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	Sat, 13 Feb 2016 12:47:44 -0500
Date: Sat, 13 Feb 2016 17:47:38 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Mike Marshall <hubcap@omnibond.com>
Cc: Martin Brandenburg <martin@omnibond.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: Orangefs ABI documentation
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On Sat, Feb 13, 2016 at 12:18:12PM -0500, Mike Marshall wrote:
> I added the patches, and ran a bunch of tests.
> 
> Stuff works fine when left unbothered, and also
> when wrenches are thrown into the works.
> 
> I had multiple userspace things going on at the
> same time, dbench, ls -R, find... kill -9 or control-C on
> any of them is handled well. When I killed both
> the client-core and its restarter, the kernel
> dealt with swarm of ops that had nowhere
> to go... the WARN_ON in service_operation
> was hit.
> 
> Feb 12 16:19:12 be1 kernel: [ 3658.167544] orangefs: please confirm
> that pvfs2-client daemon is running.
> Feb 12 16:19:12 be1 kernel: [ 3658.167547] fs/orangefs/dir.c line 264:
> orangefs_readdir: orangefs_readdir_index_get() failure (-5)

I.e. bufmap is gone.

> Feb 12 16:19:12 be1 kernel: [ 3658.170741] ------------[ cut here ]------------
> Feb 12 16:19:12 be1 kernel: [ 3658.170746] WARNING: CPU: 0 PID: 1667
> at fs/orangefs/waitqueue.c:203 service_operation+0x4f6/0x7f0()

... and we are in wait_for_direct_io(), holding an r/w slot and finding
ourselves with bufmap already gone, despite not having freed that slot
yet.  Bloody wonderful - we still have bufmap refcounting buggered somewhere.

Which tree had that been?  Could you push that tree (having checked that
you don't have any uncommitted changes) in some branch?