The quilt patch titled Subject: readahead: fix return value of page_cache_next_miss() when no hole is found has been removed from the -mm tree. Its filename was readahead-fix-return-value-of-page_cache_next_miss-when-no-hole-is-found.patch

This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: Chi Zhiling chizhiling@kylinos.cn Subject: readahead: fix return value of page_cache_next_miss() when no hole is found Date: Thu, 5 Jun 2025 13:49:35 +0800

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 ---

mm/filemap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/mm/filemap.c~readahead-fix-return-value-of-page_cache_next_miss-when-no-hole-is-found +++ a/mm/filemap.c @@ -1778,8 +1778,9 @@ pgoff_t page_cache_next_miss(struct addr pgoff_t index, unsigned long max_scan) { XA_STATE(xas, &mapping->i_pages, index); + unsigned long nr = max_scan;

- while (max_scan--) { + while (nr--) { void *entry = xas_next(&xas); if (!entry || xa_is_value(entry)) return xas.xa_index; _

Patches currently in -mm which might be from chizhiling@kylinos.cn are