vhost-user-blk: make 'config_wce' part of 'host_features'
[qemu.git] / block / raw-format.c
blobc7278e348ea5990af858e53284d0f6b17c1b0a55
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>
7 * Author:
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
26 * IN THE SOFTWARE.
29 #include "qemu/osdep.h"
30 #include "block/block_int.h"
31 #include "qapi/error.h"
32 #include "qemu/module.h"
33 #include "qemu/option.h"
34 #include "qemu/memalign.h"
36 typedef struct BDRVRawState {
37 uint64_t offset;
38 uint64_t size;
39 bool has_size;
40 } BDRVRawState;
42 static const char *const mutable_opts[] = { "offset", "size", NULL };
44 static QemuOptsList raw_runtime_opts = {
45 .name = "raw",
46 .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
47 .desc = {
49 .name = "offset",
50 .type = QEMU_OPT_SIZE,
51 .help = "offset in the disk where the image starts",
54 .name = "size",
55 .type = QEMU_OPT_SIZE,
56 .help = "virtual disk size",
58 { /* end of list */ }
62 static QemuOptsList raw_create_opts = {
63 .name = "raw-create-opts",
64 .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
65 .desc = {
67 .name = BLOCK_OPT_SIZE,
68 .type = QEMU_OPT_SIZE,
69 .help = "Virtual disk size"
71 { /* end of list */ }
75 static int raw_read_options(QDict *options, uint64_t *offset, bool *has_size,
76 uint64_t *size, Error **errp)
78 QemuOpts *opts = NULL;
79 int ret;
81 opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
82 if (!qemu_opts_absorb_qdict(opts, options, errp)) {
83 ret = -EINVAL;
84 goto end;
87 *offset = qemu_opt_get_size(opts, "offset", 0);
88 *has_size = qemu_opt_find(opts, "size");
89 *size = qemu_opt_get_size(opts, "size", 0);
91 ret = 0;
92 end:
93 qemu_opts_del(opts);
94 return ret;
97 static int raw_apply_options(BlockDriverState *bs, BDRVRawState *s,
98 uint64_t offset, bool has_size, uint64_t size,
99 Error **errp)
101 int64_t real_size = 0;
103 real_size = bdrv_getlength(bs->file->bs);
104 if (real_size < 0) {
105 error_setg_errno(errp, -real_size, "Could not get image size");
106 return real_size;
109 /* Check size and offset */
110 if (offset > real_size) {
111 error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than "
112 "size of the containing file (%" PRId64 ")",
113 s->offset, real_size);
114 return -EINVAL;
117 if (has_size && (real_size - offset) < size) {
118 error_setg(errp, "The sum of offset (%" PRIu64 ") and size "
119 "(%" PRIu64 ") has to be smaller or equal to the "
120 " actual size of the containing file (%" PRId64 ")",
121 s->offset, s->size, real_size);
122 return -EINVAL;
125 /* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding
126 * up and leaking out of the specified area. */
127 if (has_size && !QEMU_IS_ALIGNED(size, BDRV_SECTOR_SIZE)) {
128 error_setg(errp, "Specified size is not multiple of %llu",
129 BDRV_SECTOR_SIZE);
130 return -EINVAL;
133 s->offset = offset;
134 s->has_size = has_size;
135 s->size = has_size ? size : real_size - offset;
137 return 0;
140 static int raw_reopen_prepare(BDRVReopenState *reopen_state,
141 BlockReopenQueue *queue, Error **errp)
143 bool has_size;
144 uint64_t offset, size;
145 int ret;
147 assert(reopen_state != NULL);
148 assert(reopen_state->bs != NULL);
150 reopen_state->opaque = g_new0(BDRVRawState, 1);
152 ret = raw_read_options(reopen_state->options, &offset, &has_size, &size,
153 errp);
154 if (ret < 0) {
155 return ret;
158 ret = raw_apply_options(reopen_state->bs, reopen_state->opaque,
159 offset, has_size, size, errp);
160 if (ret < 0) {
161 return ret;
164 return 0;
167 static void raw_reopen_commit(BDRVReopenState *state)
169 BDRVRawState *new_s = state->opaque;
170 BDRVRawState *s = state->bs->opaque;
172 memcpy(s, new_s, sizeof(BDRVRawState));
174 g_free(state->opaque);
175 state->opaque = NULL;
178 static void raw_reopen_abort(BDRVReopenState *state)
180 g_free(state->opaque);
181 state->opaque = NULL;
184 /* Check and adjust the offset, against 'offset' and 'size' options. */
185 static inline int raw_adjust_offset(BlockDriverState *bs, int64_t *offset,
186 int64_t bytes, bool is_write)
188 BDRVRawState *s = bs->opaque;
190 if (s->has_size && (*offset > s->size || bytes > (s->size - *offset))) {
191 /* There's not enough space for the write, or the read request is
192 * out-of-range. Don't read/write anything to prevent leaking out of
193 * the size specified in options. */
194 return is_write ? -ENOSPC : -EINVAL;
197 if (*offset > INT64_MAX - s->offset) {
198 return -EINVAL;
200 *offset += s->offset;
202 return 0;
205 static int coroutine_fn raw_co_preadv(BlockDriverState *bs, int64_t offset,
206 int64_t bytes, QEMUIOVector *qiov,
207 BdrvRequestFlags flags)
209 int ret;
211 ret = raw_adjust_offset(bs, &offset, bytes, false);
212 if (ret) {
213 return ret;
216 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
217 return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
220 static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, int64_t offset,
221 int64_t bytes, QEMUIOVector *qiov,
222 BdrvRequestFlags flags)
224 void *buf = NULL;
225 BlockDriver *drv;
226 QEMUIOVector local_qiov;
227 int ret;
229 if (bs->probed && offset < BLOCK_PROBE_BUF_SIZE && bytes) {
230 /* Handling partial writes would be a pain - so we just
231 * require that guests have 512-byte request alignment if
232 * probing occurred */
233 QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
234 QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
235 assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE);
237 buf = qemu_try_blockalign(bs->file->bs, 512);
238 if (!buf) {
239 ret = -ENOMEM;
240 goto fail;
243 ret = qemu_iovec_to_buf(qiov, 0, buf, 512);
244 if (ret != 512) {
245 ret = -EINVAL;
246 goto fail;
249 drv = bdrv_probe_all(buf, 512, NULL);
250 if (drv != bs->drv) {
251 ret = -EPERM;
252 goto fail;
255 /* Use the checked buffer, a malicious guest might be overwriting its
256 * original buffer in the background. */
257 qemu_iovec_init(&local_qiov, qiov->niov + 1);
258 qemu_iovec_add(&local_qiov, buf, 512);
259 qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512);
260 qiov = &local_qiov;
263 ret = raw_adjust_offset(bs, &offset, bytes, true);
264 if (ret) {
265 goto fail;
268 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
269 ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
271 fail:
272 if (qiov == &local_qiov) {
273 qemu_iovec_destroy(&local_qiov);
275 qemu_vfree(buf);
276 return ret;
279 static int coroutine_fn raw_co_block_status(BlockDriverState *bs,
280 bool want_zero, int64_t offset,
281 int64_t bytes, int64_t *pnum,
282 int64_t *map,
283 BlockDriverState **file)
285 BDRVRawState *s = bs->opaque;
286 *pnum = bytes;
287 *file = bs->file->bs;
288 *map = offset + s->offset;
289 return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
292 static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
293 int64_t offset, int64_t bytes,
294 BdrvRequestFlags flags)
296 int ret;
298 ret = raw_adjust_offset(bs, &offset, bytes, true);
299 if (ret) {
300 return ret;
302 return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
305 static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
306 int64_t offset, int64_t bytes)
308 int ret;
310 ret = raw_adjust_offset(bs, &offset, bytes, true);
311 if (ret) {
312 return ret;
314 return bdrv_co_pdiscard(bs->file, offset, bytes);
317 static int64_t raw_getlength(BlockDriverState *bs)
319 int64_t len;
320 BDRVRawState *s = bs->opaque;
322 /* Update size. It should not change unless the file was externally
323 * modified. */
324 len = bdrv_getlength(bs->file->bs);
325 if (len < 0) {
326 return len;
329 if (len < s->offset) {
330 s->size = 0;
331 } else {
332 if (s->has_size) {
333 /* Try to honour the size */
334 s->size = MIN(s->size, len - s->offset);
335 } else {
336 s->size = len - s->offset;
340 return s->size;
343 static BlockMeasureInfo *raw_measure(QemuOpts *opts, BlockDriverState *in_bs,
344 Error **errp)
346 BlockMeasureInfo *info;
347 int64_t required;
349 if (in_bs) {
350 required = bdrv_getlength(in_bs);
351 if (required < 0) {
352 error_setg_errno(errp, -required, "Unable to get image size");
353 return NULL;
355 } else {
356 required = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
357 BDRV_SECTOR_SIZE);
360 info = g_new0(BlockMeasureInfo, 1);
361 info->required = required;
363 /* Unallocated sectors count towards the file size in raw images */
364 info->fully_allocated = info->required;
365 return info;
368 static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
370 return bdrv_get_info(bs->file->bs, bdi);
373 static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
375 if (bs->probed) {
376 /* To make it easier to protect the first sector, any probed
377 * image is restricted to read-modify-write on sub-sector
378 * operations. */
379 bs->bl.request_alignment = BDRV_SECTOR_SIZE;
383 static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
384 bool exact, PreallocMode prealloc,
385 BdrvRequestFlags flags, Error **errp)
387 BDRVRawState *s = bs->opaque;
389 if (s->has_size) {
390 error_setg(errp, "Cannot resize fixed-size raw disks");
391 return -ENOTSUP;
394 if (INT64_MAX - offset < s->offset) {
395 error_setg(errp, "Disk size too large for the chosen offset");
396 return -EINVAL;
399 s->size = offset;
400 offset += s->offset;
401 return bdrv_co_truncate(bs->file, offset, exact, prealloc, flags, errp);
404 static void raw_eject(BlockDriverState *bs, bool eject_flag)
406 bdrv_eject(bs->file->bs, eject_flag);
409 static void raw_lock_medium(BlockDriverState *bs, bool locked)
411 bdrv_lock_medium(bs->file->bs, locked);
414 static int raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
416 BDRVRawState *s = bs->opaque;
417 if (s->offset || s->has_size) {
418 return -ENOTSUP;
420 return bdrv_co_ioctl(bs->file->bs, req, buf);
423 static int raw_has_zero_init(BlockDriverState *bs)
425 return bdrv_has_zero_init(bs->file->bs);
428 static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
429 const char *filename,
430 QemuOpts *opts,
431 Error **errp)
433 return bdrv_create_file(filename, opts, errp);
436 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
437 Error **errp)
439 BDRVRawState *s = bs->opaque;
440 bool has_size;
441 uint64_t offset, size;
442 BdrvChildRole file_role;
443 int ret;
445 ret = raw_read_options(options, &offset, &has_size, &size, errp);
446 if (ret < 0) {
447 return ret;
451 * Without offset and a size limit, this driver behaves very much
452 * like a filter. With any such limit, it does not.
454 if (offset || has_size) {
455 file_role = BDRV_CHILD_DATA | BDRV_CHILD_PRIMARY;
456 } else {
457 file_role = BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY;
460 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
461 file_role, false, errp);
462 if (!bs->file) {
463 return -EINVAL;
466 bs->sg = bdrv_is_sg(bs->file->bs);
467 bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
468 (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
469 bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
470 ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
471 bs->file->bs->supported_zero_flags);
472 bs->supported_truncate_flags = bs->file->bs->supported_truncate_flags &
473 BDRV_REQ_ZERO_WRITE;
475 if (bs->probed && !bdrv_is_read_only(bs)) {
476 bdrv_refresh_filename(bs->file->bs);
477 fprintf(stderr,
478 "WARNING: Image format was not specified for '%s' and probing "
479 "guessed raw.\n"
480 " Automatically detecting the format is dangerous for "
481 "raw images, write operations on block 0 will be restricted.\n"
482 " Specify the 'raw' format explicitly to remove the "
483 "restrictions.\n",
484 bs->file->bs->filename);
487 ret = raw_apply_options(bs, s, offset, has_size, size, errp);
488 if (ret < 0) {
489 return ret;
492 if (bdrv_is_sg(bs) && (s->offset || s->has_size)) {
493 error_setg(errp, "Cannot use offset/size with SCSI generic devices");
494 return -EINVAL;
497 return 0;
500 static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
502 /* smallest possible positive score so that raw is used if and only if no
503 * other block driver works
505 return 1;
508 static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
510 BDRVRawState *s = bs->opaque;
511 int ret;
513 ret = bdrv_probe_blocksizes(bs->file->bs, bsz);
514 if (ret < 0) {
515 return ret;
518 if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) {
519 return -ENOTSUP;
522 return 0;
525 static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
527 BDRVRawState *s = bs->opaque;
528 if (s->offset || s->has_size) {
529 return -ENOTSUP;
531 return bdrv_probe_geometry(bs->file->bs, geo);
534 static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
535 BdrvChild *src,
536 int64_t src_offset,
537 BdrvChild *dst,
538 int64_t dst_offset,
539 int64_t bytes,
540 BdrvRequestFlags read_flags,
541 BdrvRequestFlags write_flags)
543 int ret;
545 ret = raw_adjust_offset(bs, &src_offset, bytes, false);
546 if (ret) {
547 return ret;
549 return bdrv_co_copy_range_from(bs->file, src_offset, dst, dst_offset,
550 bytes, read_flags, write_flags);
553 static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
554 BdrvChild *src,
555 int64_t src_offset,
556 BdrvChild *dst,
557 int64_t dst_offset,
558 int64_t bytes,
559 BdrvRequestFlags read_flags,
560 BdrvRequestFlags write_flags)
562 int ret;
564 ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
565 if (ret) {
566 return ret;
568 return bdrv_co_copy_range_to(src, src_offset, bs->file, dst_offset, bytes,
569 read_flags, write_flags);
572 static const char *const raw_strong_runtime_opts[] = {
573 "offset",
574 "size",
576 NULL
579 static void raw_cancel_in_flight(BlockDriverState *bs)
581 bdrv_cancel_in_flight(bs->file->bs);
584 static void raw_child_perm(BlockDriverState *bs, BdrvChild *c,
585 BdrvChildRole role,
586 BlockReopenQueue *reopen_queue,
587 uint64_t parent_perm, uint64_t parent_shared,
588 uint64_t *nperm, uint64_t *nshared)
590 bdrv_default_perms(bs, c, role, reopen_queue, parent_perm,
591 parent_shared, nperm, nshared);
594 * bdrv_default_perms() may add WRITE and/or RESIZE (see comment in
595 * bdrv_default_perms_for_storage() for an explanation) but we only need
596 * them if they are in parent_perm. Drop WRITE and RESIZE whenever possible
597 * to avoid permission conflicts.
599 *nperm &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
600 *nperm |= parent_perm & (BLK_PERM_WRITE | BLK_PERM_RESIZE);
603 BlockDriver bdrv_raw = {
604 .format_name = "raw",
605 .instance_size = sizeof(BDRVRawState),
606 .bdrv_probe = &raw_probe,
607 .bdrv_reopen_prepare = &raw_reopen_prepare,
608 .bdrv_reopen_commit = &raw_reopen_commit,
609 .bdrv_reopen_abort = &raw_reopen_abort,
610 .bdrv_open = &raw_open,
611 .bdrv_child_perm = raw_child_perm,
612 .bdrv_co_create_opts = &raw_co_create_opts,
613 .bdrv_co_preadv = &raw_co_preadv,
614 .bdrv_co_pwritev = &raw_co_pwritev,
615 .bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
616 .bdrv_co_pdiscard = &raw_co_pdiscard,
617 .bdrv_co_block_status = &raw_co_block_status,
618 .bdrv_co_copy_range_from = &raw_co_copy_range_from,
619 .bdrv_co_copy_range_to = &raw_co_copy_range_to,
620 .bdrv_co_truncate = &raw_co_truncate,
621 .bdrv_getlength = &raw_getlength,
622 .is_format = true,
623 .has_variable_length = true,
624 .bdrv_measure = &raw_measure,
625 .bdrv_get_info = &raw_get_info,
626 .bdrv_refresh_limits = &raw_refresh_limits,
627 .bdrv_probe_blocksizes = &raw_probe_blocksizes,
628 .bdrv_probe_geometry = &raw_probe_geometry,
629 .bdrv_eject = &raw_eject,
630 .bdrv_lock_medium = &raw_lock_medium,
631 .bdrv_co_ioctl = &raw_co_ioctl,
632 .create_opts = &raw_create_opts,
633 .bdrv_has_zero_init = &raw_has_zero_init,
634 .strong_runtime_opts = raw_strong_runtime_opts,
635 .mutable_opts = mutable_opts,
636 .bdrv_cancel_in_flight = raw_cancel_in_flight,
639 static void bdrv_raw_init(void)
641 bdrv_register(&bdrv_raw);
644 block_init(bdrv_raw_init);