Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > + while ((page = readahead_page(ractl))) > > + put_page(page); > > You don't need this pair of lines (unless I'm missing something). > read_pages() in mm/readahead.c puts the reference and unlocks any > pages which are not read by the readahead op. Indeed, I think doing > this is buggy because you don't unlock the page. Actually, I do need them. The pages haven't been removed from the ractl at this point so just returning would cause them all to be unlocked prematurely. I don't pass the ractl to the filesystem or the cache because I may be calling them for partial pages, I may be issuing multiple ops sequentially on a page and the ractl may have ceased to exist by the time I issue an op. The unlocking is done by netfs_rreq_unlock(), even for pages that didn't get read. I've added a comment to this effect. David
