From 4b21d0defcc9680da8a694e92d5fe8eb668c2c0b Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Sun, 7 Mar 2010 23:39:01 -0500 Subject: [PATCH] nfsd4: allow 4.0 clients to change callback path 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 | 29 ++++++++++++++++++++--------- fs/nfsd/nfs4state.c | 7 +++---- fs/nfsd/state.h | 2 +- 3 files changed, 24 insertions(+), 14 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index d6c46a9..ea77aa6 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) +int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *cb) { - struct nfs4_cb_conn *cb = &clp->cl_cb_conn; struct rpc_timeout timeparms = { .to_initval = max_cb_time(), .to_retries = 0, @@ -481,7 +480,7 @@ int setup_callback_client(struct nfs4_client *clp) if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) return -EINVAL; if (cb->cb_minorversion) { - args.bc_xprt = clp->cl_cb_conn.cb_xprt; + args.bc_xprt = cb->cb_xprt; args.protocol = XPRT_TRANSPORT_BC_TCP; } /* Create RPC client */ @@ -491,7 +490,7 @@ int setup_callback_client(struct nfs4_client *clp) PTR_ERR(client)); return PTR_ERR(client); } - clp->cl_cb_client = client; + nfsd4_set_callback_client(clp, client); return 0; } @@ -548,14 +547,13 @@ 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) +void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *cb) { int status; BUG_ON(atomic_read(&clp->cl_cb_set)); - status = setup_callback_client(clp); + status = setup_callback_client(clp, cb); if (status) { warn_no_callback_path(clp, status); return; @@ -645,18 +643,32 @@ 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 +717,7 @@ 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 59c9bd4..4300d9f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1312,7 +1312,7 @@ 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); + nfsd4_probe_callback(unconf, &unconf->cl_cb_conn); } conf = unconf; } else { @@ -1605,9 +1605,8 @@ 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); expire_client(unconf); status = nfs_ok; @@ -1641,7 +1640,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, } move_to_confirmed(unconf); conf = unconf; - nfsd4_probe_callback(conf); + nfsd4_probe_callback(conf, &conf->cl_cb_conn); 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 cf43812..98836fd 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -390,7 +390,7 @@ 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); +extern void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *); 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); -- 1.8.2.3