diff --git a/lib/libufs/libufs.h b/lib/libufs/libufs.h
index dbd378949877..9d1e7355c2f7 100644
--- a/lib/libufs/libufs.h
+++ b/lib/libufs/libufs.h
@@ -117,6 +117,12 @@ int	ffs_sbget(void *, struct fs **, off_t, char *,
 int	ffs_sbput(void *, struct fs *, off_t,
 	    int (*)(void *, off_t, void *, int));
 
+/*
+ * Request standard superblock location in ffs_sbget
+ */
+#define	STDSB			-1	/* Fail if check-hash is bad */
+#define	STDSB_NOHASHFAIL	-2	/* Ignore check-hash failure */
+
 /*
  * block.c
  */
diff --git a/lib/libufs/sblock.c b/lib/libufs/sblock.c
index 29ff258b6ebf..53c8d44f6d65 100644
--- a/lib/libufs/sblock.c
+++ b/lib/libufs/sblock.c
@@ -54,7 +54,7 @@ sbread(struct uufsd *disk)
 
 	ERROR(disk, NULL);
 
-	if ((errno = sbget(disk->d_fd, &fs, -1)) != 0) {
+	if ((errno = sbget(disk->d_fd, &fs, STDSB)) != 0) {
 		switch (errno) {
 		case EIO:
 			ERROR(disk, "non-existent or truncated superblock");
diff --git a/sbin/dump/main.c b/sbin/dump/main.c
index 7301ca318d80..135b4fcfb64c 100644
--- a/sbin/dump/main.c
+++ b/sbin/dump/main.c
@@ -433,7 +433,7 @@ main(int argc, char *argv[])
 		msgtail("to %s\n", tape);
 
 	sync();
-	if ((ret = sbget(diskfd, &sblock, -1)) != 0) {
+	if ((ret = sbget(diskfd, &sblock, STDSB)) != 0) {
 		switch (ret) {
 		case ENOENT:
 			warn("Cannot find file system superblock");
diff --git a/sbin/fsck_ffs/setup.c b/sbin/fsck_ffs/setup.c
index 82a970e12858..8599f6cde739 100644
--- a/sbin/fsck_ffs/setup.c
+++ b/sbin/fsck_ffs/setup.c
@@ -327,7 +327,7 @@ readsb(int listerr)
 	int bad, ret;
 	struct fs *fs;
 
-	super = bflag ? bflag * dev_bsize : -1;
+	super = bflag ? bflag * dev_bsize : STDSB;
 	readcnt[sblk.b_type]++;
 	if ((ret = sbget(fsreadfd, &fs, super)) != 0) {
 		switch (ret) {
diff --git a/sbin/fsirand/fsirand.c b/sbin/fsirand/fsirand.c
index f5e26571f903..8675f7c3fd33 100644
--- a/sbin/fsirand/fsirand.c
+++ b/sbin/fsirand/fsirand.c
@@ -126,7 +126,7 @@ fsirand(char *device)
 	dp2 = NULL;
 
 	/* Read in master superblock */
-	if ((ret = sbget(devfd, &sblock, -1)) != 0) {
+	if ((ret = sbget(devfd, &sblock, STDSB)) != 0) {
 		switch (ret) {
 		case ENOENT:
 			warn("Cannot find file system superblock");
diff --git a/sbin/growfs/growfs.c b/sbin/growfs/growfs.c
index b75f377841ef..967cda3330d0 100644
--- a/sbin/growfs/growfs.c
+++ b/sbin/growfs/growfs.c
@@ -1449,7 +1449,7 @@ main(int argc, char **argv)
 	/*
 	 * Read the current superblock, and take a backup.
 	 */
-	if ((ret = sbget(fsi, &fs, -1)) != 0) {
+	if ((ret = sbget(fsi, &fs, STDSB)) != 0) {
 		switch (ret) {
 		case ENOENT:
 			errx(1, "superblock not recognized");
diff --git a/sbin/quotacheck/quotacheck.c b/sbin/quotacheck/quotacheck.c
index 3b192a7a9585..9a01be11d9d0 100644
--- a/sbin/quotacheck/quotacheck.c
+++ b/sbin/quotacheck/quotacheck.c
@@ -321,7 +321,7 @@ chkquota(char *specname, struct quotafile *qfu, struct quotafile *qfg)
 		}
 	}
 	sync();
-	if ((ret = sbget(fi, &fs, -1)) != 0) {
+	if ((ret = sbget(fi, &fs, STDSB)) != 0) {
 		switch (ret) {
 		case ENOENT:
 			warn("Cannot find file system superblock");
diff --git a/stand/libsa/ufs.c b/stand/libsa/ufs.c
index 204bc969f968..317d6e9fdb1c 100644
--- a/stand/libsa/ufs.c
+++ b/stand/libsa/ufs.c
@@ -140,6 +140,11 @@ static int	ufs_use_sa_read(void *, off_t, void **, int);
 /* from ffs_subr.c */
 int	ffs_sbget(void *, struct fs **, off_t, char *,
 	    int (*)(void *, off_t, void **, int));
+/*
+ * Request standard superblock location in ffs_sbget
+ */
+#define	STDSB			-1	/* Fail if check-hash is bad */
+#define	STDSB_NOHASHFAIL	-2	/* Ignore check-hash failure */
 
 /*
  * Read a new inode into a file structure.
@@ -519,7 +524,8 @@ ufs_open(upath, f)
 
 	/* read super block */
 	twiddle(1);
-	if ((rc = ffs_sbget(f, &fs, -1, "stand", ufs_use_sa_read)) != 0)
+	if ((rc = ffs_sbget(f, &fs, STDSB_NOHASHFAIL, "stand",
+	     ufs_use_sa_read)) != 0)
 		goto out;
 	fp->f_fs = fs;
 	/*
diff --git a/sys/geom/journal/g_journal_ufs.c b/sys/geom/journal/g_journal_ufs.c
index de0dbd83d48b..028c68079482 100644
--- a/sys/geom/journal/g_journal_ufs.c
+++ b/sys/geom/journal/g_journal_ufs.c
@@ -72,7 +72,7 @@ g_journal_ufs_dirty(struct g_consumer *cp)
 
 	fs = NULL;
 	if (SBLOCKSIZE % cp->provider->sectorsize != 0 ||
-	    ffs_sbget(cp, &fs, -1, M_GEOM, g_use_g_read_data) != 0) {
+	    ffs_sbget(cp, &fs, STDSB, M_GEOM, g_use_g_read_data) != 0) {
 		GJ_DEBUG(0, "Cannot find superblock to mark file system %s "
 		    "as dirty.", cp->provider->name);
 		KASSERT(fs == NULL,
diff --git a/sys/geom/label/g_label_ufs.c b/sys/geom/label/g_label_ufs.c
index b247eaad827d..4c4d43cad0f7 100644
--- a/sys/geom/label/g_label_ufs.c
+++ b/sys/geom/label/g_label_ufs.c
@@ -77,7 +77,7 @@ g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int wh
 
 	fs = NULL;
 	if (SBLOCKSIZE % pp->sectorsize != 0 ||
-	    ffs_sbget(cp, &fs, -1, M_GEOM, g_use_g_read_data) != 0) {
+	    ffs_sbget(cp, &fs, STDSB, M_GEOM, g_use_g_read_data) != 0) {
 		KASSERT(fs == NULL,
 		    ("g_label_ufs_taste_common: non-NULL fs %p\n", fs));
 		return;
diff --git a/sys/ufs/ffs/ffs_extern.h b/sys/ufs/ffs/ffs_extern.h
index d3f6cb597b9a..16f517d5f12e 100644
--- a/sys/ufs/ffs/ffs_extern.h
+++ b/sys/ufs/ffs/ffs_extern.h
@@ -125,6 +125,12 @@ void	process_deferred_inactive(struct mount *mp);
 #define	FFSR_FORCE	0x0001
 #define	FFSR_UNSUSPEND	0x0002
 
+/*
+ * Request standard superblock location in ffs_sbget
+ */
+#define	STDSB			-1	/* Fail if check-hash is bad */
+#define	STDSB_NOHASHFAIL	-2	/* Ignore check-hash failure */
+
 /*
  * Definitions for TRIM interface
  *
diff --git a/sys/ufs/ffs/ffs_subr.c b/sys/ufs/ffs/ffs_subr.c
index e4dbd730b186..64354bbd5383 100644
--- a/sys/ufs/ffs/ffs_subr.c
+++ b/sys/ufs/ffs/ffs_subr.c
@@ -51,6 +51,11 @@ struct malloc_type;
 #define UFS_MALLOC(size, type, flags) malloc(size)
 #define UFS_FREE(ptr, type) free(ptr)
 #define UFS_TIME time(NULL)
+/*
+ * Request standard superblock location in ffs_sbget
+ */
+#define	STDSB			-1	/* Fail if check-hash is bad */
+#define	STDSB_NOHASHFAIL	-2	/* Ignore check-hash failure */
 
 #else /* _KERNEL */
 #include <sys/systm.h>
@@ -139,14 +144,14 @@ ffs_load_inode(struct buf *bp, struct inode *ip, struct fs *fs, ino_t ino)
 	ip->i_gid = dip2->di_gid;
 	return (0);
 }
-#endif /* KERNEL */
+#endif /* _KERNEL */
 
 /*
  * These are the low-level functions that actually read and write
  * the superblock and its associated data.
  */
 static off_t sblock_try[] = SBLOCKSEARCH;
-static int readsuper(void *, struct fs **, off_t, int,
+static int readsuper(void *, struct fs **, off_t, int, int,
 	int (*)(void *, off_t, void **, int));
 
 /*
@@ -177,21 +182,25 @@ ffs_sbget(void *devfd, struct fs **fsp, off_t altsblock,
 	int i, error, size, blks;
 	uint8_t *space;
 	int32_t *lp;
+	int chkhash;
 	char *buf;
 
 	fs = NULL;
 	*fsp = NULL;
-	if (altsblock != -1) {
-		if ((error = readsuper(devfd, &fs, altsblock, 1,
+	chkhash = 1;
+	if (altsblock >= 0) {
+		if ((error = readsuper(devfd, &fs, altsblock, 1, chkhash,
 		     readfunc)) != 0) {
 			if (fs != NULL)
 				UFS_FREE(fs, filltype);
 			return (error);
 		}
 	} else {
+		if (altsblock == STDSB_NOHASHFAIL)
+			chkhash = 0;
 		for (i = 0; sblock_try[i] != -1; i++) {
 			if ((error = readsuper(devfd, &fs, sblock_try[i], 0,
-			     readfunc)) == 0)
+			     chkhash, readfunc)) == 0)
 				break;
 			if (fs != NULL) {
 				UFS_FREE(fs, filltype);
@@ -255,7 +264,7 @@ ffs_sbget(void *devfd, struct fs **fsp, off_t altsblock,
  */
 static int
 readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
-    int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
+    int chkhash, int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
 {
 	struct fs *fs;
 	int error, res;
@@ -285,8 +294,9 @@ readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
 		if (fs->fs_ckhash != (ckhash = ffs_calc_sbhash(fs))) {
 #ifdef _KERNEL
 			res = uprintf("Superblock check-hash failed: recorded "
-			    "check-hash 0x%x != computed check-hash 0x%x\n",
-			    fs->fs_ckhash, ckhash);
+			    "check-hash 0x%x != computed check-hash 0x%x%s\n",
+			    fs->fs_ckhash, ckhash,
+			    chkhash == 0 ? " (Ignored)" : "");
 #else
 			res = 0;
 #endif
@@ -297,7 +307,14 @@ readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
 			if (res == 0)
 				printf("Superblock check-hash failed: recorded "
 				    "check-hash 0x%x != computed check-hash "
-				    "0x%x\n", fs->fs_ckhash, ckhash);
+				    "0x%x%s\n", fs->fs_ckhash, ckhash,
+				    chkhash == 0 ? " (Ignored)" : "");
+			if (chkhash == 0) {
+				fs->fs_flags |= FS_NEEDSFSCK;
+				fs->fs_fmod = 1;
+				return (0);
+			}
+			fs->fs_fmod = 0;
 			return (EINVAL);
 		}
 		/* Have to set for old filesystems that predate this field */
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 9670d6217e86..7cb81cfa450a 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -774,6 +774,7 @@ ffs_mountfs(devvp, mp, td)
 	struct g_consumer *cp;
 	struct mount *nmp;
 	int candelete;
+	off_t loc;
 
 	fs = NULL;
 	ump = NULL;
@@ -810,9 +811,11 @@ ffs_mountfs(devvp, mp, td)
 		goto out;
 	}
 	/* fetch the superblock and summary information */
-	if ((error = ffs_sbget(devvp, &fs, -1, M_UFSMNT, ffs_use_bread)) != 0)
+	loc = STDSB;
+	if ((mp->mnt_flag & MNT_ROOTFS) != 0)
+		loc = STDSB_NOHASHFAIL;
+	if ((error = ffs_sbget(devvp, &fs, loc, M_UFSMNT, ffs_use_bread)) != 0)
 		goto out;
-	fs->fs_fmod = 0;
 	/* none of these types of check-hashes are maintained by this kernel */
 	fs->fs_metackhash &= ~(CK_INODE | CK_INDIR | CK_DIR);
 	/* no support for any undefined flags */
diff --git a/usr.sbin/fstyp/ufs.c b/usr.sbin/fstyp/ufs.c
index 340119dada4c..4002fc89c9ee 100644
--- a/usr.sbin/fstyp/ufs.c
+++ b/usr.sbin/fstyp/ufs.c
@@ -50,7 +50,7 @@ fstyp_ufs(FILE *fp, char *label, size_t labelsize)
 {
 	struct fs *fs;
 
-	switch (sbget(fileno(fp), &fs, -1)) {
+	switch (sbget(fileno(fp), &fs, STDSB)) {
 	case 0:
 		strlcpy(label, fs->fs_volname, labelsize);
 		return (0);
diff --git a/usr.sbin/quot/quot.c b/usr.sbin/quot/quot.c
index 348946ff7dbb..18b1e398ec09 100644
--- a/usr.sbin/quot/quot.c
+++ b/usr.sbin/quot/quot.c
@@ -550,7 +550,7 @@ quot(char *name, char *mp)
 		close(fd);
 		return;
 	}
-	switch (sbget(fd, &fs, -1)) {
+	switch (sbget(fd, &fs, STDSB)) {
 	case 0:
 		break;
 	case ENOENT: