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