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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;
1.1.1.5 ! root 499: bool is_write;
! 500: QEMUBH *bh;
1.1 root 501: QEMUIOVector hd_qiov;
502: BlockDriverAIOCB *hd_aiocb;
503: } QCowAIOCB;
504:
505: static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
506: {
1.1.1.3 root 507: QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
1.1 root 508: if (acb->hd_aiocb)
509: bdrv_aio_cancel(acb->hd_aiocb);
510: qemu_aio_release(acb);
511: }
512:
513: static AIOPool qcow_aio_pool = {
514: .aiocb_size = sizeof(QCowAIOCB),
515: .cancel = qcow_aio_cancel,
516: };
517:
518: static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
519: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
520: BlockDriverCompletionFunc *cb, void *opaque, int is_write)
521: {
522: QCowAIOCB *acb;
523:
524: acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
525: if (!acb)
526: return NULL;
527: acb->hd_aiocb = NULL;
528: acb->sector_num = sector_num;
529: acb->qiov = qiov;
1.1.1.5 ! root 530: acb->is_write = is_write;
! 531:
1.1 root 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:
1.1.1.5 ! root 545: static void qcow_aio_read_cb(void *opaque, int ret);
! 546: static void qcow_aio_write_cb(void *opaque, int ret);
! 547:
! 548: static void qcow_aio_rw_bh(void *opaque)
! 549: {
! 550: QCowAIOCB *acb = opaque;
! 551: qemu_bh_delete(acb->bh);
! 552: acb->bh = NULL;
! 553:
! 554: if (acb->is_write) {
! 555: qcow_aio_write_cb(opaque, 0);
! 556: } else {
! 557: qcow_aio_read_cb(opaque, 0);
! 558: }
! 559: }
! 560:
! 561: static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
! 562: {
! 563: if (acb->bh) {
! 564: return -EIO;
! 565: }
! 566:
! 567: acb->bh = qemu_bh_new(cb, acb);
! 568: if (!acb->bh) {
! 569: return -EIO;
! 570: }
! 571:
! 572: qemu_bh_schedule(acb->bh);
! 573:
! 574: return 0;
! 575: }
! 576:
1.1 root 577: static void qcow_aio_read_cb(void *opaque, int ret)
578: {
579: QCowAIOCB *acb = opaque;
580: BlockDriverState *bs = acb->common.bs;
581: BDRVQcowState *s = bs->opaque;
582: int index_in_cluster;
583:
584: acb->hd_aiocb = NULL;
585: if (ret < 0)
586: goto done;
587:
588: redo:
589: /* post process the read buffer */
590: if (!acb->cluster_offset) {
591: /* nothing to do */
592: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
593: /* nothing to do */
594: } else {
595: if (s->crypt_method) {
596: encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
597: acb->n, 0,
598: &s->aes_decrypt_key);
599: }
600: }
601:
602: acb->nb_sectors -= acb->n;
603: acb->sector_num += acb->n;
604: acb->buf += acb->n * 512;
605:
606: if (acb->nb_sectors == 0) {
607: /* request completed */
608: ret = 0;
609: goto done;
610: }
611:
612: /* prepare next AIO request */
613: acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
614: 0, 0, 0, 0);
615: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
616: acb->n = s->cluster_sectors - index_in_cluster;
617: if (acb->n > acb->nb_sectors)
618: acb->n = acb->nb_sectors;
619:
620: if (!acb->cluster_offset) {
621: if (bs->backing_hd) {
622: /* read from the base image */
623: acb->hd_iov.iov_base = (void *)acb->buf;
624: acb->hd_iov.iov_len = acb->n * 512;
625: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
626: acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
627: &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
1.1.1.5 ! root 628: if (acb->hd_aiocb == NULL) {
! 629: ret = -EIO;
1.1 root 630: goto done;
1.1.1.5 ! root 631: }
1.1 root 632: } else {
633: /* Note: in this case, no need to wait */
634: memset(acb->buf, 0, 512 * acb->n);
635: goto redo;
636: }
637: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
638: /* add AIO support for compressed blocks ? */
1.1.1.5 ! root 639: if (decompress_cluster(bs, acb->cluster_offset) < 0) {
! 640: ret = -EIO;
1.1 root 641: goto done;
1.1.1.5 ! root 642: }
1.1 root 643: memcpy(acb->buf,
644: s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
645: goto redo;
646: } else {
647: if ((acb->cluster_offset & 511) != 0) {
648: ret = -EIO;
649: goto done;
650: }
651: acb->hd_iov.iov_base = (void *)acb->buf;
652: acb->hd_iov.iov_len = acb->n * 512;
653: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 root 654: acb->hd_aiocb = bdrv_aio_readv(bs->file,
1.1 root 655: (acb->cluster_offset >> 9) + index_in_cluster,
656: &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
1.1.1.5 ! root 657: if (acb->hd_aiocb == NULL) {
! 658: ret = -EIO;
1.1 root 659: goto done;
1.1.1.5 ! root 660: }
1.1 root 661: }
662:
663: return;
664:
665: done:
666: if (acb->qiov->niov > 1) {
667: qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
668: qemu_vfree(acb->orig_buf);
669: }
670: acb->common.cb(acb->common.opaque, ret);
671: qemu_aio_release(acb);
672: }
673:
674: static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
675: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
676: BlockDriverCompletionFunc *cb, void *opaque)
677: {
678: QCowAIOCB *acb;
1.1.1.5 ! root 679: int ret;
1.1 root 680:
681: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
682: if (!acb)
683: return NULL;
684:
1.1.1.5 ! root 685: ret = qcow_schedule_bh(qcow_aio_rw_bh, acb);
! 686: if (ret < 0) {
! 687: if (acb->qiov->niov > 1) {
! 688: qemu_vfree(acb->orig_buf);
! 689: }
! 690: qemu_aio_release(acb);
! 691: return NULL;
! 692: }
! 693:
1.1 root 694: return &acb->common;
695: }
696:
697: static void qcow_aio_write_cb(void *opaque, int ret)
698: {
699: QCowAIOCB *acb = opaque;
700: BlockDriverState *bs = acb->common.bs;
701: BDRVQcowState *s = bs->opaque;
702: int index_in_cluster;
703: uint64_t cluster_offset;
704: const uint8_t *src_buf;
705:
706: acb->hd_aiocb = NULL;
707:
708: if (ret < 0)
709: goto done;
710:
711: acb->nb_sectors -= acb->n;
712: acb->sector_num += acb->n;
713: acb->buf += acb->n * 512;
714:
715: if (acb->nb_sectors == 0) {
716: /* request completed */
717: ret = 0;
718: goto done;
719: }
720:
721: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
722: acb->n = s->cluster_sectors - index_in_cluster;
723: if (acb->n > acb->nb_sectors)
724: acb->n = acb->nb_sectors;
725: cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0,
726: index_in_cluster,
727: index_in_cluster + acb->n);
728: if (!cluster_offset || (cluster_offset & 511) != 0) {
729: ret = -EIO;
730: goto done;
731: }
732: if (s->crypt_method) {
733: if (!acb->cluster_data) {
734: acb->cluster_data = qemu_mallocz(s->cluster_size);
735: if (!acb->cluster_data) {
736: ret = -ENOMEM;
737: goto done;
738: }
739: }
740: encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
741: acb->n, 1, &s->aes_encrypt_key);
742: src_buf = acb->cluster_data;
743: } else {
744: src_buf = acb->buf;
745: }
746:
747: acb->hd_iov.iov_base = (void *)src_buf;
748: acb->hd_iov.iov_len = acb->n * 512;
749: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 root 750: acb->hd_aiocb = bdrv_aio_writev(bs->file,
1.1 root 751: (cluster_offset >> 9) + index_in_cluster,
752: &acb->hd_qiov, acb->n,
753: qcow_aio_write_cb, acb);
1.1.1.5 ! root 754: if (acb->hd_aiocb == NULL) {
! 755: ret = -EIO;
1.1 root 756: goto done;
1.1.1.5 ! root 757: }
1.1 root 758: return;
759:
760: done:
761: if (acb->qiov->niov > 1)
762: qemu_vfree(acb->orig_buf);
763: acb->common.cb(acb->common.opaque, ret);
764: qemu_aio_release(acb);
765: }
766:
767: static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
768: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
769: BlockDriverCompletionFunc *cb, void *opaque)
770: {
771: BDRVQcowState *s = bs->opaque;
772: QCowAIOCB *acb;
1.1.1.5 ! root 773: int ret;
1.1 root 774:
775: s->cluster_cache_offset = -1; /* disable compressed cache */
776:
777: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
778: if (!acb)
779: return NULL;
780:
781:
1.1.1.5 ! root 782: ret = qcow_schedule_bh(qcow_aio_rw_bh, acb);
! 783: if (ret < 0) {
! 784: if (acb->qiov->niov > 1) {
! 785: qemu_vfree(acb->orig_buf);
! 786: }
! 787: qemu_aio_release(acb);
! 788: return NULL;
! 789: }
! 790:
1.1 root 791: return &acb->common;
792: }
793:
794: static void qcow_close(BlockDriverState *bs)
795: {
796: BDRVQcowState *s = bs->opaque;
797: qemu_free(s->l1_table);
798: qemu_free(s->l2_cache);
799: qemu_free(s->cluster_cache);
800: qemu_free(s->cluster_data);
801: }
802:
803: static int qcow_create(const char *filename, QEMUOptionParameter *options)
804: {
805: int fd, header_size, backing_filename_len, l1_size, i, shift;
806: QCowHeader header;
807: uint64_t tmp;
808: int64_t total_size = 0;
809: const char *backing_file = NULL;
810: int flags = 0;
1.1.1.3 root 811: int ret;
1.1 root 812:
813: /* Read out options */
814: while (options && options->name) {
815: if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
816: total_size = options->value.n / 512;
817: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
818: backing_file = options->value.s;
819: } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
820: flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
821: }
822: options++;
823: }
824:
825: fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
826: if (fd < 0)
1.1.1.3 root 827: return -errno;
1.1 root 828: memset(&header, 0, sizeof(header));
829: header.magic = cpu_to_be32(QCOW_MAGIC);
830: header.version = cpu_to_be32(QCOW_VERSION);
831: header.size = cpu_to_be64(total_size * 512);
832: header_size = sizeof(header);
833: backing_filename_len = 0;
834: if (backing_file) {
835: if (strcmp(backing_file, "fat:")) {
836: header.backing_file_offset = cpu_to_be64(header_size);
837: backing_filename_len = strlen(backing_file);
838: header.backing_file_size = cpu_to_be32(backing_filename_len);
839: header_size += backing_filename_len;
840: } else {
841: /* special backing file for vvfat */
842: backing_file = NULL;
843: }
844: header.cluster_bits = 9; /* 512 byte cluster to avoid copying
845: unmodifyed sectors */
846: header.l2_bits = 12; /* 32 KB L2 tables */
847: } else {
848: header.cluster_bits = 12; /* 4 KB clusters */
849: header.l2_bits = 9; /* 4 KB L2 tables */
850: }
851: header_size = (header_size + 7) & ~7;
852: shift = header.cluster_bits + header.l2_bits;
853: l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift;
854:
855: header.l1_table_offset = cpu_to_be64(header_size);
856: if (flags & BLOCK_FLAG_ENCRYPT) {
857: header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
858: } else {
859: header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
860: }
861:
862: /* write all the data */
1.1.1.3 root 863: ret = qemu_write_full(fd, &header, sizeof(header));
864: if (ret != sizeof(header)) {
865: ret = -errno;
866: goto exit;
867: }
868:
1.1 root 869: if (backing_file) {
1.1.1.3 root 870: ret = qemu_write_full(fd, backing_file, backing_filename_len);
871: if (ret != backing_filename_len) {
872: ret = -errno;
873: goto exit;
874: }
875:
1.1 root 876: }
877: lseek(fd, header_size, SEEK_SET);
878: tmp = 0;
879: for(i = 0;i < l1_size; i++) {
1.1.1.3 root 880: ret = qemu_write_full(fd, &tmp, sizeof(tmp));
881: if (ret != sizeof(tmp)) {
882: ret = -errno;
883: goto exit;
884: }
1.1 root 885: }
1.1.1.3 root 886:
887: ret = 0;
888: exit:
1.1 root 889: close(fd);
1.1.1.3 root 890: return ret;
1.1 root 891: }
892:
893: static int qcow_make_empty(BlockDriverState *bs)
894: {
895: BDRVQcowState *s = bs->opaque;
896: uint32_t l1_length = s->l1_size * sizeof(uint64_t);
897: int ret;
898:
899: memset(s->l1_table, 0, l1_length);
1.1.1.3 root 900: if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
1.1.1.2 root 901: l1_length) < 0)
902: return -1;
1.1.1.3 root 903: ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
1.1 root 904: if (ret < 0)
905: return ret;
906:
907: memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
908: memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
909: memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
910:
911: return 0;
912: }
913:
914: /* XXX: put compressed sectors first, then all the cluster aligned
915: tables to avoid losing bytes in alignment */
916: static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
917: const uint8_t *buf, int nb_sectors)
918: {
919: BDRVQcowState *s = bs->opaque;
920: z_stream strm;
921: int ret, out_len;
922: uint8_t *out_buf;
923: uint64_t cluster_offset;
924:
925: if (nb_sectors != s->cluster_sectors)
926: return -EINVAL;
927:
928: out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
929: if (!out_buf)
930: return -1;
931:
932: /* best compression, small window, no zlib header */
933: memset(&strm, 0, sizeof(strm));
934: ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
935: Z_DEFLATED, -12,
936: 9, Z_DEFAULT_STRATEGY);
937: if (ret != 0) {
938: qemu_free(out_buf);
939: return -1;
940: }
941:
942: strm.avail_in = s->cluster_size;
943: strm.next_in = (uint8_t *)buf;
944: strm.avail_out = s->cluster_size;
945: strm.next_out = out_buf;
946:
947: ret = deflate(&strm, Z_FINISH);
948: if (ret != Z_STREAM_END && ret != Z_OK) {
949: qemu_free(out_buf);
950: deflateEnd(&strm);
951: return -1;
952: }
953: out_len = strm.next_out - out_buf;
954:
955: deflateEnd(&strm);
956:
957: if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
958: /* could not compress: write normal cluster */
959: bdrv_write(bs, sector_num, buf, s->cluster_sectors);
960: } else {
961: cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
962: out_len, 0, 0);
963: cluster_offset &= s->cluster_offset_mask;
1.1.1.3 root 964: if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
1.1 root 965: qemu_free(out_buf);
966: return -1;
967: }
968: }
969:
970: qemu_free(out_buf);
971: return 0;
972: }
973:
1.1.1.4 root 974: static int qcow_flush(BlockDriverState *bs)
1.1 root 975: {
1.1.1.4 root 976: return bdrv_flush(bs->file);
1.1.1.3 root 977: }
978:
979: static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
980: BlockDriverCompletionFunc *cb, void *opaque)
981: {
982: return bdrv_aio_flush(bs->file, cb, opaque);
1.1 root 983: }
984:
985: static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
986: {
987: BDRVQcowState *s = bs->opaque;
988: bdi->cluster_size = s->cluster_size;
989: return 0;
990: }
991:
992:
993: static QEMUOptionParameter qcow_create_options[] = {
994: {
995: .name = BLOCK_OPT_SIZE,
996: .type = OPT_SIZE,
997: .help = "Virtual disk size"
998: },
999: {
1000: .name = BLOCK_OPT_BACKING_FILE,
1001: .type = OPT_STRING,
1002: .help = "File name of a base image"
1003: },
1004: {
1005: .name = BLOCK_OPT_ENCRYPT,
1006: .type = OPT_FLAG,
1007: .help = "Encrypt the image"
1008: },
1009: { NULL }
1010: };
1011:
1012: static BlockDriver bdrv_qcow = {
1013: .format_name = "qcow",
1014: .instance_size = sizeof(BDRVQcowState),
1015: .bdrv_probe = qcow_probe,
1016: .bdrv_open = qcow_open,
1017: .bdrv_close = qcow_close,
1018: .bdrv_create = qcow_create,
1019: .bdrv_flush = qcow_flush,
1020: .bdrv_is_allocated = qcow_is_allocated,
1021: .bdrv_set_key = qcow_set_key,
1022: .bdrv_make_empty = qcow_make_empty,
1023: .bdrv_aio_readv = qcow_aio_readv,
1024: .bdrv_aio_writev = qcow_aio_writev,
1.1.1.3 root 1025: .bdrv_aio_flush = qcow_aio_flush,
1.1 root 1026: .bdrv_write_compressed = qcow_write_compressed,
1027: .bdrv_get_info = qcow_get_info,
1028:
1029: .create_options = qcow_create_options,
1030: };
1031:
1032: static void bdrv_qcow_init(void)
1033: {
1034: bdrv_register(&bdrv_qcow);
1035: }
1036:
1037: block_init(bdrv_qcow_init);
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