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1.1 root 1: /*
2: * Block driver for the QCOW version 2 format
3: *
4: * Copyright (c) 2004-2006 Fabrice Bellard
5: *
6: * Permission is hereby granted, free of charge, to any person obtaining a copy
7: * of this software and associated documentation files (the "Software"), to deal
8: * in the Software without restriction, including without limitation the rights
9: * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10: * copies of the Software, and to permit persons to whom the Software is
11: * furnished to do so, subject to the following conditions:
12: *
13: * The above copyright notice and this permission notice shall be included in
14: * all copies or substantial portions of the Software.
15: *
16: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17: * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19: * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20: * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21: * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22: * THE SOFTWARE.
23: */
24: #include "qemu-common.h"
25: #include "block_int.h"
26: #include "module.h"
27: #include <zlib.h>
28: #include "aes.h"
29: #include "block/qcow2.h"
30:
31: /*
32: Differences with QCOW:
33:
34: - Support for multiple incremental snapshots.
35: - Memory management by reference counts.
36: - Clusters which have a reference count of one have the bit
37: QCOW_OFLAG_COPIED to optimize write performance.
38: - Size of compressed clusters is stored in sectors to reduce bit usage
39: in the cluster offsets.
40: - Support for storing additional data (such as the VM state) in the
41: snapshots.
42: - If a backing store is used, the cluster size is not constrained
43: (could be backported to QCOW).
44: - L2 tables have always a size of one cluster.
45: */
46:
47:
48: typedef struct {
49: uint32_t magic;
50: uint32_t len;
51: } QCowExtension;
52: #define QCOW_EXT_MAGIC_END 0
53: #define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
54:
55: static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
56: {
57: const QCowHeader *cow_header = (const void *)buf;
58:
59: if (buf_size >= sizeof(QCowHeader) &&
60: be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
61: be32_to_cpu(cow_header->version) == QCOW_VERSION)
62: return 100;
63: else
64: return 0;
65: }
66:
67:
68: /*
69: * read qcow2 extension and fill bs
70: * start reading from start_offset
71: * finish reading upon magic of value 0 or when end_offset reached
72: * unknown magic is skipped (future extension this version knows nothing about)
73: * return 0 upon success, non-0 otherwise
74: */
75: static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
76: uint64_t end_offset)
77: {
78: QCowExtension ext;
79: uint64_t offset;
80:
81: #ifdef DEBUG_EXT
82: printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
83: #endif
84: offset = start_offset;
85: while (offset < end_offset) {
86:
87: #ifdef DEBUG_EXT
88: /* Sanity check */
89: if (offset > s->cluster_size)
90: printf("qcow_handle_extension: suspicious offset %lu\n", offset);
91:
92: printf("attemting to read extended header in offset %lu\n", offset);
93: #endif
94:
1.1.1.6 ! root 95: if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
! 96: fprintf(stderr, "qcow_handle_extension: ERROR: "
! 97: "pread fail from offset %" PRIu64 "\n",
! 98: offset);
1.1 root 99: return 1;
100: }
101: be32_to_cpus(&ext.magic);
102: be32_to_cpus(&ext.len);
103: offset += sizeof(ext);
104: #ifdef DEBUG_EXT
105: printf("ext.magic = 0x%x\n", ext.magic);
106: #endif
107: switch (ext.magic) {
108: case QCOW_EXT_MAGIC_END:
109: return 0;
110:
111: case QCOW_EXT_MAGIC_BACKING_FORMAT:
112: if (ext.len >= sizeof(bs->backing_format)) {
113: fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
114: " (>=%zu)\n",
115: ext.len, sizeof(bs->backing_format));
116: return 2;
117: }
1.1.1.6 ! root 118: if (bdrv_pread(bs->file, offset , bs->backing_format,
1.1 root 119: ext.len) != ext.len)
120: return 3;
121: bs->backing_format[ext.len] = '\0';
122: #ifdef DEBUG_EXT
123: printf("Qcow2: Got format extension %s\n", bs->backing_format);
124: #endif
1.1.1.2 root 125: offset = ((offset + ext.len + 7) & ~7);
1.1 root 126: break;
127:
128: default:
129: /* unknown magic -- just skip it */
1.1.1.2 root 130: offset = ((offset + ext.len + 7) & ~7);
1.1 root 131: break;
132: }
133: }
134:
135: return 0;
136: }
137:
138:
1.1.1.6 ! root 139: static int qcow_open(BlockDriverState *bs, int flags)
1.1 root 140: {
141: BDRVQcowState *s = bs->opaque;
1.1.1.6 ! root 142: int len, i;
1.1 root 143: QCowHeader header;
144: uint64_t ext_end;
145:
1.1.1.6 ! root 146: if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header))
1.1 root 147: goto fail;
148: be32_to_cpus(&header.magic);
149: be32_to_cpus(&header.version);
150: be64_to_cpus(&header.backing_file_offset);
151: be32_to_cpus(&header.backing_file_size);
152: be64_to_cpus(&header.size);
153: be32_to_cpus(&header.cluster_bits);
154: be32_to_cpus(&header.crypt_method);
155: be64_to_cpus(&header.l1_table_offset);
156: be32_to_cpus(&header.l1_size);
157: be64_to_cpus(&header.refcount_table_offset);
158: be32_to_cpus(&header.refcount_table_clusters);
159: be64_to_cpus(&header.snapshots_offset);
160: be32_to_cpus(&header.nb_snapshots);
161:
162: if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
163: goto fail;
1.1.1.2 root 164: if (header.cluster_bits < MIN_CLUSTER_BITS ||
1.1 root 165: header.cluster_bits > MAX_CLUSTER_BITS)
166: goto fail;
167: if (header.crypt_method > QCOW_CRYPT_AES)
168: goto fail;
169: s->crypt_method_header = header.crypt_method;
170: if (s->crypt_method_header)
171: bs->encrypted = 1;
172: s->cluster_bits = header.cluster_bits;
173: s->cluster_size = 1 << s->cluster_bits;
174: s->cluster_sectors = 1 << (s->cluster_bits - 9);
175: s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
176: s->l2_size = 1 << s->l2_bits;
177: bs->total_sectors = header.size / 512;
178: s->csize_shift = (62 - (s->cluster_bits - 8));
179: s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
180: s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
181: s->refcount_table_offset = header.refcount_table_offset;
182: s->refcount_table_size =
183: header.refcount_table_clusters << (s->cluster_bits - 3);
184:
185: s->snapshots_offset = header.snapshots_offset;
186: s->nb_snapshots = header.nb_snapshots;
187:
188: /* read the level 1 table */
189: s->l1_size = header.l1_size;
1.1.1.6 ! root 190: s->l1_vm_state_index = size_to_l1(s, header.size);
1.1 root 191: /* the L1 table must contain at least enough entries to put
192: header.size bytes */
193: if (s->l1_size < s->l1_vm_state_index)
194: goto fail;
195: s->l1_table_offset = header.l1_table_offset;
1.1.1.2 root 196: if (s->l1_size > 0) {
197: s->l1_table = qemu_mallocz(
198: align_offset(s->l1_size * sizeof(uint64_t), 512));
1.1.1.6 ! root 199: if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
1.1.1.2 root 200: s->l1_size * sizeof(uint64_t))
201: goto fail;
202: for(i = 0;i < s->l1_size; i++) {
203: be64_to_cpus(&s->l1_table[i]);
204: }
1.1 root 205: }
206: /* alloc L2 cache */
207: s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
208: s->cluster_cache = qemu_malloc(s->cluster_size);
209: /* one more sector for decompressed data alignment */
210: s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
211: + 512);
212: s->cluster_cache_offset = -1;
213:
214: if (qcow2_refcount_init(bs) < 0)
215: goto fail;
216:
1.1.1.2 root 217: QLIST_INIT(&s->cluster_allocs);
1.1 root 218:
219: /* read qcow2 extensions */
220: if (header.backing_file_offset)
221: ext_end = header.backing_file_offset;
222: else
223: ext_end = s->cluster_size;
224: if (qcow_read_extensions(bs, sizeof(header), ext_end))
225: goto fail;
226:
227: /* read the backing file name */
228: if (header.backing_file_offset != 0) {
229: len = header.backing_file_size;
230: if (len > 1023)
231: len = 1023;
1.1.1.6 ! root 232: if (bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len) != len)
1.1 root 233: goto fail;
234: bs->backing_file[len] = '\0';
235: }
236: if (qcow2_read_snapshots(bs) < 0)
237: goto fail;
238:
239: #ifdef DEBUG_ALLOC
240: qcow2_check_refcounts(bs);
241: #endif
242: return 0;
243:
244: fail:
245: qcow2_free_snapshots(bs);
246: qcow2_refcount_close(bs);
247: qemu_free(s->l1_table);
248: qemu_free(s->l2_cache);
249: qemu_free(s->cluster_cache);
250: qemu_free(s->cluster_data);
251: return -1;
252: }
253:
254: static int qcow_set_key(BlockDriverState *bs, const char *key)
255: {
256: BDRVQcowState *s = bs->opaque;
257: uint8_t keybuf[16];
258: int len, i;
259:
260: memset(keybuf, 0, 16);
261: len = strlen(key);
262: if (len > 16)
263: len = 16;
264: /* XXX: we could compress the chars to 7 bits to increase
265: entropy */
266: for(i = 0;i < len;i++) {
267: keybuf[i] = key[i];
268: }
269: s->crypt_method = s->crypt_method_header;
270:
271: if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
272: return -1;
273: if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
274: return -1;
275: #if 0
276: /* test */
277: {
278: uint8_t in[16];
279: uint8_t out[16];
280: uint8_t tmp[16];
281: for(i=0;i<16;i++)
282: in[i] = i;
283: AES_encrypt(in, tmp, &s->aes_encrypt_key);
284: AES_decrypt(tmp, out, &s->aes_decrypt_key);
285: for(i = 0; i < 16; i++)
286: printf(" %02x", tmp[i]);
287: printf("\n");
288: for(i = 0; i < 16; i++)
289: printf(" %02x", out[i]);
290: printf("\n");
291: }
292: #endif
293: return 0;
294: }
295:
296: static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
297: int nb_sectors, int *pnum)
298: {
299: uint64_t cluster_offset;
1.1.1.6 ! root 300: int ret;
1.1 root 301:
302: *pnum = nb_sectors;
1.1.1.6 ! root 303: /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
! 304: * pass them on today */
! 305: ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
! 306: if (ret < 0) {
! 307: *pnum = 0;
! 308: }
1.1 root 309:
310: return (cluster_offset != 0);
311: }
312:
313: /* handle reading after the end of the backing file */
314: int qcow2_backing_read1(BlockDriverState *bs,
315: int64_t sector_num, uint8_t *buf, int nb_sectors)
316: {
317: int n1;
318: if ((sector_num + nb_sectors) <= bs->total_sectors)
319: return nb_sectors;
320: if (sector_num >= bs->total_sectors)
321: n1 = 0;
322: else
323: n1 = bs->total_sectors - sector_num;
324: memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
325: return n1;
326: }
327:
328: typedef struct QCowAIOCB {
329: BlockDriverAIOCB common;
330: int64_t sector_num;
331: QEMUIOVector *qiov;
332: uint8_t *buf;
333: void *orig_buf;
1.1.1.6 ! root 334: int remaining_sectors;
! 335: int cur_nr_sectors; /* number of sectors in current iteration */
1.1 root 336: uint64_t cluster_offset;
337: uint8_t *cluster_data;
338: BlockDriverAIOCB *hd_aiocb;
339: struct iovec hd_iov;
340: QEMUIOVector hd_qiov;
341: QEMUBH *bh;
342: QCowL2Meta l2meta;
1.1.1.2 root 343: QLIST_ENTRY(QCowAIOCB) next_depend;
1.1 root 344: } QCowAIOCB;
345:
346: static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
347: {
1.1.1.6 ! root 348: QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
1.1 root 349: if (acb->hd_aiocb)
350: bdrv_aio_cancel(acb->hd_aiocb);
351: qemu_aio_release(acb);
352: }
353:
354: static AIOPool qcow_aio_pool = {
355: .aiocb_size = sizeof(QCowAIOCB),
356: .cancel = qcow_aio_cancel,
357: };
358:
359: static void qcow_aio_read_cb(void *opaque, int ret);
360: static void qcow_aio_read_bh(void *opaque)
361: {
362: QCowAIOCB *acb = opaque;
363: qemu_bh_delete(acb->bh);
364: acb->bh = NULL;
365: qcow_aio_read_cb(opaque, 0);
366: }
367:
368: static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
369: {
370: if (acb->bh)
371: return -EIO;
372:
373: acb->bh = qemu_bh_new(cb, acb);
374: if (!acb->bh)
375: return -EIO;
376:
377: qemu_bh_schedule(acb->bh);
378:
379: return 0;
380: }
381:
382: static void qcow_aio_read_cb(void *opaque, int ret)
383: {
384: QCowAIOCB *acb = opaque;
385: BlockDriverState *bs = acb->common.bs;
386: BDRVQcowState *s = bs->opaque;
387: int index_in_cluster, n1;
388:
389: acb->hd_aiocb = NULL;
390: if (ret < 0)
391: goto done;
392:
393: /* post process the read buffer */
394: if (!acb->cluster_offset) {
395: /* nothing to do */
396: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
397: /* nothing to do */
398: } else {
399: if (s->crypt_method) {
400: qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
1.1.1.6 ! root 401: acb->cur_nr_sectors, 0,
1.1 root 402: &s->aes_decrypt_key);
403: }
404: }
405:
1.1.1.6 ! root 406: acb->remaining_sectors -= acb->cur_nr_sectors;
! 407: acb->sector_num += acb->cur_nr_sectors;
! 408: acb->buf += acb->cur_nr_sectors * 512;
1.1 root 409:
1.1.1.6 ! root 410: if (acb->remaining_sectors == 0) {
1.1 root 411: /* request completed */
412: ret = 0;
413: goto done;
414: }
415:
416: /* prepare next AIO request */
1.1.1.6 ! root 417: acb->cur_nr_sectors = acb->remaining_sectors;
! 418: ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
! 419: &acb->cur_nr_sectors, &acb->cluster_offset);
! 420: if (ret < 0) {
! 421: goto done;
! 422: }
! 423:
1.1 root 424: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
425:
426: if (!acb->cluster_offset) {
427: if (bs->backing_hd) {
428: /* read from the base image */
429: n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num,
1.1.1.6 ! root 430: acb->buf, acb->cur_nr_sectors);
1.1 root 431: if (n1 > 0) {
432: acb->hd_iov.iov_base = (void *)acb->buf;
1.1.1.6 ! root 433: acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
1.1 root 434: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.6 ! root 435: BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
1.1 root 436: acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
1.1.1.6 ! root 437: &acb->hd_qiov, acb->cur_nr_sectors,
1.1 root 438: qcow_aio_read_cb, acb);
439: if (acb->hd_aiocb == NULL)
440: goto done;
441: } else {
442: ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
443: if (ret < 0)
444: goto done;
445: }
446: } else {
447: /* Note: in this case, no need to wait */
1.1.1.6 ! root 448: memset(acb->buf, 0, 512 * acb->cur_nr_sectors);
1.1 root 449: ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
450: if (ret < 0)
451: goto done;
452: }
453: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
454: /* add AIO support for compressed blocks ? */
1.1.1.6 ! root 455: if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
1.1 root 456: goto done;
1.1.1.6 ! root 457: memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512,
! 458: 512 * acb->cur_nr_sectors);
1.1 root 459: ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
460: if (ret < 0)
461: goto done;
462: } else {
463: if ((acb->cluster_offset & 511) != 0) {
464: ret = -EIO;
465: goto done;
466: }
467:
468: acb->hd_iov.iov_base = (void *)acb->buf;
1.1.1.6 ! root 469: acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
1.1 root 470: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.6 ! root 471: BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
! 472: acb->hd_aiocb = bdrv_aio_readv(bs->file,
1.1 root 473: (acb->cluster_offset >> 9) + index_in_cluster,
1.1.1.6 ! root 474: &acb->hd_qiov, acb->cur_nr_sectors,
! 475: qcow_aio_read_cb, acb);
1.1.1.4 root 476: if (acb->hd_aiocb == NULL) {
477: ret = -EIO;
1.1 root 478: goto done;
1.1.1.4 root 479: }
1.1 root 480: }
481:
482: return;
483: done:
484: if (acb->qiov->niov > 1) {
485: qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
486: qemu_vfree(acb->orig_buf);
487: }
488: acb->common.cb(acb->common.opaque, ret);
489: qemu_aio_release(acb);
490: }
491:
492: static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
493: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
494: BlockDriverCompletionFunc *cb, void *opaque, int is_write)
495: {
496: QCowAIOCB *acb;
497:
498: acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
499: if (!acb)
500: return NULL;
501: acb->hd_aiocb = NULL;
502: acb->sector_num = sector_num;
503: acb->qiov = qiov;
504: if (qiov->niov > 1) {
505: acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
506: if (is_write)
507: qemu_iovec_to_buffer(qiov, acb->buf);
508: } else {
509: acb->buf = (uint8_t *)qiov->iov->iov_base;
510: }
1.1.1.6 ! root 511: acb->remaining_sectors = nb_sectors;
! 512: acb->cur_nr_sectors = 0;
1.1 root 513: acb->cluster_offset = 0;
514: acb->l2meta.nb_clusters = 0;
1.1.1.2 root 515: QLIST_INIT(&acb->l2meta.dependent_requests);
1.1 root 516: return acb;
517: }
518:
519: static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
520: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
521: BlockDriverCompletionFunc *cb, void *opaque)
522: {
523: QCowAIOCB *acb;
524:
525: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
526: if (!acb)
527: return NULL;
528:
529: qcow_aio_read_cb(acb, 0);
530: return &acb->common;
531: }
532:
533: static void qcow_aio_write_cb(void *opaque, int ret);
534:
535: static void run_dependent_requests(QCowL2Meta *m)
536: {
537: QCowAIOCB *req;
538: QCowAIOCB *next;
539:
540: /* Take the request off the list of running requests */
541: if (m->nb_clusters != 0) {
1.1.1.2 root 542: QLIST_REMOVE(m, next_in_flight);
1.1 root 543: }
544:
1.1.1.6 ! root 545: /* Restart all dependent requests */
! 546: QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) {
1.1 root 547: qcow_aio_write_cb(req, 0);
548: }
549:
550: /* Empty the list for the next part of the request */
1.1.1.2 root 551: QLIST_INIT(&m->dependent_requests);
1.1 root 552: }
553:
554: static void qcow_aio_write_cb(void *opaque, int ret)
555: {
556: QCowAIOCB *acb = opaque;
557: BlockDriverState *bs = acb->common.bs;
558: BDRVQcowState *s = bs->opaque;
559: int index_in_cluster;
560: const uint8_t *src_buf;
561: int n_end;
562:
563: acb->hd_aiocb = NULL;
564:
565: if (ret >= 0) {
1.1.1.3 root 566: ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta);
1.1 root 567: }
568:
569: run_dependent_requests(&acb->l2meta);
570:
571: if (ret < 0)
572: goto done;
573:
1.1.1.6 ! root 574: acb->remaining_sectors -= acb->cur_nr_sectors;
! 575: acb->sector_num += acb->cur_nr_sectors;
! 576: acb->buf += acb->cur_nr_sectors * 512;
1.1 root 577:
1.1.1.6 ! root 578: if (acb->remaining_sectors == 0) {
1.1 root 579: /* request completed */
580: ret = 0;
581: goto done;
582: }
583:
584: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
1.1.1.6 ! root 585: n_end = index_in_cluster + acb->remaining_sectors;
1.1 root 586: if (s->crypt_method &&
587: n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
588: n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
589:
1.1.1.3 root 590: ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
1.1.1.6 ! root 591: index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta);
1.1.1.3 root 592: if (ret < 0) {
593: goto done;
594: }
595:
596: acb->cluster_offset = acb->l2meta.cluster_offset;
1.1 root 597:
598: /* Need to wait for another request? If so, we are done for now. */
1.1.1.3 root 599: if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) {
1.1.1.2 root 600: QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests,
1.1 root 601: acb, next_depend);
602: return;
603: }
604:
1.1.1.3 root 605: assert((acb->cluster_offset & 511) == 0);
606:
1.1 root 607: if (s->crypt_method) {
608: if (!acb->cluster_data) {
609: acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
610: s->cluster_size);
611: }
612: qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
1.1.1.6 ! root 613: acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
1.1 root 614: src_buf = acb->cluster_data;
615: } else {
616: src_buf = acb->buf;
617: }
618: acb->hd_iov.iov_base = (void *)src_buf;
1.1.1.6 ! root 619: acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
1.1 root 620: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.6 ! root 621: BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
! 622: acb->hd_aiocb = bdrv_aio_writev(bs->file,
1.1 root 623: (acb->cluster_offset >> 9) + index_in_cluster,
1.1.1.6 ! root 624: &acb->hd_qiov, acb->cur_nr_sectors,
1.1 root 625: qcow_aio_write_cb, acb);
1.1.1.4 root 626: if (acb->hd_aiocb == NULL) {
627: ret = -EIO;
628: goto fail;
629: }
1.1 root 630:
631: return;
632:
1.1.1.4 root 633: fail:
634: if (acb->l2meta.nb_clusters != 0) {
635: QLIST_REMOVE(&acb->l2meta, next_in_flight);
636: }
1.1 root 637: done:
638: if (acb->qiov->niov > 1)
639: qemu_vfree(acb->orig_buf);
640: acb->common.cb(acb->common.opaque, ret);
641: qemu_aio_release(acb);
642: }
643:
644: static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
645: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
646: BlockDriverCompletionFunc *cb, void *opaque)
647: {
648: BDRVQcowState *s = bs->opaque;
649: QCowAIOCB *acb;
650:
651: s->cluster_cache_offset = -1; /* disable compressed cache */
652:
653: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
654: if (!acb)
655: return NULL;
656:
657: qcow_aio_write_cb(acb, 0);
658: return &acb->common;
659: }
660:
661: static void qcow_close(BlockDriverState *bs)
662: {
663: BDRVQcowState *s = bs->opaque;
664: qemu_free(s->l1_table);
665: qemu_free(s->l2_cache);
666: qemu_free(s->cluster_cache);
667: qemu_free(s->cluster_data);
668: qcow2_refcount_close(bs);
1.1.1.6 ! root 669: }
! 670:
! 671: /*
! 672: * Updates the variable length parts of the qcow2 header, i.e. the backing file
! 673: * name and all extensions. qcow2 was not designed to allow such changes, so if
! 674: * we run out of space (we can only use the first cluster) this function may
! 675: * fail.
! 676: *
! 677: * Returns 0 on success, -errno in error cases.
! 678: */
! 679: static int qcow2_update_ext_header(BlockDriverState *bs,
! 680: const char *backing_file, const char *backing_fmt)
! 681: {
! 682: size_t backing_file_len = 0;
! 683: size_t backing_fmt_len = 0;
! 684: BDRVQcowState *s = bs->opaque;
! 685: QCowExtension ext_backing_fmt = {0, 0};
! 686: int ret;
! 687:
! 688: /* Backing file format doesn't make sense without a backing file */
! 689: if (backing_fmt && !backing_file) {
! 690: return -EINVAL;
! 691: }
! 692:
! 693: /* Prepare the backing file format extension if needed */
! 694: if (backing_fmt) {
! 695: ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
! 696: ext_backing_fmt.magic = cpu_to_be32(QCOW_EXT_MAGIC_BACKING_FORMAT);
! 697: backing_fmt_len = ((sizeof(ext_backing_fmt)
! 698: + strlen(backing_fmt) + 7) & ~7);
! 699: }
! 700:
! 701: /* Check if we can fit the new header into the first cluster */
! 702: if (backing_file) {
! 703: backing_file_len = strlen(backing_file);
! 704: }
! 705:
! 706: size_t header_size = sizeof(QCowHeader) + backing_file_len
! 707: + backing_fmt_len;
! 708:
! 709: if (header_size > s->cluster_size) {
! 710: return -ENOSPC;
! 711: }
! 712:
! 713: /* Rewrite backing file name and qcow2 extensions */
! 714: size_t ext_size = header_size - sizeof(QCowHeader);
! 715: uint8_t buf[ext_size];
! 716: size_t offset = 0;
! 717: size_t backing_file_offset = 0;
! 718:
! 719: if (backing_file) {
! 720: if (backing_fmt) {
! 721: int padding = backing_fmt_len -
! 722: (sizeof(ext_backing_fmt) + strlen(backing_fmt));
! 723:
! 724: memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
! 725: offset += sizeof(ext_backing_fmt);
! 726:
! 727: memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
! 728: offset += strlen(backing_fmt);
! 729:
! 730: memset(buf + offset, 0, padding);
! 731: offset += padding;
! 732: }
! 733:
! 734: memcpy(buf + offset, backing_file, backing_file_len);
! 735: backing_file_offset = sizeof(QCowHeader) + offset;
! 736: }
! 737:
! 738: ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
! 739: if (ret < 0) {
! 740: goto fail;
! 741: }
! 742:
! 743: /* Update header fields */
! 744: uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
! 745: uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
! 746:
! 747: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
! 748: &be_backing_file_offset, sizeof(uint64_t));
! 749: if (ret < 0) {
! 750: goto fail;
! 751: }
! 752:
! 753: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
! 754: &be_backing_file_size, sizeof(uint32_t));
! 755: if (ret < 0) {
! 756: goto fail;
! 757: }
! 758:
! 759: ret = 0;
! 760: fail:
! 761: return ret;
! 762: }
! 763:
! 764: static int qcow2_change_backing_file(BlockDriverState *bs,
! 765: const char *backing_file, const char *backing_fmt)
! 766: {
! 767: return qcow2_update_ext_header(bs, backing_file, backing_fmt);
1.1 root 768: }
769:
770: static int get_bits_from_size(size_t size)
771: {
772: int res = 0;
773:
774: if (size == 0) {
775: return -1;
776: }
777:
778: while (size != 1) {
779: /* Not a power of two */
780: if (size & 1) {
781: return -1;
782: }
783:
784: size >>= 1;
785: res++;
786: }
787:
788: return res;
789: }
790:
1.1.1.2 root 791:
792: static int preallocate(BlockDriverState *bs)
793: {
794: uint64_t nb_sectors;
795: uint64_t offset;
796: int num;
1.1.1.3 root 797: int ret;
1.1.1.2 root 798: QCowL2Meta meta;
799:
800: nb_sectors = bdrv_getlength(bs) >> 9;
801: offset = 0;
802: QLIST_INIT(&meta.dependent_requests);
1.1.1.3 root 803: meta.cluster_offset = 0;
1.1.1.2 root 804:
805: while (nb_sectors) {
806: num = MIN(nb_sectors, INT_MAX >> 9);
1.1.1.3 root 807: ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
808: if (ret < 0) {
1.1.1.6 ! root 809: return ret;
1.1.1.2 root 810: }
811:
1.1.1.6 ! root 812: ret = qcow2_alloc_cluster_link_l2(bs, &meta);
! 813: if (ret < 0) {
1.1.1.3 root 814: qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
1.1.1.6 ! root 815: return ret;
1.1.1.2 root 816: }
817:
818: /* There are no dependent requests, but we need to remove our request
819: * from the list of in-flight requests */
820: run_dependent_requests(&meta);
821:
822: /* TODO Preallocate data if requested */
823:
824: nb_sectors -= num;
825: offset += num << 9;
826: }
827:
828: /*
829: * It is expected that the image file is large enough to actually contain
830: * all of the allocated clusters (otherwise we get failing reads after
831: * EOF). Extend the image to the last allocated sector.
832: */
1.1.1.3 root 833: if (meta.cluster_offset != 0) {
1.1.1.2 root 834: uint8_t buf[512];
835: memset(buf, 0, 512);
1.1.1.6 ! root 836: ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
! 837: if (ret < 0) {
! 838: return ret;
! 839: }
1.1.1.2 root 840: }
841:
842: return 0;
843: }
844:
1.1 root 845: static int qcow_create2(const char *filename, int64_t total_size,
846: const char *backing_file, const char *backing_format,
1.1.1.2 root 847: int flags, size_t cluster_size, int prealloc)
1.1 root 848: {
849:
850: int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
1.1.1.5 root 851: int ref_clusters, reftable_clusters, backing_format_len = 0;
1.1.1.2 root 852: int rounded_ext_bf_len = 0;
1.1 root 853: QCowHeader header;
854: uint64_t tmp, offset;
1.1.1.5 root 855: uint64_t old_ref_clusters;
1.1 root 856: QCowCreateState s1, *s = &s1;
857: QCowExtension ext_bf = {0, 0};
1.1.1.6 ! root 858: int ret;
1.1 root 859:
860: memset(s, 0, sizeof(*s));
861:
862: fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
863: if (fd < 0)
1.1.1.6 ! root 864: return -errno;
1.1 root 865: memset(&header, 0, sizeof(header));
866: header.magic = cpu_to_be32(QCOW_MAGIC);
867: header.version = cpu_to_be32(QCOW_VERSION);
868: header.size = cpu_to_be64(total_size * 512);
869: header_size = sizeof(header);
870: backing_filename_len = 0;
871: if (backing_file) {
872: if (backing_format) {
873: ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT;
874: backing_format_len = strlen(backing_format);
1.1.1.2 root 875: ext_bf.len = backing_format_len;
876: rounded_ext_bf_len = (sizeof(ext_bf) + ext_bf.len + 7) & ~7;
877: header_size += rounded_ext_bf_len;
1.1 root 878: }
879: header.backing_file_offset = cpu_to_be64(header_size);
880: backing_filename_len = strlen(backing_file);
881: header.backing_file_size = cpu_to_be32(backing_filename_len);
882: header_size += backing_filename_len;
883: }
884:
885: /* Cluster size */
886: s->cluster_bits = get_bits_from_size(cluster_size);
887: if (s->cluster_bits < MIN_CLUSTER_BITS ||
888: s->cluster_bits > MAX_CLUSTER_BITS)
889: {
890: fprintf(stderr, "Cluster size must be a power of two between "
891: "%d and %dk\n",
892: 1 << MIN_CLUSTER_BITS,
893: 1 << (MAX_CLUSTER_BITS - 10));
894: return -EINVAL;
895: }
896: s->cluster_size = 1 << s->cluster_bits;
897:
898: header.cluster_bits = cpu_to_be32(s->cluster_bits);
899: header_size = (header_size + 7) & ~7;
900: if (flags & BLOCK_FLAG_ENCRYPT) {
901: header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
902: } else {
903: header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
904: }
905: l2_bits = s->cluster_bits - 3;
906: shift = s->cluster_bits + l2_bits;
907: l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
908: offset = align_offset(header_size, s->cluster_size);
909: s->l1_table_offset = offset;
910: header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
911: header.l1_size = cpu_to_be32(l1_size);
912: offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
913:
1.1.1.5 root 914: /* count how many refcount blocks needed */
915:
916: #define NUM_CLUSTERS(bytes) \
917: (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
918:
919: ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
920:
921: do {
922: uint64_t image_clusters;
923: old_ref_clusters = ref_clusters;
924:
925: /* Number of clusters used for the refcount table */
926: reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
927:
928: /* Number of clusters that the whole image will have */
929: image_clusters = NUM_CLUSTERS(offset) + ref_clusters
930: + reftable_clusters;
931:
932: /* Number of refcount blocks needed for the image */
933: ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
934:
935: } while (ref_clusters != old_ref_clusters);
936:
937: s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size);
1.1 root 938:
939: s->refcount_table_offset = offset;
940: header.refcount_table_offset = cpu_to_be64(offset);
1.1.1.5 root 941: header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
942: offset += (reftable_clusters * s->cluster_size);
1.1 root 943: s->refcount_block_offset = offset;
944:
945: for (i=0; i < ref_clusters; i++) {
946: s->refcount_table[i] = cpu_to_be64(offset);
947: offset += s->cluster_size;
948: }
949:
950: s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size);
951:
952: /* update refcounts */
953: qcow2_create_refcount_update(s, 0, header_size);
954: qcow2_create_refcount_update(s, s->l1_table_offset,
955: l1_size * sizeof(uint64_t));
1.1.1.5 root 956: qcow2_create_refcount_update(s, s->refcount_table_offset,
957: reftable_clusters * s->cluster_size);
1.1 root 958: qcow2_create_refcount_update(s, s->refcount_block_offset,
959: ref_clusters * s->cluster_size);
960:
961: /* write all the data */
1.1.1.6 ! root 962: ret = qemu_write_full(fd, &header, sizeof(header));
! 963: if (ret != sizeof(header)) {
! 964: ret = -errno;
! 965: goto exit;
! 966: }
1.1 root 967: if (backing_file) {
968: if (backing_format_len) {
969: char zero[16];
1.1.1.2 root 970: int padding = rounded_ext_bf_len - (ext_bf.len + sizeof(ext_bf));
1.1 root 971:
972: memset(zero, 0, sizeof(zero));
973: cpu_to_be32s(&ext_bf.magic);
974: cpu_to_be32s(&ext_bf.len);
1.1.1.6 ! root 975: ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
! 976: if (ret != sizeof(ext_bf)) {
! 977: ret = -errno;
! 978: goto exit;
! 979: }
! 980: ret = qemu_write_full(fd, backing_format, backing_format_len);
! 981: if (ret != backing_format_len) {
! 982: ret = -errno;
! 983: goto exit;
! 984: }
1.1.1.2 root 985: if (padding > 0) {
1.1.1.6 ! root 986: ret = qemu_write_full(fd, zero, padding);
! 987: if (ret != padding) {
! 988: ret = -errno;
! 989: goto exit;
! 990: }
1.1 root 991: }
992: }
1.1.1.6 ! root 993: ret = qemu_write_full(fd, backing_file, backing_filename_len);
! 994: if (ret != backing_filename_len) {
! 995: ret = -errno;
! 996: goto exit;
! 997: }
1.1 root 998: }
999: lseek(fd, s->l1_table_offset, SEEK_SET);
1000: tmp = 0;
1001: for(i = 0;i < l1_size; i++) {
1.1.1.6 ! root 1002: ret = qemu_write_full(fd, &tmp, sizeof(tmp));
! 1003: if (ret != sizeof(tmp)) {
! 1004: ret = -errno;
! 1005: goto exit;
! 1006: }
1.1 root 1007: }
1008: lseek(fd, s->refcount_table_offset, SEEK_SET);
1.1.1.6 ! root 1009: ret = qemu_write_full(fd, s->refcount_table,
1.1.1.5 root 1010: reftable_clusters * s->cluster_size);
1.1.1.6 ! root 1011: if (ret != reftable_clusters * s->cluster_size) {
! 1012: ret = -errno;
! 1013: goto exit;
! 1014: }
1.1 root 1015:
1016: lseek(fd, s->refcount_block_offset, SEEK_SET);
1.1.1.6 ! root 1017: ret = qemu_write_full(fd, s->refcount_block,
! 1018: ref_clusters * s->cluster_size);
! 1019: if (ret != ref_clusters * s->cluster_size) {
! 1020: ret = -errno;
! 1021: goto exit;
! 1022: }
1.1 root 1023:
1.1.1.6 ! root 1024: ret = 0;
! 1025: exit:
1.1 root 1026: qemu_free(s->refcount_table);
1027: qemu_free(s->refcount_block);
1028: close(fd);
1.1.1.2 root 1029:
1030: /* Preallocate metadata */
1.1.1.6 ! root 1031: if (ret == 0 && prealloc) {
1.1.1.2 root 1032: BlockDriverState *bs;
1.1.1.6 ! root 1033: BlockDriver *drv = bdrv_find_format("qcow2");
1.1.1.2 root 1034: bs = bdrv_new("");
1.1.1.6 ! root 1035: bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv);
! 1036: ret = preallocate(bs);
1.1.1.2 root 1037: bdrv_close(bs);
1038: }
1039:
1.1.1.6 ! root 1040: return ret;
1.1 root 1041: }
1042:
1043: static int qcow_create(const char *filename, QEMUOptionParameter *options)
1044: {
1045: const char *backing_file = NULL;
1046: const char *backing_fmt = NULL;
1047: uint64_t sectors = 0;
1048: int flags = 0;
1049: size_t cluster_size = 65536;
1.1.1.2 root 1050: int prealloc = 0;
1.1 root 1051:
1052: /* Read out options */
1053: while (options && options->name) {
1054: if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
1055: sectors = options->value.n / 512;
1056: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
1057: backing_file = options->value.s;
1058: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
1059: backing_fmt = options->value.s;
1060: } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
1061: flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
1062: } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
1063: if (options->value.n) {
1064: cluster_size = options->value.n;
1065: }
1.1.1.2 root 1066: } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
1067: if (!options->value.s || !strcmp(options->value.s, "off")) {
1068: prealloc = 0;
1069: } else if (!strcmp(options->value.s, "metadata")) {
1070: prealloc = 1;
1071: } else {
1072: fprintf(stderr, "Invalid preallocation mode: '%s'\n",
1073: options->value.s);
1074: return -EINVAL;
1075: }
1.1 root 1076: }
1077: options++;
1078: }
1079:
1.1.1.2 root 1080: if (backing_file && prealloc) {
1081: fprintf(stderr, "Backing file and preallocation cannot be used at "
1082: "the same time\n");
1083: return -EINVAL;
1084: }
1085:
1.1 root 1086: return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
1.1.1.2 root 1087: cluster_size, prealloc);
1.1 root 1088: }
1089:
1090: static int qcow_make_empty(BlockDriverState *bs)
1091: {
1092: #if 0
1093: /* XXX: not correct */
1094: BDRVQcowState *s = bs->opaque;
1095: uint32_t l1_length = s->l1_size * sizeof(uint64_t);
1096: int ret;
1097:
1098: memset(s->l1_table, 0, l1_length);
1.1.1.6 ! root 1099: if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
1.1 root 1100: return -1;
1.1.1.6 ! root 1101: ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
1.1 root 1102: if (ret < 0)
1103: return ret;
1104:
1105: l2_cache_reset(bs);
1106: #endif
1107: return 0;
1108: }
1109:
1.1.1.6 ! root 1110: static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
! 1111: {
! 1112: BDRVQcowState *s = bs->opaque;
! 1113: int ret, new_l1_size;
! 1114:
! 1115: if (offset & 511) {
! 1116: return -EINVAL;
! 1117: }
! 1118:
! 1119: /* cannot proceed if image has snapshots */
! 1120: if (s->nb_snapshots) {
! 1121: return -ENOTSUP;
! 1122: }
! 1123:
! 1124: /* shrinking is currently not supported */
! 1125: if (offset < bs->total_sectors * 512) {
! 1126: return -ENOTSUP;
! 1127: }
! 1128:
! 1129: new_l1_size = size_to_l1(s, offset);
! 1130: ret = qcow2_grow_l1_table(bs, new_l1_size);
! 1131: if (ret < 0) {
! 1132: return ret;
! 1133: }
! 1134:
! 1135: /* write updated header.size */
! 1136: offset = cpu_to_be64(offset);
! 1137: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
! 1138: &offset, sizeof(uint64_t));
! 1139: if (ret < 0) {
! 1140: return ret;
! 1141: }
! 1142:
! 1143: s->l1_vm_state_index = new_l1_size;
! 1144: return 0;
! 1145: }
! 1146:
1.1 root 1147: /* XXX: put compressed sectors first, then all the cluster aligned
1148: tables to avoid losing bytes in alignment */
1149: static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
1150: const uint8_t *buf, int nb_sectors)
1151: {
1152: BDRVQcowState *s = bs->opaque;
1153: z_stream strm;
1154: int ret, out_len;
1155: uint8_t *out_buf;
1156: uint64_t cluster_offset;
1157:
1158: if (nb_sectors == 0) {
1159: /* align end of file to a sector boundary to ease reading with
1160: sector based I/Os */
1.1.1.6 ! root 1161: cluster_offset = bdrv_getlength(bs->file);
1.1 root 1162: cluster_offset = (cluster_offset + 511) & ~511;
1.1.1.6 ! root 1163: bdrv_truncate(bs->file, cluster_offset);
1.1 root 1164: return 0;
1165: }
1166:
1167: if (nb_sectors != s->cluster_sectors)
1168: return -EINVAL;
1169:
1170: out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
1171:
1172: /* best compression, small window, no zlib header */
1173: memset(&strm, 0, sizeof(strm));
1174: ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
1175: Z_DEFLATED, -12,
1176: 9, Z_DEFAULT_STRATEGY);
1177: if (ret != 0) {
1178: qemu_free(out_buf);
1179: return -1;
1180: }
1181:
1182: strm.avail_in = s->cluster_size;
1183: strm.next_in = (uint8_t *)buf;
1184: strm.avail_out = s->cluster_size;
1185: strm.next_out = out_buf;
1186:
1187: ret = deflate(&strm, Z_FINISH);
1188: if (ret != Z_STREAM_END && ret != Z_OK) {
1189: qemu_free(out_buf);
1190: deflateEnd(&strm);
1191: return -1;
1192: }
1193: out_len = strm.next_out - out_buf;
1194:
1195: deflateEnd(&strm);
1196:
1197: if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
1198: /* could not compress: write normal cluster */
1199: bdrv_write(bs, sector_num, buf, s->cluster_sectors);
1200: } else {
1201: cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
1202: sector_num << 9, out_len);
1203: if (!cluster_offset)
1204: return -1;
1205: cluster_offset &= s->cluster_offset_mask;
1.1.1.6 ! root 1206: BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
! 1207: if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
1.1 root 1208: qemu_free(out_buf);
1209: return -1;
1210: }
1211: }
1212:
1213: qemu_free(out_buf);
1214: return 0;
1215: }
1216:
1217: static void qcow_flush(BlockDriverState *bs)
1218: {
1.1.1.6 ! root 1219: bdrv_flush(bs->file);
! 1220: }
! 1221:
! 1222: static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
! 1223: BlockDriverCompletionFunc *cb, void *opaque)
! 1224: {
! 1225: return bdrv_aio_flush(bs->file, cb, opaque);
1.1 root 1226: }
1227:
1228: static int64_t qcow_vm_state_offset(BDRVQcowState *s)
1229: {
1230: return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
1231: }
1232:
1233: static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1234: {
1235: BDRVQcowState *s = bs->opaque;
1236: bdi->cluster_size = s->cluster_size;
1237: bdi->vm_state_offset = qcow_vm_state_offset(s);
1238: return 0;
1239: }
1240:
1241:
1.1.1.6 ! root 1242: static int qcow_check(BlockDriverState *bs, BdrvCheckResult *result)
1.1 root 1243: {
1.1.1.6 ! root 1244: return qcow2_check_refcounts(bs, result);
1.1 root 1245: }
1246:
1247: #if 0
1248: static void dump_refcounts(BlockDriverState *bs)
1249: {
1250: BDRVQcowState *s = bs->opaque;
1251: int64_t nb_clusters, k, k1, size;
1252: int refcount;
1253:
1.1.1.6 ! root 1254: size = bdrv_getlength(bs->file);
1.1 root 1255: nb_clusters = size_to_clusters(s, size);
1256: for(k = 0; k < nb_clusters;) {
1257: k1 = k;
1258: refcount = get_refcount(bs, k);
1259: k++;
1260: while (k < nb_clusters && get_refcount(bs, k) == refcount)
1261: k++;
1.1.1.6 ! root 1262: printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
! 1263: k - k1);
1.1 root 1264: }
1265: }
1266: #endif
1267:
1268: static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1269: int64_t pos, int size)
1270: {
1271: BDRVQcowState *s = bs->opaque;
1272: int growable = bs->growable;
1.1.1.3 root 1273: int ret;
1.1 root 1274:
1.1.1.6 ! root 1275: BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
1.1 root 1276: bs->growable = 1;
1.1.1.3 root 1277: ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
1.1 root 1278: bs->growable = growable;
1279:
1.1.1.3 root 1280: return ret;
1.1 root 1281: }
1282:
1283: static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1284: int64_t pos, int size)
1285: {
1286: BDRVQcowState *s = bs->opaque;
1287: int growable = bs->growable;
1288: int ret;
1289:
1.1.1.6 ! root 1290: BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
1.1 root 1291: bs->growable = 1;
1292: ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
1293: bs->growable = growable;
1294:
1295: return ret;
1296: }
1297:
1298: static QEMUOptionParameter qcow_create_options[] = {
1299: {
1300: .name = BLOCK_OPT_SIZE,
1301: .type = OPT_SIZE,
1302: .help = "Virtual disk size"
1303: },
1304: {
1305: .name = BLOCK_OPT_BACKING_FILE,
1306: .type = OPT_STRING,
1307: .help = "File name of a base image"
1308: },
1309: {
1310: .name = BLOCK_OPT_BACKING_FMT,
1311: .type = OPT_STRING,
1312: .help = "Image format of the base image"
1313: },
1314: {
1315: .name = BLOCK_OPT_ENCRYPT,
1316: .type = OPT_FLAG,
1317: .help = "Encrypt the image"
1318: },
1319: {
1320: .name = BLOCK_OPT_CLUSTER_SIZE,
1321: .type = OPT_SIZE,
1322: .help = "qcow2 cluster size"
1323: },
1.1.1.2 root 1324: {
1325: .name = BLOCK_OPT_PREALLOC,
1326: .type = OPT_STRING,
1327: .help = "Preallocation mode (allowed values: off, metadata)"
1328: },
1.1 root 1329: { NULL }
1330: };
1331:
1332: static BlockDriver bdrv_qcow2 = {
1333: .format_name = "qcow2",
1334: .instance_size = sizeof(BDRVQcowState),
1335: .bdrv_probe = qcow_probe,
1336: .bdrv_open = qcow_open,
1337: .bdrv_close = qcow_close,
1338: .bdrv_create = qcow_create,
1339: .bdrv_flush = qcow_flush,
1340: .bdrv_is_allocated = qcow_is_allocated,
1341: .bdrv_set_key = qcow_set_key,
1342: .bdrv_make_empty = qcow_make_empty,
1343:
1344: .bdrv_aio_readv = qcow_aio_readv,
1345: .bdrv_aio_writev = qcow_aio_writev,
1.1.1.6 ! root 1346: .bdrv_aio_flush = qcow_aio_flush,
! 1347:
! 1348: .bdrv_truncate = qcow2_truncate,
! 1349: .bdrv_write_compressed = qcow_write_compressed,
1.1 root 1350:
1351: .bdrv_snapshot_create = qcow2_snapshot_create,
1352: .bdrv_snapshot_goto = qcow2_snapshot_goto,
1353: .bdrv_snapshot_delete = qcow2_snapshot_delete,
1354: .bdrv_snapshot_list = qcow2_snapshot_list,
1355: .bdrv_get_info = qcow_get_info,
1356:
1357: .bdrv_save_vmstate = qcow_save_vmstate,
1358: .bdrv_load_vmstate = qcow_load_vmstate,
1359:
1.1.1.6 ! root 1360: .bdrv_change_backing_file = qcow2_change_backing_file,
! 1361:
1.1 root 1362: .create_options = qcow_create_options,
1363: .bdrv_check = qcow_check,
1364: };
1365:
1366: static void bdrv_qcow2_init(void)
1367: {
1368: bdrv_register(&bdrv_qcow2);
1369: }
1370:
1371: block_init(bdrv_qcow2_init);
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