Re: [fuse-devel] GDB/FUSE interaction?

[Miklos S. <mi...@sz...>]

> For a long time, I've been struggling to debug an application that
> uses FUSE.  The problem is that GDB consistently crashes, just
> freezing, and providing no information about what is going on.
> Outside of GDB the application runs just fine (99.9% of the time, at
> least!)
> 
> I first encountered this problem a long time ago (when FUSE 2.5.x
> was the current version), and found that if I used an older version
> of FUSE (a 2.4.x version, I think), GDB worked fine.  Obviously, I
> should have investigated and reported the problem back then, but
> this workaround was good enough to allow me to make progress, so,
> regrettably, I didn't pursue the problem further.
> 
> Since FUSE 2.6.x came out, we modified our application to use the
> newer 2.6 interface.  The problem now, of course, is that I can't
> simply revert to an old version of FUSE for debugging.  :-(

Can you try fuse-2.7-rc1?  2.5 and 2.6 did some ugly things with
signals on exit, and that may have been the cause of the bad
interaction.  OTOH gdb _should_ handle that sort of thing.

A fuse filesystem really doesn't do anything special, it uses
perfectly ordinary read and write calls to communicate with the
kernel.

Miklos