linux-kernel - Re: [PATCH 0/4] Remove possible deadlocks in nfs_release

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Date:	Wed, 17 Sep 2014 09:41:13 +1000
From:	NeilBrown <neilb@...e.de>
To:	Jeff Layton <jeff.layton@...marydata.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Trond Myklebust <trond.myklebust@...marydata.com>,
	Ingo Molnar <mingo@...hat.com>, linux-fsdevel@...r.kernel.org,
	linux-mm@...ck.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/4] Remove possible deadlocks in nfs_release_page()

On Tue, 16 Sep 2014 07:47:41 -0400 Jeff Layton <jeff.layton@...marydata.com>
wrote:


> Also, we call things like invalidate_complete_page2 from the cache
> invalidation code. Will we end up with potential problems now that we
> have a stronger possibility that a page might not be freeable when it
> calls releasepage? (no idea on this -- I'm just spitballing)
> 

Answering just this part here:
 invalidate_complete_page2() is only called immediately after a call to
do_launder_page().
For nfs, that means nfs_launder_page() was called, which calls nfs_wb_page()
which in turn calls
		ret = nfs_commit_inode(inode, FLUSH_SYNC);

so the inode is fully committed when invalidate_complete_page2 is called, so
nfs_release_page will succeed.

So there shouldn't be a problem there.

Thanks,
NeilBrown

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