path: root/fs
diff options
authorChuck Lever <chuck.lever@oracle.com>2012-05-21 22:45:41 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-05-22 16:45:46 -0400
commitf092075dd33ea04000590e8ffea65c2e7d03d764 (patch)
tree626ce6b85084d50e9d2d81e32850e494eadbc8cb /fs
parent2c820d9a97f07b273b2c8a5960bd52b1b5864c68 (diff)
NFS: Always use the same SETCLIENTID boot verifier
Currently our NFS client assigns a unique SETCLIENTID boot verifier for each server IP address it knows about. It's set to CURRENT_TIME when the struct nfs_client for that server IP is created. During the SETCLIENTID operation, our client also presents an nfs_client_id4 string to servers, as an identifier on which the server can hang all of this client's NFSv4 state. Our client's nfs_client_id4 string is unique for each server IP address. An NFSv4 server is obligated to wipe all NFSv4 state associated with an nfs_client_id4 string when the client presents the same nfs_client_id4 string along with a changed SETCLIENTID boot verifier. When our client unmounts the last of a server's shares, it destroys that server's struct nfs_client. The next time the client mounts that NFS server, it creates a fresh struct nfs_client with a fresh boot verifier. On seeing the fresh verifer, the server wipes any previous NFSv4 state associated with that nfs_client_id4. However, NFSv4.1 clients are supposed to present the same nfs_client_id4 string to all servers. And, to support Transparent State Migration, the same nfs_client_id4 string should be presented to all NFSv4.0 servers so they recognize that migrated state for this client belongs with state a server may already have for this client. (This is known as the Uniform Client String model). If the nfs_client_id4 string is the same but the boot verifier changes for each server IP address, SETCLIENTID and EXCHANGE_ID operations from such a client could unintentionally result in a server wiping a client's previously obtained lease. Thus, if our NFS client is going to use a fixed nfs_client_id4 string, either for NFSv4.0 or NFSv4.1 mounts, our NFS client should use a boot verifier that does not change depending on server IP address. Replace our current per-nfs_client boot verifier with a per-nfs_net boot verifier. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
4 files changed, 18 insertions, 8 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 9b9df71df09..af9b7e4b9df 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -184,7 +184,6 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
- clp->cl_boot_time = CURRENT_TIME;
clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
clp->cl_minorversion = cl_init->minorversion;
clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
@@ -1813,6 +1812,7 @@ void nfs_clients_init(struct net *net)
+ nn->boot_time = CURRENT_TIME;
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index aa14ec303e9..8a6394edb8b 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -1,3 +1,7 @@
+ * NFS-private data for each "struct net". Accessed with net_generic().
+ */
#ifndef __NFS_NETNS_H__
#define __NFS_NETNS_H__
@@ -20,6 +24,7 @@ struct nfs_net {
struct idr cb_ident_idr; /* Protected by nfs_client_lock */
spinlock_t nfs_client_lock;
+ struct timespec boot_time;
extern int nfs_net_id;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 81ccdbbb43e..9e9334a172c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -64,6 +64,7 @@
#include "iostat.h"
#include "callback.h"
#include "pnfs.h"
+#include "netns.h"
@@ -3903,8 +3904,8 @@ wait_on_recovery:
return -EAGAIN;
-static void nfs4_construct_boot_verifier(struct nfs_client *clp,
- nfs4_verifier *bootverf)
+static void nfs4_init_boot_verifier(const struct nfs_client *clp,
+ nfs4_verifier *bootverf)
__be32 verf[2];
@@ -3914,8 +3915,9 @@ static void nfs4_construct_boot_verifier(struct nfs_client *clp,
verf[0] = 0;
verf[1] = (__be32)(NSEC_PER_SEC + 1);
} else {
- verf[0] = (__be32)clp->cl_boot_time.tv_sec;
- verf[1] = (__be32)clp->cl_boot_time.tv_nsec;
+ struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+ verf[0] = (__be32)nn->boot_time.tv_sec;
+ verf[1] = (__be32)nn->boot_time.tv_nsec;
memcpy(bootverf->data, verf, sizeof(bootverf->data));
@@ -3939,7 +3941,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
int loop = 0;
int status;
- nfs4_construct_boot_verifier(clp, &sc_verifier);
+ nfs4_init_boot_verifier(clp, &sc_verifier);
for(;;) {
@@ -5099,7 +5101,7 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
dprintk("--> %s\n", __func__);
BUG_ON(clp == NULL);
- nfs4_construct_boot_verifier(clp, &verifier);
+ nfs4_init_boot_verifier(clp, &verifier);
args.id_len = scnprintf(args.id, sizeof(args.id),
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index db040e97193..12b99825a1c 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -53,9 +53,11 @@
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include "nfs4_fs.h"
#include "internal.h"
#include "pnfs.h"
+#include "netns.h"
@@ -1702,6 +1704,7 @@ static void encode_create_session(struct xdr_stream *xdr,
char machine_name[NFS4_MAX_MACHINE_NAME_LEN];
uint32_t len;
struct nfs_client *clp = args->client;
+ struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
u32 max_resp_sz_cached;
@@ -1743,7 +1746,7 @@ static void encode_create_session(struct xdr_stream *xdr,
*p++ = cpu_to_be32(RPC_AUTH_UNIX); /* auth_sys */
/* authsys_parms rfc1831 */
- *p++ = cpu_to_be32((u32)clp->cl_boot_time.tv_nsec); /* stamp */
+ *p++ = (__be32)nn->boot_time.tv_nsec; /* stamp */
p = xdr_encode_opaque(p, machine_name, len);
*p++ = cpu_to_be32(0); /* UID */
*p++ = cpu_to_be32(0); /* GID */