max_scan in page_cache_next_miss always decreases to zero when no hole is found, causing the return value to be index + 0. Fix this by preserving the max_scan value throughout the loop. Jan said "From what I know and have seen in the past, wrong responses from page_cache_next_miss() can lead to readahead window reduction and thus reduced read speeds." Link: https://lkml.kernel.org/r/20250605054935.2323451-1-chizhiling@163.com Fixes: 901a269ff3d5 ("filemap: fix page_cache_next_miss() when no hole found") Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>