1/*
2 * QEMU Enhanced Disk Format
3 *
4 * Copyright IBM, Corp. 2010
5 *
6 * Authors:
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
8 * Anthony Liguori <aliguori@us.ibm.com>
9 *
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.
12 *
13 */
14
15#include "qemu/osdep.h"
16#include "block/qdict.h"
17#include "qapi/error.h"
18#include "qemu/timer.h"
19#include "qemu/bswap.h"
20#include "qemu/main-loop.h"
21#include "qemu/module.h"
22#include "qemu/option.h"
23#include "trace.h"
24#include "qed.h"
25#include "sysemu/block-backend.h"
26#include "qapi/qmp/qdict.h"
27#include "qapi/qobject-input-visitor.h"
28#include "qapi/qapi-visit-block-core.h"
29
30static QemuOptsList qed_create_opts;
31
32static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
33 const char *filename)
34{
35 const QEDHeader *header = (const QEDHeader *)buf;
36
37 if (buf_size < sizeof(*header)) {
38 return 0;
39 }
40 if (le32_to_cpu(header->magic) != QED_MAGIC) {
41 return 0;
42 }
43 return 100;
44}
45
46/**
47 * Check whether an image format is raw
48 *
49 * @fmt: Backing file format, may be NULL
50 */
51static bool qed_fmt_is_raw(const char *fmt)
52{
53 return fmt && strcmp(fmt, "raw") == 0;
54}
55
56static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu)
57{
58 cpu->magic = le32_to_cpu(le->magic);
59 cpu->cluster_size = le32_to_cpu(le->cluster_size);
60 cpu->table_size = le32_to_cpu(le->table_size);
61 cpu->header_size = le32_to_cpu(le->header_size);
62 cpu->features = le64_to_cpu(le->features);
63 cpu->compat_features = le64_to_cpu(le->compat_features);
64 cpu->autoclear_features = le64_to_cpu(le->autoclear_features);
65 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset);
66 cpu->image_size = le64_to_cpu(le->image_size);
67 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset);
68 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size);
69}
70
71static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
72{
73 le->magic = cpu_to_le32(cpu->magic);
74 le->cluster_size = cpu_to_le32(cpu->cluster_size);
75 le->table_size = cpu_to_le32(cpu->table_size);
76 le->header_size = cpu_to_le32(cpu->header_size);
77 le->features = cpu_to_le64(cpu->features);
78 le->compat_features = cpu_to_le64(cpu->compat_features);
79 le->autoclear_features = cpu_to_le64(cpu->autoclear_features);
80 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset);
81 le->image_size = cpu_to_le64(cpu->image_size);
82 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset);
83 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size);
84}
85
86int qed_write_header_sync(BDRVQEDState *s)
87{
88 QEDHeader le;
89 int ret;
90
91 qed_header_cpu_to_le(&s->header, &le);
92 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le));
93 if (ret != sizeof(le)) {
94 return ret;
95 }
96 return 0;
97}
98
99/**
100 * Update header in-place (does not rewrite backing filename or other strings)
101 *
102 * This function only updates known header fields in-place and does not affect
103 * extra data after the QED header.
104 *
105 * No new allocating reqs can start while this function runs.
106 */
107static int coroutine_fn qed_write_header(BDRVQEDState *s)
108{
109 /* We must write full sectors for O_DIRECT but cannot necessarily generate
110 * the data following the header if an unrecognized compat feature is
111 * active. Therefore, first read the sectors containing the header, update
112 * them, and write back.
113 */
114
115 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE);
116 size_t len = nsectors * BDRV_SECTOR_SIZE;
117 uint8_t *buf;
118 int ret;
119
120 assert(s->allocating_acb || s->allocating_write_reqs_plugged);
121
122 buf = qemu_blockalign(s->bs, len);
123
124 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0);
125 if (ret < 0) {
126 goto out;
127 }
128
129 /* Update header */
130 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf);
131
132 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0);
133 if (ret < 0) {
134 goto out;
135 }
136
137 ret = 0;
138out:
139 qemu_vfree(buf);
140 return ret;
141}
142
143static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
144{
145 uint64_t table_entries;
146 uint64_t l2_size;
147
148 table_entries = (table_size * cluster_size) / sizeof(uint64_t);
149 l2_size = table_entries * cluster_size;
150
151 return l2_size * table_entries;
152}
153
154static bool qed_is_cluster_size_valid(uint32_t cluster_size)
155{
156 if (cluster_size < QED_MIN_CLUSTER_SIZE ||
157 cluster_size > QED_MAX_CLUSTER_SIZE) {
158 return false;
159 }
160 if (cluster_size & (cluster_size - 1)) {
161 return false; /* not power of 2 */
162 }
163 return true;
164}
165
166static bool qed_is_table_size_valid(uint32_t table_size)
167{
168 if (table_size < QED_MIN_TABLE_SIZE ||
169 table_size > QED_MAX_TABLE_SIZE) {
170 return false;
171 }
172 if (table_size & (table_size - 1)) {
173 return false; /* not power of 2 */
174 }
175 return true;
176}
177
178static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size,
179 uint32_t table_size)
180{
181 if (image_size % BDRV_SECTOR_SIZE != 0) {
182 return false; /* not multiple of sector size */
183 }
184 if (image_size > qed_max_image_size(cluster_size, table_size)) {
185 return false; /* image is too large */
186 }
187 return true;
188}
189
190/**
191 * Read a string of known length from the image file
192 *
193 * @file: Image file
194 * @offset: File offset to start of string, in bytes
195 * @n: String length in bytes
196 * @buf: Destination buffer
197 * @buflen: Destination buffer length in bytes
198 * @ret: 0 on success, -errno on failure
199 *
200 * The string is NUL-terminated.
201 */
202static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n,
203 char *buf, size_t buflen)
204{
205 int ret;
206 if (n >= buflen) {
207 return -EINVAL;
208 }
209 ret = bdrv_pread(file, offset, buf, n);
210 if (ret < 0) {
211 return ret;
212 }
213 buf[n] = '\0';
214 return 0;
215}
216
217/**
218 * Allocate new clusters
219 *
220 * @s: QED state
221 * @n: Number of contiguous clusters to allocate
222 * @ret: Offset of first allocated cluster
223 *
224 * This function only produces the offset where the new clusters should be
225 * written. It updates BDRVQEDState but does not make any changes to the image
226 * file.
227 *
228 * Called with table_lock held.
229 */
230static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n)
231{
232 uint64_t offset = s->file_size;
233 s->file_size += n * s->header.cluster_size;
234 return offset;
235}
236
237QEDTable *qed_alloc_table(BDRVQEDState *s)
238{
239 /* Honor O_DIRECT memory alignment requirements */
240 return qemu_blockalign(s->bs,
241 s->header.cluster_size * s->header.table_size);
242}
243
244/**
245 * Allocate a new zeroed L2 table
246 *
247 * Called with table_lock held.
248 */
249static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
250{
251 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
252
253 l2_table->table = qed_alloc_table(s);
254 l2_table->offset = qed_alloc_clusters(s, s->header.table_size);
255
256 memset(l2_table->table->offsets, 0,
257 s->header.cluster_size * s->header.table_size);
258 return l2_table;
259}
260
261static bool qed_plug_allocating_write_reqs(BDRVQEDState *s)
262{
263 qemu_co_mutex_lock(&s->table_lock);
264
265 /* No reentrancy is allowed. */
266 assert(!s->allocating_write_reqs_plugged);
267 if (s->allocating_acb != NULL) {
268 /* Another allocating write came concurrently. This cannot happen
269 * from bdrv_qed_co_drain_begin, but it can happen when the timer runs.
270 */
271 qemu_co_mutex_unlock(&s->table_lock);
272 return false;
273 }
274
275 s->allocating_write_reqs_plugged = true;
276 qemu_co_mutex_unlock(&s->table_lock);
277 return true;
278}
279
280static void qed_unplug_allocating_write_reqs(BDRVQEDState *s)
281{
282 qemu_co_mutex_lock(&s->table_lock);
283 assert(s->allocating_write_reqs_plugged);
284 s->allocating_write_reqs_plugged = false;
285 qemu_co_queue_next(&s->allocating_write_reqs);
286 qemu_co_mutex_unlock(&s->table_lock);
287}
288
289static void coroutine_fn qed_need_check_timer_entry(void *opaque)
290{
291 BDRVQEDState *s = opaque;
292 int ret;
293
294 trace_qed_need_check_timer_cb(s);
295
296 if (!qed_plug_allocating_write_reqs(s)) {
297 return;
298 }
299
300 /* Ensure writes are on disk before clearing flag */
301 ret = bdrv_co_flush(s->bs->file->bs);
302 if (ret < 0) {
303 qed_unplug_allocating_write_reqs(s);
304 return;
305 }
306
307 s->header.features &= ~QED_F_NEED_CHECK;
308 ret = qed_write_header(s);
309 (void) ret;
310
311 qed_unplug_allocating_write_reqs(s);
312
313 ret = bdrv_co_flush(s->bs);
314 (void) ret;
315}
316
317static void qed_need_check_timer_cb(void *opaque)
318{
319 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque);
320 qemu_coroutine_enter(co);
321}
322
323static void qed_start_need_check_timer(BDRVQEDState *s)
324{
325 trace_qed_start_need_check_timer(s);
326
327 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
328 * migration.
329 */
330 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
331 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT);
332}
333
334/* It's okay to call this multiple times or when no timer is started */
335static void qed_cancel_need_check_timer(BDRVQEDState *s)
336{
337 trace_qed_cancel_need_check_timer(s);
338 timer_del(s->need_check_timer);
339}
340
341static void bdrv_qed_detach_aio_context(BlockDriverState *bs)
342{
343 BDRVQEDState *s = bs->opaque;
344
345 qed_cancel_need_check_timer(s);
346 timer_free(s->need_check_timer);
347}
348
349static void bdrv_qed_attach_aio_context(BlockDriverState *bs,
350 AioContext *new_context)
351{
352 BDRVQEDState *s = bs->opaque;
353
354 s->need_check_timer = aio_timer_new(new_context,
355 QEMU_CLOCK_VIRTUAL, SCALE_NS,
356 qed_need_check_timer_cb, s);
357 if (s->header.features & QED_F_NEED_CHECK) {
358 qed_start_need_check_timer(s);
359 }
360}
361
362static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs)
363{
364 BDRVQEDState *s = bs->opaque;
365
366 /* Fire the timer immediately in order to start doing I/O as soon as the
367 * header is flushed.
368 */
369 if (s->need_check_timer && timer_pending(s->need_check_timer)) {
370 qed_cancel_need_check_timer(s);
371 qed_need_check_timer_entry(s);
372 }
373}
374
375static void bdrv_qed_init_state(BlockDriverState *bs)
376{
377 BDRVQEDState *s = bs->opaque;
378
379 memset(s, 0, sizeof(BDRVQEDState));
380 s->bs = bs;
381 qemu_co_mutex_init(&s->table_lock);
382 qemu_co_queue_init(&s->allocating_write_reqs);
383}
384
385/* Called with table_lock held. */
386static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options,
387 int flags, Error **errp)
388{
389 BDRVQEDState *s = bs->opaque;
390 QEDHeader le_header;
391 int64_t file_size;
392 int ret;
393
394 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header));
395 if (ret < 0) {
396 return ret;
397 }
398 qed_header_le_to_cpu(&le_header, &s->header);
399
400 if (s->header.magic != QED_MAGIC) {
401 error_setg(errp, "Image not in QED format");
402 return -EINVAL;
403 }
404 if (s->header.features & ~QED_FEATURE_MASK) {
405 /* image uses unsupported feature bits */
406 error_setg(errp, "Unsupported QED features: %" PRIx64,
407 s->header.features & ~QED_FEATURE_MASK);
408 return -ENOTSUP;
409 }
410 if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
411 return -EINVAL;
412 }
413
414 /* Round down file size to the last cluster */
415 file_size = bdrv_getlength(bs->file->bs);
416 if (file_size < 0) {
417 return file_size;
418 }
419 s->file_size = qed_start_of_cluster(s, file_size);
420
421 if (!qed_is_table_size_valid(s->header.table_size)) {
422 return -EINVAL;
423 }
424 if (!qed_is_image_size_valid(s->header.image_size,
425 s->header.cluster_size,
426 s->header.table_size)) {
427 return -EINVAL;
428 }
429 if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
430 return -EINVAL;
431 }
432
433 s->table_nelems = (s->header.cluster_size * s->header.table_size) /
434 sizeof(uint64_t);
435 s->l2_shift = ctz32(s->header.cluster_size);
436 s->l2_mask = s->table_nelems - 1;
437 s->l1_shift = s->l2_shift + ctz32(s->table_nelems);
438
439 /* Header size calculation must not overflow uint32_t */
440 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) {
441 return -EINVAL;
442 }
443
444 if ((s->header.features & QED_F_BACKING_FILE)) {
445 if ((uint64_t)s->header.backing_filename_offset +
446 s->header.backing_filename_size >
447 s->header.cluster_size * s->header.header_size) {
448 return -EINVAL;
449 }
450
451 ret = qed_read_string(bs->file, s->header.backing_filename_offset,
452 s->header.backing_filename_size,
453 bs->auto_backing_file,
454 sizeof(bs->auto_backing_file));
455 if (ret < 0) {
456 return ret;
457 }
458 pstrcpy(bs->backing_file, sizeof(bs->backing_file),
459 bs->auto_backing_file);
460
461 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
462 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
463 }
464 }
465
466 /* Reset unknown autoclear feature bits. This is a backwards
467 * compatibility mechanism that allows images to be opened by older
468 * programs, which "knock out" unknown feature bits. When an image is
469 * opened by a newer program again it can detect that the autoclear
470 * feature is no longer valid.
471 */
472 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 &&
473 !bdrv_is_read_only(bs->file->bs) && !(flags & BDRV_O_INACTIVE)) {
474 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK;
475
476 ret = qed_write_header_sync(s);
477 if (ret) {
478 return ret;
479 }
480
481 /* From here on only known autoclear feature bits are valid */
482 bdrv_flush(bs->file->bs);
483 }
484
485 s->l1_table = qed_alloc_table(s);
486 qed_init_l2_cache(&s->l2_cache);
487
488 ret = qed_read_l1_table_sync(s);
489 if (ret) {
490 goto out;
491 }
492
493 /* If image was not closed cleanly, check consistency */
494 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) {
495 /* Read-only images cannot be fixed. There is no risk of corruption
496 * since write operations are not possible. Therefore, allow
497 * potentially inconsistent images to be opened read-only. This can
498 * aid data recovery from an otherwise inconsistent image.
499 */
500 if (!bdrv_is_read_only(bs->file->bs) &&
501 !(flags & BDRV_O_INACTIVE)) {
502 BdrvCheckResult result = {0};
503
504 ret = qed_check(s, &result, true);
505 if (ret) {
506 goto out;
507 }
508 }
509 }
510
511 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs));
512
513out:
514 if (ret) {
515 qed_free_l2_cache(&s->l2_cache);
516 qemu_vfree(s->l1_table);
517 }
518 return ret;
519}
520
521typedef struct QEDOpenCo {
522 BlockDriverState *bs;
523 QDict *options;
524 int flags;
525 Error **errp;
526 int ret;
527} QEDOpenCo;
528
529static void coroutine_fn bdrv_qed_open_entry(void *opaque)
530{
531 QEDOpenCo *qoc = opaque;
532 BDRVQEDState *s = qoc->bs->opaque;
533
534 qemu_co_mutex_lock(&s->table_lock);
535 qoc->ret = bdrv_qed_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp);
536 qemu_co_mutex_unlock(&s->table_lock);
537}
538
539static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
540 Error **errp)
541{
542 QEDOpenCo qoc = {
543 .bs = bs,
544 .options = options,
545 .flags = flags,
546 .errp = errp,
547 .ret = -EINPROGRESS
548 };
549
550 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
551 false, errp);
552 if (!bs->file) {
553 return -EINVAL;
554 }
555
556 bdrv_qed_init_state(bs);
557 if (qemu_in_coroutine()) {
558 bdrv_qed_open_entry(&qoc);
559 } else {
560 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
561 qemu_coroutine_enter(qemu_coroutine_create(bdrv_qed_open_entry, &qoc));
562 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS);
563 }
564 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS);
565 return qoc.ret;
566}
567
568static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp)
569{
570 BDRVQEDState *s = bs->opaque;
571
572 bs->bl.pwrite_zeroes_alignment = s->header.cluster_size;
573}
574
575/* We have nothing to do for QED reopen, stubs just return
576 * success */
577static int bdrv_qed_reopen_prepare(BDRVReopenState *state,
578 BlockReopenQueue *queue, Error **errp)
579{
580 return 0;
581}
582
583static void bdrv_qed_close(BlockDriverState *bs)
584{
585 BDRVQEDState *s = bs->opaque;
586
587 bdrv_qed_detach_aio_context(bs);
588
589 /* Ensure writes reach stable storage */
590 bdrv_flush(bs->file->bs);
591
592 /* Clean shutdown, no check required on next open */
593 if (s->header.features & QED_F_NEED_CHECK) {
594 s->header.features &= ~QED_F_NEED_CHECK;
595 qed_write_header_sync(s);
596 }
597
598 qed_free_l2_cache(&s->l2_cache);
599 qemu_vfree(s->l1_table);
600}
601
602static int coroutine_fn bdrv_qed_co_create(BlockdevCreateOptions *opts,
603 Error **errp)
604{
605 BlockdevCreateOptionsQed *qed_opts;
606 BlockBackend *blk = NULL;
607 BlockDriverState *bs = NULL;
608
609 QEDHeader header;
610 QEDHeader le_header;
611 uint8_t *l1_table = NULL;
612 size_t l1_size;
613 int ret = 0;
614
615 assert(opts->driver == BLOCKDEV_DRIVER_QED);
616 qed_opts = &opts->u.qed;
617
618 /* Validate options and set default values */
619 if (!qed_opts->has_cluster_size) {
620 qed_opts->cluster_size = QED_DEFAULT_CLUSTER_SIZE;
621 }
622 if (!qed_opts->has_table_size) {
623 qed_opts->table_size = QED_DEFAULT_TABLE_SIZE;
624 }
625
626 if (!qed_is_cluster_size_valid(qed_opts->cluster_size)) {
627 error_setg(errp, "QED cluster size must be within range [%u, %u] "
628 "and power of 2",
629 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE);
630 return -EINVAL;
631 }
632 if (!qed_is_table_size_valid(qed_opts->table_size)) {
633 error_setg(errp, "QED table size must be within range [%u, %u] "
634 "and power of 2",
635 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE);
636 return -EINVAL;
637 }
638 if (!qed_is_image_size_valid(qed_opts->size, qed_opts->cluster_size,
639 qed_opts->table_size))
640 {
641 error_setg(errp, "QED image size must be a non-zero multiple of "
642 "cluster size and less than %" PRIu64 " bytes",
643 qed_max_image_size(qed_opts->cluster_size,
644 qed_opts->table_size));
645 return -EINVAL;
646 }
647
648 /* Create BlockBackend to write to the image */
649 bs = bdrv_open_blockdev_ref(qed_opts->file, errp);
650 if (bs == NULL) {
651 return -EIO;
652 }
653
654 blk = blk_new(bdrv_get_aio_context(bs),
655 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
656 ret = blk_insert_bs(blk, bs, errp);
657 if (ret < 0) {
658 goto out;
659 }
660 blk_set_allow_write_beyond_eof(blk, true);
661
662 /* Prepare image format */
663 header = (QEDHeader) {
664 .magic = QED_MAGIC,
665 .cluster_size = qed_opts->cluster_size,
666 .table_size = qed_opts->table_size,
667 .header_size = 1,
668 .features = 0,
669 .compat_features = 0,
670 .l1_table_offset = qed_opts->cluster_size,
671 .image_size = qed_opts->size,
672 };
673
674 l1_size = header.cluster_size * header.table_size;
675
676 /* File must start empty and grow, check truncate is supported */
677 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp);
678 if (ret < 0) {
679 goto out;
680 }
681
682 if (qed_opts->has_backing_file) {
683 header.features |= QED_F_BACKING_FILE;
684 header.backing_filename_offset = sizeof(le_header);
685 header.backing_filename_size = strlen(qed_opts->backing_file);
686
687 if (qed_opts->has_backing_fmt) {
688 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt);
689 if (qed_fmt_is_raw(backing_fmt)) {
690 header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
691 }
692 }
693 }
694
695 qed_header_cpu_to_le(&header, &le_header);
696 ret = blk_pwrite(blk, 0, &le_header, sizeof(le_header), 0);
697 if (ret < 0) {
698 goto out;
699 }
700 ret = blk_pwrite(blk, sizeof(le_header), qed_opts->backing_file,
701 header.backing_filename_size, 0);
702 if (ret < 0) {
703 goto out;
704 }
705
706 l1_table = g_malloc0(l1_size);
707 ret = blk_pwrite(blk, header.l1_table_offset, l1_table, l1_size, 0);
708 if (ret < 0) {
709 goto out;
710 }
711
712 ret = 0; /* success */
713out:
714 g_free(l1_table);
715 blk_unref(blk);
716 bdrv_unref(bs);
717 return ret;
718}
719
720static int coroutine_fn bdrv_qed_co_create_opts(const char *filename,
721 QemuOpts *opts,
722 Error **errp)
723{
724 BlockdevCreateOptions *create_options = NULL;
725 QDict *qdict;
726 Visitor *v;
727 BlockDriverState *bs = NULL;
728 Error *local_err = NULL;
729 int ret;
730
731 static const QDictRenames opt_renames[] = {
732 { BLOCK_OPT_BACKING_FILE, "backing-file" },
733 { BLOCK_OPT_BACKING_FMT, "backing-fmt" },
734 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
735 { BLOCK_OPT_TABLE_SIZE, "table-size" },
736 { NULL, NULL },
737 };
738
739 /* Parse options and convert legacy syntax */
740 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true);
741
742 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
743 ret = -EINVAL;
744 goto fail;
745 }
746
747 /* Create and open the file (protocol layer) */
748 ret = bdrv_create_file(filename, opts, &local_err);
749 if (ret < 0) {
750 error_propagate(errp, local_err);
751 goto fail;
752 }
753
754 bs = bdrv_open(filename, NULL, NULL,
755 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
756 if (bs == NULL) {
757 ret = -EIO;
758 goto fail;
759 }
760
761 /* Now get the QAPI type BlockdevCreateOptions */
762 qdict_put_str(qdict, "driver", "qed");
763 qdict_put_str(qdict, "file", bs->node_name);
764
765 v = qobject_input_visitor_new_flat_confused(qdict, errp);
766 if (!v) {
767 ret = -EINVAL;
768 goto fail;
769 }
770
771 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
772 visit_free(v);
773
774 if (local_err) {
775 error_propagate(errp, local_err);
776 ret = -EINVAL;
777 goto fail;
778 }
779
780 /* Silently round up size */
781 assert(create_options->driver == BLOCKDEV_DRIVER_QED);
782 create_options->u.qed.size =
783 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE);
784
785 /* Create the qed image (format layer) */
786 ret = bdrv_qed_co_create(create_options, errp);
787
788fail:
789 qobject_unref(qdict);
790 bdrv_unref(bs);
791 qapi_free_BlockdevCreateOptions(create_options);
792 return ret;
793}
794
795static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs,
796 bool want_zero,
797 int64_t pos, int64_t bytes,
798 int64_t *pnum, int64_t *map,
799 BlockDriverState **file)
800{
801 BDRVQEDState *s = bs->opaque;
802 size_t len = MIN(bytes, SIZE_MAX);
803 int status;
804 QEDRequest request = { .l2_table = NULL };
805 uint64_t offset;
806 int ret;
807
808 qemu_co_mutex_lock(&s->table_lock);
809 ret = qed_find_cluster(s, &request, pos, &len, &offset);
810
811 *pnum = len;
812 switch (ret) {
813 case QED_CLUSTER_FOUND:
814 *map = offset | qed_offset_into_cluster(s, pos);
815 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
816 *file = bs->file->bs;
817 break;
818 case QED_CLUSTER_ZERO:
819 status = BDRV_BLOCK_ZERO;
820 break;
821 case QED_CLUSTER_L2:
822 case QED_CLUSTER_L1:
823 status = 0;
824 break;
825 default:
826 assert(ret < 0);
827 status = ret;
828 break;
829 }
830
831 qed_unref_l2_cache_entry(request.l2_table);
832 qemu_co_mutex_unlock(&s->table_lock);
833
834 return status;
835}
836
837static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
838{
839 return acb->bs->opaque;
840}
841
842/**
843 * Read from the backing file or zero-fill if no backing file
844 *
845 * @s: QED state
846 * @pos: Byte position in device
847 * @qiov: Destination I/O vector
848 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
849 * @cb: Completion function
850 * @opaque: User data for completion function
851 *
852 * This function reads qiov->size bytes starting at pos from the backing file.
853 * If there is no backing file then zeroes are read.
854 */
855static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
856 QEMUIOVector *qiov,
857 QEMUIOVector **backing_qiov)
858{
859 uint64_t backing_length = 0;
860 size_t size;
861 int ret;
862
863 /* If there is a backing file, get its length. Treat the absence of a
864 * backing file like a zero length backing file.
865 */
866 if (s->bs->backing) {
867 int64_t l = bdrv_getlength(s->bs->backing->bs);
868 if (l < 0) {
869 return l;
870 }
871 backing_length = l;
872 }
873
874 /* Zero all sectors if reading beyond the end of the backing file */
875 if (pos >= backing_length ||
876 pos + qiov->size > backing_length) {
877 qemu_iovec_memset(qiov, 0, 0, qiov->size);
878 }
879
880 /* Complete now if there are no backing file sectors to read */
881 if (pos >= backing_length) {
882 return 0;
883 }
884
885 /* If the read straddles the end of the backing file, shorten it */
886 size = MIN((uint64_t)backing_length - pos, qiov->size);
887
888 assert(*backing_qiov == NULL);
889 *backing_qiov = g_new(QEMUIOVector, 1);
890 qemu_iovec_init(*backing_qiov, qiov->niov);
891 qemu_iovec_concat(*backing_qiov, qiov, 0, size);
892
893 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO);
894 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0);
895 if (ret < 0) {
896 return ret;
897 }
898 return 0;
899}
900
901/**
902 * Copy data from backing file into the image
903 *
904 * @s: QED state
905 * @pos: Byte position in device
906 * @len: Number of bytes
907 * @offset: Byte offset in image file
908 */
909static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s,
910 uint64_t pos, uint64_t len,
911 uint64_t offset)
912{
913 QEMUIOVector qiov;
914 QEMUIOVector *backing_qiov = NULL;
915 int ret;
916
917 /* Skip copy entirely if there is no work to do */
918 if (len == 0) {
919 return 0;
920 }
921
922 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len);
923
924 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov);
925
926 if (backing_qiov) {
927 qemu_iovec_destroy(backing_qiov);
928 g_free(backing_qiov);
929 backing_qiov = NULL;
930 }
931
932 if (ret) {
933 goto out;
934 }
935
936 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
937 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0);
938 if (ret < 0) {
939 goto out;
940 }
941 ret = 0;
942out:
943 qemu_vfree(qemu_iovec_buf(&qiov));
944 return ret;
945}
946
947/**
948 * Link one or more contiguous clusters into a table
949 *
950 * @s: QED state
951 * @table: L2 table
952 * @index: First cluster index
953 * @n: Number of contiguous clusters
954 * @cluster: First cluster offset
955 *
956 * The cluster offset may be an allocated byte offset in the image file, the
957 * zero cluster marker, or the unallocated cluster marker.
958 *
959 * Called with table_lock held.
960 */
961static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table,
962 int index, unsigned int n,
963 uint64_t cluster)
964{
965 int i;
966 for (i = index; i < index + n; i++) {
967 table->offsets[i] = cluster;
968 if (!qed_offset_is_unalloc_cluster(cluster) &&
969 !qed_offset_is_zero_cluster(cluster)) {
970 cluster += s->header.cluster_size;
971 }
972 }
973}
974
975/* Called with table_lock held. */
976static void coroutine_fn qed_aio_complete(QEDAIOCB *acb)
977{
978 BDRVQEDState *s = acb_to_s(acb);
979
980 /* Free resources */
981 qemu_iovec_destroy(&acb->cur_qiov);
982 qed_unref_l2_cache_entry(acb->request.l2_table);
983
984 /* Free the buffer we may have allocated for zero writes */
985 if (acb->flags & QED_AIOCB_ZERO) {
986 qemu_vfree(acb->qiov->iov[0].iov_base);
987 acb->qiov->iov[0].iov_base = NULL;
988 }
989
990 /* Start next allocating write request waiting behind this one. Note that
991 * requests enqueue themselves when they first hit an unallocated cluster
992 * but they wait until the entire request is finished before waking up the
993 * next request in the queue. This ensures that we don't cycle through
994 * requests multiple times but rather finish one at a time completely.
995 */
996 if (acb == s->allocating_acb) {
997 s->allocating_acb = NULL;
998 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) {
999 qemu_co_queue_next(&s->allocating_write_reqs);
1000 } else if (s->header.features & QED_F_NEED_CHECK) {
1001 qed_start_need_check_timer(s);
1002 }
1003 }
1004}
1005
1006/**
1007 * Update L1 table with new L2 table offset and write it out
1008 *
1009 * Called with table_lock held.
1010 */
1011static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb)
1012{
1013 BDRVQEDState *s = acb_to_s(acb);
1014 CachedL2Table *l2_table = acb->request.l2_table;
1015 uint64_t l2_offset = l2_table->offset;
1016 int index, ret;
1017
1018 index = qed_l1_index(s, acb->cur_pos);
1019 s->l1_table->offsets[index] = l2_table->offset;
1020
1021 ret = qed_write_l1_table(s, index, 1);
1022
1023 /* Commit the current L2 table to the cache */
1024 qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
1025
1026 /* This is guaranteed to succeed because we just committed the entry to the
1027 * cache.
1028 */
1029 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
1030 assert(acb->request.l2_table != NULL);
1031
1032 return ret;
1033}
1034
1035
1036/**
1037 * Update L2 table with new cluster offsets and write them out
1038 *
1039 * Called with table_lock held.
1040 */
1041static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset)
1042{
1043 BDRVQEDState *s = acb_to_s(acb);
1044 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1;
1045 int index, ret;
1046
1047 if (need_alloc) {
1048 qed_unref_l2_cache_entry(acb->request.l2_table);
1049 acb->request.l2_table = qed_new_l2_table(s);
1050 }
1051
1052 index = qed_l2_index(s, acb->cur_pos);
1053 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters,
1054 offset);
1055
1056 if (need_alloc) {
1057 /* Write out the whole new L2 table */
1058 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true);
1059 if (ret) {
1060 return ret;
1061 }
1062 return qed_aio_write_l1_update(acb);
1063 } else {
1064 /* Write out only the updated part of the L2 table */
1065 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters,
1066 false);
1067 if (ret) {
1068 return ret;
1069 }
1070 }
1071 return 0;
1072}
1073
1074/**
1075 * Write data to the image file
1076 *
1077 * Called with table_lock *not* held.
1078 */
1079static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb)
1080{
1081 BDRVQEDState *s = acb_to_s(acb);
1082 uint64_t offset = acb->cur_cluster +
1083 qed_offset_into_cluster(s, acb->cur_pos);
1084
1085 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size);
1086
1087 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);
1088 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size,
1089 &acb->cur_qiov, 0);
1090}
1091
1092/**
1093 * Populate untouched regions of new data cluster
1094 *
1095 * Called with table_lock held.
1096 */
1097static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb)
1098{
1099 BDRVQEDState *s = acb_to_s(acb);
1100 uint64_t start, len, offset;
1101 int ret;
1102
1103 qemu_co_mutex_unlock(&s->table_lock);
1104
1105 /* Populate front untouched region of new data cluster */
1106 start = qed_start_of_cluster(s, acb->cur_pos);
1107 len = qed_offset_into_cluster(s, acb->cur_pos);
1108
1109 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster);
1110 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster);
1111 if (ret < 0) {
1112 goto out;
1113 }
1114
1115 /* Populate back untouched region of new data cluster */
1116 start = acb->cur_pos + acb->cur_qiov.size;
1117 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start;
1118 offset = acb->cur_cluster +
1119 qed_offset_into_cluster(s, acb->cur_pos) +
1120 acb->cur_qiov.size;
1121
1122 trace_qed_aio_write_postfill(s, acb, start, len, offset);
1123 ret = qed_copy_from_backing_file(s, start, len, offset);
1124 if (ret < 0) {
1125 goto out;
1126 }
1127
1128 ret = qed_aio_write_main(acb);
1129 if (ret < 0) {
1130 goto out;
1131 }
1132
1133 if (s->bs->backing) {
1134 /*
1135 * Flush new data clusters before updating the L2 table
1136 *
1137 * This flush is necessary when a backing file is in use. A crash
1138 * during an allocating write could result in empty clusters in the
1139 * image. If the write only touched a subregion of the cluster,
1140 * then backing image sectors have been lost in the untouched
1141 * region. The solution is to flush after writing a new data
1142 * cluster and before updating the L2 table.
1143 */
1144 ret = bdrv_co_flush(s->bs->file->bs);
1145 }
1146
1147out:
1148 qemu_co_mutex_lock(&s->table_lock);
1149 return ret;
1150}
1151
1152/**
1153 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1154 */
1155static bool qed_should_set_need_check(BDRVQEDState *s)
1156{
1157 /* The flush before L2 update path ensures consistency */
1158 if (s->bs->backing) {
1159 return false;
1160 }
1161
1162 return !(s->header.features & QED_F_NEED_CHECK);
1163}
1164
1165/**
1166 * Write new data cluster
1167 *
1168 * @acb: Write request
1169 * @len: Length in bytes
1170 *
1171 * This path is taken when writing to previously unallocated clusters.
1172 *
1173 * Called with table_lock held.
1174 */
1175static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
1176{
1177 BDRVQEDState *s = acb_to_s(acb);
1178 int ret;
1179
1180 /* Cancel timer when the first allocating request comes in */
1181 if (s->allocating_acb == NULL) {
1182 qed_cancel_need_check_timer(s);
1183 }
1184
1185 /* Freeze this request if another allocating write is in progress */
1186 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) {
1187 if (s->allocating_acb != NULL) {
1188 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock);
1189 assert(s->allocating_acb == NULL);
1190 }
1191 s->allocating_acb = acb;
1192 return -EAGAIN; /* start over with looking up table entries */
1193 }
1194
1195 acb->cur_nclusters = qed_bytes_to_clusters(s,
1196 qed_offset_into_cluster(s, acb->cur_pos) + len);
1197 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1198
1199 if (acb->flags & QED_AIOCB_ZERO) {
1200 /* Skip ahead if the clusters are already zero */
1201 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) {
1202 return 0;
1203 }
1204 acb->cur_cluster = 1;
1205 } else {
1206 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);
1207 }
1208
1209 if (qed_should_set_need_check(s)) {
1210 s->header.features |= QED_F_NEED_CHECK;
1211 ret = qed_write_header(s);
1212 if (ret < 0) {
1213 return ret;
1214 }
1215 }
1216
1217 if (!(acb->flags & QED_AIOCB_ZERO)) {
1218 ret = qed_aio_write_cow(acb);
1219 if (ret < 0) {
1220 return ret;
1221 }
1222 }
1223
1224 return qed_aio_write_l2_update(acb, acb->cur_cluster);
1225}
1226
1227/**
1228 * Write data cluster in place
1229 *
1230 * @acb: Write request
1231 * @offset: Cluster offset in bytes
1232 * @len: Length in bytes
1233 *
1234 * This path is taken when writing to already allocated clusters.
1235 *
1236 * Called with table_lock held.
1237 */
1238static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset,
1239 size_t len)
1240{
1241 BDRVQEDState *s = acb_to_s(acb);
1242 int r;
1243
1244 qemu_co_mutex_unlock(&s->table_lock);
1245
1246 /* Allocate buffer for zero writes */
1247 if (acb->flags & QED_AIOCB_ZERO) {
1248 struct iovec *iov = acb->qiov->iov;
1249
1250 if (!iov->iov_base) {
1251 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len);
1252 if (iov->iov_base == NULL) {
1253 r = -ENOMEM;
1254 goto out;
1255 }
1256 memset(iov->iov_base, 0, iov->iov_len);
1257 }
1258 }
1259
1260 /* Calculate the I/O vector */
1261 acb->cur_cluster = offset;
1262 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1263
1264 /* Do the actual write. */
1265 r = qed_aio_write_main(acb);
1266out:
1267 qemu_co_mutex_lock(&s->table_lock);
1268 return r;
1269}
1270
1271/**
1272 * Write data cluster
1273 *
1274 * @opaque: Write request
1275 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1
1276 * @offset: Cluster offset in bytes
1277 * @len: Length in bytes
1278 *
1279 * Called with table_lock held.
1280 */
1281static int coroutine_fn qed_aio_write_data(void *opaque, int ret,
1282 uint64_t offset, size_t len)
1283{
1284 QEDAIOCB *acb = opaque;
1285
1286 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len);
1287
1288 acb->find_cluster_ret = ret;
1289
1290 switch (ret) {
1291 case QED_CLUSTER_FOUND:
1292 return qed_aio_write_inplace(acb, offset, len);
1293
1294 case QED_CLUSTER_L2:
1295 case QED_CLUSTER_L1:
1296 case QED_CLUSTER_ZERO:
1297 return qed_aio_write_alloc(acb, len);
1298
1299 default:
1300 g_assert_not_reached();
1301 }
1302}
1303
1304/**
1305 * Read data cluster
1306 *
1307 * @opaque: Read request
1308 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1
1309 * @offset: Cluster offset in bytes
1310 * @len: Length in bytes
1311 *
1312 * Called with table_lock held.
1313 */
1314static int coroutine_fn qed_aio_read_data(void *opaque, int ret,
1315 uint64_t offset, size_t len)
1316{
1317 QEDAIOCB *acb = opaque;
1318 BDRVQEDState *s = acb_to_s(acb);
1319 BlockDriverState *bs = acb->bs;
1320 int r;
1321
1322 qemu_co_mutex_unlock(&s->table_lock);
1323
1324 /* Adjust offset into cluster */
1325 offset += qed_offset_into_cluster(s, acb->cur_pos);
1326
1327 trace_qed_aio_read_data(s, acb, ret, offset, len);
1328
1329 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1330
1331 /* Handle zero cluster and backing file reads, otherwise read
1332 * data cluster directly.
1333 */
1334 if (ret == QED_CLUSTER_ZERO) {
1335 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size);
1336 r = 0;
1337 } else if (ret != QED_CLUSTER_FOUND) {
1338 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov,
1339 &acb->backing_qiov);
1340 } else {
1341 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
1342 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size,
1343 &acb->cur_qiov, 0);
1344 }
1345
1346 qemu_co_mutex_lock(&s->table_lock);
1347 return r;
1348}
1349
1350/**
1351 * Begin next I/O or complete the request
1352 */
1353static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb)
1354{
1355 BDRVQEDState *s = acb_to_s(acb);
1356 uint64_t offset;
1357 size_t len;
1358 int ret;
1359
1360 qemu_co_mutex_lock(&s->table_lock);
1361 while (1) {
1362 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size);
1363
1364 if (acb->backing_qiov) {
1365 qemu_iovec_destroy(acb->backing_qiov);
1366 g_free(acb->backing_qiov);
1367 acb->backing_qiov = NULL;
1368 }
1369
1370 acb->qiov_offset += acb->cur_qiov.size;
1371 acb->cur_pos += acb->cur_qiov.size;
1372 qemu_iovec_reset(&acb->cur_qiov);
1373
1374 /* Complete request */
1375 if (acb->cur_pos >= acb->end_pos) {
1376 ret = 0;
1377 break;
1378 }
1379
1380 /* Find next cluster and start I/O */
1381 len = acb->end_pos - acb->cur_pos;
1382 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset);
1383 if (ret < 0) {
1384 break;
1385 }
1386
1387 if (acb->flags & QED_AIOCB_WRITE) {
1388 ret = qed_aio_write_data(acb, ret, offset, len);
1389 } else {
1390 ret = qed_aio_read_data(acb, ret, offset, len);
1391 }
1392
1393 if (ret < 0 && ret != -EAGAIN) {
1394 break;
1395 }
1396 }
1397
1398 trace_qed_aio_complete(s, acb, ret);
1399 qed_aio_complete(acb);
1400 qemu_co_mutex_unlock(&s->table_lock);
1401 return ret;
1402}
1403
1404static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num,
1405 QEMUIOVector *qiov, int nb_sectors,
1406 int flags)
1407{
1408 QEDAIOCB acb = {
1409 .bs = bs,
1410 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE,
1411 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE,
1412 .qiov = qiov,
1413 .flags = flags,
1414 };
1415 qemu_iovec_init(&acb.cur_qiov, qiov->niov);
1416
1417 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags);
1418
1419 /* Start request */
1420 return qed_aio_next_io(&acb);
1421}
1422
1423static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs,
1424 int64_t sector_num, int nb_sectors,
1425 QEMUIOVector *qiov)
1426{
1427 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0);
1428}
1429
1430static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs,
1431 int64_t sector_num, int nb_sectors,
1432 QEMUIOVector *qiov, int flags)
1433{
1434 assert(!flags);
1435 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE);
1436}
1437
1438static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
1439 int64_t offset,
1440 int bytes,
1441 BdrvRequestFlags flags)
1442{
1443 BDRVQEDState *s = bs->opaque;
1444
1445 /*
1446 * Zero writes start without an I/O buffer. If a buffer becomes necessary
1447 * then it will be allocated during request processing.
1448 */
1449 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
1450
1451 /* Fall back if the request is not aligned */
1452 if (qed_offset_into_cluster(s, offset) ||
1453 qed_offset_into_cluster(s, bytes)) {
1454 return -ENOTSUP;
1455 }
1456
1457 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov,
1458 bytes >> BDRV_SECTOR_BITS,
1459 QED_AIOCB_WRITE | QED_AIOCB_ZERO);
1460}
1461
1462static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs,
1463 int64_t offset,
1464 PreallocMode prealloc,
1465 Error **errp)
1466{
1467 BDRVQEDState *s = bs->opaque;
1468 uint64_t old_image_size;
1469 int ret;
1470
1471 if (prealloc != PREALLOC_MODE_OFF) {
1472 error_setg(errp, "Unsupported preallocation mode '%s'",
1473 PreallocMode_str(prealloc));
1474 return -ENOTSUP;
1475 }
1476
1477 if (!qed_is_image_size_valid(offset, s->header.cluster_size,
1478 s->header.table_size)) {
1479 error_setg(errp, "Invalid image size specified");
1480 return -EINVAL;
1481 }
1482
1483 if ((uint64_t)offset < s->header.image_size) {
1484 error_setg(errp, "Shrinking images is currently not supported");
1485 return -ENOTSUP;
1486 }
1487
1488 old_image_size = s->header.image_size;
1489 s->header.image_size = offset;
1490 ret = qed_write_header_sync(s);
1491 if (ret < 0) {
1492 s->header.image_size = old_image_size;
1493 error_setg_errno(errp, -ret, "Failed to update the image size");
1494 }
1495 return ret;
1496}
1497
1498static int64_t bdrv_qed_getlength(BlockDriverState *bs)
1499{
1500 BDRVQEDState *s = bs->opaque;
1501 return s->header.image_size;
1502}
1503
1504static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1505{
1506 BDRVQEDState *s = bs->opaque;
1507
1508 memset(bdi, 0, sizeof(*bdi));
1509 bdi->cluster_size = s->header.cluster_size;
1510 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK;
1511 bdi->unallocated_blocks_are_zero = true;
1512 return 0;
1513}
1514
1515static int bdrv_qed_change_backing_file(BlockDriverState *bs,
1516 const char *backing_file,
1517 const char *backing_fmt)
1518{
1519 BDRVQEDState *s = bs->opaque;
1520 QEDHeader new_header, le_header;
1521 void *buffer;
1522 size_t buffer_len, backing_file_len;
1523 int ret;
1524
1525 /* Refuse to set backing filename if unknown compat feature bits are
1526 * active. If the image uses an unknown compat feature then we may not
1527 * know the layout of data following the header structure and cannot safely
1528 * add a new string.
1529 */
1530 if (backing_file && (s->header.compat_features &
1531 ~QED_COMPAT_FEATURE_MASK)) {
1532 return -ENOTSUP;
1533 }
1534
1535 memcpy(&new_header, &s->header, sizeof(new_header));
1536
1537 new_header.features &= ~(QED_F_BACKING_FILE |
1538 QED_F_BACKING_FORMAT_NO_PROBE);
1539
1540 /* Adjust feature flags */
1541 if (backing_file) {
1542 new_header.features |= QED_F_BACKING_FILE;
1543
1544 if (qed_fmt_is_raw(backing_fmt)) {
1545 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
1546 }
1547 }
1548
1549 /* Calculate new header size */
1550 backing_file_len = 0;
1551
1552 if (backing_file) {
1553 backing_file_len = strlen(backing_file);
1554 }
1555
1556 buffer_len = sizeof(new_header);
1557 new_header.backing_filename_offset = buffer_len;
1558 new_header.backing_filename_size = backing_file_len;
1559 buffer_len += backing_file_len;
1560
1561 /* Make sure we can rewrite header without failing */
1562 if (buffer_len > new_header.header_size * new_header.cluster_size) {
1563 return -ENOSPC;
1564 }
1565
1566 /* Prepare new header */
1567 buffer = g_malloc(buffer_len);
1568
1569 qed_header_cpu_to_le(&new_header, &le_header);
1570 memcpy(buffer, &le_header, sizeof(le_header));
1571 buffer_len = sizeof(le_header);
1572
1573 if (backing_file) {
1574 memcpy(buffer + buffer_len, backing_file, backing_file_len);
1575 buffer_len += backing_file_len;
1576 }
1577
1578 /* Write new header */
1579 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
1580 g_free(buffer);
1581 if (ret == 0) {
1582 memcpy(&s->header, &new_header, sizeof(new_header));
1583 }
1584 return ret;
1585}
1586
1587static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs,
1588 Error **errp)
1589{
1590 BDRVQEDState *s = bs->opaque;
1591 Error *local_err = NULL;
1592 int ret;
1593
1594 bdrv_qed_close(bs);
1595
1596 bdrv_qed_init_state(bs);
1597 qemu_co_mutex_lock(&s->table_lock);
1598 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err);
1599 qemu_co_mutex_unlock(&s->table_lock);
1600 if (local_err) {
1601 error_propagate_prepend(errp, local_err,
1602 "Could not reopen qed layer: ");
1603 return;
1604 } else if (ret < 0) {
1605 error_setg_errno(errp, -ret, "Could not reopen qed layer");
1606 return;
1607 }
1608}
1609
1610static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs,
1611 BdrvCheckResult *result,
1612 BdrvCheckMode fix)
1613{
1614 BDRVQEDState *s = bs->opaque;
1615 int ret;
1616
1617 qemu_co_mutex_lock(&s->table_lock);
1618 ret = qed_check(s, result, !!fix);
1619 qemu_co_mutex_unlock(&s->table_lock);
1620
1621 return ret;
1622}
1623
1624static QemuOptsList qed_create_opts = {
1625 .name = "qed-create-opts",
1626 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head),
1627 .desc = {
1628 {
1629 .name = BLOCK_OPT_SIZE,
1630 .type = QEMU_OPT_SIZE,
1631 .help = "Virtual disk size"
1632 },
1633 {
1634 .name = BLOCK_OPT_BACKING_FILE,
1635 .type = QEMU_OPT_STRING,
1636 .help = "File name of a base image"
1637 },
1638 {
1639 .name = BLOCK_OPT_BACKING_FMT,
1640 .type = QEMU_OPT_STRING,
1641 .help = "Image format of the base image"
1642 },
1643 {
1644 .name = BLOCK_OPT_CLUSTER_SIZE,
1645 .type = QEMU_OPT_SIZE,
1646 .help = "Cluster size (in bytes)",
1647 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE)
1648 },
1649 {
1650 .name = BLOCK_OPT_TABLE_SIZE,
1651 .type = QEMU_OPT_SIZE,
1652 .help = "L1/L2 table size (in clusters)"
1653 },
1654 { /* end of list */ }
1655 }
1656};
1657
1658static BlockDriver bdrv_qed = {
1659 .format_name = "qed",
1660 .instance_size = sizeof(BDRVQEDState),
1661 .create_opts = &qed_create_opts,
1662 .supports_backing = true,
1663
1664 .bdrv_probe = bdrv_qed_probe,
1665 .bdrv_open = bdrv_qed_open,
1666 .bdrv_close = bdrv_qed_close,
1667 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
1668 .bdrv_child_perm = bdrv_format_default_perms,
1669 .bdrv_co_create = bdrv_qed_co_create,
1670 .bdrv_co_create_opts = bdrv_qed_co_create_opts,
1671 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1672 .bdrv_has_zero_init_truncate = bdrv_has_zero_init_1,
1673 .bdrv_co_block_status = bdrv_qed_co_block_status,
1674 .bdrv_co_readv = bdrv_qed_co_readv,
1675 .bdrv_co_writev = bdrv_qed_co_writev,
1676 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
1677 .bdrv_co_truncate = bdrv_qed_co_truncate,
1678 .bdrv_getlength = bdrv_qed_getlength,
1679 .bdrv_get_info = bdrv_qed_get_info,
1680 .bdrv_refresh_limits = bdrv_qed_refresh_limits,
1681 .bdrv_change_backing_file = bdrv_qed_change_backing_file,
1682 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache,
1683 .bdrv_co_check = bdrv_qed_co_check,
1684 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
1685 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
1686 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin,
1687};
1688
1689static void bdrv_qed_init(void)
1690{
1691 bdrv_register(&bdrv_qed);
1692}
1693
1694block_init(bdrv_qed_init);
1695