From eeee245268c951262b861bc1be4e9dc812352499 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 10 Jul 2013 15:33:01 -0400 Subject: [PATCH] SUNRPC: Fix a deadlock in rpc_client_register() Commit 384816051ca9125cd54750e59c780c2a2655fa4f (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 Tested-by: Weston Andros Adamson Cc: Stanislav Kinsbursky Cc: # : 3848160: SUNRPC: fix races on PipeFS MOUNT Cc: # : e73f4cc: SUNRPC: split client creation Signed-off-by: Trond Myklebust --- net/sunrpc/clnt.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index f0339ae9bf37..aa401560777b 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -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) -- 2.20.1