mount: Allocate mountinfo strings dynamically

On the restore path this structure will be used and it
will be better to have them char * rather than char[64].

When scanning proc use the %ms specifier for this.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/proc_parse.h

@@ -89,14 +89,14 @@ struct proc_mountinfo {
 	int		mnt_id;
 	int		parent_mnt_id;
 	unsigned int	s_dev;
-	char		root[64];
-	char		mountpoint[64];
+	char		*root;
+	char		*mountpoint;
 	unsigned	flags;
 	int		master_id;
 	int		shared_id;
-	char		fstype[32];
-	char		source[64];
-	char		options[128];
+	char		*fstype;
+	char		*source;
+	char		*options;
 	struct proc_mountinfo *next;
 };
 

proc_parse.c

@@ -589,12 +589,12 @@ static int parse_mountinfo_ent(char *str, struct proc_mountinfo *new)
 {
 	unsigned int kmaj, kmin;
 	int ret, n;
-	char opt[64];
+	char *opt;
 
-	ret = sscanf(str, "%i %i %u:%u %63s %63s %63s %n",
+	ret = sscanf(str, "%i %i %u:%u %ms %ms %ms %n",
 			&new->mnt_id, &new->parent_mnt_id,
-			&kmaj, &kmin, new->root, new->mountpoint,
-			opt, &n);
+			&kmaj, &kmin, &new->root, &new->mountpoint,
+			&opt, &n);
 	if (ret != 7)
 		return -1;
 
@@ -603,18 +603,26 @@ static int parse_mountinfo_ent(char *str, struct proc_mountinfo *new)
 	if (parse_mnt_flags(opt, &new->flags))
 		return -1;
 
+	free(opt); /* after %ms scanf */
+
 	str += n;
 	if (parse_mnt_opt(str, new, &n))
 		return -1;
 
 	str += n;
-	ret = sscanf(str, "%31s %53s %63s", new->fstype, new->source, opt);
+	ret = sscanf(str, "%ms %ms %ms", &new->fstype, &new->source, &opt);
 	if (ret != 3)
 		return -1;
 
+	new->options = xmalloc(strlen(opt));
+	if (!new->options)
+		return -1;
+
 	if (parse_sb_opt(opt, &new->flags, new->options))
 		return -1;
 
+	free(opt);
+
 	return 0;
 }