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SUNRPC: Fix a deadlock in rpc_client_register() 

Commit 384816051c (SUNRPC: fix races on
PipeFS MOUNT notifications) introduces a regression when we call
rpc_setup_pipedir() with RPCSEC_GSS as the auth flavour.

By calling rpcauth_create() while holding the sn->pipefs_sb_lock, we
end up deadlocking in gss_pipes_dentries_create_net().
Fix is to register the client and release the mutex before calling
rpcauth_create().

Reported-by: Weston Andros Adamson <dros@netapp.com>
Tested-by: Weston Andros Adamson <dros@netapp.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: <stable@vger.kernel.org> # : 3848160: SUNRPC: fix races on PipeFS MOUNT
Cc: <stable@vger.kernel.org> # : e73f4cc: SUNRPC: split client creation
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2013-07-10 15:33:01 -04:00
parent 4f8568cb52
commit eeee245268
1 changed files with 9 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
net/sunrpc/clnt.c
View File

@ -290,7 +290,7 @@ static int rpc_client_register(const struct rpc_create_args *args,
struct rpc_auth *auth;
struct net *net = rpc_net_ns(clnt);
struct super_block *pipefs_sb;
int err = 0;
int err;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
@ -299,6 +299,10 @@ static int rpc_client_register(const struct rpc_create_args *args,
goto out;
}
rpc_register_client(clnt);
if (pipefs_sb)
rpc_put_sb_net(net);
auth = rpcauth_create(args->authflavor, clnt);
if (IS_ERR(auth)) {
dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
@ -306,16 +310,14 @@ static int rpc_client_register(const struct rpc_create_args *args,
err = PTR_ERR(auth);
goto err_auth;
}
rpc_register_client(clnt);
return 0;
err_auth:
pipefs_sb = rpc_get_sb_net(net);
__rpc_clnt_remove_pipedir(clnt);
out:
if (pipefs_sb)
rpc_put_sb_net(net);
return err;
err_auth:
__rpc_clnt_remove_pipedir(clnt);
goto out;
}
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)