Re: is there a way to export a fat32 file system using nfs?

[Neil Brown]

On Tuesday June 12, [e-mail] wrote:
> Hi.  I seem to remember  that at one time in the 2.2 series I was able
> to to export fat32 file systems using nfs, but now it doesn't work
> anymore.

No, it doesn't.

It did in early 2.2 due to some fairly ugly hacks which just had to
go.  They worked in a lot of simple cases, but it wouldn't be too
difficult to confuse such a server so that it would start losing files.

It would be possible to add to 2.4.5, but not easy.
The basic problem is that you cannot create a reliable NFS filehandle
for a file in a FAT filesystem as there are no inode numbers or
anything similar.

What might work would be:

 In fat_fill_inode, set i_generation to the current time.

 When creating a filehandle, store:
    i_ino
    i_generation
    i_location
    i_logstart

 When when asked to lookup a filehandle:
   Call find_inode(i_ino).  
    If this finds something check i_generation.
    If it matches, SUCCESS.

   Call fat_iget(i_location).
    If this finds something, check i_logstart. 
    If it matches, assume SUCCESS.

   Then comes the tricky bit:  read the directory entry
    indicated by i_location, check the i_logstart is right,
    if it is, try to get it into the inode cache properly.
    
It is something that I would like to do, but I have lots of other
things that I want to do at the moment.

NeilBrown

> 
> If I remember correctly, I get "get: operation not permitted" when
> trying to export the directory in question.
> 
> I am using 2.4.5.
> 
> Any assistance would be appreciated.
> 
> -- 
>          John Covici
>          [e-mail]
> 
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