svc: Add /proc/sys/sunrpc/transport files

Add a file that when read lists the set of registered svc
transports.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 405281e..01e71b7 100644 (file)
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -79,6 +79,7 @@ void  svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt);
 void   svc_close_xprt(struct svc_xprt *xprt);
 void   svc_delete_xprt(struct svc_xprt *xprt);
 int    svc_port_is_privileged(struct sockaddr *sin);
+int    svc_print_xprts(char *buf, int maxlen);
 
 static inline void svc_xprt_get(struct svc_xprt *xprt)
 {

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 000c7dc..2e5b92a 100644 (file)
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -112,6 +112,34 @@ void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
 }
 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
 
+/*
+ * Format the transport list for printing
+ */
+int svc_print_xprts(char *buf, int maxlen)
+{
+       struct list_head *le;
+       char tmpstr[80];
+       int len = 0;
+       buf[0] = '\0';
+
+       spin_lock(&svc_xprt_class_lock);
+       list_for_each(le, &svc_xprt_class_list) {
+               int slen;
+               struct svc_xprt_class *xcl =
+                       list_entry(le, struct svc_xprt_class, xcl_list);
+
+               sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
+               slen = strlen(tmpstr);
+               if (len + slen > maxlen)
+                       break;
+               len += slen;
+               strcat(buf, tmpstr);
+       }
+       spin_unlock(&svc_xprt_class_lock);
+
+       return len;
+}
+
 static void svc_xprt_free(struct kref *kref)
 {
        struct svc_xprt *xprt =

diff --git a/net/sunrpc/sysctl.c b/net/sunrpc/sysctl.c
index bada7de..0f8c439 100644 (file)
--- a/net/sunrpc/sysctl.c
+++ b/net/sunrpc/sysctl.c
@@ -18,6 +18,7 @@
 #include <linux/sunrpc/types.h>
 #include <linux/sunrpc/sched.h>
 #include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/svc_xprt.h>
 
 /*
  * Declare the debug flags here
@@ -55,6 +56,30 @@ rpc_unregister_sysctl(void)
        }
 }
 
+static int proc_do_xprt(ctl_table *table, int write, struct file *file,
+                       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+       char tmpbuf[256];
+       int len;
+       if ((*ppos && !write) || !*lenp) {
+               *lenp = 0;
+               return 0;
+       }
+       if (write)
+               return -EINVAL;
+       else {
+               len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
+               if (!access_ok(VERIFY_WRITE, buffer, len))
+                       return -EFAULT;
+
+               if (__copy_to_user(buffer, tmpbuf, len))
+                       return -EFAULT;
+       }
+       *lenp -= len;
+       *ppos += len;
+       return 0;
+}
+
 static int
 proc_dodebug(ctl_table *table, int write, struct file *file,
                                void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -147,6 +172,12 @@ static ctl_table debug_table[] = {
                .mode           = 0644,
                .proc_handler   = &proc_dodebug
        },
+       {
+               .procname       = "transports",
+               .maxlen         = 256,
+               .mode           = 0444,
+               .proc_handler   = &proc_do_xprt,
+       },
        { .ctl_name = 0 }
 };