2 * QEMU Enhanced Disk Format
4 * Copyright IBM, Corp. 2010
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
8 * Anthony Liguori <aliguori@us.ibm.com>
10 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
11 * See the COPYING.LIB file in the top-level directory.
15 #include "qemu/timer.h"
18 #include "qapi/qmp/qerror.h"
19 #include "migration/migration.h"
21 static void qed_aio_cancel(BlockDriverAIOCB
*blockacb
)
23 QEDAIOCB
*acb
= (QEDAIOCB
*)blockacb
;
24 AioContext
*aio_context
= bdrv_get_aio_context(blockacb
->bs
);
25 bool finished
= false;
27 /* Wait for the request to finish */
28 acb
->finished
= &finished
;
30 aio_poll(aio_context
, true);
34 static const AIOCBInfo qed_aiocb_info
= {
35 .aiocb_size
= sizeof(QEDAIOCB
),
36 .cancel
= qed_aio_cancel
,
39 static int bdrv_qed_probe(const uint8_t *buf
, int buf_size
,
42 const QEDHeader
*header
= (const QEDHeader
*)buf
;
44 if (buf_size
< sizeof(*header
)) {
47 if (le32_to_cpu(header
->magic
) != QED_MAGIC
) {
54 * Check whether an image format is raw
56 * @fmt: Backing file format, may be NULL
58 static bool qed_fmt_is_raw(const char *fmt
)
60 return fmt
&& strcmp(fmt
, "raw") == 0;
63 static void qed_header_le_to_cpu(const QEDHeader
*le
, QEDHeader
*cpu
)
65 cpu
->magic
= le32_to_cpu(le
->magic
);
66 cpu
->cluster_size
= le32_to_cpu(le
->cluster_size
);
67 cpu
->table_size
= le32_to_cpu(le
->table_size
);
68 cpu
->header_size
= le32_to_cpu(le
->header_size
);
69 cpu
->features
= le64_to_cpu(le
->features
);
70 cpu
->compat_features
= le64_to_cpu(le
->compat_features
);
71 cpu
->autoclear_features
= le64_to_cpu(le
->autoclear_features
);
72 cpu
->l1_table_offset
= le64_to_cpu(le
->l1_table_offset
);
73 cpu
->image_size
= le64_to_cpu(le
->image_size
);
74 cpu
->backing_filename_offset
= le32_to_cpu(le
->backing_filename_offset
);
75 cpu
->backing_filename_size
= le32_to_cpu(le
->backing_filename_size
);
78 static void qed_header_cpu_to_le(const QEDHeader
*cpu
, QEDHeader
*le
)
80 le
->magic
= cpu_to_le32(cpu
->magic
);
81 le
->cluster_size
= cpu_to_le32(cpu
->cluster_size
);
82 le
->table_size
= cpu_to_le32(cpu
->table_size
);
83 le
->header_size
= cpu_to_le32(cpu
->header_size
);
84 le
->features
= cpu_to_le64(cpu
->features
);
85 le
->compat_features
= cpu_to_le64(cpu
->compat_features
);
86 le
->autoclear_features
= cpu_to_le64(cpu
->autoclear_features
);
87 le
->l1_table_offset
= cpu_to_le64(cpu
->l1_table_offset
);
88 le
->image_size
= cpu_to_le64(cpu
->image_size
);
89 le
->backing_filename_offset
= cpu_to_le32(cpu
->backing_filename_offset
);
90 le
->backing_filename_size
= cpu_to_le32(cpu
->backing_filename_size
);
93 int qed_write_header_sync(BDRVQEDState
*s
)
98 qed_header_cpu_to_le(&s
->header
, &le
);
99 ret
= bdrv_pwrite(s
->bs
->file
, 0, &le
, sizeof(le
));
100 if (ret
!= sizeof(le
)) {
115 static void qed_write_header_cb(void *opaque
, int ret
)
117 QEDWriteHeaderCB
*write_header_cb
= opaque
;
119 qemu_vfree(write_header_cb
->buf
);
120 gencb_complete(write_header_cb
, ret
);
123 static void qed_write_header_read_cb(void *opaque
, int ret
)
125 QEDWriteHeaderCB
*write_header_cb
= opaque
;
126 BDRVQEDState
*s
= write_header_cb
->s
;
129 qed_write_header_cb(write_header_cb
, ret
);
134 qed_header_cpu_to_le(&s
->header
, (QEDHeader
*)write_header_cb
->buf
);
136 bdrv_aio_writev(s
->bs
->file
, 0, &write_header_cb
->qiov
,
137 write_header_cb
->nsectors
, qed_write_header_cb
,
142 * Update header in-place (does not rewrite backing filename or other strings)
144 * This function only updates known header fields in-place and does not affect
145 * extra data after the QED header.
147 static void qed_write_header(BDRVQEDState
*s
, BlockDriverCompletionFunc cb
,
150 /* We must write full sectors for O_DIRECT but cannot necessarily generate
151 * the data following the header if an unrecognized compat feature is
152 * active. Therefore, first read the sectors containing the header, update
153 * them, and write back.
156 int nsectors
= (sizeof(QEDHeader
) + BDRV_SECTOR_SIZE
- 1) /
158 size_t len
= nsectors
* BDRV_SECTOR_SIZE
;
159 QEDWriteHeaderCB
*write_header_cb
= gencb_alloc(sizeof(*write_header_cb
),
162 write_header_cb
->s
= s
;
163 write_header_cb
->nsectors
= nsectors
;
164 write_header_cb
->buf
= qemu_blockalign(s
->bs
, len
);
165 write_header_cb
->iov
.iov_base
= write_header_cb
->buf
;
166 write_header_cb
->iov
.iov_len
= len
;
167 qemu_iovec_init_external(&write_header_cb
->qiov
, &write_header_cb
->iov
, 1);
169 bdrv_aio_readv(s
->bs
->file
, 0, &write_header_cb
->qiov
, nsectors
,
170 qed_write_header_read_cb
, write_header_cb
);
173 static uint64_t qed_max_image_size(uint32_t cluster_size
, uint32_t table_size
)
175 uint64_t table_entries
;
178 table_entries
= (table_size
* cluster_size
) / sizeof(uint64_t);
179 l2_size
= table_entries
* cluster_size
;
181 return l2_size
* table_entries
;
184 static bool qed_is_cluster_size_valid(uint32_t cluster_size
)
186 if (cluster_size
< QED_MIN_CLUSTER_SIZE
||
187 cluster_size
> QED_MAX_CLUSTER_SIZE
) {
190 if (cluster_size
& (cluster_size
- 1)) {
191 return false; /* not power of 2 */
196 static bool qed_is_table_size_valid(uint32_t table_size
)
198 if (table_size
< QED_MIN_TABLE_SIZE
||
199 table_size
> QED_MAX_TABLE_SIZE
) {
202 if (table_size
& (table_size
- 1)) {
203 return false; /* not power of 2 */
208 static bool qed_is_image_size_valid(uint64_t image_size
, uint32_t cluster_size
,
211 if (image_size
% BDRV_SECTOR_SIZE
!= 0) {
212 return false; /* not multiple of sector size */
214 if (image_size
> qed_max_image_size(cluster_size
, table_size
)) {
215 return false; /* image is too large */
221 * Read a string of known length from the image file
224 * @offset: File offset to start of string, in bytes
225 * @n: String length in bytes
226 * @buf: Destination buffer
227 * @buflen: Destination buffer length in bytes
228 * @ret: 0 on success, -errno on failure
230 * The string is NUL-terminated.
232 static int qed_read_string(BlockDriverState
*file
, uint64_t offset
, size_t n
,
233 char *buf
, size_t buflen
)
239 ret
= bdrv_pread(file
, offset
, buf
, n
);
248 * Allocate new clusters
251 * @n: Number of contiguous clusters to allocate
252 * @ret: Offset of first allocated cluster
254 * This function only produces the offset where the new clusters should be
255 * written. It updates BDRVQEDState but does not make any changes to the image
258 static uint64_t qed_alloc_clusters(BDRVQEDState
*s
, unsigned int n
)
260 uint64_t offset
= s
->file_size
;
261 s
->file_size
+= n
* s
->header
.cluster_size
;
265 QEDTable
*qed_alloc_table(BDRVQEDState
*s
)
267 /* Honor O_DIRECT memory alignment requirements */
268 return qemu_blockalign(s
->bs
,
269 s
->header
.cluster_size
* s
->header
.table_size
);
273 * Allocate a new zeroed L2 table
275 static CachedL2Table
*qed_new_l2_table(BDRVQEDState
*s
)
277 CachedL2Table
*l2_table
= qed_alloc_l2_cache_entry(&s
->l2_cache
);
279 l2_table
->table
= qed_alloc_table(s
);
280 l2_table
->offset
= qed_alloc_clusters(s
, s
->header
.table_size
);
282 memset(l2_table
->table
->offsets
, 0,
283 s
->header
.cluster_size
* s
->header
.table_size
);
287 static void qed_aio_next_io(void *opaque
, int ret
);
289 static void qed_plug_allocating_write_reqs(BDRVQEDState
*s
)
291 assert(!s
->allocating_write_reqs_plugged
);
293 s
->allocating_write_reqs_plugged
= true;
296 static void qed_unplug_allocating_write_reqs(BDRVQEDState
*s
)
300 assert(s
->allocating_write_reqs_plugged
);
302 s
->allocating_write_reqs_plugged
= false;
304 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
306 qed_aio_next_io(acb
, 0);
310 static void qed_finish_clear_need_check(void *opaque
, int ret
)
315 static void qed_flush_after_clear_need_check(void *opaque
, int ret
)
317 BDRVQEDState
*s
= opaque
;
319 bdrv_aio_flush(s
->bs
, qed_finish_clear_need_check
, s
);
321 /* No need to wait until flush completes */
322 qed_unplug_allocating_write_reqs(s
);
325 static void qed_clear_need_check(void *opaque
, int ret
)
327 BDRVQEDState
*s
= opaque
;
330 qed_unplug_allocating_write_reqs(s
);
334 s
->header
.features
&= ~QED_F_NEED_CHECK
;
335 qed_write_header(s
, qed_flush_after_clear_need_check
, s
);
338 static void qed_need_check_timer_cb(void *opaque
)
340 BDRVQEDState
*s
= opaque
;
342 /* The timer should only fire when allocating writes have drained */
343 assert(!QSIMPLEQ_FIRST(&s
->allocating_write_reqs
));
345 trace_qed_need_check_timer_cb(s
);
347 qed_plug_allocating_write_reqs(s
);
349 /* Ensure writes are on disk before clearing flag */
350 bdrv_aio_flush(s
->bs
, qed_clear_need_check
, s
);
353 static void qed_start_need_check_timer(BDRVQEDState
*s
)
355 trace_qed_start_need_check_timer(s
);
357 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
360 timer_mod(s
->need_check_timer
, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
) +
361 get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT
);
364 /* It's okay to call this multiple times or when no timer is started */
365 static void qed_cancel_need_check_timer(BDRVQEDState
*s
)
367 trace_qed_cancel_need_check_timer(s
);
368 timer_del(s
->need_check_timer
);
371 static void bdrv_qed_rebind(BlockDriverState
*bs
)
373 BDRVQEDState
*s
= bs
->opaque
;
377 static void bdrv_qed_detach_aio_context(BlockDriverState
*bs
)
379 BDRVQEDState
*s
= bs
->opaque
;
381 qed_cancel_need_check_timer(s
);
382 timer_free(s
->need_check_timer
);
385 static void bdrv_qed_attach_aio_context(BlockDriverState
*bs
,
386 AioContext
*new_context
)
388 BDRVQEDState
*s
= bs
->opaque
;
390 s
->need_check_timer
= aio_timer_new(new_context
,
391 QEMU_CLOCK_VIRTUAL
, SCALE_NS
,
392 qed_need_check_timer_cb
, s
);
393 if (s
->header
.features
& QED_F_NEED_CHECK
) {
394 qed_start_need_check_timer(s
);
398 static int bdrv_qed_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
401 BDRVQEDState
*s
= bs
->opaque
;
407 QSIMPLEQ_INIT(&s
->allocating_write_reqs
);
409 ret
= bdrv_pread(bs
->file
, 0, &le_header
, sizeof(le_header
));
413 qed_header_le_to_cpu(&le_header
, &s
->header
);
415 if (s
->header
.magic
!= QED_MAGIC
) {
416 error_setg(errp
, "Image not in QED format");
419 if (s
->header
.features
& ~QED_FEATURE_MASK
) {
420 /* image uses unsupported feature bits */
422 snprintf(buf
, sizeof(buf
), "%" PRIx64
,
423 s
->header
.features
& ~QED_FEATURE_MASK
);
424 error_set(errp
, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
,
425 bs
->device_name
, "QED", buf
);
428 if (!qed_is_cluster_size_valid(s
->header
.cluster_size
)) {
432 /* Round down file size to the last cluster */
433 file_size
= bdrv_getlength(bs
->file
);
437 s
->file_size
= qed_start_of_cluster(s
, file_size
);
439 if (!qed_is_table_size_valid(s
->header
.table_size
)) {
442 if (!qed_is_image_size_valid(s
->header
.image_size
,
443 s
->header
.cluster_size
,
444 s
->header
.table_size
)) {
447 if (!qed_check_table_offset(s
, s
->header
.l1_table_offset
)) {
451 s
->table_nelems
= (s
->header
.cluster_size
* s
->header
.table_size
) /
453 s
->l2_shift
= ffs(s
->header
.cluster_size
) - 1;
454 s
->l2_mask
= s
->table_nelems
- 1;
455 s
->l1_shift
= s
->l2_shift
+ ffs(s
->table_nelems
) - 1;
457 if ((s
->header
.features
& QED_F_BACKING_FILE
)) {
458 if ((uint64_t)s
->header
.backing_filename_offset
+
459 s
->header
.backing_filename_size
>
460 s
->header
.cluster_size
* s
->header
.header_size
) {
464 ret
= qed_read_string(bs
->file
, s
->header
.backing_filename_offset
,
465 s
->header
.backing_filename_size
, bs
->backing_file
,
466 sizeof(bs
->backing_file
));
471 if (s
->header
.features
& QED_F_BACKING_FORMAT_NO_PROBE
) {
472 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), "raw");
476 /* Reset unknown autoclear feature bits. This is a backwards
477 * compatibility mechanism that allows images to be opened by older
478 * programs, which "knock out" unknown feature bits. When an image is
479 * opened by a newer program again it can detect that the autoclear
480 * feature is no longer valid.
482 if ((s
->header
.autoclear_features
& ~QED_AUTOCLEAR_FEATURE_MASK
) != 0 &&
483 !bdrv_is_read_only(bs
->file
) && !(flags
& BDRV_O_INCOMING
)) {
484 s
->header
.autoclear_features
&= QED_AUTOCLEAR_FEATURE_MASK
;
486 ret
= qed_write_header_sync(s
);
491 /* From here on only known autoclear feature bits are valid */
492 bdrv_flush(bs
->file
);
495 s
->l1_table
= qed_alloc_table(s
);
496 qed_init_l2_cache(&s
->l2_cache
);
498 ret
= qed_read_l1_table_sync(s
);
503 /* If image was not closed cleanly, check consistency */
504 if (!(flags
& BDRV_O_CHECK
) && (s
->header
.features
& QED_F_NEED_CHECK
)) {
505 /* Read-only images cannot be fixed. There is no risk of corruption
506 * since write operations are not possible. Therefore, allow
507 * potentially inconsistent images to be opened read-only. This can
508 * aid data recovery from an otherwise inconsistent image.
510 if (!bdrv_is_read_only(bs
->file
) &&
511 !(flags
& BDRV_O_INCOMING
)) {
512 BdrvCheckResult result
= {0};
514 ret
= qed_check(s
, &result
, true);
521 bdrv_qed_attach_aio_context(bs
, bdrv_get_aio_context(bs
));
525 qed_free_l2_cache(&s
->l2_cache
);
526 qemu_vfree(s
->l1_table
);
531 static void bdrv_qed_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
533 BDRVQEDState
*s
= bs
->opaque
;
535 bs
->bl
.write_zeroes_alignment
= s
->header
.cluster_size
>> BDRV_SECTOR_BITS
;
538 /* We have nothing to do for QED reopen, stubs just return
540 static int bdrv_qed_reopen_prepare(BDRVReopenState
*state
,
541 BlockReopenQueue
*queue
, Error
**errp
)
546 static void bdrv_qed_close(BlockDriverState
*bs
)
548 BDRVQEDState
*s
= bs
->opaque
;
550 bdrv_qed_detach_aio_context(bs
);
552 /* Ensure writes reach stable storage */
553 bdrv_flush(bs
->file
);
555 /* Clean shutdown, no check required on next open */
556 if (s
->header
.features
& QED_F_NEED_CHECK
) {
557 s
->header
.features
&= ~QED_F_NEED_CHECK
;
558 qed_write_header_sync(s
);
561 qed_free_l2_cache(&s
->l2_cache
);
562 qemu_vfree(s
->l1_table
);
565 static int qed_create(const char *filename
, uint32_t cluster_size
,
566 uint64_t image_size
, uint32_t table_size
,
567 const char *backing_file
, const char *backing_fmt
,
568 QemuOpts
*opts
, Error
**errp
)
572 .cluster_size
= cluster_size
,
573 .table_size
= table_size
,
576 .compat_features
= 0,
577 .l1_table_offset
= cluster_size
,
578 .image_size
= image_size
,
581 uint8_t *l1_table
= NULL
;
582 size_t l1_size
= header
.cluster_size
* header
.table_size
;
583 Error
*local_err
= NULL
;
585 BlockDriverState
*bs
;
587 ret
= bdrv_create_file(filename
, opts
, &local_err
);
589 error_propagate(errp
, local_err
);
594 ret
= bdrv_open(&bs
, filename
, NULL
, NULL
,
595 BDRV_O_RDWR
| BDRV_O_CACHE_WB
| BDRV_O_PROTOCOL
, NULL
,
598 error_propagate(errp
, local_err
);
602 /* File must start empty and grow, check truncate is supported */
603 ret
= bdrv_truncate(bs
, 0);
609 header
.features
|= QED_F_BACKING_FILE
;
610 header
.backing_filename_offset
= sizeof(le_header
);
611 header
.backing_filename_size
= strlen(backing_file
);
613 if (qed_fmt_is_raw(backing_fmt
)) {
614 header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
618 qed_header_cpu_to_le(&header
, &le_header
);
619 ret
= bdrv_pwrite(bs
, 0, &le_header
, sizeof(le_header
));
623 ret
= bdrv_pwrite(bs
, sizeof(le_header
), backing_file
,
624 header
.backing_filename_size
);
629 l1_table
= g_malloc0(l1_size
);
630 ret
= bdrv_pwrite(bs
, header
.l1_table_offset
, l1_table
, l1_size
);
635 ret
= 0; /* success */
642 static int bdrv_qed_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
644 uint64_t image_size
= 0;
645 uint32_t cluster_size
= QED_DEFAULT_CLUSTER_SIZE
;
646 uint32_t table_size
= QED_DEFAULT_TABLE_SIZE
;
647 char *backing_file
= NULL
;
648 char *backing_fmt
= NULL
;
651 image_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0);
652 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
653 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
654 cluster_size
= qemu_opt_get_size_del(opts
,
655 BLOCK_OPT_CLUSTER_SIZE
,
656 QED_DEFAULT_CLUSTER_SIZE
);
657 table_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_TABLE_SIZE
,
658 QED_DEFAULT_TABLE_SIZE
);
660 if (!qed_is_cluster_size_valid(cluster_size
)) {
661 error_setg(errp
, "QED cluster size must be within range [%u, %u] "
663 QED_MIN_CLUSTER_SIZE
, QED_MAX_CLUSTER_SIZE
);
667 if (!qed_is_table_size_valid(table_size
)) {
668 error_setg(errp
, "QED table size must be within range [%u, %u] "
670 QED_MIN_TABLE_SIZE
, QED_MAX_TABLE_SIZE
);
674 if (!qed_is_image_size_valid(image_size
, cluster_size
, table_size
)) {
675 error_setg(errp
, "QED image size must be a non-zero multiple of "
676 "cluster size and less than %" PRIu64
" bytes",
677 qed_max_image_size(cluster_size
, table_size
));
682 ret
= qed_create(filename
, cluster_size
, image_size
, table_size
,
683 backing_file
, backing_fmt
, opts
, errp
);
686 g_free(backing_file
);
692 BlockDriverState
*bs
;
699 static void qed_is_allocated_cb(void *opaque
, int ret
, uint64_t offset
, size_t len
)
701 QEDIsAllocatedCB
*cb
= opaque
;
702 BDRVQEDState
*s
= cb
->bs
->opaque
;
703 *cb
->pnum
= len
/ BDRV_SECTOR_SIZE
;
705 case QED_CLUSTER_FOUND
:
706 offset
|= qed_offset_into_cluster(s
, cb
->pos
);
707 cb
->status
= BDRV_BLOCK_DATA
| BDRV_BLOCK_OFFSET_VALID
| offset
;
709 case QED_CLUSTER_ZERO
:
710 cb
->status
= BDRV_BLOCK_ZERO
;
723 qemu_coroutine_enter(cb
->co
, NULL
);
727 static int64_t coroutine_fn
bdrv_qed_co_get_block_status(BlockDriverState
*bs
,
729 int nb_sectors
, int *pnum
)
731 BDRVQEDState
*s
= bs
->opaque
;
732 size_t len
= (size_t)nb_sectors
* BDRV_SECTOR_SIZE
;
733 QEDIsAllocatedCB cb
= {
735 .pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
,
736 .status
= BDRV_BLOCK_OFFSET_MASK
,
739 QEDRequest request
= { .l2_table
= NULL
};
741 qed_find_cluster(s
, &request
, cb
.pos
, len
, qed_is_allocated_cb
, &cb
);
743 /* Now sleep if the callback wasn't invoked immediately */
744 while (cb
.status
== BDRV_BLOCK_OFFSET_MASK
) {
745 cb
.co
= qemu_coroutine_self();
746 qemu_coroutine_yield();
749 qed_unref_l2_cache_entry(request
.l2_table
);
754 static BDRVQEDState
*acb_to_s(QEDAIOCB
*acb
)
756 return acb
->common
.bs
->opaque
;
760 * Read from the backing file or zero-fill if no backing file
763 * @pos: Byte position in device
764 * @qiov: Destination I/O vector
765 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
766 * @cb: Completion function
767 * @opaque: User data for completion function
769 * This function reads qiov->size bytes starting at pos from the backing file.
770 * If there is no backing file then zeroes are read.
772 static void qed_read_backing_file(BDRVQEDState
*s
, uint64_t pos
,
774 QEMUIOVector
**backing_qiov
,
775 BlockDriverCompletionFunc
*cb
, void *opaque
)
777 uint64_t backing_length
= 0;
780 /* If there is a backing file, get its length. Treat the absence of a
781 * backing file like a zero length backing file.
783 if (s
->bs
->backing_hd
) {
784 int64_t l
= bdrv_getlength(s
->bs
->backing_hd
);
792 /* Zero all sectors if reading beyond the end of the backing file */
793 if (pos
>= backing_length
||
794 pos
+ qiov
->size
> backing_length
) {
795 qemu_iovec_memset(qiov
, 0, 0, qiov
->size
);
798 /* Complete now if there are no backing file sectors to read */
799 if (pos
>= backing_length
) {
804 /* If the read straddles the end of the backing file, shorten it */
805 size
= MIN((uint64_t)backing_length
- pos
, qiov
->size
);
807 assert(*backing_qiov
== NULL
);
808 *backing_qiov
= g_new(QEMUIOVector
, 1);
809 qemu_iovec_init(*backing_qiov
, qiov
->niov
);
810 qemu_iovec_concat(*backing_qiov
, qiov
, 0, size
);
812 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_READ_BACKING_AIO
);
813 bdrv_aio_readv(s
->bs
->backing_hd
, pos
/ BDRV_SECTOR_SIZE
,
814 *backing_qiov
, size
/ BDRV_SECTOR_SIZE
, cb
, opaque
);
821 QEMUIOVector
*backing_qiov
;
824 } CopyFromBackingFileCB
;
826 static void qed_copy_from_backing_file_cb(void *opaque
, int ret
)
828 CopyFromBackingFileCB
*copy_cb
= opaque
;
829 qemu_vfree(copy_cb
->iov
.iov_base
);
830 gencb_complete(©_cb
->gencb
, ret
);
833 static void qed_copy_from_backing_file_write(void *opaque
, int ret
)
835 CopyFromBackingFileCB
*copy_cb
= opaque
;
836 BDRVQEDState
*s
= copy_cb
->s
;
838 if (copy_cb
->backing_qiov
) {
839 qemu_iovec_destroy(copy_cb
->backing_qiov
);
840 g_free(copy_cb
->backing_qiov
);
841 copy_cb
->backing_qiov
= NULL
;
845 qed_copy_from_backing_file_cb(copy_cb
, ret
);
849 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_COW_WRITE
);
850 bdrv_aio_writev(s
->bs
->file
, copy_cb
->offset
/ BDRV_SECTOR_SIZE
,
851 ©_cb
->qiov
, copy_cb
->qiov
.size
/ BDRV_SECTOR_SIZE
,
852 qed_copy_from_backing_file_cb
, copy_cb
);
856 * Copy data from backing file into the image
859 * @pos: Byte position in device
860 * @len: Number of bytes
861 * @offset: Byte offset in image file
862 * @cb: Completion function
863 * @opaque: User data for completion function
865 static void qed_copy_from_backing_file(BDRVQEDState
*s
, uint64_t pos
,
866 uint64_t len
, uint64_t offset
,
867 BlockDriverCompletionFunc
*cb
,
870 CopyFromBackingFileCB
*copy_cb
;
872 /* Skip copy entirely if there is no work to do */
878 copy_cb
= gencb_alloc(sizeof(*copy_cb
), cb
, opaque
);
880 copy_cb
->offset
= offset
;
881 copy_cb
->backing_qiov
= NULL
;
882 copy_cb
->iov
.iov_base
= qemu_blockalign(s
->bs
, len
);
883 copy_cb
->iov
.iov_len
= len
;
884 qemu_iovec_init_external(©_cb
->qiov
, ©_cb
->iov
, 1);
886 qed_read_backing_file(s
, pos
, ©_cb
->qiov
, ©_cb
->backing_qiov
,
887 qed_copy_from_backing_file_write
, copy_cb
);
891 * Link one or more contiguous clusters into a table
895 * @index: First cluster index
896 * @n: Number of contiguous clusters
897 * @cluster: First cluster offset
899 * The cluster offset may be an allocated byte offset in the image file, the
900 * zero cluster marker, or the unallocated cluster marker.
902 static void qed_update_l2_table(BDRVQEDState
*s
, QEDTable
*table
, int index
,
903 unsigned int n
, uint64_t cluster
)
906 for (i
= index
; i
< index
+ n
; i
++) {
907 table
->offsets
[i
] = cluster
;
908 if (!qed_offset_is_unalloc_cluster(cluster
) &&
909 !qed_offset_is_zero_cluster(cluster
)) {
910 cluster
+= s
->header
.cluster_size
;
915 static void qed_aio_complete_bh(void *opaque
)
917 QEDAIOCB
*acb
= opaque
;
918 BlockDriverCompletionFunc
*cb
= acb
->common
.cb
;
919 void *user_opaque
= acb
->common
.opaque
;
920 int ret
= acb
->bh_ret
;
921 bool *finished
= acb
->finished
;
923 qemu_bh_delete(acb
->bh
);
924 qemu_aio_release(acb
);
926 /* Invoke callback */
927 cb(user_opaque
, ret
);
929 /* Signal cancel completion */
935 static void qed_aio_complete(QEDAIOCB
*acb
, int ret
)
937 BDRVQEDState
*s
= acb_to_s(acb
);
939 trace_qed_aio_complete(s
, acb
, ret
);
942 qemu_iovec_destroy(&acb
->cur_qiov
);
943 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
945 /* Free the buffer we may have allocated for zero writes */
946 if (acb
->flags
& QED_AIOCB_ZERO
) {
947 qemu_vfree(acb
->qiov
->iov
[0].iov_base
);
948 acb
->qiov
->iov
[0].iov_base
= NULL
;
951 /* Arrange for a bh to invoke the completion function */
953 acb
->bh
= aio_bh_new(bdrv_get_aio_context(acb
->common
.bs
),
954 qed_aio_complete_bh
, acb
);
955 qemu_bh_schedule(acb
->bh
);
957 /* Start next allocating write request waiting behind this one. Note that
958 * requests enqueue themselves when they first hit an unallocated cluster
959 * but they wait until the entire request is finished before waking up the
960 * next request in the queue. This ensures that we don't cycle through
961 * requests multiple times but rather finish one at a time completely.
963 if (acb
== QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
964 QSIMPLEQ_REMOVE_HEAD(&s
->allocating_write_reqs
, next
);
965 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
967 qed_aio_next_io(acb
, 0);
968 } else if (s
->header
.features
& QED_F_NEED_CHECK
) {
969 qed_start_need_check_timer(s
);
975 * Commit the current L2 table to the cache
977 static void qed_commit_l2_update(void *opaque
, int ret
)
979 QEDAIOCB
*acb
= opaque
;
980 BDRVQEDState
*s
= acb_to_s(acb
);
981 CachedL2Table
*l2_table
= acb
->request
.l2_table
;
982 uint64_t l2_offset
= l2_table
->offset
;
984 qed_commit_l2_cache_entry(&s
->l2_cache
, l2_table
);
986 /* This is guaranteed to succeed because we just committed the entry to the
989 acb
->request
.l2_table
= qed_find_l2_cache_entry(&s
->l2_cache
, l2_offset
);
990 assert(acb
->request
.l2_table
!= NULL
);
992 qed_aio_next_io(opaque
, ret
);
996 * Update L1 table with new L2 table offset and write it out
998 static void qed_aio_write_l1_update(void *opaque
, int ret
)
1000 QEDAIOCB
*acb
= opaque
;
1001 BDRVQEDState
*s
= acb_to_s(acb
);
1005 qed_aio_complete(acb
, ret
);
1009 index
= qed_l1_index(s
, acb
->cur_pos
);
1010 s
->l1_table
->offsets
[index
] = acb
->request
.l2_table
->offset
;
1012 qed_write_l1_table(s
, index
, 1, qed_commit_l2_update
, acb
);
1016 * Update L2 table with new cluster offsets and write them out
1018 static void qed_aio_write_l2_update(QEDAIOCB
*acb
, int ret
, uint64_t offset
)
1020 BDRVQEDState
*s
= acb_to_s(acb
);
1021 bool need_alloc
= acb
->find_cluster_ret
== QED_CLUSTER_L1
;
1029 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
1030 acb
->request
.l2_table
= qed_new_l2_table(s
);
1033 index
= qed_l2_index(s
, acb
->cur_pos
);
1034 qed_update_l2_table(s
, acb
->request
.l2_table
->table
, index
, acb
->cur_nclusters
,
1038 /* Write out the whole new L2 table */
1039 qed_write_l2_table(s
, &acb
->request
, 0, s
->table_nelems
, true,
1040 qed_aio_write_l1_update
, acb
);
1042 /* Write out only the updated part of the L2 table */
1043 qed_write_l2_table(s
, &acb
->request
, index
, acb
->cur_nclusters
, false,
1044 qed_aio_next_io
, acb
);
1049 qed_aio_complete(acb
, ret
);
1052 static void qed_aio_write_l2_update_cb(void *opaque
, int ret
)
1054 QEDAIOCB
*acb
= opaque
;
1055 qed_aio_write_l2_update(acb
, ret
, acb
->cur_cluster
);
1059 * Flush new data clusters before updating the L2 table
1061 * This flush is necessary when a backing file is in use. A crash during an
1062 * allocating write could result in empty clusters in the image. If the write
1063 * only touched a subregion of the cluster, then backing image sectors have
1064 * been lost in the untouched region. The solution is to flush after writing a
1065 * new data cluster and before updating the L2 table.
1067 static void qed_aio_write_flush_before_l2_update(void *opaque
, int ret
)
1069 QEDAIOCB
*acb
= opaque
;
1070 BDRVQEDState
*s
= acb_to_s(acb
);
1072 if (!bdrv_aio_flush(s
->bs
->file
, qed_aio_write_l2_update_cb
, opaque
)) {
1073 qed_aio_complete(acb
, -EIO
);
1078 * Write data to the image file
1080 static void qed_aio_write_main(void *opaque
, int ret
)
1082 QEDAIOCB
*acb
= opaque
;
1083 BDRVQEDState
*s
= acb_to_s(acb
);
1084 uint64_t offset
= acb
->cur_cluster
+
1085 qed_offset_into_cluster(s
, acb
->cur_pos
);
1086 BlockDriverCompletionFunc
*next_fn
;
1088 trace_qed_aio_write_main(s
, acb
, ret
, offset
, acb
->cur_qiov
.size
);
1091 qed_aio_complete(acb
, ret
);
1095 if (acb
->find_cluster_ret
== QED_CLUSTER_FOUND
) {
1096 next_fn
= qed_aio_next_io
;
1098 if (s
->bs
->backing_hd
) {
1099 next_fn
= qed_aio_write_flush_before_l2_update
;
1101 next_fn
= qed_aio_write_l2_update_cb
;
1105 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_WRITE_AIO
);
1106 bdrv_aio_writev(s
->bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1107 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1112 * Populate back untouched region of new data cluster
1114 static void qed_aio_write_postfill(void *opaque
, int ret
)
1116 QEDAIOCB
*acb
= opaque
;
1117 BDRVQEDState
*s
= acb_to_s(acb
);
1118 uint64_t start
= acb
->cur_pos
+ acb
->cur_qiov
.size
;
1120 qed_start_of_cluster(s
, start
+ s
->header
.cluster_size
- 1) - start
;
1121 uint64_t offset
= acb
->cur_cluster
+
1122 qed_offset_into_cluster(s
, acb
->cur_pos
) +
1126 qed_aio_complete(acb
, ret
);
1130 trace_qed_aio_write_postfill(s
, acb
, start
, len
, offset
);
1131 qed_copy_from_backing_file(s
, start
, len
, offset
,
1132 qed_aio_write_main
, acb
);
1136 * Populate front untouched region of new data cluster
1138 static void qed_aio_write_prefill(void *opaque
, int ret
)
1140 QEDAIOCB
*acb
= opaque
;
1141 BDRVQEDState
*s
= acb_to_s(acb
);
1142 uint64_t start
= qed_start_of_cluster(s
, acb
->cur_pos
);
1143 uint64_t len
= qed_offset_into_cluster(s
, acb
->cur_pos
);
1145 trace_qed_aio_write_prefill(s
, acb
, start
, len
, acb
->cur_cluster
);
1146 qed_copy_from_backing_file(s
, start
, len
, acb
->cur_cluster
,
1147 qed_aio_write_postfill
, acb
);
1151 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1153 static bool qed_should_set_need_check(BDRVQEDState
*s
)
1155 /* The flush before L2 update path ensures consistency */
1156 if (s
->bs
->backing_hd
) {
1160 return !(s
->header
.features
& QED_F_NEED_CHECK
);
1163 static void qed_aio_write_zero_cluster(void *opaque
, int ret
)
1165 QEDAIOCB
*acb
= opaque
;
1168 qed_aio_complete(acb
, ret
);
1172 qed_aio_write_l2_update(acb
, 0, 1);
1176 * Write new data cluster
1178 * @acb: Write request
1179 * @len: Length in bytes
1181 * This path is taken when writing to previously unallocated clusters.
1183 static void qed_aio_write_alloc(QEDAIOCB
*acb
, size_t len
)
1185 BDRVQEDState
*s
= acb_to_s(acb
);
1186 BlockDriverCompletionFunc
*cb
;
1188 /* Cancel timer when the first allocating request comes in */
1189 if (QSIMPLEQ_EMPTY(&s
->allocating_write_reqs
)) {
1190 qed_cancel_need_check_timer(s
);
1193 /* Freeze this request if another allocating write is in progress */
1194 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
1195 QSIMPLEQ_INSERT_TAIL(&s
->allocating_write_reqs
, acb
, next
);
1197 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
) ||
1198 s
->allocating_write_reqs_plugged
) {
1199 return; /* wait for existing request to finish */
1202 acb
->cur_nclusters
= qed_bytes_to_clusters(s
,
1203 qed_offset_into_cluster(s
, acb
->cur_pos
) + len
);
1204 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1206 if (acb
->flags
& QED_AIOCB_ZERO
) {
1207 /* Skip ahead if the clusters are already zero */
1208 if (acb
->find_cluster_ret
== QED_CLUSTER_ZERO
) {
1209 qed_aio_next_io(acb
, 0);
1213 cb
= qed_aio_write_zero_cluster
;
1215 cb
= qed_aio_write_prefill
;
1216 acb
->cur_cluster
= qed_alloc_clusters(s
, acb
->cur_nclusters
);
1219 if (qed_should_set_need_check(s
)) {
1220 s
->header
.features
|= QED_F_NEED_CHECK
;
1221 qed_write_header(s
, cb
, acb
);
1228 * Write data cluster in place
1230 * @acb: Write request
1231 * @offset: Cluster offset in bytes
1232 * @len: Length in bytes
1234 * This path is taken when writing to already allocated clusters.
1236 static void qed_aio_write_inplace(QEDAIOCB
*acb
, uint64_t offset
, size_t len
)
1238 /* Allocate buffer for zero writes */
1239 if (acb
->flags
& QED_AIOCB_ZERO
) {
1240 struct iovec
*iov
= acb
->qiov
->iov
;
1242 if (!iov
->iov_base
) {
1243 iov
->iov_base
= qemu_try_blockalign(acb
->common
.bs
, iov
->iov_len
);
1244 if (iov
->iov_base
== NULL
) {
1245 qed_aio_complete(acb
, -ENOMEM
);
1248 memset(iov
->iov_base
, 0, iov
->iov_len
);
1252 /* Calculate the I/O vector */
1253 acb
->cur_cluster
= offset
;
1254 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1256 /* Do the actual write */
1257 qed_aio_write_main(acb
, 0);
1261 * Write data cluster
1263 * @opaque: Write request
1264 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1266 * @offset: Cluster offset in bytes
1267 * @len: Length in bytes
1269 * Callback from qed_find_cluster().
1271 static void qed_aio_write_data(void *opaque
, int ret
,
1272 uint64_t offset
, size_t len
)
1274 QEDAIOCB
*acb
= opaque
;
1276 trace_qed_aio_write_data(acb_to_s(acb
), acb
, ret
, offset
, len
);
1278 acb
->find_cluster_ret
= ret
;
1281 case QED_CLUSTER_FOUND
:
1282 qed_aio_write_inplace(acb
, offset
, len
);
1285 case QED_CLUSTER_L2
:
1286 case QED_CLUSTER_L1
:
1287 case QED_CLUSTER_ZERO
:
1288 qed_aio_write_alloc(acb
, len
);
1292 qed_aio_complete(acb
, ret
);
1300 * @opaque: Read request
1301 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1303 * @offset: Cluster offset in bytes
1304 * @len: Length in bytes
1306 * Callback from qed_find_cluster().
1308 static void qed_aio_read_data(void *opaque
, int ret
,
1309 uint64_t offset
, size_t len
)
1311 QEDAIOCB
*acb
= opaque
;
1312 BDRVQEDState
*s
= acb_to_s(acb
);
1313 BlockDriverState
*bs
= acb
->common
.bs
;
1315 /* Adjust offset into cluster */
1316 offset
+= qed_offset_into_cluster(s
, acb
->cur_pos
);
1318 trace_qed_aio_read_data(s
, acb
, ret
, offset
, len
);
1324 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1326 /* Handle zero cluster and backing file reads */
1327 if (ret
== QED_CLUSTER_ZERO
) {
1328 qemu_iovec_memset(&acb
->cur_qiov
, 0, 0, acb
->cur_qiov
.size
);
1329 qed_aio_next_io(acb
, 0);
1331 } else if (ret
!= QED_CLUSTER_FOUND
) {
1332 qed_read_backing_file(s
, acb
->cur_pos
, &acb
->cur_qiov
,
1333 &acb
->backing_qiov
, qed_aio_next_io
, acb
);
1337 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1338 bdrv_aio_readv(bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1339 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1340 qed_aio_next_io
, acb
);
1344 qed_aio_complete(acb
, ret
);
1348 * Begin next I/O or complete the request
1350 static void qed_aio_next_io(void *opaque
, int ret
)
1352 QEDAIOCB
*acb
= opaque
;
1353 BDRVQEDState
*s
= acb_to_s(acb
);
1354 QEDFindClusterFunc
*io_fn
= (acb
->flags
& QED_AIOCB_WRITE
) ?
1355 qed_aio_write_data
: qed_aio_read_data
;
1357 trace_qed_aio_next_io(s
, acb
, ret
, acb
->cur_pos
+ acb
->cur_qiov
.size
);
1359 if (acb
->backing_qiov
) {
1360 qemu_iovec_destroy(acb
->backing_qiov
);
1361 g_free(acb
->backing_qiov
);
1362 acb
->backing_qiov
= NULL
;
1365 /* Handle I/O error */
1367 qed_aio_complete(acb
, ret
);
1371 acb
->qiov_offset
+= acb
->cur_qiov
.size
;
1372 acb
->cur_pos
+= acb
->cur_qiov
.size
;
1373 qemu_iovec_reset(&acb
->cur_qiov
);
1375 /* Complete request */
1376 if (acb
->cur_pos
>= acb
->end_pos
) {
1377 qed_aio_complete(acb
, 0);
1381 /* Find next cluster and start I/O */
1382 qed_find_cluster(s
, &acb
->request
,
1383 acb
->cur_pos
, acb
->end_pos
- acb
->cur_pos
,
1387 static BlockDriverAIOCB
*qed_aio_setup(BlockDriverState
*bs
,
1389 QEMUIOVector
*qiov
, int nb_sectors
,
1390 BlockDriverCompletionFunc
*cb
,
1391 void *opaque
, int flags
)
1393 QEDAIOCB
*acb
= qemu_aio_get(&qed_aiocb_info
, bs
, cb
, opaque
);
1395 trace_qed_aio_setup(bs
->opaque
, acb
, sector_num
, nb_sectors
,
1399 acb
->finished
= NULL
;
1401 acb
->qiov_offset
= 0;
1402 acb
->cur_pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
;
1403 acb
->end_pos
= acb
->cur_pos
+ nb_sectors
* BDRV_SECTOR_SIZE
;
1404 acb
->backing_qiov
= NULL
;
1405 acb
->request
.l2_table
= NULL
;
1406 qemu_iovec_init(&acb
->cur_qiov
, qiov
->niov
);
1409 qed_aio_next_io(acb
, 0);
1410 return &acb
->common
;
1413 static BlockDriverAIOCB
*bdrv_qed_aio_readv(BlockDriverState
*bs
,
1415 QEMUIOVector
*qiov
, int nb_sectors
,
1416 BlockDriverCompletionFunc
*cb
,
1419 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
, opaque
, 0);
1422 static BlockDriverAIOCB
*bdrv_qed_aio_writev(BlockDriverState
*bs
,
1424 QEMUIOVector
*qiov
, int nb_sectors
,
1425 BlockDriverCompletionFunc
*cb
,
1428 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
,
1429 opaque
, QED_AIOCB_WRITE
);
1438 static void coroutine_fn
qed_co_write_zeroes_cb(void *opaque
, int ret
)
1440 QEDWriteZeroesCB
*cb
= opaque
;
1445 qemu_coroutine_enter(cb
->co
, NULL
);
1449 static int coroutine_fn
bdrv_qed_co_write_zeroes(BlockDriverState
*bs
,
1452 BdrvRequestFlags flags
)
1454 BlockDriverAIOCB
*blockacb
;
1455 BDRVQEDState
*s
= bs
->opaque
;
1456 QEDWriteZeroesCB cb
= { .done
= false };
1460 /* Refuse if there are untouched backing file sectors */
1461 if (bs
->backing_hd
) {
1462 if (qed_offset_into_cluster(s
, sector_num
* BDRV_SECTOR_SIZE
) != 0) {
1465 if (qed_offset_into_cluster(s
, nb_sectors
* BDRV_SECTOR_SIZE
) != 0) {
1470 /* Zero writes start without an I/O buffer. If a buffer becomes necessary
1471 * then it will be allocated during request processing.
1473 iov
.iov_base
= NULL
,
1474 iov
.iov_len
= nb_sectors
* BDRV_SECTOR_SIZE
,
1476 qemu_iovec_init_external(&qiov
, &iov
, 1);
1477 blockacb
= qed_aio_setup(bs
, sector_num
, &qiov
, nb_sectors
,
1478 qed_co_write_zeroes_cb
, &cb
,
1479 QED_AIOCB_WRITE
| QED_AIOCB_ZERO
);
1484 cb
.co
= qemu_coroutine_self();
1485 qemu_coroutine_yield();
1491 static int bdrv_qed_truncate(BlockDriverState
*bs
, int64_t offset
)
1493 BDRVQEDState
*s
= bs
->opaque
;
1494 uint64_t old_image_size
;
1497 if (!qed_is_image_size_valid(offset
, s
->header
.cluster_size
,
1498 s
->header
.table_size
)) {
1502 /* Shrinking is currently not supported */
1503 if ((uint64_t)offset
< s
->header
.image_size
) {
1507 old_image_size
= s
->header
.image_size
;
1508 s
->header
.image_size
= offset
;
1509 ret
= qed_write_header_sync(s
);
1511 s
->header
.image_size
= old_image_size
;
1516 static int64_t bdrv_qed_getlength(BlockDriverState
*bs
)
1518 BDRVQEDState
*s
= bs
->opaque
;
1519 return s
->header
.image_size
;
1522 static int bdrv_qed_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1524 BDRVQEDState
*s
= bs
->opaque
;
1526 memset(bdi
, 0, sizeof(*bdi
));
1527 bdi
->cluster_size
= s
->header
.cluster_size
;
1528 bdi
->is_dirty
= s
->header
.features
& QED_F_NEED_CHECK
;
1529 bdi
->unallocated_blocks_are_zero
= true;
1530 bdi
->can_write_zeroes_with_unmap
= true;
1534 static int bdrv_qed_change_backing_file(BlockDriverState
*bs
,
1535 const char *backing_file
,
1536 const char *backing_fmt
)
1538 BDRVQEDState
*s
= bs
->opaque
;
1539 QEDHeader new_header
, le_header
;
1541 size_t buffer_len
, backing_file_len
;
1544 /* Refuse to set backing filename if unknown compat feature bits are
1545 * active. If the image uses an unknown compat feature then we may not
1546 * know the layout of data following the header structure and cannot safely
1549 if (backing_file
&& (s
->header
.compat_features
&
1550 ~QED_COMPAT_FEATURE_MASK
)) {
1554 memcpy(&new_header
, &s
->header
, sizeof(new_header
));
1556 new_header
.features
&= ~(QED_F_BACKING_FILE
|
1557 QED_F_BACKING_FORMAT_NO_PROBE
);
1559 /* Adjust feature flags */
1561 new_header
.features
|= QED_F_BACKING_FILE
;
1563 if (qed_fmt_is_raw(backing_fmt
)) {
1564 new_header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
1568 /* Calculate new header size */
1569 backing_file_len
= 0;
1572 backing_file_len
= strlen(backing_file
);
1575 buffer_len
= sizeof(new_header
);
1576 new_header
.backing_filename_offset
= buffer_len
;
1577 new_header
.backing_filename_size
= backing_file_len
;
1578 buffer_len
+= backing_file_len
;
1580 /* Make sure we can rewrite header without failing */
1581 if (buffer_len
> new_header
.header_size
* new_header
.cluster_size
) {
1585 /* Prepare new header */
1586 buffer
= g_malloc(buffer_len
);
1588 qed_header_cpu_to_le(&new_header
, &le_header
);
1589 memcpy(buffer
, &le_header
, sizeof(le_header
));
1590 buffer_len
= sizeof(le_header
);
1593 memcpy(buffer
+ buffer_len
, backing_file
, backing_file_len
);
1594 buffer_len
+= backing_file_len
;
1597 /* Write new header */
1598 ret
= bdrv_pwrite_sync(bs
->file
, 0, buffer
, buffer_len
);
1601 memcpy(&s
->header
, &new_header
, sizeof(new_header
));
1606 static void bdrv_qed_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
1608 BDRVQEDState
*s
= bs
->opaque
;
1609 Error
*local_err
= NULL
;
1614 bdrv_invalidate_cache(bs
->file
, &local_err
);
1616 error_propagate(errp
, local_err
);
1620 memset(s
, 0, sizeof(BDRVQEDState
));
1621 ret
= bdrv_qed_open(bs
, NULL
, bs
->open_flags
, &local_err
);
1623 error_setg(errp
, "Could not reopen qed layer: %s",
1624 error_get_pretty(local_err
));
1625 error_free(local_err
);
1627 } else if (ret
< 0) {
1628 error_setg_errno(errp
, -ret
, "Could not reopen qed layer");
1633 static int bdrv_qed_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
1636 BDRVQEDState
*s
= bs
->opaque
;
1638 return qed_check(s
, result
, !!fix
);
1641 static QemuOptsList qed_create_opts
= {
1642 .name
= "qed-create-opts",
1643 .head
= QTAILQ_HEAD_INITIALIZER(qed_create_opts
.head
),
1646 .name
= BLOCK_OPT_SIZE
,
1647 .type
= QEMU_OPT_SIZE
,
1648 .help
= "Virtual disk size"
1651 .name
= BLOCK_OPT_BACKING_FILE
,
1652 .type
= QEMU_OPT_STRING
,
1653 .help
= "File name of a base image"
1656 .name
= BLOCK_OPT_BACKING_FMT
,
1657 .type
= QEMU_OPT_STRING
,
1658 .help
= "Image format of the base image"
1661 .name
= BLOCK_OPT_CLUSTER_SIZE
,
1662 .type
= QEMU_OPT_SIZE
,
1663 .help
= "Cluster size (in bytes)",
1664 .def_value_str
= stringify(QED_DEFAULT_CLUSTER_SIZE
)
1667 .name
= BLOCK_OPT_TABLE_SIZE
,
1668 .type
= QEMU_OPT_SIZE
,
1669 .help
= "L1/L2 table size (in clusters)"
1671 { /* end of list */ }
1675 static BlockDriver bdrv_qed
= {
1676 .format_name
= "qed",
1677 .instance_size
= sizeof(BDRVQEDState
),
1678 .create_opts
= &qed_create_opts
,
1679 .supports_backing
= true,
1681 .bdrv_probe
= bdrv_qed_probe
,
1682 .bdrv_rebind
= bdrv_qed_rebind
,
1683 .bdrv_open
= bdrv_qed_open
,
1684 .bdrv_close
= bdrv_qed_close
,
1685 .bdrv_reopen_prepare
= bdrv_qed_reopen_prepare
,
1686 .bdrv_create
= bdrv_qed_create
,
1687 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
1688 .bdrv_co_get_block_status
= bdrv_qed_co_get_block_status
,
1689 .bdrv_aio_readv
= bdrv_qed_aio_readv
,
1690 .bdrv_aio_writev
= bdrv_qed_aio_writev
,
1691 .bdrv_co_write_zeroes
= bdrv_qed_co_write_zeroes
,
1692 .bdrv_truncate
= bdrv_qed_truncate
,
1693 .bdrv_getlength
= bdrv_qed_getlength
,
1694 .bdrv_get_info
= bdrv_qed_get_info
,
1695 .bdrv_refresh_limits
= bdrv_qed_refresh_limits
,
1696 .bdrv_change_backing_file
= bdrv_qed_change_backing_file
,
1697 .bdrv_invalidate_cache
= bdrv_qed_invalidate_cache
,
1698 .bdrv_check
= bdrv_qed_check
,
1699 .bdrv_detach_aio_context
= bdrv_qed_detach_aio_context
,
1700 .bdrv_attach_aio_context
= bdrv_qed_attach_aio_context
,
1703 static void bdrv_qed_init(void)
1705 bdrv_register(&bdrv_qed
);
1708 block_init(bdrv_qed_init
);