Ensure that newfs will never create a filesystem with more than 2^32

inodes by cutting back on the number of inodes per cylinder group if
necessary to stay under the limit. For a default (16K block) file
system, this limit begins to take effect for file systems above 32Tb.

This fix is in addition to -r203763 which corrected a problem in the
kernel that treated large inode numbers as negative rather than unsigned.
For a default (16K block) file system, this bug began to show up at a
file system size above about 16Tb.

Reported by: Scott Burns, John Kilburg, Bruce Evans
Followup by: Jeff Roberson
PR:          133980
MFC after:   2 weeks

1 files changed, 32 insertions, 0 deletions

diff --git a/sbin/newfs/newfs.h b/sbin/newfs/newfs.h
index 0d7cb62..9da3226 100644
--- a/sbin/newfs/newfs.h
+++ b/sbin/newfs/newfs.h
@@ -41,6 +41,38 @@
 #include <libufs.h>
 
 /*
+ * The following two constants set the default block and fragment sizes.
+ * Both constants must be a power of 2 and meet the following constraints:
+ *	MINBSIZE <= DESBLKSIZE <= MAXBSIZE
+ *	sectorsize <= DESFRAGSIZE <= DESBLKSIZE
+ *	DESBLKSIZE / DESFRAGSIZE <= 8
+ */
+#define	DFL_FRAGSIZE	2048
+#define	DFL_BLKSIZE	16384
+
+/*
+ * Cylinder groups may have up to MAXBLKSPERCG blocks. The actual
+ * number used depends upon how much information can be stored
+ * in a cylinder group map which must fit in a single file system
+ * block. The default is to use as many as possible blocks per group.
+ */
+#define	MAXBLKSPERCG	0x7fffffff	/* desired fs_fpg ("infinity") */
+
+/*
+ * MAXBLKPG determines the maximum number of data blocks which are
+ * placed in a single cylinder group. The default is one indirect
+ * block worth of data blocks.
+ */
+#define MAXBLKPG(bsize)	((bsize) / sizeof(ufs2_daddr_t))
+
+/*
+ * Each file system has a number of inodes statically allocated.
+ * We allocate one inode slot per NFPI fragments, expecting this
+ * to be far more than we will ever need.
+ */
+#define	NFPI		4
+
+/*
  * variables set up by front end.
  */
 extern int	Eflag;		/* Erase previous disk contents */