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_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
{
42 static const char *const mutable_opts
[] = { "offset", "size", NULL
};
44 static QemuOptsList raw_runtime_opts
= {
46 .head
= QTAILQ_HEAD_INITIALIZER(raw_runtime_opts
.head
),
50 .type
= QEMU_OPT_SIZE
,
51 .help
= "offset in the disk where the image starts",
55 .type
= QEMU_OPT_SIZE
,
56 .help
= "virtual disk size",
62 static QemuOptsList raw_create_opts
= {
63 .name
= "raw-create-opts",
64 .head
= QTAILQ_HEAD_INITIALIZER(raw_create_opts
.head
),
67 .name
= BLOCK_OPT_SIZE
,
68 .type
= QEMU_OPT_SIZE
,
69 .help
= "Virtual disk size"
75 static int raw_read_options(QDict
*options
, uint64_t *offset
, bool *has_size
,
76 uint64_t *size
, Error
**errp
)
78 QemuOpts
*opts
= NULL
;
81 opts
= qemu_opts_create(&raw_runtime_opts
, NULL
, 0, &error_abort
);
82 if (!qemu_opts_absorb_qdict(opts
, options
, errp
)) {
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);
97 static int raw_apply_options(BlockDriverState
*bs
, BDRVRawState
*s
,
98 uint64_t offset
, bool has_size
, uint64_t size
,
101 int64_t real_size
= 0;
103 real_size
= bdrv_getlength(bs
->file
->bs
);
105 error_setg_errno(errp
, -real_size
, "Could not get image 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
);
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
);
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",
134 s
->has_size
= has_size
;
135 s
->size
= has_size
? size
: real_size
- offset
;
140 static int raw_reopen_prepare(BDRVReopenState
*reopen_state
,
141 BlockReopenQueue
*queue
, Error
**errp
)
144 uint64_t offset
, size
;
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
,
158 ret
= raw_apply_options(reopen_state
->bs
, reopen_state
->opaque
,
159 offset
, has_size
, size
, errp
);
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
) {
200 *offset
+= s
->offset
;
205 static int coroutine_fn
raw_co_preadv(BlockDriverState
*bs
, int64_t offset
,
206 int64_t bytes
, QEMUIOVector
*qiov
,
207 BdrvRequestFlags flags
)
211 ret
= raw_adjust_offset(bs
, &offset
, bytes
, false);
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
)
226 QEMUIOVector local_qiov
;
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);
243 ret
= qemu_iovec_to_buf(qiov
, 0, buf
, 512);
249 drv
= bdrv_probe_all(buf
, 512, NULL
);
250 if (drv
!= bs
->drv
) {
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);
263 ret
= raw_adjust_offset(bs
, &offset
, bytes
, true);
268 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
269 ret
= bdrv_co_pwritev(bs
->file
, offset
, bytes
, qiov
, flags
);
272 if (qiov
== &local_qiov
) {
273 qemu_iovec_destroy(&local_qiov
);
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
,
283 BlockDriverState
**file
)
285 BDRVRawState
*s
= bs
->opaque
;
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
)
298 ret
= raw_adjust_offset(bs
, &offset
, bytes
, true);
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
)
310 ret
= raw_adjust_offset(bs
, &offset
, bytes
, true);
314 return bdrv_co_pdiscard(bs
->file
, offset
, bytes
);
317 static int64_t raw_getlength(BlockDriverState
*bs
)
320 BDRVRawState
*s
= bs
->opaque
;
322 /* Update size. It should not change unless the file was externally
324 len
= bdrv_getlength(bs
->file
->bs
);
329 if (len
< s
->offset
) {
333 /* Try to honour the size */
334 s
->size
= MIN(s
->size
, len
- s
->offset
);
336 s
->size
= len
- s
->offset
;
343 static BlockMeasureInfo
*raw_measure(QemuOpts
*opts
, BlockDriverState
*in_bs
,
346 BlockMeasureInfo
*info
;
350 required
= bdrv_getlength(in_bs
);
352 error_setg_errno(errp
, -required
, "Unable to get image size");
356 required
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
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
;
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
)
376 /* To make it easier to protect the first sector, any probed
377 * image is restricted to read-modify-write on sub-sector
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
;
390 error_setg(errp
, "Cannot resize fixed-size raw disks");
394 if (INT64_MAX
- offset
< s
->offset
) {
395 error_setg(errp
, "Disk size too large for the chosen 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
) {
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
,
433 return bdrv_create_file(filename
, opts
, errp
);
436 static int raw_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
439 BDRVRawState
*s
= bs
->opaque
;
441 uint64_t offset
, size
;
442 BdrvChildRole file_role
;
445 ret
= raw_read_options(options
, &offset
, &has_size
, &size
, errp
);
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
;
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
);
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
&
475 if (bs
->probed
&& !bdrv_is_read_only(bs
)) {
476 bdrv_refresh_filename(bs
->file
->bs
);
478 "WARNING: Image format was not specified for '%s' and probing "
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 "
484 bs
->file
->bs
->filename
);
487 ret
= raw_apply_options(bs
, s
, offset
, has_size
, size
, errp
);
492 if (bdrv_is_sg(bs
) && (s
->offset
|| s
->has_size
)) {
493 error_setg(errp
, "Cannot use offset/size with SCSI generic devices");
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
508 static int raw_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
510 BDRVRawState
*s
= bs
->opaque
;
513 ret
= bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
518 if (!QEMU_IS_ALIGNED(s
->offset
, MAX(bsz
->log
, bsz
->phys
))) {
525 static int raw_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
527 BDRVRawState
*s
= bs
->opaque
;
528 if (s
->offset
|| s
->has_size
) {
531 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
534 static int coroutine_fn
raw_co_copy_range_from(BlockDriverState
*bs
,
540 BdrvRequestFlags read_flags
,
541 BdrvRequestFlags write_flags
)
545 ret
= raw_adjust_offset(bs
, &src_offset
, bytes
, false);
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
,
559 BdrvRequestFlags read_flags
,
560 BdrvRequestFlags write_flags
)
564 ret
= raw_adjust_offset(bs
, &dst_offset
, bytes
, true);
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
[] = {
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
,
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
,
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
);