fsck.f2fs: support -p without argument

This patch allows fsck run -p without argument. So we could use -p as
-p, -p 0, -p 1. '-p' and '-p 0' have the same meaning as '-a'. '-p 1'
check more meta data than '-a'.

Reported-by: KARBOWSKI Piotr <piotr.karbowski@gmail.com>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fsck/main.c b/fsck/main.c
index 39ef8d3..0ac1711 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -17,6 +17,7 @@
  */
 #include "fsck.h"
 #include <libgen.h>
+#include <ctype.h>
 
 struct f2fs_fsck gfsck;
 
@@ -77,13 +78,54 @@
 	exit(1);
 }
 
+static void __handle_fsck_args(int optopt)
+{
+	switch (optopt) {
+	case 'p':
+		MSG(0, "Info: Use default preen mode\n");
+		c.preen_mode = PREEN_MODE_0;
+		c.auto_fix = 1;
+		break;
+	default:
+		MSG(0, "\tError: Need argument for -%c\n", optopt);
+		fsck_usage();
+	}
+}
+
+static int is_digits(char *optarg)
+{
+	int i;
+
+	for (i = 0; i < strlen(optarg); i++)
+		if (!isdigit(optarg[i]))
+			break;
+	return i == strlen(optarg);
+}
+
 void f2fs_parse_options(int argc, char *argv[])
 {
 	int option = 0;
 	char *prog = basename(argv[0]);
+	int err = 0;
+
+	if (argc < 2) {
+		MSG(0, "\tError: Device not specified\n");
+		if (c.func == FSCK)
+			fsck_usage();
+		else if (c.func == DUMP)
+			dump_usage();
+		else if (c.func == DEFRAG)
+			defrag_usage();
+		else if (c.func == RESIZE)
+			resize_usage();
+		else if (c.func == SLOAD)
+			sload_usage();
+	}
+	c.devices[0].path = strdup(argv[argc - 1]);
+	argv[argc-- - 1] = 0;
 
 	if (!strcmp("fsck.f2fs", prog)) {
-		const char *option_string = "ad:fp:t";
+		const char *option_string = ":ad:fp:t";
 
 		c.func = FSCK;
 		while ((option = getopt(argc, argv, option_string)) != EOF) {
@@ -97,6 +139,16 @@
 				 *  0: default level, the same as -a
 				 *  1: check meta
 				 */
+				if (optarg[0] == '-') {
+					c.preen_mode = PREEN_MODE_0;
+					optind--;
+					break;
+				} else if (!is_digits(optarg)) {
+					MSG(0, "\tError: Wrong option -%c %s\n",
+							option, optarg);
+					err = 1;
+					break;
+				}
 				c.preen_mode = atoi(optarg);
 				if (c.preen_mode < 0)
 					c.preen_mode = PREEN_MODE_0;
@@ -108,9 +160,19 @@
 					"preen mode %d\n", c.preen_mode);
 				break;
 			case 'd':
+				if (optarg[0] == '-') {
+					MSG(0, "\tError: Need argument for -%c\n",
+							option);
+					err = 1;
+					break;
+				} else if (!is_digits(optarg)) {
+					MSG(0, "\tError: Wrong option -%c %s\n",
+							option, optarg);
+					err = 1;
+					break;
+				}
 				c.dbg_lv = atoi(optarg);
-				MSG(0, "Info: Debug level = %d\n",
-							c.dbg_lv);
+				MSG(0, "Info: Debug level = %d\n", c.dbg_lv);
 				break;
 			case 'f':
 				c.fix_on = 1;
@@ -119,11 +181,25 @@
 			case 't':
 				c.dbg_lv = -1;
 				break;
+			case ':':
+				__handle_fsck_args(optopt);
+				break;
+			case '?':
+				MSG(0, "\tError: Unknown option %c\n", optopt);
+				err = 1;
+				break;
 			default:
 				MSG(0, "\tError: Unknown option %c\n", option);
-				fsck_usage();
+				err = 1;
 				break;
 			}
+			if (err)
+				fsck_usage();
+		}
+		if (argc > optind) {
+			c.dbg_lv = 0;
+			MSG(0, "\tError: Unknown argument %s\n", argv[optind]);
+			fsck_usage();
 		}
 	} else if (!strcmp("dump.f2fs", prog)) {
 		const char *option_string = "d:i:n:s:a:b:";
@@ -287,21 +363,6 @@
 			}
 		}
 	}
-
-	if ((optind + 1) != argc) {
-		MSG(0, "\tError: Device not specified\n");
-		if (c.func == FSCK)
-			fsck_usage();
-		else if (c.func == DUMP)
-			dump_usage();
-		else if (c.func == DEFRAG)
-			defrag_usage();
-		else if (c.func == RESIZE)
-			resize_usage();
-		else if (c.func == SLOAD)
-			sload_usage();
-	}
-	c.devices[0].path = strdup(argv[optind]);
 }
 
 static void do_fsck(struct f2fs_sb_info *sbi)