root / block-vmdk.c @ 977d5710
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/*
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* Block driver for the VMDK format
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*
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* Copyright (c) 2004 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "vl.h" |
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#include "block_int.h" |
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/* XXX: this code is untested */
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/* XXX: add write support */
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#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D') |
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#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V') |
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typedef struct { |
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uint32_t version; |
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uint32_t flags; |
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uint32_t disk_sectors; |
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uint32_t granularity; |
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uint32_t l1dir_offset; |
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uint32_t l1dir_size; |
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uint32_t file_sectors; |
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uint32_t cylinders; |
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uint32_t heads; |
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uint32_t sectors_per_track; |
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} VMDK3Header; |
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typedef struct { |
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uint32_t version; |
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uint32_t flags; |
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int64_t capacity; |
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int64_t granularity; |
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int64_t desc_offset; |
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int64_t desc_size; |
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int32_t num_gtes_per_gte; |
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int64_t rgd_offset; |
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int64_t gd_offset; |
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int64_t grain_offset; |
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char filler[1]; |
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char check_bytes[4]; |
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} VMDK4Header; |
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#define L2_CACHE_SIZE 16 |
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typedef struct BDRVVmdkState { |
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int fd;
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int64_t l1_table_offset; |
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uint32_t *l1_table; |
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unsigned int l1_size; |
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uint32_t l1_entry_sectors; |
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unsigned int l2_size; |
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uint32_t *l2_cache; |
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uint32_t l2_cache_offsets[L2_CACHE_SIZE]; |
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uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
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unsigned int cluster_sectors; |
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} BDRVVmdkState; |
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static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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uint32_t magic; |
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if (buf_size < 4) |
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return 0; |
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magic = be32_to_cpu(*(uint32_t *)buf); |
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if (magic == VMDK3_MAGIC ||
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magic == VMDK4_MAGIC) |
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return 100; |
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else
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return 0; |
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} |
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static int vmdk_open(BlockDriverState *bs, const char *filename) |
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{ |
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BDRVVmdkState *s = bs->opaque; |
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int fd, i;
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uint32_t magic; |
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int l1_size;
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fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); |
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if (fd < 0) |
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return -1; |
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if (read(fd, &magic, sizeof(magic)) != sizeof(magic)) |
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goto fail;
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magic = be32_to_cpu(magic); |
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if (magic == VMDK3_MAGIC) {
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VMDK3Header header; |
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if (read(fd, &header, sizeof(header)) != |
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sizeof(header))
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goto fail;
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s->cluster_sectors = le32_to_cpu(header.granularity); |
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s->l2_size = 1 << 9; |
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s->l1_size = 1 << 6; |
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bs->total_sectors = le32_to_cpu(header.disk_sectors); |
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s->l1_table_offset = le32_to_cpu(header.l1dir_offset) * 512;
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s->l1_entry_sectors = s->l2_size * s->cluster_sectors; |
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} else if (magic == VMDK4_MAGIC) { |
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VMDK4Header header; |
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if (read(fd, &header, sizeof(header)) != sizeof(header)) |
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goto fail;
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bs->total_sectors = le32_to_cpu(header.capacity); |
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s->cluster_sectors = le32_to_cpu(header.granularity); |
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s->l2_size = le32_to_cpu(header.num_gtes_per_gte); |
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s->l1_entry_sectors = s->l2_size * s->cluster_sectors; |
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if (s->l1_entry_sectors <= 0) |
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goto fail;
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s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
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/ s->l1_entry_sectors; |
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s->l1_table_offset = le64_to_cpu(header.rgd_offset) * 512;
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} else {
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goto fail;
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} |
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/* read the L1 table */
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l1_size = s->l1_size * sizeof(uint32_t);
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s->l1_table = qemu_malloc(l1_size); |
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if (!s->l1_table)
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goto fail;
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if (lseek(fd, s->l1_table_offset, SEEK_SET) == -1) |
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goto fail;
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if (read(fd, s->l1_table, l1_size) != l1_size)
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goto fail;
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for(i = 0; i < s->l1_size; i++) { |
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le32_to_cpus(&s->l1_table[i]); |
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} |
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
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if (!s->l2_cache)
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goto fail;
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s->fd = fd; |
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/* XXX: currently only read only */
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bs->read_only = 1;
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return 0; |
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fail:
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qemu_free(s->l1_table); |
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qemu_free(s->l2_cache); |
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close(fd); |
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return -1; |
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} |
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static uint64_t get_cluster_offset(BlockDriverState *bs,
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uint64_t offset) |
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{ |
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BDRVVmdkState *s = bs->opaque; |
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unsigned int l1_index, l2_offset, l2_index; |
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int min_index, i, j;
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uint32_t min_count, *l2_table; |
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uint64_t cluster_offset; |
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l1_index = (offset >> 9) / s->l1_entry_sectors;
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if (l1_index >= s->l1_size)
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return 0; |
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l2_offset = s->l1_table[l1_index]; |
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if (!l2_offset)
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return 0; |
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for(i = 0; i < L2_CACHE_SIZE; i++) { |
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if (l2_offset == s->l2_cache_offsets[i]) {
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/* increment the hit count */
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if (++s->l2_cache_counts[i] == 0xffffffff) { |
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for(j = 0; j < L2_CACHE_SIZE; j++) { |
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s->l2_cache_counts[j] >>= 1;
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} |
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} |
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l2_table = s->l2_cache + (i * s->l2_size); |
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goto found;
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} |
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} |
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/* not found: load a new entry in the least used one */
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min_index = 0;
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min_count = 0xffffffff;
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for(i = 0; i < L2_CACHE_SIZE; i++) { |
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if (s->l2_cache_counts[i] < min_count) {
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min_count = s->l2_cache_counts[i]; |
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min_index = i; |
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} |
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} |
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l2_table = s->l2_cache + (min_index * s->l2_size); |
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lseek(s->fd, (int64_t)l2_offset * 512, SEEK_SET);
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if (read(s->fd, l2_table, s->l2_size * sizeof(uint32_t)) != |
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s->l2_size * sizeof(uint32_t))
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return 0; |
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s->l2_cache_offsets[min_index] = l2_offset; |
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s->l2_cache_counts[min_index] = 1;
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found:
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l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
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cluster_offset = le32_to_cpu(l2_table[l2_index]); |
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cluster_offset <<= 9;
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return cluster_offset;
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} |
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static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num, |
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int nb_sectors, int *pnum) |
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{ |
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BDRVVmdkState *s = bs->opaque; |
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int index_in_cluster, n;
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uint64_t cluster_offset; |
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cluster_offset = get_cluster_offset(bs, sector_num << 9);
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index_in_cluster = sector_num % s->cluster_sectors; |
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n = s->cluster_sectors - index_in_cluster; |
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if (n > nb_sectors)
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n = nb_sectors; |
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*pnum = n; |
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return (cluster_offset != 0); |
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} |
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static int vmdk_read(BlockDriverState *bs, int64_t sector_num, |
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uint8_t *buf, int nb_sectors)
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{ |
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BDRVVmdkState *s = bs->opaque; |
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int ret, index_in_cluster, n;
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uint64_t cluster_offset; |
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while (nb_sectors > 0) { |
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cluster_offset = get_cluster_offset(bs, sector_num << 9);
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index_in_cluster = sector_num % s->cluster_sectors; |
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n = s->cluster_sectors - index_in_cluster; |
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if (n > nb_sectors)
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n = nb_sectors; |
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if (!cluster_offset) {
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memset(buf, 0, 512 * n); |
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} else {
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lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
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ret = read(s->fd, buf, n * 512);
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if (ret != n * 512) |
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return -1; |
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} |
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nb_sectors -= n; |
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sector_num += n; |
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buf += n * 512;
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} |
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return 0; |
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} |
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static int vmdk_write(BlockDriverState *bs, int64_t sector_num, |
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const uint8_t *buf, int nb_sectors) |
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{ |
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return -1; |
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} |
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static void vmdk_close(BlockDriverState *bs) |
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{ |
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BDRVVmdkState *s = bs->opaque; |
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qemu_free(s->l1_table); |
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qemu_free(s->l2_cache); |
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close(s->fd); |
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} |
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BlockDriver bdrv_vmdk = { |
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"vmdk",
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sizeof(BDRVVmdkState),
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vmdk_probe, |
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vmdk_open, |
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vmdk_read, |
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vmdk_write, |
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vmdk_close, |
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NULL, /* no create yet */ |
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vmdk_is_allocated, |
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}; |