fstyp: sync HAMMER1/2 detection support with DragonFly BSD.

Submitted by:	Tomohiro Kusumi
PR:		243929

usr.sbin/fstyp/hammer.c

@@ -1,5 +1,6 @@
 /*-
- * Copyright (c) 2016 The DragonFly Project
+ * Copyright (c) 2016-2019 The DragonFly Project
+ * Copyright (c) 2016-2019 Tomohiro Kusumi <[email protected]>
  * All rights reserved.
  *
  * This software was developed by Edward Tomasz Napierala under sponsorship
@@ -43,7 +44,7 @@ __FBSDID("$FreeBSD$");
 #include "fstyp.h"
 
 static hammer_volume_ondisk_t
-__read_ondisk(FILE *fp)
+read_ondisk(FILE *fp)
 {
 	hammer_volume_ondisk_t ondisk;
 
@@ -55,7 +56,7 @@ __read_ondisk(FILE *fp)
 }
 
 static int
-__test_ondisk(const hammer_volume_ondisk_t ondisk)
+test_ondisk(const hammer_volume_ondisk_t ondisk)
 {
 	static int count = 0;
 	static hammer_uuid_t fsid, fstype;
@@ -97,23 +98,23 @@ fstyp_hammer(FILE *fp, char *label, size_t size)
 	hammer_volume_ondisk_t ondisk;
 	int error = 1;
 
-	ondisk = __read_ondisk(fp);
+	ondisk = read_ondisk(fp);
 	if (ondisk->vol_no != HAMMER_ROOT_VOLNO)
-		goto done;
+		goto fail;
 	if (ondisk->vol_count != 1)
-		goto done;
-	if (__test_ondisk(ondisk))
-		goto done;
+		goto fail;
+	if (test_ondisk(ondisk))
+		goto fail;
 
 	strlcpy(label, ondisk->vol_label, size);
 	error = 0;
-done:
+fail:
 	free(ondisk);
 	return (error);
 }
 
 static int
-__test_volume(const char *volpath)
+test_volume(const char *volpath)
 {
 	hammer_volume_ondisk_t ondisk;
 	FILE *fp;
@@ -122,65 +123,74 @@ __test_volume(const char *volpath)
 	if ((fp = fopen(volpath, "r")) == NULL)
 		err(1, "failed to open %s", volpath);
 
-	ondisk = __read_ondisk(fp);
+	ondisk = read_ondisk(fp);
 	fclose(fp);
-	if (__test_ondisk(ondisk))
-		goto done;
+	if (test_ondisk(ondisk))
+		goto fail;
 
 	volno = ondisk->vol_no;
-done:
+fail:
 	free(ondisk);
 	return (volno);
 }
 
 static int
 __fsvtyp_hammer(const char *blkdevs, char *label, size_t size, int partial)
 {
-	hammer_volume_ondisk_t ondisk;
+	hammer_volume_ondisk_t ondisk = NULL;
 	FILE *fp;
 	char *dup, *p, *volpath, x[HAMMER_MAX_VOLUMES];
 	int i, volno, error = 1;
 
+	if (!blkdevs)
+		goto fail;
+
 	memset(x, 0, sizeof(x));
 	dup = strdup(blkdevs);
 	p = dup;
 
+	volpath = NULL;
+	volno = -1;
 	while (p) {
 		volpath = p;
 		if ((p = strchr(p, ':')) != NULL)
 			*p++ = '\0';
-		if ((volno = __test_volume(volpath)) == -1)
+		if ((volno = test_volume(volpath)) == -1)
 			break;
+		assert(volno >= 0);
+		assert(volno < HAMMER_MAX_VOLUMES);
 		x[volno]++;
 	}
 
+	if (!volpath)
+		err(1, "invalid path %s", blkdevs);
 	if ((fp = fopen(volpath, "r")) == NULL)
 		err(1, "failed to open %s", volpath);
-	ondisk = __read_ondisk(fp);
+	ondisk = read_ondisk(fp);
 	fclose(fp);
 
 	free(dup);
 
 	if (volno == -1)
-		goto done;
+		goto fail;
 	if (partial)
 		goto success;
 
 	for (i = 0; i < HAMMER_MAX_VOLUMES; i++)
 		if (x[i] > 1)
-			goto done;
+			goto fail;
 	for (i = 0; i < HAMMER_MAX_VOLUMES; i++)
 		if (x[i] == 0)
 			break;
 	if (ondisk->vol_count != i)
-		goto done;
+		goto fail;
 	for (; i < HAMMER_MAX_VOLUMES; i++)
 		if (x[i] != 0)
-			goto done;
+			goto fail;
 success:
 	strlcpy(label, ondisk->vol_label, size);
 	error = 0;
-done:
+fail:
 	free(ondisk);
 	return (error);
 }