MFC r341390, r341392, r341667

r341390:
Remove some dead code from the geli tests

This is detritus in the Makefile, leftover from 327662.

r341392:
Unbreak geli/gmirror testcases if their geom classes cannot be loaded

The problem with the logic prior to this commit was twofold:

1. The wrong set of idioms (TAP-compatible) were being applied to the ATF
testcases when run, resulting in confusing ATF failure results on setup.
2. The cleanup subroutines were broken when the geom classes could not be
loaded as they exited with 0 unexpectedly.

This commit changes the test code to source the class-specific configuration
(conf.sh) once globally, instead of sourcing it per testcase and per cleanup
subroutine, and to call the ATF-specific setup subroutine(s) inline in
the testcases.

The refactoring done is effectively a no-op for the TAP testcases, modulo
any refactoring done to create common code between the ATF and TAP
testcases.

This unbreaks the geli testcases converted to ATF in r327662 and r327683,
and the gmirror testcases added in r327780, respectively, when the geom
class could not be loaded.

tests/sys/geom/class/mirror/...
While here, ignore errors when turning debug failpoint sysctl off, which
could occur if the gmirror class was not loaded.

Submitted by: ngie
Pull Request: https://github.com/freebsd/freebsd/pull/241

r341667:
geom tests: Fix cleanup of ATF tests since r341392

r341392 changed common test cleanup routines in a way that allowed them to
be used by TAP tests as well as ATF tests. However, a late change made
during code review resulted in cleanup being broken for ATF tests, which
source geom_subr.sh separately during the body and cleanup phases of the
test. The result was that md(4) devices wouldn't get cleaned up.

X-MFC-With: 341392

MFC r329273, r329275, r329277, r329284, r329344

r329273:
geli: append "/eli" to the underlying provider's physical path

If the underlying provider's physical path is null, then the geli device's
physical path will be, too. Otherwise, it will append "/eli". This will make
geli work better with zfsd(8).

PR: 224962
Differential Revision: https://reviews.freebsd.org/D13979

r329275:
gpart: append partition name to the underlying provider's physical path

If the underlying provider's physical path is null, then the gpart device's
physical path will be, too. Otherwise, it will append the partition name,
such as "/p1" or "/s1/a". This will make gpart work better with zfsd(8).

PR: 224965
Differential Revision: https://reviews.freebsd.org/D14010

r329277:
Add mtree entry for 329275

X-MFC-With: 329275
Sponsored by: Spectra Logic Corp

r329284:
zfsd: Allow zfsd to work on any type of GEOM provider

cddl/usr.sbin/zfsd/zfsd_event.cc
Remove the check for da and ada devices. This way zfsd can work on md,
geli, glabel, gstripe, etc devices. geli in particular is useful
combined with ZFS. gnop is also useful for simulating drive pulls in
the ZFSD test suite.

Also, eliminate the DevfsEvent class entirely. Move its
responsibilities into GeomEvent. We can get everything we need to know
just from listening to GEOM events.

lib/libdevdctl/event.cc
Fix GeomEvent::DevName for CREATE events. Oddly, the relevant field is
named "cdev" for CREATE events but "devname" for disk events.

Relnotes: Yes (probably worth mentioning the geli part)
Sponsored by: Spectra Logic Corp

r329344:
Optimize zfsd for the happy case

If there are no damaged pools, then ignore all GEOM events. We only use
them to fix damaged pools. However, still pay attention to ZFS events.

X-MFC-With: 329284
Sponsored by: Spectra Logic Corp