nfsd: fix spurious EACCESS in reconnect_path()
[safe/jmp/linux-2.6] / fs / nfsd / nfs4callback.c
index 31d6633..0b3ffa9 100644 (file)
@@ -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>
@@ -103,7 +104,7 @@ xdr_writemem(__be32 *p, const void *ptr, int nbytes)
 } while (0)
 #define RESERVE_SPACE(nbytes)   do {                            \
        p = xdr_reserve_space(xdr, nbytes);                     \
-       if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
+       if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
        BUG_ON(!p);                                             \
 } while (0)
 
@@ -133,7 +134,7 @@ xdr_error:                                      \
        p = xdr_inline_decode(xdr, nbytes); \
        if (!p) { \
                dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
-                       __FUNCTION__, __LINE__); \
+                       __func__, __LINE__); \
                return -EIO; \
        } \
 } while (0)
@@ -343,34 +344,27 @@ static struct rpc_version *       nfs_cb_version[] = {
        &nfs_cb_version4,
 };
 
-/*
- * Use the SETCLIENTID credential
- */
-static struct rpc_cred *
-nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
-{
-        struct auth_cred acred;
-       struct rpc_clnt *clnt = clp->cl_callback.cb_client;
-       struct rpc_cred *ret;
-
-        get_group_info(clp->cl_cred.cr_group_info);
-        acred.uid = clp->cl_cred.cr_uid;
-        acred.gid = clp->cl_cred.cr_gid;
-        acred.group_info = clp->cl_cred.cr_group_info;
-
-        dprintk("NFSD:     looking up %s cred\n",
-                clnt->cl_auth->au_ops->au_name);
-        ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
-        put_group_info(clp->cl_cred.cr_group_info);
-        return ret;
-}
+static struct rpc_program cb_program;
 
-/*
- * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
- */
-void
-nfsd4_probe_callback(struct nfs4_client *clp)
+static struct rpc_stat cb_stats = {
+               .program        = &cb_program
+};
+
+#define NFS4_CALLBACK 0x40000000
+static struct rpc_program cb_program = {
+               .name           = "nfs4_cb",
+               .number         = NFS4_CALLBACK,
+               .nrvers         = ARRAY_SIZE(nfs_cb_version),
+               .version        = nfs_cb_version,
+               .stats          = &cb_stats,
+};
+
+/* 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 sockaddr_in      addr;
        struct nfs4_callback    *cb = &clp->cl_callback;
        struct rpc_timeout      timeparms = {
@@ -379,97 +373,78 @@ nfsd4_probe_callback(struct nfs4_client *clp)
                .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
                .to_exponential = 1,
        };
-       struct rpc_program *    program = &cb->cb_program;
        struct rpc_create_args args = {
                .protocol       = IPPROTO_TCP,
                .address        = (struct sockaddr *)&addr,
                .addrsize       = sizeof(addr),
                .timeout        = &timeparms,
-               .program        = program,
+               .program        = &cb_program,
                .version        = nfs_cb_version[1]->number,
-               .authflavor     = RPC_AUTH_UNIX,        /* XXX: need AUTH_GSS... */
+               .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,
        };
+       struct rpc_clnt *client;
        int status;
 
-       if (atomic_read(&cb->cb_set))
-               return;
-
        /* Initialize address */
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(cb->cb_port);
        addr.sin_addr.s_addr = htonl(cb->cb_addr);
 
-       /* Initialize rpc_program */
-       program->name = "nfs4_cb";
-       program->number = cb->cb_prog;
-       program->nrvers = ARRAY_SIZE(nfs_cb_version);
-       program->version = nfs_cb_version;
-       program->stats = &cb->cb_stat;
-
        /* Initialize rpc_stat */
-       memset(program->stats, 0, sizeof(cb->cb_stat));
-       program->stats->program = program;
+       memset(args.program->stats, 0, sizeof(struct rpc_stat));
 
        /* Create RPC client */
-       cb->cb_client = rpc_create(&args);
-       if (IS_ERR(cb->cb_client)) {
+       client = rpc_create(&args);
+       if (IS_ERR(client)) {
                dprintk("NFSD: couldn't create callback client\n");
+               status = PTR_ERR(client);
                goto out_err;
        }
 
-       /* 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);
+       status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
 
-       if (status != 0) {
-               dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
-               goto out_release_clp;
-       }
-       return;
+       if (status)
+               goto out_release_client;
 
-out_release_clp:
-       atomic_dec(&clp->cl_count);
-       rpc_shutdown_client(cb->cb_client);
+       cb->cb_client = client;
+       atomic_set(&cb->cb_set, 1);
+       put_nfs4_client(clp);
+       return 0;
+out_release_client:
+       rpc_shutdown_client(client);
 out_err:
-       cb->cb_client = NULL;
+       put_nfs4_client(clp);
        dprintk("NFSD: warning: no callback path to client %.*s\n",
                (int)clp->cl_name.len, clp->cl_name.data);
+       return status;
 }
 
-static void
-nfs4_cb_null(struct rpc_task *task, void *dummy)
+/*
+ * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
+ */
+void
+nfsd4_probe_callback(struct nfs4_client *clp)
 {
-       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);
+       struct task_struct *t;
 
-       dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
+       BUG_ON(atomic_read(&clp->cl_callback.cb_set));
 
-       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);
-}
+       /* the task holds a reference to the nfs4_client struct */
+       atomic_inc(&clp->cl_count);
 
-static const struct rpc_call_ops nfs4_cb_null_ops = {
-       .rpc_call_done = nfs4_cb_null,
-};
+       t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
+
+       if (IS_ERR(t))
+               atomic_dec(&clp->cl_count);
+
+       return;
+}
 
 /*
  * called with dp->dl_count inc'ed.
@@ -488,13 +463,6 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
        int retries = 1;
        int status = 0;
 
-       if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
-               return;
-
-       msg.rpc_cred = nfsd4_lookupcred(clp, 0);
-       if (IS_ERR(msg.rpc_cred))
-               goto out;
-
        cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
        cbr->cbr_dp = dp;
 
@@ -503,6 +471,7 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
                switch (status) {
                        case -EIO:
                                /* Network partition? */
+                               atomic_set(&clp->cl_callback.cb_set, 0);
                        case -EBADHANDLE:
                        case -NFS4ERR_BAD_STATEID:
                                /* Race: client probably got cb_recall
@@ -515,13 +484,11 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
                status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
        }
 out_put_cred:
-       put_rpccred(msg.rpc_cred);
-out:
-       if (status == -EIO)
-               atomic_set(&clp->cl_callback.cb_set, 0);
-       /* Success or failure, now we're either waiting for lease expiration
-        * or deleg_return. */
-       dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
+       /*
+        * Success or failure, now we're either waiting for lease expiration
+        * or deleg_return.
+        */
+       put_nfs4_client(clp);
        nfs4_put_delegation(dp);
        return;
 }