2010-06-17 23:01:30

by Benny Halevy

Subject: [PATCH] SQUASHME: pnfsd: setup backchannel in create_session also in session reestablishment

The client may send an EXCHANGE_ID and a following CREATE_SESSION for an
existing clientid. In this case we'll find the nfs4_client in the confirmed
list.

Signed-off-by: Benny Halevy <[email protected]>
---
fs/nfsd/nfs4state.c | 24 +++++++++++-------------
1 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3e012d4..0df5483 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1405,25 +1405,23 @@ nfsd4_create_session(struct svc_rqst *rqstp,
if (is_ds_only_session(unconf->cl_exchange_flags))
cr_ses->flags &= ~SESSION4_BACK_CHAN;

- if (cr_ses->flags & SESSION4_BACK_CHAN) {
- unconf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
- svc_xprt_get(rqstp->rq_xprt);
- rpc_copy_addr(
- (struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
- sa);
- unconf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
- unconf->cl_cb_conn.cb_minorversion =
- cstate->minorversion;
- unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
- unconf->cl_cb_seq_nr = 1;
- nfsd4_probe_callback(unconf, &unconf->cl_cb_conn);
- }
conf = unconf;
} else {
status = nfserr_stale_clientid;
goto out;
}

+ if (cr_ses->flags & SESSION4_BACK_CHAN) {
+ conf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
+ svc_xprt_get(rqstp->rq_xprt);
+ rpc_copy_addr((struct sockaddr *)&conf->cl_cb_conn.cb_addr, sa);
+ conf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
+ conf->cl_cb_conn.cb_minorversion = cstate->minorversion;
+ conf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
+ conf->cl_cb_seq_nr = 1;
+ nfsd4_probe_callback(conf, &conf->cl_cb_conn);
+ }
+
/*
* We do not support RDMA or persistent sessions
*/
--
1.6.4.4

2010-06-26 15:24:48

by J.Bruce Fields

Subject: Re: [PATCH] SQUASHME: pnfsd: setup backchannel in create_session also in session reestablishment

On Thu, Jun 17, 2010 at 07:01:36PM -0400, Benny Halevy wrote:
> The client may send an EXCHANGE_ID and a following CREATE_SESSION for an
> existing clientid. In this case we'll find the nfs4_client in the confirmed
> list.

This changes callback information on a client after the client may
already have callbacks in progress. I think there will be races.

I have a partial attempt at fixing this at:

git://linux-nfs.org/~bfields/linux-topics.git callbacks

--b.

>
> Signed-off-by: Benny Halevy <[email protected]>
> ---
> fs/nfsd/nfs4state.c | 24 +++++++++++-------------
> 1 files changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 3e012d4..0df5483 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1405,25 +1405,23 @@ nfsd4_create_session(struct svc_rqst *rqstp,
> if (is_ds_only_session(unconf->cl_exchange_flags))
> cr_ses->flags &= ~SESSION4_BACK_CHAN;
>
> - if (cr_ses->flags & SESSION4_BACK_CHAN) {
> - unconf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
> - svc_xprt_get(rqstp->rq_xprt);
> - rpc_copy_addr(
> - (struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
> - sa);
> - unconf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
> - unconf->cl_cb_conn.cb_minorversion =
> - cstate->minorversion;
> - unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
> - unconf->cl_cb_seq_nr = 1;
> - nfsd4_probe_callback(unconf, &unconf->cl_cb_conn);
> - }
> conf = unconf;
> } else {
> status = nfserr_stale_clientid;
> goto out;
> }
>
> + if (cr_ses->flags & SESSION4_BACK_CHAN) {
> + conf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
> + svc_xprt_get(rqstp->rq_xprt);
> + rpc_copy_addr((struct sockaddr *)&conf->cl_cb_conn.cb_addr, sa);
> + conf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
> + conf->cl_cb_conn.cb_minorversion = cstate->minorversion;
> + conf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
> + conf->cl_cb_seq_nr = 1;
> + nfsd4_probe_callback(conf, &conf->cl_cb_conn);
> + }
> +
> /*
> * We do not support RDMA or persistent sessions
> */
> --
> 1.6.4.4

2010-06-18 21:55:55

by Benny Halevy

Subject: Re: [PATCH] SQUASHME: pnfsd: setup backchannel in create_session also in session reestablishment

Bruce, this patch should go upstream.

Thanks,

Benny

On Jun. 17, 2010, 19:01 -0400, Benny Halevy <[email protected]> wrote:
> The client may send an EXCHANGE_ID and a following CREATE_SESSION for an
> existing clientid. In this case we'll find the nfs4_client in the confirmed
> list.
>
> Signed-off-by: Benny Halevy <[email protected]>
> ---
> fs/nfsd/nfs4state.c | 24 +++++++++++-------------
> 1 files changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 3e012d4..0df5483 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1405,25 +1405,23 @@ nfsd4_create_session(struct svc_rqst *rqstp,
> if (is_ds_only_session(unconf->cl_exchange_flags))
> cr_ses->flags &= ~SESSION4_BACK_CHAN;
>
> - if (cr_ses->flags & SESSION4_BACK_CHAN) {
> - unconf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
> - svc_xprt_get(rqstp->rq_xprt);
> - rpc_copy_addr(
> - (struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
> - sa);
> - unconf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
> - unconf->cl_cb_conn.cb_minorversion =
> - cstate->minorversion;
> - unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
> - unconf->cl_cb_seq_nr = 1;
> - nfsd4_probe_callback(unconf, &unconf->cl_cb_conn);
> - }
> conf = unconf;
> } else {
> status = nfserr_stale_clientid;
> goto out;
> }
>
> + if (cr_ses->flags & SESSION4_BACK_CHAN) {
> + conf->cl_cb_conn.cb_xprt = rqstp->rq_xprt;
> + svc_xprt_get(rqstp->rq_xprt);
> + rpc_copy_addr((struct sockaddr *)&conf->cl_cb_conn.cb_addr, sa);
> + conf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
> + conf->cl_cb_conn.cb_minorversion = cstate->minorversion;
> + conf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
> + conf->cl_cb_seq_nr = 1;
> + nfsd4_probe_callback(conf, &conf->cl_cb_conn);
> + }
> +
> /*
> * We do not support RDMA or persistent sessions
> */