diff options
Diffstat (limited to 'block-qcow2.c')
| -rw-r--r-- | block-qcow2.c | 2620 |
1 files changed, 0 insertions, 2620 deletions
diff --git a/block-qcow2.c b/block-qcow2.c deleted file mode 100644 index 5f0fbe8..0000000 --- a/block-qcow2.c +++ /dev/null @@ -1,2620 +0,0 @@ -/* - * Block driver for the QCOW version 2 format - * - * Copyright (c) 2004-2006 Fabrice Bellard - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -#include "qemu-common.h" -#include "block_int.h" -#include <zlib.h> -#include "aes.h" -#include <assert.h> - -/* - Differences with QCOW: - - - Support for multiple incremental snapshots. - - Memory management by reference counts. - - Clusters which have a reference count of one have the bit - QCOW_OFLAG_COPIED to optimize write performance. - - Size of compressed clusters is stored in sectors to reduce bit usage - in the cluster offsets. - - Support for storing additional data (such as the VM state) in the - snapshots. - - If a backing store is used, the cluster size is not constrained - (could be backported to QCOW). - - L2 tables have always a size of one cluster. -*/ - -//#define DEBUG_ALLOC -//#define DEBUG_ALLOC2 - -#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) -#define QCOW_VERSION 2 - -#define QCOW_CRYPT_NONE 0 -#define QCOW_CRYPT_AES 1 - -#define QCOW_MAX_CRYPT_CLUSTERS 32 - -/* indicate that the refcount of the referenced cluster is exactly one. */ -#define QCOW_OFLAG_COPIED (1LL << 63) -/* indicate that the cluster is compressed (they never have the copied flag) */ -#define QCOW_OFLAG_COMPRESSED (1LL << 62) - -#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ - -typedef struct QCowHeader { - uint32_t magic; - uint32_t version; - uint64_t backing_file_offset; - uint32_t backing_file_size; - uint32_t cluster_bits; - uint64_t size; /* in bytes */ - uint32_t crypt_method; - uint32_t l1_size; /* XXX: save number of clusters instead ? */ - uint64_t l1_table_offset; - uint64_t refcount_table_offset; - uint32_t refcount_table_clusters; - uint32_t nb_snapshots; - uint64_t snapshots_offset; -} QCowHeader; - -typedef struct __attribute__((packed)) QCowSnapshotHeader { - /* header is 8 byte aligned */ - uint64_t l1_table_offset; - - uint32_t l1_size; - uint16_t id_str_size; - uint16_t name_size; - - uint32_t date_sec; - uint32_t date_nsec; - - uint64_t vm_clock_nsec; - - uint32_t vm_state_size; - uint32_t extra_data_size; /* for extension */ - /* extra data follows */ - /* id_str follows */ - /* name follows */ -} QCowSnapshotHeader; - -#define L2_CACHE_SIZE 16 - -typedef struct QCowSnapshot { - uint64_t l1_table_offset; - uint32_t l1_size; - char *id_str; - char *name; - uint32_t vm_state_size; - uint32_t date_sec; - uint32_t date_nsec; - uint64_t vm_clock_nsec; -} QCowSnapshot; - -typedef struct BDRVQcowState { - BlockDriverState *hd; - int cluster_bits; - int cluster_size; - int cluster_sectors; - int l2_bits; - int l2_size; - int l1_size; - int l1_vm_state_index; - int csize_shift; - int csize_mask; - uint64_t cluster_offset_mask; - uint64_t l1_table_offset; - uint64_t *l1_table; - uint64_t *l2_cache; - uint64_t l2_cache_offsets[L2_CACHE_SIZE]; - uint32_t l2_cache_counts[L2_CACHE_SIZE]; - uint8_t *cluster_cache; - uint8_t *cluster_data; - uint64_t cluster_cache_offset; - - uint64_t *refcount_table; - uint64_t refcount_table_offset; - uint32_t refcount_table_size; - uint64_t refcount_block_cache_offset; - uint16_t *refcount_block_cache; - int64_t free_cluster_index; - int64_t free_byte_offset; - - uint32_t crypt_method; /* current crypt method, 0 if no key yet */ - uint32_t crypt_method_header; - AES_KEY aes_encrypt_key; - AES_KEY aes_decrypt_key; - uint64_t snapshots_offset; - int snapshots_size; - int nb_snapshots; - QCowSnapshot *snapshots; -} BDRVQcowState; - -static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); -static int qcow_read(BlockDriverState *bs, int64_t sector_num, - uint8_t *buf, int nb_sectors); -static int qcow_read_snapshots(BlockDriverState *bs); -static void qcow_free_snapshots(BlockDriverState *bs); -static int refcount_init(BlockDriverState *bs); -static void refcount_close(BlockDriverState *bs); -static int get_refcount(BlockDriverState *bs, int64_t cluster_index); -static int update_cluster_refcount(BlockDriverState *bs, - int64_t cluster_index, - int addend); -static void update_refcount(BlockDriverState *bs, - int64_t offset, int64_t length, - int addend); -static int64_t alloc_clusters(BlockDriverState *bs, int64_t size); -static int64_t alloc_bytes(BlockDriverState *bs, int size); -static void free_clusters(BlockDriverState *bs, - int64_t offset, int64_t size); -#ifdef DEBUG_ALLOC -static void check_refcounts(BlockDriverState *bs); -#endif - -static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) -{ - const QCowHeader *cow_header = (const void *)buf; - - if (buf_size >= sizeof(QCowHeader) && - be32_to_cpu(cow_header->magic) == QCOW_MAGIC && - be32_to_cpu(cow_header->version) == QCOW_VERSION) - return 100; - else - return 0; -} - -static int qcow_open(BlockDriverState *bs, const char *filename, int flags) -{ - BDRVQcowState *s = bs->opaque; - int len, i, shift, ret; - QCowHeader header; - - ret = bdrv_file_open(&s->hd, filename, flags); - if (ret < 0) - return ret; - if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) - goto fail; - be32_to_cpus(&header.magic); - be32_to_cpus(&header.version); - be64_to_cpus(&header.backing_file_offset); - be32_to_cpus(&header.backing_file_size); - be64_to_cpus(&header.size); - be32_to_cpus(&header.cluster_bits); - be32_to_cpus(&header.crypt_method); - be64_to_cpus(&header.l1_table_offset); - be32_to_cpus(&header.l1_size); - be64_to_cpus(&header.refcount_table_offset); - be32_to_cpus(&header.refcount_table_clusters); - be64_to_cpus(&header.snapshots_offset); - be32_to_cpus(&header.nb_snapshots); - - if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) - goto fail; - if (header.size <= 1 || - header.cluster_bits < 9 || - header.cluster_bits > 16) - goto fail; - if (header.crypt_method > QCOW_CRYPT_AES) - goto fail; - s->crypt_method_header = header.crypt_method; - if (s->crypt_method_header) - bs->encrypted = 1; - s->cluster_bits = header.cluster_bits; - s->cluster_size = 1 << s->cluster_bits; - s->cluster_sectors = 1 << (s->cluster_bits - 9); - s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ - s->l2_size = 1 << s->l2_bits; - bs->total_sectors = header.size / 512; - s->csize_shift = (62 - (s->cluster_bits - 8)); - s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; - s->cluster_offset_mask = (1LL << s->csize_shift) - 1; - s->refcount_table_offset = header.refcount_table_offset; - s->refcount_table_size = - header.refcount_table_clusters << (s->cluster_bits - 3); - - s->snapshots_offset = header.snapshots_offset; - s->nb_snapshots = header.nb_snapshots; - - /* read the level 1 table */ - s->l1_size = header.l1_size; - shift = s->cluster_bits + s->l2_bits; - s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; - /* the L1 table must contain at least enough entries to put - header.size bytes */ - if (s->l1_size < s->l1_vm_state_index) - goto fail; - s->l1_table_offset = header.l1_table_offset; - s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t)); - if (!s->l1_table) - goto fail; - if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != - s->l1_size * sizeof(uint64_t)) - goto fail; - for(i = 0;i < s->l1_size; i++) { - be64_to_cpus(&s->l1_table[i]); - } - /* alloc L2 cache */ - s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); - if (!s->l2_cache) - goto fail; - s->cluster_cache = qemu_malloc(s->cluster_size); - if (!s->cluster_cache) - goto fail; - /* one more sector for decompressed data alignment */ - s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size - + 512); - if (!s->cluster_data) - goto fail; - s->cluster_cache_offset = -1; - - if (refcount_init(bs) < 0) - goto fail; - - /* read the backing file name */ - if (header.backing_file_offset != 0) { - len = header.backing_file_size; - if (len > 1023) - len = 1023; - if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) - goto fail; - bs->backing_file[len] = '\0'; - } - if (qcow_read_snapshots(bs) < 0) - goto fail; - -#ifdef DEBUG_ALLOC - check_refcounts(bs); -#endif - return 0; - - fail: - qcow_free_snapshots(bs); - refcount_close(bs); - qemu_free(s->l1_table); - qemu_free(s->l2_cache); - qemu_free(s->cluster_cache); - qemu_free(s->cluster_data); - bdrv_delete(s->hd); - return -1; -} - -static int qcow_set_key(BlockDriverState *bs, const char *key) -{ - BDRVQcowState *s = bs->opaque; - uint8_t keybuf[16]; - int len, i; - - memset(keybuf, 0, 16); - len = strlen(key); - if (len > 16) - len = 16; - /* XXX: we could compress the chars to 7 bits to increase - entropy */ - for(i = 0;i < len;i++) { - keybuf[i] = key[i]; - } - s->crypt_method = s->crypt_method_header; - - if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) - return -1; - if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) - return -1; -#if 0 - /* test */ - { - uint8_t in[16]; - uint8_t out[16]; - uint8_t tmp[16]; - for(i=0;i<16;i++) - in[i] = i; - AES_encrypt(in, tmp, &s->aes_encrypt_key); - AES_decrypt(tmp, out, &s->aes_decrypt_key); - for(i = 0; i < 16; i++) - printf(" %02x", tmp[i]); - printf("\n"); - for(i = 0; i < 16; i++) - printf(" %02x", out[i]); - printf("\n"); - } -#endif - return 0; -} - -/* The crypt function is compatible with the linux cryptoloop - algorithm for < 4 GB images. NOTE: out_buf == in_buf is - supported */ -static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, - uint8_t *out_buf, const uint8_t *in_buf, - int nb_sectors, int enc, - const AES_KEY *key) -{ - union { - uint64_t ll[2]; - uint8_t b[16]; - } ivec; - int i; - - for(i = 0; i < nb_sectors; i++) { - ivec.ll[0] = cpu_to_le64(sector_num); - ivec.ll[1] = 0; - AES_cbc_encrypt(in_buf, out_buf, 512, key, - ivec.b, enc); - sector_num++; - in_buf += 512; - out_buf += 512; - } -} - -static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, - uint64_t cluster_offset, int n_start, int n_end) -{ - BDRVQcowState *s = bs->opaque; - int n, ret; - - n = n_end - n_start; - if (n <= 0) - return 0; - ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); - if (ret < 0) - return ret; - if (s->crypt_method) { - encrypt_sectors(s, start_sect + n_start, - s->cluster_data, - s->cluster_data, n, 1, - &s->aes_encrypt_key); - } - ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start, - s->cluster_data, n); - if (ret < 0) - return ret; - return 0; -} - -static void l2_cache_reset(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - - memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); - memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); - memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); -} - -static inline int l2_cache_new_entry(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - uint32_t min_count; - int min_index, i; - - /* find a new entry in the least used one */ - min_index = 0; - min_count = 0xffffffff; - for(i = 0; i < L2_CACHE_SIZE; i++) { - if (s->l2_cache_counts[i] < min_count) { - min_count = s->l2_cache_counts[i]; - min_index = i; - } - } - return min_index; -} - -static int64_t align_offset(int64_t offset, int n) -{ - offset = (offset + n - 1) & ~(n - 1); - return offset; -} - -static int grow_l1_table(BlockDriverState *bs, int min_size) -{ - BDRVQcowState *s = bs->opaque; - int new_l1_size, new_l1_size2, ret, i; - uint64_t *new_l1_table; - uint64_t new_l1_table_offset; - uint64_t data64; - uint32_t data32; - - new_l1_size = s->l1_size; - if (min_size <= new_l1_size) - return 0; - while (min_size > new_l1_size) { - new_l1_size = (new_l1_size * 3 + 1) / 2; - } -#ifdef DEBUG_ALLOC2 - printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size); -#endif - - new_l1_size2 = sizeof(uint64_t) * new_l1_size; - new_l1_table = qemu_mallocz(new_l1_size2); - if (!new_l1_table) - return -ENOMEM; - memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); - - /* write new table (align to cluster) */ - new_l1_table_offset = alloc_clusters(bs, new_l1_size2); - - for(i = 0; i < s->l1_size; i++) - new_l1_table[i] = cpu_to_be64(new_l1_table[i]); - ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); - if (ret != new_l1_size2) - goto fail; - for(i = 0; i < s->l1_size; i++) - new_l1_table[i] = be64_to_cpu(new_l1_table[i]); - - /* set new table */ - data64 = cpu_to_be64(new_l1_table_offset); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_table_offset), - &data64, sizeof(data64)) != sizeof(data64)) - goto fail; - data32 = cpu_to_be32(new_l1_size); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), - &data32, sizeof(data32)) != sizeof(data32)) - goto fail; - qemu_free(s->l1_table); - free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t)); - s->l1_table_offset = new_l1_table_offset; - s->l1_table = new_l1_table; - s->l1_size = new_l1_size; - return 0; - fail: - qemu_free(s->l1_table); - return -EIO; -} - -/* - * seek_l2_table - * - * seek l2_offset in the l2_cache table - * if not found, return NULL, - * if found, - * increments the l2 cache hit count of the entry, - * if counter overflow, divide by two all counters - * return the pointer to the l2 cache entry - * - */ - -static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset) -{ - int i, j; - - for(i = 0; i < L2_CACHE_SIZE; i++) { - if (l2_offset == s->l2_cache_offsets[i]) { - /* increment the hit count */ - if (++s->l2_cache_counts[i] == 0xffffffff) { - for(j = 0; j < L2_CACHE_SIZE; j++) { - s->l2_cache_counts[j] >>= 1; - } - } - return s->l2_cache + (i << s->l2_bits); - } - } - return NULL; -} - -/* - * l2_load - * - * Loads a L2 table into memory. If the table is in the cache, the cache - * is used; otherwise the L2 table is loaded from the image file. - * - * Returns a pointer to the L2 table on success, or NULL if the read from - * the image file failed. - */ - -static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset) -{ - BDRVQcowState *s = bs->opaque; - int min_index; - uint64_t *l2_table; - - /* seek if the table for the given offset is in the cache */ - - l2_table = seek_l2_table(s, l2_offset); - if (l2_table != NULL) - return l2_table; - - /* not found: load a new entry in the least used one */ - - min_index = l2_cache_new_entry(bs); - l2_table = s->l2_cache + (min_index << s->l2_bits); - if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != - s->l2_size * sizeof(uint64_t)) - return NULL; - s->l2_cache_offsets[min_index] = l2_offset; - s->l2_cache_counts[min_index] = 1; - - return l2_table; -} - -/* - * l2_allocate - * - * Allocate a new l2 entry in the file. If l1_index points to an already - * used entry in the L2 table (i.e. we are doing a copy on write for the L2 - * table) copy the contents of the old L2 table into the newly allocated one. - * Otherwise the new table is initialized with zeros. - * - */ - -static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) -{ - BDRVQcowState *s = bs->opaque; - int min_index; - uint64_t old_l2_offset, tmp; - uint64_t *l2_table, l2_offset; - - old_l2_offset = s->l1_table[l1_index]; - - /* allocate a new l2 entry */ - - l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t)); - - /* update the L1 entry */ - - s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; - - tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); - if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), - &tmp, sizeof(tmp)) != sizeof(tmp)) - return NULL; - - /* allocate a new entry in the l2 cache */ - - min_index = l2_cache_new_entry(bs); - l2_table = s->l2_cache + (min_index << s->l2_bits); - - if (old_l2_offset == 0) { - /* if there was no old l2 table, clear the new table */ - memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); - } else { - /* if there was an old l2 table, read it from the disk */ - if (bdrv_pread(s->hd, old_l2_offset, - l2_table, s->l2_size * sizeof(uint64_t)) != - s->l2_size * sizeof(uint64_t)) - return NULL; - } - /* write the l2 table to the file */ - if (bdrv_pwrite(s->hd, l2_offset, - l2_table, s->l2_size * sizeof(uint64_t)) != - s->l2_size * sizeof(uint64_t)) - return NULL; - - /* update the l2 cache entry */ - - s->l2_cache_offsets[min_index] = l2_offset; - s->l2_cache_counts[min_index] = 1; - - return l2_table; -} - -/* - * get_cluster_offset - * - * For a given offset of the disk image, return cluster offset in - * qcow2 file. - * - * on entry, *num is the number of contiguous clusters we'd like to - * access following offset. - * - * on exit, *num is the number of contiguous clusters we can read. - * - * Return 1, if the offset is found - * Return 0, otherwise. - * - */ - -static uint64_t get_cluster_offset(BlockDriverState *bs, - uint64_t offset, int *num) -{ - BDRVQcowState *s = bs->opaque; - int l1_index, l2_index; - uint64_t l2_offset, *l2_table, cluster_offset, next; - int l1_bits; - int index_in_cluster, nb_available, nb_needed; - - index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); - nb_needed = *num + index_in_cluster; - - l1_bits = s->l2_bits + s->cluster_bits; - - /* compute how many bytes there are between the offset and - * and the end of the l1 entry - */ - - nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); - - /* compute the number of available sectors */ - - nb_available = (nb_available >> 9) + index_in_cluster; - - cluster_offset = 0; - - /* seek the the l2 offset in the l1 table */ - - l1_index = offset >> l1_bits; - if (l1_index >= s->l1_size) - goto out; - - l2_offset = s->l1_table[l1_index]; - - /* seek the l2 table of the given l2 offset */ - - if (!l2_offset) - goto out; - - /* load the l2 table in memory */ - - l2_offset &= ~QCOW_OFLAG_COPIED; - l2_table = l2_load(bs, l2_offset); - if (l2_table == NULL) - return 0; - - /* find the cluster offset for the given disk offset */ - - l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); - cluster_offset = be64_to_cpu(l2_table[l2_index]); - nb_available = s->cluster_sectors; - l2_index++; - - if (!cluster_offset) { - - /* how many empty clusters ? */ - - while (nb_available < nb_needed && !l2_table[l2_index]) { - l2_index++; - nb_available += s->cluster_sectors; - } - } else { - - /* how many allocated clusters ? */ - - cluster_offset &= ~QCOW_OFLAG_COPIED; - while (nb_available < nb_needed) { - next = be64_to_cpu(l2_table[l2_index]) & ~QCOW_OFLAG_COPIED; - if (next != cluster_offset + (nb_available << 9)) - break; - l2_index++; - nb_available += s->cluster_sectors; - } - } - -out: - if (nb_available > nb_needed) - nb_available = nb_needed; - - *num = nb_available - index_in_cluster; - - return cluster_offset; -} - -/* - * free_any_clusters - * - * free clusters according to its type: compressed or not - * - */ - -static void free_any_clusters(BlockDriverState *bs, - uint64_t cluster_offset, int nb_clusters) -{ - BDRVQcowState *s = bs->opaque; - - /* free the cluster */ - - if (cluster_offset & QCOW_OFLAG_COMPRESSED) { - int nb_csectors; - nb_csectors = ((cluster_offset >> s->csize_shift) & - s->csize_mask) + 1; - free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511, - nb_csectors * 512); - return; - } - - free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); - - return; -} - -/* - * get_cluster_table - * - * for a given disk offset, load (and allocate if needed) - * the l2 table. - * - * the l2 table offset in the qcow2 file and the cluster index - * in the l2 table are given to the caller. - * - */ - -static int get_cluster_table(BlockDriverState *bs, uint64_t offset, - uint64_t **new_l2_table, - uint64_t *new_l2_offset, - int *new_l2_index) -{ - BDRVQcowState *s = bs->opaque; - int l1_index, l2_index, ret; - uint64_t l2_offset, *l2_table; - - /* seek the the l2 offset in the l1 table */ - - l1_index = offset >> (s->l2_bits + s->cluster_bits); - if (l1_index >= s->l1_size) { - ret = grow_l1_table(bs, l1_index + 1); - if (ret < 0) - return 0; - } - l2_offset = s->l1_table[l1_index]; - - /* seek the l2 table of the given l2 offset */ - - if (l2_offset & QCOW_OFLAG_COPIED) { - /* load the l2 table in memory */ - l2_offset &= ~QCOW_OFLAG_COPIED; - l2_table = l2_load(bs, l2_offset); - if (l2_table == NULL) - return 0; - } else { - if (l2_offset) - free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t)); - l2_table = l2_allocate(bs, l1_index); - if (l2_table == NULL) - return 0; - l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; - } - - /* find the cluster offset for the given disk offset */ - - l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); - - *new_l2_table = l2_table; - *new_l2_offset = l2_offset; - *new_l2_index = l2_index; - - return 1; -} - -/* - * alloc_compressed_cluster_offset - * - * For a given offset of the disk image, return cluster offset in - * qcow2 file. - * - * If the offset is not found, allocate a new compressed cluster. - * - * Return the cluster offset if successful, - * Return 0, otherwise. - * - */ - -static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs, - uint64_t offset, - int compressed_size) -{ - BDRVQcowState *s = bs->opaque; - int l2_index, ret; - uint64_t l2_offset, *l2_table, cluster_offset; - int nb_csectors; - - ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); - if (ret == 0) - return 0; - - cluster_offset = be64_to_cpu(l2_table[l2_index]); - if (cluster_offset & QCOW_OFLAG_COPIED) - return cluster_offset & ~QCOW_OFLAG_COPIED; - - if (cluster_offset) - free_any_clusters(bs, cluster_offset, 1); - - cluster_offset = alloc_bytes(bs, compressed_size); - nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - - (cluster_offset >> 9); - - cluster_offset |= QCOW_OFLAG_COMPRESSED | - ((uint64_t)nb_csectors << s->csize_shift); - - /* update L2 table */ - - /* compressed clusters never have the copied flag */ - - l2_table[l2_index] = cpu_to_be64(cluster_offset); - if (bdrv_pwrite(s->hd, - l2_offset + l2_index * sizeof(uint64_t), - l2_table + l2_index, - sizeof(uint64_t)) != sizeof(uint64_t)) - return 0; - - return cluster_offset; -} - -/* - * alloc_cluster_offset - * - * For a given offset of the disk image, return cluster offset in - * qcow2 file. - * - * If the offset is not found, allocate a new cluster. - * - * Return the cluster offset if successful, - * Return 0, otherwise. - * - */ - -static uint64_t alloc_cluster_offset(BlockDriverState *bs, - uint64_t offset, - int n_start, int n_end, - int *num) -{ - BDRVQcowState *s = bs->opaque; - int l2_index, ret; - uint64_t l2_offset, *l2_table, cluster_offset; - int nb_available, nb_clusters, i, j; - uint64_t start_sect, current; - - ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); - if (ret == 0) - return 0; - - nb_clusters = ((n_end << 9) + s->cluster_size - 1) >> - s->cluster_bits; - if (nb_clusters > s->l2_size - l2_index) - nb_clusters = s->l2_size - l2_index; - - cluster_offset = be64_to_cpu(l2_table[l2_index]); - - /* We keep all QCOW_OFLAG_COPIED clusters */ - - if (cluster_offset & QCOW_OFLAG_COPIED) { - - for (i = 1; i < nb_clusters; i++) { - current = be64_to_cpu(l2_table[l2_index + i]); - if (cluster_offset + (i << s->cluster_bits) != current) - break; - } - nb_clusters = i; - - nb_available = nb_clusters << (s->cluster_bits - 9); - if (nb_available > n_end) - nb_available = n_end; - - cluster_offset &= ~QCOW_OFLAG_COPIED; - - goto out; - } - - /* for the moment, multiple compressed clusters are not managed */ - - if (cluster_offset & QCOW_OFLAG_COMPRESSED) - nb_clusters = 1; - - /* how many available clusters ? */ - - i = 0; - while (i < nb_clusters) { - - i++; - - if (!cluster_offset) { - - /* how many free clusters ? */ - - while (i < nb_clusters) { - cluster_offset = l2_table[l2_index + i]; - if (cluster_offset != 0) - break; - i++; - } - - if ((cluster_offset & QCOW_OFLAG_COPIED) || - (cluster_offset & QCOW_OFLAG_COMPRESSED)) - break; - - } else { - - /* how many contiguous clusters ? */ - - j = 1; - current = 0; - while (i < nb_clusters) { - current = be64_to_cpu(l2_table[l2_index + i]); - if (cluster_offset + (j << s->cluster_bits) != current) - break; - - i++; - j++; - } - - free_any_clusters(bs, cluster_offset, j); - if (current) - break; - cluster_offset = current; - } - } - nb_clusters = i; - - /* allocate a new cluster */ - - cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); - - /* we must initialize the cluster content which won't be - written */ - - nb_available = nb_clusters << (s->cluster_bits - 9); - if (nb_available > n_end) - nb_available = n_end; - - /* copy content of unmodified sectors */ - - start_sect = (offset & ~(s->cluster_size - 1)) >> 9; - if (n_start) { - ret = copy_sectors(bs, start_sect, cluster_offset, 0, n_start); - if (ret < 0) - return 0; - } - - if (nb_available & (s->cluster_sectors - 1)) { - uint64_t end = nb_available & ~(uint64_t)(s->cluster_sectors - 1); - ret = copy_sectors(bs, start_sect + end, - cluster_offset + (end << 9), - nb_available - end, - s->cluster_sectors); - if (ret < 0) - return 0; - } - - /* update L2 table */ - - for (i = 0; i < nb_clusters; i++) - l2_table[l2_index + i] = cpu_to_be64((cluster_offset + - (i << s->cluster_bits)) | - QCOW_OFLAG_COPIED); - - if (bdrv_pwrite(s->hd, - l2_offset + l2_index * sizeof(uint64_t), - l2_table + l2_index, - nb_clusters * sizeof(uint64_t)) != - nb_clusters * sizeof(uint64_t)) - return 0; - -out: - *num = nb_available - n_start; - - return cluster_offset; -} - -static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, int *pnum) -{ - uint64_t cluster_offset; - - *pnum = nb_sectors; - cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum); - - return (cluster_offset != 0); -} - -static int decompress_buffer(uint8_t *out_buf, int out_buf_size, - const uint8_t *buf, int buf_size) -{ - z_stream strm1, *strm = &strm1; - int ret, out_len; - - memset(strm, 0, sizeof(*strm)); - - strm->next_in = (uint8_t *)buf; - strm->avail_in = buf_size; - strm->next_out = out_buf; - strm->avail_out = out_buf_size; - - ret = inflateInit2(strm, -12); - if (ret != Z_OK) - return -1; - ret = inflate(strm, Z_FINISH); - out_len = strm->next_out - out_buf; - if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || - out_len != out_buf_size) { - inflateEnd(strm); - return -1; - } - inflateEnd(strm); - return 0; -} - -static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) -{ - int ret, csize, nb_csectors, sector_offset; - uint64_t coffset; - - coffset = cluster_offset & s->cluster_offset_mask; - if (s->cluster_cache_offset != coffset) { - nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1; - sector_offset = coffset & 511; - csize = nb_csectors * 512 - sector_offset; - ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors); - if (ret < 0) { - return -1; - } - if (decompress_buffer(s->cluster_cache, s->cluster_size, - s->cluster_data + sector_offset, csize) < 0) { - return -1; - } - s->cluster_cache_offset = coffset; - } - return 0; -} - -/* handle reading after the end of the backing file */ -static int backing_read1(BlockDriverState *bs, - int64_t sector_num, uint8_t *buf, int nb_sectors) -{ - int n1; - if ((sector_num + nb_sectors) <= bs->total_sectors) - return nb_sectors; - if (sector_num >= bs->total_sectors) - n1 = 0; - else - n1 = bs->total_sectors - sector_num; - memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); - return n1; -} - -static int qcow_read(BlockDriverState *bs, int64_t sector_num, - uint8_t *buf, int nb_sectors) -{ - BDRVQcowState *s = bs->opaque; - int ret, index_in_cluster, n, n1; - uint64_t cluster_offset; - - while (nb_sectors > 0) { - n = nb_sectors; - cluster_offset = get_cluster_offset(bs, sector_num << 9, &n); - index_in_cluster = sector_num & (s->cluster_sectors - 1); - if (!cluster_offset) { - if (bs->backing_hd) { - /* read from the base image */ - n1 = backing_read1(bs->backing_hd, sector_num, buf, n); - if (n1 > 0) { - ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); - if (ret < 0) - return -1; - } - } else { - memset(buf, 0, 512 * n); - } - } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { - if (decompress_cluster(s, cluster_offset) < 0) - return -1; - memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); - } else { - ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); - if (ret != n * 512) - return -1; - if (s->crypt_method) { - encrypt_sectors(s, sector_num, buf, buf, n, 0, - &s->aes_decrypt_key); - } - } - nb_sectors -= n; - sector_num += n; - buf += n * 512; - } - return 0; -} - -static int qcow_write(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) -{ - BDRVQcowState *s = bs->opaque; - int ret, index_in_cluster, n; - uint64_t cluster_offset; - int n_end; - - while (nb_sectors > 0) { - index_in_cluster = sector_num & (s->cluster_sectors - 1); - n_end = index_in_cluster + nb_sectors; - if (s->crypt_method && - n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) - n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; - cluster_offset = alloc_cluster_offset(bs, sector_num << 9, - index_in_cluster, - n_end, &n); - if (!cluster_offset) - return -1; - if (s->crypt_method) { - encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1, - &s->aes_encrypt_key); - ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, - s->cluster_data, n * 512); - } else { - ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); - } - if (ret != n * 512) - return -1; - nb_sectors -= n; - sector_num += n; - buf += n * 512; - } - s->cluster_cache_offset = -1; /* disable compressed cache */ - return 0; -} - -typedef struct QCowAIOCB { - BlockDriverAIOCB common; - int64_t sector_num; - uint8_t *buf; - int nb_sectors; - int n; - uint64_t cluster_offset; - uint8_t *cluster_data; - BlockDriverAIOCB *hd_aiocb; -} QCowAIOCB; - -static void qcow_aio_read_cb(void *opaque, int ret) -{ - QCowAIOCB *acb = opaque; - BlockDriverState *bs = acb->common.bs; - BDRVQcowState *s = bs->opaque; - int index_in_cluster, n1; - - acb->hd_aiocb = NULL; - if (ret < 0) { - fail: - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); - return; - } - - redo: - /* post process the read buffer */ - if (!acb->cluster_offset) { - /* nothing to do */ - } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { - /* nothing to do */ - } else { - if (s->crypt_method) { - encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, - acb->n, 0, - &s->aes_decrypt_key); - } - } - - acb->nb_sectors -= acb->n; - acb->sector_num += acb->n; - acb->buf += acb->n * 512; - - if (acb->nb_sectors == 0) { - /* request completed */ - acb->common.cb(acb->common.opaque, 0); - qemu_aio_release(acb); - return; - } - - /* prepare next AIO request */ - acb->n = acb->nb_sectors; - acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n); - index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); - - if (!acb->cluster_offset) { - if (bs->backing_hd) { - /* read from the base image */ - n1 = backing_read1(bs->backing_hd, acb->sector_num, - acb->buf, acb->n); - if (n1 > 0) { - acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num, - acb->buf, acb->n, qcow_aio_read_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; - } else { - goto redo; - } - } else { - /* Note: in this case, no need to wait */ - memset(acb->buf, 0, 512 * acb->n); - goto redo; - } - } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { - /* add AIO support for compressed blocks ? */ - if (decompress_cluster(s, acb->cluster_offset) < 0) - goto fail; - memcpy(acb->buf, - s->cluster_cache + index_in_cluster * 512, 512 * acb->n); - goto redo; - } else { - if ((acb->cluster_offset & 511) != 0) { - ret = -EIO; - goto fail; - } - acb->hd_aiocb = bdrv_aio_read(s->hd, - (acb->cluster_offset >> 9) + index_in_cluster, - acb->buf, acb->n, qcow_aio_read_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; - } -} - -static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, - int64_t sector_num, uint8_t *buf, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - QCowAIOCB *acb; - - acb = qemu_aio_get(bs, cb, opaque); - if (!acb) - return NULL; - acb->hd_aiocb = NULL; - acb->sector_num = sector_num; - acb->buf = buf; - acb->nb_sectors = nb_sectors; - acb->n = 0; - acb->cluster_offset = 0; - return acb; -} - -static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs, - int64_t sector_num, uint8_t *buf, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - QCowAIOCB *acb; - - acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque); - if (!acb) - return NULL; - - qcow_aio_read_cb(acb, 0); - return &acb->common; -} - -static void qcow_aio_write_cb(void *opaque, int ret) -{ - QCowAIOCB *acb = opaque; - BlockDriverState *bs = acb->common.bs; - BDRVQcowState *s = bs->opaque; - int index_in_cluster; - uint64_t cluster_offset; - const uint8_t *src_buf; - int n_end; - - acb->hd_aiocb = NULL; - - if (ret < 0) { - fail: - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); - return; - } - - acb->nb_sectors -= acb->n; - acb->sector_num += acb->n; - acb->buf += acb->n * 512; - - if (acb->nb_sectors == 0) { - /* request completed */ - acb->common.cb(acb->common.opaque, 0); - qemu_aio_release(acb); - return; - } - - index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); - n_end = index_in_cluster + acb->nb_sectors; - if (s->crypt_method && - n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) - n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; - - cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, - index_in_cluster, - n_end, &acb->n); - if (!cluster_offset || (cluster_offset & 511) != 0) { - ret = -EIO; - goto fail; - } - if (s->crypt_method) { - if (!acb->cluster_data) { - acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * - s->cluster_size); - if (!acb->cluster_data) { - ret = -ENOMEM; - goto fail; - } - } - encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, - acb->n, 1, &s->aes_encrypt_key); - src_buf = acb->cluster_data; - } else { - src_buf = acb->buf; - } - acb->hd_aiocb = bdrv_aio_write(s->hd, - (cluster_offset >> 9) + index_in_cluster, - src_buf, acb->n, - qcow_aio_write_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; -} - -static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs, - int64_t sector_num, const uint8_t *buf, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - BDRVQcowState *s = bs->opaque; - QCowAIOCB *acb; - - s->cluster_cache_offset = -1; /* disable compressed cache */ - - acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque); - if (!acb) - return NULL; - - qcow_aio_write_cb(acb, 0); - return &acb->common; -} - -static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) -{ - QCowAIOCB *acb = (QCowAIOCB *)blockacb; - if (acb->hd_aiocb) - bdrv_aio_cancel(acb->hd_aiocb); - qemu_aio_release(acb); -} - -static void qcow_close(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - qemu_free(s->l1_table); - qemu_free(s->l2_cache); - qemu_free(s->cluster_cache); - qemu_free(s->cluster_data); - refcount_close(bs); - bdrv_delete(s->hd); -} - -/* XXX: use std qcow open function ? */ -typedef struct QCowCreateState { - int cluster_size; - int cluster_bits; - uint16_t *refcount_block; - uint64_t *refcount_table; - int64_t l1_table_offset; - int64_t refcount_table_offset; - int64_t refcount_block_offset; -} QCowCreateState; - -static void create_refcount_update(QCowCreateState *s, - int64_t offset, int64_t size) -{ - int refcount; - int64_t start, last, cluster_offset; - uint16_t *p; - - start = offset & ~(s->cluster_size - 1); - last = (offset + size - 1) & ~(s->cluster_size - 1); - for(cluster_offset = start; cluster_offset <= last; - cluster_offset += s->cluster_size) { - p = &s->refcount_block[cluster_offset >> s->cluster_bits]; - refcount = be16_to_cpu(*p); - refcount++; - *p = cpu_to_be16(refcount); - } -} - -static int qcow_create(const char *filename, int64_t total_size, - const char *backing_file, int flags) -{ - int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; - QCowHeader header; - uint64_t tmp, offset; - QCowCreateState s1, *s = &s1; - - memset(s, 0, sizeof(*s)); - - fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); - if (fd < 0) - return -1; - memset(&header, 0, sizeof(header)); - header.magic = cpu_to_be32(QCOW_MAGIC); - header.version = cpu_to_be32(QCOW_VERSION); - header.size = cpu_to_be64(total_size * 512); - header_size = sizeof(header); - backing_filename_len = 0; - if (backing_file) { - header.backing_file_offset = cpu_to_be64(header_size); - backing_filename_len = strlen(backing_file); - header.backing_file_size = cpu_to_be32(backing_filename_len); - header_size += backing_filename_len; - } - s->cluster_bits = 12; /* 4 KB clusters */ - s->cluster_size = 1 << s->cluster_bits; - header.cluster_bits = cpu_to_be32(s->cluster_bits); - header_size = (header_size + 7) & ~7; - if (flags & BLOCK_FLAG_ENCRYPT) { - header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); - } else { - header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); - } - l2_bits = s->cluster_bits - 3; - shift = s->cluster_bits + l2_bits; - l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); - offset = align_offset(header_size, s->cluster_size); - s->l1_table_offset = offset; - header.l1_table_offset = cpu_to_be64(s->l1_table_offset); - header.l1_size = cpu_to_be32(l1_size); - offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); - - s->refcount_table = qemu_mallocz(s->cluster_size); - if (!s->refcount_table) - goto fail; - s->refcount_block = qemu_mallocz(s->cluster_size); - if (!s->refcount_block) - goto fail; - - s->refcount_table_offset = offset; - header.refcount_table_offset = cpu_to_be64(offset); - header.refcount_table_clusters = cpu_to_be32(1); - offset += s->cluster_size; - - s->refcount_table[0] = cpu_to_be64(offset); - s->refcount_block_offset = offset; - offset += s->cluster_size; - - /* update refcounts */ - create_refcount_update(s, 0, header_size); - create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t)); - create_refcount_update(s, s->refcount_table_offset, s->cluster_size); - create_refcount_update(s, s->refcount_block_offset, s->cluster_size); - - /* write all the data */ - write(fd, &header, sizeof(header)); - if (backing_file) { - write(fd, backing_file, backing_filename_len); - } - lseek(fd, s->l1_table_offset, SEEK_SET); - tmp = 0; - for(i = 0;i < l1_size; i++) { - write(fd, &tmp, sizeof(tmp)); - } - lseek(fd, s->refcount_table_offset, SEEK_SET); - write(fd, s->refcount_table, s->cluster_size); - - lseek(fd, s->refcount_block_offset, SEEK_SET); - write(fd, s->refcount_block, s->cluster_size); - - qemu_free(s->refcount_table); - qemu_free(s->refcount_block); - close(fd); - return 0; - fail: - qemu_free(s->refcount_table); - qemu_free(s->refcount_block); - close(fd); - return -ENOMEM; -} - -static int qcow_make_empty(BlockDriverState *bs) -{ -#if 0 - /* XXX: not correct */ - BDRVQcowState *s = bs->opaque; - uint32_t l1_length = s->l1_size * sizeof(uint64_t); - int ret; - - memset(s->l1_table, 0, l1_length); - if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) - return -1; - ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); - if (ret < 0) - return ret; - - l2_cache_reset(bs); -#endif - return 0; -} - -/* XXX: put compressed sectors first, then all the cluster aligned - tables to avoid losing bytes in alignment */ -static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) -{ - BDRVQcowState *s = bs->opaque; - z_stream strm; - int ret, out_len; - uint8_t *out_buf; - uint64_t cluster_offset; - - if (nb_sectors == 0) { - /* align end of file to a sector boundary to ease reading with - sector based I/Os */ - cluster_offset = bdrv_getlength(s->hd); - cluster_offset = (cluster_offset + 511) & ~511; - bdrv_truncate(s->hd, cluster_offset); - return 0; - } - - if (nb_sectors != s->cluster_sectors) - return -EINVAL; - - out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); - if (!out_buf) - return -ENOMEM; - - /* best compression, small window, no zlib header */ - memset(&strm, 0, sizeof(strm)); - ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, - Z_DEFLATED, -12, - 9, Z_DEFAULT_STRATEGY); - if (ret != 0) { - qemu_free(out_buf); - return -1; - } - - strm.avail_in = s->cluster_size; - strm.next_in = (uint8_t *)buf; - strm.avail_out = s->cluster_size; - strm.next_out = out_buf; - - ret = deflate(&strm, Z_FINISH); - if (ret != Z_STREAM_END && ret != Z_OK) { - qemu_free(out_buf); - deflateEnd(&strm); - return -1; - } - out_len = strm.next_out - out_buf; - - deflateEnd(&strm); - - if (ret != Z_STREAM_END || out_len >= s->cluster_size) { - /* could not compress: write normal cluster */ - qcow_write(bs, sector_num, buf, s->cluster_sectors); - } else { - cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9, - out_len); - if (!cluster_offset) - return -1; - cluster_offset &= s->cluster_offset_mask; - if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) { - qemu_free(out_buf); - return -1; - } - } - - qemu_free(out_buf); - return 0; -} - -static void qcow_flush(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - bdrv_flush(s->hd); -} - -static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) -{ - BDRVQcowState *s = bs->opaque; - bdi->cluster_size = s->cluster_size; - bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << - (s->cluster_bits + s->l2_bits); - return 0; -} - -/*********************************************************/ -/* snapshot support */ - -/* update the refcounts of snapshots and the copied flag */ -static int update_snapshot_refcount(BlockDriverState *bs, - int64_t l1_table_offset, - int l1_size, - int addend) -{ - BDRVQcowState *s = bs->opaque; - uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; - int64_t old_offset, old_l2_offset; - int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount; - - l2_cache_reset(bs); - - l2_table = NULL; - l1_table = NULL; - l1_size2 = l1_size * sizeof(uint64_t); - l1_allocated = 0; - if (l1_table_offset != s->l1_table_offset) { - l1_table = qemu_malloc(l1_size2); - if (!l1_table) - goto fail; - l1_allocated = 1; - if (bdrv_pread(s->hd, l1_table_offset, - l1_table, l1_size2) != l1_size2) - goto fail; - for(i = 0;i < l1_size; i++) - be64_to_cpus(&l1_table[i]); - } else { - assert(l1_size == s->l1_size); - l1_table = s->l1_table; - l1_allocated = 0; - } - - l2_size = s->l2_size * sizeof(uint64_t); - l2_table = qemu_malloc(l2_size); - if (!l2_table) - goto fail; - l1_modified = 0; - for(i = 0; i < l1_size; i++) { - l2_offset = l1_table[i]; - if (l2_offset) { - old_l2_offset = l2_offset; - l2_offset &= ~QCOW_OFLAG_COPIED; - l2_modified = 0; - if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) - goto fail; - for(j = 0; j < s->l2_size; j++) { - offset = be64_to_cpu(l2_table[j]); - if (offset != 0) { - old_offset = offset; - offset &= ~QCOW_OFLAG_COPIED; - if (offset & QCOW_OFLAG_COMPRESSED) { - nb_csectors = ((offset >> s->csize_shift) & - s->csize_mask) + 1; - if (addend != 0) - update_refcount(bs, (offset & s->cluster_offset_mask) & ~511, - nb_csectors * 512, addend); - /* compressed clusters are never modified */ - refcount = 2; - } else { - if (addend != 0) { - refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); - } else { - refcount = get_refcount(bs, offset >> s->cluster_bits); - } - } - - if (refcount == 1) { - offset |= QCOW_OFLAG_COPIED; - } - if (offset != old_offset) { - l2_table[j] = cpu_to_be64(offset); - l2_modified = 1; - } - } - } - if (l2_modified) { - if (bdrv_pwrite(s->hd, - l2_offset, l2_table, l2_size) != l2_size) - goto fail; - } - - if (addend != 0) { - refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); - } else { - refcount = get_refcount(bs, l2_offset >> s->cluster_bits); - } - if (refcount == 1) { - l2_offset |= QCOW_OFLAG_COPIED; - } - if (l2_offset != old_l2_offset) { - l1_table[i] = l2_offset; - l1_modified = 1; - } - } - } - if (l1_modified) { - for(i = 0; i < l1_size; i++) - cpu_to_be64s(&l1_table[i]); - if (bdrv_pwrite(s->hd, l1_table_offset, l1_table, - l1_size2) != l1_size2) - goto fail; - for(i = 0; i < l1_size; i++) - be64_to_cpus(&l1_table[i]); - } - if (l1_allocated) - qemu_free(l1_table); - qemu_free(l2_table); - return 0; - fail: - if (l1_allocated) - qemu_free(l1_table); - qemu_free(l2_table); - return -EIO; -} - -static void qcow_free_snapshots(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - int i; - - for(i = 0; i < s->nb_snapshots; i++) { - qemu_free(s->snapshots[i].name); - qemu_free(s->snapshots[i].id_str); - } - qemu_free(s->snapshots); - s->snapshots = NULL; - s->nb_snapshots = 0; -} - -static int qcow_read_snapshots(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshotHeader h; - QCowSnapshot *sn; - int i, id_str_size, name_size; - int64_t offset; - uint32_t extra_data_size; - - offset = s->snapshots_offset; - s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot)); - if (!s->snapshots) - goto fail; - for(i = 0; i < s->nb_snapshots; i++) { - offset = align_offset(offset, 8); - if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) - goto fail; - offset += sizeof(h); - sn = s->snapshots + i; - sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); - sn->l1_size = be32_to_cpu(h.l1_size); - sn->vm_state_size = be32_to_cpu(h.vm_state_size); - sn->date_sec = be32_to_cpu(h.date_sec); - sn->date_nsec = be32_to_cpu(h.date_nsec); - sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); - extra_data_size = be32_to_cpu(h.extra_data_size); - - id_str_size = be16_to_cpu(h.id_str_size); - name_size = be16_to_cpu(h.name_size); - - offset += extra_data_size; - - sn->id_str = qemu_malloc(id_str_size + 1); - if (!sn->id_str) - goto fail; - if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size) - goto fail; - offset += id_str_size; - sn->id_str[id_str_size] = '\0'; - - sn->name = qemu_malloc(name_size + 1); - if (!sn->name) - goto fail; - if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size) - goto fail; - offset += name_size; - sn->name[name_size] = '\0'; - } - s->snapshots_size = offset - s->snapshots_offset; - return 0; - fail: - qcow_free_snapshots(bs); - return -1; -} - -/* add at the end of the file a new list of snapshots */ -static int qcow_write_snapshots(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshot *sn; - QCowSnapshotHeader h; - int i, name_size, id_str_size, snapshots_size; - uint64_t data64; - uint32_t data32; - int64_t offset, snapshots_offset; - - /* compute the size of the snapshots */ - offset = 0; - for(i = 0; i < s->nb_snapshots; i++) { - sn = s->snapshots + i; - offset = align_offset(offset, 8); - offset += sizeof(h); - offset += strlen(sn->id_str); - offset += strlen(sn->name); - } - snapshots_size = offset; - - snapshots_offset = alloc_clusters(bs, snapshots_size); - offset = snapshots_offset; - - for(i = 0; i < s->nb_snapshots; i++) { - sn = s->snapshots + i; - memset(&h, 0, sizeof(h)); - h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); - h.l1_size = cpu_to_be32(sn->l1_size); - h.vm_state_size = cpu_to_be32(sn->vm_state_size); - h.date_sec = cpu_to_be32(sn->date_sec); - h.date_nsec = cpu_to_be32(sn->date_nsec); - h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); - - id_str_size = strlen(sn->id_str); - name_size = strlen(sn->name); - h.id_str_size = cpu_to_be16(id_str_size); - h.name_size = cpu_to_be16(name_size); - offset = align_offset(offset, 8); - if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) - goto fail; - offset += sizeof(h); - if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size) - goto fail; - offset += id_str_size; - if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size) - goto fail; - offset += name_size; - } - - /* update the various header fields */ - data64 = cpu_to_be64(snapshots_offset); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset), - &data64, sizeof(data64)) != sizeof(data64)) - goto fail; - data32 = cpu_to_be32(s->nb_snapshots); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots), - &data32, sizeof(data32)) != sizeof(data32)) - goto fail; - - /* free the old snapshot table */ - free_clusters(bs, s->snapshots_offset, s->snapshots_size); - s->snapshots_offset = snapshots_offset; - s->snapshots_size = snapshots_size; - return 0; - fail: - return -1; -} - -static void find_new_snapshot_id(BlockDriverState *bs, - char *id_str, int id_str_size) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshot *sn; - int i, id, id_max = 0; - - for(i = 0; i < s->nb_snapshots; i++) { - sn = s->snapshots + i; - id = strtoul(sn->id_str, NULL, 10); - if (id > id_max) - id_max = id; - } - snprintf(id_str, id_str_size, "%d", id_max + 1); -} - -static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) -{ - BDRVQcowState *s = bs->opaque; - int i; - - for(i = 0; i < s->nb_snapshots; i++) { - if (!strcmp(s->snapshots[i].id_str, id_str)) - return i; - } - return -1; -} - -static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) -{ - BDRVQcowState *s = bs->opaque; - int i, ret; - - ret = find_snapshot_by_id(bs, name); - if (ret >= 0) - return ret; - for(i = 0; i < s->nb_snapshots; i++) { - if (!strcmp(s->snapshots[i].name, name)) - return i; - } - return -1; -} - -/* if no id is provided, a new one is constructed */ -static int qcow_snapshot_create(BlockDriverState *bs, - QEMUSnapshotInfo *sn_info) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshot *snapshots1, sn1, *sn = &sn1; - int i, ret; - uint64_t *l1_table = NULL; - - memset(sn, 0, sizeof(*sn)); - - if (sn_info->id_str[0] == '\0') { - /* compute a new id */ - find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str)); - } - - /* check that the ID is unique */ - if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) - return -ENOENT; - - sn->id_str = qemu_strdup(sn_info->id_str); - if (!sn->id_str) - goto fail; - sn->name = qemu_strdup(sn_info->name); - if (!sn->name) - goto fail; - sn->vm_state_size = sn_info->vm_state_size; - sn->date_sec = sn_info->date_sec; - sn->date_nsec = sn_info->date_nsec; - sn->vm_clock_nsec = sn_info->vm_clock_nsec; - - ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1); - if (ret < 0) - goto fail; - - /* create the L1 table of the snapshot */ - sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t)); - sn->l1_size = s->l1_size; - - l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t)); - if (!l1_table) - goto fail; - for(i = 0; i < s->l1_size; i++) { - l1_table[i] = cpu_to_be64(s->l1_table[i]); - } - if (bdrv_pwrite(s->hd, sn->l1_table_offset, - l1_table, s->l1_size * sizeof(uint64_t)) != - (s->l1_size * sizeof(uint64_t))) - goto fail; - qemu_free(l1_table); - l1_table = NULL; - - snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); - if (!snapshots1) - goto fail; - memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot)); - s->snapshots = snapshots1; - s->snapshots[s->nb_snapshots++] = *sn; - - if (qcow_write_snapshots(bs) < 0) - goto fail; -#ifdef DEBUG_ALLOC - check_refcounts(bs); -#endif - return 0; - fail: - qemu_free(sn->name); - qemu_free(l1_table); - return -1; -} - -/* copy the snapshot 'snapshot_name' into the current disk image */ -static int qcow_snapshot_goto(BlockDriverState *bs, - const char *snapshot_id) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshot *sn; - int i, snapshot_index, l1_size2; - - snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); - if (snapshot_index < 0) - return -ENOENT; - sn = &s->snapshots[snapshot_index]; - - if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) - goto fail; - - if (grow_l1_table(bs, sn->l1_size) < 0) - goto fail; - - s->l1_size = sn->l1_size; - l1_size2 = s->l1_size * sizeof(uint64_t); - /* copy the snapshot l1 table to the current l1 table */ - if (bdrv_pread(s->hd, sn->l1_table_offset, - s->l1_table, l1_size2) != l1_size2) - goto fail; - if (bdrv_pwrite(s->hd, s->l1_table_offset, - s->l1_table, l1_size2) != l1_size2) - goto fail; - for(i = 0;i < s->l1_size; i++) { - be64_to_cpus(&s->l1_table[i]); - } - - if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) - goto fail; - -#ifdef DEBUG_ALLOC - check_refcounts(bs); -#endif - return 0; - fail: - return -EIO; -} - -static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) -{ - BDRVQcowState *s = bs->opaque; - QCowSnapshot *sn; - int snapshot_index, ret; - - snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); - if (snapshot_index < 0) - return -ENOENT; - sn = &s->snapshots[snapshot_index]; - - ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1); - if (ret < 0) - return ret; - /* must update the copied flag on the current cluster offsets */ - ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); - if (ret < 0) - return ret; - free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t)); - - qemu_free(sn->id_str); - qemu_free(sn->name); - memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); - s->nb_snapshots--; - ret = qcow_write_snapshots(bs); - if (ret < 0) { - /* XXX: restore snapshot if error ? */ - return ret; - } -#ifdef DEBUG_ALLOC - check_refcounts(bs); -#endif - return 0; -} - -static int qcow_snapshot_list(BlockDriverState *bs, - QEMUSnapshotInfo **psn_tab) -{ - BDRVQcowState *s = bs->opaque; - QEMUSnapshotInfo *sn_tab, *sn_info; - QCowSnapshot *sn; - int i; - - sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo)); - if (!sn_tab) - goto fail; - for(i = 0; i < s->nb_snapshots; i++) { - sn_info = sn_tab + i; - sn = s->snapshots + i; - pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), - sn->id_str); - pstrcpy(sn_info->name, sizeof(sn_info->name), - sn->name); - sn_info->vm_state_size = sn->vm_state_size; - sn_info->date_sec = sn->date_sec; - sn_info->date_nsec = sn->date_nsec; - sn_info->vm_clock_nsec = sn->vm_clock_nsec; - } - *psn_tab = sn_tab; - return s->nb_snapshots; - fail: - qemu_free(sn_tab); - *psn_tab = NULL; - return -ENOMEM; -} - -/*********************************************************/ -/* refcount handling */ - -static int refcount_init(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - int ret, refcount_table_size2, i; - - s->refcount_block_cache = qemu_malloc(s->cluster_size); - if (!s->refcount_block_cache) - goto fail; - refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); - s->refcount_table = qemu_malloc(refcount_table_size2); - if (!s->refcount_table) - goto fail; - if (s->refcount_table_size > 0) { - ret = bdrv_pread(s->hd, s->refcount_table_offset, - s->refcount_table, refcount_table_size2); - if (ret != refcount_table_size2) - goto fail; - for(i = 0; i < s->refcount_table_size; i++) - be64_to_cpus(&s->refcount_table[i]); - } - return 0; - fail: - return -ENOMEM; -} - -static void refcount_close(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - qemu_free(s->refcount_block_cache); - qemu_free(s->refcount_table); -} - - -static int load_refcount_block(BlockDriverState *bs, - int64_t refcount_block_offset) -{ - BDRVQcowState *s = bs->opaque; - int ret; - ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, - s->cluster_size); - if (ret != s->cluster_size) - return -EIO; - s->refcount_block_cache_offset = refcount_block_offset; - return 0; -} - -static int get_refcount(BlockDriverState *bs, int64_t cluster_index) -{ - BDRVQcowState *s = bs->opaque; - int refcount_table_index, block_index; - int64_t refcount_block_offset; - - refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); - if (refcount_table_index >= s->refcount_table_size) - return 0; - refcount_block_offset = s->refcount_table[refcount_table_index]; - if (!refcount_block_offset) - return 0; - if (refcount_block_offset != s->refcount_block_cache_offset) { - /* better than nothing: return allocated if read error */ - if (load_refcount_block(bs, refcount_block_offset) < 0) - return 1; - } - block_index = cluster_index & - ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); - return be16_to_cpu(s->refcount_block_cache[block_index]); -} - -/* return < 0 if error */ -static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) -{ - BDRVQcowState *s = bs->opaque; - int i, nb_clusters; - - nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits; - for(;;) { - if (get_refcount(bs, s->free_cluster_index) == 0) { - s->free_cluster_index++; - for(i = 1; i < nb_clusters; i++) { - if (get_refcount(bs, s->free_cluster_index) != 0) - goto not_found; - s->free_cluster_index++; - } -#ifdef DEBUG_ALLOC2 - printf("alloc_clusters: size=%lld -> %lld\n", - size, - (s->free_cluster_index - nb_clusters) << s->cluster_bits); -#endif - return (s->free_cluster_index - nb_clusters) << s->cluster_bits; - } else { - not_found: - s->free_cluster_index++; - } - } -} - -static int64_t alloc_clusters(BlockDriverState *bs, int64_t size) -{ - int64_t offset; - - offset = alloc_clusters_noref(bs, size); - update_refcount(bs, offset, size, 1); - return offset; -} - -/* only used to allocate compressed sectors. We try to allocate - contiguous sectors. size must be <= cluster_size */ -static int64_t alloc_bytes(BlockDriverState *bs, int size) -{ - BDRVQcowState *s = bs->opaque; - int64_t offset, cluster_offset; - int free_in_cluster; - - assert(size > 0 && size <= s->cluster_size); - if (s->free_byte_offset == 0) { - s->free_byte_offset = alloc_clusters(bs, s->cluster_size); - } - redo: - free_in_cluster = s->cluster_size - - (s->free_byte_offset & (s->cluster_size - 1)); - if (size <= free_in_cluster) { - /* enough space in current cluster */ - offset = s->free_byte_offset; - s->free_byte_offset += size; - free_in_cluster -= size; - if (free_in_cluster == 0) - s->free_byte_offset = 0; - if ((offset & (s->cluster_size - 1)) != 0) - update_cluster_refcount(bs, offset >> s->cluster_bits, 1); - } else { - offset = alloc_clusters(bs, s->cluster_size); - cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); - if ((cluster_offset + s->cluster_size) == offset) { - /* we are lucky: contiguous data */ - offset = s->free_byte_offset; - update_cluster_refcount(bs, offset >> s->cluster_bits, 1); - s->free_byte_offset += size; - } else { - s->free_byte_offset = offset; - goto redo; - } - } - return offset; -} - -static void free_clusters(BlockDriverState *bs, - int64_t offset, int64_t size) -{ - update_refcount(bs, offset, size, -1); -} - -static int grow_refcount_table(BlockDriverState *bs, int min_size) -{ - BDRVQcowState *s = bs->opaque; - int new_table_size, new_table_size2, refcount_table_clusters, i, ret; - uint64_t *new_table; - int64_t table_offset; - uint64_t data64; - uint32_t data32; - int old_table_size; - int64_t old_table_offset; - - if (min_size <= s->refcount_table_size) - return 0; - /* compute new table size */ - refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); - for(;;) { - if (refcount_table_clusters == 0) { - refcount_table_clusters = 1; - } else { - refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; - } - new_table_size = refcount_table_clusters << (s->cluster_bits - 3); - if (min_size <= new_table_size) - break; - } -#ifdef DEBUG_ALLOC2 - printf("grow_refcount_table from %d to %d\n", - s->refcount_table_size, - new_table_size); -#endif - new_table_size2 = new_table_size * sizeof(uint64_t); - new_table = qemu_mallocz(new_table_size2); - if (!new_table) - return -ENOMEM; - memcpy(new_table, s->refcount_table, - s->refcount_table_size * sizeof(uint64_t)); - for(i = 0; i < s->refcount_table_size; i++) - cpu_to_be64s(&new_table[i]); - /* Note: we cannot update the refcount now to avoid recursion */ - table_offset = alloc_clusters_noref(bs, new_table_size2); - ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); - if (ret != new_table_size2) - goto fail; - for(i = 0; i < s->refcount_table_size; i++) - be64_to_cpus(&new_table[i]); - - data64 = cpu_to_be64(table_offset); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset), - &data64, sizeof(data64)) != sizeof(data64)) - goto fail; - data32 = cpu_to_be32(refcount_table_clusters); - if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_clusters), - &data32, sizeof(data32)) != sizeof(data32)) - goto fail; - qemu_free(s->refcount_table); - old_table_offset = s->refcount_table_offset; - old_table_size = s->refcount_table_size; - s->refcount_table = new_table; - s->refcount_table_size = new_table_size; - s->refcount_table_offset = table_offset; - - update_refcount(bs, table_offset, new_table_size2, 1); - free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); - return 0; - fail: - free_clusters(bs, table_offset, new_table_size2); - qemu_free(new_table); - return -EIO; -} - -/* addend must be 1 or -1 */ -/* XXX: cache several refcount block clusters ? */ -static int update_cluster_refcount(BlockDriverState *bs, - int64_t cluster_index, - int addend) -{ - BDRVQcowState *s = bs->opaque; - int64_t offset, refcount_block_offset; - int ret, refcount_table_index, block_index, refcount; - uint64_t data64; - - refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); - if (refcount_table_index >= s->refcount_table_size) { - if (addend < 0) - return -EINVAL; - ret = grow_refcount_table(bs, refcount_table_index + 1); - if (ret < 0) - return ret; - } - refcount_block_offset = s->refcount_table[refcount_table_index]; - if (!refcount_block_offset) { - if (addend < 0) - return -EINVAL; - /* create a new refcount block */ - /* Note: we cannot update the refcount now to avoid recursion */ - offset = alloc_clusters_noref(bs, s->cluster_size); - memset(s->refcount_block_cache, 0, s->cluster_size); - ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); - if (ret != s->cluster_size) - return -EINVAL; - s->refcount_table[refcount_table_index] = offset; - data64 = cpu_to_be64(offset); - ret = bdrv_pwrite(s->hd, s->refcount_table_offset + - refcount_table_index * sizeof(uint64_t), - &data64, sizeof(data64)); - if (ret != sizeof(data64)) - return -EINVAL; - - refcount_block_offset = offset; - s->refcount_block_cache_offset = offset; - update_refcount(bs, offset, s->cluster_size, 1); - } else { - if (refcount_block_offset != s->refcount_block_cache_offset) { - if (load_refcount_block(bs, refcount_block_offset) < 0) - return -EIO; - } - } - /* we can update the count and save it */ - block_index = cluster_index & - ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); - refcount = be16_to_cpu(s->refcount_block_cache[block_index]); - refcount += addend; - if (refcount < 0 || refcount > 0xffff) - return -EINVAL; - if (refcount == 0 && cluster_index < s->free_cluster_index) { - s->free_cluster_index = cluster_index; - } - s->refcount_block_cache[block_index] = cpu_to_be16(refcount); - if (bdrv_pwrite(s->hd, - refcount_block_offset + (block_index << REFCOUNT_SHIFT), - &s->refcount_block_cache[block_index], 2) != 2) - return -EIO; - return refcount; -} - -static void update_refcount(BlockDriverState *bs, - int64_t offset, int64_t length, - int addend) -{ - BDRVQcowState *s = bs->opaque; - int64_t start, last, cluster_offset; - -#ifdef DEBUG_ALLOC2 - printf("update_refcount: offset=%lld size=%lld addend=%d\n", - offset, length, addend); -#endif - if (length <= 0) - return; - start = offset & ~(s->cluster_size - 1); - last = (offset + length - 1) & ~(s->cluster_size - 1); - for(cluster_offset = start; cluster_offset <= last; - cluster_offset += s->cluster_size) { - update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend); - } -} - -#ifdef DEBUG_ALLOC -static void inc_refcounts(BlockDriverState *bs, - uint16_t *refcount_table, - int refcount_table_size, - int64_t offset, int64_t size) -{ - BDRVQcowState *s = bs->opaque; - int64_t start, last, cluster_offset; - int k; - - if (size <= 0) - return; - - start = offset & ~(s->cluster_size - 1); - last = (offset + size - 1) & ~(s->cluster_size - 1); - for(cluster_offset = start; cluster_offset <= last; - cluster_offset += s->cluster_size) { - k = cluster_offset >> s->cluster_bits; - if (k < 0 || k >= refcount_table_size) { - printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset); - } else { - if (++refcount_table[k] == 0) { - printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset); - } - } - } -} - -static int check_refcounts_l1(BlockDriverState *bs, - uint16_t *refcount_table, - int refcount_table_size, - int64_t l1_table_offset, int l1_size, - int check_copied) -{ - BDRVQcowState *s = bs->opaque; - uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2; - int l2_size, i, j, nb_csectors, refcount; - - l2_table = NULL; - l1_size2 = l1_size * sizeof(uint64_t); - - inc_refcounts(bs, refcount_table, refcount_table_size, - l1_table_offset, l1_size2); - - l1_table = qemu_malloc(l1_size2); - if (!l1_table) - goto fail; - if (bdrv_pread(s->hd, l1_table_offset, - l1_table, l1_size2) != l1_size2) - goto fail; - for(i = 0;i < l1_size; i++) - be64_to_cpus(&l1_table[i]); - - l2_size = s->l2_size * sizeof(uint64_t); - l2_table = qemu_malloc(l2_size); - if (!l2_table) - goto fail; - for(i = 0; i < l1_size; i++) { - l2_offset = l1_table[i]; - if (l2_offset) { - if (check_copied) { - refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); - if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { - printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n", - l2_offset, refcount); - } - } - l2_offset &= ~QCOW_OFLAG_COPIED; - if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) - goto fail; - for(j = 0; j < s->l2_size; j++) { - offset = be64_to_cpu(l2_table[j]); - if (offset != 0) { - if (offset & QCOW_OFLAG_COMPRESSED) { - if (offset & QCOW_OFLAG_COPIED) { - printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n", - offset >> s->cluster_bits); - offset &= ~QCOW_OFLAG_COPIED; - } - nb_csectors = ((offset >> s->csize_shift) & - s->csize_mask) + 1; - offset &= s->cluster_offset_mask; - inc_refcounts(bs, refcount_table, - refcount_table_size, - offset & ~511, nb_csectors * 512); - } else { - if (check_copied) { - refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); - if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) { - printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n", - offset, refcount); - } - } - offset &= ~QCOW_OFLAG_COPIED; - inc_refcounts(bs, refcount_table, - refcount_table_size, - offset, s->cluster_size); - } - } - } - inc_refcounts(bs, refcount_table, - refcount_table_size, - l2_offset, - s->cluster_size); - } - } - qemu_free(l1_table); - qemu_free(l2_table); - return 0; - fail: - printf("ERROR: I/O error in check_refcounts_l1\n"); - qemu_free(l1_table); - qemu_free(l2_table); - return -EIO; -} - -static void check_refcounts(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - int64_t size; - int nb_clusters, refcount1, refcount2, i; - QCowSnapshot *sn; - uint16_t *refcount_table; - - size = bdrv_getlength(s->hd); - nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits; - refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t)); - - /* header */ - inc_refcounts(bs, refcount_table, nb_clusters, - 0, s->cluster_size); - - check_refcounts_l1(bs, refcount_table, nb_clusters, - s->l1_table_offset, s->l1_size, 1); - - /* snapshots */ - for(i = 0; i < s->nb_snapshots; i++) { - sn = s->snapshots + i; - check_refcounts_l1(bs, refcount_table, nb_clusters, - sn->l1_table_offset, sn->l1_size, 0); - } - inc_refcounts(bs, refcount_table, nb_clusters, - s->snapshots_offset, s->snapshots_size); - - /* refcount data */ - inc_refcounts(bs, refcount_table, nb_clusters, - s->refcount_table_offset, - s->refcount_table_size * sizeof(uint64_t)); - for(i = 0; i < s->refcount_table_size; i++) { - int64_t offset; - offset = s->refcount_table[i]; - if (offset != 0) { - inc_refcounts(bs, refcount_table, nb_clusters, - offset, s->cluster_size); - } - } - - /* compare ref counts */ - for(i = 0; i < nb_clusters; i++) { - refcount1 = get_refcount(bs, i); - refcount2 = refcount_table[i]; - if (refcount1 != refcount2) - printf("ERROR cluster %d refcount=%d reference=%d\n", - i, refcount1, refcount2); - } - - qemu_free(refcount_table); -} - -#if 0 -static void dump_refcounts(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - int64_t nb_clusters, k, k1, size; - int refcount; - - size = bdrv_getlength(s->hd); - nb_clusters = (size + s->cluster_size - 1) >> s->cluster_bits; - for(k = 0; k < nb_clusters;) { - k1 = k; - refcount = get_refcount(bs, k); - k++; - while (k < nb_clusters && get_refcount(bs, k) == refcount) - k++; - printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1); - } -} -#endif -#endif - -BlockDriver bdrv_qcow2 = { - "qcow2", - sizeof(BDRVQcowState), - qcow_probe, - qcow_open, - NULL, - NULL, - qcow_close, - qcow_create, - qcow_flush, - qcow_is_allocated, - qcow_set_key, - qcow_make_empty, - - .bdrv_aio_read = qcow_aio_read, - .bdrv_aio_write = qcow_aio_write, - .bdrv_aio_cancel = qcow_aio_cancel, - .aiocb_size = sizeof(QCowAIOCB), - .bdrv_write_compressed = qcow_write_compressed, - - .bdrv_snapshot_create = qcow_snapshot_create, - .bdrv_snapshot_goto = qcow_snapshot_goto, - .bdrv_snapshot_delete = qcow_snapshot_delete, - .bdrv_snapshot_list = qcow_snapshot_list, - .bdrv_get_info = qcow_get_info, -}; |