sunrpc & nfs: Add and use dprintk_cont macros

Allow line continuations to work properly with KERN_CONT.
Signed-off-by: Joe Perches <joe@perches.com>
[Anna: Add fallback dprintk_cont() for when CONFIG_SUNRPC_DEBUG=n]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/write.c

@@ -1787,7 +1787,7 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
 		if (status < 0) {
 			nfs_context_set_write_error(req->wb_context, status);
 			nfs_inode_remove_request(req);
-			dprintk(", error = %d\n", status);
+			dprintk_cont(", error = %d\n", status);
 			goto next;
 		}
 
@@ -1796,11 +1796,11 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
 		if (!nfs_write_verifier_cmp(&req->wb_verf, &data->verf.verifier)) {
 			/* We have a match */
 			nfs_inode_remove_request(req);
-			dprintk(" OK\n");
+			dprintk_cont(" OK\n");
 			goto next;
 		}
 		/* We have a mismatch. Write the page again */
-		dprintk(" mismatch\n");
+		dprintk_cont(" mismatch\n");
 		nfs_mark_request_dirty(req);
 		set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
 	next:

include/linux/sunrpc/debug.h

@@ -20,33 +20,55 @@ extern unsigned int		nfsd_debug;
 extern unsigned int		nlm_debug;
 #endif
 
-#define dprintk(args...)	dfprintk(FACILITY, ## args)
-#define dprintk_rcu(args...)	dfprintk_rcu(FACILITY, ## args)
+#define dprintk(fmt, ...)						\
+	dfprintk(FACILITY, fmt, ##__VA_ARGS__)
+#define dprintk_cont(fmt, ...)						\
+	dfprintk_cont(FACILITY, fmt, ##__VA_ARGS__)
+#define dprintk_rcu(fmt, ...)						\
+	dfprintk_rcu(FACILITY, fmt, ##__VA_ARGS__)
+#define dprintk_rcu_cont(fmt, ...)					\
+	dfprintk_rcu_cont(FACILITY, fmt, ##__VA_ARGS__)
 
 #undef ifdebug
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define ifdebug(fac)		if (unlikely(rpc_debug & RPCDBG_##fac))
 
-# define dfprintk(fac, args...)	\
-	do { \
+# define dfprintk(fac, fmt, ...)					\
+do {									\
 	ifdebug(fac)							\
-			printk(KERN_DEFAULT args); \
-	} while (0)
+		printk(KERN_DEFAULT fmt, ##__VA_ARGS__);		\
+} while (0)
 
-# define dfprintk_rcu(fac, args...)	\
-	do { \
+# define dfprintk_cont(fac, fmt, ...)					\
+do {									\
+	ifdebug(fac)							\
+		printk(KERN_CONT fmt, ##__VA_ARGS__);			\
+} while (0)
+
+# define dfprintk_rcu(fac, fmt, ...)					\
+do {									\
+	ifdebug(fac) {							\
+		rcu_read_lock();					\
+		printk(KERN_DEFAULT fmt, ##__VA_ARGS__);		\
+		rcu_read_unlock();					\
+	}								\
+} while (0)
+
+# define dfprintk_rcu_cont(fac, fmt, ...)				\
+do {									\
 	ifdebug(fac) {							\
 		rcu_read_lock();					\
-			printk(KERN_DEFAULT args); \
+		printk(KERN_CONT fmt, ##__VA_ARGS__);			\
 		rcu_read_unlock();					\
 	}								\
-	} while (0)
+} while (0)
 
 # define RPC_IFDEBUG(x)		x
 #else
 # define ifdebug(fac)		if (0)
-# define dfprintk(fac, args...)	do {} while (0)
-# define dfprintk_rcu(fac, args...)	do {} while (0)
+# define dfprintk(fac, fmt, ...)	do {} while (0)
+# define dfprintk_cont(fac, fmt, ...)	do {} while (0)
+# define dfprintk_rcu(fac, fmt, ...)	do {} while (0)
 # define RPC_IFDEBUG(x)
 #endif