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authorChristoph Hellwig <hch@lst.de>2010-05-04 12:44:52 +0200
committerKevin Wolf <kwolf@redhat.com>2010-05-17 10:20:04 +0200
commit20be49e47e82f1b9fdc33810e1c4d7121871eafa (patch)
tree70832a03e99840d1c3bfb9569319eda162506259 /block/cloop.c
parentc94304be3f07fc038f0d8d48ffdca11a28b5aaca (diff)
cloop: use qemu block API
Use bdrv_pwrite to access the backing device instead of pread, and convert the driver to implementing the bdrv_open method which gives it an already opened BlockDriverState for the underlying device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/cloop.c')
-rw-r--r--block/cloop.c26
1 files changed, 12 insertions, 14 deletions
diff --git a/block/cloop.c b/block/cloop.c
index 9fe2a42363..fe015c4255 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -27,7 +27,6 @@
#include <zlib.h>
typedef struct BDRVCloopState {
- int fd;
uint32_t block_size;
uint32_t n_blocks;
uint64_t* offsets;
@@ -51,23 +50,20 @@ static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
return 0;
}
-static int cloop_open(BlockDriverState *bs, const char *filename, int flags)
+static int cloop_open(BlockDriverState *bs, int flags)
{
BDRVCloopState *s = bs->opaque;
uint32_t offsets_size,max_compressed_block_size=1,i;
- s->fd = open(filename, O_RDONLY | O_BINARY);
- if (s->fd < 0)
- return -errno;
bs->read_only = 1;
/* read header */
- if (pread(s->fd, &s->block_size, 4, 128) < 4) {
+ if (bdrv_pread(bs->file, 128, &s->block_size, 4) < 4) {
goto cloop_close;
}
s->block_size = be32_to_cpu(s->block_size);
- if (pread(s->fd, &s->n_blocks, 4, 128 + 4) < 4) {
+ if (bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4) < 4) {
goto cloop_close;
}
s->n_blocks = be32_to_cpu(s->n_blocks);
@@ -75,7 +71,8 @@ static int cloop_open(BlockDriverState *bs, const char *filename, int flags)
/* read offsets */
offsets_size = s->n_blocks * sizeof(uint64_t);
s->offsets = qemu_malloc(offsets_size);
- if (pread(s->fd, s->offsets, offsets_size, 128 + 4 + 4) < offsets_size) {
+ if (bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size) <
+ offsets_size) {
goto cloop_close;
}
for(i=0;i<s->n_blocks;i++) {
@@ -99,17 +96,19 @@ static int cloop_open(BlockDriverState *bs, const char *filename, int flags)
return 0;
cloop_close:
- close(s->fd);
return -1;
}
-static inline int cloop_read_block(BDRVCloopState *s,int block_num)
+static inline int cloop_read_block(BlockDriverState *bs, int block_num)
{
+ BDRVCloopState *s = bs->opaque;
+
if(s->current_block != block_num) {
int ret;
uint32_t bytes = s->offsets[block_num+1]-s->offsets[block_num];
- ret = pread(s->fd, s->compressed_block, bytes, s->offsets[block_num]);
+ ret = bdrv_pread(bs->file, s->offsets[block_num], s->compressed_block,
+ bytes);
if (ret != bytes)
return -1;
@@ -138,7 +137,7 @@ static int cloop_read(BlockDriverState *bs, int64_t sector_num,
for(i=0;i<nb_sectors;i++) {
uint32_t sector_offset_in_block=((sector_num+i)%s->sectors_per_block),
block_num=(sector_num+i)/s->sectors_per_block;
- if(cloop_read_block(s, block_num) != 0)
+ if(cloop_read_block(bs, block_num) != 0)
return -1;
memcpy(buf+i*512,s->uncompressed_block+sector_offset_in_block*512,512);
}
@@ -148,7 +147,6 @@ static int cloop_read(BlockDriverState *bs, int64_t sector_num,
static void cloop_close(BlockDriverState *bs)
{
BDRVCloopState *s = bs->opaque;
- close(s->fd);
if(s->n_blocks>0)
free(s->offsets);
free(s->compressed_block);
@@ -160,7 +158,7 @@ static BlockDriver bdrv_cloop = {
.format_name = "cloop",
.instance_size = sizeof(BDRVCloopState),
.bdrv_probe = cloop_probe,
- .bdrv_file_open = cloop_open,
+ .bdrv_open = cloop_open,
.bdrv_read = cloop_read,
.bdrv_close = cloop_close,
};