From 43a498e938887956f393b5e45ea6ac79cc5f4b84 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 15 Jun 2023 00:17:01 -0400 Subject: [PATCH] resize2fs: use Direct I/O when reading the superblock for online resizes If the file system is mounted, the superblock can be changing while resize2fs is trying to read the superblock, resulting in checksum failures. One way of avoiding this problem is read the superblock using Direct I/O, since the kernel makes sure that what gets written to disk is self-consistent. Suggested-by: Krister Johansen Signed-off-by: Theodore Ts'o Signed-off-by: Pavel Reichl --- resize/main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/resize/main.c b/resize/main.c index 94f5ec6d..f914c050 100644 --- a/resize/main.c +++ b/resize/main.c @@ -403,6 +403,8 @@ if (!(mount_flags & EXT2_MF_MOUNTED)) io_flags = EXT2_FLAG_RW | EXT2_FLAG_EXCLUSIVE; + if (mount_flags & EXT2_MF_MOUNTED) + io_flags |= EXT2_FLAG_DIRECT_IO; io_flags |= EXT2_FLAG_64BITS; if (undo_file) { -- 2.48.1