glabel(8) outputs no error when there is no glabel

E

Erichans

When creating gpt partitions on a USB flash drive, glabel(8) behaves unexpectedly (repeatable behaviour):
Code: 
[1] # gpart destroy -F da0
da0 destroyed
[2] # gpart create -s gpt da0
da0 created
[3] # gpart add -t freebsd-ufs -l FreeBLAH da0
da0p1 added
[4] # glabel dump da0p1
Can't read metadata from da0p1: Invalid argument.
glabel: Not fully done.
[5] # glabel stop Free-BLAH
glabel: Label Free-BLAH is invalid.
[6] # glabel stop FreeBLAH
[7] # echo $?
0
[8] # glabel stop FreeBLAH
glabel: Label FreeBLAH is invalid.
[9] # echo $?
1
Cmd #4 shows (as expected) that there is no glabel data on da0p1.
Cmd #5 is an intentionally made typo (the extra "-" in the glabel argument); its result is as expected.
Cmd #6 should output an error message; like cmd #8.

What is happening?


Code: 
% uname -a
FreeBSD q210 12.3-RELEASE-p5 FreeBSD 12.3-RELEASE-p5 GENERIC  amd64
 
Erichans said:
[1] # gpart destroy -F da0 da0 destroyed
Click to expand...
Personally step 2 for me is dd.
I know its rough on the disk but I want it zeroed.
You might need to enable some /boot/loader.conf settings (& reboot) to clear old labels :
Code: 
kern.geom.label.ufsid.enable=0
kern.geom.label.gptid.enable=0
kern.geom.label.gpt.enable=0
Then after zeroing USB device disable or delete these settings.
These settings disable labels that get stored in /dev so you can fully wipe a disk.
 
Thanks. My experimentation started with grahamperrin@'s message and his pastebin output:
[...]
root@mowa219-gjp4-8570p-freebsd:~ # glabel stop FreeBSD%20ZFS
root@mowa219-gjp4-8570p-freebsd:~ # gpart show -l da1
Click to expand...
I couldn't explain the absence of an error message as a result of the first command; so I took a brand-new USB stick.

Phishfry said:
Personally step 2 for me is dd.
Click to expand...
I tried dd as well: no effect. I also tried another brand-new USB stick, same results, see below.

Phishfry said:
I am not sure but you should look at tunefs -p as well for investigation. See what label shows up there.
Try changing the label with tunefs -L . Revert to single user mode if really stubborn.
Click to expand...
tunefs(8) is about UFS specific labels. I haven't touched those at all; also used two new USB sticks.

Phishfry said:
Erichans said:
Cmd #4 shows (as expected) that there is no glabel data on da0p1.
Click to expand...
Why not? In step #3 you explicitly add a partition with -l FreeBLAH
Click to expand...
[3] # gpart add -t freebsd-ufs -l FreeBLAH da0 adds a gpt label.
[4] # glabel dump da0p1 (tries to) dump metadata (of glabels) stored on the given devices.
GEOM (glabel) labels (as in glabel label blurp ada0s1b) are not the same as gpt labels. In addition to that no entries appear in /dev/label*

AFAIK, glabel labels can only be set with glabel(8)—or geom label—and glabel(8) cannot set gpt labels. gpt labels can be read by glabel(8).

To the best of my knowledge a GEOM label cannot exist without its metadata, whether it is turned on or off, or whether it is made invisible by geom withering. Cmd #4 confirms that there isn't any glabel metadata on da0p1.

Cmd #5 is not strictly necessary to show the unexpected behaviour. It only serves as a contrast to the next cmd #6. glabel(1) should be able to handle a normal "-" (dash) quite well IMO. However the typo with the "-" replaced by an "x" yields the same result.

The second new USB stick (same make and model) fresh from its package shows the same results:
Code: 
[10] # dd if=/dev/zero of=/dev/da0 bs=512 count=10
10+0 records in
10+0 records out
5120 bytes transferred in 0.136022 secs (37641 bytes/sec)
[11] # gpart destroy -F da0
da0 destroyed
[12] # gpart create -s gpt da0
da0 created
[13] # gpart add -t freebsd-ufs -l FreeBLAH da0
da0p1 added
[14] # glabel dump da0p1
Can't read metadata from da0p1: Invalid argument.
glabel: Not fully done.
[15] # glabel stop FreexBLAH
glabel: Label FreexBLAH is invalid.
[16] # glabel stop FreeBLAH
[17] # glabel stop FreeBLAH
glabel: Label FreeBLAH is invalid.
 
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