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1.1 root 1: /*
2: * Block driver for the QCOW 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:
30: /**************************************************************/
31: /* QEMU COW block driver with compression and encryption support */
32:
33: #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
34: #define QCOW_VERSION 1
35:
36: #define QCOW_CRYPT_NONE 0
37: #define QCOW_CRYPT_AES 1
38:
39: #define QCOW_OFLAG_COMPRESSED (1LL << 63)
40:
41: typedef struct QCowHeader {
42: uint32_t magic;
43: uint32_t version;
44: uint64_t backing_file_offset;
45: uint32_t backing_file_size;
46: uint32_t mtime;
47: uint64_t size; /* in bytes */
48: uint8_t cluster_bits;
49: uint8_t l2_bits;
50: uint32_t crypt_method;
51: uint64_t l1_table_offset;
52: } QCowHeader;
53:
54: #define L2_CACHE_SIZE 16
55:
56: typedef struct BDRVQcowState {
57: int cluster_bits;
58: int cluster_size;
59: int cluster_sectors;
60: int l2_bits;
61: int l2_size;
62: int l1_size;
63: uint64_t cluster_offset_mask;
64: uint64_t l1_table_offset;
65: uint64_t *l1_table;
66: uint64_t *l2_cache;
67: uint64_t l2_cache_offsets[L2_CACHE_SIZE];
68: uint32_t l2_cache_counts[L2_CACHE_SIZE];
69: uint8_t *cluster_cache;
70: uint8_t *cluster_data;
71: uint64_t cluster_cache_offset;
72: uint32_t crypt_method; /* current crypt method, 0 if no key yet */
73: uint32_t crypt_method_header;
74: AES_KEY aes_encrypt_key;
75: AES_KEY aes_decrypt_key;
76: } BDRVQcowState;
77:
1.1.1.3 root 78: static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
1.1 root 79:
80: static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
81: {
82: const QCowHeader *cow_header = (const void *)buf;
83:
84: if (buf_size >= sizeof(QCowHeader) &&
85: be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
86: be32_to_cpu(cow_header->version) == QCOW_VERSION)
87: return 100;
88: else
89: return 0;
90: }
91:
1.1.1.3 root 92: static int qcow_open(BlockDriverState *bs, int flags)
1.1 root 93: {
94: BDRVQcowState *s = bs->opaque;
1.1.1.3 root 95: int len, i, shift;
1.1 root 96: QCowHeader header;
97:
1.1.1.3 root 98: if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header))
1.1 root 99: goto fail;
100: be32_to_cpus(&header.magic);
101: be32_to_cpus(&header.version);
102: be64_to_cpus(&header.backing_file_offset);
103: be32_to_cpus(&header.backing_file_size);
104: be32_to_cpus(&header.mtime);
105: be64_to_cpus(&header.size);
106: be32_to_cpus(&header.crypt_method);
107: be64_to_cpus(&header.l1_table_offset);
108:
109: if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
110: goto fail;
111: if (header.size <= 1 || header.cluster_bits < 9)
112: goto fail;
113: if (header.crypt_method > QCOW_CRYPT_AES)
114: goto fail;
115: s->crypt_method_header = header.crypt_method;
116: if (s->crypt_method_header)
117: bs->encrypted = 1;
118: s->cluster_bits = header.cluster_bits;
119: s->cluster_size = 1 << s->cluster_bits;
120: s->cluster_sectors = 1 << (s->cluster_bits - 9);
121: s->l2_bits = header.l2_bits;
122: s->l2_size = 1 << s->l2_bits;
123: bs->total_sectors = header.size / 512;
124: s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
125:
126: /* read the level 1 table */
127: shift = s->cluster_bits + s->l2_bits;
128: s->l1_size = (header.size + (1LL << shift) - 1) >> shift;
129:
130: s->l1_table_offset = header.l1_table_offset;
131: s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
132: if (!s->l1_table)
133: goto fail;
1.1.1.3 root 134: if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
1.1 root 135: s->l1_size * sizeof(uint64_t))
136: goto fail;
137: for(i = 0;i < s->l1_size; i++) {
138: be64_to_cpus(&s->l1_table[i]);
139: }
140: /* alloc L2 cache */
141: s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
142: if (!s->l2_cache)
143: goto fail;
144: s->cluster_cache = qemu_malloc(s->cluster_size);
145: if (!s->cluster_cache)
146: goto fail;
147: s->cluster_data = qemu_malloc(s->cluster_size);
148: if (!s->cluster_data)
149: goto fail;
150: s->cluster_cache_offset = -1;
151:
152: /* read the backing file name */
153: if (header.backing_file_offset != 0) {
154: len = header.backing_file_size;
155: if (len > 1023)
156: len = 1023;
1.1.1.3 root 157: if (bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len) != len)
1.1 root 158: goto fail;
159: bs->backing_file[len] = '\0';
160: }
161: return 0;
162:
163: fail:
164: qemu_free(s->l1_table);
165: qemu_free(s->l2_cache);
166: qemu_free(s->cluster_cache);
167: qemu_free(s->cluster_data);
168: return -1;
169: }
170:
171: static int qcow_set_key(BlockDriverState *bs, const char *key)
172: {
173: BDRVQcowState *s = bs->opaque;
174: uint8_t keybuf[16];
175: int len, i;
176:
177: memset(keybuf, 0, 16);
178: len = strlen(key);
179: if (len > 16)
180: len = 16;
181: /* XXX: we could compress the chars to 7 bits to increase
182: entropy */
183: for(i = 0;i < len;i++) {
184: keybuf[i] = key[i];
185: }
186: s->crypt_method = s->crypt_method_header;
187:
188: if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
189: return -1;
190: if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
191: return -1;
192: #if 0
193: /* test */
194: {
195: uint8_t in[16];
196: uint8_t out[16];
197: uint8_t tmp[16];
198: for(i=0;i<16;i++)
199: in[i] = i;
200: AES_encrypt(in, tmp, &s->aes_encrypt_key);
201: AES_decrypt(tmp, out, &s->aes_decrypt_key);
202: for(i = 0; i < 16; i++)
203: printf(" %02x", tmp[i]);
204: printf("\n");
205: for(i = 0; i < 16; i++)
206: printf(" %02x", out[i]);
207: printf("\n");
208: }
209: #endif
210: return 0;
211: }
212:
213: /* The crypt function is compatible with the linux cryptoloop
214: algorithm for < 4 GB images. NOTE: out_buf == in_buf is
215: supported */
216: static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
217: uint8_t *out_buf, const uint8_t *in_buf,
218: int nb_sectors, int enc,
219: const AES_KEY *key)
220: {
221: union {
222: uint64_t ll[2];
223: uint8_t b[16];
224: } ivec;
225: int i;
226:
227: for(i = 0; i < nb_sectors; i++) {
228: ivec.ll[0] = cpu_to_le64(sector_num);
229: ivec.ll[1] = 0;
230: AES_cbc_encrypt(in_buf, out_buf, 512, key,
231: ivec.b, enc);
232: sector_num++;
233: in_buf += 512;
234: out_buf += 512;
235: }
236: }
237:
238: /* 'allocate' is:
239: *
240: * 0 to not allocate.
241: *
242: * 1 to allocate a normal cluster (for sector indexes 'n_start' to
243: * 'n_end')
244: *
245: * 2 to allocate a compressed cluster of size
246: * 'compressed_size'. 'compressed_size' must be > 0 and <
247: * cluster_size
248: *
249: * return 0 if not allocated.
250: */
251: static uint64_t get_cluster_offset(BlockDriverState *bs,
252: uint64_t offset, int allocate,
253: int compressed_size,
254: int n_start, int n_end)
255: {
256: BDRVQcowState *s = bs->opaque;
257: int min_index, i, j, l1_index, l2_index;
258: uint64_t l2_offset, *l2_table, cluster_offset, tmp;
259: uint32_t min_count;
260: int new_l2_table;
261:
262: l1_index = offset >> (s->l2_bits + s->cluster_bits);
263: l2_offset = s->l1_table[l1_index];
264: new_l2_table = 0;
265: if (!l2_offset) {
266: if (!allocate)
267: return 0;
268: /* allocate a new l2 entry */
1.1.1.3 root 269: l2_offset = bdrv_getlength(bs->file);
1.1 root 270: /* round to cluster size */
271: l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1);
272: /* update the L1 entry */
273: s->l1_table[l1_index] = l2_offset;
274: tmp = cpu_to_be64(l2_offset);
1.1.1.3 root 275: if (bdrv_pwrite_sync(bs->file,
1.1.1.2 root 276: s->l1_table_offset + l1_index * sizeof(tmp),
277: &tmp, sizeof(tmp)) < 0)
1.1 root 278: return 0;
279: new_l2_table = 1;
280: }
281: for(i = 0; i < L2_CACHE_SIZE; i++) {
282: if (l2_offset == s->l2_cache_offsets[i]) {
283: /* increment the hit count */
284: if (++s->l2_cache_counts[i] == 0xffffffff) {
285: for(j = 0; j < L2_CACHE_SIZE; j++) {
286: s->l2_cache_counts[j] >>= 1;
287: }
288: }
289: l2_table = s->l2_cache + (i << s->l2_bits);
290: goto found;
291: }
292: }
293: /* not found: load a new entry in the least used one */
294: min_index = 0;
295: min_count = 0xffffffff;
296: for(i = 0; i < L2_CACHE_SIZE; i++) {
297: if (s->l2_cache_counts[i] < min_count) {
298: min_count = s->l2_cache_counts[i];
299: min_index = i;
300: }
301: }
302: l2_table = s->l2_cache + (min_index << s->l2_bits);
303: if (new_l2_table) {
304: memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
1.1.1.3 root 305: if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
1.1.1.2 root 306: s->l2_size * sizeof(uint64_t)) < 0)
1.1 root 307: return 0;
308: } else {
1.1.1.3 root 309: if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
1.1 root 310: s->l2_size * sizeof(uint64_t))
311: return 0;
312: }
313: s->l2_cache_offsets[min_index] = l2_offset;
314: s->l2_cache_counts[min_index] = 1;
315: found:
316: l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
317: cluster_offset = be64_to_cpu(l2_table[l2_index]);
318: if (!cluster_offset ||
319: ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
320: if (!allocate)
321: return 0;
322: /* allocate a new cluster */
323: if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
324: (n_end - n_start) < s->cluster_sectors) {
325: /* if the cluster is already compressed, we must
326: decompress it in the case it is not completely
327: overwritten */
1.1.1.3 root 328: if (decompress_cluster(bs, cluster_offset) < 0)
1.1 root 329: return 0;
1.1.1.3 root 330: cluster_offset = bdrv_getlength(bs->file);
1.1 root 331: cluster_offset = (cluster_offset + s->cluster_size - 1) &
332: ~(s->cluster_size - 1);
333: /* write the cluster content */
1.1.1.3 root 334: if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
1.1 root 335: s->cluster_size)
336: return -1;
337: } else {
1.1.1.3 root 338: cluster_offset = bdrv_getlength(bs->file);
1.1 root 339: if (allocate == 1) {
340: /* round to cluster size */
341: cluster_offset = (cluster_offset + s->cluster_size - 1) &
342: ~(s->cluster_size - 1);
1.1.1.3 root 343: bdrv_truncate(bs->file, cluster_offset + s->cluster_size);
1.1 root 344: /* if encrypted, we must initialize the cluster
345: content which won't be written */
346: if (s->crypt_method &&
347: (n_end - n_start) < s->cluster_sectors) {
348: uint64_t start_sect;
349: start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
350: memset(s->cluster_data + 512, 0x00, 512);
351: for(i = 0; i < s->cluster_sectors; i++) {
352: if (i < n_start || i >= n_end) {
353: encrypt_sectors(s, start_sect + i,
354: s->cluster_data,
355: s->cluster_data + 512, 1, 1,
356: &s->aes_encrypt_key);
1.1.1.3 root 357: if (bdrv_pwrite(bs->file, cluster_offset + i * 512,
1.1 root 358: s->cluster_data, 512) != 512)
359: return -1;
360: }
361: }
362: }
363: } else if (allocate == 2) {
364: cluster_offset |= QCOW_OFLAG_COMPRESSED |
365: (uint64_t)compressed_size << (63 - s->cluster_bits);
366: }
367: }
368: /* update L2 table */
369: tmp = cpu_to_be64(cluster_offset);
370: l2_table[l2_index] = tmp;
1.1.1.3 root 371: if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
1.1.1.2 root 372: &tmp, sizeof(tmp)) < 0)
1.1 root 373: return 0;
374: }
375: return cluster_offset;
376: }
377:
378: static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
379: int nb_sectors, int *pnum)
380: {
381: BDRVQcowState *s = bs->opaque;
382: int index_in_cluster, n;
383: uint64_t cluster_offset;
384:
385: cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
386: index_in_cluster = sector_num & (s->cluster_sectors - 1);
387: n = s->cluster_sectors - index_in_cluster;
388: if (n > nb_sectors)
389: n = nb_sectors;
390: *pnum = n;
391: return (cluster_offset != 0);
392: }
393:
394: static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
395: const uint8_t *buf, int buf_size)
396: {
397: z_stream strm1, *strm = &strm1;
398: int ret, out_len;
399:
400: memset(strm, 0, sizeof(*strm));
401:
402: strm->next_in = (uint8_t *)buf;
403: strm->avail_in = buf_size;
404: strm->next_out = out_buf;
405: strm->avail_out = out_buf_size;
406:
407: ret = inflateInit2(strm, -12);
408: if (ret != Z_OK)
409: return -1;
410: ret = inflate(strm, Z_FINISH);
411: out_len = strm->next_out - out_buf;
412: if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
413: out_len != out_buf_size) {
414: inflateEnd(strm);
415: return -1;
416: }
417: inflateEnd(strm);
418: return 0;
419: }
420:
1.1.1.3 root 421: static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
1.1 root 422: {
1.1.1.3 root 423: BDRVQcowState *s = bs->opaque;
1.1 root 424: int ret, csize;
425: uint64_t coffset;
426:
427: coffset = cluster_offset & s->cluster_offset_mask;
428: if (s->cluster_cache_offset != coffset) {
429: csize = cluster_offset >> (63 - s->cluster_bits);
430: csize &= (s->cluster_size - 1);
1.1.1.3 root 431: ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
1.1 root 432: if (ret != csize)
433: return -1;
434: if (decompress_buffer(s->cluster_cache, s->cluster_size,
435: s->cluster_data, csize) < 0) {
436: return -1;
437: }
438: s->cluster_cache_offset = coffset;
439: }
440: return 0;
441: }
442:
443: #if 0
444:
445: static int qcow_read(BlockDriverState *bs, int64_t sector_num,
446: uint8_t *buf, int nb_sectors)
447: {
448: BDRVQcowState *s = bs->opaque;
449: int ret, index_in_cluster, n;
450: uint64_t cluster_offset;
451:
452: while (nb_sectors > 0) {
453: cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
454: index_in_cluster = sector_num & (s->cluster_sectors - 1);
455: n = s->cluster_sectors - index_in_cluster;
456: if (n > nb_sectors)
457: n = nb_sectors;
458: if (!cluster_offset) {
459: if (bs->backing_hd) {
460: /* read from the base image */
461: ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
462: if (ret < 0)
463: return -1;
464: } else {
465: memset(buf, 0, 512 * n);
466: }
467: } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
1.1.1.3 root 468: if (decompress_cluster(bs, cluster_offset) < 0)
1.1 root 469: return -1;
470: memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
471: } else {
1.1.1.3 root 472: ret = bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512);
1.1 root 473: if (ret != n * 512)
474: return -1;
475: if (s->crypt_method) {
476: encrypt_sectors(s, sector_num, buf, buf, n, 0,
477: &s->aes_decrypt_key);
478: }
479: }
480: nb_sectors -= n;
481: sector_num += n;
482: buf += n * 512;
483: }
484: return 0;
485: }
486: #endif
487:
488: typedef struct QCowAIOCB {
489: BlockDriverAIOCB common;
490: int64_t sector_num;
491: QEMUIOVector *qiov;
492: uint8_t *buf;
493: void *orig_buf;
494: int nb_sectors;
495: int n;
496: uint64_t cluster_offset;
497: uint8_t *cluster_data;
498: struct iovec hd_iov;
499: QEMUIOVector hd_qiov;
500: BlockDriverAIOCB *hd_aiocb;
501: } QCowAIOCB;
502:
503: static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
504: {
1.1.1.3 root 505: QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
1.1 root 506: if (acb->hd_aiocb)
507: bdrv_aio_cancel(acb->hd_aiocb);
508: qemu_aio_release(acb);
509: }
510:
511: static AIOPool qcow_aio_pool = {
512: .aiocb_size = sizeof(QCowAIOCB),
513: .cancel = qcow_aio_cancel,
514: };
515:
516: static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
517: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
518: BlockDriverCompletionFunc *cb, void *opaque, int is_write)
519: {
520: QCowAIOCB *acb;
521:
522: acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
523: if (!acb)
524: return NULL;
525: acb->hd_aiocb = NULL;
526: acb->sector_num = sector_num;
527: acb->qiov = qiov;
528: if (qiov->niov > 1) {
529: acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
530: if (is_write)
531: qemu_iovec_to_buffer(qiov, acb->buf);
532: } else {
533: acb->buf = (uint8_t *)qiov->iov->iov_base;
534: }
535: acb->nb_sectors = nb_sectors;
536: acb->n = 0;
537: acb->cluster_offset = 0;
538: return acb;
539: }
540:
541: static void qcow_aio_read_cb(void *opaque, int ret)
542: {
543: QCowAIOCB *acb = opaque;
544: BlockDriverState *bs = acb->common.bs;
545: BDRVQcowState *s = bs->opaque;
546: int index_in_cluster;
547:
548: acb->hd_aiocb = NULL;
549: if (ret < 0)
550: goto done;
551:
552: redo:
553: /* post process the read buffer */
554: if (!acb->cluster_offset) {
555: /* nothing to do */
556: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
557: /* nothing to do */
558: } else {
559: if (s->crypt_method) {
560: encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
561: acb->n, 0,
562: &s->aes_decrypt_key);
563: }
564: }
565:
566: acb->nb_sectors -= acb->n;
567: acb->sector_num += acb->n;
568: acb->buf += acb->n * 512;
569:
570: if (acb->nb_sectors == 0) {
571: /* request completed */
572: ret = 0;
573: goto done;
574: }
575:
576: /* prepare next AIO request */
577: acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
578: 0, 0, 0, 0);
579: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
580: acb->n = s->cluster_sectors - index_in_cluster;
581: if (acb->n > acb->nb_sectors)
582: acb->n = acb->nb_sectors;
583:
584: if (!acb->cluster_offset) {
585: if (bs->backing_hd) {
586: /* read from the base image */
587: acb->hd_iov.iov_base = (void *)acb->buf;
588: acb->hd_iov.iov_len = acb->n * 512;
589: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
590: acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
591: &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
592: if (acb->hd_aiocb == NULL)
593: goto done;
594: } else {
595: /* Note: in this case, no need to wait */
596: memset(acb->buf, 0, 512 * acb->n);
597: goto redo;
598: }
599: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
600: /* add AIO support for compressed blocks ? */
1.1.1.3 root 601: if (decompress_cluster(bs, acb->cluster_offset) < 0)
1.1 root 602: goto done;
603: memcpy(acb->buf,
604: s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
605: goto redo;
606: } else {
607: if ((acb->cluster_offset & 511) != 0) {
608: ret = -EIO;
609: goto done;
610: }
611: acb->hd_iov.iov_base = (void *)acb->buf;
612: acb->hd_iov.iov_len = acb->n * 512;
613: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 root 614: acb->hd_aiocb = bdrv_aio_readv(bs->file,
1.1 root 615: (acb->cluster_offset >> 9) + index_in_cluster,
616: &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
617: if (acb->hd_aiocb == NULL)
618: goto done;
619: }
620:
621: return;
622:
623: done:
624: if (acb->qiov->niov > 1) {
625: qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
626: qemu_vfree(acb->orig_buf);
627: }
628: acb->common.cb(acb->common.opaque, ret);
629: qemu_aio_release(acb);
630: }
631:
632: static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
633: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
634: BlockDriverCompletionFunc *cb, void *opaque)
635: {
636: QCowAIOCB *acb;
637:
638: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
639: if (!acb)
640: return NULL;
641:
642: qcow_aio_read_cb(acb, 0);
643: return &acb->common;
644: }
645:
646: static void qcow_aio_write_cb(void *opaque, int ret)
647: {
648: QCowAIOCB *acb = opaque;
649: BlockDriverState *bs = acb->common.bs;
650: BDRVQcowState *s = bs->opaque;
651: int index_in_cluster;
652: uint64_t cluster_offset;
653: const uint8_t *src_buf;
654:
655: acb->hd_aiocb = NULL;
656:
657: if (ret < 0)
658: goto done;
659:
660: acb->nb_sectors -= acb->n;
661: acb->sector_num += acb->n;
662: acb->buf += acb->n * 512;
663:
664: if (acb->nb_sectors == 0) {
665: /* request completed */
666: ret = 0;
667: goto done;
668: }
669:
670: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
671: acb->n = s->cluster_sectors - index_in_cluster;
672: if (acb->n > acb->nb_sectors)
673: acb->n = acb->nb_sectors;
674: cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0,
675: index_in_cluster,
676: index_in_cluster + acb->n);
677: if (!cluster_offset || (cluster_offset & 511) != 0) {
678: ret = -EIO;
679: goto done;
680: }
681: if (s->crypt_method) {
682: if (!acb->cluster_data) {
683: acb->cluster_data = qemu_mallocz(s->cluster_size);
684: if (!acb->cluster_data) {
685: ret = -ENOMEM;
686: goto done;
687: }
688: }
689: encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
690: acb->n, 1, &s->aes_encrypt_key);
691: src_buf = acb->cluster_data;
692: } else {
693: src_buf = acb->buf;
694: }
695:
696: acb->hd_iov.iov_base = (void *)src_buf;
697: acb->hd_iov.iov_len = acb->n * 512;
698: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 root 699: acb->hd_aiocb = bdrv_aio_writev(bs->file,
1.1 root 700: (cluster_offset >> 9) + index_in_cluster,
701: &acb->hd_qiov, acb->n,
702: qcow_aio_write_cb, acb);
703: if (acb->hd_aiocb == NULL)
704: goto done;
705: return;
706:
707: done:
708: if (acb->qiov->niov > 1)
709: qemu_vfree(acb->orig_buf);
710: acb->common.cb(acb->common.opaque, ret);
711: qemu_aio_release(acb);
712: }
713:
714: static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
715: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
716: BlockDriverCompletionFunc *cb, void *opaque)
717: {
718: BDRVQcowState *s = bs->opaque;
719: QCowAIOCB *acb;
720:
721: s->cluster_cache_offset = -1; /* disable compressed cache */
722:
723: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
724: if (!acb)
725: return NULL;
726:
727:
728: qcow_aio_write_cb(acb, 0);
729: return &acb->common;
730: }
731:
732: static void qcow_close(BlockDriverState *bs)
733: {
734: BDRVQcowState *s = bs->opaque;
735: qemu_free(s->l1_table);
736: qemu_free(s->l2_cache);
737: qemu_free(s->cluster_cache);
738: qemu_free(s->cluster_data);
739: }
740:
741: static int qcow_create(const char *filename, QEMUOptionParameter *options)
742: {
743: int fd, header_size, backing_filename_len, l1_size, i, shift;
744: QCowHeader header;
745: uint64_t tmp;
746: int64_t total_size = 0;
747: const char *backing_file = NULL;
748: int flags = 0;
1.1.1.3 root 749: int ret;
1.1 root 750:
751: /* Read out options */
752: while (options && options->name) {
753: if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
754: total_size = options->value.n / 512;
755: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
756: backing_file = options->value.s;
757: } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
758: flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
759: }
760: options++;
761: }
762:
763: fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
764: if (fd < 0)
1.1.1.3 root 765: return -errno;
1.1 root 766: memset(&header, 0, sizeof(header));
767: header.magic = cpu_to_be32(QCOW_MAGIC);
768: header.version = cpu_to_be32(QCOW_VERSION);
769: header.size = cpu_to_be64(total_size * 512);
770: header_size = sizeof(header);
771: backing_filename_len = 0;
772: if (backing_file) {
773: if (strcmp(backing_file, "fat:")) {
774: header.backing_file_offset = cpu_to_be64(header_size);
775: backing_filename_len = strlen(backing_file);
776: header.backing_file_size = cpu_to_be32(backing_filename_len);
777: header_size += backing_filename_len;
778: } else {
779: /* special backing file for vvfat */
780: backing_file = NULL;
781: }
782: header.cluster_bits = 9; /* 512 byte cluster to avoid copying
783: unmodifyed sectors */
784: header.l2_bits = 12; /* 32 KB L2 tables */
785: } else {
786: header.cluster_bits = 12; /* 4 KB clusters */
787: header.l2_bits = 9; /* 4 KB L2 tables */
788: }
789: header_size = (header_size + 7) & ~7;
790: shift = header.cluster_bits + header.l2_bits;
791: l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift;
792:
793: header.l1_table_offset = cpu_to_be64(header_size);
794: if (flags & BLOCK_FLAG_ENCRYPT) {
795: header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
796: } else {
797: header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
798: }
799:
800: /* write all the data */
1.1.1.3 root 801: ret = qemu_write_full(fd, &header, sizeof(header));
802: if (ret != sizeof(header)) {
803: ret = -errno;
804: goto exit;
805: }
806:
1.1 root 807: if (backing_file) {
1.1.1.3 root 808: ret = qemu_write_full(fd, backing_file, backing_filename_len);
809: if (ret != backing_filename_len) {
810: ret = -errno;
811: goto exit;
812: }
813:
1.1 root 814: }
815: lseek(fd, header_size, SEEK_SET);
816: tmp = 0;
817: for(i = 0;i < l1_size; i++) {
1.1.1.3 root 818: ret = qemu_write_full(fd, &tmp, sizeof(tmp));
819: if (ret != sizeof(tmp)) {
820: ret = -errno;
821: goto exit;
822: }
1.1 root 823: }
1.1.1.3 root 824:
825: ret = 0;
826: exit:
1.1 root 827: close(fd);
1.1.1.3 root 828: return ret;
1.1 root 829: }
830:
831: static int qcow_make_empty(BlockDriverState *bs)
832: {
833: BDRVQcowState *s = bs->opaque;
834: uint32_t l1_length = s->l1_size * sizeof(uint64_t);
835: int ret;
836:
837: memset(s->l1_table, 0, l1_length);
1.1.1.3 root 838: if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
1.1.1.2 root 839: l1_length) < 0)
840: return -1;
1.1.1.3 root 841: ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
1.1 root 842: if (ret < 0)
843: return ret;
844:
845: memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
846: memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
847: memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
848:
849: return 0;
850: }
851:
852: /* XXX: put compressed sectors first, then all the cluster aligned
853: tables to avoid losing bytes in alignment */
854: static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
855: const uint8_t *buf, int nb_sectors)
856: {
857: BDRVQcowState *s = bs->opaque;
858: z_stream strm;
859: int ret, out_len;
860: uint8_t *out_buf;
861: uint64_t cluster_offset;
862:
863: if (nb_sectors != s->cluster_sectors)
864: return -EINVAL;
865:
866: out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
867: if (!out_buf)
868: return -1;
869:
870: /* best compression, small window, no zlib header */
871: memset(&strm, 0, sizeof(strm));
872: ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
873: Z_DEFLATED, -12,
874: 9, Z_DEFAULT_STRATEGY);
875: if (ret != 0) {
876: qemu_free(out_buf);
877: return -1;
878: }
879:
880: strm.avail_in = s->cluster_size;
881: strm.next_in = (uint8_t *)buf;
882: strm.avail_out = s->cluster_size;
883: strm.next_out = out_buf;
884:
885: ret = deflate(&strm, Z_FINISH);
886: if (ret != Z_STREAM_END && ret != Z_OK) {
887: qemu_free(out_buf);
888: deflateEnd(&strm);
889: return -1;
890: }
891: out_len = strm.next_out - out_buf;
892:
893: deflateEnd(&strm);
894:
895: if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
896: /* could not compress: write normal cluster */
897: bdrv_write(bs, sector_num, buf, s->cluster_sectors);
898: } else {
899: cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
900: out_len, 0, 0);
901: cluster_offset &= s->cluster_offset_mask;
1.1.1.3 root 902: if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
1.1 root 903: qemu_free(out_buf);
904: return -1;
905: }
906: }
907:
908: qemu_free(out_buf);
909: return 0;
910: }
911:
1.1.1.4 ! root 912: static int qcow_flush(BlockDriverState *bs)
1.1 root 913: {
1.1.1.4 ! root 914: return bdrv_flush(bs->file);
1.1.1.3 root 915: }
916:
917: static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
918: BlockDriverCompletionFunc *cb, void *opaque)
919: {
920: return bdrv_aio_flush(bs->file, cb, opaque);
1.1 root 921: }
922:
923: static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
924: {
925: BDRVQcowState *s = bs->opaque;
926: bdi->cluster_size = s->cluster_size;
927: return 0;
928: }
929:
930:
931: static QEMUOptionParameter qcow_create_options[] = {
932: {
933: .name = BLOCK_OPT_SIZE,
934: .type = OPT_SIZE,
935: .help = "Virtual disk size"
936: },
937: {
938: .name = BLOCK_OPT_BACKING_FILE,
939: .type = OPT_STRING,
940: .help = "File name of a base image"
941: },
942: {
943: .name = BLOCK_OPT_ENCRYPT,
944: .type = OPT_FLAG,
945: .help = "Encrypt the image"
946: },
947: { NULL }
948: };
949:
950: static BlockDriver bdrv_qcow = {
951: .format_name = "qcow",
952: .instance_size = sizeof(BDRVQcowState),
953: .bdrv_probe = qcow_probe,
954: .bdrv_open = qcow_open,
955: .bdrv_close = qcow_close,
956: .bdrv_create = qcow_create,
957: .bdrv_flush = qcow_flush,
958: .bdrv_is_allocated = qcow_is_allocated,
959: .bdrv_set_key = qcow_set_key,
960: .bdrv_make_empty = qcow_make_empty,
961: .bdrv_aio_readv = qcow_aio_readv,
962: .bdrv_aio_writev = qcow_aio_writev,
1.1.1.3 root 963: .bdrv_aio_flush = qcow_aio_flush,
1.1 root 964: .bdrv_write_compressed = qcow_write_compressed,
965: .bdrv_get_info = qcow_get_info,
966:
967: .create_options = qcow_create_options,
968: };
969:
970: static void bdrv_qcow_init(void)
971: {
972: bdrv_register(&bdrv_qcow);
973: }
974:
975: block_init(bdrv_qcow_init);
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