@@ -900,15 +900,15 @@ out:
* Check if there already is an AIO write request in flight which allocates
* the same cluster. In this case we need to wait until the previous
* request has completed and updated the L2 table accordingly.
- *
* Returns:
* 0 if there was no dependency. *cur_bytes indicates the number of
* bytes from guest_offset that can be read before the next
- * dependency must be processed (or the request is complete)
+ * dependency must be processed (or the request is complete).
+ * *m is not modified
*
- * -EAGAIN if we had to wait for another request, previously gathered
- * information on cluster allocation may be invalid now. The caller
- * must start over anyway, so consider *cur_bytes undefined.
+ * -EAGAIN if we had to wait for another request. The caller
+ * must start over, so consider *cur_bytes undefined.
+ * *m is not modified
*/
static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
uint64_t *cur_bytes, QCowL2Meta **m)
@@ -919,10 +919,10 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) {
- uint64_t start = guest_offset;
- uint64_t end = start + bytes;
- uint64_t old_start = l2meta_cow_start(old_alloc);
- uint64_t old_end = l2meta_cow_end(old_alloc);
+ const uint64_t start = guest_offset;
+ const uint64_t end = start + bytes;
+ const uint64_t old_start = l2meta_cow_start(old_alloc);
+ const uint64_t old_end = l2meta_cow_end(old_alloc);
if (end <= old_start || start >= old_end) {
/* No intersection */
@@ -939,6 +939,8 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
* and deal with requests depending on them before starting to
* gather new ones. Not worth the trouble. */
if (bytes == 0 && *m) {
+ /* start must be cluster aligned at this point */
+ assert(start == start_of_cluster(s, start));
*cur_bytes = 0;
return 0;
}
- assert the alignment on return if the allocation has to stop (at the start of a running allocation) - make use of const specifiers for local variables Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> --- block/qcow2-cluster.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)