ext4: Use printf extension %pV

Using %pV reduces the number of printk calls and eliminates any
possible message interleaving from other printk calls.

In function __ext4_grp_locked_error also added KERN_CONT to some
printks.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/super.c

@@ -388,13 +388,14 @@ static void ext4_handle_error(struct super_block *sb)
 void __ext4_error(struct super_block *sb, const char *function,
 		  unsigned int line, const char *fmt, ...)
 {
+	struct va_format vaf;
 	va_list args;
 
 	va_start(args, fmt);
-	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: ",
-	       sb->s_id, function, line, current->comm);
-	vprintk(fmt, args);
-	printk("\n");
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
+	       sb->s_id, function, line, current->comm, &vaf);
 	va_end(args);
 
 	ext4_handle_error(sb);
@@ -543,28 +544,29 @@ void __ext4_abort(struct super_block *sb, const char *function,
 		panic("EXT4-fs panic from previous error\n");
 }
 
-void ext4_msg (struct super_block * sb, const char *prefix,
-		   const char *fmt, ...)
+void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 {
+	struct va_format vaf;
 	va_list args;
 
 	va_start(args, fmt);
-	printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
-	vprintk(fmt, args);
-	printk("\n");
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 	va_end(args);
 }
 
 void __ext4_warning(struct super_block *sb, const char *function,
 		    unsigned int line, const char *fmt, ...)
 {
+	struct va_format vaf;
 	va_list args;
 
 	va_start(args, fmt);
-	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: ",
-	       sb->s_id, function, line);
-	vprintk(fmt, args);
-	printk("\n");
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
+	       sb->s_id, function, line, &vaf);
 	va_end(args);
 }
 
@@ -575,21 +577,25 @@ void __ext4_grp_locked_error(const char *function, unsigned int line,
 __releases(bitlock)
 __acquires(bitlock)
 {
+	struct va_format vaf;
 	va_list args;
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 
 	es->s_last_error_ino = cpu_to_le32(ino);
 	es->s_last_error_block = cpu_to_le64(block);
 	__save_error_info(sb, function, line);
+
 	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u",
 	       sb->s_id, function, line, grp);
 	if (ino)
-		printk("inode %lu: ", ino);
+		printk(KERN_CONT "inode %lu: ", ino);
 	if (block)
-		printk("block %llu:", (unsigned long long) block);
-	vprintk(fmt, args);
-	printk("\n");
+		printk(KERN_CONT "block %llu:", (unsigned long long) block);
+	printk(KERN_CONT "%pV\n", &vaf);
 	va_end(args);
 
 	if (test_opt(sb, ERRORS_CONT)) {