On Mon, Apr 17, 2023 at 4:24 AM Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> wrote: > > On (23/04/17 04:16), Yosry Ahmed wrote: > > > That's a good question to which I don't have an answer. We can list_add() > > > the same zspage twice, unlocking the pool after first list_add() so that > > > another process (including another zs_compact()) can do something to that > > > zspage. The answer is somewhere between these lines, I guess. > > > > But the first list_add() is (in this case) the correct add, so we > > expect other processes to be able to access the zspage after the first > > list_add() anyway, right? > > Correct. Compaction also can unlock pool->lock and schedule() so that > another process can access the source zspage, when compaction gets > scheduled it can attempt putback/unlock the same zspage one more time > (the zspage may not even exist at this point, I assume). Good point, that could very well be where the corruption is coming from. Thanks for pointing this out.
