XXX: Current code may have problems if kernel memory is completely depleted.
This is, unfortunately, not the only chunk of RAIDframe code to have
this problem, and will have to be dealt with. :(
rework how completed requests are handled. In particular, instead of
doing all sorts of work and locking in interrupt context, completed
requests are now queued. A new kernel thread (rf_RaidIOThread) now
handles calling rf_DiskIOComplete() and (req->CompleteFunc)() for each
completed request. There is still work to be done to make RAIDframe
LOCKDEBUG friendly, but this change is a huge step forward.
Reviewed by (and many thanks to): thorpej
the stuff that used to live in rf_types.h, rf_raidframe.h, rf_layout.h,
rf_netbsd.h, rf_raid.h, rf_decluster,h, and a few other places.
Believe it or not, when this is all done, things will be cleaner.
No functional changes to RAIDframe.
of a real component failure (or a simulated failure):
- add 'numNewFailures' to keep track of the number of disk failures
since mod_counter was last updated for each component label.
- make sure we call rf_update_component_labels() upon any component failure,
real or simulated.
- make current default label values available everywhere
- make sure numBlocks and blockSize in component labels get initialized
for all component labels
- check for component size to be smaller than or equal to the partition size
when autoconfiguring
- make component_label variables more consistent (==> clabel)
- re-work incorrect component configuration code
- re-work disk configuration code
- cleanup initial configuration of raidPtr info
- add auto-detection of components and RAID sets (Disabled, for now)
- allow / on RAID sets (Disabled, for now)
- rename "config_disk_queue" to "rf_ConfigureDiskQueue" and properly prototype
in rf_diskqueue.h
- protect some headers with #if _KERNEL (XXX this needs to be fixed properly)
and cleanup header formatting.
- expand the component labels (yes, they should be backward/forward compatible)
- other bits and pieces (some function names are still bogus, and will get
changed soon)
- fire up a new thread for parity re-writes, copybacks, and reconstructs.
The ioctl's which trigger these actions now return immediately.
- add progress accounting for the above actions.
- minor rototillage of rf_netbsdkintf.c to deal with all of the above.
RAIDframe driver to stop it from eating too much kernel memory when
writing data. But that fix had a nasty side-affect of hurting write
performance (*much* more than I thought it would). These changes nuke
that "fix", and instead put in a more reasonable mechanism for limiting
the number of simultaneous IO's which can be happening for each RAID device.
The result is a noticeable improvement in write throughput. The End.
out-dated comments, and other unneeded stuff. This helps prepare
for cleaning up the rest of the code, and adding new functionality.
No functional changes to the kernel code in this commit.
Carnegie Mellon University. Full RAID implementation, including
levels 0, 1, 4, 5, 6, parity logging, and a few other goodies.
Ported to NetBSD by Greg Oster.
