nfs41: exchange_id operation

Implement the exchange_id operation conforming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26

Unlike NFSv4.0, NFSv4.1 requires machine credentials. RPC_AUTH_GSS machine
credentials will be passed into the kernel at mount time to be available for
the exchange_id operation.

RPC_AUTH_UNIX root mounts can use the UNIX root credential. Store the root
credential in the nfs_client struct.

Without a credential, NFSv4.1 state renewal fails.

[nfs41: establish clientid via exchange id only if cred != NULL]
Signed-off-by: Andy Adamson<andros@umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: move nfstime4 from under CONFIG_NFS_V4_1]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: do not wait a lease time in exchange id]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: pass *session in seq_args and seq_res]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[nfs41: Ignoring impid in decode_exchange_id is missing a READ_BUF]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: fix Xcode_exchange_id's xdr Xcoding pointer type]
[nfs41: get rid of unused struct nfs41_exchange_id_res members]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index dc0feb5837b1..6f384e290753 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -48,6 +48,7 @@
 #include <linux/smp_lock.h>
 #include <linux/namei.h>
 #include <linux/mount.h>
+#include <linux/module.h>
 
 #include "nfs4_fs.h"
 #include "delegation.h"
@@ -433,11 +434,13 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
         spin_unlock(&tbl->slot_tbl_lock);
 
         slot = tbl->slots + slotid;
+        args->sa_session = session;
         args->sa_slotid = slotid;
         args->sa_cache_this = cache_reply;
 
         dprintk("<-- %s slotid=%d seqid=%d\n", __func__, slotid, slot->seq_nr);
 
+        res->sr_session = session;
         res->sr_slotid = slotid;
         res->sr_renewal_time = jiffies;
         /*
@@ -4128,6 +4131,64 @@ int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name,
 }
 
 #ifdef CONFIG_NFS_V4_1
+/*
+ * nfs4_proc_exchange_id()
+ *
+ * Since the clientid has expired, all compounds using sessions
+ * associated with the stale clientid will be returning
+ * NFS4ERR_BADSESSION in the sequence operation, and will therefore
+ * be in some phase of session reset.
+ */
+static int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
+{
+        nfs4_verifier verifier;
+        struct nfs41_exchange_id_args args = {
+                .client = clp,
+                .flags = clp->cl_exchange_flags,
+        };
+        struct nfs41_exchange_id_res res = {
+                .client = clp,
+        };
+        int status;
+        struct rpc_message msg = {
+                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_EXCHANGE_ID],
+                .rpc_argp = &args,
+                .rpc_resp = &res,
+                .rpc_cred = cred,
+        };
+        __be32 *p;
+
+        dprintk("--> %s\n", __func__);
+        BUG_ON(clp == NULL);
+        p = (u32 *)verifier.data;
+        *p++ = htonl((u32)clp->cl_boot_time.tv_sec);
+        *p = htonl((u32)clp->cl_boot_time.tv_nsec);
+        args.verifier = &verifier;
+
+        while (1) {
+                args.id_len = scnprintf(args.id, sizeof(args.id),
+                                        "%s/%s %u",
+                                        clp->cl_ipaddr,
+                                        rpc_peeraddr2str(clp->cl_rpcclient,
+                                                         RPC_DISPLAY_ADDR),
+                                        clp->cl_id_uniquifier);
+
+                status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
+
+                if (status != NFS4ERR_CLID_INUSE)
+                        break;
+
+                if (signalled())
+                        break;
+
+                if (++clp->cl_id_uniquifier == 0)
+                        break;
+        }
+
+        dprintk("<-- %s status= %d\n", __func__, status);
+        return status;
+}
+
 /* Destroy the slot table */
 static void nfs4_destroy_slot_table(struct nfs4_session *session)
 {