See previous commit for details. But the gist is with the removal of
the zvol path component the regression tests must be updated to use
the correct path name.
As part of commit f162433deb the /zvol/
path component was added for zvol devices. This ensured all zvol
devices would be created by udev in /dev/zvol/<pool>/<dataset>, as
opposed to the previous /dev/<pool>/<dataset> path. Logically, it
was nice to organize them in a directory much like Solaris does.
However, while initial testing showed this to work fine with modern
kernels it does not appear to be supported under RHEL5. The extra
path component triggers a NULL deref in create_dir(). Anyway, to
avoid having different zvol path names based on your kernel version
its more consistent simply to revert to the original naming convention.
If you really want the zvol component you can always add custom
udev rules to do exactly this.
We can revisiting this change again once we are willing to drop
support for RHEL5 and similar older distros.
I've noticed the TopGit linux-zfs-branch has some linux-kernel-mem
changes which were incorrectly merged. To fix the issue I'm
reverting the changes in the linux-kernel-mem topic branch, then
remerging the revert, and finally reapplying and merging the
change correctly.
This reverts commit 421d95b3ea.
Ricardo correctly pointed out that there is more going on here than
typecasting. By removing the locals we are actually causing LEFT and
RIGHT to be evaluated twice which can potentially lead to some
strange side effects as:
1) VERIFY3*() causing a panic but in the panic message the values
look correct such that the assertion shouldn't fail, or:
2) if LEFT or RIGHT are expressions with side-effects (e.g. a call
to a function which changes some state), then when we panic and
examine the crash dump, it may lead to an unexpected state because
we are not expecting certain things to change during the panic,
after the expressions inside VERIFY3*(...) have been evaluated.
3) Also, it may lead to double-panics or deadlocks during panics,
like for example, if the expressions inside VERIFY3*(...) only expect
to be called once (e.g. because they acquire a mutex).
Brian Behlendorf