From: "J. Bruce Fields" Subject: [PATCH 11/11] nfsd4: allow 4.0 clients to change callback path Date: Tue, 9 Mar 2010 19:28:16 -0500 Message-ID: <1268180896-30921-12-git-send-email-bfields@citi.umich.edu> References: <1268180896-30921-1-git-send-email-bfields@citi.umich.edu> <1268180896-30921-2-git-send-email-bfields@citi.umich.edu> <1268180896-30921-3-git-send-email-bfields@citi.umich.edu> <1268180896-30921-4-git-send-email-bfields@citi.umich.edu> <1268180896-30921-5-git-send-email-bfields@citi.umich.edu> <1268180896-30921-6-git-send-email-bfields@citi.umich.edu> <1268180896-30921-7-git-send-email-bfields@citi.umich.edu> <1268180896-30921-8-git-send-email-bfields@citi.umich.edu> <1268180896-30921-9-git-send-email-bfields@citi.umich.edu> <1268180896-30921-10-git-send-email-bfields@citi.umich.edu> <1268180896-30921-11-git-send-email-bfields@citi.umich.edu> Cc: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Return-path: Received: from fieldses.org ([174.143.236.118]:42181 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755751Ab0CJA0v (ORCPT ); Tue, 9 Mar 2010 19:26:51 -0500 In-Reply-To: <1268180896-30921-11-git-send-email-bfields@citi.umich.edu> Sender: linux-nfs-owner@vger.kernel.org List-ID: The rfc allows a client to change the callback parameters, but we didn't previously implement it. Teach the callbacks to rerun themselves (by placing themselves on a workqueue) when they recognize that their rpc task has been killed and that the callback connection has changed. Then we can change the callback connection by setting up a new rpc client, modifying the nfs4 client to point at it, waiting for any work in progress to complete, and then shutting down the old client. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4callback.c | 26 +++++++++++++++++++------- fs/nfsd/nfs4state.c | 7 +++---- fs/nfsd/state.h | 2 +- 3 files changed, 23 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 1d83ac6..151ea90 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -457,9 +457,8 @@ static int max_cb_time(void) /* Reference counting, callback cleanup, etc., all look racy as heck. * And why is cl_cb_set an atomic? */ -int setup_callback_client(struct nfs4_client *clp, struct svc_xprt *cb_xprt) +int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *cb, struct svc_xprt *cb_xprt) { - struct nfs4_cb_conn *cb = &clp->cl_cb_conn; struct rpc_timeout timeparms = { .to_initval = max_cb_time(), .to_retries = 0, @@ -491,7 +490,7 @@ int setup_callback_client(struct nfs4_client *clp, struct svc_xprt *cb_xprt) PTR_ERR(client)); return PTR_ERR(client); } - clp->cl_cb_client = client; + nfsd4_set_callback_client(clp, client); return 0; } @@ -549,13 +548,13 @@ void do_probe_callback(struct nfs4_client *clp) * Set up the callback client and put a NFSPROC4_CB_NULL on the wire... */ void -nfsd4_probe_callback(struct nfs4_client *clp, struct svc_xprt *cb_xprt) +nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *cb, struct svc_xprt *cb_xprt) { int status; BUG_ON(atomic_read(&clp->cl_cb_set)); - status = setup_callback_client(clp, cb_xprt); + status = setup_callback_client(clp, cb, cb_xprt); if (status) { warn_no_callback_path(clp, status); return; @@ -645,18 +644,32 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata) } } + static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) { struct nfs4_delegation *dp = calldata; struct nfs4_client *clp = dp->dl_client; + struct rpc_clnt *current_rpc_client = clp->cl_cb_client; nfsd4_cb_done(task, calldata); + if (current_rpc_client == NULL) { + /* We're shutting down; give up. */ + /* XXX: err, or is it ok just to fall through + * and rpc_restart_call? */ + return; + } + switch (task->tk_status) { case -EIO: /* Network partition? */ atomic_set(&clp->cl_cb_set, 0); warn_no_callback_path(clp, task->tk_status); + if (current_rpc_client != task->tk_client) { + /* queue a callback on the new connection: */ + nfsd4_cb_recall(dp); + return; + } case -EBADHANDLE: case -NFS4ERR_BAD_STATEID: /* Race: client probably got cb_recall @@ -705,8 +718,7 @@ void nfsd4_destroy_callback_queue(void) destroy_workqueue(callback_wq); } -void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt -*new) +void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt *new) { struct rpc_clnt *old = clp->cl_cb_client; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 89efd5e..d71d59c 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1314,7 +1314,7 @@ nfsd4_create_session(struct svc_rqst *rqstp, cstate->minorversion; unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog; unconf->cl_cb_seq_nr = 1; - nfsd4_probe_callback(unconf, rqstp->rq_xprt); + nfsd4_probe_callback(unconf, &unconf->cl_cb_conn, rqstp->rq_xprt); } conf = unconf; } else { @@ -1601,9 +1601,8 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, if (!same_creds(&conf->cl_cred, &unconf->cl_cred)) status = nfserr_clid_inuse; else { - /* XXX: We just turn off callbacks until we can handle - * change request correctly. */ atomic_set(&conf->cl_cb_set, 0); + nfsd4_probe_callback(conf, &unconf->cl_cb_conn, NULL); expire_client(unconf); status = nfs_ok; @@ -1637,7 +1636,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, } move_to_confirmed(unconf); conf = unconf; - nfsd4_probe_callback(conf, NULL); + nfsd4_probe_callback(conf, &conf->cl_cb_conn, NULL); status = nfs_ok; } } else if ((!conf || (conf && !same_verf(&conf->cl_confirm, &confirm))) diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 8ecba4a..3b0e088 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -389,7 +389,7 @@ extern int nfs4_in_grace(void); extern __be32 nfs4_check_open_reclaim(clientid_t *clid); extern void nfs4_free_stateowner(struct kref *kref); extern int set_callback_cred(void); -extern void nfsd4_probe_callback(struct nfs4_client *clp, struct svc_xprt *); +extern void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *, struct svc_xprt *); extern void nfsd4_do_callback_rpc(struct work_struct *); extern void nfsd4_cb_recall(struct nfs4_delegation *dp); extern int nfsd4_create_callback_queue(void); -- 1.6.3.3