From: "J. Bruce Fields" <bfields@fieldses.org>
To: Scott Mayhew <smayhew@redhat.com>
Cc: chuck.lever@oracle.com, linux-nfs@vger.kernel.org
Subject: Re: [PATCH] nfsd4: fix up replay_matches_cache()
Date: Wed, 9 Oct 2019 15:51:21 -0400 [thread overview]
Message-ID: <20191009195121.GA23703@fieldses.org> (raw)
In-Reply-To: <20191009191137.28007-1-smayhew@redhat.com>
On Wed, Oct 09, 2019 at 03:11:37PM -0400, Scott Mayhew wrote:
> When running an nfs stress test, I see quite a few cached replies that
> don't match up with the actual request. The first comment in
> replay_matches_cache() makes sense, but the code doesn't seem to
> match... fix it.
Thanks, I'll apply. But I'm curious whether you're seeing any practical
impact from this? I don't think it should matter.
--b.
>
> Fixes: 53da6a53e1d4 ("nfsd4: catch some false session retries")
> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
> ---
> fs/nfsd/nfs4state.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index c65aeaa812d4..08f6eb2b73f8 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -3548,12 +3548,17 @@ static bool replay_matches_cache(struct svc_rqst *rqstp,
> (bool)seq->cachethis)
> return false;
> /*
> - * If there's an error than the reply can have fewer ops than
> - * the call. But if we cached a reply with *more* ops than the
> - * call you're sending us now, then this new call is clearly not
> - * really a replay of the old one:
> + * If there's an error then the reply can have fewer ops than
> + * the call.
> */
> - if (slot->sl_opcnt < argp->opcnt)
> + if (slot->sl_opcnt < argp->opcnt && !slot->sl_status)
> + return false;
> + /*
> + * But if we cached a reply with *more* ops than the call you're
> + * sending us now, then this new call is clearly not really a
> + * replay of the old one:
> + */
> + if (slot->sl_opcnt > argp->opcnt)
> return false;
> /* This is the only check explicitly called by spec: */
> if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))
> --
> 2.17.2
next prev parent reply other threads:[~2019-10-09 19:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-09 19:11 [PATCH] nfsd4: fix up replay_matches_cache() Scott Mayhew
2019-10-09 19:51 ` J. Bruce Fields [this message]
2019-10-09 20:19 ` Scott Mayhew
2019-10-09 20:33 ` J. Bruce Fields
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