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 <bfields@xxxxxxxxxxxxxx>
---
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 efb85ca..378ce9b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1318,7 +1318,7 @@ 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);
--
1.6.3.3
--
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