Index: sbin/growfs/growfs.8
===================================================================
--- sbin/growfs/growfs.8
+++ sbin/growfs/growfs.8
@@ -89,6 +89,12 @@
 .Nm
 will enlarge the file system to the size of the entire partition).
 .El
+.Sh EXIT STATUS
+Exit status is 0 on success, and > 1 on errors.
+.Nm
+exits with 1 on harmless errors, for instance, when it has nothing to do.
+Errors recoverable by user action are signalled with 2.
+OS errors, which are usually not recoverable, are signaled with 3, or greater.
 .Sh EXAMPLES
 Expand root file system to fill up available space:
 .Dl growfs /
Index: sbin/growfs/growfs.c
===================================================================
--- sbin/growfs/growfs.c
+++ sbin/growfs/growfs.c
@@ -150,7 +150,7 @@
 	 */
 	fscs = (struct csum *)calloc((size_t)1, (size_t)sblock.fs_cssize);
 	if (fscs == NULL)
-		errx(1, "calloc failed");
+		errx(3, "calloc failed");
 	memcpy(fscs, osblock.fs_csp, osblock.fs_cssize);
 	free(osblock.fs_csp);
 	osblock.fs_csp = NULL;
@@ -262,7 +262,7 @@
 	 * and all the alternates back to disk.
 	 */
 	if (!Nflag && sbput(fso, &sblock, sblock.fs_ncg) != 0)
-		errc(2, EIO, "could not write updated superblock");
+		errc(3, EIO, "could not write updated superblock");
 	DBG_PRINT0("fscs written\n");
 
 #ifdef FS_DEBUG
@@ -1405,7 +1405,7 @@
 				size <<= 30;
 				size <<= 10;
 			} else
-				errx(1, "unknown suffix on -s argument");
+				errx(2, "unknown suffix on -s argument");
 			break;
 		case 'v': /* for compatibility to newfs */
 			break;
@@ -1429,25 +1429,25 @@
 	 */
 	device = getdev(*argv);
 	if (device == NULL)
-		errx(1, "cannot find special device for %s", *argv);
+		errx(2, "cannot find special device for %s", *argv);
 
 	statfsp = dev_to_statfs(device);
 
 	fsi = open(device, O_RDONLY);
 	if (fsi < 0)
-		err(1, "%s", device);
+		err(3, "%s", device);
 
 	/*
 	 * Try to guess the slice size if not specified.
 	 */
 	if (ioctl(fsi, DIOCGMEDIASIZE, &mediasize) == -1)
-		err(1,"DIOCGMEDIASIZE");
+		err(3,"DIOCGMEDIASIZE");
 
 	/*
 	 * Check if that partition is suitable for growing a file system.
 	 */
 	if (mediasize < 1)
-		errx(1, "partition is unavailable");
+		errx(2, "partition is unavailable");
 
 	/*
 	 * Read the current superblock, and take a backup.
@@ -1455,9 +1455,9 @@
 	if ((ret = sbget(fsi, &fs, STDSB)) != 0) {
 		switch (ret) {
 		case ENOENT:
-			errx(1, "superblock not recognized");
+			errx(2, "superblock not recognized");
 		default:
-			errc(1, ret, "unable to read superblock");
+			errc(3, ret, "unable to read superblock");
 		}
 	}
 	/*
@@ -1465,7 +1465,7 @@
 	 */
 	if (fs->fs_clean == 0 ||
 	    (fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) != 0)
-		errx(1, "%s is not clean - run fsck.\n", *argv);
+		errx(2, "%s is not clean - run fsck.\n", *argv);
 	memcpy(&osblock, fs, fs->fs_sbsize);
 	free(fs);
 	memcpy((void *)&fsun1, (void *)&fsun2, osblock.fs_sbsize);
@@ -1486,7 +1486,7 @@
 			    mediasize,
 			    "B", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
 
-			errx(1, "requested size %s is larger "
+			errx(2, "requested size %s is larger "
 			    "than the available %s", oldsizebuf, newsizebuf);
 		}
 	}
@@ -1515,7 +1515,7 @@
 	 * Are we really growing?
 	 */
 	if (osblock.fs_size >= sblock.fs_size) {
-		errx(1, "we are not growing (%jd->%jd)",
+		errx(3, "we are not growing (%jd->%jd)",
 		    (intmax_t)osblock.fs_size, (intmax_t)sblock.fs_size);
 	}
 
@@ -1525,7 +1525,7 @@
 	if (yflag == 0) {
 		for (j = 0; j < FSMAXSNAP; j++) {
 			if (sblock.fs_snapinum[j]) {
-				errx(1, "active snapshot found in file system; "
+				errx(2, "active snapshot found in file system; "
 				    "please remove all snapshots before "
 				    "using growfs");
 			}
@@ -1570,14 +1570,14 @@
 		if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) == 0) {
 			fso = open(_PATH_UFSSUSPEND, O_RDWR);
 			if (fso == -1)
-				err(1, "unable to open %s", _PATH_UFSSUSPEND);
+				err(3, "unable to open %s", _PATH_UFSSUSPEND);
 			error = ioctl(fso, UFSSUSPEND, &statfsp->f_fsid);
 			if (error != 0)
-				err(1, "UFSSUSPEND");
+				err(3, "UFSSUSPEND");
 		} else {
 			fso = open(device, O_WRONLY);
 			if (fso < 0)
-				err(1, "%s", device);
+				err(3, "%s", device);
 		}
 	}
 
@@ -1586,7 +1586,7 @@
 	 */
 	testbuf = malloc(sblock.fs_fsize);
 	if (testbuf == NULL)
-		err(1, "malloc");
+		err(3, "malloc");
 	rdfs((ufs2_daddr_t)((size - sblock.fs_fsize) / DEV_BSIZE),
 	    sblock.fs_fsize, testbuf, fsi);
 	wtfs((ufs2_daddr_t)((size - sblock.fs_fsize) / DEV_BSIZE),
@@ -1640,7 +1640,7 @@
 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
 
 	if (osblock.fs_size >= sblock.fs_size)
-		errx(1, "not enough new space");
+		errx(3, "not enough new space");
 
 	DBG_PRINT0("sblock calculated\n");
 
@@ -1654,11 +1654,11 @@
 		if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) == 0) {
 			error = ioctl(fso, UFSRESUME);
 			if (error != 0)
-				err(1, "UFSRESUME");
+				err(3, "UFSRESUME");
 		}
 		error = close(fso);
 		if (error != 0)
-			err(1, "close");
+			err(3, "close");
 		if (statfsp != NULL && (statfsp->f_flags & MNT_RDONLY) != 0)
 			mount_reload(statfsp);
 	}