NAME_ERR_DISKLIKE is Solaris specific in module/zcommon/zfs_namecheck.c

[blastwave]

Looking at module/zcommon/zfs_namecheck.c at line 453 we see :

   453    if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
   454        if (why)
   455            *why = NAME_ERR_DISKLIKE;
   456        return (-1);
   457    }

The end result is that zpool create with a name like "c0" fails for 
no valid reason.  Certainly on FreeBSD this has been an issue for some
time now : 

    ZFS NAME_ERR_DISKLIKE check is Solaris-specific
    https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=159356

Should be a trivial fix. 

The alternative would be a pile of ifdef and checking for things like
ada0 and da0 and sda0.  Perhaps these days are in the distant history
and the error NAME_ERR_DISKLIKE may not be reasonable anymore.


-- 
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken
GreyBeard and suspenders optional

[blastwave]

I have done some testing on FreeBSD current and there seems to be no valid reason to restrict the zpool names away from "c[0-9]" type strings. I did create and destroy c0ffee as well as the obvious c0. Seems all to work just fine of course :

europa# 
europa# zpool create -o cachefile=/boot/zfs/zpool.cache -m none -O compress=zstd -O checksum=sha512 -O atime=on -O xattr=on -o autoexpand=on -o autoreplace=on -o failmode=continue -o listsnaps=on -O dedup=off -O copies=1 -O canmount=off -m none c0ffee mirror ada3p1 ada2p1 
europa# zpool list
NAME     SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
c0ffee   464G   176K   464G        -         -     0%     0%  1.00x    ONLINE  -
z0      95.5G  18.9G  76.6G        -         -     8%    19%  1.00x    ONLINE  -
europa# 
europa# 
europa# zpool destroy c0ffee
europa# 
europa# 
europa# zpool create -o cachefile=/boot/zfs/zpool.cache -m none -O compress=zstd -O checksum=sha512 -O atime=on -O xattr=on -o autoexpand=on -o autoreplace=on -o failmode=continue -o listsnaps=on -O dedup=off -O copies=1 -O canmount=off -m none c0 mirror ada3p1 ada2p1
europa# zpool list
NAME   SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
c0     464G   162K   464G        -         -     0%     0%  1.00x    ONLINE  -
z0    95.5G  18.9G  76.6G        -         -     8%    19%  1.00x    ONLINE  -
europa# 
.
.
.
europa# zfs recv -Fvu c0 < /var/tmp/root/z1_20210323231220.capR
receiving full stream of z1@20210301132814 into c0@20210301132814
received 46.0K stream in 1 seconds (46.0K/sec)
receiving incremental stream of z1@20210311172455 into c0@20210311172455
received 312B stream in 1 seconds (312B/sec)
receiving incremental stream of z1@20210323231220 into c0@20210323231220
received 312B stream in 1 seconds (312B/sec)
receiving full stream of z1/usr@20210301132814 into c0/usr@20210301132814
received 46.0K stream in 1 seconds (46.0K/sec)
receiving incremental stream of z1/usr@20210311172455 into c0/usr@20210311172455
received 312B stream in 1 seconds (312B/sec)
.
.
.
receiving full stream of z1/freebsd_src@20210323231220 into c0/freebsd_src@20210323231220
received 3.28G stream in 50 seconds (67.1M/sec)
europa# zfs list -r -t all c0 
NAME                            USED  AVAIL     REFER  MOUNTPOINT
c0                             12.7G   437G       24K  none
c0@20210301132814                 0B      -       24K  -
c0@20210311172455                 0B      -       24K  -
c0@20210323231220                 0B      -       24K  -
c0/freebsd_src                 2.33G   437G     2.33G  /usr/src
c0/freebsd_src@20210323231220     0B      -     2.33G  -
c0/opt                         6.35G   437G     8.40M  /opt
c0/opt@20200930084425            28K      -     8.28M  -
c0/opt@20200930093340            28K      -     8.28M  -
c0/opt@20201219110739           123K      -     8.41M  -
c0/opt@20210117031410           123K      -     8.41M  -
c0/opt@20210121200001           125K      -     8.40M  -
c0/opt@20210130051352           124K      -     8.40M  -
c0/opt@20210220023743           124K      -     8.40M  -
c0/opt@20210301132814           123K      -     8.40M  -
c0/opt@20210311172455           124K      -     8.40M  -
c0/opt@20210315070355           123K      -     8.39M  -
c0/opt@20210323231220             0B      -     8.40M  -
c0/opt/bw                      6.32G   437G     6.09G  /opt/bw
c0/opt/bw@20200930084425          0B      -     1.52G  -
c0/opt/bw@20200930093340          0B      -     1.52G  -
c0/opt/bw@20201219110739       5.66M      -     1.75G  -
c0/opt/bw@20210117031410        212K      -     4.16G  -
c0/opt/bw@20210117194637        154K      -     4.16G  -
c0/opt/bw@20210121200001       10.7M      -     4.16G  -
c0/opt/bw@20210130051352       10.8M      -     4.16G  -
c0/opt/bw@20210220023743       10.7M      -     4.16G  -
c0/opt/bw@20210301132814       71.9M      -     4.54G  -
c0/opt/bw@20210311172455       18.0M      -     6.09G  -
c0/opt/bw@20210315070355       18.0M      -     6.09G  -
c0/opt/bw@20210323231220          0B      -     6.09G  -
c0/test                          36K   437G       36K  /var/tmp/test
c0/test@20210323231220            0B      -       36K  -
c0/usr                         4.00G   437G       24K  none
c0/usr@20210301132814             0B      -       24K  -
c0/usr@20210311172455             0B      -       24K  -
c0/usr@20210323231220             0B      -       24K  -
c0/usr/home                    4.00G   437G     3.01G  /usr/home
c0/usr/home@20200930084425     52.5K      -      569M  -
c0/usr/home@20200930093340     53.5K      -      569M  -
c0/usr/home@20201219110740     3.32M      -     2.81G  -
c0/usr/home@20210117031410     4.04M      -     2.89G  -
c0/usr/home@20210121200001     4.08M      -     2.89G  -
c0/usr/home@20210130051352     4.07M      -     2.89G  -
c0/usr/home@20210220023743      160K      -     2.89G  -
c0/usr/home@20210301132814      161K      -     2.88G  -
c0/usr/home@20210311172455     3.88M      -     2.88G  -
c0/usr/home@20210323231220        0B      -     3.01G  -
europa# 
europa# zpool status c0
  pool: c0
 state: ONLINE
config:

        NAME        STATE     READ WRITE CKSUM
        c0          ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ada3p1  ONLINE       0     0     0
            ada2p1  ONLINE       0     0     0

errors: No known data errors
europa# zpool scrub c0 
europa# 
europa# zpool status c0
  pool: c0
 state: ONLINE
  scan: scrub repaired 0B in 00:03:57 with 0 errors on Wed Mar 24 00:48:42 2021
config:

        NAME        STATE     READ WRITE CKSUM
        c0          ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ada3p1  ONLINE       0     0     0
            ada2p1  ONLINE       0     0     0

errors: No known data errors
europa# 

Seems to all be wonderful.

Would you like to open a pull request? Otherwise I'm happy to take care of it.

[blastwave]

Please feel free to make this itty bitty teeny little comment happen such that we can all have c0ffee zpools.
Thus :

Index: sys/contrib/openzfs/module/zcommon/zfs_namecheck.c 
===================================================================
--- sys/contrib/openzfs/module/zcommon/zfs_namecheck.c 
+++ sys/contrib/openzfs/module/zcommon/zfs_namecheck.c 
@@ -450,11 +450,16 @@
                return (-1);
        }
 
+       /* We really do not need this historical artifact 
+        *  as this was entirely a Solaris and OpenSolaris concern 
+        * Dennis Clarke dclarke@blastwave.org
+        *
        if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
                if (why)
                        *why = NAME_ERR_DISKLIKE;
                return (-1);
        }
+       */
 
        return (0);
 }


Given that I have a passing familiarity with this Solaris thing I can
say that we really never should have checked for c[0-9] type names and
just let the sysadmin do what they do. After all, UNIX and Linux does
not wrap the root user in cotton balls to protect them from themselves. 

-- 
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken
GreyBeard and suspenders optional