From 5cc83a2e5d2f3ec19462529c4144a2993b0c86e4 Mon Sep 17 00:00:00 2001 From: Marius Vollmer Date: Wed, 24 Aug 2022 14:38:48 +0300 Subject: [PATCH] mmp: don't use O_RDWR in ext2fs_mmp_read It doesn't seem to be necessary since ext2fs_mmp_write doesn't write via mmp_fd, and opening the block device with O_RDWR will trigger udev. Triggering udev is bad because it leads to an infinite loop when running dumpe2fs in response to a udev event. [ Rebased onto the maint branch, and added O_RDONLY flag. From the open(2) man page: "The argument flags must include one of the following access modes: O_RDONLY, O_WRONLY, or O_RDWR." -- TYT ] Signed-off-by: Theodore Ts'o --- lib/ext2fs/mmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c index 9ef4580..7970aac 100644 --- a/lib/ext2fs/mmp.c +++ b/lib/ext2fs/mmp.c @@ -58,7 +58,7 @@ errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf) * the MMP block by the io_manager or the VM. It needs to be fresh. */ if (fs->mmp_fd <= 0) { struct stat st; - int flags = O_RDWR | O_DIRECT; + int flags = O_RDONLY | O_DIRECT; /* * There is no reason for using O_DIRECT if we're working with -- 1.8.3.1