xref: /qemu/block/qcow2.c (revision 06d9260ffa9dfa0e96e015501e43480ab66f96f6)
1585f8587Sbellard /*
2585f8587Sbellard  * Block driver for the QCOW version 2 format
3585f8587Sbellard  *
4585f8587Sbellard  * Copyright (c) 2004-2006 Fabrice Bellard
5585f8587Sbellard  *
6585f8587Sbellard  * Permission is hereby granted, free of charge, to any person obtaining a copy
7585f8587Sbellard  * of this software and associated documentation files (the "Software"), to deal
8585f8587Sbellard  * in the Software without restriction, including without limitation the rights
9585f8587Sbellard  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10585f8587Sbellard  * copies of the Software, and to permit persons to whom the Software is
11585f8587Sbellard  * furnished to do so, subject to the following conditions:
12585f8587Sbellard  *
13585f8587Sbellard  * The above copyright notice and this permission notice shall be included in
14585f8587Sbellard  * all copies or substantial portions of the Software.
15585f8587Sbellard  *
16585f8587Sbellard  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17585f8587Sbellard  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18585f8587Sbellard  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19585f8587Sbellard  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20585f8587Sbellard  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21585f8587Sbellard  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22585f8587Sbellard  * THE SOFTWARE.
23585f8587Sbellard  */
24faf07963Spbrook #include "qemu-common.h"
25585f8587Sbellard #include "block_int.h"
265efa9d5aSAnthony Liguori #include "module.h"
27585f8587Sbellard #include <zlib.h>
28585f8587Sbellard #include "aes.h"
29f7d0fe02SKevin Wolf #include "block/qcow2.h"
30a9420734SKevin Wolf #include "qemu-error.h"
31e8cdcec1SKevin Wolf #include "qerror.h"
32585f8587Sbellard 
33585f8587Sbellard /*
34585f8587Sbellard   Differences with QCOW:
35585f8587Sbellard 
36585f8587Sbellard   - Support for multiple incremental snapshots.
37585f8587Sbellard   - Memory management by reference counts.
38585f8587Sbellard   - Clusters which have a reference count of one have the bit
39585f8587Sbellard     QCOW_OFLAG_COPIED to optimize write performance.
40585f8587Sbellard   - Size of compressed clusters is stored in sectors to reduce bit usage
41585f8587Sbellard     in the cluster offsets.
42585f8587Sbellard   - Support for storing additional data (such as the VM state) in the
43585f8587Sbellard     snapshots.
44585f8587Sbellard   - If a backing store is used, the cluster size is not constrained
45585f8587Sbellard     (could be backported to QCOW).
46585f8587Sbellard   - L2 tables have always a size of one cluster.
47585f8587Sbellard */
48585f8587Sbellard 
499b80ddf3Saliguori 
509b80ddf3Saliguori typedef struct {
519b80ddf3Saliguori     uint32_t magic;
529b80ddf3Saliguori     uint32_t len;
539b80ddf3Saliguori } QCowExtension;
547c80ab3fSJes Sorensen #define  QCOW2_EXT_MAGIC_END 0
557c80ab3fSJes Sorensen #define  QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
569b80ddf3Saliguori 
577c80ab3fSJes Sorensen static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
58585f8587Sbellard {
59585f8587Sbellard     const QCowHeader *cow_header = (const void *)buf;
60585f8587Sbellard 
61585f8587Sbellard     if (buf_size >= sizeof(QCowHeader) &&
62585f8587Sbellard         be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
63e8cdcec1SKevin Wolf         be32_to_cpu(cow_header->version) >= QCOW_VERSION)
64585f8587Sbellard         return 100;
65585f8587Sbellard     else
66585f8587Sbellard         return 0;
67585f8587Sbellard }
68585f8587Sbellard 
699b80ddf3Saliguori 
709b80ddf3Saliguori /*
719b80ddf3Saliguori  * read qcow2 extension and fill bs
729b80ddf3Saliguori  * start reading from start_offset
739b80ddf3Saliguori  * finish reading upon magic of value 0 or when end_offset reached
749b80ddf3Saliguori  * unknown magic is skipped (future extension this version knows nothing about)
759b80ddf3Saliguori  * return 0 upon success, non-0 otherwise
769b80ddf3Saliguori  */
777c80ab3fSJes Sorensen static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
789b80ddf3Saliguori                                  uint64_t end_offset)
799b80ddf3Saliguori {
809b80ddf3Saliguori     QCowExtension ext;
819b80ddf3Saliguori     uint64_t offset;
829b80ddf3Saliguori 
839b80ddf3Saliguori #ifdef DEBUG_EXT
847c80ab3fSJes Sorensen     printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
859b80ddf3Saliguori #endif
869b80ddf3Saliguori     offset = start_offset;
879b80ddf3Saliguori     while (offset < end_offset) {
889b80ddf3Saliguori 
899b80ddf3Saliguori #ifdef DEBUG_EXT
906cbc3031SPhilipp Hahn         BDRVQcowState *s = bs->opaque;
919b80ddf3Saliguori         /* Sanity check */
929b80ddf3Saliguori         if (offset > s->cluster_size)
937c80ab3fSJes Sorensen             printf("qcow2_read_extension: suspicious offset %lu\n", offset);
949b80ddf3Saliguori 
959b80ddf3Saliguori         printf("attemting to read extended header in offset %lu\n", offset);
969b80ddf3Saliguori #endif
979b80ddf3Saliguori 
9866f82ceeSKevin Wolf         if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
997c80ab3fSJes Sorensen             fprintf(stderr, "qcow2_read_extension: ERROR: "
1000bfcd599SBlue Swirl                     "pread fail from offset %" PRIu64 "\n",
1010bfcd599SBlue Swirl                     offset);
1029b80ddf3Saliguori             return 1;
1039b80ddf3Saliguori         }
1049b80ddf3Saliguori         be32_to_cpus(&ext.magic);
1059b80ddf3Saliguori         be32_to_cpus(&ext.len);
1069b80ddf3Saliguori         offset += sizeof(ext);
1079b80ddf3Saliguori #ifdef DEBUG_EXT
1089b80ddf3Saliguori         printf("ext.magic = 0x%x\n", ext.magic);
1099b80ddf3Saliguori #endif
1109b80ddf3Saliguori         switch (ext.magic) {
1117c80ab3fSJes Sorensen         case QCOW2_EXT_MAGIC_END:
1129b80ddf3Saliguori             return 0;
113f965509cSaliguori 
1147c80ab3fSJes Sorensen         case QCOW2_EXT_MAGIC_BACKING_FORMAT:
115f965509cSaliguori             if (ext.len >= sizeof(bs->backing_format)) {
116f965509cSaliguori                 fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
1174c978075Saliguori                         " (>=%zu)\n",
118f965509cSaliguori                         ext.len, sizeof(bs->backing_format));
119f965509cSaliguori                 return 2;
120f965509cSaliguori             }
12166f82ceeSKevin Wolf             if (bdrv_pread(bs->file, offset , bs->backing_format,
122f965509cSaliguori                            ext.len) != ext.len)
123f965509cSaliguori                 return 3;
124f965509cSaliguori             bs->backing_format[ext.len] = '\0';
125f965509cSaliguori #ifdef DEBUG_EXT
126f965509cSaliguori             printf("Qcow2: Got format extension %s\n", bs->backing_format);
127f965509cSaliguori #endif
128e1c7f0e3SKevin Wolf             offset = ((offset + ext.len + 7) & ~7);
129f965509cSaliguori             break;
130f965509cSaliguori 
1319b80ddf3Saliguori         default:
1329b80ddf3Saliguori             /* unknown magic -- just skip it */
133e1c7f0e3SKevin Wolf             offset = ((offset + ext.len + 7) & ~7);
1349b80ddf3Saliguori             break;
1359b80ddf3Saliguori         }
1369b80ddf3Saliguori     }
1379b80ddf3Saliguori 
1389b80ddf3Saliguori     return 0;
1399b80ddf3Saliguori }
1409b80ddf3Saliguori 
1419b80ddf3Saliguori 
1427c80ab3fSJes Sorensen static int qcow2_open(BlockDriverState *bs, int flags)
143585f8587Sbellard {
144585f8587Sbellard     BDRVQcowState *s = bs->opaque;
1456d85a57eSJes Sorensen     int len, i, ret = 0;
146585f8587Sbellard     QCowHeader header;
1479b80ddf3Saliguori     uint64_t ext_end;
14829c1a730SKevin Wolf     bool writethrough;
149585f8587Sbellard 
1506d85a57eSJes Sorensen     ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
1516d85a57eSJes Sorensen     if (ret < 0) {
152585f8587Sbellard         goto fail;
1536d85a57eSJes Sorensen     }
154585f8587Sbellard     be32_to_cpus(&header.magic);
155585f8587Sbellard     be32_to_cpus(&header.version);
156585f8587Sbellard     be64_to_cpus(&header.backing_file_offset);
157585f8587Sbellard     be32_to_cpus(&header.backing_file_size);
158585f8587Sbellard     be64_to_cpus(&header.size);
159585f8587Sbellard     be32_to_cpus(&header.cluster_bits);
160585f8587Sbellard     be32_to_cpus(&header.crypt_method);
161585f8587Sbellard     be64_to_cpus(&header.l1_table_offset);
162585f8587Sbellard     be32_to_cpus(&header.l1_size);
163585f8587Sbellard     be64_to_cpus(&header.refcount_table_offset);
164585f8587Sbellard     be32_to_cpus(&header.refcount_table_clusters);
165585f8587Sbellard     be64_to_cpus(&header.snapshots_offset);
166585f8587Sbellard     be32_to_cpus(&header.nb_snapshots);
167585f8587Sbellard 
168e8cdcec1SKevin Wolf     if (header.magic != QCOW_MAGIC) {
1696d85a57eSJes Sorensen         ret = -EINVAL;
170585f8587Sbellard         goto fail;
1716d85a57eSJes Sorensen     }
172e8cdcec1SKevin Wolf     if (header.version != QCOW_VERSION) {
173e8cdcec1SKevin Wolf         char version[64];
174e8cdcec1SKevin Wolf         snprintf(version, sizeof(version), "QCOW version %d", header.version);
175e8cdcec1SKevin Wolf         qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
176e8cdcec1SKevin Wolf             bs->device_name, "qcow2", version);
177e8cdcec1SKevin Wolf         ret = -ENOTSUP;
178e8cdcec1SKevin Wolf         goto fail;
179e8cdcec1SKevin Wolf     }
180d191d12dSStefan Weil     if (header.cluster_bits < MIN_CLUSTER_BITS ||
1816d85a57eSJes Sorensen         header.cluster_bits > MAX_CLUSTER_BITS) {
1826d85a57eSJes Sorensen         ret = -EINVAL;
183585f8587Sbellard         goto fail;
1846d85a57eSJes Sorensen     }
1856d85a57eSJes Sorensen     if (header.crypt_method > QCOW_CRYPT_AES) {
1866d85a57eSJes Sorensen         ret = -EINVAL;
187585f8587Sbellard         goto fail;
1886d85a57eSJes Sorensen     }
189585f8587Sbellard     s->crypt_method_header = header.crypt_method;
1906d85a57eSJes Sorensen     if (s->crypt_method_header) {
191585f8587Sbellard         bs->encrypted = 1;
1926d85a57eSJes Sorensen     }
193585f8587Sbellard     s->cluster_bits = header.cluster_bits;
194585f8587Sbellard     s->cluster_size = 1 << s->cluster_bits;
195585f8587Sbellard     s->cluster_sectors = 1 << (s->cluster_bits - 9);
196585f8587Sbellard     s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
197585f8587Sbellard     s->l2_size = 1 << s->l2_bits;
198585f8587Sbellard     bs->total_sectors = header.size / 512;
199585f8587Sbellard     s->csize_shift = (62 - (s->cluster_bits - 8));
200585f8587Sbellard     s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
201585f8587Sbellard     s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
202585f8587Sbellard     s->refcount_table_offset = header.refcount_table_offset;
203585f8587Sbellard     s->refcount_table_size =
204585f8587Sbellard         header.refcount_table_clusters << (s->cluster_bits - 3);
205585f8587Sbellard 
206585f8587Sbellard     s->snapshots_offset = header.snapshots_offset;
207585f8587Sbellard     s->nb_snapshots = header.nb_snapshots;
208585f8587Sbellard 
209585f8587Sbellard     /* read the level 1 table */
210585f8587Sbellard     s->l1_size = header.l1_size;
211419b19d9SStefan Hajnoczi     s->l1_vm_state_index = size_to_l1(s, header.size);
212585f8587Sbellard     /* the L1 table must contain at least enough entries to put
213585f8587Sbellard        header.size bytes */
2146d85a57eSJes Sorensen     if (s->l1_size < s->l1_vm_state_index) {
2156d85a57eSJes Sorensen         ret = -EINVAL;
216585f8587Sbellard         goto fail;
2176d85a57eSJes Sorensen     }
218585f8587Sbellard     s->l1_table_offset = header.l1_table_offset;
219d191d12dSStefan Weil     if (s->l1_size > 0) {
2207267c094SAnthony Liguori         s->l1_table = g_malloc0(
2213f6a3ee5SKevin Wolf             align_offset(s->l1_size * sizeof(uint64_t), 512));
2226d85a57eSJes Sorensen         ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
2236d85a57eSJes Sorensen                          s->l1_size * sizeof(uint64_t));
2246d85a57eSJes Sorensen         if (ret < 0) {
225585f8587Sbellard             goto fail;
2266d85a57eSJes Sorensen         }
227585f8587Sbellard         for(i = 0;i < s->l1_size; i++) {
228585f8587Sbellard             be64_to_cpus(&s->l1_table[i]);
229585f8587Sbellard         }
230d191d12dSStefan Weil     }
23129c1a730SKevin Wolf 
23229c1a730SKevin Wolf     /* alloc L2 table/refcount block cache */
233a6599793SChristoph Hellwig     writethrough = ((flags & BDRV_O_CACHE_WB) == 0);
23429c1a730SKevin Wolf     s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, writethrough);
23529c1a730SKevin Wolf     s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE,
23629c1a730SKevin Wolf         writethrough);
23729c1a730SKevin Wolf 
2387267c094SAnthony Liguori     s->cluster_cache = g_malloc(s->cluster_size);
239585f8587Sbellard     /* one more sector for decompressed data alignment */
240dea43a65SFrediano Ziglio     s->cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
241095a9c58Saliguori                                   + 512);
242585f8587Sbellard     s->cluster_cache_offset = -1;
243*06d9260fSAnthony Liguori     s->flags = flags;
244585f8587Sbellard 
2456d85a57eSJes Sorensen     ret = qcow2_refcount_init(bs);
2466d85a57eSJes Sorensen     if (ret != 0) {
247585f8587Sbellard         goto fail;
2486d85a57eSJes Sorensen     }
249585f8587Sbellard 
25072cf2d4fSBlue Swirl     QLIST_INIT(&s->cluster_allocs);
251f214978aSKevin Wolf 
2529b80ddf3Saliguori     /* read qcow2 extensions */
2536d85a57eSJes Sorensen     if (header.backing_file_offset) {
2549b80ddf3Saliguori         ext_end = header.backing_file_offset;
2556d85a57eSJes Sorensen     } else {
2569b80ddf3Saliguori         ext_end = s->cluster_size;
2576d85a57eSJes Sorensen     }
2586d85a57eSJes Sorensen     if (qcow2_read_extensions(bs, sizeof(header), ext_end)) {
2596d85a57eSJes Sorensen         ret = -EINVAL;
2609b80ddf3Saliguori         goto fail;
2616d85a57eSJes Sorensen     }
2629b80ddf3Saliguori 
263585f8587Sbellard     /* read the backing file name */
264585f8587Sbellard     if (header.backing_file_offset != 0) {
265585f8587Sbellard         len = header.backing_file_size;
2666d85a57eSJes Sorensen         if (len > 1023) {
267585f8587Sbellard             len = 1023;
2686d85a57eSJes Sorensen         }
2696d85a57eSJes Sorensen         ret = bdrv_pread(bs->file, header.backing_file_offset,
2706d85a57eSJes Sorensen                          bs->backing_file, len);
2716d85a57eSJes Sorensen         if (ret < 0) {
272585f8587Sbellard             goto fail;
2736d85a57eSJes Sorensen         }
274585f8587Sbellard         bs->backing_file[len] = '\0';
275585f8587Sbellard     }
2766d85a57eSJes Sorensen     if (qcow2_read_snapshots(bs) < 0) {
2776d85a57eSJes Sorensen         ret = -EINVAL;
278585f8587Sbellard         goto fail;
2796d85a57eSJes Sorensen     }
280585f8587Sbellard 
28168d100e9SKevin Wolf     /* Initialise locks */
28268d100e9SKevin Wolf     qemu_co_mutex_init(&s->lock);
28368d100e9SKevin Wolf 
284585f8587Sbellard #ifdef DEBUG_ALLOC
2856cbc3031SPhilipp Hahn     {
2866cbc3031SPhilipp Hahn         BdrvCheckResult result = {0};
2876cbc3031SPhilipp Hahn         qcow2_check_refcounts(bs, &result);
2886cbc3031SPhilipp Hahn     }
289585f8587Sbellard #endif
2906d85a57eSJes Sorensen     return ret;
291585f8587Sbellard 
292585f8587Sbellard  fail:
293ed6ccf0fSKevin Wolf     qcow2_free_snapshots(bs);
294ed6ccf0fSKevin Wolf     qcow2_refcount_close(bs);
2957267c094SAnthony Liguori     g_free(s->l1_table);
29629c1a730SKevin Wolf     if (s->l2_table_cache) {
29729c1a730SKevin Wolf         qcow2_cache_destroy(bs, s->l2_table_cache);
29829c1a730SKevin Wolf     }
2997267c094SAnthony Liguori     g_free(s->cluster_cache);
300dea43a65SFrediano Ziglio     qemu_vfree(s->cluster_data);
3016d85a57eSJes Sorensen     return ret;
302585f8587Sbellard }
303585f8587Sbellard 
3047c80ab3fSJes Sorensen static int qcow2_set_key(BlockDriverState *bs, const char *key)
305585f8587Sbellard {
306585f8587Sbellard     BDRVQcowState *s = bs->opaque;
307585f8587Sbellard     uint8_t keybuf[16];
308585f8587Sbellard     int len, i;
309585f8587Sbellard 
310585f8587Sbellard     memset(keybuf, 0, 16);
311585f8587Sbellard     len = strlen(key);
312585f8587Sbellard     if (len > 16)
313585f8587Sbellard         len = 16;
314585f8587Sbellard     /* XXX: we could compress the chars to 7 bits to increase
315585f8587Sbellard        entropy */
316585f8587Sbellard     for(i = 0;i < len;i++) {
317585f8587Sbellard         keybuf[i] = key[i];
318585f8587Sbellard     }
319585f8587Sbellard     s->crypt_method = s->crypt_method_header;
320585f8587Sbellard 
321585f8587Sbellard     if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
322585f8587Sbellard         return -1;
323585f8587Sbellard     if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
324585f8587Sbellard         return -1;
325585f8587Sbellard #if 0
326585f8587Sbellard     /* test */
327585f8587Sbellard     {
328585f8587Sbellard         uint8_t in[16];
329585f8587Sbellard         uint8_t out[16];
330585f8587Sbellard         uint8_t tmp[16];
331585f8587Sbellard         for(i=0;i<16;i++)
332585f8587Sbellard             in[i] = i;
333585f8587Sbellard         AES_encrypt(in, tmp, &s->aes_encrypt_key);
334585f8587Sbellard         AES_decrypt(tmp, out, &s->aes_decrypt_key);
335585f8587Sbellard         for(i = 0; i < 16; i++)
336585f8587Sbellard             printf(" %02x", tmp[i]);
337585f8587Sbellard         printf("\n");
338585f8587Sbellard         for(i = 0; i < 16; i++)
339585f8587Sbellard             printf(" %02x", out[i]);
340585f8587Sbellard         printf("\n");
341585f8587Sbellard     }
342585f8587Sbellard #endif
343585f8587Sbellard     return 0;
344585f8587Sbellard }
345585f8587Sbellard 
3467c80ab3fSJes Sorensen static int qcow2_is_allocated(BlockDriverState *bs, int64_t sector_num,
347585f8587Sbellard                               int nb_sectors, int *pnum)
348585f8587Sbellard {
349585f8587Sbellard     uint64_t cluster_offset;
3501c46efaaSKevin Wolf     int ret;
351585f8587Sbellard 
352095a9c58Saliguori     *pnum = nb_sectors;
3531c46efaaSKevin Wolf     /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
3541c46efaaSKevin Wolf      * pass them on today */
3551c46efaaSKevin Wolf     ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
3561c46efaaSKevin Wolf     if (ret < 0) {
3571c46efaaSKevin Wolf         *pnum = 0;
3581c46efaaSKevin Wolf     }
359095a9c58Saliguori 
360585f8587Sbellard     return (cluster_offset != 0);
361585f8587Sbellard }
362585f8587Sbellard 
363a9465922Sbellard /* handle reading after the end of the backing file */
364bd28f835SKevin Wolf int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
365bd28f835SKevin Wolf                   int64_t sector_num, int nb_sectors)
366a9465922Sbellard {
367a9465922Sbellard     int n1;
368a9465922Sbellard     if ((sector_num + nb_sectors) <= bs->total_sectors)
369a9465922Sbellard         return nb_sectors;
370a9465922Sbellard     if (sector_num >= bs->total_sectors)
371a9465922Sbellard         n1 = 0;
372a9465922Sbellard     else
373a9465922Sbellard         n1 = bs->total_sectors - sector_num;
374bd28f835SKevin Wolf 
375e0d9c6f9SChunqiang Tang     qemu_iovec_memset_skip(qiov, 0, 512 * (nb_sectors - n1), 512 * n1);
376bd28f835SKevin Wolf 
377a9465922Sbellard     return n1;
378a9465922Sbellard }
379a9465922Sbellard 
3803fc48d09SFrediano Ziglio static int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
3813fc48d09SFrediano Ziglio                           int remaining_sectors, QEMUIOVector *qiov)
3821490791fSaliguori {
383585f8587Sbellard     BDRVQcowState *s = bs->opaque;
384a9465922Sbellard     int index_in_cluster, n1;
38568d100e9SKevin Wolf     int ret;
386faf575c1SFrediano Ziglio     int cur_nr_sectors; /* number of sectors in current iteration */
387c2bdd990SFrediano Ziglio     uint64_t cluster_offset = 0;
3883fc48d09SFrediano Ziglio     uint64_t bytes_done = 0;
3893fc48d09SFrediano Ziglio     QEMUIOVector hd_qiov;
3903fc48d09SFrediano Ziglio     uint8_t *cluster_data = NULL;
391585f8587Sbellard 
3923fc48d09SFrediano Ziglio     qemu_iovec_init(&hd_qiov, qiov->niov);
3933fc48d09SFrediano Ziglio 
3943fc48d09SFrediano Ziglio     qemu_co_mutex_lock(&s->lock);
3953fc48d09SFrediano Ziglio 
3963fc48d09SFrediano Ziglio     while (remaining_sectors != 0) {
397585f8587Sbellard 
398faf575c1SFrediano Ziglio         /* prepare next request */
3993fc48d09SFrediano Ziglio         cur_nr_sectors = remaining_sectors;
400bd28f835SKevin Wolf         if (s->crypt_method) {
401faf575c1SFrediano Ziglio             cur_nr_sectors = MIN(cur_nr_sectors,
402bd28f835SKevin Wolf                 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
403bd28f835SKevin Wolf         }
404bd28f835SKevin Wolf 
4053fc48d09SFrediano Ziglio         ret = qcow2_get_cluster_offset(bs, sector_num << 9,
406c2bdd990SFrediano Ziglio             &cur_nr_sectors, &cluster_offset);
4071c46efaaSKevin Wolf         if (ret < 0) {
4083fc48d09SFrediano Ziglio             goto fail;
4091c46efaaSKevin Wolf         }
4101c46efaaSKevin Wolf 
4113fc48d09SFrediano Ziglio         index_in_cluster = sector_num & (s->cluster_sectors - 1);
412585f8587Sbellard 
4133fc48d09SFrediano Ziglio         qemu_iovec_reset(&hd_qiov);
4143fc48d09SFrediano Ziglio         qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
415faf575c1SFrediano Ziglio             cur_nr_sectors * 512);
416bd28f835SKevin Wolf 
417c2bdd990SFrediano Ziglio         if (!cluster_offset) {
418bd28f835SKevin Wolf 
419585f8587Sbellard             if (bs->backing_hd) {
420585f8587Sbellard                 /* read from the base image */
4213fc48d09SFrediano Ziglio                 n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov,
4223fc48d09SFrediano Ziglio                     sector_num, cur_nr_sectors);
423a9465922Sbellard                 if (n1 > 0) {
42466f82ceeSKevin Wolf                     BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
42568d100e9SKevin Wolf                     qemu_co_mutex_unlock(&s->lock);
4263fc48d09SFrediano Ziglio                     ret = bdrv_co_readv(bs->backing_hd, sector_num,
4273fc48d09SFrediano Ziglio                                         n1, &hd_qiov);
42868d100e9SKevin Wolf                     qemu_co_mutex_lock(&s->lock);
42968d100e9SKevin Wolf                     if (ret < 0) {
4303fc48d09SFrediano Ziglio                         goto fail;
4313ab4c7e9SKevin Wolf                     }
4321490791fSaliguori                 }
433a9465922Sbellard             } else {
434585f8587Sbellard                 /* Note: in this case, no need to wait */
4353fc48d09SFrediano Ziglio                 qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors);
4361490791fSaliguori             }
437c2bdd990SFrediano Ziglio         } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
438585f8587Sbellard             /* add AIO support for compressed blocks ? */
439c2bdd990SFrediano Ziglio             ret = qcow2_decompress_cluster(bs, cluster_offset);
4408af36488SKevin Wolf             if (ret < 0) {
4413fc48d09SFrediano Ziglio                 goto fail;
4428af36488SKevin Wolf             }
443bd28f835SKevin Wolf 
4443fc48d09SFrediano Ziglio             qemu_iovec_from_buffer(&hd_qiov,
445bd28f835SKevin Wolf                 s->cluster_cache + index_in_cluster * 512,
446faf575c1SFrediano Ziglio                 512 * cur_nr_sectors);
447585f8587Sbellard         } else {
448c2bdd990SFrediano Ziglio             if ((cluster_offset & 511) != 0) {
4493fc48d09SFrediano Ziglio                 ret = -EIO;
4503fc48d09SFrediano Ziglio                 goto fail;
451585f8587Sbellard             }
452c87c0672Saliguori 
453bd28f835SKevin Wolf             if (s->crypt_method) {
454bd28f835SKevin Wolf                 /*
455bd28f835SKevin Wolf                  * For encrypted images, read everything into a temporary
456bd28f835SKevin Wolf                  * contiguous buffer on which the AES functions can work.
457bd28f835SKevin Wolf                  */
4583fc48d09SFrediano Ziglio                 if (!cluster_data) {
4593fc48d09SFrediano Ziglio                     cluster_data =
460dea43a65SFrediano Ziglio                         qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
461bd28f835SKevin Wolf                 }
462bd28f835SKevin Wolf 
463faf575c1SFrediano Ziglio                 assert(cur_nr_sectors <=
464bd28f835SKevin Wolf                     QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors);
4653fc48d09SFrediano Ziglio                 qemu_iovec_reset(&hd_qiov);
4663fc48d09SFrediano Ziglio                 qemu_iovec_add(&hd_qiov, cluster_data,
467faf575c1SFrediano Ziglio                     512 * cur_nr_sectors);
468bd28f835SKevin Wolf             }
469bd28f835SKevin Wolf 
47066f82ceeSKevin Wolf             BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
47168d100e9SKevin Wolf             qemu_co_mutex_unlock(&s->lock);
47268d100e9SKevin Wolf             ret = bdrv_co_readv(bs->file,
473c2bdd990SFrediano Ziglio                                 (cluster_offset >> 9) + index_in_cluster,
4743fc48d09SFrediano Ziglio                                 cur_nr_sectors, &hd_qiov);
47568d100e9SKevin Wolf             qemu_co_mutex_lock(&s->lock);
47668d100e9SKevin Wolf             if (ret < 0) {
4773fc48d09SFrediano Ziglio                 goto fail;
478585f8587Sbellard             }
479faf575c1SFrediano Ziglio             if (s->crypt_method) {
4803fc48d09SFrediano Ziglio                 qcow2_encrypt_sectors(s, sector_num,  cluster_data,
4813fc48d09SFrediano Ziglio                     cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
4823fc48d09SFrediano Ziglio                 qemu_iovec_reset(&hd_qiov);
4833fc48d09SFrediano Ziglio                 qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
484faf575c1SFrediano Ziglio                     cur_nr_sectors * 512);
4853fc48d09SFrediano Ziglio                 qemu_iovec_from_buffer(&hd_qiov, cluster_data,
486faf575c1SFrediano Ziglio                     512 * cur_nr_sectors);
487171e3d6bSKevin Wolf             }
488faf575c1SFrediano Ziglio         }
489faf575c1SFrediano Ziglio 
4903fc48d09SFrediano Ziglio         remaining_sectors -= cur_nr_sectors;
4913fc48d09SFrediano Ziglio         sector_num += cur_nr_sectors;
4923fc48d09SFrediano Ziglio         bytes_done += cur_nr_sectors * 512;
4935ebaa27eSFrediano Ziglio     }
4943fc48d09SFrediano Ziglio     ret = 0;
495f141eafeSaliguori 
4963fc48d09SFrediano Ziglio fail:
49768d100e9SKevin Wolf     qemu_co_mutex_unlock(&s->lock);
49868d100e9SKevin Wolf 
4993fc48d09SFrediano Ziglio     qemu_iovec_destroy(&hd_qiov);
500dea43a65SFrediano Ziglio     qemu_vfree(cluster_data);
50168d100e9SKevin Wolf 
50268d100e9SKevin Wolf     return ret;
503585f8587Sbellard }
504585f8587Sbellard 
50568d100e9SKevin Wolf static void run_dependent_requests(BDRVQcowState *s, QCowL2Meta *m)
506f214978aSKevin Wolf {
507f214978aSKevin Wolf     /* Take the request off the list of running requests */
508f214978aSKevin Wolf     if (m->nb_clusters != 0) {
50972cf2d4fSBlue Swirl         QLIST_REMOVE(m, next_in_flight);
510f214978aSKevin Wolf     }
511f214978aSKevin Wolf 
512d4c146f0SStefan Hajnoczi     /* Restart all dependent requests */
51368d100e9SKevin Wolf     if (!qemu_co_queue_empty(&m->dependent_requests)) {
51468d100e9SKevin Wolf         qemu_co_mutex_unlock(&s->lock);
51568d100e9SKevin Wolf         while(qemu_co_queue_next(&m->dependent_requests));
51668d100e9SKevin Wolf         qemu_co_mutex_lock(&s->lock);
51768d100e9SKevin Wolf     }
518f214978aSKevin Wolf }
519f214978aSKevin Wolf 
5203fc48d09SFrediano Ziglio static int qcow2_co_writev(BlockDriverState *bs,
5213fc48d09SFrediano Ziglio                            int64_t sector_num,
5223fc48d09SFrediano Ziglio                            int remaining_sectors,
5233fc48d09SFrediano Ziglio                            QEMUIOVector *qiov)
524585f8587Sbellard {
525585f8587Sbellard     BDRVQcowState *s = bs->opaque;
526585f8587Sbellard     int index_in_cluster;
527095a9c58Saliguori     int n_end;
52868d100e9SKevin Wolf     int ret;
529faf575c1SFrediano Ziglio     int cur_nr_sectors; /* number of sectors in current iteration */
530c2bdd990SFrediano Ziglio     uint64_t cluster_offset;
5313fc48d09SFrediano Ziglio     QEMUIOVector hd_qiov;
5323fc48d09SFrediano Ziglio     uint64_t bytes_done = 0;
5333fc48d09SFrediano Ziglio     uint8_t *cluster_data = NULL;
5348e217d53SKevin Wolf     QCowL2Meta l2meta = {
5358e217d53SKevin Wolf         .nb_clusters = 0,
5368e217d53SKevin Wolf     };
537c2271403SFrediano Ziglio 
538c2271403SFrediano Ziglio     qemu_co_queue_init(&l2meta.dependent_requests);
539585f8587Sbellard 
5403fc48d09SFrediano Ziglio     qemu_iovec_init(&hd_qiov, qiov->niov);
541585f8587Sbellard 
5423fc48d09SFrediano Ziglio     s->cluster_cache_offset = -1; /* disable compressed cache */
5433fc48d09SFrediano Ziglio 
5443fc48d09SFrediano Ziglio     qemu_co_mutex_lock(&s->lock);
5453fc48d09SFrediano Ziglio 
5463fc48d09SFrediano Ziglio     while (remaining_sectors != 0) {
5473fc48d09SFrediano Ziglio 
5483fc48d09SFrediano Ziglio         index_in_cluster = sector_num & (s->cluster_sectors - 1);
5493fc48d09SFrediano Ziglio         n_end = index_in_cluster + remaining_sectors;
550095a9c58Saliguori         if (s->crypt_method &&
5515ebaa27eSFrediano Ziglio             n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) {
552095a9c58Saliguori             n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
5535ebaa27eSFrediano Ziglio         }
554095a9c58Saliguori 
5553fc48d09SFrediano Ziglio         ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
556c2271403SFrediano Ziglio             index_in_cluster, n_end, &cur_nr_sectors, &l2meta);
557148da7eaSKevin Wolf         if (ret < 0) {
5583fc48d09SFrediano Ziglio             goto fail;
559148da7eaSKevin Wolf         }
560148da7eaSKevin Wolf 
561c2bdd990SFrediano Ziglio         cluster_offset = l2meta.cluster_offset;
562c2bdd990SFrediano Ziglio         assert((cluster_offset & 511) == 0);
563148da7eaSKevin Wolf 
5643fc48d09SFrediano Ziglio         qemu_iovec_reset(&hd_qiov);
5653fc48d09SFrediano Ziglio         qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
566faf575c1SFrediano Ziglio             cur_nr_sectors * 512);
5676f5f060bSKevin Wolf 
568585f8587Sbellard         if (s->crypt_method) {
5693fc48d09SFrediano Ziglio             if (!cluster_data) {
570dea43a65SFrediano Ziglio                 cluster_data = qemu_blockalign(bs, QCOW_MAX_CRYPT_CLUSTERS *
571095a9c58Saliguori                                                  s->cluster_size);
572585f8587Sbellard             }
5736f5f060bSKevin Wolf 
5743fc48d09SFrediano Ziglio             assert(hd_qiov.size <=
5755ebaa27eSFrediano Ziglio                    QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
5763fc48d09SFrediano Ziglio             qemu_iovec_to_buffer(&hd_qiov, cluster_data);
5776f5f060bSKevin Wolf 
5783fc48d09SFrediano Ziglio             qcow2_encrypt_sectors(s, sector_num, cluster_data,
5793fc48d09SFrediano Ziglio                 cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
5806f5f060bSKevin Wolf 
5813fc48d09SFrediano Ziglio             qemu_iovec_reset(&hd_qiov);
5823fc48d09SFrediano Ziglio             qemu_iovec_add(&hd_qiov, cluster_data,
583faf575c1SFrediano Ziglio                 cur_nr_sectors * 512);
584585f8587Sbellard         }
5856f5f060bSKevin Wolf 
58666f82ceeSKevin Wolf         BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
58768d100e9SKevin Wolf         qemu_co_mutex_unlock(&s->lock);
58868d100e9SKevin Wolf         ret = bdrv_co_writev(bs->file,
589c2bdd990SFrediano Ziglio                              (cluster_offset >> 9) + index_in_cluster,
5903fc48d09SFrediano Ziglio                              cur_nr_sectors, &hd_qiov);
59168d100e9SKevin Wolf         qemu_co_mutex_lock(&s->lock);
59268d100e9SKevin Wolf         if (ret < 0) {
5933fc48d09SFrediano Ziglio             goto fail;
594171e3d6bSKevin Wolf         }
595f141eafeSaliguori 
596c2271403SFrediano Ziglio         ret = qcow2_alloc_cluster_link_l2(bs, &l2meta);
597faf575c1SFrediano Ziglio         if (ret < 0) {
5983fc48d09SFrediano Ziglio             goto fail;
599faf575c1SFrediano Ziglio         }
600faf575c1SFrediano Ziglio 
6010fa9131aSKevin Wolf         run_dependent_requests(s, &l2meta);
6020fa9131aSKevin Wolf 
6033fc48d09SFrediano Ziglio         remaining_sectors -= cur_nr_sectors;
6043fc48d09SFrediano Ziglio         sector_num += cur_nr_sectors;
6053fc48d09SFrediano Ziglio         bytes_done += cur_nr_sectors * 512;
6065ebaa27eSFrediano Ziglio     }
6073fc48d09SFrediano Ziglio     ret = 0;
608faf575c1SFrediano Ziglio 
6093fc48d09SFrediano Ziglio fail:
6100fa9131aSKevin Wolf     run_dependent_requests(s, &l2meta);
6110fa9131aSKevin Wolf 
61268d100e9SKevin Wolf     qemu_co_mutex_unlock(&s->lock);
613585f8587Sbellard 
6143fc48d09SFrediano Ziglio     qemu_iovec_destroy(&hd_qiov);
615dea43a65SFrediano Ziglio     qemu_vfree(cluster_data);
61642496d62SKevin Wolf 
61768d100e9SKevin Wolf     return ret;
618585f8587Sbellard }
619585f8587Sbellard 
6207c80ab3fSJes Sorensen static void qcow2_close(BlockDriverState *bs)
621585f8587Sbellard {
622585f8587Sbellard     BDRVQcowState *s = bs->opaque;
6237267c094SAnthony Liguori     g_free(s->l1_table);
62429c1a730SKevin Wolf 
62529c1a730SKevin Wolf     qcow2_cache_flush(bs, s->l2_table_cache);
62629c1a730SKevin Wolf     qcow2_cache_flush(bs, s->refcount_block_cache);
62729c1a730SKevin Wolf 
62829c1a730SKevin Wolf     qcow2_cache_destroy(bs, s->l2_table_cache);
62929c1a730SKevin Wolf     qcow2_cache_destroy(bs, s->refcount_block_cache);
63029c1a730SKevin Wolf 
6317267c094SAnthony Liguori     g_free(s->cluster_cache);
632dea43a65SFrediano Ziglio     qemu_vfree(s->cluster_data);
633ed6ccf0fSKevin Wolf     qcow2_refcount_close(bs);
634585f8587Sbellard }
635585f8587Sbellard 
636*06d9260fSAnthony Liguori static void qcow2_invalidate_cache(BlockDriverState *bs)
637*06d9260fSAnthony Liguori {
638*06d9260fSAnthony Liguori     BDRVQcowState *s = bs->opaque;
639*06d9260fSAnthony Liguori     int flags = s->flags;
640*06d9260fSAnthony Liguori     AES_KEY aes_encrypt_key;
641*06d9260fSAnthony Liguori     AES_KEY aes_decrypt_key;
642*06d9260fSAnthony Liguori     uint32_t crypt_method = 0;
643*06d9260fSAnthony Liguori 
644*06d9260fSAnthony Liguori     /*
645*06d9260fSAnthony Liguori      * Backing files are read-only which makes all of their metadata immutable,
646*06d9260fSAnthony Liguori      * that means we don't have to worry about reopening them here.
647*06d9260fSAnthony Liguori      */
648*06d9260fSAnthony Liguori 
649*06d9260fSAnthony Liguori     if (s->crypt_method) {
650*06d9260fSAnthony Liguori         crypt_method = s->crypt_method;
651*06d9260fSAnthony Liguori         memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key));
652*06d9260fSAnthony Liguori         memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key));
653*06d9260fSAnthony Liguori     }
654*06d9260fSAnthony Liguori 
655*06d9260fSAnthony Liguori     qcow2_close(bs);
656*06d9260fSAnthony Liguori 
657*06d9260fSAnthony Liguori     memset(s, 0, sizeof(BDRVQcowState));
658*06d9260fSAnthony Liguori     qcow2_open(bs, flags);
659*06d9260fSAnthony Liguori 
660*06d9260fSAnthony Liguori     if (crypt_method) {
661*06d9260fSAnthony Liguori         s->crypt_method = crypt_method;
662*06d9260fSAnthony Liguori         memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key));
663*06d9260fSAnthony Liguori         memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key));
664*06d9260fSAnthony Liguori     }
665*06d9260fSAnthony Liguori }
666*06d9260fSAnthony Liguori 
667756e6736SKevin Wolf /*
668756e6736SKevin Wolf  * Updates the variable length parts of the qcow2 header, i.e. the backing file
669756e6736SKevin Wolf  * name and all extensions. qcow2 was not designed to allow such changes, so if
670756e6736SKevin Wolf  * we run out of space (we can only use the first cluster) this function may
671756e6736SKevin Wolf  * fail.
672756e6736SKevin Wolf  *
673756e6736SKevin Wolf  * Returns 0 on success, -errno in error cases.
674756e6736SKevin Wolf  */
675756e6736SKevin Wolf static int qcow2_update_ext_header(BlockDriverState *bs,
676756e6736SKevin Wolf     const char *backing_file, const char *backing_fmt)
677756e6736SKevin Wolf {
678756e6736SKevin Wolf     size_t backing_file_len = 0;
679756e6736SKevin Wolf     size_t backing_fmt_len = 0;
680756e6736SKevin Wolf     BDRVQcowState *s = bs->opaque;
681756e6736SKevin Wolf     QCowExtension ext_backing_fmt = {0, 0};
682756e6736SKevin Wolf     int ret;
683756e6736SKevin Wolf 
684756e6736SKevin Wolf     /* Backing file format doesn't make sense without a backing file */
685756e6736SKevin Wolf     if (backing_fmt && !backing_file) {
686756e6736SKevin Wolf         return -EINVAL;
687756e6736SKevin Wolf     }
688756e6736SKevin Wolf 
689756e6736SKevin Wolf     /* Prepare the backing file format extension if needed */
690756e6736SKevin Wolf     if (backing_fmt) {
691756e6736SKevin Wolf         ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
6927c80ab3fSJes Sorensen         ext_backing_fmt.magic = cpu_to_be32(QCOW2_EXT_MAGIC_BACKING_FORMAT);
693756e6736SKevin Wolf         backing_fmt_len = ((sizeof(ext_backing_fmt)
694756e6736SKevin Wolf             + strlen(backing_fmt) + 7) & ~7);
695756e6736SKevin Wolf     }
696756e6736SKevin Wolf 
697756e6736SKevin Wolf     /* Check if we can fit the new header into the first cluster */
698756e6736SKevin Wolf     if (backing_file) {
699756e6736SKevin Wolf         backing_file_len = strlen(backing_file);
700756e6736SKevin Wolf     }
701756e6736SKevin Wolf 
702756e6736SKevin Wolf     size_t header_size = sizeof(QCowHeader) + backing_file_len
703756e6736SKevin Wolf         + backing_fmt_len;
704756e6736SKevin Wolf 
705756e6736SKevin Wolf     if (header_size > s->cluster_size) {
706756e6736SKevin Wolf         return -ENOSPC;
707756e6736SKevin Wolf     }
708756e6736SKevin Wolf 
709756e6736SKevin Wolf     /* Rewrite backing file name and qcow2 extensions */
710756e6736SKevin Wolf     size_t ext_size = header_size - sizeof(QCowHeader);
711756e6736SKevin Wolf     uint8_t buf[ext_size];
712756e6736SKevin Wolf     size_t offset = 0;
713756e6736SKevin Wolf     size_t backing_file_offset = 0;
714756e6736SKevin Wolf 
715756e6736SKevin Wolf     if (backing_file) {
716756e6736SKevin Wolf         if (backing_fmt) {
717756e6736SKevin Wolf             int padding = backing_fmt_len -
718756e6736SKevin Wolf                 (sizeof(ext_backing_fmt) + strlen(backing_fmt));
719756e6736SKevin Wolf 
720756e6736SKevin Wolf             memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
721756e6736SKevin Wolf             offset += sizeof(ext_backing_fmt);
722756e6736SKevin Wolf 
723756e6736SKevin Wolf             memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
724756e6736SKevin Wolf             offset += strlen(backing_fmt);
725756e6736SKevin Wolf 
726756e6736SKevin Wolf             memset(buf + offset, 0, padding);
727756e6736SKevin Wolf             offset += padding;
728756e6736SKevin Wolf         }
729756e6736SKevin Wolf 
730756e6736SKevin Wolf         memcpy(buf + offset, backing_file, backing_file_len);
731756e6736SKevin Wolf         backing_file_offset = sizeof(QCowHeader) + offset;
732756e6736SKevin Wolf     }
733756e6736SKevin Wolf 
7348b3b7206SKevin Wolf     ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
735756e6736SKevin Wolf     if (ret < 0) {
736756e6736SKevin Wolf         goto fail;
737756e6736SKevin Wolf     }
738756e6736SKevin Wolf 
739756e6736SKevin Wolf     /* Update header fields */
740756e6736SKevin Wolf     uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
741756e6736SKevin Wolf     uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
742756e6736SKevin Wolf 
7438b3b7206SKevin Wolf     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
744756e6736SKevin Wolf         &be_backing_file_offset, sizeof(uint64_t));
745756e6736SKevin Wolf     if (ret < 0) {
746756e6736SKevin Wolf         goto fail;
747756e6736SKevin Wolf     }
748756e6736SKevin Wolf 
7498b3b7206SKevin Wolf     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
750756e6736SKevin Wolf         &be_backing_file_size, sizeof(uint32_t));
751756e6736SKevin Wolf     if (ret < 0) {
752756e6736SKevin Wolf         goto fail;
753756e6736SKevin Wolf     }
754756e6736SKevin Wolf 
755756e6736SKevin Wolf     ret = 0;
756756e6736SKevin Wolf fail:
757756e6736SKevin Wolf     return ret;
758756e6736SKevin Wolf }
759756e6736SKevin Wolf 
760756e6736SKevin Wolf static int qcow2_change_backing_file(BlockDriverState *bs,
761756e6736SKevin Wolf     const char *backing_file, const char *backing_fmt)
762756e6736SKevin Wolf {
763756e6736SKevin Wolf     return qcow2_update_ext_header(bs, backing_file, backing_fmt);
764756e6736SKevin Wolf }
765756e6736SKevin Wolf 
766a35e1c17SKevin Wolf static int preallocate(BlockDriverState *bs)
767a35e1c17SKevin Wolf {
768a35e1c17SKevin Wolf     uint64_t nb_sectors;
769a35e1c17SKevin Wolf     uint64_t offset;
770a35e1c17SKevin Wolf     int num;
771148da7eaSKevin Wolf     int ret;
772a35e1c17SKevin Wolf     QCowL2Meta meta;
773a35e1c17SKevin Wolf 
774a35e1c17SKevin Wolf     nb_sectors = bdrv_getlength(bs) >> 9;
775a35e1c17SKevin Wolf     offset = 0;
77668d100e9SKevin Wolf     qemu_co_queue_init(&meta.dependent_requests);
777148da7eaSKevin Wolf     meta.cluster_offset = 0;
778a35e1c17SKevin Wolf 
779a35e1c17SKevin Wolf     while (nb_sectors) {
780a35e1c17SKevin Wolf         num = MIN(nb_sectors, INT_MAX >> 9);
781148da7eaSKevin Wolf         ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
782148da7eaSKevin Wolf         if (ret < 0) {
78319dbcbf7SKevin Wolf             return ret;
784a35e1c17SKevin Wolf         }
785a35e1c17SKevin Wolf 
78619dbcbf7SKevin Wolf         ret = qcow2_alloc_cluster_link_l2(bs, &meta);
78719dbcbf7SKevin Wolf         if (ret < 0) {
788148da7eaSKevin Wolf             qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
78919dbcbf7SKevin Wolf             return ret;
790a35e1c17SKevin Wolf         }
791a35e1c17SKevin Wolf 
792f214978aSKevin Wolf         /* There are no dependent requests, but we need to remove our request
793f214978aSKevin Wolf          * from the list of in-flight requests */
79468d100e9SKevin Wolf         run_dependent_requests(bs->opaque, &meta);
795f214978aSKevin Wolf 
796a35e1c17SKevin Wolf         /* TODO Preallocate data if requested */
797a35e1c17SKevin Wolf 
798a35e1c17SKevin Wolf         nb_sectors -= num;
799a35e1c17SKevin Wolf         offset += num << 9;
800a35e1c17SKevin Wolf     }
801a35e1c17SKevin Wolf 
802a35e1c17SKevin Wolf     /*
803a35e1c17SKevin Wolf      * It is expected that the image file is large enough to actually contain
804a35e1c17SKevin Wolf      * all of the allocated clusters (otherwise we get failing reads after
805a35e1c17SKevin Wolf      * EOF). Extend the image to the last allocated sector.
806a35e1c17SKevin Wolf      */
807148da7eaSKevin Wolf     if (meta.cluster_offset != 0) {
808ea80b906SKevin Wolf         uint8_t buf[512];
809ea80b906SKevin Wolf         memset(buf, 0, 512);
81019dbcbf7SKevin Wolf         ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
81119dbcbf7SKevin Wolf         if (ret < 0) {
81219dbcbf7SKevin Wolf             return ret;
81319dbcbf7SKevin Wolf         }
814a35e1c17SKevin Wolf     }
815a35e1c17SKevin Wolf 
816a35e1c17SKevin Wolf     return 0;
817a35e1c17SKevin Wolf }
818a35e1c17SKevin Wolf 
8197c80ab3fSJes Sorensen static int qcow2_create2(const char *filename, int64_t total_size,
820a9420734SKevin Wolf                          const char *backing_file, const char *backing_format,
821a9420734SKevin Wolf                          int flags, size_t cluster_size, int prealloc,
822a9420734SKevin Wolf                          QEMUOptionParameter *options)
823a9420734SKevin Wolf {
824a9420734SKevin Wolf     /* Calulate cluster_bits */
825a9420734SKevin Wolf     int cluster_bits;
826a9420734SKevin Wolf     cluster_bits = ffs(cluster_size) - 1;
827a9420734SKevin Wolf     if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
828a9420734SKevin Wolf         (1 << cluster_bits) != cluster_size)
829a9420734SKevin Wolf     {
830a9420734SKevin Wolf         error_report(
8316daf194dSMarkus Armbruster             "Cluster size must be a power of two between %d and %dk",
832a9420734SKevin Wolf             1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
833a9420734SKevin Wolf         return -EINVAL;
834a9420734SKevin Wolf     }
835a9420734SKevin Wolf 
836a9420734SKevin Wolf     /*
837a9420734SKevin Wolf      * Open the image file and write a minimal qcow2 header.
838a9420734SKevin Wolf      *
839a9420734SKevin Wolf      * We keep things simple and start with a zero-sized image. We also
840a9420734SKevin Wolf      * do without refcount blocks or a L1 table for now. We'll fix the
841a9420734SKevin Wolf      * inconsistency later.
842a9420734SKevin Wolf      *
843a9420734SKevin Wolf      * We do need a refcount table because growing the refcount table means
844a9420734SKevin Wolf      * allocating two new refcount blocks - the seconds of which would be at
845a9420734SKevin Wolf      * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
846a9420734SKevin Wolf      * size for any qcow2 image.
847a9420734SKevin Wolf      */
848a9420734SKevin Wolf     BlockDriverState* bs;
849a9420734SKevin Wolf     QCowHeader header;
850a9420734SKevin Wolf     uint8_t* refcount_table;
851a9420734SKevin Wolf     int ret;
852a9420734SKevin Wolf 
853a9420734SKevin Wolf     ret = bdrv_create_file(filename, options);
854a9420734SKevin Wolf     if (ret < 0) {
855a9420734SKevin Wolf         return ret;
856a9420734SKevin Wolf     }
857a9420734SKevin Wolf 
858a9420734SKevin Wolf     ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR);
859a9420734SKevin Wolf     if (ret < 0) {
860a9420734SKevin Wolf         return ret;
861a9420734SKevin Wolf     }
862a9420734SKevin Wolf 
863a9420734SKevin Wolf     /* Write the header */
864a9420734SKevin Wolf     memset(&header, 0, sizeof(header));
865a9420734SKevin Wolf     header.magic = cpu_to_be32(QCOW_MAGIC);
866a9420734SKevin Wolf     header.version = cpu_to_be32(QCOW_VERSION);
867a9420734SKevin Wolf     header.cluster_bits = cpu_to_be32(cluster_bits);
868a9420734SKevin Wolf     header.size = cpu_to_be64(0);
869a9420734SKevin Wolf     header.l1_table_offset = cpu_to_be64(0);
870a9420734SKevin Wolf     header.l1_size = cpu_to_be32(0);
871a9420734SKevin Wolf     header.refcount_table_offset = cpu_to_be64(cluster_size);
872a9420734SKevin Wolf     header.refcount_table_clusters = cpu_to_be32(1);
873a9420734SKevin Wolf 
874a9420734SKevin Wolf     if (flags & BLOCK_FLAG_ENCRYPT) {
875a9420734SKevin Wolf         header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
876a9420734SKevin Wolf     } else {
877a9420734SKevin Wolf         header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
878a9420734SKevin Wolf     }
879a9420734SKevin Wolf 
880a9420734SKevin Wolf     ret = bdrv_pwrite(bs, 0, &header, sizeof(header));
881a9420734SKevin Wolf     if (ret < 0) {
882a9420734SKevin Wolf         goto out;
883a9420734SKevin Wolf     }
884a9420734SKevin Wolf 
885a9420734SKevin Wolf     /* Write an empty refcount table */
8867267c094SAnthony Liguori     refcount_table = g_malloc0(cluster_size);
887a9420734SKevin Wolf     ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size);
8887267c094SAnthony Liguori     g_free(refcount_table);
889a9420734SKevin Wolf 
890a9420734SKevin Wolf     if (ret < 0) {
891a9420734SKevin Wolf         goto out;
892a9420734SKevin Wolf     }
893a9420734SKevin Wolf 
894a9420734SKevin Wolf     bdrv_close(bs);
895a9420734SKevin Wolf 
896a9420734SKevin Wolf     /*
897a9420734SKevin Wolf      * And now open the image and make it consistent first (i.e. increase the
898a9420734SKevin Wolf      * refcount of the cluster that is occupied by the header and the refcount
899a9420734SKevin Wolf      * table)
900a9420734SKevin Wolf      */
901a9420734SKevin Wolf     BlockDriver* drv = bdrv_find_format("qcow2");
902a9420734SKevin Wolf     assert(drv != NULL);
903e1a7107fSKevin Wolf     ret = bdrv_open(bs, filename,
904e1a7107fSKevin Wolf         BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv);
905a9420734SKevin Wolf     if (ret < 0) {
906a9420734SKevin Wolf         goto out;
907a9420734SKevin Wolf     }
908a9420734SKevin Wolf 
909a9420734SKevin Wolf     ret = qcow2_alloc_clusters(bs, 2 * cluster_size);
910a9420734SKevin Wolf     if (ret < 0) {
911a9420734SKevin Wolf         goto out;
912a9420734SKevin Wolf 
913a9420734SKevin Wolf     } else if (ret != 0) {
914a9420734SKevin Wolf         error_report("Huh, first cluster in empty image is already in use?");
915a9420734SKevin Wolf         abort();
916a9420734SKevin Wolf     }
917a9420734SKevin Wolf 
918a9420734SKevin Wolf     /* Okay, now that we have a valid image, let's give it the right size */
919a9420734SKevin Wolf     ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE);
920a9420734SKevin Wolf     if (ret < 0) {
921a9420734SKevin Wolf         goto out;
922a9420734SKevin Wolf     }
923a9420734SKevin Wolf 
924a9420734SKevin Wolf     /* Want a backing file? There you go.*/
925a9420734SKevin Wolf     if (backing_file) {
926a9420734SKevin Wolf         ret = bdrv_change_backing_file(bs, backing_file, backing_format);
927a9420734SKevin Wolf         if (ret < 0) {
928a9420734SKevin Wolf             goto out;
929a9420734SKevin Wolf         }
930a9420734SKevin Wolf     }
931a9420734SKevin Wolf 
932a9420734SKevin Wolf     /* And if we're supposed to preallocate metadata, do that now */
933a9420734SKevin Wolf     if (prealloc) {
934a9420734SKevin Wolf         ret = preallocate(bs);
935a9420734SKevin Wolf         if (ret < 0) {
936a9420734SKevin Wolf             goto out;
937a9420734SKevin Wolf         }
938a9420734SKevin Wolf     }
939a9420734SKevin Wolf 
940a9420734SKevin Wolf     ret = 0;
941a9420734SKevin Wolf out:
942a9420734SKevin Wolf     bdrv_delete(bs);
943a9420734SKevin Wolf     return ret;
944a9420734SKevin Wolf }
945de5f3f40SKevin Wolf 
9467c80ab3fSJes Sorensen static int qcow2_create(const char *filename, QEMUOptionParameter *options)
947de5f3f40SKevin Wolf {
948de5f3f40SKevin Wolf     const char *backing_file = NULL;
949de5f3f40SKevin Wolf     const char *backing_fmt = NULL;
950de5f3f40SKevin Wolf     uint64_t sectors = 0;
951de5f3f40SKevin Wolf     int flags = 0;
95299cce9faSKevin Wolf     size_t cluster_size = DEFAULT_CLUSTER_SIZE;
953de5f3f40SKevin Wolf     int prealloc = 0;
954de5f3f40SKevin Wolf 
955de5f3f40SKevin Wolf     /* Read out options */
956de5f3f40SKevin Wolf     while (options && options->name) {
957de5f3f40SKevin Wolf         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
958de5f3f40SKevin Wolf             sectors = options->value.n / 512;
959de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
960de5f3f40SKevin Wolf             backing_file = options->value.s;
961de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
962de5f3f40SKevin Wolf             backing_fmt = options->value.s;
963de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
964de5f3f40SKevin Wolf             flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
965de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
966de5f3f40SKevin Wolf             if (options->value.n) {
967de5f3f40SKevin Wolf                 cluster_size = options->value.n;
968de5f3f40SKevin Wolf             }
969de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
970de5f3f40SKevin Wolf             if (!options->value.s || !strcmp(options->value.s, "off")) {
971de5f3f40SKevin Wolf                 prealloc = 0;
972de5f3f40SKevin Wolf             } else if (!strcmp(options->value.s, "metadata")) {
973de5f3f40SKevin Wolf                 prealloc = 1;
974de5f3f40SKevin Wolf             } else {
975de5f3f40SKevin Wolf                 fprintf(stderr, "Invalid preallocation mode: '%s'\n",
976de5f3f40SKevin Wolf                     options->value.s);
977de5f3f40SKevin Wolf                 return -EINVAL;
978de5f3f40SKevin Wolf             }
979de5f3f40SKevin Wolf         }
980de5f3f40SKevin Wolf         options++;
981de5f3f40SKevin Wolf     }
982de5f3f40SKevin Wolf 
983de5f3f40SKevin Wolf     if (backing_file && prealloc) {
984de5f3f40SKevin Wolf         fprintf(stderr, "Backing file and preallocation cannot be used at "
985de5f3f40SKevin Wolf             "the same time\n");
986de5f3f40SKevin Wolf         return -EINVAL;
987de5f3f40SKevin Wolf     }
988de5f3f40SKevin Wolf 
9897c80ab3fSJes Sorensen     return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
990a9420734SKevin Wolf                          cluster_size, prealloc, options);
991de5f3f40SKevin Wolf }
992de5f3f40SKevin Wolf 
9937c80ab3fSJes Sorensen static int qcow2_make_empty(BlockDriverState *bs)
99420d97356SBlue Swirl {
99520d97356SBlue Swirl #if 0
99620d97356SBlue Swirl     /* XXX: not correct */
99720d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
99820d97356SBlue Swirl     uint32_t l1_length = s->l1_size * sizeof(uint64_t);
99920d97356SBlue Swirl     int ret;
100020d97356SBlue Swirl 
100120d97356SBlue Swirl     memset(s->l1_table, 0, l1_length);
100266f82ceeSKevin Wolf     if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
100320d97356SBlue Swirl         return -1;
100466f82ceeSKevin Wolf     ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
100520d97356SBlue Swirl     if (ret < 0)
100620d97356SBlue Swirl         return ret;
100720d97356SBlue Swirl 
100820d97356SBlue Swirl     l2_cache_reset(bs);
100920d97356SBlue Swirl #endif
101020d97356SBlue Swirl     return 0;
101120d97356SBlue Swirl }
101220d97356SBlue Swirl 
10136db39ae2SPaolo Bonzini static coroutine_fn int qcow2_co_discard(BlockDriverState *bs,
10146db39ae2SPaolo Bonzini     int64_t sector_num, int nb_sectors)
10155ea929e3SKevin Wolf {
10166db39ae2SPaolo Bonzini     int ret;
10176db39ae2SPaolo Bonzini     BDRVQcowState *s = bs->opaque;
10186db39ae2SPaolo Bonzini 
10196db39ae2SPaolo Bonzini     qemu_co_mutex_lock(&s->lock);
10206db39ae2SPaolo Bonzini     ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS,
10215ea929e3SKevin Wolf         nb_sectors);
10226db39ae2SPaolo Bonzini     qemu_co_mutex_unlock(&s->lock);
10236db39ae2SPaolo Bonzini     return ret;
10245ea929e3SKevin Wolf }
10255ea929e3SKevin Wolf 
1026419b19d9SStefan Hajnoczi static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
1027419b19d9SStefan Hajnoczi {
1028419b19d9SStefan Hajnoczi     BDRVQcowState *s = bs->opaque;
1029419b19d9SStefan Hajnoczi     int ret, new_l1_size;
1030419b19d9SStefan Hajnoczi 
1031419b19d9SStefan Hajnoczi     if (offset & 511) {
1032419b19d9SStefan Hajnoczi         return -EINVAL;
1033419b19d9SStefan Hajnoczi     }
1034419b19d9SStefan Hajnoczi 
1035419b19d9SStefan Hajnoczi     /* cannot proceed if image has snapshots */
1036419b19d9SStefan Hajnoczi     if (s->nb_snapshots) {
1037419b19d9SStefan Hajnoczi         return -ENOTSUP;
1038419b19d9SStefan Hajnoczi     }
1039419b19d9SStefan Hajnoczi 
1040419b19d9SStefan Hajnoczi     /* shrinking is currently not supported */
1041419b19d9SStefan Hajnoczi     if (offset < bs->total_sectors * 512) {
1042419b19d9SStefan Hajnoczi         return -ENOTSUP;
1043419b19d9SStefan Hajnoczi     }
1044419b19d9SStefan Hajnoczi 
1045419b19d9SStefan Hajnoczi     new_l1_size = size_to_l1(s, offset);
104672893756SStefan Hajnoczi     ret = qcow2_grow_l1_table(bs, new_l1_size, true);
1047419b19d9SStefan Hajnoczi     if (ret < 0) {
1048419b19d9SStefan Hajnoczi         return ret;
1049419b19d9SStefan Hajnoczi     }
1050419b19d9SStefan Hajnoczi 
1051419b19d9SStefan Hajnoczi     /* write updated header.size */
1052419b19d9SStefan Hajnoczi     offset = cpu_to_be64(offset);
10538b3b7206SKevin Wolf     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
1054419b19d9SStefan Hajnoczi                            &offset, sizeof(uint64_t));
1055419b19d9SStefan Hajnoczi     if (ret < 0) {
1056419b19d9SStefan Hajnoczi         return ret;
1057419b19d9SStefan Hajnoczi     }
1058419b19d9SStefan Hajnoczi 
1059419b19d9SStefan Hajnoczi     s->l1_vm_state_index = new_l1_size;
1060419b19d9SStefan Hajnoczi     return 0;
1061419b19d9SStefan Hajnoczi }
1062419b19d9SStefan Hajnoczi 
106320d97356SBlue Swirl /* XXX: put compressed sectors first, then all the cluster aligned
106420d97356SBlue Swirl    tables to avoid losing bytes in alignment */
10657c80ab3fSJes Sorensen static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num,
106620d97356SBlue Swirl                                   const uint8_t *buf, int nb_sectors)
106720d97356SBlue Swirl {
106820d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
106920d97356SBlue Swirl     z_stream strm;
107020d97356SBlue Swirl     int ret, out_len;
107120d97356SBlue Swirl     uint8_t *out_buf;
107220d97356SBlue Swirl     uint64_t cluster_offset;
107320d97356SBlue Swirl 
107420d97356SBlue Swirl     if (nb_sectors == 0) {
107520d97356SBlue Swirl         /* align end of file to a sector boundary to ease reading with
107620d97356SBlue Swirl            sector based I/Os */
107766f82ceeSKevin Wolf         cluster_offset = bdrv_getlength(bs->file);
107820d97356SBlue Swirl         cluster_offset = (cluster_offset + 511) & ~511;
107966f82ceeSKevin Wolf         bdrv_truncate(bs->file, cluster_offset);
108020d97356SBlue Swirl         return 0;
108120d97356SBlue Swirl     }
108220d97356SBlue Swirl 
108320d97356SBlue Swirl     if (nb_sectors != s->cluster_sectors)
108420d97356SBlue Swirl         return -EINVAL;
108520d97356SBlue Swirl 
10867267c094SAnthony Liguori     out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
108720d97356SBlue Swirl 
108820d97356SBlue Swirl     /* best compression, small window, no zlib header */
108920d97356SBlue Swirl     memset(&strm, 0, sizeof(strm));
109020d97356SBlue Swirl     ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
109120d97356SBlue Swirl                        Z_DEFLATED, -12,
109220d97356SBlue Swirl                        9, Z_DEFAULT_STRATEGY);
109320d97356SBlue Swirl     if (ret != 0) {
10948f1efd00SKevin Wolf         ret = -EINVAL;
10958f1efd00SKevin Wolf         goto fail;
109620d97356SBlue Swirl     }
109720d97356SBlue Swirl 
109820d97356SBlue Swirl     strm.avail_in = s->cluster_size;
109920d97356SBlue Swirl     strm.next_in = (uint8_t *)buf;
110020d97356SBlue Swirl     strm.avail_out = s->cluster_size;
110120d97356SBlue Swirl     strm.next_out = out_buf;
110220d97356SBlue Swirl 
110320d97356SBlue Swirl     ret = deflate(&strm, Z_FINISH);
110420d97356SBlue Swirl     if (ret != Z_STREAM_END && ret != Z_OK) {
110520d97356SBlue Swirl         deflateEnd(&strm);
11068f1efd00SKevin Wolf         ret = -EINVAL;
11078f1efd00SKevin Wolf         goto fail;
110820d97356SBlue Swirl     }
110920d97356SBlue Swirl     out_len = strm.next_out - out_buf;
111020d97356SBlue Swirl 
111120d97356SBlue Swirl     deflateEnd(&strm);
111220d97356SBlue Swirl 
111320d97356SBlue Swirl     if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
111420d97356SBlue Swirl         /* could not compress: write normal cluster */
11158f1efd00SKevin Wolf         ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
11168f1efd00SKevin Wolf         if (ret < 0) {
11178f1efd00SKevin Wolf             goto fail;
11188f1efd00SKevin Wolf         }
111920d97356SBlue Swirl     } else {
112020d97356SBlue Swirl         cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
112120d97356SBlue Swirl             sector_num << 9, out_len);
11228f1efd00SKevin Wolf         if (!cluster_offset) {
11238f1efd00SKevin Wolf             ret = -EIO;
11248f1efd00SKevin Wolf             goto fail;
11258f1efd00SKevin Wolf         }
112620d97356SBlue Swirl         cluster_offset &= s->cluster_offset_mask;
112766f82ceeSKevin Wolf         BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
11288f1efd00SKevin Wolf         ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
11298f1efd00SKevin Wolf         if (ret < 0) {
11308f1efd00SKevin Wolf             goto fail;
113120d97356SBlue Swirl         }
113220d97356SBlue Swirl     }
113320d97356SBlue Swirl 
11348f1efd00SKevin Wolf     ret = 0;
11358f1efd00SKevin Wolf fail:
11367267c094SAnthony Liguori     g_free(out_buf);
11378f1efd00SKevin Wolf     return ret;
113820d97356SBlue Swirl }
113920d97356SBlue Swirl 
1140eb489bb1SKevin Wolf static int qcow2_co_flush_to_os(BlockDriverState *bs)
114120d97356SBlue Swirl {
114229c1a730SKevin Wolf     BDRVQcowState *s = bs->opaque;
114329c1a730SKevin Wolf     int ret;
114429c1a730SKevin Wolf 
11458b94ff85SPaolo Bonzini     qemu_co_mutex_lock(&s->lock);
114629c1a730SKevin Wolf     ret = qcow2_cache_flush(bs, s->l2_table_cache);
114729c1a730SKevin Wolf     if (ret < 0) {
1148c95de7e2SDong Xu Wang         qemu_co_mutex_unlock(&s->lock);
11498b94ff85SPaolo Bonzini         return ret;
115029c1a730SKevin Wolf     }
115129c1a730SKevin Wolf 
115229c1a730SKevin Wolf     ret = qcow2_cache_flush(bs, s->refcount_block_cache);
115329c1a730SKevin Wolf     if (ret < 0) {
1154c95de7e2SDong Xu Wang         qemu_co_mutex_unlock(&s->lock);
11558b94ff85SPaolo Bonzini         return ret;
115629c1a730SKevin Wolf     }
11578b94ff85SPaolo Bonzini     qemu_co_mutex_unlock(&s->lock);
115829c1a730SKevin Wolf 
1159eb489bb1SKevin Wolf     return 0;
1160eb489bb1SKevin Wolf }
1161eb489bb1SKevin Wolf 
1162eb489bb1SKevin Wolf static int qcow2_co_flush_to_disk(BlockDriverState *bs)
1163eb489bb1SKevin Wolf {
11648b94ff85SPaolo Bonzini     return bdrv_co_flush(bs->file);
116520d97356SBlue Swirl }
116620d97356SBlue Swirl 
11677c80ab3fSJes Sorensen static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
116820d97356SBlue Swirl {
116920d97356SBlue Swirl 	return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
117020d97356SBlue Swirl }
117120d97356SBlue Swirl 
11727c80ab3fSJes Sorensen static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
117320d97356SBlue Swirl {
117420d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
117520d97356SBlue Swirl     bdi->cluster_size = s->cluster_size;
11767c80ab3fSJes Sorensen     bdi->vm_state_offset = qcow2_vm_state_offset(s);
117720d97356SBlue Swirl     return 0;
117820d97356SBlue Swirl }
117920d97356SBlue Swirl 
118020d97356SBlue Swirl 
11817c80ab3fSJes Sorensen static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result)
118220d97356SBlue Swirl {
11839ac228e0SKevin Wolf     return qcow2_check_refcounts(bs, result);
118420d97356SBlue Swirl }
118520d97356SBlue Swirl 
118620d97356SBlue Swirl #if 0
118720d97356SBlue Swirl static void dump_refcounts(BlockDriverState *bs)
118820d97356SBlue Swirl {
118920d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
119020d97356SBlue Swirl     int64_t nb_clusters, k, k1, size;
119120d97356SBlue Swirl     int refcount;
119220d97356SBlue Swirl 
119366f82ceeSKevin Wolf     size = bdrv_getlength(bs->file);
119420d97356SBlue Swirl     nb_clusters = size_to_clusters(s, size);
119520d97356SBlue Swirl     for(k = 0; k < nb_clusters;) {
119620d97356SBlue Swirl         k1 = k;
119720d97356SBlue Swirl         refcount = get_refcount(bs, k);
119820d97356SBlue Swirl         k++;
119920d97356SBlue Swirl         while (k < nb_clusters && get_refcount(bs, k) == refcount)
120020d97356SBlue Swirl             k++;
12010bfcd599SBlue Swirl         printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
12020bfcd599SBlue Swirl                k - k1);
120320d97356SBlue Swirl     }
120420d97356SBlue Swirl }
120520d97356SBlue Swirl #endif
120620d97356SBlue Swirl 
12077c80ab3fSJes Sorensen static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
120820d97356SBlue Swirl                               int64_t pos, int size)
120920d97356SBlue Swirl {
121020d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
121120d97356SBlue Swirl     int growable = bs->growable;
121220d97356SBlue Swirl     int ret;
121320d97356SBlue Swirl 
121466f82ceeSKevin Wolf     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
121520d97356SBlue Swirl     bs->growable = 1;
12167c80ab3fSJes Sorensen     ret = bdrv_pwrite(bs, qcow2_vm_state_offset(s) + pos, buf, size);
121720d97356SBlue Swirl     bs->growable = growable;
121820d97356SBlue Swirl 
121920d97356SBlue Swirl     return ret;
122020d97356SBlue Swirl }
122120d97356SBlue Swirl 
12227c80ab3fSJes Sorensen static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
122320d97356SBlue Swirl                               int64_t pos, int size)
122420d97356SBlue Swirl {
122520d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
122620d97356SBlue Swirl     int growable = bs->growable;
122720d97356SBlue Swirl     int ret;
122820d97356SBlue Swirl 
122966f82ceeSKevin Wolf     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
123020d97356SBlue Swirl     bs->growable = 1;
12317c80ab3fSJes Sorensen     ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size);
123220d97356SBlue Swirl     bs->growable = growable;
123320d97356SBlue Swirl 
123420d97356SBlue Swirl     return ret;
123520d97356SBlue Swirl }
123620d97356SBlue Swirl 
12377c80ab3fSJes Sorensen static QEMUOptionParameter qcow2_create_options[] = {
123820d97356SBlue Swirl     {
123920d97356SBlue Swirl         .name = BLOCK_OPT_SIZE,
124020d97356SBlue Swirl         .type = OPT_SIZE,
124120d97356SBlue Swirl         .help = "Virtual disk size"
124220d97356SBlue Swirl     },
124320d97356SBlue Swirl     {
124420d97356SBlue Swirl         .name = BLOCK_OPT_BACKING_FILE,
124520d97356SBlue Swirl         .type = OPT_STRING,
124620d97356SBlue Swirl         .help = "File name of a base image"
124720d97356SBlue Swirl     },
124820d97356SBlue Swirl     {
124920d97356SBlue Swirl         .name = BLOCK_OPT_BACKING_FMT,
125020d97356SBlue Swirl         .type = OPT_STRING,
125120d97356SBlue Swirl         .help = "Image format of the base image"
125220d97356SBlue Swirl     },
125320d97356SBlue Swirl     {
125420d97356SBlue Swirl         .name = BLOCK_OPT_ENCRYPT,
125520d97356SBlue Swirl         .type = OPT_FLAG,
125620d97356SBlue Swirl         .help = "Encrypt the image"
125720d97356SBlue Swirl     },
125820d97356SBlue Swirl     {
125920d97356SBlue Swirl         .name = BLOCK_OPT_CLUSTER_SIZE,
126020d97356SBlue Swirl         .type = OPT_SIZE,
126199cce9faSKevin Wolf         .help = "qcow2 cluster size",
126299cce9faSKevin Wolf         .value = { .n = DEFAULT_CLUSTER_SIZE },
126320d97356SBlue Swirl     },
126420d97356SBlue Swirl     {
126520d97356SBlue Swirl         .name = BLOCK_OPT_PREALLOC,
126620d97356SBlue Swirl         .type = OPT_STRING,
126720d97356SBlue Swirl         .help = "Preallocation mode (allowed values: off, metadata)"
126820d97356SBlue Swirl     },
126920d97356SBlue Swirl     { NULL }
127020d97356SBlue Swirl };
127120d97356SBlue Swirl 
127220d97356SBlue Swirl static BlockDriver bdrv_qcow2 = {
127320d97356SBlue Swirl     .format_name        = "qcow2",
127420d97356SBlue Swirl     .instance_size      = sizeof(BDRVQcowState),
12757c80ab3fSJes Sorensen     .bdrv_probe         = qcow2_probe,
12767c80ab3fSJes Sorensen     .bdrv_open          = qcow2_open,
12777c80ab3fSJes Sorensen     .bdrv_close         = qcow2_close,
12787c80ab3fSJes Sorensen     .bdrv_create        = qcow2_create,
12797c80ab3fSJes Sorensen     .bdrv_is_allocated  = qcow2_is_allocated,
12807c80ab3fSJes Sorensen     .bdrv_set_key       = qcow2_set_key,
12817c80ab3fSJes Sorensen     .bdrv_make_empty    = qcow2_make_empty,
128220d97356SBlue Swirl 
128368d100e9SKevin Wolf     .bdrv_co_readv          = qcow2_co_readv,
128468d100e9SKevin Wolf     .bdrv_co_writev         = qcow2_co_writev,
1285eb489bb1SKevin Wolf     .bdrv_co_flush_to_os    = qcow2_co_flush_to_os,
1286eb489bb1SKevin Wolf     .bdrv_co_flush_to_disk  = qcow2_co_flush_to_disk,
1287419b19d9SStefan Hajnoczi 
12886db39ae2SPaolo Bonzini     .bdrv_co_discard        = qcow2_co_discard,
1289419b19d9SStefan Hajnoczi     .bdrv_truncate          = qcow2_truncate,
12907c80ab3fSJes Sorensen     .bdrv_write_compressed  = qcow2_write_compressed,
129120d97356SBlue Swirl 
129220d97356SBlue Swirl     .bdrv_snapshot_create   = qcow2_snapshot_create,
129320d97356SBlue Swirl     .bdrv_snapshot_goto     = qcow2_snapshot_goto,
129420d97356SBlue Swirl     .bdrv_snapshot_delete   = qcow2_snapshot_delete,
129520d97356SBlue Swirl     .bdrv_snapshot_list     = qcow2_snapshot_list,
129651ef6727Sedison     .bdrv_snapshot_load_tmp     = qcow2_snapshot_load_tmp,
12977c80ab3fSJes Sorensen     .bdrv_get_info      = qcow2_get_info,
129820d97356SBlue Swirl 
12997c80ab3fSJes Sorensen     .bdrv_save_vmstate    = qcow2_save_vmstate,
13007c80ab3fSJes Sorensen     .bdrv_load_vmstate    = qcow2_load_vmstate,
130120d97356SBlue Swirl 
130220d97356SBlue Swirl     .bdrv_change_backing_file   = qcow2_change_backing_file,
130320d97356SBlue Swirl 
1304*06d9260fSAnthony Liguori     .bdrv_invalidate_cache      = qcow2_invalidate_cache,
1305*06d9260fSAnthony Liguori 
13067c80ab3fSJes Sorensen     .create_options = qcow2_create_options,
13077c80ab3fSJes Sorensen     .bdrv_check = qcow2_check,
130820d97356SBlue Swirl };
130920d97356SBlue Swirl 
13105efa9d5aSAnthony Liguori static void bdrv_qcow2_init(void)
13115efa9d5aSAnthony Liguori {
13125efa9d5aSAnthony Liguori     bdrv_register(&bdrv_qcow2);
13135efa9d5aSAnthony Liguori }
13145efa9d5aSAnthony Liguori 
13155efa9d5aSAnthony Liguori block_init(bdrv_qcow2_init);
1316