From:   "inoguchi.yuki@fujitsu.com" <inoguchi.yuki@fujitsu.com>
To:     "'bfields@fieldses.org'" <bfields@fieldses.org>
CC:     'Trond Myklebust' <trondmy@hammerspace.com>,
        "'linux-nfs@vger.kernel.org'" <linux-nfs@vger.kernel.org>,
        "'neilb@suse.de'" <neilb@suse.de>,
        "'mbenjami@redhat.com'" <mbenjami@redhat.com>
Subject: RE: client caching and locks
Thread-Topic: client caching and locks
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Date:   Thu, 6 Jan 2022 07:23:16 +0000
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> How about this?  I also updated the lock/nolock description and deleted
> the end of this subsection since it's redundant with that. And removed
> the bit about using nolock to mount /var with v2/v3 as that seems like a
> bit of a niche case at this point.  If we still want to document that, I
> think it belongs elsewhere.

Thank you so much for creating the patch!

For the most part I agree with you, but I feel unsafe to remove the part=20
"using nolock to mount /var with v2/v3" even if it seems niche case.=20
I'm also not sure if there is another suitable document to migrate it.=20

Therefore, at the end of "lock/nolock" subsection ...

> @@ -733,16 +733,9 @@ but such locks provide exclusion only against other
> applications
>  running on the same client.
>  Remote applications are not affected by these locks.
>  .IP
> -NLM locking must be disabled with the
> -.B nolock
> -option when using NFS to mount
> -.I /var
> -because
> -.I /var
> -contains files used by the NLM implementation on Linux.
> -Using the
> +The
>  .B nolock
> -option is also required when mounting exports on NFS servers
> +option is required when using NFSv2 or NFSv3 to mount servers
>  that do not support the NLM protocol.
>  .TP 1.5i
>  .BR cto " / " nocto

... can we keep the description like this ?
-----
@@ -733,17 +733,14 @@ but such locks provide exclusion only against other a=
pplications
 running on the same client.
 Remote applications are not affected by these locks.
 .IP
-NLM locking must be disabled with the
+When using NFSv2 or NFSv3, the
 .B nolock
-option when using NFS to mount
-.I /var
-because
+option is required to mount servers that do not support the NLM protocol,
+or to mount
 .I /var
+because
+.I /var
 contains files used by the NLM implementation on Linux.
-Using the
-.B nolock
-option is also required when mounting exports on NFS servers
-that do not support the NLM protocol.
 .TP 1.5i
 .BR cto " / " nocto
 Selects whether to use close-to-open cache coherence semantics.
-----
Yuki Inoguchi