block-vpc: Use the qemu block layer (Kevin Wolf)
Instead of accessing the file directly, use the qemu block layer. Signed-off-by: Kevin Wolf <kwolf@suse.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6457 c046a42c-6fe2-441c-8c8c-71466251a162
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parent
1fa792286c
commit
b71d1c2e11
59
block-vpc.c
59
block-vpc.c
@ -105,7 +105,7 @@ struct vhd_dyndisk_header {
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};
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typedef struct BDRVVPCState {
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int fd;
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BlockDriverState *hd;
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int max_table_entries;
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uint32_t *pagetable;
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@ -130,20 +130,18 @@ static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
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static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
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{
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BDRVVPCState *s = bs->opaque;
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int fd, i;
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int ret, i;
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struct vhd_footer* footer;
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struct vhd_dyndisk_header* dyndisk_header;
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uint8_t buf[HEADER_SIZE];
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fd = open(filename, O_RDONLY | O_BINARY);
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if (fd < 0)
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return -1;
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bs->read_only = 1; // no write support yet
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s->fd = fd;
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ret = bdrv_file_open(&s->hd, filename, flags);
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if (ret < 0)
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return ret;
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if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
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if (bdrv_pread(s->hd, 0, buf, HEADER_SIZE) != HEADER_SIZE)
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goto fail;
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footer = (struct vhd_footer*) buf;
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@ -156,8 +154,8 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
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bs->total_sectors = (int64_t)
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be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
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lseek(s->fd, be64_to_cpu(footer->data_offset), SEEK_SET);
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if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
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if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
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!= HEADER_SIZE)
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goto fail;
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footer = NULL;
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@ -166,15 +164,16 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
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if (strncmp(dyndisk_header->magic, "cxsparse", 8))
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goto fail;
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lseek(s->fd, be64_to_cpu(dyndisk_header->table_offset), SEEK_SET);
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s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
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s->pagetable = qemu_malloc(s->max_table_entries * 4);
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if (!s->pagetable)
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goto fail;
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if (read(s->fd, s->pagetable, s->max_table_entries * 4) !=
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s->max_table_entries * 4)
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goto fail;
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goto fail;
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if (bdrv_pread(s->hd, be64_to_cpu(dyndisk_header->table_offset),
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s->pagetable, s->max_table_entries * 4) != s->max_table_entries * 4)
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goto fail;
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for (i = 0; i < s->max_table_entries; i++)
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be32_to_cpus(&s->pagetable[i]);
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@ -190,11 +189,15 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
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return 0;
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fail:
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close(fd);
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bdrv_delete(s->hd);
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return -1;
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}
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static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
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/*
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* Returns the absolute byte offset of the given sector in the image file.
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* If the sector is not allocated, -1 is returned instead.
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*/
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static inline int64_t get_sector_offset(BlockDriverState *bs, int64_t sector_num)
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{
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BDRVVPCState *s = bs->opaque;
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uint64_t offset = sector_num * 512;
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@ -241,9 +244,8 @@ static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
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return -1; // not allocated
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#endif
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#endif
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lseek(s->fd, block_offset, SEEK_SET);
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return 0;
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return block_offset;
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}
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static int vpc_read(BlockDriverState *bs, int64_t sector_num,
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@ -251,16 +253,19 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
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{
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BDRVVPCState *s = bs->opaque;
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int ret;
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int64_t offset;
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while (nb_sectors > 0) {
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if (!seek_to_sector(bs, sector_num))
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{
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ret = read(s->fd, buf, 512);
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if (ret != 512)
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return -1;
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}
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else
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offset = get_sector_offset(bs, sector_num);
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if (offset == -1) {
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memset(buf, 0, 512);
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} else {
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ret = bdrv_pread(s->hd, offset, buf, 512);
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if (ret != 512)
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return -1;
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}
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nb_sectors--;
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sector_num++;
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buf += 512;
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@ -275,7 +280,7 @@ static void vpc_close(BlockDriverState *bs)
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#ifdef CACHE
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qemu_free(s->pageentry_u8);
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#endif
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close(s->fd);
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bdrv_delete(s->hd);
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}
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BlockDriver bdrv_vpc = {
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