From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: Re: [RFC PATCH 0/2] Fix up the NFS mmap code
Date: Sat, 9 Jan 2010 01:38:25 +0000 [thread overview]
Message-ID: <20100109013825.GD30528@ZenIV.linux.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.00.1001081709470.7821-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
On Fri, Jan 08, 2010 at 05:17:14PM -0800, Linus Torvalds wrote:
>
>
> On Fri, 8 Jan 2010, Trond Myklebust wrote:
> >
> > How about something like the following. I chose to wrap the call to
> > do_mmap_pgoff() instead of making a special ->pre_mmap(), since that
> > seems more consistent with the way we handle ->read() and ->write().
>
> I still don't think that you can ever do mmap _and_ readdir on the same
> inode, so there's something wrong with the lockdep annotations.
readdir() is certainly a red herring. write(), OTOH, is quite real.
And there we do i_mutex followed by pagefaults.
I *REALLY* dislike Trond's solution, though.
Could we please get a sane expalanation of the reasons why nfs mmap
wants i_mutex in the first place? Before we add yet another hook
from hell and complicate already overcomplicated area...
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: Re: [RFC PATCH 0/2] Fix up the NFS mmap code
Date: Sat, 9 Jan 2010 01:38:25 +0000 [thread overview]
Message-ID: <20100109013825.GD30528@ZenIV.linux.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.00.1001081709470.7821@localhost.localdomain>
On Fri, Jan 08, 2010 at 05:17:14PM -0800, Linus Torvalds wrote:
>
>
> On Fri, 8 Jan 2010, Trond Myklebust wrote:
> >
> > How about something like the following. I chose to wrap the call to
> > do_mmap_pgoff() instead of making a special ->pre_mmap(), since that
> > seems more consistent with the way we handle ->read() and ->write().
>
> I still don't think that you can ever do mmap _and_ readdir on the same
> inode, so there's something wrong with the lockdep annotations.
readdir() is certainly a red herring. write(), OTOH, is quite real.
And there we do i_mutex followed by pagefaults.
I *REALLY* dislike Trond's solution, though.
Could we please get a sane expalanation of the reasons why nfs mmap
wants i_mutex in the first place? Before we add yet another hook
from hell and complicate already overcomplicated area...
next prev parent reply other threads:[~2010-01-09 1:38 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-07 20:29 [GIT PULL] Please pull NFS client bugfixes Trond Myklebust
2010-01-07 21:00 ` Andi Kleen
2010-01-07 21:23 ` Peter Staubach
2010-01-07 21:35 ` Andi Kleen
2010-01-07 21:53 ` Trond Myklebust
2010-01-07 23:51 ` Andi Kleen
2010-01-08 0:14 ` Trond Myklebust
2010-01-08 0:34 ` Linus Torvalds
2010-01-08 0:45 ` Andi Kleen
2010-01-08 1:03 ` Trond Myklebust
2010-01-08 1:03 ` Trond Myklebust
2010-01-08 1:12 ` Linus Torvalds
2010-01-08 1:22 ` Trond Myklebust
2010-01-08 1:26 ` Trond Myklebust
2010-01-09 0:56 ` [RFC PATCH 0/2] Fix up the NFS mmap code Trond Myklebust
2010-01-09 0:56 ` [RFC PATCH 2/2] NFS: Fix a potential deadlock in nfs_file_mmap() Trond Myklebust
[not found] ` <20100109005624.7473.15560.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-01-09 1:54 ` Al Viro
2010-01-09 1:54 ` Al Viro
[not found] ` <20100109005624.7473.33215.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-01-09 0:56 ` [RFC PATCH 1/2] VFS: Add a mmap_file() callback to struct file_operations Trond Myklebust
2010-01-09 0:56 ` Trond Myklebust
2010-01-09 1:17 ` [RFC PATCH 0/2] Fix up the NFS mmap code Linus Torvalds
2010-01-09 1:17 ` Linus Torvalds
[not found] ` <alpine.LFD.2.00.1001081709470.7821-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-01-09 1:38 ` Al Viro [this message]
2010-01-09 1:38 ` Al Viro
2010-01-09 1:46 ` Al Viro
2010-01-09 1:57 ` Linus Torvalds
[not found] ` <alpine.LFD.2.00.1001081750080.7821-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-01-09 2:11 ` Al Viro
2010-01-09 2:11 ` Al Viro
2010-01-09 2:22 ` Linus Torvalds
[not found] ` <alpine.LFD.2.00.1001081814240.7821-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-01-09 2:30 ` Al Viro
2010-01-09 2:30 ` Al Viro
2010-01-09 2:40 ` Al Viro
2010-01-09 2:43 ` Al Viro
2010-01-10 2:00 ` Andi Kleen
2010-01-10 2:00 ` Andi Kleen
2010-01-08 1:30 ` [GIT PULL] Please pull NFS client bugfixes Linus Torvalds
2010-01-08 1:35 ` Linus Torvalds
2010-01-08 2:00 ` Linus Torvalds
2010-01-14 13:18 ` Peter Zijlstra
2010-01-08 5:19 ` Andi Kleen
2010-01-08 1:22 ` Linus Torvalds
2010-01-08 0:43 ` Andi Kleen
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