Coda File System

Re: Coda and Ext3

From: Jan Harkes <>
Date: Wed, 19 Sep 2001 11:47:23 -0400
On Wed, Sep 19, 2001 at 10:23:36AM -0400, Sujal Shah wrote:
>      The Linux Coda drivers and the ext3 patches don't seem to get along
> very well, at least in Linux 2.4.7.  I've got a stock 2.4.7 kernel with
> a patch applied to the USB drivers (for a sony digital camera; see
> just a change in unusual_devs.h). 
> After I applied the ext3 patches from
> .  Basically, when an
> application tries to write to a file system mounted via coda, the
> application terminates with "Memory Fault" returned to the terminal. 
> THe file system still thinks it's busy (can't umount).

Yeah, I know, and it will probably work when you don't enable
data-journalling. Coda's kernelmodule currently uses generic_file_read
and generic_file_write on it's containerfiles, which works for many
filesystems. However, ext3fs (and tmpfs and several others) have a
filesystem specific write implementation and don't really like being
called with the generic functions.

The patch is simple, but I haven't made it yet. Basically we need to
wrap the read/write calls and call cii->c_cfile->f_op->file_write or

> loaded, however.  Also, I backed out the patches for ext3 and the
> problem went away.

ext2 uses the generic file read/write functions, so whenever ext2 is the
underlying filesystem it all works fine.

Received on 2001-09-19 11:49:04