On Mon, May 16, 2022 at 8:36 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Mon, May 16, 2022 at 07:04:08PM +0800, Hsin-Yi Wang wrote: > > > + loff_t req_end = readahead_pos(ractl) + readahead_length(ractl); > > > + loff_t start = readahead_pos(ractl) &~ mask; > > > + size_t len = readahead_length(ractl) + readahead_pos(ractl) - start; > > > + struct squashfs_page_actor *actor; > > > + unsigned int nr_pages = 0; > > > + struct page **pages; > > > + u64 block = 0; > > > + int bsize, res, i, index; > > > + int file_end = i_size_read(inode) >> msblk->block_log; > > > + unsigned int max_pages = 1UL << shift; > > > + > > > + readahead_expand(ractl, start, (len | mask) + 1); > > > + > > > + if (readahead_pos(ractl) + readahead_length(ractl) < req_end || > > > + file_end == 0) > > > + return; > > What's the first half of this condition supposed to be checking for? > It seems to be checking whether readahead_expand() shrunk the range > covered by the ractl, but readahead_expand() never does that, so I'm > confused why you're checking for it. hi Matthew, This is to check if readahead_expand() expands as much as it's requested. I didn't encounter the mismatch so far in my testing. If this check is not necessary, it can be removed.
