Date: Wed, 17 Sep 2014 09:41:13 +1000
From: NeilBrown <neilb@suse.de>
To: Jeff Layton <jeff.layton@primarydata.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Trond Myklebust <trond.myklebust@primarydata.com>,
        Ingo Molnar <mingo@redhat.com>, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-nfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/4] Remove possible deadlocks in nfs_release_page()
Message-ID: <20140917094113.0cb07cf1@notabene.brown>
In-Reply-To: <20140916074741.1de870c5@tlielax.poochiereds.net>
References: <20140916051911.22257.24658.stgit@notabene.brown>
	<20140916074741.1de870c5@tlielax.poochiereds.net>
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On Tue, 16 Sep 2014 07:47:41 -0400 Jeff Layton <jeff.layton@primarydata.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)
>=20

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 =3D 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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