From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Lameter <cl@linux-foundation.org>
Subject: Re: SLUB defrag pull request?
Date: Mon, 13 Oct 2008 09:35:18 -0700
Message-ID: <48F378C6.7030206@linux-foundation.org>
References: <1223883004.31587.15.camel@penberg-laptop> <1223883164.31587.16.camel@penberg-laptop> <Pine.LNX.4.64.0810131227120.20511@blonde.site> <200810132354.30789.nickpiggin@yahoo.com.au> <E1KpNwq-0003OW-8f@pomaz-ex.szeredi.hu> <E1KpOOL-0003Vf-9y@pomaz-ex.szeredi.hu>
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To: Miklos Szeredi <miklos@szeredi.hu>
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Miklos Szeredi wrote:
> And the things kick_inodes() does without any sort of locking look
> even more dangerous.
>
> It should be the other way round: first make sure nothing is
> referencing the inode, and _then_ start cleaning it up with
> appropriate locks held.  See prune_icache().
>
>   
kick_inodes() only works on inodes that first have undergone 
get_inodes() where we establish a refcount under inode_lock(). The final 
cleanup in kick_inodes() is done under iprune_mutex. You are looking at 
the loop that does writeback and invalidates attached dentries. This can 
fail for various reasons.