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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-03-01 23:00:56 +0100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-03-02 21:36:38 +0100 |
| commit | 2446ab6070861aba2dd9229463ffbc40016a9f33 (patch) | |
| tree | 2e366c3236788936b9f4f58c0787ae01c265f4a4 /net/sunrpc/stats.c | |
| parent | NFS: Add debugging messages to NFSv4's CLOSE procedure (diff) | |
| download | linux-2446ab6070861aba2dd9229463ffbc40016a9f33.tar.xz linux-2446ab6070861aba2dd9229463ffbc40016a9f33.zip | |
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 <Trond.Myklebust@netapp.com>
[ 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 <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/stats.c')
| -rw-r--r-- | net/sunrpc/stats.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c index 1eb3304bc105..bc2068ee795b 100644 --- a/net/sunrpc/stats.c +++ b/net/sunrpc/stats.c @@ -22,6 +22,7 @@ #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/svcsock.h> #include <linux/sunrpc/metrics.h> +#include <linux/rcupdate.h> #include "netns.h" @@ -179,7 +180,7 @@ static void _print_name(struct seq_file *seq, unsigned int op, void rpc_print_iostats(struct seq_file *seq, struct rpc_clnt *clnt) { struct rpc_iostats *stats = clnt->cl_metrics; - struct rpc_xprt *xprt = clnt->cl_xprt; + struct rpc_xprt *xprt; unsigned int op, maxproc = clnt->cl_maxproc; if (!stats) @@ -189,8 +190,11 @@ void rpc_print_iostats(struct seq_file *seq, struct rpc_clnt *clnt) seq_printf(seq, "p/v: %u/%u (%s)\n", clnt->cl_prog, clnt->cl_vers, clnt->cl_protname); + rcu_read_lock(); + xprt = rcu_dereference(clnt->cl_xprt); if (xprt) xprt->ops->print_stats(xprt, seq); + rcu_read_unlock(); seq_printf(seq, "\tper-op statistics\n"); for (op = 0; op < maxproc; op++) { |