Initial revision

lib/other/fsversion.c

@@ -0,0 +1,52 @@
+/* This procedure examines a file system and figures out whether it is
+ * version 1 or version 2.  It returns the result as an int.  If the
+ * file system is neither, it returns -1.  A typical call is:
+ *
+ *	n = fsversion("/dev/hd1", "df");
+ *
+ * The first argument is the special file for the file system. 
+ * The second is the program name, which is used in error messages.
+ */
+
+#include <sys/types.h>
+#include <minix/config.h>
+#include <minix/const.h>
+#include <minix/minlib.h>
+#include <minix/type.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "fs/const.h"
+#include "fs/type.h"
+#include "fs/super.h"
+
+static struct super_block super, *sp;
+
+int fsversion(dev, prog)
+char *dev, *prog;
+{
+  int fd;
+
+  if ((fd = open(dev, O_RDONLY)) < 0) {
+	std_err(prog);
+	std_err(" cannot open ");
+	perror(dev);
+	return(-1);
+  }
+
+  lseek(fd, (off_t) SUPER_BLOCK_BYTES, SEEK_SET);	/* skip boot block */
+  if (read(fd, (char *) &super, (unsigned) SUPER_SIZE) != SUPER_SIZE) {
+	std_err(prog);
+	std_err(" cannot read super block on ");
+	perror(dev);
+	close(fd);
+	return(-1);
+  }
+  close(fd);
+  sp = &super;
+  if (sp->s_magic == SUPER_MAGIC) return(1);
+  if (sp->s_magic == SUPER_V2) return(2);
+  if (sp->s_magic == SUPER_V3) return(3);
+  return(-1);
+}