linux-kernel - [PATCH] f2fs: fix to map blocks correctly for direct read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20241031102200.440407-1-chao@kernel.org>
Date: Thu, 31 Oct 2024 18:22:00 +0800
From: Chao Yu <chao@...nel.org>
To: jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org,
	Chao Yu <chao@...nel.org>,
	kernel test robot <oliver.sang@...el.com>,
	Cyril Hrubis <chrubis@...e.cz>
Subject: [PATCH] f2fs: fix to map blocks correctly for direct read

f2fs_map_blocks() supports to map continuous holes or preallocated
address, we should avoid setting F2FS_MAP_MAPPED for these cases
only, otherwise, it may fail f2fs_iomap_begin(), and make direct
write fallbacking to use buffered IO and flush, result in performance
regression.

Fixes: 9f0f6bf42714 ("f2fs: support to map continuous holes or preallocated address")
Reported-by: kernel test robot <oliver.sang@...el.com>
Closes: https://lore.kernel.org/oe-lkp/202409122103.e45aa13b-oliver.sang@intel.com
Cc: Cyril Hrubis <chrubis@...e.cz>
Signed-off-by: Chao Yu <chao@...nel.org>
---
 fs/f2fs/data.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 306b86b0595d..38b85160c6bd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1676,7 +1676,12 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag)
 		/* reserved delalloc block should be mapped for fiemap. */
 		if (blkaddr == NEW_ADDR)
 			map->m_flags |= F2FS_MAP_DELALLOC;
-		if (flag != F2FS_GET_BLOCK_DIO || !is_hole)
+		/*
+		 * f2fs_map_blocks() supports to map continuous holes or
+		 * preallocated address, don't set F2FS_MAP_MAPPED for these
+		 * cases only.
+		 */
+		if (flag != F2FS_GET_BLOCK_DIO || map->m_may_create || !is_hole)
 			map->m_flags |= F2FS_MAP_MAPPED;
 
 		map->m_pblk = blkaddr;
-- 
2.40.1