cloop: Implement .bdrv_co_preadv() interface

This implements .bdrv_co_preadv() for the cloop block driver. While
updating the error paths, change -1 to a valid -errno code.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-04-25 15:21:46 +02:00
parent 3b8fd33011
commit 5cd230819e

View File

@ -66,6 +66,7 @@ static int cloop_open(BlockDriverState *bs, QDict *options, int flags,
int ret;
bs->read_only = 1;
bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */
/* read header */
ret = bdrv_pread(bs->file->bs, 128, &s->block_size, 4);
@ -229,33 +230,38 @@ static inline int cloop_read_block(BlockDriverState *bs, int block_num)
return 0;
}
static int cloop_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
static int coroutine_fn
cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
BDRVCloopState *s = bs->opaque;
int i;
uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
int ret, i;
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
qemu_co_mutex_lock(&s->lock);
for (i = 0; i < nb_sectors; i++) {
void *data;
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(bs, block_num) != 0) {
return -1;
ret = -EIO;
goto fail;
}
memcpy(buf + i * 512,
s->uncompressed_block + sector_offset_in_block * 512, 512);
}
return 0;
}
static coroutine_fn int cloop_co_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int ret;
BDRVCloopState *s = bs->opaque;
qemu_co_mutex_lock(&s->lock);
ret = cloop_read(bs, sector_num, buf, nb_sectors);
data = s->uncompressed_block + sector_offset_in_block * 512;
qemu_iovec_from_buf(qiov, i * 512, data, 512);
}
ret = 0;
fail:
qemu_co_mutex_unlock(&s->lock);
return ret;
}
@ -273,7 +279,7 @@ static BlockDriver bdrv_cloop = {
.instance_size = sizeof(BDRVCloopState),
.bdrv_probe = cloop_probe,
.bdrv_open = cloop_open,
.bdrv_read = cloop_co_read,
.bdrv_co_preadv = cloop_co_preadv,
.bdrv_close = cloop_close,
};