1 /* $NetBSD: rf_reconmap.c,v 1.31 2008/05/19 19:49:54 oster Exp $ */ 2 /* 3 * Copyright (c) 1995 Carnegie-Mellon University. 4 * All rights reserved. 5 * 6 * Author: Mark Holland 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_reconmap.c 31 * 32 * code to maintain a map of what sectors have/have not been reconstructed 33 * 34 *************************************************************************/ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: rf_reconmap.c,v 1.31 2008/05/19 19:49:54 oster Exp $"); 38 39 #include "rf_raid.h" 40 #include <sys/time.h> 41 #include "rf_general.h" 42 #include "rf_utils.h" 43 44 /* special pointer values indicating that a reconstruction unit 45 * has been either totally reconstructed or not at all. Both 46 * are illegal pointer values, so you have to be careful not to 47 * dereference through them. RU_NOTHING must be zero, since 48 * MakeReconMap uses memset to initialize the structure. These are used 49 * only at the head of the list. 50 */ 51 #define RU_ALL ((RF_ReconMapListElem_t *) -1) 52 #define RU_NOTHING ((RF_ReconMapListElem_t *) 0) 53 54 /* For most reconstructs we need at most 3 RF_ReconMapListElem_t's. 55 * Bounding the number we need is quite difficult, as it depends on how 56 * badly the sectors to be reconstructed get divided up. In the current 57 * code, the reconstructed sectors appeared aligned on stripe boundaries, 58 * and are always presented in stripe width units, so we're probably 59 * allocating quite a bit more than we'll ever need. 60 */ 61 #define RF_NUM_RECON_POOL_ELEM 100 62 63 static void 64 compact_stat_entry(RF_Raid_t *, RF_ReconMap_t *, int, int); 65 static void crunch_list(RF_ReconMap_t *, RF_ReconMapListElem_t *); 66 static RF_ReconMapListElem_t * 67 MakeReconMapListElem(RF_ReconMap_t *, RF_SectorNum_t, RF_SectorNum_t, 68 RF_ReconMapListElem_t *); 69 static void 70 FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t * p); 71 72 /*--------------------------------------------------------------------------- 73 * 74 * Creates and initializes new Reconstruction map 75 * 76 * ru_sectors - size of reconstruction unit in sectors 77 * disk_sectors - size of disk in sectors 78 * spareUnitsPerDisk - zero unless distributed sparing 79 *-------------------------------------------------------------------------*/ 80 81 RF_ReconMap_t * 82 rf_MakeReconMap(RF_Raid_t *raidPtr, RF_SectorCount_t ru_sectors, 83 RF_SectorCount_t disk_sectors, 84 RF_ReconUnitCount_t spareUnitsPerDisk) 85 { 86 RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; 87 RF_ReconUnitCount_t num_rus = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerRU; 88 RF_ReconMap_t *p; 89 90 RF_Malloc(p, sizeof(RF_ReconMap_t), (RF_ReconMap_t *)); 91 p->sectorsPerReconUnit = ru_sectors; 92 p->sectorsInDisk = disk_sectors; 93 94 p->totalRUs = num_rus; 95 p->spareRUs = spareUnitsPerDisk; 96 p->unitsLeft = num_rus - spareUnitsPerDisk; 97 p->low_ru = 0; 98 p->status_size = RF_RECONMAP_SIZE; 99 p->high_ru = p->status_size - 1; 100 p->head = 0; 101 102 RF_Malloc(p->status, p->status_size * sizeof(RF_ReconMapListElem_t *), (RF_ReconMapListElem_t **)); 103 RF_ASSERT(p->status != (RF_ReconMapListElem_t **) NULL); 104 105 (void) memset((char *) p->status, 0, 106 p->status_size * sizeof(RF_ReconMapListElem_t *)); 107 108 pool_init(&p->elem_pool, sizeof(RF_ReconMapListElem_t), 0, 109 0, 0, "raidreconpl", NULL, IPL_BIO); 110 pool_prime(&p->elem_pool, RF_NUM_RECON_POOL_ELEM); 111 112 rf_mutex_init(&p->mutex); 113 return (p); 114 } 115 116 117 /*--------------------------------------------------------------------------- 118 * 119 * marks a new set of sectors as reconstructed. All the possible 120 * mergings get complicated. To simplify matters, the approach I take 121 * is to just dump something into the list, and then clean it up 122 * (i.e. merge elements and eliminate redundant ones) in a second pass 123 * over the list (compact_stat_entry()). Not 100% efficient, since a 124 * structure can be allocated and then immediately freed, but it keeps 125 * this code from becoming (more of) a nightmare of special cases. 126 * The only thing that compact_stat_entry() assumes is that the list 127 * is sorted by startSector, and so this is the only condition I 128 * maintain here. (MCH) 129 * 130 * This code now uses a pool instead of the previous malloc/free 131 * stuff. 132 *-------------------------------------------------------------------------*/ 133 134 void 135 rf_ReconMapUpdate(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, 136 RF_SectorNum_t startSector, RF_SectorNum_t stopSector) 137 { 138 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 139 RF_SectorNum_t i, first_in_RU, last_in_RU, ru; 140 RF_ReconMapListElem_t *p, *pt; 141 142 RF_LOCK_MUTEX(mapPtr->mutex); 143 while(mapPtr->lock) { 144 ltsleep(&mapPtr->lock, PRIBIO, "reconupdate", 0, 145 &mapPtr->mutex); 146 } 147 mapPtr->lock = 1; 148 RF_UNLOCK_MUTEX(mapPtr->mutex); 149 RF_ASSERT(startSector >= 0 && stopSector < mapPtr->sectorsInDisk && 150 stopSector >= startSector); 151 152 while (startSector <= stopSector) { 153 i = startSector / mapPtr->sectorsPerReconUnit; 154 first_in_RU = i * sectorsPerReconUnit; 155 last_in_RU = first_in_RU + sectorsPerReconUnit - 1; 156 157 /* do we need to move the queue? */ 158 while (i > mapPtr->high_ru) { 159 #ifdef DIAGNOSTIC 160 if (mapPtr->status[mapPtr->head]!=RU_ALL) { 161 printf("\nraid%d: reconmap incorrect -- working on i %" PRIu64 "\n", 162 raidPtr->raidid, i); 163 printf("raid%d: ru %" PRIu64 " not completed!!!\n", 164 raidPtr->raidid, mapPtr->head); 165 166 printf("raid%d: low: %" PRIu64 " high: %" PRIu64 "\n", 167 raidPtr->raidid, mapPtr->low_ru, mapPtr->high_ru); 168 169 panic("reconmap incorrect"); 170 } 171 #endif 172 mapPtr->low_ru++; 173 mapPtr->high_ru++; 174 /* initialize "highest" RU status entry, which 175 will take over the current head postion */ 176 mapPtr->status[mapPtr->head]=RU_NOTHING; 177 178 /* move head too */ 179 mapPtr->head++; 180 if (mapPtr->head >= mapPtr->status_size) 181 mapPtr->head = 0; 182 183 } 184 185 ru = i - mapPtr->low_ru + mapPtr->head; 186 if (ru >= mapPtr->status_size) 187 ru = ru - mapPtr->status_size; 188 189 if ((ru < 0) || (ru >= mapPtr->status_size)) { 190 printf("raid%d: ru is bogus %" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "\n", 191 raidPtr->raidid, i, ru, mapPtr->head, mapPtr->low_ru, mapPtr->high_ru); 192 panic("bogus ru in reconmap"); 193 } 194 195 p = mapPtr->status[ru]; 196 if (p != RU_ALL) { 197 if (p == RU_NOTHING || p->startSector > startSector) { 198 /* insert at front of list */ 199 200 mapPtr->status[ru] = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), (p == RU_NOTHING) ? NULL : p); 201 202 } else {/* general case */ 203 do { /* search for place to insert */ 204 pt = p; 205 p = p->next; 206 } while (p && (p->startSector < startSector)); 207 pt->next = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), p); 208 209 } 210 compact_stat_entry(raidPtr, mapPtr, i, ru); 211 } 212 startSector = RF_MIN(stopSector, last_in_RU) + 1; 213 } 214 RF_LOCK_MUTEX(mapPtr->mutex); 215 mapPtr->lock = 0; 216 wakeup(&mapPtr->lock); 217 RF_UNLOCK_MUTEX(mapPtr->mutex); 218 } 219 220 221 222 /*--------------------------------------------------------------------------- 223 * 224 * performs whatever list compactions can be done, and frees any space 225 * that is no longer necessary. Assumes only that the list is sorted 226 * by startSector. crunch_list() compacts a single list as much as 227 * possible, and the second block of code deletes the entire list if 228 * possible. crunch_list() is also called from 229 * MakeReconMapAccessList(). 230 * 231 * When a recon unit is detected to be fully reconstructed, we set the 232 * corresponding bit in the parity stripe map so that the head follow 233 * code will not select this parity stripe again. This is redundant 234 * (but harmless) when compact_stat_entry is called from the 235 * reconstruction code, but necessary when called from the user-write 236 * code. 237 * 238 *-------------------------------------------------------------------------*/ 239 240 static void 241 compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, int i, int j) 242 { 243 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 244 RF_ReconMapListElem_t *p = mapPtr->status[j]; 245 246 crunch_list(mapPtr, p); 247 248 if ((p->startSector == i * sectorsPerReconUnit) && 249 (p->stopSector == i * sectorsPerReconUnit + 250 sectorsPerReconUnit - 1)) { 251 mapPtr->status[j] = RU_ALL; 252 mapPtr->unitsLeft--; 253 FreeReconMapListElem(mapPtr, p); 254 } 255 } 256 257 258 static void 259 crunch_list(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *listPtr) 260 { 261 RF_ReconMapListElem_t *pt, *p = listPtr; 262 263 if (!p) 264 return; 265 pt = p; 266 p = p->next; 267 while (p) { 268 if (pt->stopSector >= p->startSector - 1) { 269 pt->stopSector = RF_MAX(pt->stopSector, p->stopSector); 270 pt->next = p->next; 271 FreeReconMapListElem(mapPtr, p); 272 p = pt->next; 273 } else { 274 pt = p; 275 p = p->next; 276 } 277 } 278 } 279 /*--------------------------------------------------------------------------- 280 * 281 * Allocate and fill a new list element 282 * 283 *-------------------------------------------------------------------------*/ 284 285 static RF_ReconMapListElem_t * 286 MakeReconMapListElem(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector, 287 RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next) 288 { 289 RF_ReconMapListElem_t *p; 290 291 p = pool_get(&mapPtr->elem_pool, PR_WAITOK); 292 p->startSector = startSector; 293 p->stopSector = stopSector; 294 p->next = next; 295 return (p); 296 } 297 /*--------------------------------------------------------------------------- 298 * 299 * Free a list element 300 * 301 *-------------------------------------------------------------------------*/ 302 303 static void 304 FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p) 305 { 306 pool_put(&mapPtr->elem_pool, p); 307 } 308 /*--------------------------------------------------------------------------- 309 * 310 * Free an entire status structure. Inefficient, but can be called at 311 * any time. 312 * 313 *-------------------------------------------------------------------------*/ 314 void 315 rf_FreeReconMap(RF_ReconMap_t *mapPtr) 316 { 317 RF_ReconMapListElem_t *p, *q; 318 RF_ReconUnitCount_t numRUs; 319 RF_ReconUnitNum_t i; 320 321 numRUs = mapPtr->sectorsInDisk / mapPtr->sectorsPerReconUnit; 322 if (mapPtr->sectorsInDisk % mapPtr->sectorsPerReconUnit) 323 numRUs++; 324 325 for (i = 0; i < mapPtr->status_size; i++) { 326 p = mapPtr->status[i]; 327 while (p != RU_NOTHING && p != RU_ALL) { 328 q = p; 329 p = p->next; 330 RF_Free(q, sizeof(*q)); 331 } 332 } 333 334 pool_destroy(&mapPtr->elem_pool); 335 RF_Free(mapPtr->status, mapPtr->status_size * 336 sizeof(RF_ReconMapListElem_t *)); 337 RF_Free(mapPtr, sizeof(RF_ReconMap_t)); 338 } 339 /*--------------------------------------------------------------------------- 340 * 341 * returns nonzero if the indicated RU has been reconstructed already 342 * 343 *-------------------------------------------------------------------------*/ 344 345 int 346 rf_CheckRUReconstructed(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector) 347 { 348 RF_ReconUnitNum_t i; 349 int rv; 350 351 i = startSector / mapPtr->sectorsPerReconUnit; 352 353 if (i < mapPtr->low_ru) 354 rv = 1; 355 else if (i > mapPtr->high_ru) 356 rv = 0; 357 else { 358 i = i - mapPtr->low_ru + mapPtr->head; 359 if (i >= mapPtr->status_size) 360 i = i - mapPtr->status_size; 361 if (mapPtr->status[i] == RU_ALL) 362 rv = 1; 363 else 364 rv = 0; 365 } 366 367 return rv; 368 } 369 370 RF_ReconUnitCount_t 371 rf_UnitsLeftToReconstruct(RF_ReconMap_t *mapPtr) 372 { 373 RF_ASSERT(mapPtr != NULL); 374 return (mapPtr->unitsLeft); 375 } 376 377 #if RF_DEBUG_RECON 378 void 379 rf_PrintReconSchedule(RF_ReconMap_t *mapPtr, struct timeval *starttime) 380 { 381 static int old_pctg = -1; 382 struct timeval tv, diff; 383 int new_pctg; 384 385 new_pctg = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 386 100 / mapPtr->totalRUs); 387 if (new_pctg != old_pctg) { 388 RF_GETTIME(tv); 389 RF_TIMEVAL_DIFF(starttime, &tv, &diff); 390 printf("%d %d.%06d\n", (int) new_pctg, (int) diff.tv_sec, 391 (int) diff.tv_usec); 392 old_pctg = new_pctg; 393 } 394 } 395 #endif 396 397