On 11/20/19 8:02 AM, Pavel Begunkov wrote: > On 11/20/2019 5:22 PM, Jens Axboe wrote: >>> However, this is only true if linked timeout isn't fired. Otherwise, >>> there is another bug, which isn't fixed by either of the patches. We >>> need to clear REQ_F_LINK_TIMEOUT in io_link_timeout_fn() as well. >>> >>> Let: REQ -> L_TIMEOUT1 -> L_TIMEOUT2 >>> 1. L_TIMEOUT1 fired before REQ is completed >>> >>> 2. io_link_timeout_fn() removes L_TIMEOUT1 from the list: >>> REQ|REQ_F_LINK_TIMEOUT -> L_TIMEOUT2 >>> >>> 3. free_req(REQ) then call io_link_cancel_timeout(L_TIMEOUT2) >>> leaking it (as described in my patch). >>> >>> P.S. haven't tried to test nor reproduce it yet. >> >> That's exactly the case I was worried about. In any case, it seems >> prudent to handle it defensively. >> > Yeah, I've got from the patch that may have missed something. > > Will you add this "should clear REQ_F_LINK_TIMEOUT in > io_link_timeout_fn()" (e.g. in v2), or should I? I'll add it in the v2. -- Jens Axboe
