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1.1 root 1: /*
2: * Block driver for the QCOW version 2 format
3: *
4: * Copyright (c) 2004-2006 Fabrice Bellard
5: *
6: * Permission is hereby granted, free of charge, to any person obtaining a copy
7: * of this software and associated documentation files (the "Software"), to deal
8: * in the Software without restriction, including without limitation the rights
9: * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10: * copies of the Software, and to permit persons to whom the Software is
11: * furnished to do so, subject to the following conditions:
12: *
13: * The above copyright notice and this permission notice shall be included in
14: * all copies or substantial portions of the Software.
15: *
16: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17: * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19: * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20: * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21: * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22: * THE SOFTWARE.
23: */
24: #include "qemu-common.h"
25: #include "block_int.h"
26: #include "module.h"
27: #include <zlib.h>
28: #include "aes.h"
29: #include "block/qcow2.h"
1.1.1.7 root 30: #include "qemu-error.h"
31: #include "qerror.h"
1.1 root 32:
33: /*
34: Differences with QCOW:
35:
36: - Support for multiple incremental snapshots.
37: - Memory management by reference counts.
38: - Clusters which have a reference count of one have the bit
39: QCOW_OFLAG_COPIED to optimize write performance.
40: - Size of compressed clusters is stored in sectors to reduce bit usage
41: in the cluster offsets.
42: - Support for storing additional data (such as the VM state) in the
43: snapshots.
44: - If a backing store is used, the cluster size is not constrained
45: (could be backported to QCOW).
46: - L2 tables have always a size of one cluster.
47: */
48:
49:
50: typedef struct {
51: uint32_t magic;
52: uint32_t len;
53: } QCowExtension;
1.1.1.7 root 54: #define QCOW2_EXT_MAGIC_END 0
55: #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
1.1 root 56:
1.1.1.7 root 57: static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
1.1 root 58: {
59: const QCowHeader *cow_header = (const void *)buf;
60:
61: if (buf_size >= sizeof(QCowHeader) &&
62: be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
1.1.1.7 root 63: be32_to_cpu(cow_header->version) >= QCOW_VERSION)
1.1 root 64: return 100;
65: else
66: return 0;
67: }
68:
69:
70: /*
71: * read qcow2 extension and fill bs
72: * start reading from start_offset
73: * finish reading upon magic of value 0 or when end_offset reached
74: * unknown magic is skipped (future extension this version knows nothing about)
75: * return 0 upon success, non-0 otherwise
76: */
1.1.1.7 root 77: static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
78: uint64_t end_offset)
1.1 root 79: {
80: QCowExtension ext;
81: uint64_t offset;
82:
83: #ifdef DEBUG_EXT
1.1.1.7 root 84: printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
1.1 root 85: #endif
86: offset = start_offset;
87: while (offset < end_offset) {
88:
89: #ifdef DEBUG_EXT
90: /* Sanity check */
91: if (offset > s->cluster_size)
1.1.1.7 root 92: printf("qcow2_read_extension: suspicious offset %lu\n", offset);
1.1 root 93:
94: printf("attemting to read extended header in offset %lu\n", offset);
95: #endif
96:
1.1.1.6 root 97: if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
1.1.1.7 root 98: fprintf(stderr, "qcow2_read_extension: ERROR: "
1.1.1.6 root 99: "pread fail from offset %" PRIu64 "\n",
100: offset);
1.1 root 101: return 1;
102: }
103: be32_to_cpus(&ext.magic);
104: be32_to_cpus(&ext.len);
105: offset += sizeof(ext);
106: #ifdef DEBUG_EXT
107: printf("ext.magic = 0x%x\n", ext.magic);
108: #endif
109: switch (ext.magic) {
1.1.1.7 root 110: case QCOW2_EXT_MAGIC_END:
1.1 root 111: return 0;
112:
1.1.1.7 root 113: case QCOW2_EXT_MAGIC_BACKING_FORMAT:
1.1 root 114: if (ext.len >= sizeof(bs->backing_format)) {
115: fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
116: " (>=%zu)\n",
117: ext.len, sizeof(bs->backing_format));
118: return 2;
119: }
1.1.1.6 root 120: if (bdrv_pread(bs->file, offset , bs->backing_format,
1.1 root 121: ext.len) != ext.len)
122: return 3;
123: bs->backing_format[ext.len] = '\0';
124: #ifdef DEBUG_EXT
125: printf("Qcow2: Got format extension %s\n", bs->backing_format);
126: #endif
1.1.1.2 root 127: offset = ((offset + ext.len + 7) & ~7);
1.1 root 128: break;
129:
130: default:
131: /* unknown magic -- just skip it */
1.1.1.2 root 132: offset = ((offset + ext.len + 7) & ~7);
1.1 root 133: break;
134: }
135: }
136:
137: return 0;
138: }
139:
140:
1.1.1.7 root 141: static int qcow2_open(BlockDriverState *bs, int flags)
1.1 root 142: {
143: BDRVQcowState *s = bs->opaque;
1.1.1.7 root 144: int len, i, ret = 0;
1.1 root 145: QCowHeader header;
146: uint64_t ext_end;
1.1.1.7 root 147: bool writethrough;
1.1 root 148:
1.1.1.7 root 149: ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
150: if (ret < 0) {
1.1 root 151: goto fail;
1.1.1.7 root 152: }
1.1 root 153: be32_to_cpus(&header.magic);
154: be32_to_cpus(&header.version);
155: be64_to_cpus(&header.backing_file_offset);
156: be32_to_cpus(&header.backing_file_size);
157: be64_to_cpus(&header.size);
158: be32_to_cpus(&header.cluster_bits);
159: be32_to_cpus(&header.crypt_method);
160: be64_to_cpus(&header.l1_table_offset);
161: be32_to_cpus(&header.l1_size);
162: be64_to_cpus(&header.refcount_table_offset);
163: be32_to_cpus(&header.refcount_table_clusters);
164: be64_to_cpus(&header.snapshots_offset);
165: be32_to_cpus(&header.nb_snapshots);
166:
1.1.1.7 root 167: if (header.magic != QCOW_MAGIC) {
168: ret = -EINVAL;
169: goto fail;
170: }
171: if (header.version != QCOW_VERSION) {
172: char version[64];
173: snprintf(version, sizeof(version), "QCOW version %d", header.version);
174: qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
175: bs->device_name, "qcow2", version);
176: ret = -ENOTSUP;
1.1 root 177: goto fail;
1.1.1.7 root 178: }
1.1.1.2 root 179: if (header.cluster_bits < MIN_CLUSTER_BITS ||
1.1.1.7 root 180: header.cluster_bits > MAX_CLUSTER_BITS) {
181: ret = -EINVAL;
1.1 root 182: goto fail;
1.1.1.7 root 183: }
184: if (header.crypt_method > QCOW_CRYPT_AES) {
185: ret = -EINVAL;
1.1 root 186: goto fail;
1.1.1.7 root 187: }
1.1 root 188: s->crypt_method_header = header.crypt_method;
1.1.1.7 root 189: if (s->crypt_method_header) {
1.1 root 190: bs->encrypted = 1;
1.1.1.7 root 191: }
1.1 root 192: s->cluster_bits = header.cluster_bits;
193: s->cluster_size = 1 << s->cluster_bits;
194: s->cluster_sectors = 1 << (s->cluster_bits - 9);
195: s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
196: s->l2_size = 1 << s->l2_bits;
197: bs->total_sectors = header.size / 512;
198: s->csize_shift = (62 - (s->cluster_bits - 8));
199: s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
200: s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
201: s->refcount_table_offset = header.refcount_table_offset;
202: s->refcount_table_size =
203: header.refcount_table_clusters << (s->cluster_bits - 3);
204:
205: s->snapshots_offset = header.snapshots_offset;
206: s->nb_snapshots = header.nb_snapshots;
207:
208: /* read the level 1 table */
209: s->l1_size = header.l1_size;
1.1.1.6 root 210: s->l1_vm_state_index = size_to_l1(s, header.size);
1.1 root 211: /* the L1 table must contain at least enough entries to put
212: header.size bytes */
1.1.1.7 root 213: if (s->l1_size < s->l1_vm_state_index) {
214: ret = -EINVAL;
1.1 root 215: goto fail;
1.1.1.7 root 216: }
1.1 root 217: s->l1_table_offset = header.l1_table_offset;
1.1.1.2 root 218: if (s->l1_size > 0) {
219: s->l1_table = qemu_mallocz(
220: align_offset(s->l1_size * sizeof(uint64_t), 512));
1.1.1.7 root 221: ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
222: s->l1_size * sizeof(uint64_t));
223: if (ret < 0) {
1.1.1.2 root 224: goto fail;
1.1.1.7 root 225: }
1.1.1.2 root 226: for(i = 0;i < s->l1_size; i++) {
227: be64_to_cpus(&s->l1_table[i]);
228: }
1.1 root 229: }
1.1.1.7 root 230:
231: /* alloc L2 table/refcount block cache */
1.1.1.8 ! root 232: writethrough = ((flags & BDRV_O_CACHE_WB) == 0);
1.1.1.7 root 233: s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, writethrough);
234: s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE,
235: writethrough);
236:
1.1 root 237: s->cluster_cache = qemu_malloc(s->cluster_size);
238: /* one more sector for decompressed data alignment */
239: s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
240: + 512);
241: s->cluster_cache_offset = -1;
242:
1.1.1.7 root 243: ret = qcow2_refcount_init(bs);
244: if (ret != 0) {
1.1 root 245: goto fail;
1.1.1.7 root 246: }
1.1 root 247:
1.1.1.2 root 248: QLIST_INIT(&s->cluster_allocs);
1.1 root 249:
250: /* read qcow2 extensions */
1.1.1.7 root 251: if (header.backing_file_offset) {
1.1 root 252: ext_end = header.backing_file_offset;
1.1.1.7 root 253: } else {
1.1 root 254: ext_end = s->cluster_size;
1.1.1.7 root 255: }
256: if (qcow2_read_extensions(bs, sizeof(header), ext_end)) {
257: ret = -EINVAL;
1.1 root 258: goto fail;
1.1.1.7 root 259: }
1.1 root 260:
261: /* read the backing file name */
262: if (header.backing_file_offset != 0) {
263: len = header.backing_file_size;
1.1.1.7 root 264: if (len > 1023) {
1.1 root 265: len = 1023;
1.1.1.7 root 266: }
267: ret = bdrv_pread(bs->file, header.backing_file_offset,
268: bs->backing_file, len);
269: if (ret < 0) {
1.1 root 270: goto fail;
1.1.1.7 root 271: }
1.1 root 272: bs->backing_file[len] = '\0';
273: }
1.1.1.7 root 274: if (qcow2_read_snapshots(bs) < 0) {
275: ret = -EINVAL;
1.1 root 276: goto fail;
1.1.1.7 root 277: }
1.1 root 278:
279: #ifdef DEBUG_ALLOC
280: qcow2_check_refcounts(bs);
281: #endif
1.1.1.7 root 282: return ret;
1.1 root 283:
284: fail:
285: qcow2_free_snapshots(bs);
286: qcow2_refcount_close(bs);
287: qemu_free(s->l1_table);
1.1.1.7 root 288: if (s->l2_table_cache) {
289: qcow2_cache_destroy(bs, s->l2_table_cache);
290: }
1.1 root 291: qemu_free(s->cluster_cache);
292: qemu_free(s->cluster_data);
1.1.1.7 root 293: return ret;
1.1 root 294: }
295:
1.1.1.7 root 296: static int qcow2_set_key(BlockDriverState *bs, const char *key)
1.1 root 297: {
298: BDRVQcowState *s = bs->opaque;
299: uint8_t keybuf[16];
300: int len, i;
301:
302: memset(keybuf, 0, 16);
303: len = strlen(key);
304: if (len > 16)
305: len = 16;
306: /* XXX: we could compress the chars to 7 bits to increase
307: entropy */
308: for(i = 0;i < len;i++) {
309: keybuf[i] = key[i];
310: }
311: s->crypt_method = s->crypt_method_header;
312:
313: if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
314: return -1;
315: if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
316: return -1;
317: #if 0
318: /* test */
319: {
320: uint8_t in[16];
321: uint8_t out[16];
322: uint8_t tmp[16];
323: for(i=0;i<16;i++)
324: in[i] = i;
325: AES_encrypt(in, tmp, &s->aes_encrypt_key);
326: AES_decrypt(tmp, out, &s->aes_decrypt_key);
327: for(i = 0; i < 16; i++)
328: printf(" %02x", tmp[i]);
329: printf("\n");
330: for(i = 0; i < 16; i++)
331: printf(" %02x", out[i]);
332: printf("\n");
333: }
334: #endif
335: return 0;
336: }
337:
1.1.1.7 root 338: static int qcow2_is_allocated(BlockDriverState *bs, int64_t sector_num,
339: int nb_sectors, int *pnum)
1.1 root 340: {
341: uint64_t cluster_offset;
1.1.1.6 root 342: int ret;
1.1 root 343:
344: *pnum = nb_sectors;
1.1.1.6 root 345: /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
346: * pass them on today */
347: ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
348: if (ret < 0) {
349: *pnum = 0;
350: }
1.1 root 351:
352: return (cluster_offset != 0);
353: }
354:
355: /* handle reading after the end of the backing file */
1.1.1.7 root 356: int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
357: int64_t sector_num, int nb_sectors)
1.1 root 358: {
359: int n1;
360: if ((sector_num + nb_sectors) <= bs->total_sectors)
361: return nb_sectors;
362: if (sector_num >= bs->total_sectors)
363: n1 = 0;
364: else
365: n1 = bs->total_sectors - sector_num;
1.1.1.7 root 366:
367: qemu_iovec_memset_skip(qiov, 0, 512 * (nb_sectors - n1), 512 * n1);
368:
1.1 root 369: return n1;
370: }
371:
372: typedef struct QCowAIOCB {
373: BlockDriverAIOCB common;
374: int64_t sector_num;
375: QEMUIOVector *qiov;
1.1.1.6 root 376: int remaining_sectors;
377: int cur_nr_sectors; /* number of sectors in current iteration */
1.1.1.7 root 378: uint64_t bytes_done;
1.1 root 379: uint64_t cluster_offset;
380: uint8_t *cluster_data;
1.1.1.8 ! root 381: bool is_write;
1.1 root 382: BlockDriverAIOCB *hd_aiocb;
383: QEMUIOVector hd_qiov;
384: QEMUBH *bh;
385: QCowL2Meta l2meta;
1.1.1.2 root 386: QLIST_ENTRY(QCowAIOCB) next_depend;
1.1 root 387: } QCowAIOCB;
388:
1.1.1.7 root 389: static void qcow2_aio_cancel(BlockDriverAIOCB *blockacb)
1.1 root 390: {
1.1.1.6 root 391: QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
1.1 root 392: if (acb->hd_aiocb)
393: bdrv_aio_cancel(acb->hd_aiocb);
394: qemu_aio_release(acb);
395: }
396:
1.1.1.7 root 397: static AIOPool qcow2_aio_pool = {
1.1 root 398: .aiocb_size = sizeof(QCowAIOCB),
1.1.1.7 root 399: .cancel = qcow2_aio_cancel,
1.1 root 400: };
401:
1.1.1.7 root 402: static void qcow2_aio_read_cb(void *opaque, int ret);
1.1.1.8 ! root 403: static void qcow2_aio_write_cb(void *opaque, int ret);
! 404:
! 405: static void qcow2_aio_rw_bh(void *opaque)
1.1 root 406: {
407: QCowAIOCB *acb = opaque;
408: qemu_bh_delete(acb->bh);
409: acb->bh = NULL;
1.1.1.8 ! root 410:
! 411: if (acb->is_write) {
! 412: qcow2_aio_write_cb(opaque, 0);
! 413: } else {
! 414: qcow2_aio_read_cb(opaque, 0);
! 415: }
1.1 root 416: }
417:
1.1.1.7 root 418: static int qcow2_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
1.1 root 419: {
420: if (acb->bh)
421: return -EIO;
422:
423: acb->bh = qemu_bh_new(cb, acb);
424: if (!acb->bh)
425: return -EIO;
426:
427: qemu_bh_schedule(acb->bh);
428:
429: return 0;
430: }
431:
1.1.1.7 root 432: static void qcow2_aio_read_cb(void *opaque, int ret)
1.1 root 433: {
434: QCowAIOCB *acb = opaque;
435: BlockDriverState *bs = acb->common.bs;
436: BDRVQcowState *s = bs->opaque;
437: int index_in_cluster, n1;
438:
439: acb->hd_aiocb = NULL;
440: if (ret < 0)
441: goto done;
442:
443: /* post process the read buffer */
444: if (!acb->cluster_offset) {
445: /* nothing to do */
446: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
447: /* nothing to do */
448: } else {
449: if (s->crypt_method) {
1.1.1.7 root 450: qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data,
451: acb->cluster_data, acb->cur_nr_sectors, 0, &s->aes_decrypt_key);
452: qemu_iovec_reset(&acb->hd_qiov);
453: qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done,
454: acb->cur_nr_sectors * 512);
455: qemu_iovec_from_buffer(&acb->hd_qiov, acb->cluster_data,
456: 512 * acb->cur_nr_sectors);
1.1 root 457: }
458: }
459:
1.1.1.6 root 460: acb->remaining_sectors -= acb->cur_nr_sectors;
461: acb->sector_num += acb->cur_nr_sectors;
1.1.1.7 root 462: acb->bytes_done += acb->cur_nr_sectors * 512;
1.1 root 463:
1.1.1.6 root 464: if (acb->remaining_sectors == 0) {
1.1 root 465: /* request completed */
466: ret = 0;
467: goto done;
468: }
469:
470: /* prepare next AIO request */
1.1.1.6 root 471: acb->cur_nr_sectors = acb->remaining_sectors;
1.1.1.7 root 472: if (s->crypt_method) {
473: acb->cur_nr_sectors = MIN(acb->cur_nr_sectors,
474: QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
475: }
476:
1.1.1.6 root 477: ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
478: &acb->cur_nr_sectors, &acb->cluster_offset);
479: if (ret < 0) {
480: goto done;
481: }
482:
1.1 root 483: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
484:
1.1.1.7 root 485: qemu_iovec_reset(&acb->hd_qiov);
486: qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done,
487: acb->cur_nr_sectors * 512);
488:
1.1 root 489: if (!acb->cluster_offset) {
1.1.1.7 root 490:
1.1 root 491: if (bs->backing_hd) {
492: /* read from the base image */
1.1.1.7 root 493: n1 = qcow2_backing_read1(bs->backing_hd, &acb->hd_qiov,
494: acb->sector_num, acb->cur_nr_sectors);
1.1 root 495: if (n1 > 0) {
1.1.1.6 root 496: BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
1.1 root 497: acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
1.1.1.7 root 498: &acb->hd_qiov, n1, qcow2_aio_read_cb, acb);
499: if (acb->hd_aiocb == NULL) {
500: ret = -EIO;
1.1 root 501: goto done;
1.1.1.7 root 502: }
1.1 root 503: } else {
1.1.1.8 ! root 504: ret = qcow2_schedule_bh(qcow2_aio_rw_bh, acb);
1.1 root 505: if (ret < 0)
506: goto done;
507: }
508: } else {
509: /* Note: in this case, no need to wait */
1.1.1.7 root 510: qemu_iovec_memset(&acb->hd_qiov, 0, 512 * acb->cur_nr_sectors);
1.1.1.8 ! root 511: ret = qcow2_schedule_bh(qcow2_aio_rw_bh, acb);
1.1 root 512: if (ret < 0)
513: goto done;
514: }
515: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
516: /* add AIO support for compressed blocks ? */
1.1.1.7 root 517: ret = qcow2_decompress_cluster(bs, acb->cluster_offset);
518: if (ret < 0) {
1.1 root 519: goto done;
1.1.1.7 root 520: }
521:
522: qemu_iovec_from_buffer(&acb->hd_qiov,
523: s->cluster_cache + index_in_cluster * 512,
524: 512 * acb->cur_nr_sectors);
525:
1.1.1.8 ! root 526: ret = qcow2_schedule_bh(qcow2_aio_rw_bh, acb);
1.1 root 527: if (ret < 0)
528: goto done;
529: } else {
530: if ((acb->cluster_offset & 511) != 0) {
531: ret = -EIO;
532: goto done;
533: }
534:
1.1.1.7 root 535: if (s->crypt_method) {
536: /*
537: * For encrypted images, read everything into a temporary
538: * contiguous buffer on which the AES functions can work.
539: */
540: if (!acb->cluster_data) {
541: acb->cluster_data =
542: qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
543: }
544:
545: assert(acb->cur_nr_sectors <=
546: QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
547: qemu_iovec_reset(&acb->hd_qiov);
548: qemu_iovec_add(&acb->hd_qiov, acb->cluster_data,
549: 512 * acb->cur_nr_sectors);
550: }
551:
1.1.1.6 root 552: BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
553: acb->hd_aiocb = bdrv_aio_readv(bs->file,
1.1 root 554: (acb->cluster_offset >> 9) + index_in_cluster,
1.1.1.6 root 555: &acb->hd_qiov, acb->cur_nr_sectors,
1.1.1.7 root 556: qcow2_aio_read_cb, acb);
1.1.1.4 root 557: if (acb->hd_aiocb == NULL) {
558: ret = -EIO;
1.1 root 559: goto done;
1.1.1.4 root 560: }
1.1 root 561: }
562:
563: return;
564: done:
565: acb->common.cb(acb->common.opaque, ret);
1.1.1.7 root 566: qemu_iovec_destroy(&acb->hd_qiov);
1.1 root 567: qemu_aio_release(acb);
568: }
569:
1.1.1.7 root 570: static QCowAIOCB *qcow2_aio_setup(BlockDriverState *bs, int64_t sector_num,
571: QEMUIOVector *qiov, int nb_sectors,
572: BlockDriverCompletionFunc *cb,
573: void *opaque, int is_write)
1.1 root 574: {
575: QCowAIOCB *acb;
576:
1.1.1.7 root 577: acb = qemu_aio_get(&qcow2_aio_pool, bs, cb, opaque);
1.1 root 578: if (!acb)
579: return NULL;
580: acb->hd_aiocb = NULL;
581: acb->sector_num = sector_num;
582: acb->qiov = qiov;
1.1.1.8 ! root 583: acb->is_write = is_write;
1.1.1.7 root 584:
585: qemu_iovec_init(&acb->hd_qiov, qiov->niov);
586:
587: acb->bytes_done = 0;
1.1.1.6 root 588: acb->remaining_sectors = nb_sectors;
589: acb->cur_nr_sectors = 0;
1.1 root 590: acb->cluster_offset = 0;
591: acb->l2meta.nb_clusters = 0;
1.1.1.2 root 592: QLIST_INIT(&acb->l2meta.dependent_requests);
1.1 root 593: return acb;
594: }
595:
1.1.1.7 root 596: static BlockDriverAIOCB *qcow2_aio_readv(BlockDriverState *bs,
597: int64_t sector_num,
598: QEMUIOVector *qiov, int nb_sectors,
599: BlockDriverCompletionFunc *cb,
600: void *opaque)
1.1 root 601: {
602: QCowAIOCB *acb;
1.1.1.8 ! root 603: int ret;
1.1 root 604:
1.1.1.7 root 605: acb = qcow2_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
1.1 root 606: if (!acb)
607: return NULL;
608:
1.1.1.8 ! root 609: ret = qcow2_schedule_bh(qcow2_aio_rw_bh, acb);
! 610: if (ret < 0) {
! 611: qemu_iovec_destroy(&acb->hd_qiov);
! 612: qemu_aio_release(acb);
! 613: return NULL;
! 614: }
! 615:
1.1 root 616: return &acb->common;
617: }
618:
619: static void run_dependent_requests(QCowL2Meta *m)
620: {
621: QCowAIOCB *req;
622: QCowAIOCB *next;
623:
624: /* Take the request off the list of running requests */
625: if (m->nb_clusters != 0) {
1.1.1.2 root 626: QLIST_REMOVE(m, next_in_flight);
1.1 root 627: }
628:
1.1.1.6 root 629: /* Restart all dependent requests */
630: QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) {
1.1.1.7 root 631: qcow2_aio_write_cb(req, 0);
1.1 root 632: }
633:
634: /* Empty the list for the next part of the request */
1.1.1.2 root 635: QLIST_INIT(&m->dependent_requests);
1.1 root 636: }
637:
1.1.1.7 root 638: static void qcow2_aio_write_cb(void *opaque, int ret)
1.1 root 639: {
640: QCowAIOCB *acb = opaque;
641: BlockDriverState *bs = acb->common.bs;
642: BDRVQcowState *s = bs->opaque;
643: int index_in_cluster;
644: int n_end;
645:
646: acb->hd_aiocb = NULL;
647:
648: if (ret >= 0) {
1.1.1.3 root 649: ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta);
1.1 root 650: }
651:
652: run_dependent_requests(&acb->l2meta);
653:
654: if (ret < 0)
655: goto done;
656:
1.1.1.6 root 657: acb->remaining_sectors -= acb->cur_nr_sectors;
658: acb->sector_num += acb->cur_nr_sectors;
1.1.1.7 root 659: acb->bytes_done += acb->cur_nr_sectors * 512;
1.1 root 660:
1.1.1.6 root 661: if (acb->remaining_sectors == 0) {
1.1 root 662: /* request completed */
663: ret = 0;
664: goto done;
665: }
666:
667: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
1.1.1.6 root 668: n_end = index_in_cluster + acb->remaining_sectors;
1.1 root 669: if (s->crypt_method &&
670: n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
671: n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
672:
1.1.1.3 root 673: ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
1.1.1.6 root 674: index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta);
1.1.1.3 root 675: if (ret < 0) {
676: goto done;
677: }
678:
679: acb->cluster_offset = acb->l2meta.cluster_offset;
1.1 root 680:
681: /* Need to wait for another request? If so, we are done for now. */
1.1.1.3 root 682: if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) {
1.1.1.2 root 683: QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests,
1.1 root 684: acb, next_depend);
685: return;
686: }
687:
1.1.1.3 root 688: assert((acb->cluster_offset & 511) == 0);
689:
1.1.1.7 root 690: qemu_iovec_reset(&acb->hd_qiov);
691: qemu_iovec_copy(&acb->hd_qiov, acb->qiov, acb->bytes_done,
692: acb->cur_nr_sectors * 512);
693:
1.1 root 694: if (s->crypt_method) {
695: if (!acb->cluster_data) {
696: acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
697: s->cluster_size);
698: }
1.1.1.7 root 699:
700: assert(acb->hd_qiov.size <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
701: qemu_iovec_to_buffer(&acb->hd_qiov, acb->cluster_data);
702:
703: qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data,
704: acb->cluster_data, acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
705:
706: qemu_iovec_reset(&acb->hd_qiov);
707: qemu_iovec_add(&acb->hd_qiov, acb->cluster_data,
708: acb->cur_nr_sectors * 512);
1.1 root 709: }
1.1.1.7 root 710:
1.1.1.6 root 711: BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
712: acb->hd_aiocb = bdrv_aio_writev(bs->file,
1.1 root 713: (acb->cluster_offset >> 9) + index_in_cluster,
1.1.1.6 root 714: &acb->hd_qiov, acb->cur_nr_sectors,
1.1.1.7 root 715: qcow2_aio_write_cb, acb);
1.1.1.4 root 716: if (acb->hd_aiocb == NULL) {
717: ret = -EIO;
718: goto fail;
719: }
1.1 root 720:
721: return;
722:
1.1.1.4 root 723: fail:
724: if (acb->l2meta.nb_clusters != 0) {
725: QLIST_REMOVE(&acb->l2meta, next_in_flight);
726: }
1.1 root 727: done:
728: acb->common.cb(acb->common.opaque, ret);
1.1.1.7 root 729: qemu_iovec_destroy(&acb->hd_qiov);
1.1 root 730: qemu_aio_release(acb);
731: }
732:
1.1.1.7 root 733: static BlockDriverAIOCB *qcow2_aio_writev(BlockDriverState *bs,
734: int64_t sector_num,
735: QEMUIOVector *qiov, int nb_sectors,
736: BlockDriverCompletionFunc *cb,
737: void *opaque)
1.1 root 738: {
739: BDRVQcowState *s = bs->opaque;
740: QCowAIOCB *acb;
1.1.1.8 ! root 741: int ret;
1.1 root 742:
743: s->cluster_cache_offset = -1; /* disable compressed cache */
744:
1.1.1.7 root 745: acb = qcow2_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
1.1 root 746: if (!acb)
747: return NULL;
748:
1.1.1.8 ! root 749: ret = qcow2_schedule_bh(qcow2_aio_rw_bh, acb);
! 750: if (ret < 0) {
! 751: qemu_iovec_destroy(&acb->hd_qiov);
! 752: qemu_aio_release(acb);
! 753: return NULL;
! 754: }
! 755:
1.1 root 756: return &acb->common;
757: }
758:
1.1.1.7 root 759: static void qcow2_close(BlockDriverState *bs)
1.1 root 760: {
761: BDRVQcowState *s = bs->opaque;
762: qemu_free(s->l1_table);
1.1.1.7 root 763:
764: qcow2_cache_flush(bs, s->l2_table_cache);
765: qcow2_cache_flush(bs, s->refcount_block_cache);
766:
767: qcow2_cache_destroy(bs, s->l2_table_cache);
768: qcow2_cache_destroy(bs, s->refcount_block_cache);
769:
1.1 root 770: qemu_free(s->cluster_cache);
771: qemu_free(s->cluster_data);
772: qcow2_refcount_close(bs);
1.1.1.6 root 773: }
774:
775: /*
776: * Updates the variable length parts of the qcow2 header, i.e. the backing file
777: * name and all extensions. qcow2 was not designed to allow such changes, so if
778: * we run out of space (we can only use the first cluster) this function may
779: * fail.
780: *
781: * Returns 0 on success, -errno in error cases.
782: */
783: static int qcow2_update_ext_header(BlockDriverState *bs,
784: const char *backing_file, const char *backing_fmt)
785: {
786: size_t backing_file_len = 0;
787: size_t backing_fmt_len = 0;
788: BDRVQcowState *s = bs->opaque;
789: QCowExtension ext_backing_fmt = {0, 0};
790: int ret;
791:
792: /* Backing file format doesn't make sense without a backing file */
793: if (backing_fmt && !backing_file) {
794: return -EINVAL;
795: }
796:
797: /* Prepare the backing file format extension if needed */
798: if (backing_fmt) {
799: ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
1.1.1.7 root 800: ext_backing_fmt.magic = cpu_to_be32(QCOW2_EXT_MAGIC_BACKING_FORMAT);
1.1.1.6 root 801: backing_fmt_len = ((sizeof(ext_backing_fmt)
802: + strlen(backing_fmt) + 7) & ~7);
803: }
804:
805: /* Check if we can fit the new header into the first cluster */
806: if (backing_file) {
807: backing_file_len = strlen(backing_file);
808: }
809:
810: size_t header_size = sizeof(QCowHeader) + backing_file_len
811: + backing_fmt_len;
812:
813: if (header_size > s->cluster_size) {
814: return -ENOSPC;
815: }
816:
817: /* Rewrite backing file name and qcow2 extensions */
818: size_t ext_size = header_size - sizeof(QCowHeader);
819: uint8_t buf[ext_size];
820: size_t offset = 0;
821: size_t backing_file_offset = 0;
822:
823: if (backing_file) {
824: if (backing_fmt) {
825: int padding = backing_fmt_len -
826: (sizeof(ext_backing_fmt) + strlen(backing_fmt));
827:
828: memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
829: offset += sizeof(ext_backing_fmt);
830:
831: memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
832: offset += strlen(backing_fmt);
833:
834: memset(buf + offset, 0, padding);
835: offset += padding;
836: }
837:
838: memcpy(buf + offset, backing_file, backing_file_len);
839: backing_file_offset = sizeof(QCowHeader) + offset;
840: }
841:
842: ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
843: if (ret < 0) {
844: goto fail;
845: }
846:
847: /* Update header fields */
848: uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
849: uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
850:
851: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
852: &be_backing_file_offset, sizeof(uint64_t));
853: if (ret < 0) {
854: goto fail;
855: }
856:
857: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
858: &be_backing_file_size, sizeof(uint32_t));
859: if (ret < 0) {
860: goto fail;
861: }
862:
863: ret = 0;
864: fail:
865: return ret;
866: }
867:
868: static int qcow2_change_backing_file(BlockDriverState *bs,
869: const char *backing_file, const char *backing_fmt)
870: {
871: return qcow2_update_ext_header(bs, backing_file, backing_fmt);
1.1 root 872: }
873:
1.1.1.2 root 874: static int preallocate(BlockDriverState *bs)
875: {
876: uint64_t nb_sectors;
877: uint64_t offset;
878: int num;
1.1.1.3 root 879: int ret;
1.1.1.2 root 880: QCowL2Meta meta;
881:
882: nb_sectors = bdrv_getlength(bs) >> 9;
883: offset = 0;
884: QLIST_INIT(&meta.dependent_requests);
1.1.1.3 root 885: meta.cluster_offset = 0;
1.1.1.2 root 886:
887: while (nb_sectors) {
888: num = MIN(nb_sectors, INT_MAX >> 9);
1.1.1.3 root 889: ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
890: if (ret < 0) {
1.1.1.6 root 891: return ret;
1.1.1.2 root 892: }
893:
1.1.1.6 root 894: ret = qcow2_alloc_cluster_link_l2(bs, &meta);
895: if (ret < 0) {
1.1.1.3 root 896: qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
1.1.1.6 root 897: return ret;
1.1.1.2 root 898: }
899:
900: /* There are no dependent requests, but we need to remove our request
901: * from the list of in-flight requests */
902: run_dependent_requests(&meta);
903:
904: /* TODO Preallocate data if requested */
905:
906: nb_sectors -= num;
907: offset += num << 9;
908: }
909:
910: /*
911: * It is expected that the image file is large enough to actually contain
912: * all of the allocated clusters (otherwise we get failing reads after
913: * EOF). Extend the image to the last allocated sector.
914: */
1.1.1.3 root 915: if (meta.cluster_offset != 0) {
1.1.1.2 root 916: uint8_t buf[512];
917: memset(buf, 0, 512);
1.1.1.6 root 918: ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
919: if (ret < 0) {
920: return ret;
921: }
1.1.1.2 root 922: }
923:
924: return 0;
925: }
926:
1.1.1.7 root 927: static int qcow2_create2(const char *filename, int64_t total_size,
928: const char *backing_file, const char *backing_format,
929: int flags, size_t cluster_size, int prealloc,
930: QEMUOptionParameter *options)
931: {
932: /* Calulate cluster_bits */
933: int cluster_bits;
934: cluster_bits = ffs(cluster_size) - 1;
935: if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
936: (1 << cluster_bits) != cluster_size)
937: {
938: error_report(
1.1.1.8 ! root 939: "Cluster size must be a power of two between %d and %dk",
1.1.1.7 root 940: 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
941: return -EINVAL;
942: }
1.1 root 943:
1.1.1.7 root 944: /*
945: * Open the image file and write a minimal qcow2 header.
946: *
947: * We keep things simple and start with a zero-sized image. We also
948: * do without refcount blocks or a L1 table for now. We'll fix the
949: * inconsistency later.
950: *
951: * We do need a refcount table because growing the refcount table means
952: * allocating two new refcount blocks - the seconds of which would be at
953: * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
954: * size for any qcow2 image.
955: */
956: BlockDriverState* bs;
1.1 root 957: QCowHeader header;
1.1.1.7 root 958: uint8_t* refcount_table;
1.1.1.6 root 959: int ret;
1.1 root 960:
1.1.1.7 root 961: ret = bdrv_create_file(filename, options);
962: if (ret < 0) {
963: return ret;
964: }
965:
966: ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR);
967: if (ret < 0) {
968: return ret;
969: }
1.1 root 970:
1.1.1.7 root 971: /* Write the header */
1.1 root 972: memset(&header, 0, sizeof(header));
973: header.magic = cpu_to_be32(QCOW_MAGIC);
974: header.version = cpu_to_be32(QCOW_VERSION);
1.1.1.7 root 975: header.cluster_bits = cpu_to_be32(cluster_bits);
976: header.size = cpu_to_be64(0);
977: header.l1_table_offset = cpu_to_be64(0);
978: header.l1_size = cpu_to_be32(0);
979: header.refcount_table_offset = cpu_to_be64(cluster_size);
980: header.refcount_table_clusters = cpu_to_be32(1);
1.1 root 981:
982: if (flags & BLOCK_FLAG_ENCRYPT) {
983: header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
984: } else {
985: header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
986: }
1.1.1.7 root 987:
988: ret = bdrv_pwrite(bs, 0, &header, sizeof(header));
989: if (ret < 0) {
990: goto out;
991: }
992:
993: /* Write an empty refcount table */
994: refcount_table = qemu_mallocz(cluster_size);
995: ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size);
996: qemu_free(refcount_table);
997:
998: if (ret < 0) {
999: goto out;
1000: }
1001:
1002: bdrv_close(bs);
1003:
1004: /*
1005: * And now open the image and make it consistent first (i.e. increase the
1006: * refcount of the cluster that is occupied by the header and the refcount
1007: * table)
1008: */
1009: BlockDriver* drv = bdrv_find_format("qcow2");
1010: assert(drv != NULL);
1011: ret = bdrv_open(bs, filename,
1012: BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv);
1013: if (ret < 0) {
1014: goto out;
1015: }
1016:
1017: ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
1018: if (ret < 0) {
1019: goto out;
1020:
1021: } else if (ret != 0) {
1022: error_report("Huh, first cluster in empty image is already in use?");
1023: abort();
1024: }
1025:
1026: /* Okay, now that we have a valid image, let's give it the right size */
1027: ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE);
1028: if (ret < 0) {
1029: goto out;
1.1.1.6 root 1030: }
1.1.1.7 root 1031:
1032: /* Want a backing file? There you go.*/
1.1 root 1033: if (backing_file) {
1.1.1.7 root 1034: ret = bdrv_change_backing_file(bs, backing_file, backing_format);
1035: if (ret < 0) {
1036: goto out;
1.1 root 1037: }
1.1.1.6 root 1038: }
1.1 root 1039:
1.1.1.7 root 1040: /* And if we're supposed to preallocate metadata, do that now */
1041: if (prealloc) {
1.1.1.6 root 1042: ret = preallocate(bs);
1.1.1.7 root 1043: if (ret < 0) {
1044: goto out;
1045: }
1.1.1.2 root 1046: }
1047:
1.1.1.7 root 1048: ret = 0;
1049: out:
1050: bdrv_delete(bs);
1.1.1.6 root 1051: return ret;
1.1 root 1052: }
1053:
1.1.1.7 root 1054: static int qcow2_create(const char *filename, QEMUOptionParameter *options)
1.1 root 1055: {
1056: const char *backing_file = NULL;
1057: const char *backing_fmt = NULL;
1058: uint64_t sectors = 0;
1059: int flags = 0;
1.1.1.8 ! root 1060: size_t cluster_size = DEFAULT_CLUSTER_SIZE;
1.1.1.2 root 1061: int prealloc = 0;
1.1 root 1062:
1063: /* Read out options */
1064: while (options && options->name) {
1065: if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
1066: sectors = options->value.n / 512;
1067: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
1068: backing_file = options->value.s;
1069: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
1070: backing_fmt = options->value.s;
1071: } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
1072: flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
1073: } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
1074: if (options->value.n) {
1075: cluster_size = options->value.n;
1076: }
1.1.1.2 root 1077: } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
1078: if (!options->value.s || !strcmp(options->value.s, "off")) {
1079: prealloc = 0;
1080: } else if (!strcmp(options->value.s, "metadata")) {
1081: prealloc = 1;
1082: } else {
1083: fprintf(stderr, "Invalid preallocation mode: '%s'\n",
1084: options->value.s);
1085: return -EINVAL;
1086: }
1.1 root 1087: }
1088: options++;
1089: }
1090:
1.1.1.2 root 1091: if (backing_file && prealloc) {
1092: fprintf(stderr, "Backing file and preallocation cannot be used at "
1093: "the same time\n");
1094: return -EINVAL;
1095: }
1096:
1.1.1.7 root 1097: return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
1098: cluster_size, prealloc, options);
1.1 root 1099: }
1100:
1.1.1.7 root 1101: static int qcow2_make_empty(BlockDriverState *bs)
1.1 root 1102: {
1103: #if 0
1104: /* XXX: not correct */
1105: BDRVQcowState *s = bs->opaque;
1106: uint32_t l1_length = s->l1_size * sizeof(uint64_t);
1107: int ret;
1108:
1109: memset(s->l1_table, 0, l1_length);
1.1.1.6 root 1110: if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
1.1 root 1111: return -1;
1.1.1.6 root 1112: ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
1.1 root 1113: if (ret < 0)
1114: return ret;
1115:
1116: l2_cache_reset(bs);
1117: #endif
1118: return 0;
1119: }
1120:
1.1.1.7 root 1121: static int qcow2_discard(BlockDriverState *bs, int64_t sector_num,
1122: int nb_sectors)
1123: {
1124: return qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS,
1125: nb_sectors);
1126: }
1127:
1.1.1.6 root 1128: static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
1129: {
1130: BDRVQcowState *s = bs->opaque;
1131: int ret, new_l1_size;
1132:
1133: if (offset & 511) {
1134: return -EINVAL;
1135: }
1136:
1137: /* cannot proceed if image has snapshots */
1138: if (s->nb_snapshots) {
1139: return -ENOTSUP;
1140: }
1141:
1142: /* shrinking is currently not supported */
1143: if (offset < bs->total_sectors * 512) {
1144: return -ENOTSUP;
1145: }
1146:
1147: new_l1_size = size_to_l1(s, offset);
1.1.1.7 root 1148: ret = qcow2_grow_l1_table(bs, new_l1_size, true);
1.1.1.6 root 1149: if (ret < 0) {
1150: return ret;
1151: }
1152:
1153: /* write updated header.size */
1154: offset = cpu_to_be64(offset);
1155: ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
1156: &offset, sizeof(uint64_t));
1157: if (ret < 0) {
1158: return ret;
1159: }
1160:
1161: s->l1_vm_state_index = new_l1_size;
1162: return 0;
1163: }
1164:
1.1 root 1165: /* XXX: put compressed sectors first, then all the cluster aligned
1166: tables to avoid losing bytes in alignment */
1.1.1.7 root 1167: static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num,
1168: const uint8_t *buf, int nb_sectors)
1.1 root 1169: {
1170: BDRVQcowState *s = bs->opaque;
1171: z_stream strm;
1172: int ret, out_len;
1173: uint8_t *out_buf;
1174: uint64_t cluster_offset;
1175:
1176: if (nb_sectors == 0) {
1177: /* align end of file to a sector boundary to ease reading with
1178: sector based I/Os */
1.1.1.6 root 1179: cluster_offset = bdrv_getlength(bs->file);
1.1 root 1180: cluster_offset = (cluster_offset + 511) & ~511;
1.1.1.6 root 1181: bdrv_truncate(bs->file, cluster_offset);
1.1 root 1182: return 0;
1183: }
1184:
1185: if (nb_sectors != s->cluster_sectors)
1186: return -EINVAL;
1187:
1188: out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
1189:
1190: /* best compression, small window, no zlib header */
1191: memset(&strm, 0, sizeof(strm));
1192: ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
1193: Z_DEFLATED, -12,
1194: 9, Z_DEFAULT_STRATEGY);
1195: if (ret != 0) {
1196: qemu_free(out_buf);
1197: return -1;
1198: }
1199:
1200: strm.avail_in = s->cluster_size;
1201: strm.next_in = (uint8_t *)buf;
1202: strm.avail_out = s->cluster_size;
1203: strm.next_out = out_buf;
1204:
1205: ret = deflate(&strm, Z_FINISH);
1206: if (ret != Z_STREAM_END && ret != Z_OK) {
1207: qemu_free(out_buf);
1208: deflateEnd(&strm);
1209: return -1;
1210: }
1211: out_len = strm.next_out - out_buf;
1212:
1213: deflateEnd(&strm);
1214:
1215: if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
1216: /* could not compress: write normal cluster */
1217: bdrv_write(bs, sector_num, buf, s->cluster_sectors);
1218: } else {
1219: cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
1220: sector_num << 9, out_len);
1221: if (!cluster_offset)
1222: return -1;
1223: cluster_offset &= s->cluster_offset_mask;
1.1.1.6 root 1224: BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
1225: if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
1.1 root 1226: qemu_free(out_buf);
1227: return -1;
1228: }
1229: }
1230:
1231: qemu_free(out_buf);
1232: return 0;
1233: }
1234:
1.1.1.7 root 1235: static int qcow2_flush(BlockDriverState *bs)
1.1 root 1236: {
1.1.1.7 root 1237: BDRVQcowState *s = bs->opaque;
1238: int ret;
1239:
1240: ret = qcow2_cache_flush(bs, s->l2_table_cache);
1241: if (ret < 0) {
1242: return ret;
1243: }
1244:
1245: ret = qcow2_cache_flush(bs, s->refcount_block_cache);
1246: if (ret < 0) {
1247: return ret;
1248: }
1249:
1250: return bdrv_flush(bs->file);
1.1.1.6 root 1251: }
1252:
1.1.1.7 root 1253: static BlockDriverAIOCB *qcow2_aio_flush(BlockDriverState *bs,
1254: BlockDriverCompletionFunc *cb,
1255: void *opaque)
1.1.1.6 root 1256: {
1.1.1.7 root 1257: BDRVQcowState *s = bs->opaque;
1258: int ret;
1259:
1260: ret = qcow2_cache_flush(bs, s->l2_table_cache);
1261: if (ret < 0) {
1262: return NULL;
1263: }
1264:
1265: ret = qcow2_cache_flush(bs, s->refcount_block_cache);
1266: if (ret < 0) {
1267: return NULL;
1268: }
1269:
1.1.1.6 root 1270: return bdrv_aio_flush(bs->file, cb, opaque);
1.1 root 1271: }
1272:
1.1.1.7 root 1273: static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
1.1 root 1274: {
1275: return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
1276: }
1277:
1.1.1.7 root 1278: static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1.1 root 1279: {
1280: BDRVQcowState *s = bs->opaque;
1281: bdi->cluster_size = s->cluster_size;
1.1.1.7 root 1282: bdi->vm_state_offset = qcow2_vm_state_offset(s);
1.1 root 1283: return 0;
1284: }
1285:
1286:
1.1.1.7 root 1287: static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result)
1.1 root 1288: {
1.1.1.6 root 1289: return qcow2_check_refcounts(bs, result);
1.1 root 1290: }
1291:
1292: #if 0
1293: static void dump_refcounts(BlockDriverState *bs)
1294: {
1295: BDRVQcowState *s = bs->opaque;
1296: int64_t nb_clusters, k, k1, size;
1297: int refcount;
1298:
1.1.1.6 root 1299: size = bdrv_getlength(bs->file);
1.1 root 1300: nb_clusters = size_to_clusters(s, size);
1301: for(k = 0; k < nb_clusters;) {
1302: k1 = k;
1303: refcount = get_refcount(bs, k);
1304: k++;
1305: while (k < nb_clusters && get_refcount(bs, k) == refcount)
1306: k++;
1.1.1.6 root 1307: printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
1308: k - k1);
1.1 root 1309: }
1310: }
1311: #endif
1312:
1.1.1.7 root 1313: static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1314: int64_t pos, int size)
1.1 root 1315: {
1316: BDRVQcowState *s = bs->opaque;
1317: int growable = bs->growable;
1.1.1.3 root 1318: int ret;
1.1 root 1319:
1.1.1.6 root 1320: BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
1.1 root 1321: bs->growable = 1;
1.1.1.7 root 1322: ret = bdrv_pwrite(bs, qcow2_vm_state_offset(s) + pos, buf, size);
1.1 root 1323: bs->growable = growable;
1324:
1.1.1.3 root 1325: return ret;
1.1 root 1326: }
1327:
1.1.1.7 root 1328: static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1329: int64_t pos, int size)
1.1 root 1330: {
1331: BDRVQcowState *s = bs->opaque;
1332: int growable = bs->growable;
1333: int ret;
1334:
1.1.1.6 root 1335: BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
1.1 root 1336: bs->growable = 1;
1.1.1.7 root 1337: ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size);
1.1 root 1338: bs->growable = growable;
1339:
1340: return ret;
1341: }
1342:
1.1.1.7 root 1343: static QEMUOptionParameter qcow2_create_options[] = {
1.1 root 1344: {
1345: .name = BLOCK_OPT_SIZE,
1346: .type = OPT_SIZE,
1347: .help = "Virtual disk size"
1348: },
1349: {
1350: .name = BLOCK_OPT_BACKING_FILE,
1351: .type = OPT_STRING,
1352: .help = "File name of a base image"
1353: },
1354: {
1355: .name = BLOCK_OPT_BACKING_FMT,
1356: .type = OPT_STRING,
1357: .help = "Image format of the base image"
1358: },
1359: {
1360: .name = BLOCK_OPT_ENCRYPT,
1361: .type = OPT_FLAG,
1362: .help = "Encrypt the image"
1363: },
1364: {
1365: .name = BLOCK_OPT_CLUSTER_SIZE,
1366: .type = OPT_SIZE,
1.1.1.8 ! root 1367: .help = "qcow2 cluster size",
! 1368: .value = { .n = DEFAULT_CLUSTER_SIZE },
1.1 root 1369: },
1.1.1.2 root 1370: {
1371: .name = BLOCK_OPT_PREALLOC,
1372: .type = OPT_STRING,
1373: .help = "Preallocation mode (allowed values: off, metadata)"
1374: },
1.1 root 1375: { NULL }
1376: };
1377:
1378: static BlockDriver bdrv_qcow2 = {
1.1.1.7 root 1379: .format_name = "qcow2",
1380: .instance_size = sizeof(BDRVQcowState),
1381: .bdrv_probe = qcow2_probe,
1382: .bdrv_open = qcow2_open,
1383: .bdrv_close = qcow2_close,
1384: .bdrv_create = qcow2_create,
1385: .bdrv_flush = qcow2_flush,
1386: .bdrv_is_allocated = qcow2_is_allocated,
1387: .bdrv_set_key = qcow2_set_key,
1388: .bdrv_make_empty = qcow2_make_empty,
1389:
1390: .bdrv_aio_readv = qcow2_aio_readv,
1391: .bdrv_aio_writev = qcow2_aio_writev,
1392: .bdrv_aio_flush = qcow2_aio_flush,
1.1.1.6 root 1393:
1.1.1.7 root 1394: .bdrv_discard = qcow2_discard,
1.1.1.6 root 1395: .bdrv_truncate = qcow2_truncate,
1.1.1.7 root 1396: .bdrv_write_compressed = qcow2_write_compressed,
1.1 root 1397:
1398: .bdrv_snapshot_create = qcow2_snapshot_create,
1399: .bdrv_snapshot_goto = qcow2_snapshot_goto,
1400: .bdrv_snapshot_delete = qcow2_snapshot_delete,
1401: .bdrv_snapshot_list = qcow2_snapshot_list,
1.1.1.7 root 1402: .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
1403: .bdrv_get_info = qcow2_get_info,
1.1 root 1404:
1.1.1.7 root 1405: .bdrv_save_vmstate = qcow2_save_vmstate,
1406: .bdrv_load_vmstate = qcow2_load_vmstate,
1.1 root 1407:
1.1.1.6 root 1408: .bdrv_change_backing_file = qcow2_change_backing_file,
1409:
1.1.1.7 root 1410: .create_options = qcow2_create_options,
1411: .bdrv_check = qcow2_check,
1.1 root 1412: };
1413:
1414: static void bdrv_qcow2_init(void)
1415: {
1416: bdrv_register(&bdrv_qcow2);
1417: }
1418:
1419: block_init(bdrv_qcow2_init);
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