* [PATCH] nfs: RPC_MAX_AUTH_SIZE is in bytes
@ 2017-09-20 16:42 J. Bruce Fields
2017-09-20 16:49 ` J. Bruce Fields
0 siblings, 1 reply; 4+ messages in thread
From: J. Bruce Fields @ 2017-09-20 16:42 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
From: "J. Bruce Fields" <bfields@redhat.com>
The units of RPC_MAX_AUTH_SIZE is bytes, not 4-byte words. This causes
the client to request a larger-than-necessary session replay slot size.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/nfs/nfs4xdr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 37c8af003275..14ed9791ec9c 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1842,8 +1842,8 @@ static void encode_create_session(struct xdr_stream *xdr,
* Assumes OPEN is the biggest non-idempotent compound.
* 2 is the verifier.
*/
- max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE +
- RPC_MAX_AUTH_SIZE + 2) * XDR_UNIT;
+ max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE + 2)
+ * XDR_UNIT + RPC_MAX_AUTH_SIZE;
encode_op_hdr(xdr, OP_CREATE_SESSION, decode_create_session_maxsz, hdr);
p = reserve_space(xdr, 16 + 2*28 + 20 + clnt->cl_nodelen + 12);
--
2.13.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] nfs: RPC_MAX_AUTH_SIZE is in bytes
2017-09-20 16:42 [PATCH] nfs: RPC_MAX_AUTH_SIZE is in bytes J. Bruce Fields
@ 2017-09-20 16:49 ` J. Bruce Fields
2017-09-20 16:56 ` Chuck Lever
0 siblings, 1 reply; 4+ messages in thread
From: J. Bruce Fields @ 2017-09-20 16:49 UTC (permalink / raw)
To: Trond Myklebust, Anna Schumaker; +Cc: linux-nfs
On Wed, Sep 20, 2017 at 12:42:13PM -0400, bfields wrote:
> From: "J. Bruce Fields" <bfields@redhat.com>
>
> The units of RPC_MAX_AUTH_SIZE is bytes, not 4-byte words. This causes
> the client to request a larger-than-necessary session replay slot size.
By the way, the client's still asking for 3428 bytes after that, which
seems high. It's mostly the fault of NFS4_MAXLABELLEN, which is 2048.
I haven't spotted an improvement there yet.
Noticed because knfsd was hitting session drc cache limits much to early
and failing CREATE_SESSION (hence mount). The main trouble is on the
server side, so I'm relaxing the limits there (and revisiting Trond's
dynamic slot renegotiation patches). But I thought I should check for
any easy improvements here too.
--b.
>
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
> fs/nfs/nfs4xdr.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index 37c8af003275..14ed9791ec9c 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -1842,8 +1842,8 @@ static void encode_create_session(struct xdr_stream *xdr,
> * Assumes OPEN is the biggest non-idempotent compound.
> * 2 is the verifier.
> */
> - max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE +
> - RPC_MAX_AUTH_SIZE + 2) * XDR_UNIT;
> + max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE + 2)
> + * XDR_UNIT + RPC_MAX_AUTH_SIZE;
>
> encode_op_hdr(xdr, OP_CREATE_SESSION, decode_create_session_maxsz, hdr);
> p = reserve_space(xdr, 16 + 2*28 + 20 + clnt->cl_nodelen + 12);
> --
> 2.13.5
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] nfs: RPC_MAX_AUTH_SIZE is in bytes
2017-09-20 16:49 ` J. Bruce Fields
@ 2017-09-20 16:56 ` Chuck Lever
2017-09-20 18:15 ` J. Bruce Fields
0 siblings, 1 reply; 4+ messages in thread
From: Chuck Lever @ 2017-09-20 16:56 UTC (permalink / raw)
To: J. Bruce Fields; +Cc: Trond Myklebust, Anna Schumaker, Linux NFS Mailing List
> On Sep 20, 2017, at 12:49 PM, J. Bruce Fields <bfields@fieldses.org> wrote:
>
> On Wed, Sep 20, 2017 at 12:42:13PM -0400, bfields wrote:
>> From: "J. Bruce Fields" <bfields@redhat.com>
>>
>> The units of RPC_MAX_AUTH_SIZE is bytes, not 4-byte words. This causes
>> the client to request a larger-than-necessary session replay slot size.
>
> By the way, the client's still asking for 3428 bytes after that, which
> seems high. It's mostly the fault of NFS4_MAXLABELLEN, which is 2048.
The maximum size of NFSv4 LOOKUP replies is also quite large, thanks
to label support (IIRC). It would be nicer for NFS/RDMA, at least, if
the maximum reply sizes of common operations were small (say, less
than 1024 bytes).
> I haven't spotted an improvement there yet.
I haven't either.
> Noticed because knfsd was hitting session drc cache limits much to early
> and failing CREATE_SESSION (hence mount). The main trouble is on the
> server side, so I'm relaxing the limits there (and revisiting Trond's
> dynamic slot renegotiation patches). But I thought I should check for
> any easy improvements here too.
>
> --b.
>
>>
>> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
>> ---
>> fs/nfs/nfs4xdr.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
>> index 37c8af003275..14ed9791ec9c 100644
>> --- a/fs/nfs/nfs4xdr.c
>> +++ b/fs/nfs/nfs4xdr.c
>> @@ -1842,8 +1842,8 @@ static void encode_create_session(struct xdr_stream *xdr,
>> * Assumes OPEN is the biggest non-idempotent compound.
>> * 2 is the verifier.
>> */
>> - max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE +
>> - RPC_MAX_AUTH_SIZE + 2) * XDR_UNIT;
>> + max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE + 2)
>> + * XDR_UNIT + RPC_MAX_AUTH_SIZE;
>>
>> encode_op_hdr(xdr, OP_CREATE_SESSION, decode_create_session_maxsz, hdr);
>> p = reserve_space(xdr, 16 + 2*28 + 20 + clnt->cl_nodelen + 12);
>> --
>> 2.13.5
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Chuck Lever
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] nfs: RPC_MAX_AUTH_SIZE is in bytes
2017-09-20 16:56 ` Chuck Lever
@ 2017-09-20 18:15 ` J. Bruce Fields
0 siblings, 0 replies; 4+ messages in thread
From: J. Bruce Fields @ 2017-09-20 18:15 UTC (permalink / raw)
To: Chuck Lever; +Cc: Trond Myklebust, Anna Schumaker, Linux NFS Mailing List
On Wed, Sep 20, 2017 at 12:56:07PM -0400, Chuck Lever wrote:
>
> > On Sep 20, 2017, at 12:49 PM, J. Bruce Fields <bfields@fieldses.org> wrote:
> >
> > On Wed, Sep 20, 2017 at 12:42:13PM -0400, bfields wrote:
> >> From: "J. Bruce Fields" <bfields@redhat.com>
> >>
> >> The units of RPC_MAX_AUTH_SIZE is bytes, not 4-byte words. This causes
> >> the client to request a larger-than-necessary session replay slot size.
> >
> > By the way, the client's still asking for 3428 bytes after that, which
> > seems high. It's mostly the fault of NFS4_MAXLABELLEN, which is 2048.
>
> The maximum size of NFSv4 LOOKUP replies is also quite large, thanks
> to label support (IIRC). It would be nicer for NFS/RDMA, at least, if
> the maximum reply sizes of common operations were small (say, less
> than 1024 bytes).
>
>
> > I haven't spotted an improvement there yet.
>
> I haven't either.
Session (and I assume RDMA) limits have to be negotiated pretty early,
before we know server capabilities. And even if we renegotiated
later--I think security label support is per-filesystem, while the
connection parameters are server-wide.
So, I dunno, all I can think of is putting off fetching the security
label till it's needed, but maybe that's not practical--I don't know
where it's used.
Well, whatever, we can live with it.
--b.
>
>
> > Noticed because knfsd was hitting session drc cache limits much to early
> > and failing CREATE_SESSION (hence mount). The main trouble is on the
> > server side, so I'm relaxing the limits there (and revisiting Trond's
> > dynamic slot renegotiation patches). But I thought I should check for
> > any easy improvements here too.
> >
> > --b.
> >
> >>
> >> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> >> ---
> >> fs/nfs/nfs4xdr.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> >> index 37c8af003275..14ed9791ec9c 100644
> >> --- a/fs/nfs/nfs4xdr.c
> >> +++ b/fs/nfs/nfs4xdr.c
> >> @@ -1842,8 +1842,8 @@ static void encode_create_session(struct xdr_stream *xdr,
> >> * Assumes OPEN is the biggest non-idempotent compound.
> >> * 2 is the verifier.
> >> */
> >> - max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE +
> >> - RPC_MAX_AUTH_SIZE + 2) * XDR_UNIT;
> >> + max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE + 2)
> >> + * XDR_UNIT + RPC_MAX_AUTH_SIZE;
> >>
> >> encode_op_hdr(xdr, OP_CREATE_SESSION, decode_create_session_maxsz, hdr);
> >> p = reserve_space(xdr, 16 + 2*28 + 20 + clnt->cl_nodelen + 12);
> >> --
> >> 2.13.5
> >>
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> Chuck Lever
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2017-09-20 18:15 ` J. Bruce Fields
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