rf_PrintUserStats() was mean for the simulator, and doesn't provide
any real info in kernel-space, especially for reconstructs.
Reconstructing actually renders the stats even more useless, since it
resets them all to zero before the reconstruct starts!
- since rf_PrintUserStats() is no longer used, nuke it along with the
routines that feed it. Nothing was using this code, and if we ever
need it again, we know where to find it.
dynamically allocated variable-sized array (dagArray). Convert code
to use the new linked list stuff instead of the array stuff (the ratio
of one dagList per stripe still applies). The big advantage is in
being able to more efficiently allocate the dagLists on-the-fly, and
not have to know the size(s) of the array beforehand.
~forever. This requires a number of things:
1) If we can't create a DAG, set desc->numStripes to 0 in
rf_SelectAlgorithm. This will ensure that we don't attempt to free
any dagArray[] elements in rf_StateCleanup.
2) Modify rf_State_CreateDAG() to not panic in the event of a DAG
failure. Instead, set the bp->b_flags and bp->b_error, and set things
up to skip to rf_State_Cleanup().
3) Need to mark desc->status as "bad" so that we actually stop looking
for a different DAG. (which we won't find... no matter how many times
we try).
4) rf_State_LastState() will then do the biodone(), and return EIO for
the IO in question.
5) Remove some " || 1 "'s from ProcessNode(). These were for
debugging, and we don't need the failure notices spewing
over and over again as the failing DAGs are processed.
6) Needed to change
if (asmap->numDataFailed + asmap->numParityFailed > 1)
to
if ((asmap->numDataFailed + asmap->numParityFailed > 1) ||
(raidPtr->numFailures > 1)){
in rf_raid5.c so that it doesn't try to return
rf_CreateNonRedundantWriteDAG as the creation function.
7) Note that we can't apply the above change to the RAID 1 code as
with the silly "fake 2-D" RAID 1 sets, it is possible to have 2 failed
components in the RAID 1 set, and that would stop them from working.
(I really don't know why/how those "fake 2-D" RAID 1 sets even work
with all the "single-fault" assumptions present in the rest of the
code.)
8) Needed to protect rf_RAID0DagSelect() in a similar way -- it should
return NULL as the createFunc.
9) No point printing out "Multiple disks failed..." a zillion times.
RF_DAG_RETURN_DAG
RF_DAG_RETURN_ASM
RF_DAG_TEST_ACCESS
and the code that goes with them. A couple more of these
can probably go too, but I might need them in a bit.
was just an accident in the first place. Cleanup function decls and
a few comments. [ok.. so I wasn't going to fix this many.. but once
you're on a roll....]
of strenuous agreement, and some general agreement, this commit is
going ahead because it's now starting to block some other changes I
wish to make.]
Remove most of the support for the concept of "rows" from RAIDframe.
While the "row" interface has been exported to the world, RAIDframe
internals have really only supported a single row, even though they
have feigned support of multiple rows.
Nothing changes in configuration land -- config files still need to
specify a single row, etc. All auto-config structures remain fully
forward/backwards compatible.
The only visible difference to the average user should be a
reduction in the size of a GENERIC kernel (i386) by 4.5K. For those
of us trolling through RAIDframe kernel code, a lot of the driver
configuration code has become a LOT easier to read.
reported by 'systat iostat' and friends are now much more correct for
RAIDframe devices. Thanks to Andrew Doran for poking me about this,
and for suggestions on and review of the changes.
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.
reads. This avoids a problem where many writes will cause the driver
to allocate way too much memory.
This needs to change to a queueing system later, which will provide a
way to limit the memory consumed by the driver.
Without these changes, raidframe would use 24M or more on my machine when
the buffer cache dumped all its dirty blocks. Now it uses around 200k
or so.
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.
