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 "qapi/error.h"
17 #include "qemu/timer.h"
18 #include "qemu/bswap.h"
21 #include "qapi/qmp/qerror.h"
22 #include "migration/migration.h"
23 #include "sysemu/block-backend.h"
25 static const AIOCBInfo qed_aiocb_info
= {
26 .aiocb_size
= sizeof(QEDAIOCB
),
29 static int bdrv_qed_probe(const uint8_t *buf
, int buf_size
,
32 const QEDHeader
*header
= (const QEDHeader
*)buf
;
34 if (buf_size
< sizeof(*header
)) {
37 if (le32_to_cpu(header
->magic
) != QED_MAGIC
) {
44 * Check whether an image format is raw
46 * @fmt: Backing file format, may be NULL
48 static bool qed_fmt_is_raw(const char *fmt
)
50 return fmt
&& strcmp(fmt
, "raw") == 0;
53 static void qed_header_le_to_cpu(const QEDHeader
*le
, QEDHeader
*cpu
)
55 cpu
->magic
= le32_to_cpu(le
->magic
);
56 cpu
->cluster_size
= le32_to_cpu(le
->cluster_size
);
57 cpu
->table_size
= le32_to_cpu(le
->table_size
);
58 cpu
->header_size
= le32_to_cpu(le
->header_size
);
59 cpu
->features
= le64_to_cpu(le
->features
);
60 cpu
->compat_features
= le64_to_cpu(le
->compat_features
);
61 cpu
->autoclear_features
= le64_to_cpu(le
->autoclear_features
);
62 cpu
->l1_table_offset
= le64_to_cpu(le
->l1_table_offset
);
63 cpu
->image_size
= le64_to_cpu(le
->image_size
);
64 cpu
->backing_filename_offset
= le32_to_cpu(le
->backing_filename_offset
);
65 cpu
->backing_filename_size
= le32_to_cpu(le
->backing_filename_size
);
68 static void qed_header_cpu_to_le(const QEDHeader
*cpu
, QEDHeader
*le
)
70 le
->magic
= cpu_to_le32(cpu
->magic
);
71 le
->cluster_size
= cpu_to_le32(cpu
->cluster_size
);
72 le
->table_size
= cpu_to_le32(cpu
->table_size
);
73 le
->header_size
= cpu_to_le32(cpu
->header_size
);
74 le
->features
= cpu_to_le64(cpu
->features
);
75 le
->compat_features
= cpu_to_le64(cpu
->compat_features
);
76 le
->autoclear_features
= cpu_to_le64(cpu
->autoclear_features
);
77 le
->l1_table_offset
= cpu_to_le64(cpu
->l1_table_offset
);
78 le
->image_size
= cpu_to_le64(cpu
->image_size
);
79 le
->backing_filename_offset
= cpu_to_le32(cpu
->backing_filename_offset
);
80 le
->backing_filename_size
= cpu_to_le32(cpu
->backing_filename_size
);
83 int qed_write_header_sync(BDRVQEDState
*s
)
88 qed_header_cpu_to_le(&s
->header
, &le
);
89 ret
= bdrv_pwrite(s
->bs
->file
, 0, &le
, sizeof(le
));
90 if (ret
!= sizeof(le
)) {
105 static void qed_write_header_cb(void *opaque
, int ret
)
107 QEDWriteHeaderCB
*write_header_cb
= opaque
;
109 qemu_vfree(write_header_cb
->buf
);
110 gencb_complete(write_header_cb
, ret
);
113 static void qed_write_header_read_cb(void *opaque
, int ret
)
115 QEDWriteHeaderCB
*write_header_cb
= opaque
;
116 BDRVQEDState
*s
= write_header_cb
->s
;
119 qed_write_header_cb(write_header_cb
, ret
);
124 qed_header_cpu_to_le(&s
->header
, (QEDHeader
*)write_header_cb
->buf
);
126 bdrv_aio_writev(s
->bs
->file
, 0, &write_header_cb
->qiov
,
127 write_header_cb
->nsectors
, qed_write_header_cb
,
132 * Update header in-place (does not rewrite backing filename or other strings)
134 * This function only updates known header fields in-place and does not affect
135 * extra data after the QED header.
137 static void qed_write_header(BDRVQEDState
*s
, BlockCompletionFunc cb
,
140 /* We must write full sectors for O_DIRECT but cannot necessarily generate
141 * the data following the header if an unrecognized compat feature is
142 * active. Therefore, first read the sectors containing the header, update
143 * them, and write back.
146 int nsectors
= DIV_ROUND_UP(sizeof(QEDHeader
), BDRV_SECTOR_SIZE
);
147 size_t len
= nsectors
* BDRV_SECTOR_SIZE
;
148 QEDWriteHeaderCB
*write_header_cb
= gencb_alloc(sizeof(*write_header_cb
),
151 write_header_cb
->s
= s
;
152 write_header_cb
->nsectors
= nsectors
;
153 write_header_cb
->buf
= qemu_blockalign(s
->bs
, len
);
154 write_header_cb
->iov
.iov_base
= write_header_cb
->buf
;
155 write_header_cb
->iov
.iov_len
= len
;
156 qemu_iovec_init_external(&write_header_cb
->qiov
, &write_header_cb
->iov
, 1);
158 bdrv_aio_readv(s
->bs
->file
, 0, &write_header_cb
->qiov
, nsectors
,
159 qed_write_header_read_cb
, write_header_cb
);
162 static uint64_t qed_max_image_size(uint32_t cluster_size
, uint32_t table_size
)
164 uint64_t table_entries
;
167 table_entries
= (table_size
* cluster_size
) / sizeof(uint64_t);
168 l2_size
= table_entries
* cluster_size
;
170 return l2_size
* table_entries
;
173 static bool qed_is_cluster_size_valid(uint32_t cluster_size
)
175 if (cluster_size
< QED_MIN_CLUSTER_SIZE
||
176 cluster_size
> QED_MAX_CLUSTER_SIZE
) {
179 if (cluster_size
& (cluster_size
- 1)) {
180 return false; /* not power of 2 */
185 static bool qed_is_table_size_valid(uint32_t table_size
)
187 if (table_size
< QED_MIN_TABLE_SIZE
||
188 table_size
> QED_MAX_TABLE_SIZE
) {
191 if (table_size
& (table_size
- 1)) {
192 return false; /* not power of 2 */
197 static bool qed_is_image_size_valid(uint64_t image_size
, uint32_t cluster_size
,
200 if (image_size
% BDRV_SECTOR_SIZE
!= 0) {
201 return false; /* not multiple of sector size */
203 if (image_size
> qed_max_image_size(cluster_size
, table_size
)) {
204 return false; /* image is too large */
210 * Read a string of known length from the image file
213 * @offset: File offset to start of string, in bytes
214 * @n: String length in bytes
215 * @buf: Destination buffer
216 * @buflen: Destination buffer length in bytes
217 * @ret: 0 on success, -errno on failure
219 * The string is NUL-terminated.
221 static int qed_read_string(BdrvChild
*file
, uint64_t offset
, size_t n
,
222 char *buf
, size_t buflen
)
228 ret
= bdrv_pread(file
, offset
, buf
, n
);
237 * Allocate new clusters
240 * @n: Number of contiguous clusters to allocate
241 * @ret: Offset of first allocated cluster
243 * This function only produces the offset where the new clusters should be
244 * written. It updates BDRVQEDState but does not make any changes to the image
247 static uint64_t qed_alloc_clusters(BDRVQEDState
*s
, unsigned int n
)
249 uint64_t offset
= s
->file_size
;
250 s
->file_size
+= n
* s
->header
.cluster_size
;
254 QEDTable
*qed_alloc_table(BDRVQEDState
*s
)
256 /* Honor O_DIRECT memory alignment requirements */
257 return qemu_blockalign(s
->bs
,
258 s
->header
.cluster_size
* s
->header
.table_size
);
262 * Allocate a new zeroed L2 table
264 static CachedL2Table
*qed_new_l2_table(BDRVQEDState
*s
)
266 CachedL2Table
*l2_table
= qed_alloc_l2_cache_entry(&s
->l2_cache
);
268 l2_table
->table
= qed_alloc_table(s
);
269 l2_table
->offset
= qed_alloc_clusters(s
, s
->header
.table_size
);
271 memset(l2_table
->table
->offsets
, 0,
272 s
->header
.cluster_size
* s
->header
.table_size
);
276 static void qed_aio_next_io(QEDAIOCB
*acb
, int ret
);
278 static void qed_aio_start_io(QEDAIOCB
*acb
)
280 qed_aio_next_io(acb
, 0);
283 static void qed_aio_next_io_cb(void *opaque
, int ret
)
285 QEDAIOCB
*acb
= opaque
;
287 qed_aio_next_io(acb
, ret
);
290 static void qed_plug_allocating_write_reqs(BDRVQEDState
*s
)
292 assert(!s
->allocating_write_reqs_plugged
);
294 s
->allocating_write_reqs_plugged
= true;
297 static void qed_unplug_allocating_write_reqs(BDRVQEDState
*s
)
301 assert(s
->allocating_write_reqs_plugged
);
303 s
->allocating_write_reqs_plugged
= false;
305 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
307 qed_aio_start_io(acb
);
311 static void qed_finish_clear_need_check(void *opaque
, int ret
)
316 static void qed_flush_after_clear_need_check(void *opaque
, int ret
)
318 BDRVQEDState
*s
= opaque
;
320 bdrv_aio_flush(s
->bs
, qed_finish_clear_need_check
, s
);
322 /* No need to wait until flush completes */
323 qed_unplug_allocating_write_reqs(s
);
326 static void qed_clear_need_check(void *opaque
, int ret
)
328 BDRVQEDState
*s
= opaque
;
331 qed_unplug_allocating_write_reqs(s
);
335 s
->header
.features
&= ~QED_F_NEED_CHECK
;
336 qed_write_header(s
, qed_flush_after_clear_need_check
, s
);
339 static void qed_need_check_timer_cb(void *opaque
)
341 BDRVQEDState
*s
= opaque
;
343 /* The timer should only fire when allocating writes have drained */
344 assert(!QSIMPLEQ_FIRST(&s
->allocating_write_reqs
));
346 trace_qed_need_check_timer_cb(s
);
349 qed_plug_allocating_write_reqs(s
);
351 /* Ensure writes are on disk before clearing flag */
352 bdrv_aio_flush(s
->bs
->file
->bs
, qed_clear_need_check
, s
);
356 void qed_acquire(BDRVQEDState
*s
)
358 aio_context_acquire(bdrv_get_aio_context(s
->bs
));
361 void qed_release(BDRVQEDState
*s
)
363 aio_context_release(bdrv_get_aio_context(s
->bs
));
366 static void qed_start_need_check_timer(BDRVQEDState
*s
)
368 trace_qed_start_need_check_timer(s
);
370 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
373 timer_mod(s
->need_check_timer
, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
) +
374 NANOSECONDS_PER_SECOND
* QED_NEED_CHECK_TIMEOUT
);
377 /* It's okay to call this multiple times or when no timer is started */
378 static void qed_cancel_need_check_timer(BDRVQEDState
*s
)
380 trace_qed_cancel_need_check_timer(s
);
381 timer_del(s
->need_check_timer
);
384 static void bdrv_qed_detach_aio_context(BlockDriverState
*bs
)
386 BDRVQEDState
*s
= bs
->opaque
;
388 qed_cancel_need_check_timer(s
);
389 timer_free(s
->need_check_timer
);
392 static void bdrv_qed_attach_aio_context(BlockDriverState
*bs
,
393 AioContext
*new_context
)
395 BDRVQEDState
*s
= bs
->opaque
;
397 s
->need_check_timer
= aio_timer_new(new_context
,
398 QEMU_CLOCK_VIRTUAL
, SCALE_NS
,
399 qed_need_check_timer_cb
, s
);
400 if (s
->header
.features
& QED_F_NEED_CHECK
) {
401 qed_start_need_check_timer(s
);
405 static void bdrv_qed_drain(BlockDriverState
*bs
)
407 BDRVQEDState
*s
= bs
->opaque
;
409 /* Fire the timer immediately in order to start doing I/O as soon as the
412 if (s
->need_check_timer
&& timer_pending(s
->need_check_timer
)) {
413 qed_cancel_need_check_timer(s
);
414 qed_need_check_timer_cb(s
);
418 static int bdrv_qed_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
421 BDRVQEDState
*s
= bs
->opaque
;
427 QSIMPLEQ_INIT(&s
->allocating_write_reqs
);
429 ret
= bdrv_pread(bs
->file
, 0, &le_header
, sizeof(le_header
));
433 qed_header_le_to_cpu(&le_header
, &s
->header
);
435 if (s
->header
.magic
!= QED_MAGIC
) {
436 error_setg(errp
, "Image not in QED format");
439 if (s
->header
.features
& ~QED_FEATURE_MASK
) {
440 /* image uses unsupported feature bits */
441 error_setg(errp
, "Unsupported QED features: %" PRIx64
,
442 s
->header
.features
& ~QED_FEATURE_MASK
);
445 if (!qed_is_cluster_size_valid(s
->header
.cluster_size
)) {
449 /* Round down file size to the last cluster */
450 file_size
= bdrv_getlength(bs
->file
->bs
);
454 s
->file_size
= qed_start_of_cluster(s
, file_size
);
456 if (!qed_is_table_size_valid(s
->header
.table_size
)) {
459 if (!qed_is_image_size_valid(s
->header
.image_size
,
460 s
->header
.cluster_size
,
461 s
->header
.table_size
)) {
464 if (!qed_check_table_offset(s
, s
->header
.l1_table_offset
)) {
468 s
->table_nelems
= (s
->header
.cluster_size
* s
->header
.table_size
) /
470 s
->l2_shift
= ctz32(s
->header
.cluster_size
);
471 s
->l2_mask
= s
->table_nelems
- 1;
472 s
->l1_shift
= s
->l2_shift
+ ctz32(s
->table_nelems
);
474 /* Header size calculation must not overflow uint32_t */
475 if (s
->header
.header_size
> UINT32_MAX
/ s
->header
.cluster_size
) {
479 if ((s
->header
.features
& QED_F_BACKING_FILE
)) {
480 if ((uint64_t)s
->header
.backing_filename_offset
+
481 s
->header
.backing_filename_size
>
482 s
->header
.cluster_size
* s
->header
.header_size
) {
486 ret
= qed_read_string(bs
->file
, s
->header
.backing_filename_offset
,
487 s
->header
.backing_filename_size
, bs
->backing_file
,
488 sizeof(bs
->backing_file
));
493 if (s
->header
.features
& QED_F_BACKING_FORMAT_NO_PROBE
) {
494 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), "raw");
498 /* Reset unknown autoclear feature bits. This is a backwards
499 * compatibility mechanism that allows images to be opened by older
500 * programs, which "knock out" unknown feature bits. When an image is
501 * opened by a newer program again it can detect that the autoclear
502 * feature is no longer valid.
504 if ((s
->header
.autoclear_features
& ~QED_AUTOCLEAR_FEATURE_MASK
) != 0 &&
505 !bdrv_is_read_only(bs
->file
->bs
) && !(flags
& BDRV_O_INACTIVE
)) {
506 s
->header
.autoclear_features
&= QED_AUTOCLEAR_FEATURE_MASK
;
508 ret
= qed_write_header_sync(s
);
513 /* From here on only known autoclear feature bits are valid */
514 bdrv_flush(bs
->file
->bs
);
517 s
->l1_table
= qed_alloc_table(s
);
518 qed_init_l2_cache(&s
->l2_cache
);
520 ret
= qed_read_l1_table_sync(s
);
525 /* If image was not closed cleanly, check consistency */
526 if (!(flags
& BDRV_O_CHECK
) && (s
->header
.features
& QED_F_NEED_CHECK
)) {
527 /* Read-only images cannot be fixed. There is no risk of corruption
528 * since write operations are not possible. Therefore, allow
529 * potentially inconsistent images to be opened read-only. This can
530 * aid data recovery from an otherwise inconsistent image.
532 if (!bdrv_is_read_only(bs
->file
->bs
) &&
533 !(flags
& BDRV_O_INACTIVE
)) {
534 BdrvCheckResult result
= {0};
536 ret
= qed_check(s
, &result
, true);
543 bdrv_qed_attach_aio_context(bs
, bdrv_get_aio_context(bs
));
547 qed_free_l2_cache(&s
->l2_cache
);
548 qemu_vfree(s
->l1_table
);
553 static void bdrv_qed_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
555 BDRVQEDState
*s
= bs
->opaque
;
557 bs
->bl
.pwrite_zeroes_alignment
= s
->header
.cluster_size
;
560 /* We have nothing to do for QED reopen, stubs just return
562 static int bdrv_qed_reopen_prepare(BDRVReopenState
*state
,
563 BlockReopenQueue
*queue
, Error
**errp
)
568 static void bdrv_qed_close(BlockDriverState
*bs
)
570 BDRVQEDState
*s
= bs
->opaque
;
572 bdrv_qed_detach_aio_context(bs
);
574 /* Ensure writes reach stable storage */
575 bdrv_flush(bs
->file
->bs
);
577 /* Clean shutdown, no check required on next open */
578 if (s
->header
.features
& QED_F_NEED_CHECK
) {
579 s
->header
.features
&= ~QED_F_NEED_CHECK
;
580 qed_write_header_sync(s
);
583 qed_free_l2_cache(&s
->l2_cache
);
584 qemu_vfree(s
->l1_table
);
587 static int qed_create(const char *filename
, uint32_t cluster_size
,
588 uint64_t image_size
, uint32_t table_size
,
589 const char *backing_file
, const char *backing_fmt
,
590 QemuOpts
*opts
, Error
**errp
)
594 .cluster_size
= cluster_size
,
595 .table_size
= table_size
,
598 .compat_features
= 0,
599 .l1_table_offset
= cluster_size
,
600 .image_size
= image_size
,
603 uint8_t *l1_table
= NULL
;
604 size_t l1_size
= header
.cluster_size
* header
.table_size
;
605 Error
*local_err
= NULL
;
609 ret
= bdrv_create_file(filename
, opts
, &local_err
);
611 error_propagate(errp
, local_err
);
615 blk
= blk_new_open(filename
, NULL
, NULL
,
616 BDRV_O_RDWR
| BDRV_O_PROTOCOL
, &local_err
);
618 error_propagate(errp
, local_err
);
622 blk_set_allow_write_beyond_eof(blk
, true);
624 /* File must start empty and grow, check truncate is supported */
625 ret
= blk_truncate(blk
, 0);
631 header
.features
|= QED_F_BACKING_FILE
;
632 header
.backing_filename_offset
= sizeof(le_header
);
633 header
.backing_filename_size
= strlen(backing_file
);
635 if (qed_fmt_is_raw(backing_fmt
)) {
636 header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
640 qed_header_cpu_to_le(&header
, &le_header
);
641 ret
= blk_pwrite(blk
, 0, &le_header
, sizeof(le_header
), 0);
645 ret
= blk_pwrite(blk
, sizeof(le_header
), backing_file
,
646 header
.backing_filename_size
, 0);
651 l1_table
= g_malloc0(l1_size
);
652 ret
= blk_pwrite(blk
, header
.l1_table_offset
, l1_table
, l1_size
, 0);
657 ret
= 0; /* success */
664 static int bdrv_qed_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
666 uint64_t image_size
= 0;
667 uint32_t cluster_size
= QED_DEFAULT_CLUSTER_SIZE
;
668 uint32_t table_size
= QED_DEFAULT_TABLE_SIZE
;
669 char *backing_file
= NULL
;
670 char *backing_fmt
= NULL
;
673 image_size
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
675 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
676 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
677 cluster_size
= qemu_opt_get_size_del(opts
,
678 BLOCK_OPT_CLUSTER_SIZE
,
679 QED_DEFAULT_CLUSTER_SIZE
);
680 table_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_TABLE_SIZE
,
681 QED_DEFAULT_TABLE_SIZE
);
683 if (!qed_is_cluster_size_valid(cluster_size
)) {
684 error_setg(errp
, "QED cluster size must be within range [%u, %u] "
686 QED_MIN_CLUSTER_SIZE
, QED_MAX_CLUSTER_SIZE
);
690 if (!qed_is_table_size_valid(table_size
)) {
691 error_setg(errp
, "QED table size must be within range [%u, %u] "
693 QED_MIN_TABLE_SIZE
, QED_MAX_TABLE_SIZE
);
697 if (!qed_is_image_size_valid(image_size
, cluster_size
, table_size
)) {
698 error_setg(errp
, "QED image size must be a non-zero multiple of "
699 "cluster size and less than %" PRIu64
" bytes",
700 qed_max_image_size(cluster_size
, table_size
));
705 ret
= qed_create(filename
, cluster_size
, image_size
, table_size
,
706 backing_file
, backing_fmt
, opts
, errp
);
709 g_free(backing_file
);
715 BlockDriverState
*bs
;
720 BlockDriverState
**file
;
723 static void qed_is_allocated_cb(void *opaque
, int ret
, uint64_t offset
, size_t len
)
725 QEDIsAllocatedCB
*cb
= opaque
;
726 BDRVQEDState
*s
= cb
->bs
->opaque
;
727 *cb
->pnum
= len
/ BDRV_SECTOR_SIZE
;
729 case QED_CLUSTER_FOUND
:
730 offset
|= qed_offset_into_cluster(s
, cb
->pos
);
731 cb
->status
= BDRV_BLOCK_DATA
| BDRV_BLOCK_OFFSET_VALID
| offset
;
732 *cb
->file
= cb
->bs
->file
->bs
;
734 case QED_CLUSTER_ZERO
:
735 cb
->status
= BDRV_BLOCK_ZERO
;
752 static int64_t coroutine_fn
bdrv_qed_co_get_block_status(BlockDriverState
*bs
,
754 int nb_sectors
, int *pnum
,
755 BlockDriverState
**file
)
757 BDRVQEDState
*s
= bs
->opaque
;
758 size_t len
= (size_t)nb_sectors
* BDRV_SECTOR_SIZE
;
759 QEDIsAllocatedCB cb
= {
761 .pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
,
762 .status
= BDRV_BLOCK_OFFSET_MASK
,
766 QEDRequest request
= { .l2_table
= NULL
};
768 qed_find_cluster(s
, &request
, cb
.pos
, len
, qed_is_allocated_cb
, &cb
);
770 /* Now sleep if the callback wasn't invoked immediately */
771 while (cb
.status
== BDRV_BLOCK_OFFSET_MASK
) {
772 cb
.co
= qemu_coroutine_self();
773 qemu_coroutine_yield();
776 qed_unref_l2_cache_entry(request
.l2_table
);
781 static BDRVQEDState
*acb_to_s(QEDAIOCB
*acb
)
783 return acb
->common
.bs
->opaque
;
787 * Read from the backing file or zero-fill if no backing file
790 * @pos: Byte position in device
791 * @qiov: Destination I/O vector
792 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
793 * @cb: Completion function
794 * @opaque: User data for completion function
796 * This function reads qiov->size bytes starting at pos from the backing file.
797 * If there is no backing file then zeroes are read.
799 static void qed_read_backing_file(BDRVQEDState
*s
, uint64_t pos
,
801 QEMUIOVector
**backing_qiov
,
802 BlockCompletionFunc
*cb
, void *opaque
)
804 uint64_t backing_length
= 0;
807 /* If there is a backing file, get its length. Treat the absence of a
808 * backing file like a zero length backing file.
810 if (s
->bs
->backing
) {
811 int64_t l
= bdrv_getlength(s
->bs
->backing
->bs
);
819 /* Zero all sectors if reading beyond the end of the backing file */
820 if (pos
>= backing_length
||
821 pos
+ qiov
->size
> backing_length
) {
822 qemu_iovec_memset(qiov
, 0, 0, qiov
->size
);
825 /* Complete now if there are no backing file sectors to read */
826 if (pos
>= backing_length
) {
831 /* If the read straddles the end of the backing file, shorten it */
832 size
= MIN((uint64_t)backing_length
- pos
, qiov
->size
);
834 assert(*backing_qiov
== NULL
);
835 *backing_qiov
= g_new(QEMUIOVector
, 1);
836 qemu_iovec_init(*backing_qiov
, qiov
->niov
);
837 qemu_iovec_concat(*backing_qiov
, qiov
, 0, size
);
839 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_READ_BACKING_AIO
);
840 bdrv_aio_readv(s
->bs
->backing
, pos
/ BDRV_SECTOR_SIZE
,
841 *backing_qiov
, size
/ BDRV_SECTOR_SIZE
, cb
, opaque
);
848 QEMUIOVector
*backing_qiov
;
851 } CopyFromBackingFileCB
;
853 static void qed_copy_from_backing_file_cb(void *opaque
, int ret
)
855 CopyFromBackingFileCB
*copy_cb
= opaque
;
856 qemu_vfree(copy_cb
->iov
.iov_base
);
857 gencb_complete(©_cb
->gencb
, ret
);
860 static void qed_copy_from_backing_file_write(void *opaque
, int ret
)
862 CopyFromBackingFileCB
*copy_cb
= opaque
;
863 BDRVQEDState
*s
= copy_cb
->s
;
865 if (copy_cb
->backing_qiov
) {
866 qemu_iovec_destroy(copy_cb
->backing_qiov
);
867 g_free(copy_cb
->backing_qiov
);
868 copy_cb
->backing_qiov
= NULL
;
872 qed_copy_from_backing_file_cb(copy_cb
, ret
);
876 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_COW_WRITE
);
877 bdrv_aio_writev(s
->bs
->file
, copy_cb
->offset
/ BDRV_SECTOR_SIZE
,
878 ©_cb
->qiov
, copy_cb
->qiov
.size
/ BDRV_SECTOR_SIZE
,
879 qed_copy_from_backing_file_cb
, copy_cb
);
883 * Copy data from backing file into the image
886 * @pos: Byte position in device
887 * @len: Number of bytes
888 * @offset: Byte offset in image file
889 * @cb: Completion function
890 * @opaque: User data for completion function
892 static void qed_copy_from_backing_file(BDRVQEDState
*s
, uint64_t pos
,
893 uint64_t len
, uint64_t offset
,
894 BlockCompletionFunc
*cb
,
897 CopyFromBackingFileCB
*copy_cb
;
899 /* Skip copy entirely if there is no work to do */
905 copy_cb
= gencb_alloc(sizeof(*copy_cb
), cb
, opaque
);
907 copy_cb
->offset
= offset
;
908 copy_cb
->backing_qiov
= NULL
;
909 copy_cb
->iov
.iov_base
= qemu_blockalign(s
->bs
, len
);
910 copy_cb
->iov
.iov_len
= len
;
911 qemu_iovec_init_external(©_cb
->qiov
, ©_cb
->iov
, 1);
913 qed_read_backing_file(s
, pos
, ©_cb
->qiov
, ©_cb
->backing_qiov
,
914 qed_copy_from_backing_file_write
, copy_cb
);
918 * Link one or more contiguous clusters into a table
922 * @index: First cluster index
923 * @n: Number of contiguous clusters
924 * @cluster: First cluster offset
926 * The cluster offset may be an allocated byte offset in the image file, the
927 * zero cluster marker, or the unallocated cluster marker.
929 static void qed_update_l2_table(BDRVQEDState
*s
, QEDTable
*table
, int index
,
930 unsigned int n
, uint64_t cluster
)
933 for (i
= index
; i
< index
+ n
; i
++) {
934 table
->offsets
[i
] = cluster
;
935 if (!qed_offset_is_unalloc_cluster(cluster
) &&
936 !qed_offset_is_zero_cluster(cluster
)) {
937 cluster
+= s
->header
.cluster_size
;
942 static void qed_aio_complete_bh(void *opaque
)
944 QEDAIOCB
*acb
= opaque
;
945 BDRVQEDState
*s
= acb_to_s(acb
);
946 BlockCompletionFunc
*cb
= acb
->common
.cb
;
947 void *user_opaque
= acb
->common
.opaque
;
948 int ret
= acb
->bh_ret
;
952 /* Invoke callback */
954 cb(user_opaque
, ret
);
958 static void qed_aio_complete(QEDAIOCB
*acb
, int ret
)
960 BDRVQEDState
*s
= acb_to_s(acb
);
962 trace_qed_aio_complete(s
, acb
, ret
);
965 qemu_iovec_destroy(&acb
->cur_qiov
);
966 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
968 /* Free the buffer we may have allocated for zero writes */
969 if (acb
->flags
& QED_AIOCB_ZERO
) {
970 qemu_vfree(acb
->qiov
->iov
[0].iov_base
);
971 acb
->qiov
->iov
[0].iov_base
= NULL
;
974 /* Arrange for a bh to invoke the completion function */
976 aio_bh_schedule_oneshot(bdrv_get_aio_context(acb
->common
.bs
),
977 qed_aio_complete_bh
, acb
);
979 /* Start next allocating write request waiting behind this one. Note that
980 * requests enqueue themselves when they first hit an unallocated cluster
981 * but they wait until the entire request is finished before waking up the
982 * next request in the queue. This ensures that we don't cycle through
983 * requests multiple times but rather finish one at a time completely.
985 if (acb
== QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
986 QSIMPLEQ_REMOVE_HEAD(&s
->allocating_write_reqs
, next
);
987 acb
= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
);
989 qed_aio_start_io(acb
);
990 } else if (s
->header
.features
& QED_F_NEED_CHECK
) {
991 qed_start_need_check_timer(s
);
997 * Commit the current L2 table to the cache
999 static void qed_commit_l2_update(void *opaque
, int ret
)
1001 QEDAIOCB
*acb
= opaque
;
1002 BDRVQEDState
*s
= acb_to_s(acb
);
1003 CachedL2Table
*l2_table
= acb
->request
.l2_table
;
1004 uint64_t l2_offset
= l2_table
->offset
;
1006 qed_commit_l2_cache_entry(&s
->l2_cache
, l2_table
);
1008 /* This is guaranteed to succeed because we just committed the entry to the
1011 acb
->request
.l2_table
= qed_find_l2_cache_entry(&s
->l2_cache
, l2_offset
);
1012 assert(acb
->request
.l2_table
!= NULL
);
1014 qed_aio_next_io(acb
, ret
);
1018 * Update L1 table with new L2 table offset and write it out
1020 static void qed_aio_write_l1_update(void *opaque
, int ret
)
1022 QEDAIOCB
*acb
= opaque
;
1023 BDRVQEDState
*s
= acb_to_s(acb
);
1027 qed_aio_complete(acb
, ret
);
1031 index
= qed_l1_index(s
, acb
->cur_pos
);
1032 s
->l1_table
->offsets
[index
] = acb
->request
.l2_table
->offset
;
1034 qed_write_l1_table(s
, index
, 1, qed_commit_l2_update
, acb
);
1038 * Update L2 table with new cluster offsets and write them out
1040 static void qed_aio_write_l2_update(QEDAIOCB
*acb
, int ret
, uint64_t offset
)
1042 BDRVQEDState
*s
= acb_to_s(acb
);
1043 bool need_alloc
= acb
->find_cluster_ret
== QED_CLUSTER_L1
;
1051 qed_unref_l2_cache_entry(acb
->request
.l2_table
);
1052 acb
->request
.l2_table
= qed_new_l2_table(s
);
1055 index
= qed_l2_index(s
, acb
->cur_pos
);
1056 qed_update_l2_table(s
, acb
->request
.l2_table
->table
, index
, acb
->cur_nclusters
,
1060 /* Write out the whole new L2 table */
1061 qed_write_l2_table(s
, &acb
->request
, 0, s
->table_nelems
, true,
1062 qed_aio_write_l1_update
, acb
);
1064 /* Write out only the updated part of the L2 table */
1065 qed_write_l2_table(s
, &acb
->request
, index
, acb
->cur_nclusters
, false,
1066 qed_aio_next_io_cb
, acb
);
1071 qed_aio_complete(acb
, ret
);
1074 static void qed_aio_write_l2_update_cb(void *opaque
, int ret
)
1076 QEDAIOCB
*acb
= opaque
;
1077 qed_aio_write_l2_update(acb
, ret
, acb
->cur_cluster
);
1081 * Flush new data clusters before updating the L2 table
1083 * This flush is necessary when a backing file is in use. A crash during an
1084 * allocating write could result in empty clusters in the image. If the write
1085 * only touched a subregion of the cluster, then backing image sectors have
1086 * been lost in the untouched region. The solution is to flush after writing a
1087 * new data cluster and before updating the L2 table.
1089 static void qed_aio_write_flush_before_l2_update(void *opaque
, int ret
)
1091 QEDAIOCB
*acb
= opaque
;
1092 BDRVQEDState
*s
= acb_to_s(acb
);
1094 if (!bdrv_aio_flush(s
->bs
->file
->bs
, qed_aio_write_l2_update_cb
, opaque
)) {
1095 qed_aio_complete(acb
, -EIO
);
1100 * Write data to the image file
1102 static void qed_aio_write_main(void *opaque
, int ret
)
1104 QEDAIOCB
*acb
= opaque
;
1105 BDRVQEDState
*s
= acb_to_s(acb
);
1106 uint64_t offset
= acb
->cur_cluster
+
1107 qed_offset_into_cluster(s
, acb
->cur_pos
);
1108 BlockCompletionFunc
*next_fn
;
1110 trace_qed_aio_write_main(s
, acb
, ret
, offset
, acb
->cur_qiov
.size
);
1113 qed_aio_complete(acb
, ret
);
1117 if (acb
->find_cluster_ret
== QED_CLUSTER_FOUND
) {
1118 next_fn
= qed_aio_next_io_cb
;
1120 if (s
->bs
->backing
) {
1121 next_fn
= qed_aio_write_flush_before_l2_update
;
1123 next_fn
= qed_aio_write_l2_update_cb
;
1127 BLKDBG_EVENT(s
->bs
->file
, BLKDBG_WRITE_AIO
);
1128 bdrv_aio_writev(s
->bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1129 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1134 * Populate back untouched region of new data cluster
1136 static void qed_aio_write_postfill(void *opaque
, int ret
)
1138 QEDAIOCB
*acb
= opaque
;
1139 BDRVQEDState
*s
= acb_to_s(acb
);
1140 uint64_t start
= acb
->cur_pos
+ acb
->cur_qiov
.size
;
1142 qed_start_of_cluster(s
, start
+ s
->header
.cluster_size
- 1) - start
;
1143 uint64_t offset
= acb
->cur_cluster
+
1144 qed_offset_into_cluster(s
, acb
->cur_pos
) +
1148 qed_aio_complete(acb
, ret
);
1152 trace_qed_aio_write_postfill(s
, acb
, start
, len
, offset
);
1153 qed_copy_from_backing_file(s
, start
, len
, offset
,
1154 qed_aio_write_main
, acb
);
1158 * Populate front untouched region of new data cluster
1160 static void qed_aio_write_prefill(void *opaque
, int ret
)
1162 QEDAIOCB
*acb
= opaque
;
1163 BDRVQEDState
*s
= acb_to_s(acb
);
1164 uint64_t start
= qed_start_of_cluster(s
, acb
->cur_pos
);
1165 uint64_t len
= qed_offset_into_cluster(s
, acb
->cur_pos
);
1167 trace_qed_aio_write_prefill(s
, acb
, start
, len
, acb
->cur_cluster
);
1168 qed_copy_from_backing_file(s
, start
, len
, acb
->cur_cluster
,
1169 qed_aio_write_postfill
, acb
);
1173 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1175 static bool qed_should_set_need_check(BDRVQEDState
*s
)
1177 /* The flush before L2 update path ensures consistency */
1178 if (s
->bs
->backing
) {
1182 return !(s
->header
.features
& QED_F_NEED_CHECK
);
1185 static void qed_aio_write_zero_cluster(void *opaque
, int ret
)
1187 QEDAIOCB
*acb
= opaque
;
1190 qed_aio_complete(acb
, ret
);
1194 qed_aio_write_l2_update(acb
, 0, 1);
1198 * Write new data cluster
1200 * @acb: Write request
1201 * @len: Length in bytes
1203 * This path is taken when writing to previously unallocated clusters.
1205 static void qed_aio_write_alloc(QEDAIOCB
*acb
, size_t len
)
1207 BDRVQEDState
*s
= acb_to_s(acb
);
1208 BlockCompletionFunc
*cb
;
1210 /* Cancel timer when the first allocating request comes in */
1211 if (QSIMPLEQ_EMPTY(&s
->allocating_write_reqs
)) {
1212 qed_cancel_need_check_timer(s
);
1215 /* Freeze this request if another allocating write is in progress */
1216 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
)) {
1217 QSIMPLEQ_INSERT_TAIL(&s
->allocating_write_reqs
, acb
, next
);
1219 if (acb
!= QSIMPLEQ_FIRST(&s
->allocating_write_reqs
) ||
1220 s
->allocating_write_reqs_plugged
) {
1221 return; /* wait for existing request to finish */
1224 acb
->cur_nclusters
= qed_bytes_to_clusters(s
,
1225 qed_offset_into_cluster(s
, acb
->cur_pos
) + len
);
1226 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1228 if (acb
->flags
& QED_AIOCB_ZERO
) {
1229 /* Skip ahead if the clusters are already zero */
1230 if (acb
->find_cluster_ret
== QED_CLUSTER_ZERO
) {
1231 qed_aio_start_io(acb
);
1235 cb
= qed_aio_write_zero_cluster
;
1237 cb
= qed_aio_write_prefill
;
1238 acb
->cur_cluster
= qed_alloc_clusters(s
, acb
->cur_nclusters
);
1241 if (qed_should_set_need_check(s
)) {
1242 s
->header
.features
|= QED_F_NEED_CHECK
;
1243 qed_write_header(s
, cb
, acb
);
1250 * Write data cluster in place
1252 * @acb: Write request
1253 * @offset: Cluster offset in bytes
1254 * @len: Length in bytes
1256 * This path is taken when writing to already allocated clusters.
1258 static void qed_aio_write_inplace(QEDAIOCB
*acb
, uint64_t offset
, size_t len
)
1260 /* Allocate buffer for zero writes */
1261 if (acb
->flags
& QED_AIOCB_ZERO
) {
1262 struct iovec
*iov
= acb
->qiov
->iov
;
1264 if (!iov
->iov_base
) {
1265 iov
->iov_base
= qemu_try_blockalign(acb
->common
.bs
, iov
->iov_len
);
1266 if (iov
->iov_base
== NULL
) {
1267 qed_aio_complete(acb
, -ENOMEM
);
1270 memset(iov
->iov_base
, 0, iov
->iov_len
);
1274 /* Calculate the I/O vector */
1275 acb
->cur_cluster
= offset
;
1276 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1278 /* Do the actual write */
1279 qed_aio_write_main(acb
, 0);
1283 * Write data cluster
1285 * @opaque: Write request
1286 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1288 * @offset: Cluster offset in bytes
1289 * @len: Length in bytes
1291 * Callback from qed_find_cluster().
1293 static void qed_aio_write_data(void *opaque
, int ret
,
1294 uint64_t offset
, size_t len
)
1296 QEDAIOCB
*acb
= opaque
;
1298 trace_qed_aio_write_data(acb_to_s(acb
), acb
, ret
, offset
, len
);
1300 acb
->find_cluster_ret
= ret
;
1303 case QED_CLUSTER_FOUND
:
1304 qed_aio_write_inplace(acb
, offset
, len
);
1307 case QED_CLUSTER_L2
:
1308 case QED_CLUSTER_L1
:
1309 case QED_CLUSTER_ZERO
:
1310 qed_aio_write_alloc(acb
, len
);
1314 qed_aio_complete(acb
, ret
);
1322 * @opaque: Read request
1323 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
1325 * @offset: Cluster offset in bytes
1326 * @len: Length in bytes
1328 * Callback from qed_find_cluster().
1330 static void qed_aio_read_data(void *opaque
, int ret
,
1331 uint64_t offset
, size_t len
)
1333 QEDAIOCB
*acb
= opaque
;
1334 BDRVQEDState
*s
= acb_to_s(acb
);
1335 BlockDriverState
*bs
= acb
->common
.bs
;
1337 /* Adjust offset into cluster */
1338 offset
+= qed_offset_into_cluster(s
, acb
->cur_pos
);
1340 trace_qed_aio_read_data(s
, acb
, ret
, offset
, len
);
1346 qemu_iovec_concat(&acb
->cur_qiov
, acb
->qiov
, acb
->qiov_offset
, len
);
1348 /* Handle zero cluster and backing file reads */
1349 if (ret
== QED_CLUSTER_ZERO
) {
1350 qemu_iovec_memset(&acb
->cur_qiov
, 0, 0, acb
->cur_qiov
.size
);
1351 qed_aio_start_io(acb
);
1353 } else if (ret
!= QED_CLUSTER_FOUND
) {
1354 qed_read_backing_file(s
, acb
->cur_pos
, &acb
->cur_qiov
,
1355 &acb
->backing_qiov
, qed_aio_next_io_cb
, acb
);
1359 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1360 bdrv_aio_readv(bs
->file
, offset
/ BDRV_SECTOR_SIZE
,
1361 &acb
->cur_qiov
, acb
->cur_qiov
.size
/ BDRV_SECTOR_SIZE
,
1362 qed_aio_next_io_cb
, acb
);
1366 qed_aio_complete(acb
, ret
);
1370 * Begin next I/O or complete the request
1372 static void qed_aio_next_io(QEDAIOCB
*acb
, int ret
)
1374 BDRVQEDState
*s
= acb_to_s(acb
);
1375 QEDFindClusterFunc
*io_fn
= (acb
->flags
& QED_AIOCB_WRITE
) ?
1376 qed_aio_write_data
: qed_aio_read_data
;
1378 trace_qed_aio_next_io(s
, acb
, ret
, acb
->cur_pos
+ acb
->cur_qiov
.size
);
1380 if (acb
->backing_qiov
) {
1381 qemu_iovec_destroy(acb
->backing_qiov
);
1382 g_free(acb
->backing_qiov
);
1383 acb
->backing_qiov
= NULL
;
1386 /* Handle I/O error */
1388 qed_aio_complete(acb
, ret
);
1392 acb
->qiov_offset
+= acb
->cur_qiov
.size
;
1393 acb
->cur_pos
+= acb
->cur_qiov
.size
;
1394 qemu_iovec_reset(&acb
->cur_qiov
);
1396 /* Complete request */
1397 if (acb
->cur_pos
>= acb
->end_pos
) {
1398 qed_aio_complete(acb
, 0);
1402 /* Find next cluster and start I/O */
1403 qed_find_cluster(s
, &acb
->request
,
1404 acb
->cur_pos
, acb
->end_pos
- acb
->cur_pos
,
1408 static BlockAIOCB
*qed_aio_setup(BlockDriverState
*bs
,
1410 QEMUIOVector
*qiov
, int nb_sectors
,
1411 BlockCompletionFunc
*cb
,
1412 void *opaque
, int flags
)
1414 QEDAIOCB
*acb
= qemu_aio_get(&qed_aiocb_info
, bs
, cb
, opaque
);
1416 trace_qed_aio_setup(bs
->opaque
, acb
, sector_num
, nb_sectors
,
1421 acb
->qiov_offset
= 0;
1422 acb
->cur_pos
= (uint64_t)sector_num
* BDRV_SECTOR_SIZE
;
1423 acb
->end_pos
= acb
->cur_pos
+ nb_sectors
* BDRV_SECTOR_SIZE
;
1424 acb
->backing_qiov
= NULL
;
1425 acb
->request
.l2_table
= NULL
;
1426 qemu_iovec_init(&acb
->cur_qiov
, qiov
->niov
);
1429 qed_aio_start_io(acb
);
1430 return &acb
->common
;
1433 static BlockAIOCB
*bdrv_qed_aio_readv(BlockDriverState
*bs
,
1435 QEMUIOVector
*qiov
, int nb_sectors
,
1436 BlockCompletionFunc
*cb
,
1439 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
, opaque
, 0);
1442 static BlockAIOCB
*bdrv_qed_aio_writev(BlockDriverState
*bs
,
1444 QEMUIOVector
*qiov
, int nb_sectors
,
1445 BlockCompletionFunc
*cb
,
1448 return qed_aio_setup(bs
, sector_num
, qiov
, nb_sectors
, cb
,
1449 opaque
, QED_AIOCB_WRITE
);
1458 static void coroutine_fn
qed_co_pwrite_zeroes_cb(void *opaque
, int ret
)
1460 QEDWriteZeroesCB
*cb
= opaque
;
1465 aio_co_wake(cb
->co
);
1469 static int coroutine_fn
bdrv_qed_co_pwrite_zeroes(BlockDriverState
*bs
,
1472 BdrvRequestFlags flags
)
1474 BlockAIOCB
*blockacb
;
1475 BDRVQEDState
*s
= bs
->opaque
;
1476 QEDWriteZeroesCB cb
= { .done
= false };
1480 /* Fall back if the request is not aligned */
1481 if (qed_offset_into_cluster(s
, offset
) ||
1482 qed_offset_into_cluster(s
, count
)) {
1486 /* Zero writes start without an I/O buffer. If a buffer becomes necessary
1487 * then it will be allocated during request processing.
1489 iov
.iov_base
= NULL
;
1490 iov
.iov_len
= count
;
1492 qemu_iovec_init_external(&qiov
, &iov
, 1);
1493 blockacb
= qed_aio_setup(bs
, offset
>> BDRV_SECTOR_BITS
, &qiov
,
1494 count
>> BDRV_SECTOR_BITS
,
1495 qed_co_pwrite_zeroes_cb
, &cb
,
1496 QED_AIOCB_WRITE
| QED_AIOCB_ZERO
);
1501 cb
.co
= qemu_coroutine_self();
1502 qemu_coroutine_yield();
1508 static int bdrv_qed_truncate(BlockDriverState
*bs
, int64_t offset
)
1510 BDRVQEDState
*s
= bs
->opaque
;
1511 uint64_t old_image_size
;
1514 if (!qed_is_image_size_valid(offset
, s
->header
.cluster_size
,
1515 s
->header
.table_size
)) {
1519 /* Shrinking is currently not supported */
1520 if ((uint64_t)offset
< s
->header
.image_size
) {
1524 old_image_size
= s
->header
.image_size
;
1525 s
->header
.image_size
= offset
;
1526 ret
= qed_write_header_sync(s
);
1528 s
->header
.image_size
= old_image_size
;
1533 static int64_t bdrv_qed_getlength(BlockDriverState
*bs
)
1535 BDRVQEDState
*s
= bs
->opaque
;
1536 return s
->header
.image_size
;
1539 static int bdrv_qed_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1541 BDRVQEDState
*s
= bs
->opaque
;
1543 memset(bdi
, 0, sizeof(*bdi
));
1544 bdi
->cluster_size
= s
->header
.cluster_size
;
1545 bdi
->is_dirty
= s
->header
.features
& QED_F_NEED_CHECK
;
1546 bdi
->unallocated_blocks_are_zero
= true;
1547 bdi
->can_write_zeroes_with_unmap
= true;
1551 static int bdrv_qed_change_backing_file(BlockDriverState
*bs
,
1552 const char *backing_file
,
1553 const char *backing_fmt
)
1555 BDRVQEDState
*s
= bs
->opaque
;
1556 QEDHeader new_header
, le_header
;
1558 size_t buffer_len
, backing_file_len
;
1561 /* Refuse to set backing filename if unknown compat feature bits are
1562 * active. If the image uses an unknown compat feature then we may not
1563 * know the layout of data following the header structure and cannot safely
1566 if (backing_file
&& (s
->header
.compat_features
&
1567 ~QED_COMPAT_FEATURE_MASK
)) {
1571 memcpy(&new_header
, &s
->header
, sizeof(new_header
));
1573 new_header
.features
&= ~(QED_F_BACKING_FILE
|
1574 QED_F_BACKING_FORMAT_NO_PROBE
);
1576 /* Adjust feature flags */
1578 new_header
.features
|= QED_F_BACKING_FILE
;
1580 if (qed_fmt_is_raw(backing_fmt
)) {
1581 new_header
.features
|= QED_F_BACKING_FORMAT_NO_PROBE
;
1585 /* Calculate new header size */
1586 backing_file_len
= 0;
1589 backing_file_len
= strlen(backing_file
);
1592 buffer_len
= sizeof(new_header
);
1593 new_header
.backing_filename_offset
= buffer_len
;
1594 new_header
.backing_filename_size
= backing_file_len
;
1595 buffer_len
+= backing_file_len
;
1597 /* Make sure we can rewrite header without failing */
1598 if (buffer_len
> new_header
.header_size
* new_header
.cluster_size
) {
1602 /* Prepare new header */
1603 buffer
= g_malloc(buffer_len
);
1605 qed_header_cpu_to_le(&new_header
, &le_header
);
1606 memcpy(buffer
, &le_header
, sizeof(le_header
));
1607 buffer_len
= sizeof(le_header
);
1610 memcpy(buffer
+ buffer_len
, backing_file
, backing_file_len
);
1611 buffer_len
+= backing_file_len
;
1614 /* Write new header */
1615 ret
= bdrv_pwrite_sync(bs
->file
, 0, buffer
, buffer_len
);
1618 memcpy(&s
->header
, &new_header
, sizeof(new_header
));
1623 static void bdrv_qed_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
1625 BDRVQEDState
*s
= bs
->opaque
;
1626 Error
*local_err
= NULL
;
1631 memset(s
, 0, sizeof(BDRVQEDState
));
1632 ret
= bdrv_qed_open(bs
, NULL
, bs
->open_flags
, &local_err
);
1634 error_propagate(errp
, local_err
);
1635 error_prepend(errp
, "Could not reopen qed layer: ");
1637 } else if (ret
< 0) {
1638 error_setg_errno(errp
, -ret
, "Could not reopen qed layer");
1643 static int bdrv_qed_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
1646 BDRVQEDState
*s
= bs
->opaque
;
1648 return qed_check(s
, result
, !!fix
);
1651 static QemuOptsList qed_create_opts
= {
1652 .name
= "qed-create-opts",
1653 .head
= QTAILQ_HEAD_INITIALIZER(qed_create_opts
.head
),
1656 .name
= BLOCK_OPT_SIZE
,
1657 .type
= QEMU_OPT_SIZE
,
1658 .help
= "Virtual disk size"
1661 .name
= BLOCK_OPT_BACKING_FILE
,
1662 .type
= QEMU_OPT_STRING
,
1663 .help
= "File name of a base image"
1666 .name
= BLOCK_OPT_BACKING_FMT
,
1667 .type
= QEMU_OPT_STRING
,
1668 .help
= "Image format of the base image"
1671 .name
= BLOCK_OPT_CLUSTER_SIZE
,
1672 .type
= QEMU_OPT_SIZE
,
1673 .help
= "Cluster size (in bytes)",
1674 .def_value_str
= stringify(QED_DEFAULT_CLUSTER_SIZE
)
1677 .name
= BLOCK_OPT_TABLE_SIZE
,
1678 .type
= QEMU_OPT_SIZE
,
1679 .help
= "L1/L2 table size (in clusters)"
1681 { /* end of list */ }
1685 static BlockDriver bdrv_qed
= {
1686 .format_name
= "qed",
1687 .instance_size
= sizeof(BDRVQEDState
),
1688 .create_opts
= &qed_create_opts
,
1689 .supports_backing
= true,
1691 .bdrv_probe
= bdrv_qed_probe
,
1692 .bdrv_open
= bdrv_qed_open
,
1693 .bdrv_close
= bdrv_qed_close
,
1694 .bdrv_reopen_prepare
= bdrv_qed_reopen_prepare
,
1695 .bdrv_create
= bdrv_qed_create
,
1696 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
1697 .bdrv_co_get_block_status
= bdrv_qed_co_get_block_status
,
1698 .bdrv_aio_readv
= bdrv_qed_aio_readv
,
1699 .bdrv_aio_writev
= bdrv_qed_aio_writev
,
1700 .bdrv_co_pwrite_zeroes
= bdrv_qed_co_pwrite_zeroes
,
1701 .bdrv_truncate
= bdrv_qed_truncate
,
1702 .bdrv_getlength
= bdrv_qed_getlength
,
1703 .bdrv_get_info
= bdrv_qed_get_info
,
1704 .bdrv_refresh_limits
= bdrv_qed_refresh_limits
,
1705 .bdrv_change_backing_file
= bdrv_qed_change_backing_file
,
1706 .bdrv_invalidate_cache
= bdrv_qed_invalidate_cache
,
1707 .bdrv_check
= bdrv_qed_check
,
1708 .bdrv_detach_aio_context
= bdrv_qed_detach_aio_context
,
1709 .bdrv_attach_aio_context
= bdrv_qed_attach_aio_context
,
1710 .bdrv_drain
= bdrv_qed_drain
,
1713 static void bdrv_qed_init(void)
1715 bdrv_register(&bdrv_qed
);
1718 block_init(bdrv_qed_init
);