Hi tech@, When I had to change a HD between machines I figured out that -P option of mount_mfs(8) does not work with DUIDs:
# mount_mfs -P ca7552589896b01e.d swap /mnt mount_mfs: cannot stat ca7552589896b01e.d: No such file or directory mount_mfs(8) already allows a DUID as the `special` argument, it is not documented though. The patch bellow allow using -P with a DUID as block device. Important: I used the same approach used in the code (pointer swap) to resolve DUID to device using opendev(3). But after the patch there will be two opendev(3) calls with non-NULL realpath, and as manpage states the stored path is overwritten by subsequent calls. It took some time of code reading and rereading until I convinced myself that there is no problem in this *specific* situation. However, I think that should be safier to use malloc(size = PATH_MAX) + strlcpy() on `pop` and `special`. That way, code refactoring doesn't to care about the relative position of the opendev(3) calls. What do you think? Comments? Patch: (available too at: https://www.diskless.io/openbsd/newfs.patch) Index: sbin/newfs/newfs.8 =================================================================== RCS file: /cvs/src/sbin/newfs/newfs.8,v retrieving revision 1.74 diff -u -p -r1.74 newfs.8 --- sbin/newfs/newfs.8 17 Mar 2016 07:18:34 -0000 1.74 +++ sbin/newfs/newfs.8 7 Apr 2019 05:49:13 -0000 @@ -293,7 +293,9 @@ is a directory, populate the created mfs contents of the directory. If .Ar file -is a block device, populate the created mfs file system with the +is a block device or a +.Xr disklabel 8 +UID (DUID), populate the created mfs file system with the contents of the FFS file system contained on the device. .El .Pp Index: sbin/newfs/newfs.c =================================================================== RCS file: /cvs/src/sbin/newfs/newfs.c,v retrieving revision 1.111 diff -u -p -r1.111 newfs.c --- sbin/newfs/newfs.c 25 Nov 2018 17:12:10 -0000 1.111 +++ sbin/newfs/newfs.c 7 Apr 2019 05:49:13 -0000 @@ -174,7 +174,7 @@ main(int argc, char *argv[]) struct stat st; struct statfs *mp; struct rlimit rl; - int fsi = -1, oflagset = 0, fso, len, n, maxpartitions; + int fsi = -1, oflagset = 0, fso, fp, fd, len, n, maxpartitions; char *cp = NULL, *s1, *s2, *special, *opstring, *realdev; #ifdef MFS char mountfromname[BUFSIZ]; @@ -526,6 +526,16 @@ havelabel: args.export_info.ex_flags = MNT_EXRDONLY; if (mntflags & MNT_NOPERM) mntflags |= MNT_NODEV | MNT_NOEXEC; + + if (pop != NULL && isduid(pop, 0)) { + /* Resolve DUID to block device */ + fd = opendev(pop, O_RDONLY, OPENDEV_BLCK, &realdev); + if (fd < 0) + err(1, "could not open %s", pop); + + close(fd); + pop = realdev; + } switch (pid = fork()) { case -1:
