Re: [MC] [CHECKER] Do ext2, jfs and reiserfs respect mount -o sync/dirsync option?

[Andrew Morton <akpm@osdl.org>]

Junfeng Yang <yjf@stanford.edu> wrote:
>
> On Thu, 3 Mar 2005, Junfeng Yang wrote:
> 
> >
> > Hi,
> >
> > FiSC (our file system checker) emits several warnings on ext2, jfs and
> > reiserfs, complaining that diretories or files are lost while FiSC
> > believes they should already be persistent on disk. (ext3 behaves
> > correctly.)
> 
> I forget to mention, we are mainly looking for crash-recovery bugs.  The
> warnings can trigger this way:
> 1. do several file system operations
> 2. "crash" the test machine
> 3. get the crashed disk image, run fsck to recover
> 4. mount the recovered disk image
>
> I'm able to reproduce the same warnings on ext2 using the following
> program:
> 
> main()
> {
>         system("sudo umount /dev/hda9");
>         system("/sbin/mke2fs /dev/hda9");
>         system("sudo mount -t ext2 /dev/hda9 /mnt/sbd1 -o sync,dirsync");
>         creat("/mnt/sbd1/0002", 0777);
>         mkdir("/mnt/sbd1/0003", 0777);
> 	// unplug your power cord here :)  then use e2fsck to recover
> }

That would be a bug.  Please send the e2fsck output.

> uname -a shows
> Linux notus 2.6.8-1-686 #1 Thu Nov 25 04:34:30 UTC 2004 i686 GNU/Linux

It would be much better to test vaguely contemporary kernels.