1 | /* $NetBSD: rf_dagffrd.c,v 1.19 2013/09/15 12:23:06 martin Exp $ */ |
2 | /* |
3 | * Copyright (c) 1995 Carnegie-Mellon University. |
4 | * All rights reserved. |
5 | * |
6 | * Author: Mark Holland, Daniel Stodolsky, William V. Courtright II |
7 | * |
8 | * Permission to use, copy, modify and distribute this software and |
9 | * its documentation is hereby granted, provided that both the copyright |
10 | * notice and this permission notice appear in all copies of the |
11 | * software, derivative works or modified versions, and any portions |
12 | * thereof, and that both notices appear in supporting documentation. |
13 | * |
14 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
15 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND |
16 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
17 | * |
18 | * Carnegie Mellon requests users of this software to return to |
19 | * |
20 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
21 | * School of Computer Science |
22 | * Carnegie Mellon University |
23 | * Pittsburgh PA 15213-3890 |
24 | * |
25 | * any improvements or extensions that they make and grant Carnegie the |
26 | * rights to redistribute these changes. |
27 | */ |
28 | |
29 | /* |
30 | * rf_dagffrd.c |
31 | * |
32 | * code for creating fault-free read DAGs |
33 | * |
34 | */ |
35 | |
36 | #include <sys/cdefs.h> |
37 | __KERNEL_RCSID(0, "$NetBSD: rf_dagffrd.c,v 1.19 2013/09/15 12:23:06 martin Exp $" ); |
38 | |
39 | #include <dev/raidframe/raidframevar.h> |
40 | |
41 | #include "rf_raid.h" |
42 | #include "rf_dag.h" |
43 | #include "rf_dagutils.h" |
44 | #include "rf_dagfuncs.h" |
45 | #include "rf_debugMem.h" |
46 | #include "rf_general.h" |
47 | #include "rf_dagffrd.h" |
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 | void |
77 | rf_CreateFaultFreeReadDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap, |
78 | RF_DagHeader_t *dag_h, void *bp, |
79 | RF_RaidAccessFlags_t flags, |
80 | RF_AllocListElem_t *allocList) |
81 | { |
82 | rf_CreateNonredundantDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
83 | RF_IO_TYPE_READ); |
84 | } |
85 | |
86 | |
87 | /****************************************************************************** |
88 | * |
89 | * DAG creation code begins here |
90 | */ |
91 | |
92 | /****************************************************************************** |
93 | * |
94 | * creates a DAG to perform a nonredundant read or write of data within one |
95 | * stripe. |
96 | * For reads, this DAG is as follows: |
97 | * |
98 | * /---- read ----\ |
99 | * Header -- Block ---- read ---- Commit -- Terminate |
100 | * \---- read ----/ |
101 | * |
102 | * For writes, this DAG is as follows: |
103 | * |
104 | * /---- write ----\ |
105 | * Header -- Commit ---- write ---- Block -- Terminate |
106 | * \---- write ----/ |
107 | * |
108 | * There is one disk node per stripe unit accessed, and all disk nodes are in |
109 | * parallel. |
110 | * |
111 | * Tricky point here: The first disk node (read or write) is created |
112 | * normally. Subsequent disk nodes are created by copying the first one, |
113 | * and modifying a few params. The "succedents" and "antecedents" fields are |
114 | * _not_ re-created in each node, but rather left pointing to the same array |
115 | * that was malloc'd when the first node was created. Thus, it's essential |
116 | * that when this DAG is freed, the succedents and antecedents fields be freed |
117 | * in ONLY ONE of the read nodes. This does not apply to the "params" field |
118 | * because it is recreated for each READ node. |
119 | * |
120 | * Note that normal-priority accesses do not need to be tagged with their |
121 | * parity stripe ID, because they will never be promoted. Hence, I've |
122 | * commented-out the code to do this, and marked it with UNNEEDED. |
123 | * |
124 | *****************************************************************************/ |
125 | |
126 | void |
127 | rf_CreateNonredundantDAG(RF_Raid_t *raidPtr, |
128 | RF_AccessStripeMap_t *asmap, RF_DagHeader_t *dag_h, void *bp, |
129 | RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, |
130 | RF_IoType_t type) |
131 | { |
132 | RF_DagNode_t *diskNodes, *blockNode, *commitNode, *termNode; |
133 | RF_DagNode_t *tmpNode, *tmpdiskNode; |
134 | RF_PhysDiskAddr_t *pda = asmap->physInfo; |
135 | int (*doFunc) (RF_DagNode_t *), (*undoFunc) (RF_DagNode_t *); |
136 | int i, n; |
137 | const char *name; |
138 | |
139 | n = asmap->numStripeUnitsAccessed; |
140 | dag_h->creator = "NonredundantDAG" ; |
141 | |
142 | RF_ASSERT(RF_IO_IS_R_OR_W(type)); |
143 | switch (type) { |
144 | case RF_IO_TYPE_READ: |
145 | doFunc = rf_DiskReadFunc; |
146 | undoFunc = rf_DiskReadUndoFunc; |
147 | name = "R " ; |
148 | #if RF_DEBUG_DAG |
149 | if (rf_dagDebug) |
150 | printf("[Creating non-redundant read DAG]\n" ); |
151 | #endif |
152 | break; |
153 | case RF_IO_TYPE_WRITE: |
154 | doFunc = rf_DiskWriteFunc; |
155 | undoFunc = rf_DiskWriteUndoFunc; |
156 | name = "W " ; |
157 | #if RF_DEBUG_DAG |
158 | if (rf_dagDebug) |
159 | printf("[Creating non-redundant write DAG]\n" ); |
160 | #endif |
161 | break; |
162 | default: |
163 | RF_PANIC(); |
164 | } |
165 | |
166 | /* |
167 | * For reads, the dag can not commit until the block node is reached. |
168 | * for writes, the dag commits immediately. |
169 | */ |
170 | dag_h->numCommitNodes = 1; |
171 | dag_h->numCommits = 0; |
172 | dag_h->numSuccedents = 1; |
173 | |
174 | /* |
175 | * Node count: |
176 | * 1 block node |
177 | * n data reads (or writes) |
178 | * 1 commit node |
179 | * 1 terminator node |
180 | */ |
181 | RF_ASSERT(n > 0); |
182 | |
183 | for (i = 0; i < n; i++) { |
184 | tmpNode = rf_AllocDAGNode(); |
185 | tmpNode->list_next = dag_h->nodes; |
186 | dag_h->nodes = tmpNode; |
187 | } |
188 | diskNodes = dag_h->nodes; |
189 | |
190 | blockNode = rf_AllocDAGNode(); |
191 | blockNode->list_next = dag_h->nodes; |
192 | dag_h->nodes = blockNode; |
193 | |
194 | commitNode = rf_AllocDAGNode(); |
195 | commitNode->list_next = dag_h->nodes; |
196 | dag_h->nodes = commitNode; |
197 | |
198 | termNode = rf_AllocDAGNode(); |
199 | termNode->list_next = dag_h->nodes; |
200 | dag_h->nodes = termNode; |
201 | |
202 | /* initialize nodes */ |
203 | switch (type) { |
204 | case RF_IO_TYPE_READ: |
205 | rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
206 | NULL, n, 0, 0, 0, dag_h, "Nil" , allocList); |
207 | rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
208 | NULL, 1, n, 0, 0, dag_h, "Cmt" , allocList); |
209 | rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, |
210 | NULL, 0, 1, 0, 0, dag_h, "Trm" , allocList); |
211 | break; |
212 | case RF_IO_TYPE_WRITE: |
213 | rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
214 | NULL, 1, 0, 0, 0, dag_h, "Nil" , allocList); |
215 | rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
216 | NULL, n, 1, 0, 0, dag_h, "Cmt" , allocList); |
217 | rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, |
218 | NULL, 0, n, 0, 0, dag_h, "Trm" , allocList); |
219 | break; |
220 | default: |
221 | RF_PANIC(); |
222 | } |
223 | |
224 | tmpdiskNode = diskNodes; |
225 | for (i = 0; i < n; i++) { |
226 | RF_ASSERT(pda != NULL); |
227 | rf_InitNode(tmpdiskNode, rf_wait, RF_FALSE, doFunc, undoFunc, rf_GenericWakeupFunc, |
228 | 1, 1, 4, 0, dag_h, name, allocList); |
229 | tmpdiskNode->params[0].p = pda; |
230 | tmpdiskNode->params[1].p = pda->bufPtr; |
231 | /* parity stripe id is not necessary */ |
232 | tmpdiskNode->params[2].v = 0; |
233 | tmpdiskNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0); |
234 | pda = pda->next; |
235 | tmpdiskNode = tmpdiskNode->list_next; |
236 | } |
237 | |
238 | /* |
239 | * Connect nodes. |
240 | */ |
241 | |
242 | /* connect hdr to block node */ |
243 | RF_ASSERT(blockNode->numAntecedents == 0); |
244 | dag_h->succedents[0] = blockNode; |
245 | |
246 | if (type == RF_IO_TYPE_READ) { |
247 | /* connecting a nonredundant read DAG */ |
248 | RF_ASSERT(blockNode->numSuccedents == n); |
249 | RF_ASSERT(commitNode->numAntecedents == n); |
250 | tmpdiskNode = diskNodes; |
251 | for (i = 0; i < n; i++) { |
252 | /* connect block node to each read node */ |
253 | RF_ASSERT(tmpdiskNode->numAntecedents == 1); |
254 | blockNode->succedents[i] = tmpdiskNode; |
255 | tmpdiskNode->antecedents[0] = blockNode; |
256 | tmpdiskNode->antType[0] = rf_control; |
257 | |
258 | /* connect each read node to the commit node */ |
259 | RF_ASSERT(tmpdiskNode->numSuccedents == 1); |
260 | tmpdiskNode->succedents[0] = commitNode; |
261 | commitNode->antecedents[i] = tmpdiskNode; |
262 | commitNode->antType[i] = rf_control; |
263 | tmpdiskNode = tmpdiskNode->list_next; |
264 | } |
265 | /* connect the commit node to the term node */ |
266 | RF_ASSERT(commitNode->numSuccedents == 1); |
267 | RF_ASSERT(termNode->numAntecedents == 1); |
268 | RF_ASSERT(termNode->numSuccedents == 0); |
269 | commitNode->succedents[0] = termNode; |
270 | termNode->antecedents[0] = commitNode; |
271 | termNode->antType[0] = rf_control; |
272 | } else { |
273 | /* connecting a nonredundant write DAG */ |
274 | /* connect the block node to the commit node */ |
275 | RF_ASSERT(blockNode->numSuccedents == 1); |
276 | RF_ASSERT(commitNode->numAntecedents == 1); |
277 | blockNode->succedents[0] = commitNode; |
278 | commitNode->antecedents[0] = blockNode; |
279 | commitNode->antType[0] = rf_control; |
280 | |
281 | RF_ASSERT(commitNode->numSuccedents == n); |
282 | RF_ASSERT(termNode->numAntecedents == n); |
283 | RF_ASSERT(termNode->numSuccedents == 0); |
284 | tmpdiskNode = diskNodes; |
285 | for (i = 0; i < n; i++) { |
286 | /* connect the commit node to each write node */ |
287 | RF_ASSERT(tmpdiskNode->numAntecedents == 1); |
288 | commitNode->succedents[i] = tmpdiskNode; |
289 | tmpdiskNode->antecedents[0] = commitNode; |
290 | tmpdiskNode->antType[0] = rf_control; |
291 | |
292 | /* connect each write node to the term node */ |
293 | RF_ASSERT(tmpdiskNode->numSuccedents == 1); |
294 | tmpdiskNode->succedents[0] = termNode; |
295 | termNode->antecedents[i] = tmpdiskNode; |
296 | termNode->antType[i] = rf_control; |
297 | tmpdiskNode = tmpdiskNode->list_next; |
298 | } |
299 | } |
300 | } |
301 | /****************************************************************************** |
302 | * Create a fault-free read DAG for RAID level 1 |
303 | * |
304 | * Hdr -> Nil -> Rmir -> Cmt -> Trm |
305 | * |
306 | * The "Rmir" node schedules a read from the disk in the mirror pair with the |
307 | * shortest disk queue. the proper queue is selected at Rmir execution. this |
308 | * deferred mapping is unlike other archs in RAIDframe which generally fix |
309 | * mapping at DAG creation time. |
310 | * |
311 | * Parameters: raidPtr - description of the physical array |
312 | * asmap - logical & physical addresses for this access |
313 | * bp - buffer ptr (for holding read data) |
314 | * flags - general flags (e.g. disk locking) |
315 | * allocList - list of memory allocated in DAG creation |
316 | *****************************************************************************/ |
317 | |
318 | static void |
319 | CreateMirrorReadDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap, |
320 | RF_DagHeader_t *dag_h, void *bp, |
321 | RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, |
322 | int (*readfunc) (RF_DagNode_t * node)) |
323 | { |
324 | RF_DagNode_t *readNodes, *blockNode, *commitNode, *termNode; |
325 | RF_DagNode_t *tmpNode, *tmpreadNode; |
326 | RF_PhysDiskAddr_t *data_pda = asmap->physInfo; |
327 | RF_PhysDiskAddr_t *parity_pda = asmap->parityInfo; |
328 | int i, n; |
329 | |
330 | n = asmap->numStripeUnitsAccessed; |
331 | dag_h->creator = "RaidOneReadDAG" ; |
332 | #if RF_DEBUG_DAG |
333 | if (rf_dagDebug) { |
334 | printf("[Creating RAID level 1 read DAG]\n" ); |
335 | } |
336 | #endif |
337 | /* |
338 | * This dag can not commit until the commit node is reached |
339 | * errors prior to the commit point imply the dag has failed. |
340 | */ |
341 | dag_h->numCommitNodes = 1; |
342 | dag_h->numCommits = 0; |
343 | dag_h->numSuccedents = 1; |
344 | |
345 | /* |
346 | * Node count: |
347 | * n data reads |
348 | * 1 block node |
349 | * 1 commit node |
350 | * 1 terminator node |
351 | */ |
352 | RF_ASSERT(n > 0); |
353 | |
354 | for (i = 0; i < n; i++) { |
355 | tmpNode = rf_AllocDAGNode(); |
356 | tmpNode->list_next = dag_h->nodes; |
357 | dag_h->nodes = tmpNode; |
358 | } |
359 | readNodes = dag_h->nodes; |
360 | |
361 | blockNode = rf_AllocDAGNode(); |
362 | blockNode->list_next = dag_h->nodes; |
363 | dag_h->nodes = blockNode; |
364 | |
365 | commitNode = rf_AllocDAGNode(); |
366 | commitNode->list_next = dag_h->nodes; |
367 | dag_h->nodes = commitNode; |
368 | |
369 | termNode = rf_AllocDAGNode(); |
370 | termNode->list_next = dag_h->nodes; |
371 | dag_h->nodes = termNode; |
372 | |
373 | /* initialize nodes */ |
374 | rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, |
375 | rf_NullNodeUndoFunc, NULL, n, 0, 0, 0, dag_h, "Nil" , allocList); |
376 | rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, |
377 | rf_NullNodeUndoFunc, NULL, 1, n, 0, 0, dag_h, "Cmt" , allocList); |
378 | rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, |
379 | rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm" , allocList); |
380 | |
381 | tmpreadNode = readNodes; |
382 | for (i = 0; i < n; i++) { |
383 | RF_ASSERT(data_pda != NULL); |
384 | RF_ASSERT(parity_pda != NULL); |
385 | rf_InitNode(tmpreadNode, rf_wait, RF_FALSE, readfunc, |
386 | rf_DiskReadMirrorUndoFunc, rf_GenericWakeupFunc, 1, 1, 5, 0, dag_h, |
387 | "Rmir" , allocList); |
388 | tmpreadNode->params[0].p = data_pda; |
389 | tmpreadNode->params[1].p = data_pda->bufPtr; |
390 | /* parity stripe id is not necessary */ |
391 | tmpreadNode->params[2].p = 0; |
392 | tmpreadNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0); |
393 | tmpreadNode->params[4].p = parity_pda; |
394 | data_pda = data_pda->next; |
395 | parity_pda = parity_pda->next; |
396 | tmpreadNode = tmpreadNode->list_next; |
397 | } |
398 | |
399 | /* |
400 | * Connect nodes |
401 | */ |
402 | |
403 | /* connect hdr to block node */ |
404 | RF_ASSERT(blockNode->numAntecedents == 0); |
405 | dag_h->succedents[0] = blockNode; |
406 | |
407 | /* connect block node to read nodes */ |
408 | RF_ASSERT(blockNode->numSuccedents == n); |
409 | tmpreadNode = readNodes; |
410 | for (i = 0; i < n; i++) { |
411 | RF_ASSERT(tmpreadNode->numAntecedents == 1); |
412 | blockNode->succedents[i] = tmpreadNode; |
413 | tmpreadNode->antecedents[0] = blockNode; |
414 | tmpreadNode->antType[0] = rf_control; |
415 | tmpreadNode = tmpreadNode->list_next; |
416 | } |
417 | |
418 | /* connect read nodes to commit node */ |
419 | RF_ASSERT(commitNode->numAntecedents == n); |
420 | tmpreadNode = readNodes; |
421 | for (i = 0; i < n; i++) { |
422 | RF_ASSERT(tmpreadNode->numSuccedents == 1); |
423 | tmpreadNode->succedents[0] = commitNode; |
424 | commitNode->antecedents[i] = tmpreadNode; |
425 | commitNode->antType[i] = rf_control; |
426 | tmpreadNode = tmpreadNode->list_next; |
427 | } |
428 | |
429 | /* connect commit node to term node */ |
430 | RF_ASSERT(commitNode->numSuccedents == 1); |
431 | RF_ASSERT(termNode->numAntecedents == 1); |
432 | RF_ASSERT(termNode->numSuccedents == 0); |
433 | commitNode->succedents[0] = termNode; |
434 | termNode->antecedents[0] = commitNode; |
435 | termNode->antType[0] = rf_control; |
436 | } |
437 | |
438 | void |
439 | rf_CreateMirrorIdleReadDAG( |
440 | RF_Raid_t * raidPtr, |
441 | RF_AccessStripeMap_t * asmap, |
442 | RF_DagHeader_t * dag_h, |
443 | void *bp, |
444 | RF_RaidAccessFlags_t flags, |
445 | RF_AllocListElem_t * allocList) |
446 | { |
447 | CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
448 | rf_DiskReadMirrorIdleFunc); |
449 | } |
450 | |
451 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) || (RF_INCLUDE_INTERDECLUSTER > 0) |
452 | |
453 | void |
454 | rf_CreateMirrorPartitionReadDAG(RF_Raid_t *raidPtr, |
455 | RF_AccessStripeMap_t *asmap, |
456 | RF_DagHeader_t *dag_h, void *bp, |
457 | RF_RaidAccessFlags_t flags, |
458 | RF_AllocListElem_t *allocList) |
459 | { |
460 | CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
461 | rf_DiskReadMirrorPartitionFunc); |
462 | } |
463 | #endif |
464 | |