mirror of https://gitee.com/openkylin/qemu.git
205 lines
5.9 KiB
C
205 lines
5.9 KiB
C
/*
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* QEMU Block driver for CLOOP images
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*
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* Copyright (c) 2004 Johannes E. Schindelin
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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 "qemu-common.h"
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#include "block/block_int.h"
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#include "qemu/module.h"
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#include <zlib.h>
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typedef struct BDRVCloopState {
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CoMutex lock;
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uint32_t block_size;
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uint32_t n_blocks;
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uint64_t *offsets;
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uint32_t sectors_per_block;
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uint32_t current_block;
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uint8_t *compressed_block;
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uint8_t *uncompressed_block;
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z_stream zstream;
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} BDRVCloopState;
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static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
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{
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const char *magic_version_2_0 = "#!/bin/sh\n"
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"#V2.0 Format\n"
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"modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
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int length = strlen(magic_version_2_0);
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if (length > buf_size) {
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length = buf_size;
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}
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if (!memcmp(magic_version_2_0, buf, length)) {
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return 2;
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}
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return 0;
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}
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static int cloop_open(BlockDriverState *bs, int flags)
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{
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BDRVCloopState *s = bs->opaque;
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uint32_t offsets_size, max_compressed_block_size = 1, i;
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int ret;
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bs->read_only = 1;
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/* read header */
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ret = bdrv_pread(bs->file, 128, &s->block_size, 4);
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if (ret < 0) {
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return ret;
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}
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s->block_size = be32_to_cpu(s->block_size);
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ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
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if (ret < 0) {
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return ret;
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}
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s->n_blocks = be32_to_cpu(s->n_blocks);
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/* read offsets */
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offsets_size = s->n_blocks * sizeof(uint64_t);
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s->offsets = g_malloc(offsets_size);
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ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size);
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if (ret < 0) {
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goto fail;
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}
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for(i=0;i<s->n_blocks;i++) {
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s->offsets[i] = be64_to_cpu(s->offsets[i]);
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if (i > 0) {
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uint32_t size = s->offsets[i] - s->offsets[i - 1];
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if (size > max_compressed_block_size) {
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max_compressed_block_size = size;
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}
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}
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}
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/* initialize zlib engine */
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s->compressed_block = g_malloc(max_compressed_block_size + 1);
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s->uncompressed_block = g_malloc(s->block_size);
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if (inflateInit(&s->zstream) != Z_OK) {
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ret = -EINVAL;
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goto fail;
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}
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s->current_block = s->n_blocks;
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s->sectors_per_block = s->block_size/512;
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bs->total_sectors = s->n_blocks * s->sectors_per_block;
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qemu_co_mutex_init(&s->lock);
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return 0;
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fail:
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g_free(s->offsets);
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g_free(s->compressed_block);
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g_free(s->uncompressed_block);
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return ret;
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}
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static inline int cloop_read_block(BlockDriverState *bs, int block_num)
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{
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BDRVCloopState *s = bs->opaque;
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if (s->current_block != block_num) {
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int ret;
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uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
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ret = bdrv_pread(bs->file, s->offsets[block_num], s->compressed_block,
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bytes);
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if (ret != bytes) {
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return -1;
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}
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s->zstream.next_in = s->compressed_block;
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s->zstream.avail_in = bytes;
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s->zstream.next_out = s->uncompressed_block;
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s->zstream.avail_out = s->block_size;
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ret = inflateReset(&s->zstream);
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if (ret != Z_OK) {
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return -1;
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}
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ret = inflate(&s->zstream, Z_FINISH);
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if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
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return -1;
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}
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s->current_block = block_num;
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}
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return 0;
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}
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static int cloop_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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BDRVCloopState *s = bs->opaque;
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int i;
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for (i = 0; i < nb_sectors; i++) {
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uint32_t sector_offset_in_block =
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((sector_num + i) % s->sectors_per_block),
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block_num = (sector_num + i) / s->sectors_per_block;
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if (cloop_read_block(bs, block_num) != 0) {
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return -1;
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}
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memcpy(buf + i * 512,
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s->uncompressed_block + sector_offset_in_block * 512, 512);
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}
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return 0;
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}
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static coroutine_fn int cloop_co_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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int ret;
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BDRVCloopState *s = bs->opaque;
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qemu_co_mutex_lock(&s->lock);
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ret = cloop_read(bs, sector_num, buf, nb_sectors);
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qemu_co_mutex_unlock(&s->lock);
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return ret;
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}
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static void cloop_close(BlockDriverState *bs)
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{
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BDRVCloopState *s = bs->opaque;
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if (s->n_blocks > 0) {
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g_free(s->offsets);
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}
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g_free(s->compressed_block);
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g_free(s->uncompressed_block);
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inflateEnd(&s->zstream);
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}
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static BlockDriver bdrv_cloop = {
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.format_name = "cloop",
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.instance_size = sizeof(BDRVCloopState),
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.bdrv_probe = cloop_probe,
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.bdrv_open = cloop_open,
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.bdrv_read = cloop_co_read,
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.bdrv_close = cloop_close,
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};
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static void bdrv_cloop_init(void)
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{
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bdrv_register(&bdrv_cloop);
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}
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block_init(bdrv_cloop_init);
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