[PATCH 6.18.y 1/2] f2fs: remove non-uptodate folio from the page cache in move_data_block

[Sasha Levin <sashal@kernel.org>]

From: Yongpeng Yang <yangyongpeng@xiaomi.com>

[ Upstream commit 9609dd704725a40cd63d915f2ab6c44248a44598 ]

During data movement, move_data_block acquires file folio without
triggering a file read. Such folio are typically not uptodate, they need
to be removed from the page cache after gc complete. This patch marks
folio with the PG_dropbehind flag and uses folio_end_dropbehind to
remove folio from the page cache.

Signed-off-by: Yunlei He <heyunlei@xiaomi.com>
Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: e0288584baa5 ("f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/gc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 3d9f326ae840ad..c7f6312cbb1016 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1456,7 +1456,11 @@ static int move_data_block(struct inode *inode, block_t bidx,
 put_out:
 	f2fs_put_dnode(&dn);
 out:
-	f2fs_folio_put(folio, true);
+	if (!folio_test_uptodate(folio))
+		__folio_set_dropbehind(folio);
+	folio_unlock(folio);
+	folio_end_dropbehind(folio);
+	folio_put(folio);
 	return err;
 }
 
-- 
2.53.0