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>
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 0e0865e..1bb2972 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -8,6 +8,7 @@
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/slab.h>
+#include <linux/rcupdate.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
@@ -33,7 +34,7 @@
res->bitmap[0] = res->bitmap[1] = 0;
res->status = htonl(NFS4ERR_BADHANDLE);
- dprintk("NFS: GETATTR callback request from %s\n",
+ dprintk_rcu("NFS: GETATTR callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
inode = nfs_delegation_find_inode(cps->clp, &args->fh);
@@ -73,7 +74,7 @@
if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
goto out;
- dprintk("NFS: RECALL callback request from %s\n",
+ dprintk_rcu("NFS: RECALL callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
res = htonl(NFS4ERR_BADHANDLE);
@@ -533,7 +534,7 @@
if (!cps->clp) /* set in cb_sequence */
goto out;
- dprintk("NFS: RECALL_ANY callback request from %s\n",
+ dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
status = cpu_to_be32(NFS4ERR_INVAL);
@@ -568,7 +569,7 @@
if (!cps->clp) /* set in cb_sequence */
goto out;
- dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
+ dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
args->crsa_target_max_slots);