From: Steve Wise Date: Tue, 23 Sep 2014 22:11:22 +0000 (-0500) Subject: svcrdma: advertise the correct max payload X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7e5be28827bf;p=linux-beck.git svcrdma: advertise the correct max payload Svcrdma currently advertises 1MB, which is too large. The correct value is the minimum of RPCSVC_MAXPAYLOAD and the max scatter-gather allowed in an NFSRDMA IO chunk * the host page size. This bug is usually benign because the Linux X64 NFSRDMA client correctly limits the payload size to the correct value (64*4096 = 256KB). But if the Linux client is PPC64 with a 64KB page size, then the client will indeed use a payload size that will overflow the server. Signed-off-by: Steve Wise Signed-off-by: J. Bruce Fields --- diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 374feb44afea..4e618808bc98 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -91,7 +91,7 @@ struct svc_xprt_class svc_rdma_class = { .xcl_name = "rdma", .xcl_owner = THIS_MODULE, .xcl_ops = &svc_rdma_ops, - .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, + .xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA, .xcl_ident = XPRT_TRANSPORT_RDMA, }; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index c419498b8f46..ac7fc9a31342 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -51,6 +51,7 @@ #include /* rpc_xprt */ #include /* RPC/RDMA protocol */ #include /* xprt parameters */ +#include /* RPCSVC_MAXPAYLOAD */ #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */ #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */ @@ -392,4 +393,10 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; /* Workqueue created in svc_rdma.c */ extern struct workqueue_struct *svc_rdma_wq; +#if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) +#define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD +#else +#define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) +#endif + #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */