From 7c96aef75949a56ec427fc6a2522dace2af33605 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 15 Nov 2010 11:27:01 +1100 Subject: sunrpc: remove xpt_pool The xpt_pool field is only used for reporting BUGs. And it isn't used correctly. In particular, when it is cleared in svc_xprt_received before XPT_BUSY is cleared, there is no guarantee that either the compiler or the CPU might not re-order to two assignments, just setting xpt_pool to NULL after XPT_BUSY is cleared. If a different cpu were running svc_xprt_enqueue at this moment, it might see XPT_BUSY clear and then xpt_pool non-NULL, and so BUG. This could be fixed by calling smp_mb__before_clear_bit() before the clear_bit. However as xpt_pool isn't really used, it seems safest to simply remove xpt_pool. Another alternate would be to change the clear_bit to clear_bit_unlock, and the test_and_set_bit to test_and_set_bit_lock. Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc_xprt.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/sunrpc/svc_xprt.h') diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h index aea0d438e3c7..c8f81da15c7e 100644 --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -63,7 +63,6 @@ struct svc_xprt { #define XPT_LISTENER 11 /* listening endpoint */ #define XPT_CACHE_AUTH 12 /* cache auth info */ - struct svc_pool *xpt_pool; /* current pool iff queued */ struct svc_serv *xpt_server; /* service for transport */ atomic_t xpt_reserved; /* space on outq that is rsvd */ struct mutex xpt_mutex; /* to serialize sending data */ -- cgit v1.2.3 From d75faea330dbd1873c9094e9926ae306590c0998 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 30 Nov 2010 19:15:01 -0500 Subject: rpc: move sk_bc_xprt to svc_xprt This seems obviously transport-level information even if it's currently used only by the server socket code. Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc_xprt.h | 1 + include/linux/sunrpc/svcsock.h | 1 - net/sunrpc/svcsock.c | 10 ++++++---- net/sunrpc/xprtsock.c | 2 +- 4 files changed, 8 insertions(+), 6 deletions(-) (limited to 'include/linux/sunrpc/svc_xprt.h') diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h index c8f81da15c7e..7ad9751a0d87 100644 --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -79,6 +79,7 @@ struct svc_xprt { struct list_head xpt_users; /* callbacks on free */ struct net *xpt_net; + struct rpc_xprt *xpt_bc_xprt; /* NFSv4.1 backchannel */ }; static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u) diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h index 1b353a76c304..04dba23c59f2 100644 --- a/include/linux/sunrpc/svcsock.h +++ b/include/linux/sunrpc/svcsock.h @@ -28,7 +28,6 @@ struct svc_sock { /* private TCP part */ u32 sk_reclen; /* length of record */ u32 sk_tcplen; /* current read length */ - struct rpc_xprt *sk_bc_xprt; /* NFSv4.1 backchannel xprt */ }; /* diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 52bd1130e83a..3bb400f86eae 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -987,15 +987,17 @@ static int svc_process_calldir(struct svc_sock *svsk, struct svc_rqst *rqstp, vec[0] = rqstp->rq_arg.head[0]; } else { /* REPLY */ - if (svsk->sk_bc_xprt) - req = xprt_lookup_rqst(svsk->sk_bc_xprt, xid); + struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt; + + if (bc_xprt) + req = xprt_lookup_rqst(bc_xprt, xid); if (!req) { printk(KERN_NOTICE "%s: Got unrecognized reply: " - "calldir 0x%x sk_bc_xprt %p xid %08x\n", + "calldir 0x%x xpt_bc_xprt %p xid %08x\n", __func__, ntohl(calldir), - svsk->sk_bc_xprt, xid); + bc_xprt, xid); vec[0] = rqstp->rq_arg.head[0]; goto out; } diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index dfcab5ac65af..18dc42eb5597 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2379,9 +2379,9 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args) * The backchannel uses the same socket connection as the * forechannel */ + args->bc_xprt->xpt_bc_xprt = xprt; xprt->bc_xprt = args->bc_xprt; bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt); - bc_sock->sk_bc_xprt = xprt; transport->sock = bc_sock->sk_sock; transport->inet = bc_sock->sk_sk; -- cgit v1.2.3