Fix problem with geom_label(4) not recognizing UFS labels on filesystems

extended using growfs(8).  The problem here is that geom_label checks if
the filesystem size recorded in UFS superblock is equal to the provider
(i.e. device) size.  This check cannot be removed due to backward
compatibility.  On the other hand, in most cases growfs(8) cannot set
fs_size in the superblock to match the provider size, because, differently
from newfs(8), it cannot recompute cylinder group sizes.

To fix this problem, add another superblock field, fs_providersize, used
only for this purpose.  The geom_label(4) will attach if either fs_size
(filesystem created with newfs(8)) or fs_providersize (filesystem expanded
using growfs(8)) matches the device size.

PR:		kern/165962
Reviewed by:	mckusick
Sponsored by:	FreeBSD Foundation

sbin/dumpfs/dumpfs.c

@@ -277,8 +277,9 @@ dumpfs(const char *name)
 		printf("unknown flags (%#x)", fsflags);
 	putchar('\n');
 	printf("fsmnt\t%s\n", afs.fs_fsmnt);
-	printf("volname\t%s\tswuid\t%ju\n",
-		afs.fs_volname, (uintmax_t)afs.fs_swuid);
+	printf("volname\t%s\tswuid\t%ju\tprovidersize\t%ju\n",
+		afs.fs_volname, (uintmax_t)afs.fs_swuid,
+		(uintmax_t)afs.fs_providersize);
 	printf("\ncs[].cs_(nbfree,ndir,nifree,nffree):\n\t");
 	afs.fs_csp = calloc(1, afs.fs_cssize);
 	if (bread(&disk, fsbtodb(&afs, afs.fs_csaddr), afs.fs_csp, afs.fs_cssize) == -1)

sbin/growfs/growfs.c

@@ -1498,6 +1498,7 @@ main(int argc, char **argv)
 	}
 
 	sblock.fs_size = dbtofsb(&osblock, size / DEV_BSIZE);
+	sblock.fs_providersize = dbtofsb(&osblock, mediasize / DEV_BSIZE);
 
 	/*
 	 * Are we really growing?

sbin/newfs/mkfs.c

@@ -263,6 +263,7 @@ restart:
 	}
 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
+	sblock.fs_providersize = dbtofsb(&sblock, mediasize / sectorsize);
 
 	/*
 	 * Before the filesystem is finally initialized, mark it

sbin/newfs/newfs.c

@@ -94,6 +94,7 @@ int	lflag;			/* enable multilabel for file system */
 int	nflag;			/* do not create .snap directory */
 int	tflag;			/* enable TRIM */
 intmax_t fssize;		/* file system size */
+off_t	mediasize;		/* device size */
 int	sectorsize;		/* bytes/sector */
 int	realsectorsize;		/* bytes/sector in hardware */
 int	fsize = 0;		/* fragment size */
@@ -135,7 +136,6 @@ main(int argc, char *argv[])
 	char *cp, *special;
 	intmax_t reserved;
 	int ch, i, rval;
-	off_t mediasize;
 	char part_name;		/* partition name, default to full disk */
 
 	part_name = 'c';

sbin/newfs/newfs.h

@@ -88,6 +88,7 @@ extern int	lflag;		/* enable multilabel MAC for file system */
 extern int	nflag;		/* do not create .snap directory */
 extern int	tflag;		/* enable TRIM */
 extern intmax_t	fssize;		/* file system size */
+extern off_t	mediasize;	/* device size */
 extern int	sectorsize;	/* bytes/sector */
 extern int	realsectorsize;	/* bytes/sector in hardware*/
 extern int	fsize;		/* fragment size */

sys/geom/label/g_label_ufs.c

@@ -90,7 +90,8 @@ g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int wh
 		    pp->mediasize / fs->fs_fsize == fs->fs_old_size) {
 		    	/* Valid UFS1. */
 		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
-		    pp->mediasize / fs->fs_fsize == fs->fs_size) {
+		    ((pp->mediasize / fs->fs_fsize == fs->fs_size) ||
+		    (pp->mediasize / fs->fs_fsize == fs->fs_providersize))) {
 		    	/* Valid UFS2. */
 		} else {
 			g_free(fs);

sys/ufs/ffs/fs.h

@@ -329,7 +329,8 @@ struct fs {
 	int32_t	 fs_old_cpc;		/* cyl per cycle in postbl */
 	int32_t	 fs_maxbsize;		/* maximum blocking factor permitted */
 	int64_t	 fs_unrefs;		/* number of unreferenced inodes */
-	int64_t	 fs_sparecon64[16];	/* old rotation block list head */
+	int64_t  fs_providersize;	/* size of underlying GEOM provider */
+	int64_t	 fs_sparecon64[15];	/* old rotation block list head */
 	int64_t	 fs_sblockloc;		/* byte offset of standard superblock */
 	struct	csum_total fs_cstotal;	/* (u) cylinder summary information */
 	ufs_time_t fs_time;		/* last time written */