Allocate extra inodes in makefs when leaving free space in UFS images.

By default, makefs(8) has very few spare inodes in its output images,
which is fine for static filesystems, but not so great for VM images
where many more files will be added. Make makefs(8) use the same
default settings as newfs(8) when creating images with free space --
there isn't much point to leaving free space on the image if you
can't put files there. If no free space is requested, use current
behavior of a minimal number of available inodes.

Reviewed by:	manu
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D29492

usr.sbin/makefs/ffs.c

@@ -190,6 +190,7 @@ ffs_prep_opts(fsinfo_t *fsopts)
 	ffs_opts->fsize= -1;
 	ffs_opts->cpg= -1;
 	ffs_opts->density= -1;
+	ffs_opts->min_inodes= false;
 	ffs_opts->minfree= -1;
 	ffs_opts->optimization= -1;
 	ffs_opts->maxcontig= -1;
@@ -266,6 +267,11 @@ ffs_makefs(const char *image, const char *dir, fsnode *root, fsinfo_t *fsopts)
 		printf("ffs_makefs: image %s directory %s root %p\n",
 		    image, dir, root);
 
+		/* if user wants no free space, use minimum number of inodes */
+	if (fsopts->minsize == 0 && fsopts->freeblockpc == 0 &&
+	    fsopts->freeblocks == 0)
+		((ffs_opt_t *)fsopts->fs_specific)->min_inodes = true;
+
 		/* validate tree and options */
 	TIMER_START(start);
 	ffs_validate(dir, root, fsopts);
@@ -424,7 +430,7 @@ ffs_validate(const char *dir, fsnode *root, fsinfo_t *fsopts)
 	if (fsopts->roundup > 0)
 		fsopts->size = roundup(fsopts->size, fsopts->roundup);
 
-		/* calculate density if necessary */
+		/* calculate density to just fit inodes if no free space */
 	if (ffs_opts->density == -1)
 		ffs_opts->density = fsopts->size / fsopts->inodes + 1;
 

usr.sbin/makefs/ffs.h

@@ -44,6 +44,7 @@
 
 #include <ufs/ufs/dinode.h>
 #include <ufs/ffs/fs.h>
+#include <stdbool.h>
 
 typedef struct {
 	char	label[MAXVOLLEN];	/* volume name/label */
@@ -52,6 +53,7 @@ typedef struct {
 	int	cpg;		/* cylinders per group */
 	int	cpgflg;		/* cpg was specified by user */
 	int	density;	/* bytes per inode */
+	bool	min_inodes;	/* allocate minimum number of inodes */
 	int	ntracks;	/* number of tracks */
 	int	nsectors;	/* number of sectors */
 	int	rpm;		/* rpm */

usr.sbin/makefs/ffs/mkfs.c

@@ -117,10 +117,13 @@ static int     avgfpdir;	   /* expected number of files per directory */
 struct fs *
 ffs_mkfs(const char *fsys, const fsinfo_t *fsopts, time_t tstamp)
 {
-	int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
+	int fragsperinode, optimalfpg, origdensity, mindensity;
+	int minfpg, lastminfpg;
 	int32_t csfrags;
 	uint32_t i, cylno;
 	long long sizepb;
+	ino_t maxinum;
+	int minfragsperinode;   /* minimum ratio of frags to inodes */
 	void *space;
 	int size;
 	int nprintcols, printcolwidth;
@@ -312,7 +315,20 @@ ffs_mkfs(const char *fsys, const fsinfo_t *fsopts, time_t tstamp)
 	 * can put into each cylinder group. If this is too big, we reduce
 	 * the density until it fits.
 	 */
+	maxinum = (((int64_t)(1)) << 32) - INOPB(&sblock);
+	minfragsperinode = 1 + fssize / maxinum;
+	mindensity = minfragsperinode * fsize;
+	if (density == 0)
+		density = MAX(2, minfragsperinode) * fsize;
+	if (density < mindensity) {
+		origdensity = density;
+		density = mindensity;
+		fprintf(stderr, "density increased from %d to %d\n",
+		    origdensity, density);
+	}
 	origdensity = density;
+	if (!ffs_opts->min_inodes)
+		density = MIN(density, MAX(2, minfragsperinode) * fsize);
 	for (;;) {
 		fragsperinode = MAX(numfrags(&sblock, density), 1);
 		minfpg = fragsperinode * INOPB(&sblock);

usr.sbin/makefs/makefs.8

@@ -312,7 +312,10 @@ Expected number of files per directory.
 .It Sy bsize
 Block size.
 .It Sy density
-Bytes per inode.
+Bytes per inode. If unset, will allocate the minimum number of inodes to
+represent the filesystem if no free space has been requested (free blocks
+or minimum size set); otherwise the larger of the newfs defaults or what
+is required by the free inode parameters if set.
 .It Sy fsize
 Fragment size.
 .It Sy label