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