On Mon, Aug 05, 2024 at 10:12:41PM GMT, Jan Kara wrote: > When the filesystem is mounted with errors=remount-ro, we were setting > SB_RDONLY flag to stop all filesystem modifications. We knew this misses > proper locking (sb->s_umount) and does not go through proper filesystem > remount procedure but it has been the way this worked since early ext2 > days and it was good enough for catastrophic situation damage > mitigation. Recently, syzbot has found a way (see link) to trigger > warnings in filesystem freezing because the code got confused by > SB_RDONLY changing under its hands. Since these days we set > EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all > filesystem modifications, modifying SB_RDONLY shouldn't be needed. So > stop doing that. > > Link: https://lore.kernel.org/all/000000000000b90a8e061e21d12f@xxxxxxxxxx > Reported-by: Christian Brauner <brauner@xxxxxxxxxx> > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- Thank you! Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
