I won't apply this version, please send v12 with the changes below. On 11/9/26 15:01, Alexander Ivanov wrote: > spin_unlock_irqrestore(&qcow2->md_pages_lock, flags); > > + list_for_each_entry(qio, &end_list, link) > + qio->ext->cleanup_mask &= ~FREE_ALLOCATED_CLU; > qcow2_dispatch_qios(qcow2, NULL, &wait_list);
Item 1 of the cover letter reply: queue the L1-allocation qio on l1.md->wbd->dependent_list instead of l1.md->wait_list. Why: that qio does not reach end_list. It waits on l1.md->wait_list, and on a failed L1 writeback clear_writeback_status() sends it back to work. The reverted L1 entry is 0 again, so it allocates another L2-table cluster, and the L1 page is written again in the same worker pass. Nothing slows this down: with a persistent L1 write error every round leaks one more cluster and grows the file. Before this patch the same loop freed the cluster and reused it. On success a dependent qio goes back to work the same way as a waiter, so moving it costs nothing there. Today only the qios added in process_indexes_write() sit on dependent_list, and they all have ext. A plain write that allocates an L2 table may have none, so check qio->ext in the new loop. > Keep the refcount of these clusters instead. If L1/L2 on disk points to > such a cluster, the image stays consistent; otherwise the cluster is > leaked, which check repairs by freeing it. So the image needs no check > and resume needs no refusal. Item 2 of the cover letter reply: say what is leaked, one cluster per failed L1/L2 write of a request. Why: your v10 answer bounded the leak by "refcounts reach the disk before L1/L2". In this driver it is the other way round: R1/R2 pages wait on slow_wb_batch_list for the timer (see the comment above mark_cluster_used()), while L1/L2 pages are written in the same worker pass. And an L1 update has no data write that could fail first. -- Konstantin Khorenko, Virtuozzo Linux Kernel Team _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
