Re: [PATCH] Fix inconsistent lock state in inotify

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 15 Apr 2009 13:59:29 +0200
Luca Tettamanti <kronos.it@gmail.com> wrote:

> >> +++ b/fs/notify/inotify/inotify_user.c
> >> @@ -220,7 +220,7 @@ static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
> >>                               rem = 0;
> >>               }
> >>
> >> -             kevent->name = kmalloc(len + rem, GFP_KERNEL);
> >> +             kevent->name = kmalloc(len + rem, GFP_NOFS);
> >>               if (unlikely(!kevent->name)) {
> >>                       kmem_cache_free(event_cachep, kevent);
> >>                       return NULL;
> >
> > Thanks.
> >
> > This is in fact a false positive and we plan to fix it via lockdep
> > annotation.
> 
> Well, I trust you on the "false positive", but a few line before there this:
> 
>   kevent = kmem_cache_alloc(event_cachep, GFP_NOFS);
> 
> so can kmem_cache_alloc also use GFP_KERNEL?

Yes, it looks that way.

umm, I think I'll merge your original patch as a reminder-to-self.
If the problem doesn't get fixed in a better way for 2.6.30 then I
might end up going with the GFP_NOFS approach.

But it's bad to weaken the memory allocation mode just to plug a lockdep
warning.