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qcow2: Make perform_cow() call do_perform_cow() twice

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Instead of calling perform_cow() twice with a different COW region
each time, call it just once and make perform_cow() handle both
regions.

This patch simply moves code around. The next one will do the actual
reordering of the COW operations.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Alberto Garcia 2017-06-19 16:40:04 +03:00 committed by Kevin Wolf
parent e034f5bcbc
commit 99450c6fb9
1 changed files with 22 additions and 14 deletions
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34
block/qcow2-cluster.c
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@ -414,6 +414,10 @@ static int coroutine_fn do_perform_cow(BlockDriverState *bs,
struct iovec iov;
int ret;
if (bytes == 0) {
return 0;
}
iov.iov_len = bytes;
iov.iov_base = qemu_try_blockalign(bs, iov.iov_len);
if (iov.iov_base == NULL) {
@ -751,31 +755,40 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
return cluster_offset;
}
static int perform_cow(BlockDriverState *bs, QCowL2Meta *m, Qcow2COWRegion *r)
static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
{
BDRVQcow2State *s = bs->opaque;
Qcow2COWRegion *start = &m->cow_start;
Qcow2COWRegion *end = &m->cow_end;
int ret;
if (r->nb_bytes == 0) {
if (start->nb_bytes == 0 && end->nb_bytes == 0) {
return 0;
}
qemu_co_mutex_unlock(&s->lock);
ret = do_perform_cow(bs, m->offset, m->alloc_offset, r->offset, r->nb_bytes);
qemu_co_mutex_lock(&s->lock);
ret = do_perform_cow(bs, m->offset, m->alloc_offset,
start->offset, start->nb_bytes);
if (ret < 0) {
return ret;
goto fail;
}
ret = do_perform_cow(bs, m->offset, m->alloc_offset,
end->offset, end->nb_bytes);
fail:
qemu_co_mutex_lock(&s->lock);
/*
* Before we update the L2 table to actually point to the new cluster, we
* need to be sure that the refcounts have been increased and COW was
* handled.
*/
if (ret == 0) {
qcow2_cache_depends_on_flush(s->l2_table_cache);
}
return 0;
return ret;
}
int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
@ -795,12 +808,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
}
/* copy content of unmodified sectors */
ret = perform_cow(bs, m, &m->cow_start);
if (ret < 0) {
goto err;
}
ret = perform_cow(bs, m, &m->cow_end);
ret = perform_cow(bs, m);
if (ret < 0) {
goto err;
}