1 /* $NetBSD: rf_reconmap.c,v 1.36 2017/11/14 14:27:54 christos 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 1.36 2017/11/14 14:27:54 christos 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 int error; 90 91 RF_Malloc(p, sizeof(RF_ReconMap_t), (RF_ReconMap_t *)); 92 p->sectorsPerReconUnit = ru_sectors; 93 p->sectorsInDisk = disk_sectors; 94 95 p->totalRUs = num_rus; 96 p->spareRUs = spareUnitsPerDisk; 97 p->unitsLeft = num_rus - spareUnitsPerDisk; 98 p->low_ru = 0; 99 p->status_size = RF_RECONMAP_SIZE; 100 p->high_ru = p->status_size - 1; 101 p->head = 0; 102 103 RF_Malloc(p->status, p->status_size * sizeof(RF_ReconMapListElem_t *), (RF_ReconMapListElem_t **)); 104 RF_ASSERT(p->status != NULL); 105 106 (void) memset((char *) p->status, 0, 107 p->status_size * sizeof(RF_ReconMapListElem_t *)); 108 109 pool_init(&p->elem_pool, sizeof(RF_ReconMapListElem_t), 0, 110 0, 0, "raidreconpl", NULL, IPL_BIO); 111 if ((error = pool_prime(&p->elem_pool, RF_NUM_RECON_POOL_ELEM)) != 0) 112 panic("%s: failed to prime pool: %d", __func__, error); 113 114 rf_init_mutex2(p->mutex, IPL_VM); 115 rf_init_cond2(p->cv, "reconupdate"); 116 117 return (p); 118 } 119 120 121 /*--------------------------------------------------------------------------- 122 * 123 * marks a new set of sectors as reconstructed. All the possible 124 * mergings get complicated. To simplify matters, the approach I take 125 * is to just dump something into the list, and then clean it up 126 * (i.e. merge elements and eliminate redundant ones) in a second pass 127 * over the list (compact_stat_entry()). Not 100% efficient, since a 128 * structure can be allocated and then immediately freed, but it keeps 129 * this code from becoming (more of) a nightmare of special cases. 130 * The only thing that compact_stat_entry() assumes is that the list 131 * is sorted by startSector, and so this is the only condition I 132 * maintain here. (MCH) 133 * 134 * This code now uses a pool instead of the previous malloc/free 135 * stuff. 136 *-------------------------------------------------------------------------*/ 137 138 void 139 rf_ReconMapUpdate(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, 140 RF_SectorNum_t startSector, RF_SectorNum_t stopSector) 141 { 142 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 143 RF_SectorNum_t i, first_in_RU, last_in_RU, ru; 144 RF_ReconMapListElem_t *p, *pt; 145 146 rf_lock_mutex2(mapPtr->mutex); 147 while(mapPtr->lock) { 148 rf_wait_cond2(mapPtr->cv, mapPtr->mutex); 149 } 150 mapPtr->lock = 1; 151 rf_unlock_mutex2(mapPtr->mutex); 152 RF_ASSERT(startSector >= 0 && stopSector < mapPtr->sectorsInDisk && 153 stopSector >= startSector); 154 155 while (startSector <= stopSector) { 156 i = startSector / mapPtr->sectorsPerReconUnit; 157 first_in_RU = i * sectorsPerReconUnit; 158 last_in_RU = first_in_RU + sectorsPerReconUnit - 1; 159 160 /* do we need to move the queue? */ 161 while (i > mapPtr->high_ru) { 162 #if 0 163 #ifdef DIAGNOSTIC 164 /* XXX: The check below is not valid for 165 * RAID5_RS. It is valid for RAID 1 and RAID 5. 166 * The issue is that we can easily have 167 * RU_NOTHING entries here too, and those are 168 * quite correct. 169 */ 170 if (mapPtr->status[mapPtr->head]!=RU_ALL) { 171 printf("\nraid%d: reconmap incorrect -- working on i %" PRIu64 "\n", 172 raidPtr->raidid, i); 173 printf("raid%d: ru %" PRIu64 " not completed!!!\n", 174 raidPtr->raidid, mapPtr->head); 175 176 printf("raid%d: low: %" PRIu64 " high: %" PRIu64 "\n", 177 raidPtr->raidid, mapPtr->low_ru, mapPtr->high_ru); 178 179 panic("reconmap incorrect"); 180 } 181 #endif 182 #endif 183 mapPtr->low_ru++; 184 mapPtr->high_ru++; 185 /* initialize "highest" RU status entry, which 186 will take over the current head postion */ 187 mapPtr->status[mapPtr->head]=RU_NOTHING; 188 189 /* move head too */ 190 mapPtr->head++; 191 if (mapPtr->head >= mapPtr->status_size) 192 mapPtr->head = 0; 193 194 } 195 196 ru = i - mapPtr->low_ru + mapPtr->head; 197 if (ru >= mapPtr->status_size) 198 ru = ru - mapPtr->status_size; 199 200 if ((ru < 0) || (ru >= mapPtr->status_size)) { 201 printf("raid%d: ru is bogus %" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "\n", 202 raidPtr->raidid, i, ru, mapPtr->head, mapPtr->low_ru, mapPtr->high_ru); 203 panic("bogus ru in reconmap"); 204 } 205 206 p = mapPtr->status[ru]; 207 if (p != RU_ALL) { 208 if (p == RU_NOTHING || p->startSector > startSector) { 209 /* insert at front of list */ 210 211 mapPtr->status[ru] = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), (p == RU_NOTHING) ? NULL : p); 212 213 } else {/* general case */ 214 do { /* search for place to insert */ 215 pt = p; 216 p = p->next; 217 } while (p && (p->startSector < startSector)); 218 pt->next = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), p); 219 220 } 221 compact_stat_entry(raidPtr, mapPtr, i, ru); 222 } 223 startSector = RF_MIN(stopSector, last_in_RU) + 1; 224 } 225 rf_lock_mutex2(mapPtr->mutex); 226 mapPtr->lock = 0; 227 rf_broadcast_cond2(mapPtr->cv); 228 rf_unlock_mutex2(mapPtr->mutex); 229 } 230 231 232 233 /*--------------------------------------------------------------------------- 234 * 235 * performs whatever list compactions can be done, and frees any space 236 * that is no longer necessary. Assumes only that the list is sorted 237 * by startSector. crunch_list() compacts a single list as much as 238 * possible, and the second block of code deletes the entire list if 239 * possible. crunch_list() is also called from 240 * MakeReconMapAccessList(). 241 * 242 * When a recon unit is detected to be fully reconstructed, we set the 243 * corresponding bit in the parity stripe map so that the head follow 244 * code will not select this parity stripe again. This is redundant 245 * (but harmless) when compact_stat_entry is called from the 246 * reconstruction code, but necessary when called from the user-write 247 * code. 248 * 249 *-------------------------------------------------------------------------*/ 250 251 static void 252 compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, int i, int j) 253 { 254 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 255 RF_ReconMapListElem_t *p = mapPtr->status[j]; 256 257 crunch_list(mapPtr, p); 258 259 if ((p->startSector == i * sectorsPerReconUnit) && 260 (p->stopSector == i * sectorsPerReconUnit + 261 sectorsPerReconUnit - 1)) { 262 mapPtr->status[j] = RU_ALL; 263 mapPtr->unitsLeft--; 264 FreeReconMapListElem(mapPtr, p); 265 } 266 } 267 268 269 static void 270 crunch_list(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *listPtr) 271 { 272 RF_ReconMapListElem_t *pt, *p = listPtr; 273 274 if (!p) 275 return; 276 pt = p; 277 p = p->next; 278 while (p) { 279 if (pt->stopSector >= p->startSector - 1) { 280 pt->stopSector = RF_MAX(pt->stopSector, p->stopSector); 281 pt->next = p->next; 282 FreeReconMapListElem(mapPtr, p); 283 p = pt->next; 284 } else { 285 pt = p; 286 p = p->next; 287 } 288 } 289 } 290 /*--------------------------------------------------------------------------- 291 * 292 * Allocate and fill a new list element 293 * 294 *-------------------------------------------------------------------------*/ 295 296 static RF_ReconMapListElem_t * 297 MakeReconMapListElem(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector, 298 RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next) 299 { 300 RF_ReconMapListElem_t *p; 301 302 p = pool_get(&mapPtr->elem_pool, PR_WAITOK); 303 p->startSector = startSector; 304 p->stopSector = stopSector; 305 p->next = next; 306 return (p); 307 } 308 /*--------------------------------------------------------------------------- 309 * 310 * Free a list element 311 * 312 *-------------------------------------------------------------------------*/ 313 314 static void 315 FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p) 316 { 317 pool_put(&mapPtr->elem_pool, p); 318 } 319 /*--------------------------------------------------------------------------- 320 * 321 * Free an entire status structure. Inefficient, but can be called at 322 * any time. 323 * 324 *-------------------------------------------------------------------------*/ 325 void 326 rf_FreeReconMap(RF_ReconMap_t *mapPtr) 327 { 328 RF_ReconMapListElem_t *p, *q; 329 RF_ReconUnitNum_t i; 330 331 for (i = 0; i < mapPtr->status_size; i++) { 332 p = mapPtr->status[i]; 333 while (p != RU_NOTHING && p != RU_ALL) { 334 q = p; 335 p = p->next; 336 RF_Free(q, sizeof(*q)); 337 } 338 } 339 340 rf_destroy_mutex2(mapPtr->mutex); 341 rf_destroy_cond2(mapPtr->cv); 342 343 pool_destroy(&mapPtr->elem_pool); 344 RF_Free(mapPtr->status, mapPtr->status_size * 345 sizeof(RF_ReconMapListElem_t *)); 346 RF_Free(mapPtr, sizeof(RF_ReconMap_t)); 347 } 348 /*--------------------------------------------------------------------------- 349 * 350 * returns nonzero if the indicated RU has been reconstructed already 351 * 352 *-------------------------------------------------------------------------*/ 353 354 int 355 rf_CheckRUReconstructed(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector) 356 { 357 RF_ReconUnitNum_t i; 358 int rv; 359 360 i = startSector / mapPtr->sectorsPerReconUnit; 361 362 if (i < mapPtr->low_ru) 363 rv = 1; 364 else if (i > mapPtr->high_ru) 365 rv = 0; 366 else { 367 i = i - mapPtr->low_ru + mapPtr->head; 368 if (i >= mapPtr->status_size) 369 i = i - mapPtr->status_size; 370 if (mapPtr->status[i] == RU_ALL) 371 rv = 1; 372 else 373 rv = 0; 374 } 375 376 return rv; 377 } 378 379 RF_ReconUnitCount_t 380 rf_UnitsLeftToReconstruct(RF_ReconMap_t *mapPtr) 381 { 382 RF_ASSERT(mapPtr != NULL); 383 return (mapPtr->unitsLeft); 384 } 385 386 #if RF_DEBUG_RECON 387 void 388 rf_PrintReconSchedule(RF_ReconMap_t *mapPtr, struct timeval *starttime) 389 { 390 static int old_pctg = -1; 391 struct timeval tv, diff; 392 int new_pctg; 393 394 new_pctg = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 395 100 / mapPtr->totalRUs); 396 if (new_pctg != old_pctg) { 397 RF_GETTIME(tv); 398 RF_TIMEVAL_DIFF(starttime, &tv, &diff); 399 printf("%d %d.%06d\n", (int) new_pctg, (int) diff.tv_sec, 400 (int) diff.tv_usec); 401 old_pctg = new_pctg; 402 } 403 } 404 #endif 405 406