Annotation of sys/dev/raidframe/rf_dagdegwr.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: rf_dagdegwr.c,v 1.6 2006/07/09 22:10:05 mk Exp $ */
2: /* $NetBSD: rf_dagdegwr.c,v 1.5 2000/01/07 03:40:57 oster Exp $ */
3:
4: /*
5: * Copyright (c) 1995 Carnegie-Mellon University.
6: * All rights reserved.
7: *
8: * Author: Mark Holland, Daniel Stodolsky, William V. Courtright II
9: *
10: * Permission to use, copy, modify and distribute this software and
11: * its documentation is hereby granted, provided that both the copyright
12: * notice and this permission notice appear in all copies of the
13: * software, derivative works or modified versions, and any portions
14: * thereof, and that both notices appear in supporting documentation.
15: *
16: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
18: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19: *
20: * Carnegie Mellon requests users of this software to return to
21: *
22: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
23: * School of Computer Science
24: * Carnegie Mellon University
25: * Pittsburgh PA 15213-3890
26: *
27: * any improvements or extensions that they make and grant Carnegie the
28: * rights to redistribute these changes.
29: */
30:
31: /*
32: * rf_dagdegwr.c
33: *
34: * Code for creating degraded write DAGs.
35: *
36: */
37:
38: #include "rf_types.h"
39: #include "rf_raid.h"
40: #include "rf_dag.h"
41: #include "rf_dagutils.h"
42: #include "rf_dagfuncs.h"
43: #include "rf_debugMem.h"
44: #include "rf_memchunk.h"
45: #include "rf_general.h"
46: #include "rf_dagdegwr.h"
47:
48:
49: /*****************************************************************************
50: *
51: * General comments on DAG creation:
52: *
53: * All DAGs in this file use roll-away error recovery. Each DAG has a single
54: * commit node, usually called "Cmt". If an error occurs before the Cmt node
55: * is reached, the execution engine will halt forward execution and work
56: * backward through the graph, executing the undo functions. Assuming that
57: * each node in the graph prior to the Cmt node are undoable and atomic - or -
58: * does not make changes to permanent state, the graph will fail atomically.
59: * If an error occurs after the Cmt node executes, the engine will roll-forward
60: * through the graph, blindly executing nodes until it reaches the end.
61: * If a graph reaches the end, it is assumed to have completed successfully.
62: *
63: * A graph has only 1 Cmt node.
64: *
65: *****************************************************************************/
66:
67:
68: /*****************************************************************************
69: *
70: * The following wrappers map the standard DAG creation interface to the
71: * DAG creation routines. Additionally, these wrappers enable experimentation
72: * with new DAG structures by providing an extra level of indirection, allowing
73: * the DAG creation routines to be replaced at this single point.
74: *
75: *****************************************************************************/
76:
77: RF_CREATE_DAG_FUNC_DECL(rf_CreateSimpleDegradedWriteDAG)
78: {
79: rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
80: flags, allocList, 1, rf_RecoveryXorFunc, RF_TRUE);
81: }
82:
83: void
84: rf_CreateDegradedWriteDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
85: RF_DagHeader_t *dag_h, void *bp, RF_RaidAccessFlags_t flags,
86: RF_AllocListElem_t *allocList)
87: {
88: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
89: RF_PhysDiskAddr_t *failedPDA = asmap->failedPDAs[0];
90:
91: RF_ASSERT(asmap->numDataFailed == 1);
92: dag_h->creator = "DegradedWriteDAG";
93:
94: /*
95: * If the access writes only a portion of the failed unit, and also
96: * writes some portion of at least one surviving unit, we create two
97: * DAGs, one for the failed component and one for the non-failed
98: * component, and do them sequentially. Note that the fact that we're
99: * accessing only a portion of the failed unit indicates that the
100: * access either starts or ends in the failed unit, and hence we need
101: * create only two dags. This is inefficient in that the same data or
102: * parity can get read and written twice using this structure. I need
103: * to fix this to do the access all at once.
104: */
105: RF_ASSERT(!(asmap->numStripeUnitsAccessed != 1 &&
106: failedPDA->numSector != layoutPtr->sectorsPerStripeUnit));
107: rf_CreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
108: flags, allocList);
109: }
110:
111:
112:
113: /*****************************************************************************
114: *
115: * DAG creation code begins here.
116: *
117: *****************************************************************************/
118:
119:
120: /*****************************************************************************
121: *
122: * CommonCreateSimpleDegradedWriteDAG -- creates a DAG to do a degraded-mode
123: * write, which is as follows
124: *
125: * / {Wnq} --\
126: * hdr -> blockNode -> Rod -> Xor -> Cmt -> Wnp ----> unblock -> term
127: * \ {Rod} / | Wnd ---/
128: * \ {Wnd} -/
129: *
130: * Commit nodes: Xor, Wnd
131: *
132: * IMPORTANT:
133: * This DAG generator does not work for double-degraded archs since it does not
134: * generate Q.
135: *
136: * This dag is essentially identical to the large-write dag, except that the
137: * write to the failed data unit is suppressed.
138: *
139: * IMPORTANT: this dag does not work in the case where the access writes only
140: * a portion of the failed unit, and also writes some portion of at least one
141: * surviving SU. this case is handled in CreateDegradedWriteDAG above.
142: *
143: * The block & unblock nodes are leftovers from a previous version. They
144: * do nothing, but I haven't deleted them because it would be a tremendous
145: * effort to put them back in.
146: *
147: * This dag is used whenever one of the data units in a write has failed.
148: * If it is the parity unit that failed, the nonredundant write dag (below)
149: * is used.
150: *
151: *****************************************************************************/
152:
153: void
154: rf_CommonCreateSimpleDegradedWriteDAG(RF_Raid_t *raidPtr,
155: RF_AccessStripeMap_t *asmap, RF_DagHeader_t *dag_h, void *bp,
156: RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, int nfaults,
157: int (*redFunc) (RF_DagNode_t *), int allowBufferRecycle)
158: {
159: int nNodes, nRrdNodes, nWndNodes, nXorBufs, i, j, paramNum,
160: rdnodesFaked;
161: RF_DagNode_t *blockNode, *unblockNode, *wnpNode, *wnqNode, *termNode;
162: RF_DagNode_t *nodes, *wndNodes, *rrdNodes, *xorNode, *commitNode;
163: RF_SectorCount_t sectorsPerSU;
164: RF_ReconUnitNum_t which_ru;
165: char *xorTargetBuf = NULL; /*
166: * The target buffer for the XOR
167: * operation.
168: */
169: char *overlappingPDAs; /* A temporary array of flags. */
170: RF_AccessStripeMapHeader_t *new_asm_h[2];
171: RF_PhysDiskAddr_t *pda, *parityPDA;
172: RF_StripeNum_t parityStripeID;
173: RF_PhysDiskAddr_t *failedPDA;
174: RF_RaidLayout_t *layoutPtr;
175:
176: layoutPtr = &(raidPtr->Layout);
177: parityStripeID = rf_RaidAddressToParityStripeID(layoutPtr,
178: asmap->raidAddress, &which_ru);
179: sectorsPerSU = layoutPtr->sectorsPerStripeUnit;
180: /*
181: * failedPDA points to the pda within the asm that targets
182: * the failed disk.
183: */
184: failedPDA = asmap->failedPDAs[0];
185:
186: if (rf_dagDebug)
187: printf("[Creating degraded-write DAG]\n");
188:
189: RF_ASSERT(asmap->numDataFailed == 1);
190: dag_h->creator = "SimpleDegradedWriteDAG";
191:
192: /*
193: * Generate two ASMs identifying the surviving data
194: * we need in order to recover the lost data.
195: */
196: /* overlappingPDAs array must be zero'd */
197: RF_Calloc(overlappingPDAs, asmap->numStripeUnitsAccessed,
198: sizeof(char), (char *));
199: rf_GenerateFailedAccessASMs(raidPtr, asmap, failedPDA, dag_h,
200: new_asm_h, &nXorBufs, NULL, overlappingPDAs, allocList);
201:
202: /* Create all the nodes at once. */
203: nWndNodes = asmap->numStripeUnitsAccessed - 1; /*
204: * No access is
205: * generated for the
206: * failed pda.
207: */
208:
209: nRrdNodes = ((new_asm_h[0]) ?
210: new_asm_h[0]->stripeMap->numStripeUnitsAccessed : 0) +
211: ((new_asm_h[1]) ? new_asm_h[1]->stripeMap->numStripeUnitsAccessed
212: : 0);
213: /*
214: * XXX
215: *
216: * There's a bug with a complete stripe overwrite- that means 0 reads
217: * of old data, and the rest of the DAG generation code doesn't like
218: * that. A release is coming, and I don't wanna risk breaking a
219: * critical DAG generator, so here's what I'm gonna do- if there's
220: * no read nodes, I'm gonna fake there being a read node, and I'm
221: * gonna swap in a no-op node in its place (to make all the link-up
222: * code happy).
223: * This should be fixed at some point. --jimz
224: */
225: if (nRrdNodes == 0) {
226: nRrdNodes = 1;
227: rdnodesFaked = 1;
228: } else {
229: rdnodesFaked = 0;
230: }
231: /* Lock, unlock, xor, Wnd, Rrd, W(nfaults). */
232: nNodes = 5 + nfaults + nWndNodes + nRrdNodes;
233: RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t),
234: (RF_DagNode_t *), allocList);
235: i = 0;
236: blockNode = &nodes[i];
237: i += 1;
238: commitNode = &nodes[i];
239: i += 1;
240: unblockNode = &nodes[i];
241: i += 1;
242: termNode = &nodes[i];
243: i += 1;
244: xorNode = &nodes[i];
245: i += 1;
246: wnpNode = &nodes[i];
247: i += 1;
248: wndNodes = &nodes[i];
249: i += nWndNodes;
250: rrdNodes = &nodes[i];
251: i += nRrdNodes;
252: if (nfaults == 2) {
253: wnqNode = &nodes[i];
254: i += 1;
255: } else {
256: wnqNode = NULL;
257: }
258: RF_ASSERT(i == nNodes);
259:
260: /*
261: * This dag can not commit until all rrd and xor Nodes have
262: * completed.
263: */
264: dag_h->numCommitNodes = 1;
265: dag_h->numCommits = 0;
266: dag_h->numSuccedents = 1;
267:
268: RF_ASSERT(nRrdNodes > 0);
269: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
270: rf_NullNodeUndoFunc, NULL, nRrdNodes, 0, 0, 0, dag_h,
271: "Nil", allocList);
272: rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
273: rf_NullNodeUndoFunc, NULL, nWndNodes + nfaults, 1, 0, 0,
274: dag_h, "Cmt", allocList);
275: rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
276: rf_NullNodeUndoFunc, NULL, 1, nWndNodes + nfaults, 0, 0,
277: dag_h, "Nil", allocList);
278: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
279: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
280: rf_InitNode(xorNode, rf_wait, RF_FALSE, redFunc, rf_NullNodeUndoFunc,
281: NULL, 1, nRrdNodes, 2 * nXorBufs + 2, nfaults, dag_h, "Xrc",
282: allocList);
283:
284: /*
285: * Fill in the Rrd nodes. If any of the rrd buffers are the same size
286: * as the failed buffer, save a pointer to it so we can use it as the
287: * target of the XOR. The pdas in the rrd nodes have been range-
288: * restricted, so if a buffer is the same size as the failed buffer,
289: * it must also be at the same alignment within the SU.
290: */
291: i = 0;
292: if (new_asm_h[0]) {
293: for (i = 0, pda = new_asm_h[0]->stripeMap->physInfo;
294: i < new_asm_h[0]->stripeMap->numStripeUnitsAccessed;
295: i++, pda = pda->next) {
296: rf_InitNode(&rrdNodes[i], rf_wait, RF_FALSE,
297: rf_DiskReadFunc, rf_DiskReadUndoFunc,
298: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
299: "Rrd", allocList);
300: RF_ASSERT(pda);
301: rrdNodes[i].params[0].p = pda;
302: rrdNodes[i].params[1].p = pda->bufPtr;
303: rrdNodes[i].params[2].v = parityStripeID;
304: rrdNodes[i].params[3].v = RF_CREATE_PARAM3(
305: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
306: }
307: }
308: /* i now equals the number of stripe units accessed in new_asm_h[0]. */
309: if (new_asm_h[1]) {
310: for (j = 0, pda = new_asm_h[1]->stripeMap->physInfo;
311: j < new_asm_h[1]->stripeMap->numStripeUnitsAccessed;
312: j++, pda = pda->next) {
313: rf_InitNode(&rrdNodes[i + j], rf_wait, RF_FALSE,
314: rf_DiskReadFunc, rf_DiskReadUndoFunc,
315: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
316: "Rrd", allocList);
317: RF_ASSERT(pda);
318: rrdNodes[i + j].params[0].p = pda;
319: rrdNodes[i + j].params[1].p = pda->bufPtr;
320: rrdNodes[i + j].params[2].v = parityStripeID;
321: rrdNodes[i + j].params[3].v = RF_CREATE_PARAM3(
322: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
323: if (allowBufferRecycle &&
324: (pda->numSector == failedPDA->numSector))
325: xorTargetBuf = pda->bufPtr;
326: }
327: }
328: if (rdnodesFaked) {
329: /*
330: * This is where we'll init that fake noop read node.
331: * (XXX should the wakeup func be different ?)
332: */
333: rf_InitNode(&rrdNodes[0], rf_wait, RF_FALSE, rf_NullNodeFunc,
334: rf_NullNodeUndoFunc, NULL, 1, 1, 0, 0, dag_h, "RrN",
335: allocList);
336: }
337: /*
338: * Make a PDA for the parity unit. The parity PDA should start at
339: * the same offset into the SU as the failed PDA.
340: */
341: /*
342: * Danner comment: I don't think this copy is really necessary. We are
343: * in one of two cases here.
344: * (1) The entire failed unit is written. Then asmap->parityInfo will
345: * describe the entire parity.
346: * (2) We are only writing a subset of the failed unit and nothing else.
347: * Then the asmap->parityInfo describes the failed unit and the copy
348: * can also be avoided.
349: */
350:
351: RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t),
352: (RF_PhysDiskAddr_t *), allocList);
353: parityPDA->row = asmap->parityInfo->row;
354: parityPDA->col = asmap->parityInfo->col;
355: parityPDA->startSector = ((asmap->parityInfo->startSector /
356: sectorsPerSU) * sectorsPerSU) + (failedPDA->startSector %
357: sectorsPerSU);
358: parityPDA->numSector = failedPDA->numSector;
359:
360: if (!xorTargetBuf) {
361: RF_CallocAndAdd(xorTargetBuf, 1, rf_RaidAddressToByte(raidPtr,
362: failedPDA->numSector), (char *), allocList);
363: }
364: /* Init the Wnp node. */
365: rf_InitNode(wnpNode, rf_wait, RF_FALSE, rf_DiskWriteFunc,
366: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0,
367: dag_h, "Wnp", allocList);
368: wnpNode->params[0].p = parityPDA;
369: wnpNode->params[1].p = xorTargetBuf;
370: wnpNode->params[2].v = parityStripeID;
371: wnpNode->params[3].v = RF_CREATE_PARAM3(
372: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
373:
374: /* Fill in the Wnq Node. */
375: if (nfaults == 2) {
376: {
377: RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t),
378: (RF_PhysDiskAddr_t *), allocList);
379: parityPDA->row = asmap->qInfo->row;
380: parityPDA->col = asmap->qInfo->col;
381: parityPDA->startSector = ((asmap->qInfo->startSector /
382: sectorsPerSU) * sectorsPerSU) +
383: (failedPDA->startSector % sectorsPerSU);
384: parityPDA->numSector = failedPDA->numSector;
385:
386: rf_InitNode(wnqNode, rf_wait, RF_FALSE,
387: rf_DiskWriteFunc, rf_DiskWriteUndoFunc,
388: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
389: "Wnq", allocList);
390: wnqNode->params[0].p = parityPDA;
391: RF_CallocAndAdd(xorNode->results[1], 1,
392: rf_RaidAddressToByte(raidPtr, failedPDA->numSector),
393: (char *), allocList);
394: wnqNode->params[1].p = xorNode->results[1];
395: wnqNode->params[2].v = parityStripeID;
396: wnqNode->params[3].v = RF_CREATE_PARAM3(
397: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
398: }
399: }
400: /* Fill in the Wnd nodes. */
401: for (pda = asmap->physInfo, i = 0; i < nWndNodes;
402: i++, pda = pda->next) {
403: if (pda == failedPDA) {
404: i--;
405: continue;
406: }
407: rf_InitNode(&wndNodes[i], rf_wait, RF_FALSE, rf_DiskWriteFunc,
408: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0,
409: dag_h, "Wnd", allocList);
410: RF_ASSERT(pda);
411: wndNodes[i].params[0].p = pda;
412: wndNodes[i].params[1].p = pda->bufPtr;
413: wndNodes[i].params[2].v = parityStripeID;
414: wndNodes[i].params[3].v = RF_CREATE_PARAM3(
415: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
416: }
417:
418: /* Fill in the results of the xor node. */
419: xorNode->results[0] = xorTargetBuf;
420:
421: /* Fill in the params of the xor node. */
422:
423: paramNum = 0;
424: if (rdnodesFaked == 0) {
425: for (i = 0; i < nRrdNodes; i++) {
426: /* All the Rrd nodes need to be xored together. */
427: xorNode->params[paramNum++] = rrdNodes[i].params[0];
428: xorNode->params[paramNum++] = rrdNodes[i].params[1];
429: }
430: }
431: for (i = 0; i < nWndNodes; i++) {
432: /*
433: * Any Wnd nodes that overlap the failed access need to be
434: * xored in.
435: */
436: if (overlappingPDAs[i]) {
437: RF_MallocAndAdd(pda, sizeof(RF_PhysDiskAddr_t),
438: (RF_PhysDiskAddr_t *), allocList);
439: bcopy((char *) wndNodes[i].params[0].p, (char *) pda,
440: sizeof(RF_PhysDiskAddr_t));
441: rf_RangeRestrictPDA(raidPtr, failedPDA, pda,
442: RF_RESTRICT_DOBUFFER, 0);
443: xorNode->params[paramNum++].p = pda;
444: xorNode->params[paramNum++].p = pda->bufPtr;
445: }
446: }
447: RF_Free(overlappingPDAs, asmap->numStripeUnitsAccessed * sizeof(char));
448:
449: /*
450: * Install the failed PDA into the xor param list so that the
451: * new data gets xor'd in.
452: */
453: xorNode->params[paramNum++].p = failedPDA;
454: xorNode->params[paramNum++].p = failedPDA->bufPtr;
455:
456: /*
457: * The last 2 params to the recovery xor node are always the failed
458: * PDA and the raidPtr. Install the failedPDA even though we have just
459: * done so above. This allows us to use the same XOR function for both
460: * degraded reads and degraded writes.
461: */
462: xorNode->params[paramNum++].p = failedPDA;
463: xorNode->params[paramNum++].p = raidPtr;
464: RF_ASSERT(paramNum == 2 * nXorBufs + 2);
465:
466: /*
467: * Code to link nodes begins here.
468: */
469:
470: /* Link header to block node. */
471: RF_ASSERT(blockNode->numAntecedents == 0);
472: dag_h->succedents[0] = blockNode;
473:
474: /* Link block node to rd nodes. */
475: RF_ASSERT(blockNode->numSuccedents == nRrdNodes);
476: for (i = 0; i < nRrdNodes; i++) {
477: RF_ASSERT(rrdNodes[i].numAntecedents == 1);
478: blockNode->succedents[i] = &rrdNodes[i];
479: rrdNodes[i].antecedents[0] = blockNode;
480: rrdNodes[i].antType[0] = rf_control;
481: }
482:
483: /* Link read nodes to xor node. */
484: RF_ASSERT(xorNode->numAntecedents == nRrdNodes);
485: for (i = 0; i < nRrdNodes; i++) {
486: RF_ASSERT(rrdNodes[i].numSuccedents == 1);
487: rrdNodes[i].succedents[0] = xorNode;
488: xorNode->antecedents[i] = &rrdNodes[i];
489: xorNode->antType[i] = rf_trueData;
490: }
491:
492: /* Link xor node to commit node. */
493: RF_ASSERT(xorNode->numSuccedents == 1);
494: RF_ASSERT(commitNode->numAntecedents == 1);
495: xorNode->succedents[0] = commitNode;
496: commitNode->antecedents[0] = xorNode;
497: commitNode->antType[0] = rf_control;
498:
499: /* Link commit node to wnd nodes. */
500: RF_ASSERT(commitNode->numSuccedents == nfaults + nWndNodes);
501: for (i = 0; i < nWndNodes; i++) {
502: RF_ASSERT(wndNodes[i].numAntecedents == 1);
503: commitNode->succedents[i] = &wndNodes[i];
504: wndNodes[i].antecedents[0] = commitNode;
505: wndNodes[i].antType[0] = rf_control;
506: }
507:
508: /* Link the commit node to wnp, wnq nodes. */
509: RF_ASSERT(wnpNode->numAntecedents == 1);
510: commitNode->succedents[nWndNodes] = wnpNode;
511: wnpNode->antecedents[0] = commitNode;
512: wnpNode->antType[0] = rf_control;
513: if (nfaults == 2) {
514: RF_ASSERT(wnqNode->numAntecedents == 1);
515: commitNode->succedents[nWndNodes + 1] = wnqNode;
516: wnqNode->antecedents[0] = commitNode;
517: wnqNode->antType[0] = rf_control;
518: }
519: /* Link write new data nodes to unblock node. */
520: RF_ASSERT(unblockNode->numAntecedents == (nWndNodes + nfaults));
521: for (i = 0; i < nWndNodes; i++) {
522: RF_ASSERT(wndNodes[i].numSuccedents == 1);
523: wndNodes[i].succedents[0] = unblockNode;
524: unblockNode->antecedents[i] = &wndNodes[i];
525: unblockNode->antType[i] = rf_control;
526: }
527:
528: /* Link write new parity node to unblock node. */
529: RF_ASSERT(wnpNode->numSuccedents == 1);
530: wnpNode->succedents[0] = unblockNode;
531: unblockNode->antecedents[nWndNodes] = wnpNode;
532: unblockNode->antType[nWndNodes] = rf_control;
533:
534: /* Link write new q node to unblock node. */
535: if (nfaults == 2) {
536: RF_ASSERT(wnqNode->numSuccedents == 1);
537: wnqNode->succedents[0] = unblockNode;
538: unblockNode->antecedents[nWndNodes + 1] = wnqNode;
539: unblockNode->antType[nWndNodes + 1] = rf_control;
540: }
541: /* Link unblock node to term node. */
542: RF_ASSERT(unblockNode->numSuccedents == 1);
543: RF_ASSERT(termNode->numAntecedents == 1);
544: RF_ASSERT(termNode->numSuccedents == 0);
545: unblockNode->succedents[0] = termNode;
546: termNode->antecedents[0] = unblockNode;
547: termNode->antType[0] = rf_control;
548: }
549:
550: #define CONS_PDA(if,start,num) do { \
551: pda_p->row = asmap->if->row; \
552: pda_p->col = asmap->if->col; \
553: pda_p->startSector = ((asmap->if->startSector / secPerSU) * \
554: secPerSU) + start; \
555: pda_p->numSector = num; \
556: pda_p->next = NULL; \
557: RF_MallocAndAdd(pda_p->bufPtr, \
558: rf_RaidAddressToByte(raidPtr,num),(char *), allocList); \
559: } while (0)
560:
561: void
562: rf_WriteGenerateFailedAccessASMs(RF_Raid_t *raidPtr,
563: RF_AccessStripeMap_t *asmap, RF_PhysDiskAddr_t **pdap, int *nNodep,
564: RF_PhysDiskAddr_t **pqpdap, int *nPQNodep, RF_AllocListElem_t *allocList)
565: {
566: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
567: int PDAPerDisk, i;
568: RF_SectorCount_t secPerSU = layoutPtr->sectorsPerStripeUnit;
569: int numDataCol = layoutPtr->numDataCol;
570: int state;
571: unsigned napdas;
572: RF_SectorNum_t fone_start, fone_end, ftwo_start = 0, ftwo_end;
573: RF_PhysDiskAddr_t *fone = asmap->failedPDAs[0];
574: RF_PhysDiskAddr_t *ftwo = asmap->failedPDAs[1];
575: RF_PhysDiskAddr_t *pda_p;
576: RF_RaidAddr_t sosAddr;
577:
578: /*
579: * Determine how many pda's we will have to generate per unaccessed
580: * stripe. If there is only one failed data unit, it is one; if two,
581: * possibly two, depending whether they overlap.
582: */
583:
584: fone_start = rf_StripeUnitOffset(layoutPtr, fone->startSector);
585: fone_end = fone_start + fone->numSector;
586:
587: if (asmap->numDataFailed == 1) {
588: PDAPerDisk = 1;
589: state = 1;
590: RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t),
591: (RF_PhysDiskAddr_t *), allocList);
592: pda_p = *pqpdap;
593: /* Build p. */
594: CONS_PDA(parityInfo, fone_start, fone->numSector);
595: pda_p->type = RF_PDA_TYPE_PARITY;
596: pda_p++;
597: /* Build q. */
598: CONS_PDA(qInfo, fone_start, fone->numSector);
599: pda_p->type = RF_PDA_TYPE_Q;
600: } else {
601: ftwo_start = rf_StripeUnitOffset(layoutPtr, ftwo->startSector);
602: ftwo_end = ftwo_start + ftwo->numSector;
603: if (fone->numSector + ftwo->numSector > secPerSU) {
604: PDAPerDisk = 1;
605: state = 2;
606: RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t),
607: (RF_PhysDiskAddr_t *), allocList);
608: pda_p = *pqpdap;
609: CONS_PDA(parityInfo, 0, secPerSU);
610: pda_p->type = RF_PDA_TYPE_PARITY;
611: pda_p++;
612: CONS_PDA(qInfo, 0, secPerSU);
613: pda_p->type = RF_PDA_TYPE_Q;
614: } else {
615: PDAPerDisk = 2;
616: state = 3;
617: /* Four of them, fone, then ftwo. */
618: RF_MallocAndAdd(*pqpdap, 4 * sizeof(RF_PhysDiskAddr_t),
619: (RF_PhysDiskAddr_t *), allocList);
620: pda_p = *pqpdap;
621: CONS_PDA(parityInfo, fone_start, fone->numSector);
622: pda_p->type = RF_PDA_TYPE_PARITY;
623: pda_p++;
624: CONS_PDA(qInfo, fone_start, fone->numSector);
625: pda_p->type = RF_PDA_TYPE_Q;
626: pda_p++;
627: CONS_PDA(parityInfo, ftwo_start, ftwo->numSector);
628: pda_p->type = RF_PDA_TYPE_PARITY;
629: pda_p++;
630: CONS_PDA(qInfo, ftwo_start, ftwo->numSector);
631: pda_p->type = RF_PDA_TYPE_Q;
632: }
633: }
634: /* Figure out number of nonaccessed pda. */
635: napdas = PDAPerDisk * (numDataCol - 2);
636: *nPQNodep = PDAPerDisk;
637:
638: *nNodep = napdas;
639: if (napdas == 0)
640: return; /* Short circuit. */
641:
642: /* Allocate up our list of pda's. */
643:
644: RF_CallocAndAdd(pda_p, napdas, sizeof(RF_PhysDiskAddr_t),
645: (RF_PhysDiskAddr_t *), allocList);
646: *pdap = pda_p;
647:
648: /* Link them together. */
649: for (i = 0; i < (napdas - 1); i++)
650: pda_p[i].next = pda_p + (i + 1);
651:
652: sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr,
653: asmap->raidAddress);
654: for (i = 0; i < numDataCol; i++) {
655: if ((pda_p - (*pdap)) == napdas)
656: continue;
657: pda_p->type = RF_PDA_TYPE_DATA;
658: pda_p->raidAddress = sosAddr + (i * secPerSU);
659: (raidPtr->Layout.map->MapSector) (raidPtr, pda_p->raidAddress,
660: &(pda_p->row), &(pda_p->col), &(pda_p->startSector), 0);
661: /* Skip over dead disks. */
662: if (RF_DEAD_DISK(raidPtr->Disks[pda_p->row][pda_p->col].status))
663: continue;
664: switch (state) {
665: case 1: /* Fone. */
666: pda_p->numSector = fone->numSector;
667: pda_p->raidAddress += fone_start;
668: pda_p->startSector += fone_start;
669: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
670: raidPtr, pda_p->numSector), (char *), allocList);
671: break;
672: case 2: /* Full stripe. */
673: pda_p->numSector = secPerSU;
674: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
675: raidPtr, secPerSU), (char *), allocList);
676: break;
677: case 3: /* Two slabs. */
678: pda_p->numSector = fone->numSector;
679: pda_p->raidAddress += fone_start;
680: pda_p->startSector += fone_start;
681: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
682: raidPtr, pda_p->numSector), (char *), allocList);
683: pda_p++;
684: pda_p->type = RF_PDA_TYPE_DATA;
685: pda_p->raidAddress = sosAddr + (i * secPerSU);
686: (raidPtr->Layout.map->MapSector) (raidPtr,
687: pda_p->raidAddress, &(pda_p->row), &(pda_p->col),
688: &(pda_p->startSector), 0);
689: pda_p->numSector = ftwo->numSector;
690: pda_p->raidAddress += ftwo_start;
691: pda_p->startSector += ftwo_start;
692: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
693: raidPtr, pda_p->numSector), (char *), allocList);
694: break;
695: default:
696: RF_PANIC();
697: }
698: pda_p++;
699: }
700:
701: RF_ASSERT(pda_p - *pdap == napdas);
702: return;
703: }
704:
705: #define DISK_NODE_PDA(node) ((node)->params[0].p)
706:
707: #define DISK_NODE_PARAMS(_node_,_p_) do { \
708: (_node_).params[0].p = _p_ ; \
709: (_node_).params[1].p = (_p_)->bufPtr; \
710: (_node_).params[2].v = parityStripeID; \
711: (_node_).params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, \
712: 0, 0, which_ru); \
713: } while (0)
714:
715: void
716: rf_DoubleDegSmallWrite(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
717: RF_DagHeader_t *dag_h, void *bp, RF_RaidAccessFlags_t flags,
718: RF_AllocListElem_t *allocList, char *redundantReadNodeName,
719: char *redundantWriteNodeName, char *recoveryNodeName,
720: int (*recovFunc) (RF_DagNode_t *))
721: {
722: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
723: RF_DagNode_t *nodes, *wudNodes, *rrdNodes, *recoveryNode, *blockNode,
724: *unblockNode, *rpNodes, *rqNodes, *wpNodes, *wqNodes, *termNode;
725: RF_PhysDiskAddr_t *pda, *pqPDAs;
726: RF_PhysDiskAddr_t *npdas;
727: int nWriteNodes, nNodes, nReadNodes, nRrdNodes, nWudNodes, i;
728: RF_ReconUnitNum_t which_ru;
729: int nPQNodes;
730: RF_StripeNum_t parityStripeID = rf_RaidAddressToParityStripeID(
731: layoutPtr, asmap->raidAddress, &which_ru);
732:
733: /*
734: * Simple small write case - First part looks like a reconstruct-read
735: * of the failed data units. Then a write of all data units not
736: * failed.
737: */
738:
739:
740: /*
741: * Hdr | ------Block- / / \ Rrd Rrd ... Rrd Rp Rq \ \
742: * / -------PQ----- / \ \ Wud Wp WQ \ | /
743: * --Unblock- | T
744: *
745: * Rrd = read recovery data (potentially none)
746: * Wud = write user data (not incl. failed disks)
747: * Wp = Write P (could be two)
748: * Wq = Write Q (could be two)
749: *
750: */
751:
752: rf_WriteGenerateFailedAccessASMs(raidPtr, asmap, &npdas, &nRrdNodes,
753: &pqPDAs, &nPQNodes, allocList);
754:
755: RF_ASSERT(asmap->numDataFailed == 1);
756:
757: nWudNodes = asmap->numStripeUnitsAccessed - (asmap->numDataFailed);
758: nReadNodes = nRrdNodes + 2 * nPQNodes;
759: nWriteNodes = nWudNodes + 2 * nPQNodes;
760: nNodes = 4 + nReadNodes + nWriteNodes;
761:
762: RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *),
763: allocList);
764: blockNode = nodes;
765: unblockNode = blockNode + 1;
766: termNode = unblockNode + 1;
767: recoveryNode = termNode + 1;
768: rrdNodes = recoveryNode + 1;
769: rpNodes = rrdNodes + nRrdNodes;
770: rqNodes = rpNodes + nPQNodes;
771: wudNodes = rqNodes + nPQNodes;
772: wpNodes = wudNodes + nWudNodes;
773: wqNodes = wpNodes + nPQNodes;
774:
775: dag_h->creator = "PQ_DDSimpleSmallWrite";
776: dag_h->numSuccedents = 1;
777: dag_h->succedents[0] = blockNode;
778: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
779: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
780: termNode->antecedents[0] = unblockNode;
781: termNode->antType[0] = rf_control;
782:
783: /* Init the block and unblock nodes. */
784: /* The block node has all the read nodes as successors. */
785: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
786: rf_NullNodeUndoFunc, NULL, nReadNodes, 0, 0, 0, dag_h,
787: "Nil", allocList);
788: for (i = 0; i < nReadNodes; i++)
789: blockNode->succedents[i] = rrdNodes + i;
790:
791: /* The unblock node has all the writes as successors. */
792: rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
793: rf_NullNodeUndoFunc, NULL, 1, nWriteNodes, 0, 0, dag_h,
794: "Nil", allocList);
795: for (i = 0; i < nWriteNodes; i++) {
796: unblockNode->antecedents[i] = wudNodes + i;
797: unblockNode->antType[i] = rf_control;
798: }
799: unblockNode->succedents[0] = termNode;
800:
801: #define INIT_READ_NODE(node,name) do { \
802: rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskReadFunc, \
803: rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, \
804: dag_h, name, allocList); \
805: (node)->succedents[0] = recoveryNode; \
806: (node)->antecedents[0] = blockNode; \
807: (node)->antType[0] = rf_control; \
808: } while (0)
809:
810: /* Build the read nodes. */
811: pda = npdas;
812: for (i = 0; i < nRrdNodes; i++, pda = pda->next) {
813: INIT_READ_NODE(rrdNodes + i, "rrd");
814: DISK_NODE_PARAMS(rrdNodes[i], pda);
815: }
816:
817: /* Read redundancy pdas. */
818: pda = pqPDAs;
819: INIT_READ_NODE(rpNodes, "Rp");
820: RF_ASSERT(pda);
821: DISK_NODE_PARAMS(rpNodes[0], pda);
822: pda++;
823: INIT_READ_NODE(rqNodes, redundantReadNodeName);
824: RF_ASSERT(pda);
825: DISK_NODE_PARAMS(rqNodes[0], pda);
826: if (nPQNodes == 2) {
827: pda++;
828: INIT_READ_NODE(rpNodes + 1, "Rp");
829: RF_ASSERT(pda);
830: DISK_NODE_PARAMS(rpNodes[1], pda);
831: pda++;
832: INIT_READ_NODE(rqNodes + 1, redundantReadNodeName);
833: RF_ASSERT(pda);
834: DISK_NODE_PARAMS(rqNodes[1], pda);
835: }
836: /*
837: * The recovery node has all reads as precedessors and all writes as
838: * successors. It generates a result for every write P or write Q
839: * node. As parameters, it takes a pda per read and a pda per stripe
840: * of user data written. It also takes as the last params the raidPtr
841: * and asm. For results, it takes PDA for P & Q.
842: */
843:
844: rf_InitNode(recoveryNode, rf_wait, RF_FALSE, recovFunc,
845: rf_NullNodeUndoFunc, NULL,
846: nWriteNodes, /* succesors */
847: nReadNodes, /* preds */
848: nReadNodes + nWudNodes + 3, /* params */
849: 2 * nPQNodes, /* results */
850: dag_h, recoveryNodeName, allocList);
851:
852:
853:
854: for (i = 0; i < nReadNodes; i++) {
855: recoveryNode->antecedents[i] = rrdNodes + i;
856: recoveryNode->antType[i] = rf_control;
857: recoveryNode->params[i].p = DISK_NODE_PDA(rrdNodes + i);
858: }
859: for (i = 0; i < nWudNodes; i++) {
860: recoveryNode->succedents[i] = wudNodes + i;
861: }
862: recoveryNode->params[nReadNodes + nWudNodes].p = asmap->failedPDAs[0];
863: recoveryNode->params[nReadNodes + nWudNodes + 1].p = raidPtr;
864: recoveryNode->params[nReadNodes + nWudNodes + 2].p = asmap;
865:
866: for (; i < nWriteNodes; i++)
867: recoveryNode->succedents[i] = wudNodes + i;
868:
869: pda = pqPDAs;
870: recoveryNode->results[0] = pda;
871: pda++;
872: recoveryNode->results[1] = pda;
873: if (nPQNodes == 2) {
874: pda++;
875: recoveryNode->results[2] = pda;
876: pda++;
877: recoveryNode->results[3] = pda;
878: }
879: /* Fill writes. */
880: #define INIT_WRITE_NODE(node,name) do { \
881: rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskWriteFunc, \
882: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, \
883: dag_h, name, allocList); \
884: (node)->succedents[0] = unblockNode; \
885: (node)->antecedents[0] = recoveryNode; \
886: (node)->antType[0] = rf_control; \
887: } while (0)
888:
889: pda = asmap->physInfo;
890: for (i = 0; i < nWudNodes; i++) {
891: INIT_WRITE_NODE(wudNodes + i, "Wd");
892: DISK_NODE_PARAMS(wudNodes[i], pda);
893: recoveryNode->params[nReadNodes + i].p =
894: DISK_NODE_PDA(wudNodes + i);
895: pda = pda->next;
896: }
897: /* Write redundancy pdas. */
898: pda = pqPDAs;
899: INIT_WRITE_NODE(wpNodes, "Wp");
900: RF_ASSERT(pda);
901: DISK_NODE_PARAMS(wpNodes[0], pda);
902: pda++;
903: INIT_WRITE_NODE(wqNodes, "Wq");
904: RF_ASSERT(pda);
905: DISK_NODE_PARAMS(wqNodes[0], pda);
906: if (nPQNodes == 2) {
907: pda++;
908: INIT_WRITE_NODE(wpNodes + 1, "Wp");
909: RF_ASSERT(pda);
910: DISK_NODE_PARAMS(wpNodes[1], pda);
911: pda++;
912: INIT_WRITE_NODE(wqNodes + 1, "Wq");
913: RF_ASSERT(pda);
914: DISK_NODE_PARAMS(wqNodes[1], pda);
915: }
916: }
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