1 /* BlockDriver implementation for "raw" format driver
3 * Copyright (C) 2010-2016 Red Hat, Inc.
4 * Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com>
5 * Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com>
8 * Laszlo Ersek <lersek@redhat.com>
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to
12 * deal in the Software without restriction, including without limitation the
13 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
14 * sell copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 #include "qemu/osdep.h"
30 #include "block/block-io.h"
31 #include "block/block_int.h"
32 #include "qapi/error.h"
33 #include "qemu/module.h"
34 #include "qemu/option.h"
35 #include "qemu/memalign.h"
37 typedef struct BDRVRawState {
43 static const char *const mutable_opts[] = { "offset", "size", NULL };
45 static QemuOptsList raw_runtime_opts = {
47 .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
51 .type = QEMU_OPT_SIZE,
52 .help = "offset in the disk where the image starts",
56 .type = QEMU_OPT_SIZE,
57 .help = "virtual disk size",
63 static QemuOptsList raw_create_opts = {
64 .name = "raw-create-opts",
65 .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
68 .name = BLOCK_OPT_SIZE,
69 .type = QEMU_OPT_SIZE,
70 .help = "Virtual disk size"
76 static int raw_read_options(QDict *options, uint64_t *offset, bool *has_size,
77 uint64_t *size, Error **errp)
79 QemuOpts *opts = NULL;
82 opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
83 if (!qemu_opts_absorb_qdict(opts, options, errp)) {
88 *offset = qemu_opt_get_size(opts, "offset", 0);
89 *has_size = qemu_opt_find(opts, "size");
90 *size = qemu_opt_get_size(opts, "size", 0);
98 static int raw_apply_options(BlockDriverState *bs, BDRVRawState *s,
99 uint64_t offset, bool has_size, uint64_t size,
102 int64_t real_size = 0;
104 real_size = bdrv_getlength(bs->file->bs);
106 error_setg_errno(errp, -real_size, "Could not get image size");
110 /* Check size and offset */
111 if (offset > real_size) {
112 error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than "
113 "size of the containing file (%" PRId64 ")",
114 s->offset, real_size);
118 if (has_size && (real_size - offset) < size) {
119 error_setg(errp, "The sum of offset (%" PRIu64 ") and size "
120 "(%" PRIu64 ") has to be smaller or equal to the "
121 " actual size of the containing file (%" PRId64 ")",
122 s->offset, s->size, real_size);
126 /* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding
127 * up and leaking out of the specified area. */
128 if (has_size && !QEMU_IS_ALIGNED(size, BDRV_SECTOR_SIZE)) {
129 error_setg(errp, "Specified size is not multiple of %llu",
135 s->has_size = has_size;
136 s->size = has_size ? size : real_size - offset;
141 static int raw_reopen_prepare(BDRVReopenState *reopen_state,
142 BlockReopenQueue *queue, Error **errp)
145 uint64_t offset, size;
148 assert(reopen_state != NULL);
149 assert(reopen_state->bs != NULL);
151 reopen_state->opaque = g_new0(BDRVRawState, 1);
153 ret = raw_read_options(reopen_state->options, &offset, &has_size, &size,
159 ret = raw_apply_options(reopen_state->bs, reopen_state->opaque,
160 offset, has_size, size, errp);
168 static void raw_reopen_commit(BDRVReopenState *state)
170 BDRVRawState *new_s = state->opaque;
171 BDRVRawState *s = state->bs->opaque;
173 memcpy(s, new_s, sizeof(BDRVRawState));
175 g_free(state->opaque);
176 state->opaque = NULL;
179 static void raw_reopen_abort(BDRVReopenState *state)
181 g_free(state->opaque);
182 state->opaque = NULL;
185 /* Check and adjust the offset, against 'offset' and 'size' options. */
186 static inline int raw_adjust_offset(BlockDriverState *bs, int64_t *offset,
187 int64_t bytes, bool is_write)
189 BDRVRawState *s = bs->opaque;
191 if (s->has_size && (*offset > s->size || bytes > (s->size - *offset))) {
192 /* There's not enough space for the write, or the read request is
193 * out-of-range. Don't read/write anything to prevent leaking out of
194 * the size specified in options. */
195 return is_write ? -ENOSPC : -EINVAL;
198 if (*offset > INT64_MAX - s->offset) {
201 *offset += s->offset;
206 static int coroutine_fn GRAPH_RDLOCK
207 raw_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
208 QEMUIOVector *qiov, BdrvRequestFlags flags)
212 ret = raw_adjust_offset(bs, &offset, bytes, false);
217 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO);
218 return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
221 static int coroutine_fn GRAPH_RDLOCK
222 raw_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
223 QEMUIOVector *qiov, BdrvRequestFlags flags)
227 QEMUIOVector local_qiov;
230 if (bs->probed && offset < BLOCK_PROBE_BUF_SIZE && bytes) {
231 /* Handling partial writes would be a pain - so we just
232 * require that guests have 512-byte request alignment if
233 * probing occurred */
234 QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
235 QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
236 assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE);
238 buf = qemu_try_blockalign(bs->file->bs, 512);
244 ret = qemu_iovec_to_buf(qiov, 0, buf, 512);
250 drv = bdrv_probe_all(buf, 512, NULL);
251 if (drv != bs->drv) {
256 /* Use the checked buffer, a malicious guest might be overwriting its
257 * original buffer in the background. */
258 qemu_iovec_init(&local_qiov, qiov->niov + 1);
259 qemu_iovec_add(&local_qiov, buf, 512);
260 qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512);
263 flags &= ~BDRV_REQ_REGISTERED_BUF;
266 ret = raw_adjust_offset(bs, &offset, bytes, true);
271 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO);
272 ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
275 if (qiov == &local_qiov) {
276 qemu_iovec_destroy(&local_qiov);
282 static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
283 bool want_zero, int64_t offset,
284 int64_t bytes, int64_t *pnum,
286 BlockDriverState **file)
288 BDRVRawState *s = bs->opaque;
290 *file = bs->file->bs;
291 *map = offset + s->offset;
292 return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
295 static int coroutine_fn GRAPH_RDLOCK
296 raw_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
297 BdrvRequestFlags flags)
301 ret = raw_adjust_offset(bs, &offset, bytes, true);
305 return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
308 static int coroutine_fn GRAPH_RDLOCK
309 raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
313 ret = raw_adjust_offset(bs, &offset, bytes, true);
317 return bdrv_co_pdiscard(bs->file, offset, bytes);
320 static int coroutine_fn GRAPH_RDLOCK
321 raw_co_zone_report(BlockDriverState *bs, int64_t offset,
322 unsigned int *nr_zones,
323 BlockZoneDescriptor *zones)
325 return bdrv_co_zone_report(bs->file->bs, offset, nr_zones, zones);
328 static int coroutine_fn GRAPH_RDLOCK
329 raw_co_zone_mgmt(BlockDriverState *bs, BlockZoneOp op,
330 int64_t offset, int64_t len)
332 return bdrv_co_zone_mgmt(bs->file->bs, op, offset, len);
335 static int coroutine_fn GRAPH_RDLOCK
336 raw_co_zone_append(BlockDriverState *bs,int64_t *offset, QEMUIOVector *qiov,
337 BdrvRequestFlags flags)
339 return bdrv_co_zone_append(bs->file->bs, offset, qiov, flags);
342 static int64_t coroutine_fn GRAPH_RDLOCK
343 raw_co_getlength(BlockDriverState *bs)
346 BDRVRawState *s = bs->opaque;
348 /* Update size. It should not change unless the file was externally
350 len = bdrv_co_getlength(bs->file->bs);
355 if (len < s->offset) {
359 /* Try to honour the size */
360 s->size = MIN(s->size, len - s->offset);
362 s->size = len - s->offset;
369 static BlockMeasureInfo *raw_measure(QemuOpts *opts, BlockDriverState *in_bs,
372 BlockMeasureInfo *info;
376 required = bdrv_getlength(in_bs);
378 error_setg_errno(errp, -required, "Unable to get image size");
382 required = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
386 info = g_new0(BlockMeasureInfo, 1);
387 info->required = required;
389 /* Unallocated sectors count towards the file size in raw images */
390 info->fully_allocated = info->required;
394 static int coroutine_fn GRAPH_RDLOCK
395 raw_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
397 return bdrv_co_get_info(bs->file->bs, bdi);
400 static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
402 bs->bl.has_variable_length = bs->file->bs->bl.has_variable_length;
405 /* To make it easier to protect the first sector, any probed
406 * image is restricted to read-modify-write on sub-sector
408 bs->bl.request_alignment = BDRV_SECTOR_SIZE;
412 static int coroutine_fn GRAPH_RDLOCK
413 raw_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
414 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp)
416 BDRVRawState *s = bs->opaque;
419 error_setg(errp, "Cannot resize fixed-size raw disks");
423 if (INT64_MAX - offset < s->offset) {
424 error_setg(errp, "Disk size too large for the chosen offset");
430 return bdrv_co_truncate(bs->file, offset, exact, prealloc, flags, errp);
433 static void coroutine_fn GRAPH_RDLOCK
434 raw_co_eject(BlockDriverState *bs, bool eject_flag)
436 bdrv_co_eject(bs->file->bs, eject_flag);
439 static void coroutine_fn GRAPH_RDLOCK
440 raw_co_lock_medium(BlockDriverState *bs, bool locked)
442 bdrv_co_lock_medium(bs->file->bs, locked);
445 static int coroutine_fn GRAPH_RDLOCK
446 raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
448 BDRVRawState *s = bs->opaque;
449 if (s->offset || s->has_size) {
452 return bdrv_co_ioctl(bs->file->bs, req, buf);
455 static int raw_has_zero_init(BlockDriverState *bs)
457 return bdrv_has_zero_init(bs->file->bs);
460 static int coroutine_fn GRAPH_UNLOCKED
461 raw_co_create_opts(BlockDriver *drv, const char *filename,
462 QemuOpts *opts, Error **errp)
464 return bdrv_co_create_file(filename, opts, errp);
467 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
470 BDRVRawState *s = bs->opaque;
473 uint64_t offset, size;
474 BdrvChildRole file_role;
477 ret = raw_read_options(options, &offset, &has_size, &size, errp);
483 * Without offset and a size limit, this driver behaves very much
484 * like a filter. With any such limit, it does not.
486 if (offset || has_size) {
487 file_role = BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY;
489 file_role = BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY;
492 bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
493 file_role, false, errp);
498 bs->sg = bdrv_is_sg(bs->file->bs);
499 bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
500 (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
501 bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
502 ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
503 bs->file->bs->supported_zero_flags);
504 bs->supported_truncate_flags = bs->file->bs->supported_truncate_flags &
507 if (bs->probed && !bdrv_is_read_only(bs)) {
508 bdrv_graph_rdlock_main_loop();
509 bdrv_refresh_filename(bs->file->bs);
510 bdrv_graph_rdunlock_main_loop();
512 "WARNING: Image format was not specified for '%s' and probing "
514 " Automatically detecting the format is dangerous for "
515 "raw images, write operations on block 0 will be restricted.\n"
516 " Specify the 'raw' format explicitly to remove the "
518 bs->file->bs->filename);
521 ctx = bdrv_get_aio_context(bs);
522 aio_context_acquire(ctx);
523 ret = raw_apply_options(bs, s, offset, has_size, size, errp);
524 aio_context_release(ctx);
530 if (bdrv_is_sg(bs) && (s->offset || s->has_size)) {
531 error_setg(errp, "Cannot use offset/size with SCSI generic devices");
538 static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
540 /* smallest possible positive score so that raw is used if and only if no
541 * other block driver works
546 static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
548 BDRVRawState *s = bs->opaque;
551 ret = bdrv_probe_blocksizes(bs->file->bs, bsz);
556 if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) {
563 static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
565 BDRVRawState *s = bs->opaque;
566 if (s->offset || s->has_size) {
569 return bdrv_probe_geometry(bs->file->bs, geo);
572 static int coroutine_fn GRAPH_RDLOCK
573 raw_co_copy_range_from(BlockDriverState *bs,
574 BdrvChild *src, int64_t src_offset,
575 BdrvChild *dst, int64_t dst_offset,
576 int64_t bytes, BdrvRequestFlags read_flags,
577 BdrvRequestFlags write_flags)
581 ret = raw_adjust_offset(bs, &src_offset, bytes, false);
585 return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
586 bytes, read_flags, write_flags);
589 static int coroutine_fn GRAPH_RDLOCK
590 raw_co_copy_range_to(BlockDriverState *bs,
591 BdrvChild *src, int64_t src_offset,
592 BdrvChild *dst, int64_t dst_offset,
593 int64_t bytes, BdrvRequestFlags read_flags,
594 BdrvRequestFlags write_flags)
598 ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
602 return bdrv_co_copy_range_to(src, src_offset, bs->file, dst_offset, bytes,
603 read_flags, write_flags);
606 static const char *const raw_strong_runtime_opts[] = {
613 static void raw_cancel_in_flight(BlockDriverState *bs)
615 bdrv_cancel_in_flight(bs->file->bs);
618 static void raw_child_perm(BlockDriverState *bs, BdrvChild *c,
620 BlockReopenQueue *reopen_queue,
621 uint64_t parent_perm, uint64_t parent_shared,
622 uint64_t *nperm, uint64_t *nshared)
624 bdrv_default_perms(bs, c, role, reopen_queue, parent_perm,
625 parent_shared, nperm, nshared);
628 * bdrv_default_perms() may add WRITE and/or RESIZE (see comment in
629 * bdrv_default_perms_for_storage() for an explanation) but we only need
630 * them if they are in parent_perm. Drop WRITE and RESIZE whenever possible
631 * to avoid permission conflicts.
633 *nperm &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
634 *nperm |= parent_perm & (BLK_PERM_WRITE | BLK_PERM_RESIZE);
637 BlockDriver bdrv_raw = {
638 .format_name = "raw",
639 .instance_size = sizeof(BDRVRawState),
640 .supports_zoned_children = true,
641 .bdrv_probe = &raw_probe,
642 .bdrv_reopen_prepare = &raw_reopen_prepare,
643 .bdrv_reopen_commit = &raw_reopen_commit,
644 .bdrv_reopen_abort = &raw_reopen_abort,
645 .bdrv_open = &raw_open,
646 .bdrv_child_perm = raw_child_perm,
647 .bdrv_co_create_opts = &raw_co_create_opts,
648 .bdrv_co_preadv = &raw_co_preadv,
649 .bdrv_co_pwritev = &raw_co_pwritev,
650 .bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
651 .bdrv_co_pdiscard = &raw_co_pdiscard,
652 .bdrv_co_zone_report = &raw_co_zone_report,
653 .bdrv_co_zone_mgmt = &raw_co_zone_mgmt,
654 .bdrv_co_zone_append = &raw_co_zone_append,
655 .bdrv_co_block_status = &raw_co_block_status,
656 .bdrv_co_copy_range_from = &raw_co_copy_range_from,
657 .bdrv_co_copy_range_to = &raw_co_copy_range_to,
658 .bdrv_co_truncate = &raw_co_truncate,
659 .bdrv_co_getlength = &raw_co_getlength,
661 .bdrv_measure = &raw_measure,
662 .bdrv_co_get_info = &raw_co_get_info,
663 .bdrv_refresh_limits = &raw_refresh_limits,
664 .bdrv_probe_blocksizes = &raw_probe_blocksizes,
665 .bdrv_probe_geometry = &raw_probe_geometry,
666 .bdrv_co_eject = &raw_co_eject,
667 .bdrv_co_lock_medium = &raw_co_lock_medium,
668 .bdrv_co_ioctl = &raw_co_ioctl,
669 .create_opts = &raw_create_opts,
670 .bdrv_has_zero_init = &raw_has_zero_init,
671 .strong_runtime_opts = raw_strong_runtime_opts,
672 .mutable_opts = mutable_opts,
673 .bdrv_cancel_in_flight = raw_cancel_in_flight,
676 static void bdrv_raw_init(void)
678 bdrv_register(&bdrv_raw);
681 block_init(bdrv_raw_init);