1 files changed, 320 insertions, 0 deletions

diff --git a/sys/dev/raidframe/rf_raid5.c b/sys/dev/raidframe/rf_raid5.c
new file mode 100644
index 0000000..c1261ad
--- /dev/null
+++ b/sys/dev/raidframe/rf_raid5.c
@@ -0,0 +1,320 @@
+/*	$FreeBSD$ */
+/*	$NetBSD: rf_raid5.c,v 1.4 2000/01/08 22:57:30 oster Exp $	*/
+/*
+ * Copyright (c) 1995 Carnegie-Mellon University.
+ * All rights reserved.
+ *
+ * Author: Mark Holland
+ *
+ * Permission to use, copy, modify and distribute this software and
+ * its documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
+ * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ */
+
+/******************************************************************************
+ *
+ * rf_raid5.c -- implements RAID Level 5
+ *
+ *****************************************************************************/
+
+#include <dev/raidframe/rf_types.h>
+#include <dev/raidframe/rf_raid.h>
+#include <dev/raidframe/rf_raid5.h>
+#include <dev/raidframe/rf_dag.h>
+#include <dev/raidframe/rf_dagffrd.h>
+#include <dev/raidframe/rf_dagffwr.h>
+#include <dev/raidframe/rf_dagdegrd.h>
+#include <dev/raidframe/rf_dagdegwr.h>
+#include <dev/raidframe/rf_dagutils.h>
+#include <dev/raidframe/rf_general.h>
+#include <dev/raidframe/rf_map.h>
+#include <dev/raidframe/rf_utils.h>
+
+typedef struct RF_Raid5ConfigInfo_s {
+	RF_RowCol_t **stripeIdentifier;	/* filled in at config time and used
+					 * by IdentifyStripe */
+}       RF_Raid5ConfigInfo_t;
+
+int 
+rf_ConfigureRAID5(
+    RF_ShutdownList_t ** listp,
+    RF_Raid_t * raidPtr,
+    RF_Config_t * cfgPtr)
+{
+	RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
+	RF_Raid5ConfigInfo_t *info;
+	RF_RowCol_t i, j, startdisk;
+
+	/* create a RAID level 5 configuration structure */
+	RF_MallocAndAdd(info, sizeof(RF_Raid5ConfigInfo_t), (RF_Raid5ConfigInfo_t *), raidPtr->cleanupList);
+	if (info == NULL)
+		return (ENOMEM);
+	layoutPtr->layoutSpecificInfo = (void *) info;
+
+	RF_ASSERT(raidPtr->numRow == 1);
+
+	/* the stripe identifier must identify the disks in each stripe, IN
+	 * THE ORDER THAT THEY APPEAR IN THE STRIPE. */
+	info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, raidPtr->numCol, raidPtr->cleanupList);
+	if (info->stripeIdentifier == NULL)
+		return (ENOMEM);
+	startdisk = 0;
+	for (i = 0; i < raidPtr->numCol; i++) {
+		for (j = 0; j < raidPtr->numCol; j++) {
+			info->stripeIdentifier[i][j] = (startdisk + j) % raidPtr->numCol;
+		}
+		if ((--startdisk) < 0)
+			startdisk = raidPtr->numCol - 1;
+	}
+
+	/* fill in the remaining layout parameters */
+	layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
+	layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
+	layoutPtr->numDataCol = raidPtr->numCol - 1;
+	layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
+	layoutPtr->numParityCol = 1;
+	layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
+
+	raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
+
+	return (0);
+}
+
+int 
+rf_GetDefaultNumFloatingReconBuffersRAID5(RF_Raid_t * raidPtr)
+{
+	return (20);
+}
+
+RF_HeadSepLimit_t 
+rf_GetDefaultHeadSepLimitRAID5(RF_Raid_t * raidPtr)
+{
+	return (10);
+}
+#if !defined(__NetBSD__) && !defined(__FreeBSD__) && !defined(_KERNEL)
+/* not currently used */
+int 
+rf_ShutdownRAID5(RF_Raid_t * raidPtr)
+{
+	return (0);
+}
+#endif
+
+void 
+rf_MapSectorRAID5(
+    RF_Raid_t * raidPtr,
+    RF_RaidAddr_t raidSector,
+    RF_RowCol_t * row,
+    RF_RowCol_t * col,
+    RF_SectorNum_t * diskSector,
+    int remap)
+{
+	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
+	*row = 0;
+	*col = (SUID % raidPtr->numCol);
+	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
+	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
+}
+
+void 
+rf_MapParityRAID5(
+    RF_Raid_t * raidPtr,
+    RF_RaidAddr_t raidSector,
+    RF_RowCol_t * row,
+    RF_RowCol_t * col,
+    RF_SectorNum_t * diskSector,
+    int remap)
+{
+	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
+
+	*row = 0;
+	*col = raidPtr->Layout.numDataCol - (SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
+	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
+	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
+}
+
+void 
+rf_IdentifyStripeRAID5(
+    RF_Raid_t * raidPtr,
+    RF_RaidAddr_t addr,
+    RF_RowCol_t ** diskids,
+    RF_RowCol_t * outRow)
+{
+	RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
+	RF_Raid5ConfigInfo_t *info = (RF_Raid5ConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
+
+	*outRow = 0;
+	*diskids = info->stripeIdentifier[stripeID % raidPtr->numCol];
+}
+
+void 
+rf_MapSIDToPSIDRAID5(
+    RF_RaidLayout_t * layoutPtr,
+    RF_StripeNum_t stripeID,
+    RF_StripeNum_t * psID,
+    RF_ReconUnitNum_t * which_ru)
+{
+	*which_ru = 0;
+	*psID = stripeID;
+}
+/* select an algorithm for performing an access.  Returns two pointers,
+ * one to a function that will return information about the DAG, and
+ * another to a function that will create the dag.
+ */
+void 
+rf_RaidFiveDagSelect(
+    RF_Raid_t * raidPtr,
+    RF_IoType_t type,
+    RF_AccessStripeMap_t * asmap,
+    RF_VoidFuncPtr * createFunc)
+{
+	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
+	RF_PhysDiskAddr_t *failedPDA = NULL;
+	RF_RowCol_t frow, fcol;
+	RF_RowStatus_t rstat;
+	int     prior_recon;
+
+	RF_ASSERT(RF_IO_IS_R_OR_W(type));
+
+	if (asmap->numDataFailed + asmap->numParityFailed > 1) {
+		RF_ERRORMSG("Multiple disks failed in a single group!  Aborting I/O operation.\n");
+		 /* *infoFunc = */ *createFunc = NULL;
+		return;
+	} else
+		if (asmap->numDataFailed + asmap->numParityFailed == 1) {
+
+			/* if under recon & already reconstructed, redirect
+			 * the access to the spare drive and eliminate the
+			 * failure indication */
+			failedPDA = asmap->failedPDAs[0];
+			frow = failedPDA->row;
+			fcol = failedPDA->col;
+			rstat = raidPtr->status[failedPDA->row];
+			prior_recon = (rstat == rf_rs_reconfigured) || (
+			    (rstat == rf_rs_reconstructing) ?
+			    rf_CheckRUReconstructed(raidPtr->reconControl[frow]->reconMap, failedPDA->startSector) : 0
+			    );
+			if (prior_recon) {
+				RF_RowCol_t or = failedPDA->row, oc = failedPDA->col;
+				RF_SectorNum_t oo = failedPDA->startSector;
+
+				if (layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) {	/* redirect to dist
+											 * spare space */
+
+					if (failedPDA == asmap->parityInfo) {
+
+						/* parity has failed */
+						(layoutPtr->map->MapParity) (raidPtr, failedPDA->raidAddress, &failedPDA->row,
+						    &failedPDA->col, &failedPDA->startSector, RF_REMAP);
+
+						if (asmap->parityInfo->next) {	/* redir 2nd component,
+										 * if any */
+							RF_PhysDiskAddr_t *p = asmap->parityInfo->next;
+							RF_SectorNum_t SUoffs = p->startSector % layoutPtr->sectorsPerStripeUnit;
+							p->row = failedPDA->row;
+							p->col = failedPDA->col;
+							p->startSector = rf_RaidAddressOfPrevStripeUnitBoundary(layoutPtr, failedPDA->startSector) +
+							    SUoffs;	/* cheating:
+									 * startSector is not
+									 * really a RAID address */
+						}
+					} else
+						if (asmap->parityInfo->next && failedPDA == asmap->parityInfo->next) {
+							RF_ASSERT(0);	/* should not ever
+									 * happen */
+						} else {
+
+							/* data has failed */
+							(layoutPtr->map->MapSector) (raidPtr, failedPDA->raidAddress, &failedPDA->row,
+							    &failedPDA->col, &failedPDA->startSector, RF_REMAP);
+
+						}
+
+				} else {	/* redirect to dedicated spare
+						 * space */
+
+					failedPDA->row = raidPtr->Disks[frow][fcol].spareRow;
+					failedPDA->col = raidPtr->Disks[frow][fcol].spareCol;
+
+					/* the parity may have two distinct
+					 * components, both of which may need
+					 * to be redirected */
+					if (asmap->parityInfo->next) {
+						if (failedPDA == asmap->parityInfo) {
+							failedPDA->next->row = failedPDA->row;
+							failedPDA->next->col = failedPDA->col;
+						} else
+							if (failedPDA == asmap->parityInfo->next) {	/* paranoid:  should
+													 * never occur */
+								asmap->parityInfo->row = failedPDA->row;
+								asmap->parityInfo->col = failedPDA->col;
+							}
+					}
+				}
+
+				RF_ASSERT(failedPDA->col != -1);
+
+				if (rf_dagDebug || rf_mapDebug) {
+					printf("raid%d: Redirected type '%c' r %d c %d o %ld -> r %d c %d o %ld\n",
+					       raidPtr->raidid, type, or, oc, 
+					       (long) oo, failedPDA->row, 
+					       failedPDA->col,
+					       (long) failedPDA->startSector);
+				}
+				asmap->numDataFailed = asmap->numParityFailed = 0;
+			}
+		}
+	/* all dags begin/end with block/unblock node therefore, hdrSucc &
+	 * termAnt counts should always be 1 also, these counts should not be
+	 * visible outside dag creation routines - manipulating the counts
+	 * here should be removed */
+	if (type == RF_IO_TYPE_READ) {
+		if (asmap->numDataFailed == 0)
+			*createFunc = (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG;
+		else
+			*createFunc = (RF_VoidFuncPtr) rf_CreateRaidFiveDegradedReadDAG;
+	} else {
+
+
+		/* if mirroring, always use large writes.  If the access
+		 * requires two distinct parity updates, always do a small
+		 * write.  If the stripe contains a failure but the access
+		 * does not, do a small write. The first conditional
+		 * (numStripeUnitsAccessed <= numDataCol/2) uses a
+		 * less-than-or-equal rather than just a less-than because
+		 * when G is 3 or 4, numDataCol/2 is 1, and I want
+		 * single-stripe-unit updates to use just one disk. */
+		if ((asmap->numDataFailed + asmap->numParityFailed) == 0) {
+			if (rf_suppressLocksAndLargeWrites ||
+			    (((asmap->numStripeUnitsAccessed <= (layoutPtr->numDataCol / 2)) && (layoutPtr->numDataCol != 1)) ||
+				(asmap->parityInfo->next != NULL) || rf_CheckStripeForFailures(raidPtr, asmap))) {
+				*createFunc = (RF_VoidFuncPtr) rf_CreateSmallWriteDAG;
+			} else
+				*createFunc = (RF_VoidFuncPtr) rf_CreateLargeWriteDAG;
+		} else {
+			if (asmap->numParityFailed == 1)
+				*createFunc = (RF_VoidFuncPtr) rf_CreateNonRedundantWriteDAG;
+			else
+				if (asmap->numStripeUnitsAccessed != 1 && failedPDA->numSector != layoutPtr->sectorsPerStripeUnit)
+					*createFunc = NULL;
+				else
+					*createFunc = (RF_VoidFuncPtr) rf_CreateDegradedWriteDAG;
+		}
+	}
+}