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bochs: Implement .bdrv_co_preadv() interface

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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 14:53:22 +02:00
parent 3fb06697ae
commit 3b8fd33011
1 changed files with 33 additions and 18 deletions
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51
block/bochs.c
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@ -104,6 +104,7 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
int ret;
bs->read_only = 1; // no write support yet
bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */
ret = bdrv_pread(bs->file->bs, 0, &bochs, sizeof(bochs));
if (ret < 0) {
@ -221,38 +222,52 @@ static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
return bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
}
static int bochs_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
static int coroutine_fn
bochs_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
BDRVBochsState *s = bs->opaque;
uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
int nb_sectors = bytes >> BDRV_SECTOR_BITS;
uint64_t bytes_done = 0;
QEMUIOVector local_qiov;
int ret;
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
qemu_iovec_init(&local_qiov, qiov->niov);
qemu_co_mutex_lock(&s->lock);
while (nb_sectors > 0) {
int64_t block_offset = seek_to_sector(bs, sector_num);
if (block_offset < 0) {
return block_offset;
} else if (block_offset > 0) {
ret = bdrv_pread(bs->file->bs, block_offset, buf, 512);
ret = block_offset;
goto fail;
}
qemu_iovec_reset(&local_qiov);
qemu_iovec_concat(&local_qiov, qiov, bytes_done, 512);
if (block_offset > 0) {
ret = bdrv_co_preadv(bs->file->bs, block_offset, 512,
&local_qiov, 0);
if (ret < 0) {
return ret;
goto fail;
}
} else {
memset(buf, 0, 512);
qemu_iovec_memset(&local_qiov, 0, 0, 512);
}
nb_sectors--;
sector_num++;
buf += 512;
bytes_done += 512;
}
return 0;
}
static coroutine_fn int bochs_co_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int ret;
BDRVBochsState *s = bs->opaque;
qemu_co_mutex_lock(&s->lock);
ret = bochs_read(bs, sector_num, buf, nb_sectors);
ret = 0;
fail:
qemu_co_mutex_unlock(&s->lock);
qemu_iovec_destroy(&local_qiov);
return ret;
}
@ -267,7 +282,7 @@ static BlockDriver bdrv_bochs = {
.instance_size = sizeof(BDRVBochsState),
.bdrv_probe = bochs_probe,
.bdrv_open = bochs_open,
.bdrv_read = bochs_co_read,
.bdrv_co_preadv = bochs_co_preadv,
.bdrv_close = bochs_close,
};