In check.c:

Avoid shadowing declarations.
Avoid compairing signed and unsigned types.

sbin/fsck_msdosfs/check.c

@@ -49,8 +49,7 @@ static const char rcsid[] =
 #include "fsutil.h"
 
 int
-checkfilesys(fname)
-	const char *fname;
+checkfilesys(const char *fname)
 {
 	int dosfs;
 	struct bootblock boot;
@@ -99,7 +98,7 @@ checkfilesys(fname)
 	}
 
 	if (boot.ValidFat < 0)
-		for (i = 1; i < boot.FATs; i++) {
+		for (i = 1; i < (int)boot.FATs; i++) {
 			struct fatEntry *currentFat;
 
 			mod |= readfat(dosfs, &boot, i, &currentFat);

sbin/fsck_msdosfs/ext.h

@@ -49,8 +49,6 @@ extern int alwaysyes;	/* assume "yes" for all questions */
 extern int preen;	/* we are preening */
 extern int rdonly;	/* device is opened read only (supersedes above) */
 
-extern char *fname;	/* file system currently checked */
-
 extern struct dosDirEntry *rootDir;
 
 /*