From ba60eb25ff6be6f8e60488cdfd454e5c612bce60 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 14 Apr 2013 10:49:37 -0400 Subject: SUNRPC: Fix a livelock problem in the xprt->backlog queue This patch ensures that we throttle new RPC requests if there are requests already waiting in the xprt->backlog queue. The reason for doing this is to fix livelock issues that can occur when an existing (high priority) task is waiting in the backlog queue, gets woken up by xprt_free_slot(), but a new task then steals the slot. Signed-off-by: Trond Myklebust --- include/linux/sunrpc/xprt.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/sunrpc') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 30834be03011..12815f66a9c4 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -279,6 +279,7 @@ struct xprt_class { struct rpc_xprt *xprt_create_transport(struct xprt_create *args); void xprt_connect(struct rpc_task *task); void xprt_reserve(struct rpc_task *task); +void xprt_retry_reserve(struct rpc_task *task); int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); @@ -334,6 +335,7 @@ int xs_swapper(struct rpc_xprt *xprt, int enable); #define XPRT_CLOSING (6) #define XPRT_CONNECTION_ABORT (7) #define XPRT_CONNECTION_CLOSE (8) +#define XPRT_CONGESTED (9) static inline void xprt_set_connected(struct rpc_xprt *xprt) { -- cgit v1.2.2 From b7993cebb841b0da7a33e9d5ce301a9fd3209165 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 14 Apr 2013 11:42:00 -0400 Subject: SUNRPC: Allow rpc_create() to request that TCP slots be unlimited This is mainly for use by NFSv4.1, where the session negotiation ultimately wants to decide how many RPC slots we can fill. Signed-off-by: Trond Myklebust --- include/linux/sunrpc/clnt.h | 1 + include/linux/sunrpc/xprt.h | 3 +++ 2 files changed, 4 insertions(+) (limited to 'include/linux/sunrpc') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 2cf4ffaa3cd4..e7d492ce7c18 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -124,6 +124,7 @@ struct rpc_create_args { #define RPC_CLNT_CREATE_NOPING (1UL << 4) #define RPC_CLNT_CREATE_DISCRTRY (1UL << 5) #define RPC_CLNT_CREATE_QUIET (1UL << 6) +#define RPC_CLNT_CREATE_INFINITE_SLOTS (1UL << 7) struct rpc_clnt *rpc_create(struct rpc_create_args *args); struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *, diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 12815f66a9c4..ff5392421cb2 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -255,6 +255,8 @@ static inline int bc_prealloc(struct rpc_rqst *req) } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ +#define XPRT_CREATE_INFINITE_SLOTS (1U) + struct xprt_create { int ident; /* XPRT_TRANSPORT identifier */ struct net * net; @@ -263,6 +265,7 @@ struct xprt_create { size_t addrlen; const char *servername; struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ + unsigned int flags; }; struct xprt_class { -- cgit v1.2.2