From 2446ab6070861aba2dd9229463ffbc40016a9f33 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 1 Mar 2012 17:00:56 -0500 Subject: SUNRPC: Use RCU to dereference the rpc_clnt.cl_xprt field A migration event will replace the rpc_xprt used by an rpc_clnt. To ensure this can be done safely, all references to cl_xprt must now use a form of rcu_dereference(). Special care is taken with rpc_peeraddr2str(), which returns a pointer to memory whose lifetime is the same as the rpc_xprt. Signed-off-by: Trond Myklebust [ cel: fix lockdep splats and layering violations ] [ cel: forward ported to 3.4 ] [ cel: remove rpc_max_reqs(), add rpc_net_ns() ] Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- include/linux/sunrpc/clnt.h | 4 +++- include/linux/sunrpc/debug.h | 13 +++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'include/linux/sunrpc') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index a4c62e95c720..e3d12b4a0314 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -35,7 +35,7 @@ struct rpc_clnt { struct list_head cl_clients; /* Global list of clients */ struct list_head cl_tasks; /* List of tasks */ spinlock_t cl_lock; /* spinlock */ - struct rpc_xprt * cl_xprt; /* transport */ + struct rpc_xprt __rcu * cl_xprt; /* transport */ struct rpc_procinfo * cl_procinfo; /* procedure info */ u32 cl_prog, /* RPC program number */ cl_vers, /* RPC version number */ @@ -156,6 +156,8 @@ struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int rpc_restart_call_prepare(struct rpc_task *); int rpc_restart_call(struct rpc_task *); void rpc_setbufsize(struct rpc_clnt *, unsigned int, unsigned int); +int rpc_protocol(struct rpc_clnt *); +struct net * rpc_net_ns(struct rpc_clnt *); size_t rpc_max_payload(struct rpc_clnt *); void rpc_force_rebind(struct rpc_clnt *); size_t rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t); diff --git a/include/linux/sunrpc/debug.h b/include/linux/sunrpc/debug.h index b506936f4ce6..6cb2517bcf75 100644 --- a/include/linux/sunrpc/debug.h +++ b/include/linux/sunrpc/debug.h @@ -50,19 +50,32 @@ extern unsigned int nlm_debug; #endif #define dprintk(args...) dfprintk(FACILITY, ## args) +#define dprintk_rcu(args...) dfprintk_rcu(FACILITY, ## args) #undef ifdebug #ifdef RPC_DEBUG # define ifdebug(fac) if (unlikely(rpc_debug & RPCDBG_##fac)) + # define dfprintk(fac, args...) \ do { \ ifdebug(fac) \ printk(KERN_DEFAULT args); \ } while (0) + +# define dfprintk_rcu(fac, args...) \ + do { \ + ifdebug(fac) { \ + rcu_read_lock(); \ + printk(KERN_DEFAULT args); \ + rcu_read_unlock(); \ + } \ + } while (0) + # define RPC_IFDEBUG(x) x #else # define ifdebug(fac) if (0) # define dfprintk(fac, args...) do ; while (0) +# define dfprintk_rcu(fac, args...) do ; while (0) # define RPC_IFDEBUG(x) #endif -- cgit v1.2.3