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 int bdrv_qed_refresh_limits(BlockDriverState
*bs
)
533 BDRVQEDState
*s
= bs
->opaque
;
535 bs
->bl
.write_zeroes_alignment
= s
->header
.cluster_size
>> BDRV_SECTOR_BITS
;
540 /* We have nothing to do for QED reopen, stubs just return
542 static int bdrv_qed_reopen_prepare(BDRVReopenState
*state
,
543 BlockReopenQueue
*queue
, Error
**errp
)
548 static void bdrv_qed_close(BlockDriverState
*bs
)
550 BDRVQEDState
*s
= bs
->opaque
;
552 bdrv_qed_detach_aio_context(bs
);
554 /* Ensure writes reach stable storage */
555 bdrv_flush(bs
->file
);
557 /* Clean shutdown, no check required on next open */
558 if (s
->header
.features
& QED_F_NEED_CHECK
) {
559 s
->header
.features
&= ~QED_F_NEED_CHECK
;
560 qed_write_header_sync(s
);
563 qed_free_l2_cache(&s
->l2_cache
);
564 qemu_vfree(s
->l1_table
);
567 static int qed_create(const char *filename
, uint32_t cluster_size
,
568 uint64_t image_size
, uint32_t table_size
,
569 const char *backing_file
, const char *backing_fmt
,
570 QemuOpts
*opts
, Error
**errp
)
574 .cluster_size
= cluster_size
,
575 .table_size
= table_size
,
578 .compat_features
= 0,
579 .l1_table_offset
= cluster_size
,
580 .image_size
= image_size
,
583 uint8_t *l1_table
= NULL
;
584 size_t l1_size
= header
.cluster_size
* header
.table_size
;
585 Error
*local_err
= NULL
;
587 BlockDriverState
*bs
;
589 ret
= bdrv_create_file(filename
, opts
, &local_err
);
591 error_propagate(errp
, local_err
);
596 ret
= bdrv_open(&bs
, filename
, NULL
, NULL
,
597 BDRV_O_RDWR
| BDRV_O_CACHE_WB
| BDRV_O_PROTOCOL
, NULL
,
600 error_propagate(errp
, local_err
);
604 /* File must start empty and grow, check truncate is supported */
605 ret
= bdrv_truncate(bs
, 0);
611 header
.features
|= QED_F_BACKING_FILE
;
612 header
.backing_filename_offset
= sizeof(le_header
);
613 header
.backing_filename_size
= strlen(backing_file
);
615 if (qed_fmt_is_raw(backing_fmt
)) {
616 header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
620 qed_header_cpu_to_le(&header
, &le_header
);
621 ret
= bdrv_pwrite(bs
, 0, &le_header
, sizeof(le_header
));
625 ret
= bdrv_pwrite(bs
, sizeof(le_header
), backing_file
,
626 header
.backing_filename_size
);
631 l1_table
= g_malloc0(l1_size
);
632 ret
= bdrv_pwrite(bs
, header
.l1_table_offset
, l1_table
, l1_size
);
637 ret
= 0; /* success */
644 static int bdrv_qed_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
646 uint64_t image_size
= 0;
647 uint32_t cluster_size
= QED_DEFAULT_CLUSTER_SIZE
;
648 uint32_t table_size
= QED_DEFAULT_TABLE_SIZE
;
649 char *backing_file
= NULL
;
650 char *backing_fmt
= NULL
;
653 image_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0);
654 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
655 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
656 cluster_size
= qemu_opt_get_size_del(opts
,
657 BLOCK_OPT_CLUSTER_SIZE
,
658 QED_DEFAULT_CLUSTER_SIZE
);
659 table_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_TABLE_SIZE
,
660 QED_DEFAULT_TABLE_SIZE
);
662 if (!qed_is_cluster_size_valid(cluster_size
)) {
663 error_setg(errp
, "QED cluster size must be within range [%u, %u] "
665 QED_MIN_CLUSTER_SIZE
, QED_MAX_CLUSTER_SIZE
);
669 if (!qed_is_table_size_valid(table_size
)) {
670 error_setg(errp
, "QED table size must be within range [%u, %u] "
672 QED_MIN_TABLE_SIZE
, QED_MAX_TABLE_SIZE
);
676 if (!qed_is_image_size_valid(image_size
, cluster_size
, table_size
)) {
677 error_setg(errp
, "QED image size must be a non-zero multiple of "
678 "cluster size and less than %" PRIu64
" bytes",
679 qed_max_image_size(cluster_size
, table_size
));
684 ret
= qed_create(filename
, cluster_size
, image_size
, table_size
,
685 backing_file
, backing_fmt
, opts
, errp
);
688 g_free(backing_file
);
694 BlockDriverState
*bs
;
701 static void qed_is_allocated_cb(void *opaque
, int ret
, uint64_t offset
, size_t len
)
703 QEDIsAllocatedCB
*cb
= opaque
;
704 BDRVQEDState
*s
= cb
->bs
->opaque
;
705 *cb
->pnum
= len
/ BDRV_SECTOR_SIZE
;
707 case QED_CLUSTER_FOUND
:
708 offset
|= qed_offset_into_cluster(s
, cb
->pos
);
709 cb
->status
= BDRV_BLOCK_DATA
| BDRV_BLOCK_OFFSET_VALID
| offset
;
711 case QED_CLUSTER_ZERO
:
712 cb
->status
= BDRV_BLOCK_ZERO
;
725 qemu_coroutine_enter(cb
->co
, NULL
);
729 static int64_t coroutine_fn
bdrv_qed_co_get_block_status(BlockDriverState
*bs
,
731 int nb_sectors
, int *pnum
)
733 BDRVQEDState
*s
= bs
->opaque
;
734 size_t len
= (size_t)nb_sectors
* BDRV_SECTOR_SIZE
;
735 QEDIsAllocatedCB cb
= {
737 .pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
,
738 .status
= BDRV_BLOCK_OFFSET_MASK
,
741 QEDRequest request
= { .l2_table
= NULL
};
743 qed_find_cluster(s
, &request
, cb
.pos
, len
, qed_is_allocated_cb
, &cb
);
745 /* Now sleep if the callback wasn't invoked immediately */
746 while (cb
.status
== BDRV_BLOCK_OFFSET_MASK
) {
747 cb
.co
= qemu_coroutine_self();
748 qemu_coroutine_yield();
751 qed_unref_l2_cache_entry(request
.l2_table
);
756 static BDRVQEDState
*acb_to_s(QEDAIOCB
*acb
)
758 return acb
->common
.bs
->opaque
;
762 * Read from the backing file or zero-fill if no backing file
765 * @pos: Byte position in device
766 * @qiov: Destination I/O vector
767 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
768 * @cb: Completion function
769 * @opaque: User data for completion function
771 * This function reads qiov->size bytes starting at pos from the backing file.
772 * If there is no backing file then zeroes are read.
774 static void qed_read_backing_file(BDRVQEDState
*s
, uint64_t pos
,
776 QEMUIOVector
**backing_qiov
,
777 BlockDriverCompletionFunc
*cb
, void *opaque
)
779 uint64_t backing_length
= 0;
782 /* If there is a backing file, get its length. Treat the absence of a
783 * backing file like a zero length backing file.
785 if (s
->bs
->backing_hd
) {
786 int64_t l
= bdrv_getlength(s
->bs
->backing_hd
);
794 /* Zero all sectors if reading beyond the end of the backing file */
795 if (pos
>= backing_length
||
796 pos
+ qiov
->size
> backing_length
) {
797 qemu_iovec_memset(qiov
, 0, 0, qiov
->size
);
800 /* Complete now if there are no backing file sectors to read */
801 if (pos
>= backing_length
) {
806 /* If the read straddles the end of the backing file, shorten it */
807 size
= MIN((uint64_t)backing_length
- pos
, qiov
->size
);
809 assert(*backing_qiov
== NULL
);
810 *backing_qiov
= g_new(QEMUIOVector
, 1);
811 qemu_iovec_init(*backing_qiov
, qiov
->niov
);
812 qemu_iovec_concat(*backing_qiov
, qiov
, 0, size
);
814 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_READ_BACKING_AIO
);
815 bdrv_aio_readv(s
->bs
->backing_hd
, pos
/ BDRV_SECTOR_SIZE
,
816 *backing_qiov
, size
/ BDRV_SECTOR_SIZE
, cb
, opaque
);
823 QEMUIOVector
*backing_qiov
;
826 } CopyFromBackingFileCB
;
828 static void qed_copy_from_backing_file_cb(void *opaque
, int ret
)
830 CopyFromBackingFileCB
*copy_cb
= opaque
;
831 qemu_vfree(copy_cb
->iov
.iov_base
);
832 gencb_complete(©_cb
->gencb
, ret
);
835 static void qed_copy_from_backing_file_write(void *opaque
, int ret
)
837 CopyFromBackingFileCB
*copy_cb
= opaque
;
838 BDRVQEDState
*s
= copy_cb
->s
;
840 if (copy_cb
->backing_qiov
) {
841 qemu_iovec_destroy(copy_cb
->backing_qiov
);
842 g_free(copy_cb
->backing_qiov
);
843 copy_cb
->backing_qiov
= NULL
;
847 qed_copy_from_backing_file_cb(copy_cb
, ret
);
851 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_COW_WRITE
);
852 bdrv_aio_writev(s
->bs
->file
, copy_cb
->offset
/ BDRV_SECTOR_SIZE
,
853 ©_cb
->qiov
, copy_cb
->qiov
.size
/ BDRV_SECTOR_SIZE
,
854 qed_copy_from_backing_file_cb
, copy_cb
);
858 * Copy data from backing file into the image
861 * @pos: Byte position in device
862 * @len: Number of bytes
863 * @offset: Byte offset in image file
864 * @cb: Completion function
865 * @opaque: User data for completion function
867 static void qed_copy_from_backing_file(BDRVQEDState
*s
, uint64_t pos
,
868 uint64_t len
, uint64_t offset
,
869 BlockDriverCompletionFunc
*cb
,
872 CopyFromBackingFileCB
*copy_cb
;
874 /* Skip copy entirely if there is no work to do */
880 copy_cb
= gencb_alloc(sizeof(*copy_cb
), cb
, opaque
);
882 copy_cb
->offset
= offset
;
883 copy_cb
->backing_qiov
= NULL
;
884 copy_cb
->iov
.iov_base
= qemu_blockalign(s
->bs
, len
);
885 copy_cb
->iov
.iov_len
= len
;
886 qemu_iovec_init_external(©_cb
->qiov
, ©_cb
->iov
, 1);
888 qed_read_backing_file(s
, pos
, ©_cb
->qiov
, ©_cb
->backing_qiov
,
889 qed_copy_from_backing_file_write
, copy_cb
);
893 * Link one or more contiguous clusters into a table
897 * @index: First cluster index
898 * @n: Number of contiguous clusters
899 * @cluster: First cluster offset
901 * The cluster offset may be an allocated byte offset in the image file, the
902 * zero cluster marker, or the unallocated cluster marker.
904 static void qed_update_l2_table(BDRVQEDState
*s
, QEDTable
*table
, int index
,
905 unsigned int n
, uint64_t cluster
)
908 for (i
= index
; i
< index
+ n
; i
++) {
909 table
->offsets
[i
] = cluster
;
910 if (!qed_offset_is_unalloc_cluster(cluster
) &&
911 !qed_offset_is_zero_cluster(cluster
)) {
912 cluster
+= s
->header
.cluster_size
;
917 static void qed_aio_complete_bh(void *opaque
)
919 QEDAIOCB
*acb
= opaque
;
920 BlockDriverCompletionFunc
*cb
= acb
->common
.cb
;
921 void *user_opaque
= acb
->common
.opaque
;
922 int ret
= acb
->bh_ret
;
923 bool *finished
= acb
->finished
;
925 qemu_bh_delete(acb
->bh
);
926 qemu_aio_release(acb
);
928 /* Invoke callback */
929 cb(user_opaque
, ret
);
931 /* Signal cancel completion */
937 static void qed_aio_complete(QEDAIOCB
*acb
, int ret
)
939 BDRVQEDState
*s
= acb_to_s(acb
);
941 trace_qed_aio_complete(s
, acb
, ret
);
944 qemu_iovec_destroy(&acb
->cur_qiov
);
945 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
947 /* Free the buffer we may have allocated for zero writes */
948 if (acb
->flags
& QED_AIOCB_ZERO
) {
949 qemu_vfree(acb
->qiov
->iov
[0].iov_base
);
950 acb
->qiov
->iov
[0].iov_base
= NULL
;
953 /* Arrange for a bh to invoke the completion function */
955 acb
->bh
= aio_bh_new(bdrv_get_aio_context(acb
->common
.bs
),
956 qed_aio_complete_bh
, acb
);
957 qemu_bh_schedule(acb
->bh
);
959 /* Start next allocating write request waiting behind this one. Note that
960 * requests enqueue themselves when they first hit an unallocated cluster
961 * but they wait until the entire request is finished before waking up the
962 * next request in the queue. This ensures that we don't cycle through
963 * requests multiple times but rather finish one at a time completely.
965 if (acb
== QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
966 QSIMPLEQ_REMOVE_HEAD(&s
->allocating_write_reqs
, next
);
967 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
969 qed_aio_next_io(acb
, 0);
970 } else if (s
->header
.features
& QED_F_NEED_CHECK
) {
971 qed_start_need_check_timer(s
);
977 * Commit the current L2 table to the cache
979 static void qed_commit_l2_update(void *opaque
, int ret
)
981 QEDAIOCB
*acb
= opaque
;
982 BDRVQEDState
*s
= acb_to_s(acb
);
983 CachedL2Table
*l2_table
= acb
->request
.l2_table
;
984 uint64_t l2_offset
= l2_table
->offset
;
986 qed_commit_l2_cache_entry(&s
->l2_cache
, l2_table
);
988 /* This is guaranteed to succeed because we just committed the entry to the
991 acb
->request
.l2_table
= qed_find_l2_cache_entry(&s
->l2_cache
, l2_offset
);
992 assert(acb
->request
.l2_table
!= NULL
);
994 qed_aio_next_io(opaque
, ret
);
998 * Update L1 table with new L2 table offset and write it out
1000 static void qed_aio_write_l1_update(void *opaque
, int ret
)
1002 QEDAIOCB
*acb
= opaque
;
1003 BDRVQEDState
*s
= acb_to_s(acb
);
1007 qed_aio_complete(acb
, ret
);
1011 index
= qed_l1_index(s
, acb
->cur_pos
);
1012 s
->l1_table
->offsets
[index
] = acb
->request
.l2_table
->offset
;
1014 qed_write_l1_table(s
, index
, 1, qed_commit_l2_update
, acb
);
1018 * Update L2 table with new cluster offsets and write them out
1020 static void qed_aio_write_l2_update(QEDAIOCB
*acb
, int ret
, uint64_t offset
)
1022 BDRVQEDState
*s
= acb_to_s(acb
);
1023 bool need_alloc
= acb
->find_cluster_ret
== QED_CLUSTER_L1
;
1031 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
1032 acb
->request
.l2_table
= qed_new_l2_table(s
);
1035 index
= qed_l2_index(s
, acb
->cur_pos
);
1036 qed_update_l2_table(s
, acb
->request
.l2_table
->table
, index
, acb
->cur_nclusters
,
1040 /* Write out the whole new L2 table */
1041 qed_write_l2_table(s
, &acb
->request
, 0, s
->table_nelems
, true,
1042 qed_aio_write_l1_update
, acb
);
1044 /* Write out only the updated part of the L2 table */
1045 qed_write_l2_table(s
, &acb
->request
, index
, acb
->cur_nclusters
, false,
1046 qed_aio_next_io
, acb
);
1051 qed_aio_complete(acb
, ret
);
1054 static void qed_aio_write_l2_update_cb(void *opaque
, int ret
)
1056 QEDAIOCB
*acb
= opaque
;
1057 qed_aio_write_l2_update(acb
, ret
, acb
->cur_cluster
);
1061 * Flush new data clusters before updating the L2 table
1063 * This flush is necessary when a backing file is in use. A crash during an
1064 * allocating write could result in empty clusters in the image. If the write
1065 * only touched a subregion of the cluster, then backing image sectors have
1066 * been lost in the untouched region. The solution is to flush after writing a
1067 * new data cluster and before updating the L2 table.
1069 static void qed_aio_write_flush_before_l2_update(void *opaque
, int ret
)
1071 QEDAIOCB
*acb
= opaque
;
1072 BDRVQEDState
*s
= acb_to_s(acb
);
1074 if (!bdrv_aio_flush(s
->bs
->file
, qed_aio_write_l2_update_cb
, opaque
)) {
1075 qed_aio_complete(acb
, -EIO
);
1080 * Write data to the image file
1082 static void qed_aio_write_main(void *opaque
, int ret
)
1084 QEDAIOCB
*acb
= opaque
;
1085 BDRVQEDState
*s
= acb_to_s(acb
);
1086 uint64_t offset
= acb
->cur_cluster
+
1087 qed_offset_into_cluster(s
, acb
->cur_pos
);
1088 BlockDriverCompletionFunc
*next_fn
;
1090 trace_qed_aio_write_main(s
, acb
, ret
, offset
, acb
->cur_qiov
.size
);
1093 qed_aio_complete(acb
, ret
);
1097 if (acb
->find_cluster_ret
== QED_CLUSTER_FOUND
) {
1098 next_fn
= qed_aio_next_io
;
1100 if (s
->bs
->backing_hd
) {
1101 next_fn
= qed_aio_write_flush_before_l2_update
;
1103 next_fn
= qed_aio_write_l2_update_cb
;
1107 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_WRITE_AIO
);
1108 bdrv_aio_writev(s
->bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1109 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1114 * Populate back untouched region of new data cluster
1116 static void qed_aio_write_postfill(void *opaque
, int ret
)
1118 QEDAIOCB
*acb
= opaque
;
1119 BDRVQEDState
*s
= acb_to_s(acb
);
1120 uint64_t start
= acb
->cur_pos
+ acb
->cur_qiov
.size
;
1122 qed_start_of_cluster(s
, start
+ s
->header
.cluster_size
- 1) - start
;
1123 uint64_t offset
= acb
->cur_cluster
+
1124 qed_offset_into_cluster(s
, acb
->cur_pos
) +
1128 qed_aio_complete(acb
, ret
);
1132 trace_qed_aio_write_postfill(s
, acb
, start
, len
, offset
);
1133 qed_copy_from_backing_file(s
, start
, len
, offset
,
1134 qed_aio_write_main
, acb
);
1138 * Populate front untouched region of new data cluster
1140 static void qed_aio_write_prefill(void *opaque
, int ret
)
1142 QEDAIOCB
*acb
= opaque
;
1143 BDRVQEDState
*s
= acb_to_s(acb
);
1144 uint64_t start
= qed_start_of_cluster(s
, acb
->cur_pos
);
1145 uint64_t len
= qed_offset_into_cluster(s
, acb
->cur_pos
);
1147 trace_qed_aio_write_prefill(s
, acb
, start
, len
, acb
->cur_cluster
);
1148 qed_copy_from_backing_file(s
, start
, len
, acb
->cur_cluster
,
1149 qed_aio_write_postfill
, acb
);
1153 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1155 static bool qed_should_set_need_check(BDRVQEDState
*s
)
1157 /* The flush before L2 update path ensures consistency */
1158 if (s
->bs
->backing_hd
) {
1162 return !(s
->header
.features
& QED_F_NEED_CHECK
);
1165 static void qed_aio_write_zero_cluster(void *opaque
, int ret
)
1167 QEDAIOCB
*acb
= opaque
;
1170 qed_aio_complete(acb
, ret
);
1174 qed_aio_write_l2_update(acb
, 0, 1);
1178 * Write new data cluster
1180 * @acb: Write request
1181 * @len: Length in bytes
1183 * This path is taken when writing to previously unallocated clusters.
1185 static void qed_aio_write_alloc(QEDAIOCB
*acb
, size_t len
)
1187 BDRVQEDState
*s
= acb_to_s(acb
);
1188 BlockDriverCompletionFunc
*cb
;
1190 /* Cancel timer when the first allocating request comes in */
1191 if (QSIMPLEQ_EMPTY(&s
->allocating_write_reqs
)) {
1192 qed_cancel_need_check_timer(s
);
1195 /* Freeze this request if another allocating write is in progress */
1196 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
1197 QSIMPLEQ_INSERT_TAIL(&s
->allocating_write_reqs
, acb
, next
);
1199 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
) ||
1200 s
->allocating_write_reqs_plugged
) {
1201 return; /* wait for existing request to finish */
1204 acb
->cur_nclusters
= qed_bytes_to_clusters(s
,
1205 qed_offset_into_cluster(s
, acb
->cur_pos
) + len
);
1206 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1208 if (acb
->flags
& QED_AIOCB_ZERO
) {
1209 /* Skip ahead if the clusters are already zero */
1210 if (acb
->find_cluster_ret
== QED_CLUSTER_ZERO
) {
1211 qed_aio_next_io(acb
, 0);
1215 cb
= qed_aio_write_zero_cluster
;
1217 cb
= qed_aio_write_prefill
;
1218 acb
->cur_cluster
= qed_alloc_clusters(s
, acb
->cur_nclusters
);
1221 if (qed_should_set_need_check(s
)) {
1222 s
->header
.features
|= QED_F_NEED_CHECK
;
1223 qed_write_header(s
, cb
, acb
);
1230 * Write data cluster in place
1232 * @acb: Write request
1233 * @offset: Cluster offset in bytes
1234 * @len: Length in bytes
1236 * This path is taken when writing to already allocated clusters.
1238 static void qed_aio_write_inplace(QEDAIOCB
*acb
, uint64_t offset
, size_t len
)
1240 /* Allocate buffer for zero writes */
1241 if (acb
->flags
& QED_AIOCB_ZERO
) {
1242 struct iovec
*iov
= acb
->qiov
->iov
;
1244 if (!iov
->iov_base
) {
1245 iov
->iov_base
= qemu_blockalign(acb
->common
.bs
, iov
->iov_len
);
1246 memset(iov
->iov_base
, 0, iov
->iov_len
);
1250 /* Calculate the I/O vector */
1251 acb
->cur_cluster
= offset
;
1252 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1254 /* Do the actual write */
1255 qed_aio_write_main(acb
, 0);
1259 * Write data cluster
1261 * @opaque: Write request
1262 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1264 * @offset: Cluster offset in bytes
1265 * @len: Length in bytes
1267 * Callback from qed_find_cluster().
1269 static void qed_aio_write_data(void *opaque
, int ret
,
1270 uint64_t offset
, size_t len
)
1272 QEDAIOCB
*acb
= opaque
;
1274 trace_qed_aio_write_data(acb_to_s(acb
), acb
, ret
, offset
, len
);
1276 acb
->find_cluster_ret
= ret
;
1279 case QED_CLUSTER_FOUND
:
1280 qed_aio_write_inplace(acb
, offset
, len
);
1283 case QED_CLUSTER_L2
:
1284 case QED_CLUSTER_L1
:
1285 case QED_CLUSTER_ZERO
:
1286 qed_aio_write_alloc(acb
, len
);
1290 qed_aio_complete(acb
, ret
);
1298 * @opaque: Read request
1299 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1301 * @offset: Cluster offset in bytes
1302 * @len: Length in bytes
1304 * Callback from qed_find_cluster().
1306 static void qed_aio_read_data(void *opaque
, int ret
,
1307 uint64_t offset
, size_t len
)
1309 QEDAIOCB
*acb
= opaque
;
1310 BDRVQEDState
*s
= acb_to_s(acb
);
1311 BlockDriverState
*bs
= acb
->common
.bs
;
1313 /* Adjust offset into cluster */
1314 offset
+= qed_offset_into_cluster(s
, acb
->cur_pos
);
1316 trace_qed_aio_read_data(s
, acb
, ret
, offset
, len
);
1322 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1324 /* Handle zero cluster and backing file reads */
1325 if (ret
== QED_CLUSTER_ZERO
) {
1326 qemu_iovec_memset(&acb
->cur_qiov
, 0, 0, acb
->cur_qiov
.size
);
1327 qed_aio_next_io(acb
, 0);
1329 } else if (ret
!= QED_CLUSTER_FOUND
) {
1330 qed_read_backing_file(s
, acb
->cur_pos
, &acb
->cur_qiov
,
1331 &acb
->backing_qiov
, qed_aio_next_io
, acb
);
1335 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1336 bdrv_aio_readv(bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1337 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1338 qed_aio_next_io
, acb
);
1342 qed_aio_complete(acb
, ret
);
1346 * Begin next I/O or complete the request
1348 static void qed_aio_next_io(void *opaque
, int ret
)
1350 QEDAIOCB
*acb
= opaque
;
1351 BDRVQEDState
*s
= acb_to_s(acb
);
1352 QEDFindClusterFunc
*io_fn
= (acb
->flags
& QED_AIOCB_WRITE
) ?
1353 qed_aio_write_data
: qed_aio_read_data
;
1355 trace_qed_aio_next_io(s
, acb
, ret
, acb
->cur_pos
+ acb
->cur_qiov
.size
);
1357 if (acb
->backing_qiov
) {
1358 qemu_iovec_destroy(acb
->backing_qiov
);
1359 g_free(acb
->backing_qiov
);
1360 acb
->backing_qiov
= NULL
;
1363 /* Handle I/O error */
1365 qed_aio_complete(acb
, ret
);
1369 acb
->qiov_offset
+= acb
->cur_qiov
.size
;
1370 acb
->cur_pos
+= acb
->cur_qiov
.size
;
1371 qemu_iovec_reset(&acb
->cur_qiov
);
1373 /* Complete request */
1374 if (acb
->cur_pos
>= acb
->end_pos
) {
1375 qed_aio_complete(acb
, 0);
1379 /* Find next cluster and start I/O */
1380 qed_find_cluster(s
, &acb
->request
,
1381 acb
->cur_pos
, acb
->end_pos
- acb
->cur_pos
,
1385 static BlockDriverAIOCB
*qed_aio_setup(BlockDriverState
*bs
,
1387 QEMUIOVector
*qiov
, int nb_sectors
,
1388 BlockDriverCompletionFunc
*cb
,
1389 void *opaque
, int flags
)
1391 QEDAIOCB
*acb
= qemu_aio_get(&qed_aiocb_info
, bs
, cb
, opaque
);
1393 trace_qed_aio_setup(bs
->opaque
, acb
, sector_num
, nb_sectors
,
1397 acb
->finished
= NULL
;
1399 acb
->qiov_offset
= 0;
1400 acb
->cur_pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
;
1401 acb
->end_pos
= acb
->cur_pos
+ nb_sectors
* BDRV_SECTOR_SIZE
;
1402 acb
->backing_qiov
= NULL
;
1403 acb
->request
.l2_table
= NULL
;
1404 qemu_iovec_init(&acb
->cur_qiov
, qiov
->niov
);
1407 qed_aio_next_io(acb
, 0);
1408 return &acb
->common
;
1411 static BlockDriverAIOCB
*bdrv_qed_aio_readv(BlockDriverState
*bs
,
1413 QEMUIOVector
*qiov
, int nb_sectors
,
1414 BlockDriverCompletionFunc
*cb
,
1417 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
, opaque
, 0);
1420 static BlockDriverAIOCB
*bdrv_qed_aio_writev(BlockDriverState
*bs
,
1422 QEMUIOVector
*qiov
, int nb_sectors
,
1423 BlockDriverCompletionFunc
*cb
,
1426 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
,
1427 opaque
, QED_AIOCB_WRITE
);
1436 static void coroutine_fn
qed_co_write_zeroes_cb(void *opaque
, int ret
)
1438 QEDWriteZeroesCB
*cb
= opaque
;
1443 qemu_coroutine_enter(cb
->co
, NULL
);
1447 static int coroutine_fn
bdrv_qed_co_write_zeroes(BlockDriverState
*bs
,
1450 BdrvRequestFlags flags
)
1452 BlockDriverAIOCB
*blockacb
;
1453 BDRVQEDState
*s
= bs
->opaque
;
1454 QEDWriteZeroesCB cb
= { .done
= false };
1458 /* Refuse if there are untouched backing file sectors */
1459 if (bs
->backing_hd
) {
1460 if (qed_offset_into_cluster(s
, sector_num
* BDRV_SECTOR_SIZE
) != 0) {
1463 if (qed_offset_into_cluster(s
, nb_sectors
* BDRV_SECTOR_SIZE
) != 0) {
1468 /* Zero writes start without an I/O buffer. If a buffer becomes necessary
1469 * then it will be allocated during request processing.
1471 iov
.iov_base
= NULL
,
1472 iov
.iov_len
= nb_sectors
* BDRV_SECTOR_SIZE
,
1474 qemu_iovec_init_external(&qiov
, &iov
, 1);
1475 blockacb
= qed_aio_setup(bs
, sector_num
, &qiov
, nb_sectors
,
1476 qed_co_write_zeroes_cb
, &cb
,
1477 QED_AIOCB_WRITE
| QED_AIOCB_ZERO
);
1482 cb
.co
= qemu_coroutine_self();
1483 qemu_coroutine_yield();
1489 static int bdrv_qed_truncate(BlockDriverState
*bs
, int64_t offset
)
1491 BDRVQEDState
*s
= bs
->opaque
;
1492 uint64_t old_image_size
;
1495 if (!qed_is_image_size_valid(offset
, s
->header
.cluster_size
,
1496 s
->header
.table_size
)) {
1500 /* Shrinking is currently not supported */
1501 if ((uint64_t)offset
< s
->header
.image_size
) {
1505 old_image_size
= s
->header
.image_size
;
1506 s
->header
.image_size
= offset
;
1507 ret
= qed_write_header_sync(s
);
1509 s
->header
.image_size
= old_image_size
;
1514 static int64_t bdrv_qed_getlength(BlockDriverState
*bs
)
1516 BDRVQEDState
*s
= bs
->opaque
;
1517 return s
->header
.image_size
;
1520 static int bdrv_qed_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1522 BDRVQEDState
*s
= bs
->opaque
;
1524 memset(bdi
, 0, sizeof(*bdi
));
1525 bdi
->cluster_size
= s
->header
.cluster_size
;
1526 bdi
->is_dirty
= s
->header
.features
& QED_F_NEED_CHECK
;
1527 bdi
->unallocated_blocks_are_zero
= true;
1528 bdi
->can_write_zeroes_with_unmap
= true;
1532 static int bdrv_qed_change_backing_file(BlockDriverState
*bs
,
1533 const char *backing_file
,
1534 const char *backing_fmt
)
1536 BDRVQEDState
*s
= bs
->opaque
;
1537 QEDHeader new_header
, le_header
;
1539 size_t buffer_len
, backing_file_len
;
1542 /* Refuse to set backing filename if unknown compat feature bits are
1543 * active. If the image uses an unknown compat feature then we may not
1544 * know the layout of data following the header structure and cannot safely
1547 if (backing_file
&& (s
->header
.compat_features
&
1548 ~QED_COMPAT_FEATURE_MASK
)) {
1552 memcpy(&new_header
, &s
->header
, sizeof(new_header
));
1554 new_header
.features
&= ~(QED_F_BACKING_FILE
|
1555 QED_F_BACKING_FORMAT_NO_PROBE
);
1557 /* Adjust feature flags */
1559 new_header
.features
|= QED_F_BACKING_FILE
;
1561 if (qed_fmt_is_raw(backing_fmt
)) {
1562 new_header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
1566 /* Calculate new header size */
1567 backing_file_len
= 0;
1570 backing_file_len
= strlen(backing_file
);
1573 buffer_len
= sizeof(new_header
);
1574 new_header
.backing_filename_offset
= buffer_len
;
1575 new_header
.backing_filename_size
= backing_file_len
;
1576 buffer_len
+= backing_file_len
;
1578 /* Make sure we can rewrite header without failing */
1579 if (buffer_len
> new_header
.header_size
* new_header
.cluster_size
) {
1583 /* Prepare new header */
1584 buffer
= g_malloc(buffer_len
);
1586 qed_header_cpu_to_le(&new_header
, &le_header
);
1587 memcpy(buffer
, &le_header
, sizeof(le_header
));
1588 buffer_len
= sizeof(le_header
);
1591 memcpy(buffer
+ buffer_len
, backing_file
, backing_file_len
);
1592 buffer_len
+= backing_file_len
;
1595 /* Write new header */
1596 ret
= bdrv_pwrite_sync(bs
->file
, 0, buffer
, buffer_len
);
1599 memcpy(&s
->header
, &new_header
, sizeof(new_header
));
1604 static void bdrv_qed_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
1606 BDRVQEDState
*s
= bs
->opaque
;
1607 Error
*local_err
= NULL
;
1612 bdrv_invalidate_cache(bs
->file
, &local_err
);
1614 error_propagate(errp
, local_err
);
1618 memset(s
, 0, sizeof(BDRVQEDState
));
1619 ret
= bdrv_qed_open(bs
, NULL
, bs
->open_flags
, &local_err
);
1621 error_setg(errp
, "Could not reopen qed layer: %s",
1622 error_get_pretty(local_err
));
1623 error_free(local_err
);
1625 } else if (ret
< 0) {
1626 error_setg_errno(errp
, -ret
, "Could not reopen qed layer");
1631 static int bdrv_qed_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
1634 BDRVQEDState
*s
= bs
->opaque
;
1636 return qed_check(s
, result
, !!fix
);
1639 static QemuOptsList qed_create_opts
= {
1640 .name
= "qed-create-opts",
1641 .head
= QTAILQ_HEAD_INITIALIZER(qed_create_opts
.head
),
1644 .name
= BLOCK_OPT_SIZE
,
1645 .type
= QEMU_OPT_SIZE
,
1646 .help
= "Virtual disk size"
1649 .name
= BLOCK_OPT_BACKING_FILE
,
1650 .type
= QEMU_OPT_STRING
,
1651 .help
= "File name of a base image"
1654 .name
= BLOCK_OPT_BACKING_FMT
,
1655 .type
= QEMU_OPT_STRING
,
1656 .help
= "Image format of the base image"
1659 .name
= BLOCK_OPT_CLUSTER_SIZE
,
1660 .type
= QEMU_OPT_SIZE
,
1661 .help
= "Cluster size (in bytes)",
1662 .def_value_str
= stringify(QED_DEFAULT_CLUSTER_SIZE
)
1665 .name
= BLOCK_OPT_TABLE_SIZE
,
1666 .type
= QEMU_OPT_SIZE
,
1667 .help
= "L1/L2 table size (in clusters)"
1669 { /* end of list */ }
1673 static BlockDriver bdrv_qed
= {
1674 .format_name
= "qed",
1675 .instance_size
= sizeof(BDRVQEDState
),
1676 .create_opts
= &qed_create_opts
,
1677 .supports_backing
= true,
1679 .bdrv_probe
= bdrv_qed_probe
,
1680 .bdrv_rebind
= bdrv_qed_rebind
,
1681 .bdrv_open
= bdrv_qed_open
,
1682 .bdrv_close
= bdrv_qed_close
,
1683 .bdrv_reopen_prepare
= bdrv_qed_reopen_prepare
,
1684 .bdrv_create
= bdrv_qed_create
,
1685 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
1686 .bdrv_co_get_block_status
= bdrv_qed_co_get_block_status
,
1687 .bdrv_aio_readv
= bdrv_qed_aio_readv
,
1688 .bdrv_aio_writev
= bdrv_qed_aio_writev
,
1689 .bdrv_co_write_zeroes
= bdrv_qed_co_write_zeroes
,
1690 .bdrv_truncate
= bdrv_qed_truncate
,
1691 .bdrv_getlength
= bdrv_qed_getlength
,
1692 .bdrv_get_info
= bdrv_qed_get_info
,
1693 .bdrv_refresh_limits
= bdrv_qed_refresh_limits
,
1694 .bdrv_change_backing_file
= bdrv_qed_change_backing_file
,
1695 .bdrv_invalidate_cache
= bdrv_qed_invalidate_cache
,
1696 .bdrv_check
= bdrv_qed_check
,
1697 .bdrv_detach_aio_context
= bdrv_qed_detach_aio_context
,
1698 .bdrv_attach_aio_context
= bdrv_qed_attach_aio_context
,
1701 static void bdrv_qed_init(void)
1703 bdrv_register(&bdrv_qed
);
1706 block_init(bdrv_qed_init
);