Module Name:	src
Committed By:	tron
Date:		Sun Apr 11 11:19:08 UTC 2004

Modified Files:
	src/sys/dev/raidframe [netbsd-2-0]: rf_dagutils.h

Log Message:
Pull up revision 1.17 (requested by oster in ticket #123):
These changes complete the effective removal of malloc() from all
write paths within RAIDframe.  They also resolve the "panics with
RAID 5 sets with more than 3 components" issue which was present
(briefly) in the commits which were previously supposed to address
the malloc() issue.
With this new code the 5-component RAID 5 set panics are now gone.
It is also now also possible to swap to RAID 5.
The changes made are:
1) Introduce rf_AllocStripeBuffer() and rf_FreeStripeBuffer() to
allocate/free one stripe's worth of space.  rf_AllocStripeBuffer() is
used in rf_MapUnaccessedPortionOfStripe() where it is not sufficient to
allocate memory using just rf_AllocBuffer().  rf_FreeStripeBuffer() is
called from rf_FreeRaidAccDesc(), well after the DAG is finished.
2) Add a set of emergency "stripe buffers" to struct RF_Raid_s.
Arrange for their initialization in rf_Configure().  In low-memory
situations these buffers will be returned by rf_AllocStripeBuffer()
and re-populated by rf_FreeStripeBuffer().
3) Move	RF_VoidPointerListElem_t *iobufs from the dagHeader into
into struct RF_RaidAccessDesc_s.  This is more consistent with the
original code, and will not result in items being freed "too early".
4) Add a RF_RaidAccessDesc_t *desc to RF_DagHeader_s so that we have a
way to find desc->iobufs.
5) Arrange for desc in the DagHeader to be initialized in InitHdrNode().
6) Don't cleanup iobufs in rf_FreeDAG() -- the freeing is now delayed
until rf_FreeRaidAccDesc() (which is how the original code handled the
allocList, and for which there seem to be some subtle, undocumented
assumptions).
7) Rename rf_AllocBuffer2() to be rf_AllocBuffer() and remove the
former rf_AllocBuffer().  Fix all callers of rf_AllocBuffer().
(This was how it was *supposed* to be after the last time these
changes were made, before they were backed out).
8) Remove RF_IOBufHeader and all references to it.
9) Remove desc->cleanupList and all references to it.
Fixes PR#20191


To generate a diff of this commit:
cvs rdiff -r1.16 -r1.16.2.1 src/sys/dev/raidframe/rf_dagutils.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.