Re: nfs + msdosfs = crashes & panics

[David Rhodus <drhodus@xxxxxxxxxxx>]

On Apr 13, 2004, at 9:26 PM, Matthew Dillon wrote:

> :On Tue, 13 Apr 2004 17:39:24 -0700
> :Jeffrey Hsu <hsu@xxxxxxxxxxx> wrote:
> :
> :> You're probably indirecting though a non-existent proc-related
> :> structure. The protocol threads don't have a proc structure 
> associated
> :> with them.  Before, there were a bunch of places which incorrectly
> :> used curproc to check things like credentials.   All the places
> :> are going to core dump now.  I've fixed a bunch of places which
> :> incorrectly used curthread, but there are still some left.
> :
> :I was starting to wonder if it had something to do with the struct
> :ucred... this would make sense... esp. considering it's an MS-DOS
> :filesystem... i.e., it carries no user info on files.
> :
> :FWIW, it's the same behaviour with -mapall=catseye as without (catseye
> :is the user who owns the /c directory, and mount_msdos treats that 
> user
> :as the owner of all files under it, when it's mounted.)
> :
> :-Chris
>
>     Yup, that was it.   msdosfs_write() was getting proc from
>     uio->uio_td->td_proc, but uio_td can be NULL.  In this case I just
>     conditionalized it, the proc is being used to do filesize resource
>     limit checks and I think we can safely say that we don't really 
> care
>     about that for msdosfs which stores no user cred info anyways, and
>     doubly so when accessed from an NFS server.

Interesting, has anyone tried to do an umapfs overlay with nfs ? I know
most of the people in FreeBSD find umapfs to be offensive but it is
very nice when doing UID overlays between machines using nfs.

-DR