On Fri, Oct 03, 2008 at 04:33:48PM -0500, Tom Tucker wrote:
> Add a log message that allows the administrator to determine if server memory
> is exposed on a particular client connection. This message can be disabled
> by writing 0 to the /proc/sys/sunrpc/svc_rdma/show_conn_info file.
I could grudgingly live with the idea of a log message here as a
temporary fix while we figure out something better, but I'm not happy
about making it bigger and adding a sysctl.
If we just want a hack for now, I'd be inclined to leave this printk a
dprintk, add the extra information to the dprintk, and tell people to
turn on transport debugging and watch a client connect. Ugly, but at
least it'll be obvious it's not an api that's going to stick around.
Beyond the short-term: is there some other way of getting this
information from userspace? Since this is a property of the interface
device, it'd seem natural to communicate the information in something
like a sysfs file for the device, or whatever's used to query properties
of network interfaces.
I'm a bit surprised the information isn't already there. Aren't
userspace applications eventually also supposed to be able to use rdma?
Don't they need to query network interfaces for their capabilities?
--b.
>
> Signed-off-by: Tom Tucker <tom@xxxxxxxxxxxxxxxxxxxxx>
>
> ---
> include/linux/sunrpc/svc_rdma.h | 1 +
> net/sunrpc/xprtrdma/svc_rdma.c | 8 ++++
> net/sunrpc/xprtrdma/svc_rdma_transport.c | 63 ++++++++++++++++++-----------
> 3 files changed, 48 insertions(+), 24 deletions(-)
>
> diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
> index c14fe86..7ee0a76 100644
> --- a/include/linux/sunrpc/svc_rdma.h
> +++ b/include/linux/sunrpc/svc_rdma.h
> @@ -52,6 +52,7 @@
> extern unsigned int svcrdma_ord;
> extern unsigned int svcrdma_max_requests;
> extern unsigned int svcrdma_max_req_size;
> +extern unsigned int svcrdma_show_conn_info;
>
> extern atomic_t rdma_stat_recv;
> extern atomic_t rdma_stat_read;
> diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
> index 8710117..493e243 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma.c
> @@ -58,6 +58,7 @@ static unsigned int max_max_requests = 16384;
> unsigned int svcrdma_max_req_size = RPCRDMA_MAX_REQ_SIZE;
> static unsigned int min_max_inline = 4096;
> static unsigned int max_max_inline = 65536;
> +unsigned int svcrdma_show_conn_info = 1;
>
> atomic_t rdma_stat_recv;
> atomic_t rdma_stat_read;
> @@ -145,6 +146,13 @@ static ctl_table svcrdma_parm_table[] = {
> .extra1 = &min_ord,
> .extra2 = &max_ord,
> },
> + {
> + .procname = "show_conn_info",
> + .data = &svcrdma_show_conn_info,
> + .maxlen = sizeof(svcrdma_show_conn_info),
> + .mode = 0644,
> + .proc_handler = &proc_dointvec,
> + },
>
> {
> .procname = "rdma_stat_read",
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
> index bd17023..3d97032 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
> @@ -833,6 +833,8 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
> struct rdma_conn_param conn_param;
> struct ib_qp_init_attr qp_attr;
> struct ib_device_attr devattr;
> + char *transport_string;
> + char *security_string;
> int dma_mr_acc;
> int need_dma_mr;
> int ret;
> @@ -981,10 +983,13 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
> /*
> * Determine if a DMA MR is required and if so, what privs are required
> */
> + security_string = "Safe. Only RPC memory exposed.";
> switch (rdma_node_get_transport(newxprt->sc_cm_id->device->node_type)) {
> case RDMA_TRANSPORT_IWARP:
> + transport_string = "iWARP";
> newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV;
> if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG)) {
> + security_string = "Unsafe: Server memory exposed.";
> need_dma_mr = 1;
> dma_mr_acc =
> (IB_ACCESS_LOCAL_WRITE |
> @@ -996,6 +1001,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
> need_dma_mr = 0;
> break;
> case RDMA_TRANSPORT_IB:
> + transport_string = "IB";
> if (!(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
> need_dma_mr = 1;
> dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
> @@ -1052,30 +1058,39 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
> goto errout;
> }
>
> - dprintk("svcrdma: new connection %p accepted with the following "
> - "attributes:\n"
> - " local_ip : %d.%d.%d.%d\n"
> - " local_port : %d\n"
> - " remote_ip : %d.%d.%d.%d\n"
> - " remote_port : %d\n"
> - " max_sge : %d\n"
> - " sq_depth : %d\n"
> - " max_requests : %d\n"
> - " ord : %d\n",
> - newxprt,
> - NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id->
> - route.addr.src_addr)->sin_addr.s_addr),
> - ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
> - route.addr.src_addr)->sin_port),
> - NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id->
> - route.addr.dst_addr)->sin_addr.s_addr),
> - ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
> - route.addr.dst_addr)->sin_port),
> - newxprt->sc_max_sge,
> - newxprt->sc_sq_depth,
> - newxprt->sc_max_requests,
> - newxprt->sc_ord);
> -
> + if (!svcrdma_show_conn_info)
> + goto out;
> +
> + printk(KERN_INFO "svcrdma: New connection accepted with the following "
> + "attributes:\n"
> + " transport : %s\n"
> + " local_ip : %d.%d.%d.%d\n"
> + " local_port : %d\n"
> + " remote_ip : %d.%d.%d.%d\n"
> + " remote_port : %d\n"
> + " max_sge : %d\n"
> + " sq_depth : %d\n"
> + " max_requests : %d\n"
> + " ord : %d\n"
> + " using fastreg? : %c\n"
> + " memory exposure : %s\n",
> + transport_string,
> + NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id->
> + route.addr.src_addr)->sin_addr.s_addr),
> + ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
> + route.addr.src_addr)->sin_port),
> + NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id->
> + route.addr.dst_addr)->sin_addr.s_addr),
> + ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
> + route.addr.dst_addr)->sin_port),
> + newxprt->sc_max_sge,
> + newxprt->sc_sq_depth,
> + newxprt->sc_max_requests,
> + newxprt->sc_ord,
> + newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG ? 'Y' : 'N',
> + security_string);
> +
> + out:
> return &newxprt->sc_xprt;
>
> errout:
--
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