rf_pqdegdags.c revision 1.13 1 1.13 mbalmer /* $NetBSD: rf_pqdegdags.c,v 1.13 2011/08/01 12:28:53 mbalmer Exp $ */
2 1.1 oster /*
3 1.1 oster * Copyright (c) 1995 Carnegie-Mellon University.
4 1.1 oster * All rights reserved.
5 1.1 oster *
6 1.1 oster * Author: Daniel Stodolsky
7 1.1 oster *
8 1.1 oster * Permission to use, copy, modify and distribute this software and
9 1.1 oster * its documentation is hereby granted, provided that both the copyright
10 1.1 oster * notice and this permission notice appear in all copies of the
11 1.1 oster * software, derivative works or modified versions, and any portions
12 1.1 oster * thereof, and that both notices appear in supporting documentation.
13 1.1 oster *
14 1.1 oster * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 1.1 oster * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
16 1.1 oster * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 1.1 oster *
18 1.1 oster * Carnegie Mellon requests users of this software to return to
19 1.1 oster *
20 1.1 oster * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU
21 1.1 oster * School of Computer Science
22 1.1 oster * Carnegie Mellon University
23 1.1 oster * Pittsburgh PA 15213-3890
24 1.1 oster *
25 1.1 oster * any improvements or extensions that they make and grant Carnegie the
26 1.1 oster * rights to redistribute these changes.
27 1.1 oster */
28 1.1 oster
29 1.1 oster /*
30 1.1 oster * rf_pqdegdags.c
31 1.3 oster * Degraded mode dags for double fault cases.
32 1.1 oster */
33 1.1 oster
34 1.8 lukem
35 1.8 lukem #include <sys/cdefs.h>
36 1.13 mbalmer __KERNEL_RCSID(0, "$NetBSD: rf_pqdegdags.c,v 1.13 2011/08/01 12:28:53 mbalmer Exp $");
37 1.1 oster
38 1.1 oster #include "rf_archs.h"
39 1.1 oster
40 1.1 oster #if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
41 1.1 oster
42 1.7 oster #include <dev/raidframe/raidframevar.h>
43 1.7 oster
44 1.1 oster #include "rf_raid.h"
45 1.1 oster #include "rf_dag.h"
46 1.5 oster #include "rf_dagdegrd.h"
47 1.5 oster #include "rf_dagdegwr.h"
48 1.1 oster #include "rf_dagfuncs.h"
49 1.1 oster #include "rf_dagutils.h"
50 1.1 oster #include "rf_etimer.h"
51 1.1 oster #include "rf_acctrace.h"
52 1.1 oster #include "rf_general.h"
53 1.1 oster #include "rf_pqdegdags.h"
54 1.1 oster #include "rf_pq.h"
55 1.1 oster
56 1.10 perry static void
57 1.3 oster applyPDA(RF_Raid_t * raidPtr, RF_PhysDiskAddr_t * pda, RF_PhysDiskAddr_t * ppda,
58 1.3 oster RF_PhysDiskAddr_t * qpda, void *bp);
59 1.1 oster
60 1.1 oster /*
61 1.3 oster Two data drives have failed, and we are doing a read that covers one of them.
62 1.3 oster We may also be reading some of the surviving drives.
63 1.3 oster
64 1.1 oster
65 1.1 oster *****************************************************************************************
66 1.1 oster *
67 1.1 oster * creates a DAG to perform a degraded-mode read of data within one stripe.
68 1.1 oster * This DAG is as follows:
69 1.1 oster *
70 1.1 oster * Hdr
71 1.1 oster * |
72 1.1 oster * Block
73 1.1 oster * / / \ \ \ \
74 1.1 oster * Rud ... Rud Rrd ... Rrd Rp Rq
75 1.1 oster * | \ | \ | \ | \ | \ | \
76 1.1 oster *
77 1.1 oster * | |
78 1.1 oster * Unblock X
79 1.1 oster * \ /
80 1.1 oster * ------ T ------
81 1.1 oster *
82 1.1 oster * Each R node is a successor of the L node
83 1.1 oster * One successor arc from each R node goes to U, and the other to X
84 1.1 oster * There is one Rud for each chunk of surviving user data requested by the user,
85 1.1 oster * and one Rrd for each chunk of surviving user data _not_ being read by the user
86 1.1 oster * R = read, ud = user data, rd = recovery (surviving) data, p = P data, q = Qdata
87 1.1 oster * X = pq recovery node, T = terminate
88 1.1 oster *
89 1.1 oster * The block & unblock nodes are leftovers from a previous version. They
90 1.1 oster * do nothing, but I haven't deleted them because it would be a tremendous
91 1.1 oster * effort to put them back in.
92 1.1 oster *
93 1.1 oster * Note: The target buffer for the XOR node is set to the actual user buffer where the
94 1.1 oster * failed data is supposed to end up. This buffer is zero'd by the code here. Thus,
95 1.1 oster * if you create a degraded read dag, use it, and then re-use, you have to be sure to
96 1.1 oster * zero the target buffer prior to the re-use.
97 1.1 oster *
98 1.1 oster * Every buffer read is passed to the pq recovery node, whose job it is to sort out whats
99 1.1 oster * needs and what's not.
100 1.1 oster ****************************************************************************************/
101 1.1 oster /* init a disk node with 2 successors and one predecessor */
102 1.1 oster #define INIT_DISK_NODE(node,name) \
103 1.1 oster rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 2,1,4,0, dag_h, name, allocList); \
104 1.1 oster (node)->succedents[0] = unblockNode; \
105 1.1 oster (node)->succedents[1] = recoveryNode; \
106 1.1 oster (node)->antecedents[0] = blockNode; \
107 1.1 oster (node)->antType[0] = rf_control
108 1.1 oster
109 1.1 oster #define DISK_NODE_PARAMS(_node_,_p_) \
110 1.1 oster (_node_).params[0].p = _p_ ; \
111 1.1 oster (_node_).params[1].p = (_p_)->bufPtr; \
112 1.1 oster (_node_).params[2].v = parityStripeID; \
113 1.9 oster (_node_).params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, which_ru)
114 1.1 oster
115 1.1 oster #define DISK_NODE_PDA(node) ((node)->params[0].p)
116 1.1 oster
117 1.1 oster RF_CREATE_DAG_FUNC_DECL(rf_PQ_DoubleDegRead)
118 1.1 oster {
119 1.3 oster rf_DoubleDegRead(raidPtr, asmap, dag_h, bp, flags, allocList,
120 1.3 oster "Rq", "PQ Recovery", rf_PQDoubleRecoveryFunc);
121 1.1 oster }
122 1.3 oster
123 1.10 perry static void
124 1.12 dsl applyPDA(RF_Raid_t *raidPtr, RF_PhysDiskAddr_t *pda, RF_PhysDiskAddr_t *ppda, RF_PhysDiskAddr_t *qpda, void *bp)
125 1.1 oster {
126 1.3 oster RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
127 1.3 oster RF_RaidAddr_t s0off = rf_StripeUnitOffset(layoutPtr, ppda->startSector);
128 1.3 oster RF_SectorCount_t s0len = ppda->numSector, len;
129 1.3 oster RF_SectorNum_t suoffset;
130 1.3 oster unsigned coeff;
131 1.3 oster char *pbuf = ppda->bufPtr;
132 1.3 oster char *qbuf = qpda->bufPtr;
133 1.3 oster char *buf;
134 1.3 oster int delta;
135 1.3 oster
136 1.3 oster suoffset = rf_StripeUnitOffset(layoutPtr, pda->startSector);
137 1.3 oster len = pda->numSector;
138 1.3 oster /* see if pda intersects a recovery pda */
139 1.3 oster if ((suoffset < s0off + s0len) && (suoffset + len > s0off)) {
140 1.3 oster buf = pda->bufPtr;
141 1.3 oster coeff = rf_RaidAddressToStripeUnitID(&(raidPtr->Layout), pda->raidAddress);
142 1.3 oster coeff = (coeff % raidPtr->Layout.numDataCol);
143 1.3 oster
144 1.3 oster if (suoffset < s0off) {
145 1.3 oster delta = s0off - suoffset;
146 1.3 oster buf += rf_RaidAddressToStripeUnitID(&(raidPtr->Layout), delta);
147 1.3 oster suoffset = s0off;
148 1.3 oster len -= delta;
149 1.3 oster }
150 1.3 oster if (suoffset > s0off) {
151 1.3 oster delta = suoffset - s0off;
152 1.3 oster pbuf += rf_RaidAddressToStripeUnitID(&(raidPtr->Layout), delta);
153 1.3 oster qbuf += rf_RaidAddressToStripeUnitID(&(raidPtr->Layout), delta);
154 1.3 oster }
155 1.3 oster if ((suoffset + len) > (s0len + s0off))
156 1.3 oster len = s0len + s0off - suoffset;
157 1.3 oster
158 1.3 oster /* src, dest, len */
159 1.3 oster rf_bxor(buf, pbuf, rf_RaidAddressToByte(raidPtr, len), bp);
160 1.3 oster
161 1.3 oster /* dest, src, len, coeff */
162 1.3 oster rf_IncQ((unsigned long *) qbuf, (unsigned long *) buf, rf_RaidAddressToByte(raidPtr, len), coeff);
163 1.1 oster }
164 1.1 oster }
165 1.1 oster /*
166 1.1 oster Recover data in the case of a double failure. There can be two
167 1.1 oster result buffers, one for each chunk of data trying to be recovered.
168 1.1 oster The params are pda's that have not been range restricted or otherwise
169 1.1 oster politely massaged - this should be done here. The last params are the
170 1.1 oster pdas of P and Q, followed by the raidPtr. The list can look like
171 1.1 oster
172 1.1 oster pda, pda, ... , p pda, q pda, raidptr, asm
173 1.3 oster
174 1.1 oster or
175 1.1 oster
176 1.1 oster pda, pda, ... , p_1 pda, p_2 pda, q_1 pda, q_2 pda, raidptr, asm
177 1.1 oster
178 1.13 mbalmer depending on whether two chunks of recovery data were required.
179 1.1 oster
180 1.1 oster The second condition only arises if there are two failed buffers
181 1.1 oster whose lengths do not add up a stripe unit.
182 1.1 oster */
183 1.1 oster
184 1.1 oster
185 1.10 perry int
186 1.12 dsl rf_PQDoubleRecoveryFunc(RF_DagNode_t *node)
187 1.1 oster {
188 1.3 oster int np = node->numParams;
189 1.3 oster RF_AccessStripeMap_t *asmap = (RF_AccessStripeMap_t *) node->params[np - 1].p;
190 1.3 oster RF_Raid_t *raidPtr = (RF_Raid_t *) node->params[np - 2].p;
191 1.3 oster RF_RaidLayout_t *layoutPtr = (RF_RaidLayout_t *) & (raidPtr->Layout);
192 1.3 oster int d, i;
193 1.3 oster unsigned coeff;
194 1.3 oster RF_RaidAddr_t sosAddr, suoffset;
195 1.3 oster RF_SectorCount_t len, secPerSU = layoutPtr->sectorsPerStripeUnit;
196 1.3 oster int two = 0;
197 1.3 oster RF_PhysDiskAddr_t *ppda, *ppda2, *qpda, *qpda2, *pda, npda;
198 1.3 oster char *buf;
199 1.3 oster int numDataCol = layoutPtr->numDataCol;
200 1.3 oster RF_Etimer_t timer;
201 1.3 oster RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
202 1.3 oster
203 1.3 oster RF_ETIMER_START(timer);
204 1.3 oster
205 1.3 oster if (asmap->failedPDAs[1] &&
206 1.3 oster (asmap->failedPDAs[1]->numSector + asmap->failedPDAs[0]->numSector < secPerSU)) {
207 1.3 oster RF_ASSERT(0);
208 1.3 oster ppda = node->params[np - 6].p;
209 1.3 oster ppda2 = node->params[np - 5].p;
210 1.3 oster qpda = node->params[np - 4].p;
211 1.3 oster qpda2 = node->params[np - 3].p;
212 1.3 oster d = (np - 6);
213 1.3 oster two = 1;
214 1.3 oster } else {
215 1.3 oster ppda = node->params[np - 4].p;
216 1.3 oster qpda = node->params[np - 3].p;
217 1.3 oster d = (np - 4);
218 1.3 oster }
219 1.3 oster
220 1.3 oster for (i = 0; i < d; i++) {
221 1.3 oster pda = node->params[i].p;
222 1.3 oster buf = pda->bufPtr;
223 1.3 oster suoffset = rf_StripeUnitOffset(layoutPtr, pda->startSector);
224 1.3 oster len = pda->numSector;
225 1.3 oster coeff = rf_RaidAddressToStripeUnitID(layoutPtr, pda->raidAddress);
226 1.3 oster /* compute the data unit offset within the column */
227 1.3 oster coeff = (coeff % raidPtr->Layout.numDataCol);
228 1.3 oster /* see if pda intersects a recovery pda */
229 1.3 oster applyPDA(raidPtr, pda, ppda, qpda, node->dagHdr->bp);
230 1.3 oster if (two)
231 1.3 oster applyPDA(raidPtr, pda, ppda, qpda, node->dagHdr->bp);
232 1.1 oster }
233 1.3 oster
234 1.3 oster /* ok, we got the parity back to the point where we can recover. We
235 1.3 oster * now need to determine the coeff of the columns that need to be
236 1.3 oster * recovered. We can also only need to recover a single stripe unit. */
237 1.3 oster
238 1.3 oster if (asmap->failedPDAs[1] == NULL) { /* only a single stripe unit
239 1.3 oster * to recover. */
240 1.3 oster pda = asmap->failedPDAs[0];
241 1.3 oster sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, asmap->raidAddress);
242 1.3 oster /* need to determine the column of the other failed disk */
243 1.3 oster coeff = rf_RaidAddressToStripeUnitID(layoutPtr, pda->raidAddress);
244 1.3 oster /* compute the data unit offset within the column */
245 1.3 oster coeff = (coeff % raidPtr->Layout.numDataCol);
246 1.3 oster for (i = 0; i < numDataCol; i++) {
247 1.3 oster npda.raidAddress = sosAddr + (i * secPerSU);
248 1.3 oster (raidPtr->Layout.map->MapSector) (raidPtr, npda.raidAddress, &(npda.row), &(npda.col), &(npda.startSector), 0);
249 1.3 oster /* skip over dead disks */
250 1.3 oster if (RF_DEAD_DISK(raidPtr->Disks[npda.row][npda.col].status))
251 1.3 oster if (i != coeff)
252 1.3 oster break;
253 1.3 oster }
254 1.3 oster RF_ASSERT(i < numDataCol);
255 1.3 oster RF_ASSERT(two == 0);
256 1.3 oster /* recover the data. Since we need only want to recover one
257 1.3 oster * column, we overwrite the parity with the other one. */
258 1.3 oster if (coeff < i) /* recovering 'a' */
259 1.3 oster rf_PQ_recover((unsigned long *) ppda->bufPtr, (unsigned long *) qpda->bufPtr, (unsigned long *) pda->bufPtr, (unsigned long *) ppda->bufPtr, rf_RaidAddressToByte(raidPtr, pda->numSector), coeff, i);
260 1.3 oster else /* recovering 'b' */
261 1.3 oster rf_PQ_recover((unsigned long *) ppda->bufPtr, (unsigned long *) qpda->bufPtr, (unsigned long *) ppda->bufPtr, (unsigned long *) pda->bufPtr, rf_RaidAddressToByte(raidPtr, pda->numSector), i, coeff);
262 1.3 oster } else
263 1.3 oster RF_PANIC();
264 1.3 oster
265 1.3 oster RF_ETIMER_STOP(timer);
266 1.3 oster RF_ETIMER_EVAL(timer);
267 1.3 oster if (tracerec)
268 1.3 oster tracerec->q_us += RF_ETIMER_VAL_US(timer);
269 1.3 oster rf_GenericWakeupFunc(node, 0);
270 1.3 oster return (0);
271 1.1 oster }
272 1.1 oster
273 1.10 perry int
274 1.12 dsl rf_PQWriteDoubleRecoveryFunc(RF_DagNode_t *node)
275 1.1 oster {
276 1.3 oster /* The situation:
277 1.10 perry *
278 1.3 oster * We are doing a write that hits only one failed data unit. The other
279 1.3 oster * failed data unit is not being overwritten, so we need to generate
280 1.3 oster * it.
281 1.10 perry *
282 1.3 oster * For the moment, we assume all the nonfailed data being written is in
283 1.3 oster * the shadow of the failed data unit. (i.e,, either a single data
284 1.3 oster * unit write or the entire failed stripe unit is being overwritten. )
285 1.10 perry *
286 1.3 oster * Recovery strategy: apply the recovery data to the parity and q. Use P
287 1.3 oster * & Q to recover the second failed data unit in P. Zero fill Q, then
288 1.3 oster * apply the recovered data to p. Then apply the data being written to
289 1.3 oster * the failed drive. Then walk through the surviving drives, applying
290 1.3 oster * new data when it exists, othewise the recovery data. Quite a mess.
291 1.10 perry *
292 1.10 perry *
293 1.3 oster * The params
294 1.10 perry *
295 1.3 oster * read pda0, read pda1, ... read pda (numDataCol-3), write pda0, ... ,
296 1.3 oster * write pda (numStripeUnitAccess - numDataFailed), failed pda,
297 1.3 oster * raidPtr, asmap */
298 1.3 oster
299 1.3 oster int np = node->numParams;
300 1.3 oster RF_AccessStripeMap_t *asmap = (RF_AccessStripeMap_t *) node->params[np - 1].p;
301 1.3 oster RF_Raid_t *raidPtr = (RF_Raid_t *) node->params[np - 2].p;
302 1.3 oster RF_RaidLayout_t *layoutPtr = (RF_RaidLayout_t *) & (raidPtr->Layout);
303 1.3 oster int i;
304 1.3 oster RF_RaidAddr_t sosAddr;
305 1.3 oster unsigned coeff;
306 1.3 oster RF_StripeCount_t secPerSU = layoutPtr->sectorsPerStripeUnit;
307 1.3 oster RF_PhysDiskAddr_t *ppda, *qpda, *pda, npda;
308 1.3 oster int numDataCol = layoutPtr->numDataCol;
309 1.3 oster RF_Etimer_t timer;
310 1.3 oster RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
311 1.3 oster
312 1.3 oster RF_ASSERT(node->numResults == 2);
313 1.3 oster RF_ASSERT(asmap->failedPDAs[1] == NULL);
314 1.3 oster RF_ETIMER_START(timer);
315 1.3 oster ppda = node->results[0];
316 1.3 oster qpda = node->results[1];
317 1.3 oster /* apply the recovery data */
318 1.3 oster for (i = 0; i < numDataCol - 2; i++)
319 1.3 oster applyPDA(raidPtr, node->params[i].p, ppda, qpda, node->dagHdr->bp);
320 1.3 oster
321 1.3 oster /* determine the other failed data unit */
322 1.3 oster pda = asmap->failedPDAs[0];
323 1.3 oster sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, asmap->raidAddress);
324 1.3 oster /* need to determine the column of the other failed disk */
325 1.3 oster coeff = rf_RaidAddressToStripeUnitID(layoutPtr, pda->raidAddress);
326 1.3 oster /* compute the data unit offset within the column */
327 1.3 oster coeff = (coeff % raidPtr->Layout.numDataCol);
328 1.3 oster for (i = 0; i < numDataCol; i++) {
329 1.3 oster npda.raidAddress = sosAddr + (i * secPerSU);
330 1.3 oster (raidPtr->Layout.map->MapSector) (raidPtr, npda.raidAddress, &(npda.row), &(npda.col), &(npda.startSector), 0);
331 1.3 oster /* skip over dead disks */
332 1.3 oster if (RF_DEAD_DISK(raidPtr->Disks[npda.row][npda.col].status))
333 1.3 oster if (i != coeff)
334 1.3 oster break;
335 1.3 oster }
336 1.3 oster RF_ASSERT(i < numDataCol);
337 1.3 oster /* recover the data. The column we want to recover we write over the
338 1.3 oster * parity. The column we don't care about we dump in q. */
339 1.3 oster if (coeff < i) /* recovering 'a' */
340 1.3 oster rf_PQ_recover((unsigned long *) ppda->bufPtr, (unsigned long *) qpda->bufPtr, (unsigned long *) ppda->bufPtr, (unsigned long *) qpda->bufPtr, rf_RaidAddressToByte(raidPtr, pda->numSector), coeff, i);
341 1.3 oster else /* recovering 'b' */
342 1.3 oster rf_PQ_recover((unsigned long *) ppda->bufPtr, (unsigned long *) qpda->bufPtr, (unsigned long *) qpda->bufPtr, (unsigned long *) ppda->bufPtr, rf_RaidAddressToByte(raidPtr, pda->numSector), i, coeff);
343 1.3 oster
344 1.3 oster /* OK. The valid data is in P. Zero fill Q, then inc it into it. */
345 1.6 thorpej memset(qpda->bufPtr, 0, rf_RaidAddressToByte(raidPtr, qpda->numSector));
346 1.3 oster rf_IncQ((unsigned long *) qpda->bufPtr, (unsigned long *) ppda->bufPtr, rf_RaidAddressToByte(raidPtr, qpda->numSector), i);
347 1.3 oster
348 1.3 oster /* now apply all the write data to the buffer */
349 1.3 oster /* single stripe unit write case: the failed data is only thing we are
350 1.3 oster * writing. */
351 1.3 oster RF_ASSERT(asmap->numStripeUnitsAccessed == 1);
352 1.3 oster /* dest, src, len, coeff */
353 1.3 oster rf_IncQ((unsigned long *) qpda->bufPtr, (unsigned long *) asmap->failedPDAs[0]->bufPtr, rf_RaidAddressToByte(raidPtr, qpda->numSector), coeff);
354 1.3 oster rf_bxor(asmap->failedPDAs[0]->bufPtr, ppda->bufPtr, rf_RaidAddressToByte(raidPtr, ppda->numSector), node->dagHdr->bp);
355 1.3 oster
356 1.3 oster /* now apply all the recovery data */
357 1.3 oster for (i = 0; i < numDataCol - 2; i++)
358 1.3 oster applyPDA(raidPtr, node->params[i].p, ppda, qpda, node->dagHdr->bp);
359 1.3 oster
360 1.3 oster RF_ETIMER_STOP(timer);
361 1.3 oster RF_ETIMER_EVAL(timer);
362 1.3 oster if (tracerec)
363 1.3 oster tracerec->q_us += RF_ETIMER_VAL_US(timer);
364 1.1 oster
365 1.3 oster rf_GenericWakeupFunc(node, 0);
366 1.3 oster return (0);
367 1.1 oster }
368 1.1 oster RF_CREATE_DAG_FUNC_DECL(rf_PQ_DDLargeWrite)
369 1.1 oster {
370 1.3 oster RF_PANIC();
371 1.1 oster }
372 1.1 oster /*
373 1.1 oster Two lost data unit write case.
374 1.1 oster
375 1.1 oster There are really two cases here:
376 1.1 oster
377 1.3 oster (1) The write completely covers the two lost data units.
378 1.1 oster In that case, a reconstruct write that doesn't write the
379 1.1 oster failed data units will do the correct thing. So in this case,
380 1.1 oster the dag looks like
381 1.1 oster
382 1.1 oster full stripe read of surviving data units (not being overwriten)
383 1.1 oster write new data (ignoring failed units) compute P&Q
384 1.1 oster write P&Q
385 1.1 oster
386 1.1 oster
387 1.1 oster (2) The write does not completely cover both failed data units
388 1.3 oster (but touches at least one of them). Then we need to do the
389 1.1 oster equivalent of a reconstruct read to recover the missing data
390 1.3 oster unit from the other stripe.
391 1.3 oster
392 1.1 oster For any data we are writing that is not in the "shadow"
393 1.1 oster of the failed units, we need to do a four cycle update.
394 1.1 oster PANIC on this case. for now
395 1.1 oster
396 1.1 oster */
397 1.1 oster
398 1.1 oster RF_CREATE_DAG_FUNC_DECL(rf_PQ_200_CreateWriteDAG)
399 1.1 oster {
400 1.3 oster RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
401 1.3 oster RF_SectorCount_t sectorsPerSU = layoutPtr->sectorsPerStripeUnit;
402 1.3 oster int sum;
403 1.3 oster int nf = asmap->numDataFailed;
404 1.3 oster
405 1.3 oster sum = asmap->failedPDAs[0]->numSector;
406 1.3 oster if (nf == 2)
407 1.3 oster sum += asmap->failedPDAs[1]->numSector;
408 1.3 oster
409 1.3 oster if ((nf == 2) && (sum == (2 * sectorsPerSU))) {
410 1.3 oster /* large write case */
411 1.3 oster rf_PQ_DDLargeWrite(raidPtr, asmap, dag_h, bp, flags, allocList);
412 1.3 oster return;
413 1.3 oster }
414 1.3 oster if ((nf == asmap->numStripeUnitsAccessed) || (sum >= sectorsPerSU)) {
415 1.3 oster /* small write case, no user data not in shadow */
416 1.3 oster rf_PQ_DDSimpleSmallWrite(raidPtr, asmap, dag_h, bp, flags, allocList);
417 1.3 oster return;
418 1.3 oster }
419 1.3 oster RF_PANIC();
420 1.1 oster }
421 1.1 oster RF_CREATE_DAG_FUNC_DECL(rf_PQ_DDSimpleSmallWrite)
422 1.1 oster {
423 1.3 oster rf_DoubleDegSmallWrite(raidPtr, asmap, dag_h, bp, flags, allocList, "Rq", "Wq", "PQ Recovery", rf_PQWriteDoubleRecoveryFunc);
424 1.1 oster }
425 1.3 oster #endif /* (RF_INCLUDE_DECL_PQ > 0) ||
426 1.3 oster * (RF_INCLUDE_RAID6 > 0) */
427