Date: Thu, 12 Mar 2009 13:21:15 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Eric Dumazet <dada1@cosmosbay.com>
Cc: jmoyer@redhat.com, avi@redhat.com, linux-aio@kvack.org,
       zach.brown@oracle.com, bcrl@kvack.org, linux-kernel@vger.kernel.org,
       davidel@xmailserver.org, cl@linux-foundation.org
Subject: Re: [PATCH] fs: fput() can be called from interrupt context
Message-Id: <20090312132115.21b478cd.akpm@linux-foundation.org>
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On Thu, 12 Mar 2009 20:22:06 +0100
Eric Dumazet <dada1@cosmosbay.com> wrote:

> > It's somewhat encouraging that we're apparently already doing fput()
> > from within keventd (although how frequently?).  There might be
> > problems with file locking, security code, etc from doing fput() from
> > an unexpected thread.  And then there are all the usual weird problem
> > with using the keventd queues which take a long time to get discovered.
> > 
> 
> Hum... Do you mean "if (in_interrupt())" is not the right test to
> perform ? 

No, in_interrupt() seems appropriate.

It's a bit weak, because it means that the proposed code can't be used
for calling fput() inside spinlock.  A better interface would be to
add a new fput_atomic() and let the caller decide which functions
should be called, depending upon what context the caller is running in.


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