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
raw_co_preadv(BlockDriverState
*bs
, int64_t offset
,
207 int64_t bytes
, QEMUIOVector
*qiov
,
208 BdrvRequestFlags flags
)
212 ret
= raw_adjust_offset(bs
, &offset
, bytes
, false);
217 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
218 return bdrv_co_preadv(bs
->file
, offset
, bytes
, qiov
, flags
);
221 static int coroutine_fn
raw_co_pwritev(BlockDriverState
*bs
, int64_t offset
,
222 int64_t bytes
, QEMUIOVector
*qiov
,
223 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_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
raw_co_pwrite_zeroes(BlockDriverState
*bs
,
296 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
raw_co_pdiscard(BlockDriverState
*bs
,
309 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 int64_t coroutine_fn
raw_co_getlength(BlockDriverState
*bs
)
323 BDRVRawState
*s
= bs
->opaque
;
325 /* Update size. It should not change unless the file was externally
327 len
= bdrv_co_getlength(bs
->file
->bs
);
332 if (len
< s
->offset
) {
336 /* Try to honour the size */
337 s
->size
= MIN(s
->size
, len
- s
->offset
);
339 s
->size
= len
- s
->offset
;
346 static BlockMeasureInfo
*raw_measure(QemuOpts
*opts
, BlockDriverState
*in_bs
,
349 BlockMeasureInfo
*info
;
353 required
= bdrv_getlength(in_bs
);
355 error_setg_errno(errp
, -required
, "Unable to get image size");
359 required
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
363 info
= g_new0(BlockMeasureInfo
, 1);
364 info
->required
= required
;
366 /* Unallocated sectors count towards the file size in raw images */
367 info
->fully_allocated
= info
->required
;
371 static int coroutine_fn
372 raw_co_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
374 return bdrv_co_get_info(bs
->file
->bs
, bdi
);
377 static void raw_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
380 /* To make it easier to protect the first sector, any probed
381 * image is restricted to read-modify-write on sub-sector
383 bs
->bl
.request_alignment
= BDRV_SECTOR_SIZE
;
387 static int coroutine_fn
raw_co_truncate(BlockDriverState
*bs
, int64_t offset
,
388 bool exact
, PreallocMode prealloc
,
389 BdrvRequestFlags flags
, Error
**errp
)
391 BDRVRawState
*s
= bs
->opaque
;
394 error_setg(errp
, "Cannot resize fixed-size raw disks");
398 if (INT64_MAX
- offset
< s
->offset
) {
399 error_setg(errp
, "Disk size too large for the chosen offset");
405 return bdrv_co_truncate(bs
->file
, offset
, exact
, prealloc
, flags
, errp
);
408 static void coroutine_fn
raw_co_eject(BlockDriverState
*bs
, bool eject_flag
)
410 bdrv_co_eject(bs
->file
->bs
, eject_flag
);
413 static void coroutine_fn
raw_co_lock_medium(BlockDriverState
*bs
, bool locked
)
415 bdrv_co_lock_medium(bs
->file
->bs
, locked
);
418 static int coroutine_fn
raw_co_ioctl(BlockDriverState
*bs
,
419 unsigned long int req
, void *buf
)
421 BDRVRawState
*s
= bs
->opaque
;
422 if (s
->offset
|| s
->has_size
) {
425 return bdrv_co_ioctl(bs
->file
->bs
, req
, buf
);
428 static int raw_has_zero_init(BlockDriverState
*bs
)
430 return bdrv_has_zero_init(bs
->file
->bs
);
433 static int coroutine_fn
raw_co_create_opts(BlockDriver
*drv
,
434 const char *filename
,
438 return bdrv_co_create_file(filename
, opts
, errp
);
441 static int raw_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
444 BDRVRawState
*s
= bs
->opaque
;
446 uint64_t offset
, size
;
447 BdrvChildRole file_role
;
450 ret
= raw_read_options(options
, &offset
, &has_size
, &size
, errp
);
456 * Without offset and a size limit, this driver behaves very much
457 * like a filter. With any such limit, it does not.
459 if (offset
|| has_size
) {
460 file_role
= BDRV_CHILD_DATA
| BDRV_CHILD_PRIMARY
;
462 file_role
= BDRV_CHILD_FILTERED
| BDRV_CHILD_PRIMARY
;
465 bdrv_open_child(NULL
, options
, "file", bs
, &child_of_bds
,
466 file_role
, false, errp
);
471 bs
->sg
= bdrv_is_sg(bs
->file
->bs
);
472 bs
->supported_write_flags
= BDRV_REQ_WRITE_UNCHANGED
|
473 (BDRV_REQ_FUA
& bs
->file
->bs
->supported_write_flags
);
474 bs
->supported_zero_flags
= BDRV_REQ_WRITE_UNCHANGED
|
475 ((BDRV_REQ_FUA
| BDRV_REQ_MAY_UNMAP
| BDRV_REQ_NO_FALLBACK
) &
476 bs
->file
->bs
->supported_zero_flags
);
477 bs
->supported_truncate_flags
= bs
->file
->bs
->supported_truncate_flags
&
480 if (bs
->probed
&& !bdrv_is_read_only(bs
)) {
481 bdrv_refresh_filename(bs
->file
->bs
);
483 "WARNING: Image format was not specified for '%s' and probing "
485 " Automatically detecting the format is dangerous for "
486 "raw images, write operations on block 0 will be restricted.\n"
487 " Specify the 'raw' format explicitly to remove the "
489 bs
->file
->bs
->filename
);
492 ret
= raw_apply_options(bs
, s
, offset
, has_size
, size
, errp
);
497 if (bdrv_is_sg(bs
) && (s
->offset
|| s
->has_size
)) {
498 error_setg(errp
, "Cannot use offset/size with SCSI generic devices");
505 static int raw_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
507 /* smallest possible positive score so that raw is used if and only if no
508 * other block driver works
513 static int raw_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
515 BDRVRawState
*s
= bs
->opaque
;
518 ret
= bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
523 if (!QEMU_IS_ALIGNED(s
->offset
, MAX(bsz
->log
, bsz
->phys
))) {
530 static int raw_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
532 BDRVRawState
*s
= bs
->opaque
;
533 if (s
->offset
|| s
->has_size
) {
536 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
539 static int coroutine_fn
raw_co_copy_range_from(BlockDriverState
*bs
,
545 BdrvRequestFlags read_flags
,
546 BdrvRequestFlags write_flags
)
550 ret
= raw_adjust_offset(bs
, &src_offset
, bytes
, false);
554 return bdrv_co_copy_range_from(bs
->file
, src_offset
, dst
, dst_offset
,
555 bytes
, read_flags
, write_flags
);
558 static int coroutine_fn
raw_co_copy_range_to(BlockDriverState
*bs
,
564 BdrvRequestFlags read_flags
,
565 BdrvRequestFlags write_flags
)
569 ret
= raw_adjust_offset(bs
, &dst_offset
, bytes
, true);
573 return bdrv_co_copy_range_to(src
, src_offset
, bs
->file
, dst_offset
, bytes
,
574 read_flags
, write_flags
);
577 static const char *const raw_strong_runtime_opts
[] = {
584 static void raw_cancel_in_flight(BlockDriverState
*bs
)
586 bdrv_cancel_in_flight(bs
->file
->bs
);
589 static void raw_child_perm(BlockDriverState
*bs
, BdrvChild
*c
,
591 BlockReopenQueue
*reopen_queue
,
592 uint64_t parent_perm
, uint64_t parent_shared
,
593 uint64_t *nperm
, uint64_t *nshared
)
595 bdrv_default_perms(bs
, c
, role
, reopen_queue
, parent_perm
,
596 parent_shared
, nperm
, nshared
);
599 * bdrv_default_perms() may add WRITE and/or RESIZE (see comment in
600 * bdrv_default_perms_for_storage() for an explanation) but we only need
601 * them if they are in parent_perm. Drop WRITE and RESIZE whenever possible
602 * to avoid permission conflicts.
604 *nperm
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
605 *nperm
|= parent_perm
& (BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
608 BlockDriver bdrv_raw
= {
609 .format_name
= "raw",
610 .instance_size
= sizeof(BDRVRawState
),
611 .bdrv_probe
= &raw_probe
,
612 .bdrv_reopen_prepare
= &raw_reopen_prepare
,
613 .bdrv_reopen_commit
= &raw_reopen_commit
,
614 .bdrv_reopen_abort
= &raw_reopen_abort
,
615 .bdrv_open
= &raw_open
,
616 .bdrv_child_perm
= raw_child_perm
,
617 .bdrv_co_create_opts
= &raw_co_create_opts
,
618 .bdrv_co_preadv
= &raw_co_preadv
,
619 .bdrv_co_pwritev
= &raw_co_pwritev
,
620 .bdrv_co_pwrite_zeroes
= &raw_co_pwrite_zeroes
,
621 .bdrv_co_pdiscard
= &raw_co_pdiscard
,
622 .bdrv_co_block_status
= &raw_co_block_status
,
623 .bdrv_co_copy_range_from
= &raw_co_copy_range_from
,
624 .bdrv_co_copy_range_to
= &raw_co_copy_range_to
,
625 .bdrv_co_truncate
= &raw_co_truncate
,
626 .bdrv_co_getlength
= &raw_co_getlength
,
628 .has_variable_length
= true,
629 .bdrv_measure
= &raw_measure
,
630 .bdrv_co_get_info
= &raw_co_get_info
,
631 .bdrv_refresh_limits
= &raw_refresh_limits
,
632 .bdrv_probe_blocksizes
= &raw_probe_blocksizes
,
633 .bdrv_probe_geometry
= &raw_probe_geometry
,
634 .bdrv_co_eject
= &raw_co_eject
,
635 .bdrv_co_lock_medium
= &raw_co_lock_medium
,
636 .bdrv_co_ioctl
= &raw_co_ioctl
,
637 .create_opts
= &raw_create_opts
,
638 .bdrv_has_zero_init
= &raw_has_zero_init
,
639 .strong_runtime_opts
= raw_strong_runtime_opts
,
640 .mutable_opts
= mutable_opts
,
641 .bdrv_cancel_in_flight
= raw_cancel_in_flight
,
644 static void bdrv_raw_init(void)
646 bdrv_register(&bdrv_raw
);
649 block_init(bdrv_raw_init
);