible to use only part of the file as a device. This can be used e.g. to limit the access only to single partition in a disk image or use a disk inside a tar archive (like OVA). When 'size' is specified we do our best to honour it. Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Tomáš Golembiovský
Kevin Wolf
parent
7eb13c9daa
commit
2fdc70452a
217
block/raw_bsd.c
217
block/raw_bsd.c
@ -31,6 +31,30 @@
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#include "qapi/error.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 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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@ -44,16 +68,108 @@ static QemuOptsList raw_create_opts = {
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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 (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 || (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 (!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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return 0;
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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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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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BDRVRawState *s = bs->opaque;
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if (offset > UINT64_MAX - s->offset) {
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return -EINVAL;
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}
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offset += s->offset;
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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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@ -62,11 +178,23 @@ 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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BDRVRawState *s = bs->opaque;
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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 (s->has_size && (offset > s->size || bytes > (s->size - offset))) {
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/* There's not enough space for the data. Don't write anything and just
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* fail to prevent leaking out of the size specified in options. */
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return -ENOSPC;
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}
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if (offset > UINT64_MAX - s->offset) {
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ret = -EINVAL;
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goto fail;
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}
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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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@ -101,6 +229,8 @@ static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
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qiov = &local_qiov;
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}
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offset += s->offset;
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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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@ -117,8 +247,10 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
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int nb_sectors, int *pnum,
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BlockDriverState **file)
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{
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BDRVRawState *s = bs->opaque;
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*pnum = nb_sectors;
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*file = bs->file->bs;
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sector_num += s->offset / BDRV_SECTOR_SIZE;
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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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@ -127,18 +259,49 @@ 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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BDRVRawState *s = bs->opaque;
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if (offset > UINT64_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 bdrv_co_pwrite_zeroes(bs->file, offset, count, 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 count)
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{
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BDRVRawState *s = bs->opaque;
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if (offset > UINT64_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 bdrv_co_pdiscard(bs->file->bs, offset, count);
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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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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 int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
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@ -158,6 +321,18 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
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static int raw_truncate(BlockDriverState *bs, int64_t offset)
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{
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BDRVRawState *s = bs->opaque;
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if (s->has_size) {
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return -ENOTSUP;
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}
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if (INT64_MAX - offset < s->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_truncate(bs->file->bs, offset);
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}
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@ -178,6 +353,10 @@ static void raw_lock_medium(BlockDriverState *bs, bool locked)
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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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@ -194,6 +373,9 @@ static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
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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->sg = bs->file->bs->sg;
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bs->supported_write_flags = BDRV_REQ_FUA &
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bs->file->bs->supported_write_flags;
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@ -211,6 +393,16 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
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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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@ -228,18 +420,37 @@ static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
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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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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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BlockDriver bdrv_raw = {
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.format_name = "raw",
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.instance_size = sizeof(BDRVRawState),
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.bdrv_probe = &raw_probe,
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.bdrv_reopen_prepare = &raw_reopen_prepare,
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.bdrv_reopen_commit = &raw_reopen_commit,
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.bdrv_reopen_abort = &raw_reopen_abort,
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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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@ -2269,6 +2269,20 @@
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'*export': 'str',
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'*tls-creds': 'str' } }
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##
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# @BlockdevOptionsRaw
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#
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# Driver specific block device options for the raw driver.
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#
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# @offset: #optional position where the block device starts
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# @size: #optional the assumed size of the device
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#
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# Since: 2.8
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##
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{ 'struct': 'BlockdevOptionsRaw',
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'base': 'BlockdevOptionsGenericFormat',
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'data': { '*offset': 'int', '*size': 'int' } }
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##
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# @BlockdevOptions
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#
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@ -2323,7 +2337,7 @@
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'qcow': 'BlockdevOptionsGenericCOWFormat',
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'qed': 'BlockdevOptionsGenericCOWFormat',
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'quorum': 'BlockdevOptionsQuorum',
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'raw': 'BlockdevOptionsGenericFormat',
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'raw': 'BlockdevOptionsRaw',
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# TODO rbd: Wait for structured options
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'replication':'BlockdevOptionsReplication',
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# TODO sheepdog: Wait for structured options
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