From 4fa0e3ff217f775cb58d2d6d51820ec519243fb9 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Wed, 12 Oct 2022 20:34:19 +0100
Subject: [PATCH] ext4,f2fs: fix readahead of verity data
Git-commit: 4fa0e3ff217f775cb58d2d6d51820ec519243fb9
Patch-mainline: v6.1-rc1
References: bsc#1207648

The recent change of page_cache_ra_unbounded() arguments was buggy in the
two callers, causing us to readahead the wrong pages.  Move the definition
of ractl down to after the index is set correctly.  This affected
performance on configurations that use fs-verity.

Link: https://lkml.kernel.org/r/20221012193419.1453558-1-willy@infradead.org
Fixes: 73bb49da50cd ("mm/readahead: make page_cache_ra_unbounded take a readahead_control")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Jintao Yin <nicememory@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/ext4/verity.c | 3 ++-
 fs/f2fs/verity.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index b051d19b5c8a..94442c690ca7 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -365,13 +365,14 @@ static struct page *ext4_read_merkle_tree_page(struct inode *inode,
 					       pgoff_t index,
 					       unsigned long num_ra_pages)
 {
-	DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
 	struct page *page;
 
 	index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT;
 
 	page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);
 	if (!page || !PageUptodate(page)) {
+		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
+
 		if (page)
 			put_page(page);
 		else if (num_ra_pages > 1)
diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
index 7b8f2b41c29b..c0733f867074 100644
--- a/fs/f2fs/verity.c
+++ b/fs/f2fs/verity.c
@@ -262,13 +262,14 @@ static struct page *f2fs_read_merkle_tree_page(struct inode *inode,
 					       pgoff_t index,
 					       unsigned long num_ra_pages)
 {
-	DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
 	struct page *page;
 
 	index += f2fs_verity_metadata_pos(inode) >> PAGE_SHIFT;
 
 	page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);
 	if (!page || !PageUptodate(page)) {
+		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
+
 		if (page)
 			put_page(page);
 		else if (num_ra_pages > 1)
-- 
2.35.3