On Tue, Nov 3, 2020 at 5:21 PM Wonhuyk Yang <vvghjk1234@xxxxxxxxx> wrote: > > From: Wonhyuk Yang <vvghjk1234@xxxxxxxxx> > > Thank you for your reply. > > > By the way, this isn't right. You meant 'if (xa_is_value(page))'. > > I think you missed a ! operator. Actually I was not sure that there > are other internal entries except retry entry and zero entry in > the xas_for_each(). > > > The reason we can see a retry entry here is that we did a readahead of a > > single page at index 0. Between that page being inserted and the lookup, > > another page was removed from the file (maybe the file was truncated > > down) and this caused the node to be removed, and the pointer to the > > page got moved into the root of the tree. The pointer in the node was > > replaced with a retry entry, indicating that the page is still valid, > > it just isn't here any more. And so we retry the lookup. > > It's a little difficult for me, but thank you for your specific explanation. Could you link the earlier thread for reference? You forgot to include it in your email subtext. Best regards, Amy Parker (they/them)
