Re: [PATCH][2.5.74] devfs lookup deadlock/stack corruption combined patch

[Andrew Morton <akpm@xxxxxxxx>]

Andrey Borzenkov <arvidjaar@xxxxxxx> wrote:
>
> I finally hit a painfully trivial way to reproduce another long standing 
> devfs 
> problem - deadlock between devfs_lookup and devfs_d_revalidate_wait.

uh.

> The current fix is to move re-acquire of i_sem after all 
> devfs_d_revalidate_wait waiters have been waked up.

Directory modifications appear to be under write_lock(&dir->u.dir.lock); so
that obvious problem is covered.  Your patch might introduce a race around
_devfs_get_vfs_inode() - two CPUs running that against the same inode at
the same time?

> Andrew, I slightly polished original stack corruption version to look more 
> consistent with the rest of devfs;

I think it's Lindent time.