SUNRPC: pass buffer size to svc_sock_names()

Adjust the synopsis of svc_sock_names() to pass in the size of the
output buffer.  Add a documenting comment.

This is a cosmetic change for now.  A subsequent patch will make sure
the buffer length is passed to one_sock_name(), where the length will
actually be useful.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

3 files changed, 22 insertions, 4 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 1f1c2159b802..b64a7fbfccf5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -966,7 +966,8 @@ static ssize_t __write_ports_delfd(char *buf)
                 return -ENOMEM;
 
         if (nfsd_serv != NULL)
-                len = svc_sock_names(buf, nfsd_serv, toclose);
+                len = svc_sock_names(nfsd_serv, buf,
+                                        SIMPLE_TRANSACTION_LIMIT, toclose);
         if (len >= 0)
                 lockd_down();
 
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index e23241c53f42..827163138949 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -38,7 +38,9 @@ int		svc_recv(struct svc_rqst *, long);
 int             svc_send(struct svc_rqst *);
 void            svc_drop(struct svc_rqst *);
 void            svc_sock_update_bufs(struct svc_serv *serv);
-int             svc_sock_names(char *buf, struct svc_serv *serv, char *toclose);
+int             svc_sock_names(struct svc_serv *serv, char *buf,
+                                        const size_t buflen,
+                                        const char *toclose);
 int             svc_addsock(struct svc_serv *serv, const int fd,
                                         char *name_return, const size_t len);
 void            svc_init_xprt_sock(void);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 6bec1e25b542..032b52ea9541 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -259,8 +259,23 @@ static int one_sock_name(char *buf, struct svc_sock *svsk)
         return len;
 }
 
-int
-svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
+/**
+ * svc_sock_names - construct a list of listener names in a string
+ * @serv: pointer to RPC service
+ * @buf: pointer to a buffer to fill in with socket names
+ * @buflen: size of the buffer to be filled
+ * @toclose: pointer to '\0'-terminated C string containing the name
+ *              of a listener to be closed
+ *
+ * Fills in @buf with a '\n'-separated list of names of listener
+ * sockets.  If @toclose is not NULL, the socket named by @toclose
+ * is closed, and is not included in the output list.
+ *
+ * Returns positive length of the socket name string, or a negative
+ * errno value on error.
+ */
+int svc_sock_names(struct svc_serv *serv, char *buf, const size_t buflen,
+                   const char *toclose)
 {
         struct svc_sock *svsk, *closesk = NULL;
         int len = 0;