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authorJ. Bruce Fields <bfields@citi.umich.edu>2007-07-27 18:06:50 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2007-10-09 18:31:56 -0400
commit2b47eece1fa519a81c8b802af77a8b8aa44baa10 (patch)
treeb06263ca61a05cfaca7311bcfe542a44502c817c
parentc9b6cbe56d3ac471e6cd72a59ec9e324b3417016 (diff)
knfsd: spawn kernel thread to probe callback channel
We want to allow gss on the callback channel, so people using krb5 can still get the benefits of delegations. But looking up the rpc credential can take some time in that case. And we shouldn't delay the response to setclientid_confirm while we wait. It may be inefficient, but for now the simplest solution is just to spawn a new thread as necessary for the purpose. (Thanks to Adrian Bunk for catching a missing static here.) Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Cc: Adrian Bunk <bunk@kernel.org>
-rw-r--r--fs/nfsd/nfs4callback.c71
1 files changed, 34 insertions, 37 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 31d6633c7fe4..c17a5202ee3f 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -39,6 +39,7 @@
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/sched.h>
+#include <linux/kthread.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
@@ -365,6 +366,35 @@ nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
return ret;
}
+/* Reference counting, callback cleanup, etc., all look racy as heck.
+ * And why is cb_set an atomic? */
+
+static int do_probe_callback(void *data)
+{
+ struct nfs4_client *clp = data;
+ struct nfs4_callback *cb = &clp->cl_callback;
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
+ .rpc_argp = clp,
+ };
+ int status;
+
+ msg.rpc_cred = nfsd4_lookupcred(clp, 0);
+ if (IS_ERR(msg.rpc_cred))
+ goto out;
+ status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
+ put_rpccred(msg.rpc_cred);
+
+ if (status) {
+ rpc_shutdown_client(cb->cb_client);
+ cb->cb_client = NULL;
+ } else
+ atomic_set(&cb->cb_set, 1);
+out:
+ put_nfs4_client(clp);
+ return 0;
+}
+
/*
* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
*/
@@ -390,11 +420,7 @@ nfsd4_probe_callback(struct nfs4_client *clp)
.authflavor = RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
.flags = (RPC_CLNT_CREATE_NOPING),
};
- struct rpc_message msg = {
- .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
- .rpc_argp = clp,
- };
- int status;
+ struct task_struct *t;
if (atomic_read(&cb->cb_set))
return;
@@ -426,16 +452,11 @@ nfsd4_probe_callback(struct nfs4_client *clp)
/* the task holds a reference to the nfs4_client struct */
atomic_inc(&clp->cl_count);
- msg.rpc_cred = nfsd4_lookupcred(clp,0);
- if (IS_ERR(msg.rpc_cred))
- goto out_release_clp;
- status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
- put_rpccred(msg.rpc_cred);
+ t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
- if (status != 0) {
- dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
+ if (IS_ERR(t))
goto out_release_clp;
- }
+
return;
out_release_clp:
@@ -447,30 +468,6 @@ out_err:
(int)clp->cl_name.len, clp->cl_name.data);
}
-static void
-nfs4_cb_null(struct rpc_task *task, void *dummy)
-{
- struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
- struct nfs4_callback *cb = &clp->cl_callback;
- __be32 addr = htonl(cb->cb_addr);
-
- dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
-
- if (task->tk_status < 0) {
- dprintk("NFSD: callback establishment to client %.*s failed\n",
- (int)clp->cl_name.len, clp->cl_name.data);
- goto out;
- }
- atomic_set(&cb->cb_set, 1);
- dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
-out:
- put_nfs4_client(clp);
-}
-
-static const struct rpc_call_ops nfs4_cb_null_ops = {
- .rpc_call_done = nfs4_cb_null,
-};
-
/*
* called with dp->dl_count inc'ed.
* nfs4_lock_state() may or may not have been called.