2009-07-22 19:50:00

by Andy Adamson

[permalink] [raw]
Subject: Re: Error mounting FC8 NFS server with 2.6.31-rc3 NFSv4 client.


On Jul 21, 2009, at 5:17 PM, Trond Myklebust wrote:

> On Tue, 2009-07-21 at 11:32 -0700, Ben Greear wrote:
>> On 07/21/2009 11:28 AM, Trond Myklebust wrote:
>>> On Tue, 2009-07-21 at 11:01 -0700, Ben Greear wrote:
>>>> On 07/21/2009 10:59 AM, Trond Myklebust wrote:
>>>>> On Tue, 2009-07-21 at 10:36 -0700, Ben Greear wrote:
>>>>>> On 07/21/2009 10:12 AM, Trond Myklebust wrote:
>>>>>>> On Tue, 2009-07-21 at 09:49 -0700, Ben Greear wrote:
>>>>>>>> On 07/21/2009 05:15 AM, Trond Myklebust wrote:
>>>>>>>>
>>>>>>>>> What does /var/lib/nfs/v4recovery look like on the server?
>>>>>>>> The server was misconfigured, but I still think the client
>>>>>>>> should
>>>>>>>> behave better in this case. If you cannot reproduce it, let
>>>>>>>> me know
>>>>>>>> and I can try to be more specific. If you still want the
>>>>>>>> v4recovery
>>>>>>>> information, let me know and I'll send it.
>>>>>>> So how should the client behave, when a screwed up server
>>>>>>> allows it to
>>>>>>> mount but starts returning illegal values for setclientid? The
>>>>>>> only
>>>>>>> thing I can see we could do is to tell the user EINSANESERVER...
>>>>>> Well, it could just fail the mount and give up and not overly
>>>>>> spam
>>>>>> /var/log/messages in a tight loop perhaps?
>>>>> This doesn't happen at mount time. It happens when you open a
>>>>> file.
>>>> Not for me, and evidently not for the other person that reported
>>>> similar results. All I had to do was attempt the mount (which
>>>> never
>>>> completed).
>>>>
>>>> Thanks,
>>>> Ben
>>>
>>> Ah... You have NFS_V4_1 enabled despite the Kconfig warning...
>>> Does the
>>> bug occur when you turn this off too?
>>
>> Yes, it did.
>
> OK. The following patch should fix that particular regression.
>
> Note that there is a bug remaining inside nfs4_init_session(): we
> shouldn't be copying the rsize/wsize into the nfs_client if the latter
> was already initialised.

The rsize/wsize is copied into the session prior to the create_session
call (triggered by the state management code you moved), and is used
for session negotiation. At this point the nfs_client cl_cons_state is
set to NFS_CS_SESSION_INITING (see nfs4_alloc_session), so the
nfs_client is not initialized. The cl_cons_state is set to
NFS_CS_READY after a successful create_session call.

-->Andy

> I'm going to leave that for the moment, though,
> since that bug wasn't introduced by my patch, and it doesn't affect
> NFSv4.0.
>
> Cheers,
> Trond
> -----------------------------------------------------------------
> From: Trond Myklebust <[email protected]>
> NFSv4: Fix an NFSv4 mount regression
>
> Commit 008f55d0e019943323c20a03493a2ba5672a4cc8 (nfs41: recover
> lease in
> _nfs4_lookup_root) forces the state manager to always run on mount.
> This is
> a bug in the case of NFSv4.0, which doesn't require us to send a
> setclientid until we want to grab file state.
>
> In any case, this is completely the wrong place to be doing state
> management. Moving that code into nfs4_init_session...
>
> Signed-off-by: Trond Myklebust <[email protected]>
> ---
>
> fs/nfs/client.c | 18 +++---------------
> fs/nfs/nfs4_fs.h | 6 ++++++
> fs/nfs/nfs4proc.c | 24 +++++++++++++++++-------
> 3 files changed, 26 insertions(+), 22 deletions(-)
>
>
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index c2d0616..8d25ccb 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -1242,20 +1242,6 @@ error:
> return error;
> }
>
> -/*
> - * Initialize a session.
> - * Note: save the mount rsize and wsize for create_server
> negotiation.
> - */
> -static void nfs4_init_session(struct nfs_client *clp,
> - unsigned int wsize, unsigned int rsize)
> -{
> -#if defined(CONFIG_NFS_V4_1)
> - if (nfs4_has_session(clp)) {
> - clp->cl_session->fc_attrs.max_rqst_sz = wsize;
> - clp->cl_session->fc_attrs.max_resp_sz = rsize;
> - }
> -#endif /* CONFIG_NFS_V4_1 */
> -}
>
> /*
> * Session has been established, and the client marked ready.
> @@ -1350,7 +1336,9 @@ struct nfs_server *nfs4_create_server(const
> struct nfs_parsed_mount_data *data,
> BUG_ON(!server->nfs_client->rpc_ops);
> BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
>
> - nfs4_init_session(server->nfs_client, server->wsize, server->rsize);
> + error = nfs4_init_session(server);
> + if (error < 0)
> + goto error;
>
> /* Probe the root fh to retrieve its FSID */
> error = nfs4_path_walk(server, mntfh, data->nfs_server.export_path);
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index 61bc3a3..6ea07a3 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -220,6 +220,7 @@ extern void nfs4_destroy_session(struct
> nfs4_session *session);
> extern struct nfs4_session *nfs4_alloc_session(struct nfs_client
> *clp);
> extern int nfs4_proc_create_session(struct nfs_client *, int reset);
> extern int nfs4_proc_destroy_session(struct nfs4_session *);
> +extern int nfs4_init_session(struct nfs_server *server);
> #else /* CONFIG_NFS_v4_1 */
> static inline int nfs4_setup_sequence(struct nfs_client *clp,
> struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
> @@ -227,6 +228,11 @@ static inline int nfs4_setup_sequence(struct
> nfs_client *clp,
> {
> return 0;
> }
> +
> +static inline int nfs4_init_session(struct nfs_server *server)
> +{
> + return 0;
> +}
> #endif /* CONFIG_NFS_V4_1 */
>
> extern struct nfs4_state_maintenance_ops *nfs4_state_renewal_ops[];
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index ff0c080..df24f67 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -2040,15 +2040,9 @@ static int _nfs4_lookup_root(struct
> nfs_server *server, struct nfs_fh *fhandle,
> .rpc_argp = &args,
> .rpc_resp = &res,
> };
> - int status;
>
> nfs_fattr_init(info->fattr);
> - status = nfs4_recover_expired_lease(server);
> - if (!status)
> - status = nfs4_check_client_ready(server->nfs_client);
> - if (!status)
> - status = nfs4_call_sync(server, &msg, &args, &res, 0);
> - return status;
> + return nfs4_call_sync(server, &msg, &args, &res, 0);
> }
>
> static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh
> *fhandle,
> @@ -4793,6 +4787,22 @@ int nfs4_proc_destroy_session(struct
> nfs4_session *session)
> return status;
> }
>
> +int nfs4_init_session(struct nfs_server *server)
> +{
> + struct nfs_client *clp = server->nfs_client;
> + int ret;
> +
> + if (!nfs4_has_session(clp))
> + return 0;
> +
> + clp->cl_session->fc_attrs.max_rqst_sz = server->wsize;
> + clp->cl_session->fc_attrs.max_resp_sz = server->rsize;
> + ret = nfs4_recover_expired_lease(server);
> + if (!ret)
> + ret = nfs4_check_client_ready(clp);
> + return ret;
> +}
> +
> /*
> * Renew the cl_session lease.
> */
>
>
> --
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2009-07-22 20:20:20

by Trond Myklebust

[permalink] [raw]
Subject: Re: Error mounting FC8 NFS server with 2.6.31-rc3 NFSv4 client.

On Wed, 2009-07-22 at 15:49 -0400, Andy Adamson wrote:
> On Jul 21, 2009, at 5:17 PM, Trond Myklebust wrote:
> > Note that there is a bug remaining inside nfs4_init_session(): we
> > shouldn't be copying the rsize/wsize into the nfs_client if the latter
> > was already initialised.
>
> The rsize/wsize is copied into the session prior to the create_session
> call (triggered by the state management code you moved), and is used
> for session negotiation. At this point the nfs_client cl_cons_state is
> set to NFS_CS_SESSION_INITING (see nfs4_alloc_session), so the
> nfs_client is not initialized. The cl_cons_state is set to
> NFS_CS_READY after a successful create_session call.

The call to nfs4_init_session() is in nfs4_create_server(). It can be
called several times _after_ the nfs_client has been initialised when
you mount more than one partition from the same NFS server.

If that is the case, and if you use different rsize/wsize values on
those different mounts, then you will end up clobbering the values of
fc_attrs.max_rqst_sz, and fc_attrs.max_resp_sz, having set them to the
wsize/rsize that was set by the very last mount call.

AFAICS, what you _should_ be doing in nfs4_init_session, is something
like

if (clp->cl_session->fc_attrs.max_rqst_sz < server->wsize)
clp->cl_session->fc_attrs.max_rqst_sz = server->wsize;

Trond