From: "J. Bruce Fields" <bfields@fieldses.org>
To: "J. Bruce Fields" <bfields@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>, linux-nfs@vger.kernel.org
Subject: Re: nfsd4 xdr encoding fixes v2
Date: Thu, 22 May 2014 15:17:50 -0400 [thread overview]
Message-ID: <20140522191750.GA25423@fieldses.org> (raw)
In-Reply-To: <20140513213321.GG5222@fieldses.org>
On Tue, May 13, 2014 at 05:33:21PM -0400, J. Bruce Fields wrote:
> On Tue, May 13, 2014 at 05:18:41PM -0400, bfields wrote:
> > On Tue, May 13, 2014 at 10:48:26AM -0400, J. Bruce Fields wrote:
> > > On Tue, May 13, 2014 at 04:09:45AM -0700, Christoph Hellwig wrote:
> > > > On Mon, May 12, 2014 at 09:11:28AM -0700, Christoph Hellwig wrote:
> > > > > On Mon, May 12, 2014 at 12:07:41PM -0400, J. Bruce Fields wrote:
> > > > > > On Mon, May 12, 2014 at 01:20:59AM -0700, Christoph Hellwig wrote:
> > > > > > > This series seem to cause hangs during xfstests against a server on the
> > > > > > > same VM. The trace is fairly similar every the hang happens, but the
> > > > > > > point at which it happens differs:
> > > > > >
> > > > > > Ouch, OK, and you're sure it starts with this series?
> > > > > >
> > > > > > I guess I should try to replicate it here. Might take a copule days.
> > > >
> > > > Seems lile "nfsd4: allow exotic read compounds" is the culprit.
> > >
> > > OK, it makes sense that the problem would be there. Looking....
> >
> > I got xfstests set up and can reproduce some problems (a hang, the
> > nfs4svc_encode_compoundres WARN, and some allocation failures), though
> > not exactly what you reported.
> >
> > I also notice that commit ("nfsd4: allow exotic read compounds") has a
> > lot of extraneous cleanup that I should split out.
>
> In fact, the change to handle multiple reads per compound *should* only
> affect the nfsd4_encode_readv() case. Whereas you're probably
> exercising only the nfsd4_encode_splice_read() case. So probably some
> of the extraneous cleanup in that patch is bogus.
Yes, this removal:
- xdr->page_ptr += (maxcount + PAGE_SIZE - 1) / PAGE_SIZE;
buried in that cleanup is bogus and seems like it could result in
freeing a page twice. I've fixed that and split the confusing "cleanup"
out into separate patches. I can't get any hangs by running xfstests
any more.
On the other hand, I never saw exactly what you did, so more testing
wouldn't hurt.
I'll send out a v3 soon.
--b.
prev parent reply other threads:[~2014-05-22 19:18 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-11 20:52 nfsd4 xdr encoding fixes v2 J. Bruce Fields
2014-05-11 20:52 ` [PATCH 01/43] nfsd4: embed xdr_stream in nfsd4_compoundres J. Bruce Fields
2014-05-12 5:34 ` Christoph Hellwig
2014-05-16 9:58 ` Kinglong Mee
2014-05-22 15:13 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 02/43] nfsd4: tweak nfsd4_encode_getattr to take xdr_stream J. Bruce Fields
2014-05-12 5:35 ` Christoph Hellwig
2014-05-12 16:06 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 03/43] nfsd4: move proc_compound xdr encode init to helper J. Bruce Fields
2014-05-12 5:36 ` Christoph Hellwig
2014-05-11 20:52 ` [PATCH 04/43] nfsd4: reserve head space for krb5 integ/priv info J. Bruce Fields
2014-05-12 5:37 ` Christoph Hellwig
2014-05-12 21:45 ` J. Bruce Fields
2014-05-13 5:05 ` Christoph Hellwig
2014-05-13 14:47 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 05/43] nfsd4: move nfsd4_operation to xdr4.h J. Bruce Fields
2014-05-12 5:41 ` Christoph Hellwig
2014-05-22 15:56 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 06/43] nfsd4: fix encoding of out-of-space replies J. Bruce Fields
2014-05-12 8:18 ` Christoph Hellwig
2014-05-12 21:47 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 07/43] nfsd4: allow space for final error return J. Bruce Fields
2014-05-12 8:18 ` Christoph Hellwig
2014-05-12 14:06 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 08/43] nfsd4: use xdr_reserve_space in attribute encoding J. Bruce Fields
2014-05-11 20:52 ` [PATCH 09/43] nfsd4: use xdr_stream throughout compound encoding J. Bruce Fields
2014-05-11 20:52 ` [PATCH 10/43] nfsd4: remove ADJUST_ARGS J. Bruce Fields
2014-05-11 20:52 ` [PATCH 11/43] nfsd4: no need for encode_compoundres to adjust lengths J. Bruce Fields
2014-05-11 20:52 ` [PATCH 12/43] nfsd4: keep xdr buf length updated J. Bruce Fields
2014-05-11 20:52 ` [PATCH 13/43] rpc: xdr_truncate_encode J. Bruce Fields
2014-05-11 20:52 ` [PATCH 14/43] nfsd4: use xdr_truncate_encode J. Bruce Fields
2014-05-11 20:52 ` [PATCH 15/43] nfsd4: "backfill" using write_bytes_to_xdr_buf J. Bruce Fields
2014-05-11 20:52 ` [PATCH 16/43] nfsd4: teach encoders to handle reserve_space failures J. Bruce Fields
2014-05-11 20:52 ` [PATCH 17/43] nfsd4: reserve space before inlining 0-copy pages J. Bruce Fields
2014-05-11 20:52 ` [PATCH 18/43] nfsd4: nfsd4_check_resp_size needn't recalculate length J. Bruce Fields
2014-05-11 20:52 ` [PATCH 19/43] nfsd4: remove redundant encode buffer size checking J. Bruce Fields
2014-05-11 20:52 ` [PATCH 20/43] nfsd4: size-checking cleanup J. Bruce Fields
2014-05-11 20:52 ` [PATCH 21/43] nfsd4: allow encoding across page boundaries J. Bruce Fields
2014-05-11 20:52 ` [PATCH 22/43] nfsd4: convert 4.1 replay encoding J. Bruce Fields
2014-05-11 20:52 ` [PATCH 23/43] nfsd4: don't try to encode conflicting owner if low on space J. Bruce Fields
2014-05-11 20:52 ` [PATCH 24/43] nfsd4: more precise nfsd4_max_reply J. Bruce Fields
2014-05-11 20:52 ` [PATCH 25/43] nfsd4: minor encode_read cleanup J. Bruce Fields
2014-05-11 20:52 ` [PATCH 26/43] nfsd4: nfsd4_check_resp_size should check against whole buffer J. Bruce Fields
2014-05-11 20:52 ` [PATCH 27/43] rpc: define xdr_restrict_buflen J. Bruce Fields
2014-05-11 20:52 ` [PATCH 28/43] nfsd4: adjust buflen to session channel limit J. Bruce Fields
2014-05-11 20:52 ` [PATCH 29/43] nfsd4: use session limits to release send buffer reservation J. Bruce Fields
2014-05-11 20:52 ` [PATCH 30/43] nfsd4: allow large readdirs J. Bruce Fields
2014-05-11 20:52 ` [PATCH 31/43] nfsd4: enforce rd_dircount J. Bruce Fields
2014-05-11 20:52 ` [PATCH 32/43] nfsd4: don't treat readlink like a zero-copy operation J. Bruce Fields
2014-05-11 20:52 ` [PATCH 33/43] nfsd4: better estimate of getattr response size J. Bruce Fields
2014-05-11 20:52 ` [PATCH 34/43] nfsd4: estimate sequence " J. Bruce Fields
2014-05-11 20:52 ` [PATCH 35/43] nfsd4: turn off zero-copy-read in exotic cases J. Bruce Fields
2014-05-11 20:52 ` [PATCH 36/43] nfsd4: nfsd_vfs_read doesn't use file handle parameter J. Bruce Fields
2014-05-11 20:52 ` [PATCH 37/43] nfsd4: separate splice and readv cases J. Bruce Fields
2014-05-11 20:52 ` [PATCH 38/43] nfsd4: allow exotic read compounds J. Bruce Fields
2014-05-11 20:52 ` [PATCH 39/43] nfsd4: really fix nfs4err_resource in 4.1 case J. Bruce Fields
2014-05-12 5:33 ` Christoph Hellwig
2014-05-12 14:18 ` J. Bruce Fields
2014-05-11 20:52 ` [PATCH 40/43] nfsd4: kill WRITE32 J. Bruce Fields
2014-05-11 20:52 ` [PATCH 41/43] nfsd4: kill WRITE64 J. Bruce Fields
2014-05-11 20:52 ` [PATCH 42/43] nfsd4: kill WRITEMEM J. Bruce Fields
2014-05-11 20:52 ` [PATCH 43/43] nfsd4: kill write32, write64 J. Bruce Fields
2014-05-12 8:20 ` nfsd4 xdr encoding fixes v2 Christoph Hellwig
2014-05-12 16:07 ` J. Bruce Fields
2014-05-12 16:11 ` Christoph Hellwig
2014-05-13 11:09 ` Christoph Hellwig
2014-05-13 14:48 ` J. Bruce Fields
2014-05-13 21:18 ` J. Bruce Fields
2014-05-13 21:33 ` J. Bruce Fields
2014-05-22 19:17 ` J. Bruce Fields [this message]
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