ZFS rename with associated snapshot present: odd error message

[Mark Millard]

On 2021-May-5, at 02:47, Andriy Gapon <avg at FreeBSD.org> wrote:

> On 05/05/2021 01:59, Mark Millard via freebsd-current wrote:
>> I had a:
>> # zfs list -tall
>> NAME                                       USED  AVAIL     REFER  MOUNTPOINT
>> . . .
>> zroot/DESTDIRs/13_0R-CA72-instwrld-norm              1.44G   117G       96K  /usr/obj/DESTDIRs/13_0R-CA72-instwrld-norm
>> zroot/DESTDIRs/13_0R-CA72-instwrld-norm at dirty-style  1.44G      -     1.44G  -. . .
>> . . .
>> (copied/pasted from somewhat earlier) and then attempted:
>> # zfs rename zroot/DESTDIRs/13_0R-CA72-instwrld-norm zroot/DESTDIRs/13_0R-CA72-instwrld-alt-0
>> cannot open 'zroot/DESTDIRs/13_0R-CA72-instwrld-norm at dirty-style': snapshot delimiter '@' is not expected here
>> Despite the "cannot open" message, the result looks like:
>> # zfs list -tall
>> NAME                                                       USED  AVAIL     REFER  MOUNTPOINT
>> . . .
>> zroot/DESTDIRs/13_0R-CA72-instwrld-alt-0                  1.44G   114G       96K  /usr/obj/DESTDIRs/13_0R-CA72-instwrld-alt-0
>> zroot/DESTDIRs/13_0R-CA72-instwrld-alt-0 at dirty-style      1.44G      -     1.44G  -
>> . . .
>> Still, it leaves me wondering if everything is okay
>> given that internal attempt to use the old name with
>> @dirty-style when it was apparently no longer
>> available under that naming.
>> For reference:
>> # uname -apKU
>> FreeBSD CA72_4c8G_ZFS 13.0-RELEASE FreeBSD 13.0-RELEASE #0 releng/13.0-n244733-ea31abc261ff-dirty: Thu Apr 29 21:53:20 PDT 2021     root at CA72_4c8G_ZFS:/usr/obj/BUILDs/13_0R-CA72-nodbg-clang/usr/13_0R-src/arm64.aarch64/sys/GENERIC-NODBG-CA72  arm64 aarch64 1300139 1300139
> 
> Cannot reproduce here (but with much simpler names and on stable/13):
> zfs create testz/test
> zfs snapshot testz/test at snap1
> zfs rename testz/test testz/test2
> 
> All worked.
> 

I've noticed that sometimes in my explorations it has been
silent instead of complaining. I've no clue at this point
what prior activity (or lack of activity) makes the
difference for if a message will be generated vs. not.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)