From f092075dd33ea04000590e8ffea65c2e7d03d764 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 21 May 2012 22:45:41 -0400 Subject: [PATCH] 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 Signed-off-by: Trond Myklebust --- fs/nfs/client.c | 2 +- fs/nfs/netns.h | 5 +++++ fs/nfs/nfs4proc.c | 14 ++++++++------ fs/nfs/nfs4xdr.c | 5 ++++- include/linux/nfs_fs_sb.h | 3 --- 5 files changed, 18 insertions(+), 11 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 9b9df71df09a..af9b7e4b9df2 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_ spin_lock_init(&clp->cl_lock); 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) idr_init(&nn->cb_ident_idr); #endif spin_lock_init(&nn->nfs_client_lock); + nn->boot_time = CURRENT_TIME; } #ifdef CONFIG_PROC_FS diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h index aa14ec303e94..8a6394edb8b0 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 */ #endif 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 81ccdbbb43e8..9e9334a172cf 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" #define NFSDBG_FACILITY NFSDBG_PROC @@ -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(;;) { rcu_read_lock(); @@ -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), "%s/%s/%u", diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index db040e971932..12b99825a1c1 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -53,9 +53,11 @@ #include #include #include + #include "nfs4_fs.h" #include "internal.h" #include "pnfs.h" +#include "netns.h" #define NFSDBG_FACILITY NFSDBG_XDR @@ -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 */ diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index 59410b365ba4..fbec57d6dc0a 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -61,9 +61,6 @@ struct nfs_client { struct rpc_wait_queue cl_rpcwaitq; - /* used for the setclientid verifier */ - struct timespec cl_boot_time; - /* idmapper */ struct idmap * cl_idmap; -- 2.20.1