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/osdep.h"
16 #include "qemu/timer.h"
19 #include "qapi/qmp/qerror.h"
20 #include "migration/migration.h"
21 #include "sysemu/block-backend.h"
23 static const AIOCBInfo qed_aiocb_info
= {
24 .aiocb_size
= sizeof(QEDAIOCB
),
27 static int bdrv_qed_probe(const uint8_t *buf
, int buf_size
,
30 const QEDHeader
*header
= (const QEDHeader
*)buf
;
32 if (buf_size
< sizeof(*header
)) {
35 if (le32_to_cpu(header
->magic
) != QED_MAGIC
) {
42 * Check whether an image format is raw
44 * @fmt: Backing file format, may be NULL
46 static bool qed_fmt_is_raw(const char *fmt
)
48 return fmt
&& strcmp(fmt
, "raw") == 0;
51 static void qed_header_le_to_cpu(const QEDHeader
*le
, QEDHeader
*cpu
)
53 cpu
->magic
= le32_to_cpu(le
->magic
);
54 cpu
->cluster_size
= le32_to_cpu(le
->cluster_size
);
55 cpu
->table_size
= le32_to_cpu(le
->table_size
);
56 cpu
->header_size
= le32_to_cpu(le
->header_size
);
57 cpu
->features
= le64_to_cpu(le
->features
);
58 cpu
->compat_features
= le64_to_cpu(le
->compat_features
);
59 cpu
->autoclear_features
= le64_to_cpu(le
->autoclear_features
);
60 cpu
->l1_table_offset
= le64_to_cpu(le
->l1_table_offset
);
61 cpu
->image_size
= le64_to_cpu(le
->image_size
);
62 cpu
->backing_filename_offset
= le32_to_cpu(le
->backing_filename_offset
);
63 cpu
->backing_filename_size
= le32_to_cpu(le
->backing_filename_size
);
66 static void qed_header_cpu_to_le(const QEDHeader
*cpu
, QEDHeader
*le
)
68 le
->magic
= cpu_to_le32(cpu
->magic
);
69 le
->cluster_size
= cpu_to_le32(cpu
->cluster_size
);
70 le
->table_size
= cpu_to_le32(cpu
->table_size
);
71 le
->header_size
= cpu_to_le32(cpu
->header_size
);
72 le
->features
= cpu_to_le64(cpu
->features
);
73 le
->compat_features
= cpu_to_le64(cpu
->compat_features
);
74 le
->autoclear_features
= cpu_to_le64(cpu
->autoclear_features
);
75 le
->l1_table_offset
= cpu_to_le64(cpu
->l1_table_offset
);
76 le
->image_size
= cpu_to_le64(cpu
->image_size
);
77 le
->backing_filename_offset
= cpu_to_le32(cpu
->backing_filename_offset
);
78 le
->backing_filename_size
= cpu_to_le32(cpu
->backing_filename_size
);
81 int qed_write_header_sync(BDRVQEDState
*s
)
86 qed_header_cpu_to_le(&s
->header
, &le
);
87 ret
= bdrv_pwrite(s
->bs
->file
->bs
, 0, &le
, sizeof(le
));
88 if (ret
!= sizeof(le
)) {
103 static void qed_write_header_cb(void *opaque
, int ret
)
105 QEDWriteHeaderCB
*write_header_cb
= opaque
;
107 qemu_vfree(write_header_cb
->buf
);
108 gencb_complete(write_header_cb
, ret
);
111 static void qed_write_header_read_cb(void *opaque
, int ret
)
113 QEDWriteHeaderCB
*write_header_cb
= opaque
;
114 BDRVQEDState
*s
= write_header_cb
->s
;
117 qed_write_header_cb(write_header_cb
, ret
);
122 qed_header_cpu_to_le(&s
->header
, (QEDHeader
*)write_header_cb
->buf
);
124 bdrv_aio_writev(s
->bs
->file
->bs
, 0, &write_header_cb
->qiov
,
125 write_header_cb
->nsectors
, qed_write_header_cb
,
130 * Update header in-place (does not rewrite backing filename or other strings)
132 * This function only updates known header fields in-place and does not affect
133 * extra data after the QED header.
135 static void qed_write_header(BDRVQEDState
*s
, BlockCompletionFunc cb
,
138 /* We must write full sectors for O_DIRECT but cannot necessarily generate
139 * the data following the header if an unrecognized compat feature is
140 * active. Therefore, first read the sectors containing the header, update
141 * them, and write back.
144 int nsectors
= (sizeof(QEDHeader
) + BDRV_SECTOR_SIZE
- 1) /
146 size_t len
= nsectors
* BDRV_SECTOR_SIZE
;
147 QEDWriteHeaderCB
*write_header_cb
= gencb_alloc(sizeof(*write_header_cb
),
150 write_header_cb
->s
= s
;
151 write_header_cb
->nsectors
= nsectors
;
152 write_header_cb
->buf
= qemu_blockalign(s
->bs
, len
);
153 write_header_cb
->iov
.iov_base
= write_header_cb
->buf
;
154 write_header_cb
->iov
.iov_len
= len
;
155 qemu_iovec_init_external(&write_header_cb
->qiov
, &write_header_cb
->iov
, 1);
157 bdrv_aio_readv(s
->bs
->file
->bs
, 0, &write_header_cb
->qiov
, nsectors
,
158 qed_write_header_read_cb
, write_header_cb
);
161 static uint64_t qed_max_image_size(uint32_t cluster_size
, uint32_t table_size
)
163 uint64_t table_entries
;
166 table_entries
= (table_size
* cluster_size
) / sizeof(uint64_t);
167 l2_size
= table_entries
* cluster_size
;
169 return l2_size
* table_entries
;
172 static bool qed_is_cluster_size_valid(uint32_t cluster_size
)
174 if (cluster_size
< QED_MIN_CLUSTER_SIZE
||
175 cluster_size
> QED_MAX_CLUSTER_SIZE
) {
178 if (cluster_size
& (cluster_size
- 1)) {
179 return false; /* not power of 2 */
184 static bool qed_is_table_size_valid(uint32_t table_size
)
186 if (table_size
< QED_MIN_TABLE_SIZE
||
187 table_size
> QED_MAX_TABLE_SIZE
) {
190 if (table_size
& (table_size
- 1)) {
191 return false; /* not power of 2 */
196 static bool qed_is_image_size_valid(uint64_t image_size
, uint32_t cluster_size
,
199 if (image_size
% BDRV_SECTOR_SIZE
!= 0) {
200 return false; /* not multiple of sector size */
202 if (image_size
> qed_max_image_size(cluster_size
, table_size
)) {
203 return false; /* image is too large */
209 * Read a string of known length from the image file
212 * @offset: File offset to start of string, in bytes
213 * @n: String length in bytes
214 * @buf: Destination buffer
215 * @buflen: Destination buffer length in bytes
216 * @ret: 0 on success, -errno on failure
218 * The string is NUL-terminated.
220 static int qed_read_string(BlockDriverState
*file
, uint64_t offset
, size_t n
,
221 char *buf
, size_t buflen
)
227 ret
= bdrv_pread(file
, offset
, buf
, n
);
236 * Allocate new clusters
239 * @n: Number of contiguous clusters to allocate
240 * @ret: Offset of first allocated cluster
242 * This function only produces the offset where the new clusters should be
243 * written. It updates BDRVQEDState but does not make any changes to the image
246 static uint64_t qed_alloc_clusters(BDRVQEDState
*s
, unsigned int n
)
248 uint64_t offset
= s
->file_size
;
249 s
->file_size
+= n
* s
->header
.cluster_size
;
253 QEDTable
*qed_alloc_table(BDRVQEDState
*s
)
255 /* Honor O_DIRECT memory alignment requirements */
256 return qemu_blockalign(s
->bs
,
257 s
->header
.cluster_size
* s
->header
.table_size
);
261 * Allocate a new zeroed L2 table
263 static CachedL2Table
*qed_new_l2_table(BDRVQEDState
*s
)
265 CachedL2Table
*l2_table
= qed_alloc_l2_cache_entry(&s
->l2_cache
);
267 l2_table
->table
= qed_alloc_table(s
);
268 l2_table
->offset
= qed_alloc_clusters(s
, s
->header
.table_size
);
270 memset(l2_table
->table
->offsets
, 0,
271 s
->header
.cluster_size
* s
->header
.table_size
);
275 static void qed_aio_next_io(void *opaque
, int ret
);
277 static void qed_plug_allocating_write_reqs(BDRVQEDState
*s
)
279 assert(!s
->allocating_write_reqs_plugged
);
281 s
->allocating_write_reqs_plugged
= true;
284 static void qed_unplug_allocating_write_reqs(BDRVQEDState
*s
)
288 assert(s
->allocating_write_reqs_plugged
);
290 s
->allocating_write_reqs_plugged
= false;
292 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
294 qed_aio_next_io(acb
, 0);
298 static void qed_finish_clear_need_check(void *opaque
, int ret
)
303 static void qed_flush_after_clear_need_check(void *opaque
, int ret
)
305 BDRVQEDState
*s
= opaque
;
307 bdrv_aio_flush(s
->bs
, qed_finish_clear_need_check
, s
);
309 /* No need to wait until flush completes */
310 qed_unplug_allocating_write_reqs(s
);
313 static void qed_clear_need_check(void *opaque
, int ret
)
315 BDRVQEDState
*s
= opaque
;
318 qed_unplug_allocating_write_reqs(s
);
322 s
->header
.features
&= ~QED_F_NEED_CHECK
;
323 qed_write_header(s
, qed_flush_after_clear_need_check
, s
);
326 static void qed_need_check_timer_cb(void *opaque
)
328 BDRVQEDState
*s
= opaque
;
330 /* The timer should only fire when allocating writes have drained */
331 assert(!QSIMPLEQ_FIRST(&s
->allocating_write_reqs
));
333 trace_qed_need_check_timer_cb(s
);
335 qed_plug_allocating_write_reqs(s
);
337 /* Ensure writes are on disk before clearing flag */
338 bdrv_aio_flush(s
->bs
, qed_clear_need_check
, s
);
341 static void qed_start_need_check_timer(BDRVQEDState
*s
)
343 trace_qed_start_need_check_timer(s
);
345 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
348 timer_mod(s
->need_check_timer
, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
) +
349 get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT
);
352 /* It's okay to call this multiple times or when no timer is started */
353 static void qed_cancel_need_check_timer(BDRVQEDState
*s
)
355 trace_qed_cancel_need_check_timer(s
);
356 timer_del(s
->need_check_timer
);
359 static void bdrv_qed_detach_aio_context(BlockDriverState
*bs
)
361 BDRVQEDState
*s
= bs
->opaque
;
363 qed_cancel_need_check_timer(s
);
364 timer_free(s
->need_check_timer
);
367 static void bdrv_qed_attach_aio_context(BlockDriverState
*bs
,
368 AioContext
*new_context
)
370 BDRVQEDState
*s
= bs
->opaque
;
372 s
->need_check_timer
= aio_timer_new(new_context
,
373 QEMU_CLOCK_VIRTUAL
, SCALE_NS
,
374 qed_need_check_timer_cb
, s
);
375 if (s
->header
.features
& QED_F_NEED_CHECK
) {
376 qed_start_need_check_timer(s
);
380 static int bdrv_qed_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
383 BDRVQEDState
*s
= bs
->opaque
;
389 QSIMPLEQ_INIT(&s
->allocating_write_reqs
);
391 ret
= bdrv_pread(bs
->file
->bs
, 0, &le_header
, sizeof(le_header
));
395 qed_header_le_to_cpu(&le_header
, &s
->header
);
397 if (s
->header
.magic
!= QED_MAGIC
) {
398 error_setg(errp
, "Image not in QED format");
401 if (s
->header
.features
& ~QED_FEATURE_MASK
) {
402 /* image uses unsupported feature bits */
403 error_setg(errp
, "Unsupported QED features: %" PRIx64
,
404 s
->header
.features
& ~QED_FEATURE_MASK
);
407 if (!qed_is_cluster_size_valid(s
->header
.cluster_size
)) {
411 /* Round down file size to the last cluster */
412 file_size
= bdrv_getlength(bs
->file
->bs
);
416 s
->file_size
= qed_start_of_cluster(s
, file_size
);
418 if (!qed_is_table_size_valid(s
->header
.table_size
)) {
421 if (!qed_is_image_size_valid(s
->header
.image_size
,
422 s
->header
.cluster_size
,
423 s
->header
.table_size
)) {
426 if (!qed_check_table_offset(s
, s
->header
.l1_table_offset
)) {
430 s
->table_nelems
= (s
->header
.cluster_size
* s
->header
.table_size
) /
432 s
->l2_shift
= ctz32(s
->header
.cluster_size
);
433 s
->l2_mask
= s
->table_nelems
- 1;
434 s
->l1_shift
= s
->l2_shift
+ ctz32(s
->table_nelems
);
436 /* Header size calculation must not overflow uint32_t */
437 if (s
->header
.header_size
> UINT32_MAX
/ s
->header
.cluster_size
) {
441 if ((s
->header
.features
& QED_F_BACKING_FILE
)) {
442 if ((uint64_t)s
->header
.backing_filename_offset
+
443 s
->header
.backing_filename_size
>
444 s
->header
.cluster_size
* s
->header
.header_size
) {
448 ret
= qed_read_string(bs
->file
->bs
, s
->header
.backing_filename_offset
,
449 s
->header
.backing_filename_size
, bs
->backing_file
,
450 sizeof(bs
->backing_file
));
455 if (s
->header
.features
& QED_F_BACKING_FORMAT_NO_PROBE
) {
456 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), "raw");
460 /* Reset unknown autoclear feature bits. This is a backwards
461 * compatibility mechanism that allows images to be opened by older
462 * programs, which "knock out" unknown feature bits. When an image is
463 * opened by a newer program again it can detect that the autoclear
464 * feature is no longer valid.
466 if ((s
->header
.autoclear_features
& ~QED_AUTOCLEAR_FEATURE_MASK
) != 0 &&
467 !bdrv_is_read_only(bs
->file
->bs
) && !(flags
& BDRV_O_INACTIVE
)) {
468 s
->header
.autoclear_features
&= QED_AUTOCLEAR_FEATURE_MASK
;
470 ret
= qed_write_header_sync(s
);
475 /* From here on only known autoclear feature bits are valid */
476 bdrv_flush(bs
->file
->bs
);
479 s
->l1_table
= qed_alloc_table(s
);
480 qed_init_l2_cache(&s
->l2_cache
);
482 ret
= qed_read_l1_table_sync(s
);
487 /* If image was not closed cleanly, check consistency */
488 if (!(flags
& BDRV_O_CHECK
) && (s
->header
.features
& QED_F_NEED_CHECK
)) {
489 /* Read-only images cannot be fixed. There is no risk of corruption
490 * since write operations are not possible. Therefore, allow
491 * potentially inconsistent images to be opened read-only. This can
492 * aid data recovery from an otherwise inconsistent image.
494 if (!bdrv_is_read_only(bs
->file
->bs
) &&
495 !(flags
& BDRV_O_INACTIVE
)) {
496 BdrvCheckResult result
= {0};
498 ret
= qed_check(s
, &result
, true);
505 bdrv_qed_attach_aio_context(bs
, bdrv_get_aio_context(bs
));
509 qed_free_l2_cache(&s
->l2_cache
);
510 qemu_vfree(s
->l1_table
);
515 static void bdrv_qed_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
517 BDRVQEDState
*s
= bs
->opaque
;
519 bs
->bl
.write_zeroes_alignment
= s
->header
.cluster_size
>> BDRV_SECTOR_BITS
;
522 /* We have nothing to do for QED reopen, stubs just return
524 static int bdrv_qed_reopen_prepare(BDRVReopenState
*state
,
525 BlockReopenQueue
*queue
, Error
**errp
)
530 static void bdrv_qed_close(BlockDriverState
*bs
)
532 BDRVQEDState
*s
= bs
->opaque
;
534 bdrv_qed_detach_aio_context(bs
);
536 /* Ensure writes reach stable storage */
537 bdrv_flush(bs
->file
->bs
);
539 /* Clean shutdown, no check required on next open */
540 if (s
->header
.features
& QED_F_NEED_CHECK
) {
541 s
->header
.features
&= ~QED_F_NEED_CHECK
;
542 qed_write_header_sync(s
);
545 qed_free_l2_cache(&s
->l2_cache
);
546 qemu_vfree(s
->l1_table
);
549 static int qed_create(const char *filename
, uint32_t cluster_size
,
550 uint64_t image_size
, uint32_t table_size
,
551 const char *backing_file
, const char *backing_fmt
,
552 QemuOpts
*opts
, Error
**errp
)
556 .cluster_size
= cluster_size
,
557 .table_size
= table_size
,
560 .compat_features
= 0,
561 .l1_table_offset
= cluster_size
,
562 .image_size
= image_size
,
565 uint8_t *l1_table
= NULL
;
566 size_t l1_size
= header
.cluster_size
* header
.table_size
;
567 Error
*local_err
= NULL
;
571 ret
= bdrv_create_file(filename
, opts
, &local_err
);
573 error_propagate(errp
, local_err
);
577 blk
= blk_new_open("image", filename
, NULL
, NULL
,
578 BDRV_O_RDWR
| BDRV_O_CACHE_WB
| BDRV_O_PROTOCOL
,
581 error_propagate(errp
, local_err
);
585 blk_set_allow_write_beyond_eof(blk
, true);
587 /* File must start empty and grow, check truncate is supported */
588 ret
= blk_truncate(blk
, 0);
594 header
.features
|= QED_F_BACKING_FILE
;
595 header
.backing_filename_offset
= sizeof(le_header
);
596 header
.backing_filename_size
= strlen(backing_file
);
598 if (qed_fmt_is_raw(backing_fmt
)) {
599 header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
603 qed_header_cpu_to_le(&header
, &le_header
);
604 ret
= blk_pwrite(blk
, 0, &le_header
, sizeof(le_header
));
608 ret
= blk_pwrite(blk
, sizeof(le_header
), backing_file
,
609 header
.backing_filename_size
);
614 l1_table
= g_malloc0(l1_size
);
615 ret
= blk_pwrite(blk
, header
.l1_table_offset
, l1_table
, l1_size
);
620 ret
= 0; /* success */
627 static int bdrv_qed_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
629 uint64_t image_size
= 0;
630 uint32_t cluster_size
= QED_DEFAULT_CLUSTER_SIZE
;
631 uint32_t table_size
= QED_DEFAULT_TABLE_SIZE
;
632 char *backing_file
= NULL
;
633 char *backing_fmt
= NULL
;
636 image_size
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
638 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
639 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
640 cluster_size
= qemu_opt_get_size_del(opts
,
641 BLOCK_OPT_CLUSTER_SIZE
,
642 QED_DEFAULT_CLUSTER_SIZE
);
643 table_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_TABLE_SIZE
,
644 QED_DEFAULT_TABLE_SIZE
);
646 if (!qed_is_cluster_size_valid(cluster_size
)) {
647 error_setg(errp
, "QED cluster size must be within range [%u, %u] "
649 QED_MIN_CLUSTER_SIZE
, QED_MAX_CLUSTER_SIZE
);
653 if (!qed_is_table_size_valid(table_size
)) {
654 error_setg(errp
, "QED table size must be within range [%u, %u] "
656 QED_MIN_TABLE_SIZE
, QED_MAX_TABLE_SIZE
);
660 if (!qed_is_image_size_valid(image_size
, cluster_size
, table_size
)) {
661 error_setg(errp
, "QED image size must be a non-zero multiple of "
662 "cluster size and less than %" PRIu64
" bytes",
663 qed_max_image_size(cluster_size
, table_size
));
668 ret
= qed_create(filename
, cluster_size
, image_size
, table_size
,
669 backing_file
, backing_fmt
, opts
, errp
);
672 g_free(backing_file
);
678 BlockDriverState
*bs
;
683 BlockDriverState
**file
;
686 static void qed_is_allocated_cb(void *opaque
, int ret
, uint64_t offset
, size_t len
)
688 QEDIsAllocatedCB
*cb
= opaque
;
689 BDRVQEDState
*s
= cb
->bs
->opaque
;
690 *cb
->pnum
= len
/ BDRV_SECTOR_SIZE
;
692 case QED_CLUSTER_FOUND
:
693 offset
|= qed_offset_into_cluster(s
, cb
->pos
);
694 cb
->status
= BDRV_BLOCK_DATA
| BDRV_BLOCK_OFFSET_VALID
| offset
;
695 *cb
->file
= cb
->bs
->file
->bs
;
697 case QED_CLUSTER_ZERO
:
698 cb
->status
= BDRV_BLOCK_ZERO
;
711 qemu_coroutine_enter(cb
->co
, NULL
);
715 static int64_t coroutine_fn
bdrv_qed_co_get_block_status(BlockDriverState
*bs
,
717 int nb_sectors
, int *pnum
,
718 BlockDriverState
**file
)
720 BDRVQEDState
*s
= bs
->opaque
;
721 size_t len
= (size_t)nb_sectors
* BDRV_SECTOR_SIZE
;
722 QEDIsAllocatedCB cb
= {
724 .pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
,
725 .status
= BDRV_BLOCK_OFFSET_MASK
,
729 QEDRequest request
= { .l2_table
= NULL
};
731 qed_find_cluster(s
, &request
, cb
.pos
, len
, qed_is_allocated_cb
, &cb
);
733 /* Now sleep if the callback wasn't invoked immediately */
734 while (cb
.status
== BDRV_BLOCK_OFFSET_MASK
) {
735 cb
.co
= qemu_coroutine_self();
736 qemu_coroutine_yield();
739 qed_unref_l2_cache_entry(request
.l2_table
);
744 static BDRVQEDState
*acb_to_s(QEDAIOCB
*acb
)
746 return acb
->common
.bs
->opaque
;
750 * Read from the backing file or zero-fill if no backing file
753 * @pos: Byte position in device
754 * @qiov: Destination I/O vector
755 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
756 * @cb: Completion function
757 * @opaque: User data for completion function
759 * This function reads qiov->size bytes starting at pos from the backing file.
760 * If there is no backing file then zeroes are read.
762 static void qed_read_backing_file(BDRVQEDState
*s
, uint64_t pos
,
764 QEMUIOVector
**backing_qiov
,
765 BlockCompletionFunc
*cb
, void *opaque
)
767 uint64_t backing_length
= 0;
770 /* If there is a backing file, get its length. Treat the absence of a
771 * backing file like a zero length backing file.
773 if (s
->bs
->backing
) {
774 int64_t l
= bdrv_getlength(s
->bs
->backing
->bs
);
782 /* Zero all sectors if reading beyond the end of the backing file */
783 if (pos
>= backing_length
||
784 pos
+ qiov
->size
> backing_length
) {
785 qemu_iovec_memset(qiov
, 0, 0, qiov
->size
);
788 /* Complete now if there are no backing file sectors to read */
789 if (pos
>= backing_length
) {
794 /* If the read straddles the end of the backing file, shorten it */
795 size
= MIN((uint64_t)backing_length
- pos
, qiov
->size
);
797 assert(*backing_qiov
== NULL
);
798 *backing_qiov
= g_new(QEMUIOVector
, 1);
799 qemu_iovec_init(*backing_qiov
, qiov
->niov
);
800 qemu_iovec_concat(*backing_qiov
, qiov
, 0, size
);
802 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_READ_BACKING_AIO
);
803 bdrv_aio_readv(s
->bs
->backing
->bs
, pos
/ BDRV_SECTOR_SIZE
,
804 *backing_qiov
, size
/ BDRV_SECTOR_SIZE
, cb
, opaque
);
811 QEMUIOVector
*backing_qiov
;
814 } CopyFromBackingFileCB
;
816 static void qed_copy_from_backing_file_cb(void *opaque
, int ret
)
818 CopyFromBackingFileCB
*copy_cb
= opaque
;
819 qemu_vfree(copy_cb
->iov
.iov_base
);
820 gencb_complete(©_cb
->gencb
, ret
);
823 static void qed_copy_from_backing_file_write(void *opaque
, int ret
)
825 CopyFromBackingFileCB
*copy_cb
= opaque
;
826 BDRVQEDState
*s
= copy_cb
->s
;
828 if (copy_cb
->backing_qiov
) {
829 qemu_iovec_destroy(copy_cb
->backing_qiov
);
830 g_free(copy_cb
->backing_qiov
);
831 copy_cb
->backing_qiov
= NULL
;
835 qed_copy_from_backing_file_cb(copy_cb
, ret
);
839 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_COW_WRITE
);
840 bdrv_aio_writev(s
->bs
->file
->bs
, copy_cb
->offset
/ BDRV_SECTOR_SIZE
,
841 ©_cb
->qiov
, copy_cb
->qiov
.size
/ BDRV_SECTOR_SIZE
,
842 qed_copy_from_backing_file_cb
, copy_cb
);
846 * Copy data from backing file into the image
849 * @pos: Byte position in device
850 * @len: Number of bytes
851 * @offset: Byte offset in image file
852 * @cb: Completion function
853 * @opaque: User data for completion function
855 static void qed_copy_from_backing_file(BDRVQEDState
*s
, uint64_t pos
,
856 uint64_t len
, uint64_t offset
,
857 BlockCompletionFunc
*cb
,
860 CopyFromBackingFileCB
*copy_cb
;
862 /* Skip copy entirely if there is no work to do */
868 copy_cb
= gencb_alloc(sizeof(*copy_cb
), cb
, opaque
);
870 copy_cb
->offset
= offset
;
871 copy_cb
->backing_qiov
= NULL
;
872 copy_cb
->iov
.iov_base
= qemu_blockalign(s
->bs
, len
);
873 copy_cb
->iov
.iov_len
= len
;
874 qemu_iovec_init_external(©_cb
->qiov
, ©_cb
->iov
, 1);
876 qed_read_backing_file(s
, pos
, ©_cb
->qiov
, ©_cb
->backing_qiov
,
877 qed_copy_from_backing_file_write
, copy_cb
);
881 * Link one or more contiguous clusters into a table
885 * @index: First cluster index
886 * @n: Number of contiguous clusters
887 * @cluster: First cluster offset
889 * The cluster offset may be an allocated byte offset in the image file, the
890 * zero cluster marker, or the unallocated cluster marker.
892 static void qed_update_l2_table(BDRVQEDState
*s
, QEDTable
*table
, int index
,
893 unsigned int n
, uint64_t cluster
)
896 for (i
= index
; i
< index
+ n
; i
++) {
897 table
->offsets
[i
] = cluster
;
898 if (!qed_offset_is_unalloc_cluster(cluster
) &&
899 !qed_offset_is_zero_cluster(cluster
)) {
900 cluster
+= s
->header
.cluster_size
;
905 static void qed_aio_complete_bh(void *opaque
)
907 QEDAIOCB
*acb
= opaque
;
908 BlockCompletionFunc
*cb
= acb
->common
.cb
;
909 void *user_opaque
= acb
->common
.opaque
;
910 int ret
= acb
->bh_ret
;
912 qemu_bh_delete(acb
->bh
);
915 /* Invoke callback */
916 cb(user_opaque
, ret
);
919 static void qed_aio_complete(QEDAIOCB
*acb
, int ret
)
921 BDRVQEDState
*s
= acb_to_s(acb
);
923 trace_qed_aio_complete(s
, acb
, ret
);
926 qemu_iovec_destroy(&acb
->cur_qiov
);
927 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
929 /* Free the buffer we may have allocated for zero writes */
930 if (acb
->flags
& QED_AIOCB_ZERO
) {
931 qemu_vfree(acb
->qiov
->iov
[0].iov_base
);
932 acb
->qiov
->iov
[0].iov_base
= NULL
;
935 /* Arrange for a bh to invoke the completion function */
937 acb
->bh
= aio_bh_new(bdrv_get_aio_context(acb
->common
.bs
),
938 qed_aio_complete_bh
, acb
);
939 qemu_bh_schedule(acb
->bh
);
941 /* Start next allocating write request waiting behind this one. Note that
942 * requests enqueue themselves when they first hit an unallocated cluster
943 * but they wait until the entire request is finished before waking up the
944 * next request in the queue. This ensures that we don't cycle through
945 * requests multiple times but rather finish one at a time completely.
947 if (acb
== QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
948 QSIMPLEQ_REMOVE_HEAD(&s
->allocating_write_reqs
, next
);
949 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
951 qed_aio_next_io(acb
, 0);
952 } else if (s
->header
.features
& QED_F_NEED_CHECK
) {
953 qed_start_need_check_timer(s
);
959 * Commit the current L2 table to the cache
961 static void qed_commit_l2_update(void *opaque
, int ret
)
963 QEDAIOCB
*acb
= opaque
;
964 BDRVQEDState
*s
= acb_to_s(acb
);
965 CachedL2Table
*l2_table
= acb
->request
.l2_table
;
966 uint64_t l2_offset
= l2_table
->offset
;
968 qed_commit_l2_cache_entry(&s
->l2_cache
, l2_table
);
970 /* This is guaranteed to succeed because we just committed the entry to the
973 acb
->request
.l2_table
= qed_find_l2_cache_entry(&s
->l2_cache
, l2_offset
);
974 assert(acb
->request
.l2_table
!= NULL
);
976 qed_aio_next_io(opaque
, ret
);
980 * Update L1 table with new L2 table offset and write it out
982 static void qed_aio_write_l1_update(void *opaque
, int ret
)
984 QEDAIOCB
*acb
= opaque
;
985 BDRVQEDState
*s
= acb_to_s(acb
);
989 qed_aio_complete(acb
, ret
);
993 index
= qed_l1_index(s
, acb
->cur_pos
);
994 s
->l1_table
->offsets
[index
] = acb
->request
.l2_table
->offset
;
996 qed_write_l1_table(s
, index
, 1, qed_commit_l2_update
, acb
);
1000 * Update L2 table with new cluster offsets and write them out
1002 static void qed_aio_write_l2_update(QEDAIOCB
*acb
, int ret
, uint64_t offset
)
1004 BDRVQEDState
*s
= acb_to_s(acb
);
1005 bool need_alloc
= acb
->find_cluster_ret
== QED_CLUSTER_L1
;
1013 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
1014 acb
->request
.l2_table
= qed_new_l2_table(s
);
1017 index
= qed_l2_index(s
, acb
->cur_pos
);
1018 qed_update_l2_table(s
, acb
->request
.l2_table
->table
, index
, acb
->cur_nclusters
,
1022 /* Write out the whole new L2 table */
1023 qed_write_l2_table(s
, &acb
->request
, 0, s
->table_nelems
, true,
1024 qed_aio_write_l1_update
, acb
);
1026 /* Write out only the updated part of the L2 table */
1027 qed_write_l2_table(s
, &acb
->request
, index
, acb
->cur_nclusters
, false,
1028 qed_aio_next_io
, acb
);
1033 qed_aio_complete(acb
, ret
);
1036 static void qed_aio_write_l2_update_cb(void *opaque
, int ret
)
1038 QEDAIOCB
*acb
= opaque
;
1039 qed_aio_write_l2_update(acb
, ret
, acb
->cur_cluster
);
1043 * Flush new data clusters before updating the L2 table
1045 * This flush is necessary when a backing file is in use. A crash during an
1046 * allocating write could result in empty clusters in the image. If the write
1047 * only touched a subregion of the cluster, then backing image sectors have
1048 * been lost in the untouched region. The solution is to flush after writing a
1049 * new data cluster and before updating the L2 table.
1051 static void qed_aio_write_flush_before_l2_update(void *opaque
, int ret
)
1053 QEDAIOCB
*acb
= opaque
;
1054 BDRVQEDState
*s
= acb_to_s(acb
);
1056 if (!bdrv_aio_flush(s
->bs
->file
->bs
, qed_aio_write_l2_update_cb
, opaque
)) {
1057 qed_aio_complete(acb
, -EIO
);
1062 * Write data to the image file
1064 static void qed_aio_write_main(void *opaque
, int ret
)
1066 QEDAIOCB
*acb
= opaque
;
1067 BDRVQEDState
*s
= acb_to_s(acb
);
1068 uint64_t offset
= acb
->cur_cluster
+
1069 qed_offset_into_cluster(s
, acb
->cur_pos
);
1070 BlockCompletionFunc
*next_fn
;
1072 trace_qed_aio_write_main(s
, acb
, ret
, offset
, acb
->cur_qiov
.size
);
1075 qed_aio_complete(acb
, ret
);
1079 if (acb
->find_cluster_ret
== QED_CLUSTER_FOUND
) {
1080 next_fn
= qed_aio_next_io
;
1082 if (s
->bs
->backing
) {
1083 next_fn
= qed_aio_write_flush_before_l2_update
;
1085 next_fn
= qed_aio_write_l2_update_cb
;
1089 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_WRITE_AIO
);
1090 bdrv_aio_writev(s
->bs
->file
->bs
, offset
/ BDRV_SECTOR_SIZE
,
1091 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1096 * Populate back untouched region of new data cluster
1098 static void qed_aio_write_postfill(void *opaque
, int ret
)
1100 QEDAIOCB
*acb
= opaque
;
1101 BDRVQEDState
*s
= acb_to_s(acb
);
1102 uint64_t start
= acb
->cur_pos
+ acb
->cur_qiov
.size
;
1104 qed_start_of_cluster(s
, start
+ s
->header
.cluster_size
- 1) - start
;
1105 uint64_t offset
= acb
->cur_cluster
+
1106 qed_offset_into_cluster(s
, acb
->cur_pos
) +
1110 qed_aio_complete(acb
, ret
);
1114 trace_qed_aio_write_postfill(s
, acb
, start
, len
, offset
);
1115 qed_copy_from_backing_file(s
, start
, len
, offset
,
1116 qed_aio_write_main
, acb
);
1120 * Populate front untouched region of new data cluster
1122 static void qed_aio_write_prefill(void *opaque
, int ret
)
1124 QEDAIOCB
*acb
= opaque
;
1125 BDRVQEDState
*s
= acb_to_s(acb
);
1126 uint64_t start
= qed_start_of_cluster(s
, acb
->cur_pos
);
1127 uint64_t len
= qed_offset_into_cluster(s
, acb
->cur_pos
);
1129 trace_qed_aio_write_prefill(s
, acb
, start
, len
, acb
->cur_cluster
);
1130 qed_copy_from_backing_file(s
, start
, len
, acb
->cur_cluster
,
1131 qed_aio_write_postfill
, acb
);
1135 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1137 static bool qed_should_set_need_check(BDRVQEDState
*s
)
1139 /* The flush before L2 update path ensures consistency */
1140 if (s
->bs
->backing
) {
1144 return !(s
->header
.features
& QED_F_NEED_CHECK
);
1147 static void qed_aio_write_zero_cluster(void *opaque
, int ret
)
1149 QEDAIOCB
*acb
= opaque
;
1152 qed_aio_complete(acb
, ret
);
1156 qed_aio_write_l2_update(acb
, 0, 1);
1160 * Write new data cluster
1162 * @acb: Write request
1163 * @len: Length in bytes
1165 * This path is taken when writing to previously unallocated clusters.
1167 static void qed_aio_write_alloc(QEDAIOCB
*acb
, size_t len
)
1169 BDRVQEDState
*s
= acb_to_s(acb
);
1170 BlockCompletionFunc
*cb
;
1172 /* Cancel timer when the first allocating request comes in */
1173 if (QSIMPLEQ_EMPTY(&s
->allocating_write_reqs
)) {
1174 qed_cancel_need_check_timer(s
);
1177 /* Freeze this request if another allocating write is in progress */
1178 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
1179 QSIMPLEQ_INSERT_TAIL(&s
->allocating_write_reqs
, acb
, next
);
1181 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
) ||
1182 s
->allocating_write_reqs_plugged
) {
1183 return; /* wait for existing request to finish */
1186 acb
->cur_nclusters
= qed_bytes_to_clusters(s
,
1187 qed_offset_into_cluster(s
, acb
->cur_pos
) + len
);
1188 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1190 if (acb
->flags
& QED_AIOCB_ZERO
) {
1191 /* Skip ahead if the clusters are already zero */
1192 if (acb
->find_cluster_ret
== QED_CLUSTER_ZERO
) {
1193 qed_aio_next_io(acb
, 0);
1197 cb
= qed_aio_write_zero_cluster
;
1199 cb
= qed_aio_write_prefill
;
1200 acb
->cur_cluster
= qed_alloc_clusters(s
, acb
->cur_nclusters
);
1203 if (qed_should_set_need_check(s
)) {
1204 s
->header
.features
|= QED_F_NEED_CHECK
;
1205 qed_write_header(s
, cb
, acb
);
1212 * Write data cluster in place
1214 * @acb: Write request
1215 * @offset: Cluster offset in bytes
1216 * @len: Length in bytes
1218 * This path is taken when writing to already allocated clusters.
1220 static void qed_aio_write_inplace(QEDAIOCB
*acb
, uint64_t offset
, size_t len
)
1222 /* Allocate buffer for zero writes */
1223 if (acb
->flags
& QED_AIOCB_ZERO
) {
1224 struct iovec
*iov
= acb
->qiov
->iov
;
1226 if (!iov
->iov_base
) {
1227 iov
->iov_base
= qemu_try_blockalign(acb
->common
.bs
, iov
->iov_len
);
1228 if (iov
->iov_base
== NULL
) {
1229 qed_aio_complete(acb
, -ENOMEM
);
1232 memset(iov
->iov_base
, 0, iov
->iov_len
);
1236 /* Calculate the I/O vector */
1237 acb
->cur_cluster
= offset
;
1238 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1240 /* Do the actual write */
1241 qed_aio_write_main(acb
, 0);
1245 * Write data cluster
1247 * @opaque: Write request
1248 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1250 * @offset: Cluster offset in bytes
1251 * @len: Length in bytes
1253 * Callback from qed_find_cluster().
1255 static void qed_aio_write_data(void *opaque
, int ret
,
1256 uint64_t offset
, size_t len
)
1258 QEDAIOCB
*acb
= opaque
;
1260 trace_qed_aio_write_data(acb_to_s(acb
), acb
, ret
, offset
, len
);
1262 acb
->find_cluster_ret
= ret
;
1265 case QED_CLUSTER_FOUND
:
1266 qed_aio_write_inplace(acb
, offset
, len
);
1269 case QED_CLUSTER_L2
:
1270 case QED_CLUSTER_L1
:
1271 case QED_CLUSTER_ZERO
:
1272 qed_aio_write_alloc(acb
, len
);
1276 qed_aio_complete(acb
, ret
);
1284 * @opaque: Read request
1285 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1287 * @offset: Cluster offset in bytes
1288 * @len: Length in bytes
1290 * Callback from qed_find_cluster().
1292 static void qed_aio_read_data(void *opaque
, int ret
,
1293 uint64_t offset
, size_t len
)
1295 QEDAIOCB
*acb
= opaque
;
1296 BDRVQEDState
*s
= acb_to_s(acb
);
1297 BlockDriverState
*bs
= acb
->common
.bs
;
1299 /* Adjust offset into cluster */
1300 offset
+= qed_offset_into_cluster(s
, acb
->cur_pos
);
1302 trace_qed_aio_read_data(s
, acb
, ret
, offset
, len
);
1308 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1310 /* Handle zero cluster and backing file reads */
1311 if (ret
== QED_CLUSTER_ZERO
) {
1312 qemu_iovec_memset(&acb
->cur_qiov
, 0, 0, acb
->cur_qiov
.size
);
1313 qed_aio_next_io(acb
, 0);
1315 } else if (ret
!= QED_CLUSTER_FOUND
) {
1316 qed_read_backing_file(s
, acb
->cur_pos
, &acb
->cur_qiov
,
1317 &acb
->backing_qiov
, qed_aio_next_io
, acb
);
1321 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1322 bdrv_aio_readv(bs
->file
->bs
, offset
/ BDRV_SECTOR_SIZE
,
1323 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1324 qed_aio_next_io
, acb
);
1328 qed_aio_complete(acb
, ret
);
1332 * Begin next I/O or complete the request
1334 static void qed_aio_next_io(void *opaque
, int ret
)
1336 QEDAIOCB
*acb
= opaque
;
1337 BDRVQEDState
*s
= acb_to_s(acb
);
1338 QEDFindClusterFunc
*io_fn
= (acb
->flags
& QED_AIOCB_WRITE
) ?
1339 qed_aio_write_data
: qed_aio_read_data
;
1341 trace_qed_aio_next_io(s
, acb
, ret
, acb
->cur_pos
+ acb
->cur_qiov
.size
);
1343 if (acb
->backing_qiov
) {
1344 qemu_iovec_destroy(acb
->backing_qiov
);
1345 g_free(acb
->backing_qiov
);
1346 acb
->backing_qiov
= NULL
;
1349 /* Handle I/O error */
1351 qed_aio_complete(acb
, ret
);
1355 acb
->qiov_offset
+= acb
->cur_qiov
.size
;
1356 acb
->cur_pos
+= acb
->cur_qiov
.size
;
1357 qemu_iovec_reset(&acb
->cur_qiov
);
1359 /* Complete request */
1360 if (acb
->cur_pos
>= acb
->end_pos
) {
1361 qed_aio_complete(acb
, 0);
1365 /* Find next cluster and start I/O */
1366 qed_find_cluster(s
, &acb
->request
,
1367 acb
->cur_pos
, acb
->end_pos
- acb
->cur_pos
,
1371 static BlockAIOCB
*qed_aio_setup(BlockDriverState
*bs
,
1373 QEMUIOVector
*qiov
, int nb_sectors
,
1374 BlockCompletionFunc
*cb
,
1375 void *opaque
, int flags
)
1377 QEDAIOCB
*acb
= qemu_aio_get(&qed_aiocb_info
, bs
, cb
, opaque
);
1379 trace_qed_aio_setup(bs
->opaque
, acb
, sector_num
, nb_sectors
,
1384 acb
->qiov_offset
= 0;
1385 acb
->cur_pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
;
1386 acb
->end_pos
= acb
->cur_pos
+ nb_sectors
* BDRV_SECTOR_SIZE
;
1387 acb
->backing_qiov
= NULL
;
1388 acb
->request
.l2_table
= NULL
;
1389 qemu_iovec_init(&acb
->cur_qiov
, qiov
->niov
);
1392 qed_aio_next_io(acb
, 0);
1393 return &acb
->common
;
1396 static BlockAIOCB
*bdrv_qed_aio_readv(BlockDriverState
*bs
,
1398 QEMUIOVector
*qiov
, int nb_sectors
,
1399 BlockCompletionFunc
*cb
,
1402 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
, opaque
, 0);
1405 static BlockAIOCB
*bdrv_qed_aio_writev(BlockDriverState
*bs
,
1407 QEMUIOVector
*qiov
, int nb_sectors
,
1408 BlockCompletionFunc
*cb
,
1411 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
,
1412 opaque
, QED_AIOCB_WRITE
);
1421 static void coroutine_fn
qed_co_write_zeroes_cb(void *opaque
, int ret
)
1423 QEDWriteZeroesCB
*cb
= opaque
;
1428 qemu_coroutine_enter(cb
->co
, NULL
);
1432 static int coroutine_fn
bdrv_qed_co_write_zeroes(BlockDriverState
*bs
,
1435 BdrvRequestFlags flags
)
1437 BlockAIOCB
*blockacb
;
1438 BDRVQEDState
*s
= bs
->opaque
;
1439 QEDWriteZeroesCB cb
= { .done
= false };
1443 /* Refuse if there are untouched backing file sectors */
1445 if (qed_offset_into_cluster(s
, sector_num
* BDRV_SECTOR_SIZE
) != 0) {
1448 if (qed_offset_into_cluster(s
, nb_sectors
* BDRV_SECTOR_SIZE
) != 0) {
1453 /* Zero writes start without an I/O buffer. If a buffer becomes necessary
1454 * then it will be allocated during request processing.
1456 iov
.iov_base
= NULL
,
1457 iov
.iov_len
= nb_sectors
* BDRV_SECTOR_SIZE
,
1459 qemu_iovec_init_external(&qiov
, &iov
, 1);
1460 blockacb
= qed_aio_setup(bs
, sector_num
, &qiov
, nb_sectors
,
1461 qed_co_write_zeroes_cb
, &cb
,
1462 QED_AIOCB_WRITE
| QED_AIOCB_ZERO
);
1467 cb
.co
= qemu_coroutine_self();
1468 qemu_coroutine_yield();
1474 static int bdrv_qed_truncate(BlockDriverState
*bs
, int64_t offset
)
1476 BDRVQEDState
*s
= bs
->opaque
;
1477 uint64_t old_image_size
;
1480 if (!qed_is_image_size_valid(offset
, s
->header
.cluster_size
,
1481 s
->header
.table_size
)) {
1485 /* Shrinking is currently not supported */
1486 if ((uint64_t)offset
< s
->header
.image_size
) {
1490 old_image_size
= s
->header
.image_size
;
1491 s
->header
.image_size
= offset
;
1492 ret
= qed_write_header_sync(s
);
1494 s
->header
.image_size
= old_image_size
;
1499 static int64_t bdrv_qed_getlength(BlockDriverState
*bs
)
1501 BDRVQEDState
*s
= bs
->opaque
;
1502 return s
->header
.image_size
;
1505 static int bdrv_qed_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1507 BDRVQEDState
*s
= bs
->opaque
;
1509 memset(bdi
, 0, sizeof(*bdi
));
1510 bdi
->cluster_size
= s
->header
.cluster_size
;
1511 bdi
->is_dirty
= s
->header
.features
& QED_F_NEED_CHECK
;
1512 bdi
->unallocated_blocks_are_zero
= true;
1513 bdi
->can_write_zeroes_with_unmap
= true;
1517 static int bdrv_qed_change_backing_file(BlockDriverState
*bs
,
1518 const char *backing_file
,
1519 const char *backing_fmt
)
1521 BDRVQEDState
*s
= bs
->opaque
;
1522 QEDHeader new_header
, le_header
;
1524 size_t buffer_len
, backing_file_len
;
1527 /* Refuse to set backing filename if unknown compat feature bits are
1528 * active. If the image uses an unknown compat feature then we may not
1529 * know the layout of data following the header structure and cannot safely
1532 if (backing_file
&& (s
->header
.compat_features
&
1533 ~QED_COMPAT_FEATURE_MASK
)) {
1537 memcpy(&new_header
, &s
->header
, sizeof(new_header
));
1539 new_header
.features
&= ~(QED_F_BACKING_FILE
|
1540 QED_F_BACKING_FORMAT_NO_PROBE
);
1542 /* Adjust feature flags */
1544 new_header
.features
|= QED_F_BACKING_FILE
;
1546 if (qed_fmt_is_raw(backing_fmt
)) {
1547 new_header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
1551 /* Calculate new header size */
1552 backing_file_len
= 0;
1555 backing_file_len
= strlen(backing_file
);
1558 buffer_len
= sizeof(new_header
);
1559 new_header
.backing_filename_offset
= buffer_len
;
1560 new_header
.backing_filename_size
= backing_file_len
;
1561 buffer_len
+= backing_file_len
;
1563 /* Make sure we can rewrite header without failing */
1564 if (buffer_len
> new_header
.header_size
* new_header
.cluster_size
) {
1568 /* Prepare new header */
1569 buffer
= g_malloc(buffer_len
);
1571 qed_header_cpu_to_le(&new_header
, &le_header
);
1572 memcpy(buffer
, &le_header
, sizeof(le_header
));
1573 buffer_len
= sizeof(le_header
);
1576 memcpy(buffer
+ buffer_len
, backing_file
, backing_file_len
);
1577 buffer_len
+= backing_file_len
;
1580 /* Write new header */
1581 ret
= bdrv_pwrite_sync(bs
->file
->bs
, 0, buffer
, buffer_len
);
1584 memcpy(&s
->header
, &new_header
, sizeof(new_header
));
1589 static void bdrv_qed_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
1591 BDRVQEDState
*s
= bs
->opaque
;
1592 Error
*local_err
= NULL
;
1597 bdrv_invalidate_cache(bs
->file
->bs
, &local_err
);
1599 error_propagate(errp
, local_err
);
1603 memset(s
, 0, sizeof(BDRVQEDState
));
1604 ret
= bdrv_qed_open(bs
, NULL
, bs
->open_flags
, &local_err
);
1606 error_propagate(errp
, local_err
);
1607 error_prepend(errp
, "Could not reopen qed layer: ");
1609 } else if (ret
< 0) {
1610 error_setg_errno(errp
, -ret
, "Could not reopen qed layer");
1615 static int bdrv_qed_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
1618 BDRVQEDState
*s
= bs
->opaque
;
1620 return qed_check(s
, result
, !!fix
);
1623 static QemuOptsList qed_create_opts
= {
1624 .name
= "qed-create-opts",
1625 .head
= QTAILQ_HEAD_INITIALIZER(qed_create_opts
.head
),
1628 .name
= BLOCK_OPT_SIZE
,
1629 .type
= QEMU_OPT_SIZE
,
1630 .help
= "Virtual disk size"
1633 .name
= BLOCK_OPT_BACKING_FILE
,
1634 .type
= QEMU_OPT_STRING
,
1635 .help
= "File name of a base image"
1638 .name
= BLOCK_OPT_BACKING_FMT
,
1639 .type
= QEMU_OPT_STRING
,
1640 .help
= "Image format of the base image"
1643 .name
= BLOCK_OPT_CLUSTER_SIZE
,
1644 .type
= QEMU_OPT_SIZE
,
1645 .help
= "Cluster size (in bytes)",
1646 .def_value_str
= stringify(QED_DEFAULT_CLUSTER_SIZE
)
1649 .name
= BLOCK_OPT_TABLE_SIZE
,
1650 .type
= QEMU_OPT_SIZE
,
1651 .help
= "L1/L2 table size (in clusters)"
1653 { /* end of list */ }
1657 static BlockDriver bdrv_qed
= {
1658 .format_name
= "qed",
1659 .instance_size
= sizeof(BDRVQEDState
),
1660 .create_opts
= &qed_create_opts
,
1661 .supports_backing
= true,
1663 .bdrv_probe
= bdrv_qed_probe
,
1664 .bdrv_open
= bdrv_qed_open
,
1665 .bdrv_close
= bdrv_qed_close
,
1666 .bdrv_reopen_prepare
= bdrv_qed_reopen_prepare
,
1667 .bdrv_create
= bdrv_qed_create
,
1668 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
1669 .bdrv_co_get_block_status
= bdrv_qed_co_get_block_status
,
1670 .bdrv_aio_readv
= bdrv_qed_aio_readv
,
1671 .bdrv_aio_writev
= bdrv_qed_aio_writev
,
1672 .bdrv_co_write_zeroes
= bdrv_qed_co_write_zeroes
,
1673 .bdrv_truncate
= bdrv_qed_truncate
,
1674 .bdrv_getlength
= bdrv_qed_getlength
,
1675 .bdrv_get_info
= bdrv_qed_get_info
,
1676 .bdrv_refresh_limits
= bdrv_qed_refresh_limits
,
1677 .bdrv_change_backing_file
= bdrv_qed_change_backing_file
,
1678 .bdrv_invalidate_cache
= bdrv_qed_invalidate_cache
,
1679 .bdrv_check
= bdrv_qed_check
,
1680 .bdrv_detach_aio_context
= bdrv_qed_detach_aio_context
,
1681 .bdrv_attach_aio_context
= bdrv_qed_attach_aio_context
,
1684 static void bdrv_qed_init(void)
1686 bdrv_register(&bdrv_qed
);
1689 block_init(bdrv_qed_init
);