1 /* $NetBSD: rf_reconmap.c,v 1.37 2019/02/09 03:34:00 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 1.37 2019/02/09 03:34:00 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 p = RF_Malloc(sizeof(*p)); 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 p->status = RF_Malloc(p->status_size * sizeof(*p->status)); 104 RF_ASSERT(p->status != NULL); 105 106 pool_init(&p->elem_pool, sizeof(RF_ReconMapListElem_t), 0, 107 0, 0, "raidreconpl", NULL, IPL_BIO); 108 if ((error = pool_prime(&p->elem_pool, RF_NUM_RECON_POOL_ELEM)) != 0) 109 panic("%s: failed to prime pool: %d", __func__, error); 110 111 rf_init_mutex2(p->mutex, IPL_VM); 112 rf_init_cond2(p->cv, "reconupdate"); 113 114 return (p); 115 } 116 117 118 /*--------------------------------------------------------------------------- 119 * 120 * marks a new set of sectors as reconstructed. All the possible 121 * mergings get complicated. To simplify matters, the approach I take 122 * is to just dump something into the list, and then clean it up 123 * (i.e. merge elements and eliminate redundant ones) in a second pass 124 * over the list (compact_stat_entry()). Not 100% efficient, since a 125 * structure can be allocated and then immediately freed, but it keeps 126 * this code from becoming (more of) a nightmare of special cases. 127 * The only thing that compact_stat_entry() assumes is that the list 128 * is sorted by startSector, and so this is the only condition I 129 * maintain here. (MCH) 130 * 131 * This code now uses a pool instead of the previous malloc/free 132 * stuff. 133 *-------------------------------------------------------------------------*/ 134 135 void 136 rf_ReconMapUpdate(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, 137 RF_SectorNum_t startSector, RF_SectorNum_t stopSector) 138 { 139 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 140 RF_SectorNum_t i, first_in_RU, last_in_RU, ru; 141 RF_ReconMapListElem_t *p, *pt; 142 143 rf_lock_mutex2(mapPtr->mutex); 144 while(mapPtr->lock) { 145 rf_wait_cond2(mapPtr->cv, mapPtr->mutex); 146 } 147 mapPtr->lock = 1; 148 rf_unlock_mutex2(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 #if 0 160 #ifdef DIAGNOSTIC 161 /* XXX: The check below is not valid for 162 * RAID5_RS. It is valid for RAID 1 and RAID 5. 163 * The issue is that we can easily have 164 * RU_NOTHING entries here too, and those are 165 * quite correct. 166 */ 167 if (mapPtr->status[mapPtr->head]!=RU_ALL) { 168 printf("\nraid%d: reconmap incorrect -- working on i %" PRIu64 "\n", 169 raidPtr->raidid, i); 170 printf("raid%d: ru %" PRIu64 " not completed!!!\n", 171 raidPtr->raidid, mapPtr->head); 172 173 printf("raid%d: low: %" PRIu64 " high: %" PRIu64 "\n", 174 raidPtr->raidid, mapPtr->low_ru, mapPtr->high_ru); 175 176 panic("reconmap incorrect"); 177 } 178 #endif 179 #endif 180 mapPtr->low_ru++; 181 mapPtr->high_ru++; 182 /* initialize "highest" RU status entry, which 183 will take over the current head postion */ 184 mapPtr->status[mapPtr->head]=RU_NOTHING; 185 186 /* move head too */ 187 mapPtr->head++; 188 if (mapPtr->head >= mapPtr->status_size) 189 mapPtr->head = 0; 190 191 } 192 193 ru = i - mapPtr->low_ru + mapPtr->head; 194 if (ru >= mapPtr->status_size) 195 ru = ru - mapPtr->status_size; 196 197 if ((ru < 0) || (ru >= mapPtr->status_size)) { 198 printf("raid%d: ru is bogus %" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "\n", 199 raidPtr->raidid, i, ru, mapPtr->head, mapPtr->low_ru, mapPtr->high_ru); 200 panic("bogus ru in reconmap"); 201 } 202 203 p = mapPtr->status[ru]; 204 if (p != RU_ALL) { 205 if (p == RU_NOTHING || p->startSector > startSector) { 206 /* insert at front of list */ 207 208 mapPtr->status[ru] = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), (p == RU_NOTHING) ? NULL : p); 209 210 } else {/* general case */ 211 do { /* search for place to insert */ 212 pt = p; 213 p = p->next; 214 } while (p && (p->startSector < startSector)); 215 pt->next = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), p); 216 217 } 218 compact_stat_entry(raidPtr, mapPtr, i, ru); 219 } 220 startSector = RF_MIN(stopSector, last_in_RU) + 1; 221 } 222 rf_lock_mutex2(mapPtr->mutex); 223 mapPtr->lock = 0; 224 rf_broadcast_cond2(mapPtr->cv); 225 rf_unlock_mutex2(mapPtr->mutex); 226 } 227 228 229 230 /*--------------------------------------------------------------------------- 231 * 232 * performs whatever list compactions can be done, and frees any space 233 * that is no longer necessary. Assumes only that the list is sorted 234 * by startSector. crunch_list() compacts a single list as much as 235 * possible, and the second block of code deletes the entire list if 236 * possible. crunch_list() is also called from 237 * MakeReconMapAccessList(). 238 * 239 * When a recon unit is detected to be fully reconstructed, we set the 240 * corresponding bit in the parity stripe map so that the head follow 241 * code will not select this parity stripe again. This is redundant 242 * (but harmless) when compact_stat_entry is called from the 243 * reconstruction code, but necessary when called from the user-write 244 * code. 245 * 246 *-------------------------------------------------------------------------*/ 247 248 static void 249 compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, int i, int j) 250 { 251 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 252 RF_ReconMapListElem_t *p = mapPtr->status[j]; 253 254 crunch_list(mapPtr, p); 255 256 if ((p->startSector == i * sectorsPerReconUnit) && 257 (p->stopSector == i * sectorsPerReconUnit + 258 sectorsPerReconUnit - 1)) { 259 mapPtr->status[j] = RU_ALL; 260 mapPtr->unitsLeft--; 261 FreeReconMapListElem(mapPtr, p); 262 } 263 } 264 265 266 static void 267 crunch_list(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *listPtr) 268 { 269 RF_ReconMapListElem_t *pt, *p = listPtr; 270 271 if (!p) 272 return; 273 pt = p; 274 p = p->next; 275 while (p) { 276 if (pt->stopSector >= p->startSector - 1) { 277 pt->stopSector = RF_MAX(pt->stopSector, p->stopSector); 278 pt->next = p->next; 279 FreeReconMapListElem(mapPtr, p); 280 p = pt->next; 281 } else { 282 pt = p; 283 p = p->next; 284 } 285 } 286 } 287 /*--------------------------------------------------------------------------- 288 * 289 * Allocate and fill a new list element 290 * 291 *-------------------------------------------------------------------------*/ 292 293 static RF_ReconMapListElem_t * 294 MakeReconMapListElem(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector, 295 RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next) 296 { 297 RF_ReconMapListElem_t *p; 298 299 p = pool_get(&mapPtr->elem_pool, PR_WAITOK); 300 p->startSector = startSector; 301 p->stopSector = stopSector; 302 p->next = next; 303 return (p); 304 } 305 /*--------------------------------------------------------------------------- 306 * 307 * Free a list element 308 * 309 *-------------------------------------------------------------------------*/ 310 311 static void 312 FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p) 313 { 314 pool_put(&mapPtr->elem_pool, p); 315 } 316 /*--------------------------------------------------------------------------- 317 * 318 * Free an entire status structure. Inefficient, but can be called at 319 * any time. 320 * 321 *-------------------------------------------------------------------------*/ 322 void 323 rf_FreeReconMap(RF_ReconMap_t *mapPtr) 324 { 325 RF_ReconMapListElem_t *p, *q; 326 RF_ReconUnitNum_t i; 327 328 for (i = 0; i < mapPtr->status_size; i++) { 329 p = mapPtr->status[i]; 330 while (p != RU_NOTHING && p != RU_ALL) { 331 q = p; 332 p = p->next; 333 RF_Free(q, sizeof(*q)); 334 } 335 } 336 337 rf_destroy_mutex2(mapPtr->mutex); 338 rf_destroy_cond2(mapPtr->cv); 339 340 pool_destroy(&mapPtr->elem_pool); 341 RF_Free(mapPtr->status, mapPtr->status_size * 342 sizeof(RF_ReconMapListElem_t *)); 343 RF_Free(mapPtr, sizeof(RF_ReconMap_t)); 344 } 345 /*--------------------------------------------------------------------------- 346 * 347 * returns nonzero if the indicated RU has been reconstructed already 348 * 349 *-------------------------------------------------------------------------*/ 350 351 int 352 rf_CheckRUReconstructed(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector) 353 { 354 RF_ReconUnitNum_t i; 355 int rv; 356 357 i = startSector / mapPtr->sectorsPerReconUnit; 358 359 if (i < mapPtr->low_ru) 360 rv = 1; 361 else if (i > mapPtr->high_ru) 362 rv = 0; 363 else { 364 i = i - mapPtr->low_ru + mapPtr->head; 365 if (i >= mapPtr->status_size) 366 i = i - mapPtr->status_size; 367 if (mapPtr->status[i] == RU_ALL) 368 rv = 1; 369 else 370 rv = 0; 371 } 372 373 return rv; 374 } 375 376 RF_ReconUnitCount_t 377 rf_UnitsLeftToReconstruct(RF_ReconMap_t *mapPtr) 378 { 379 RF_ASSERT(mapPtr != NULL); 380 return (mapPtr->unitsLeft); 381 } 382 383 #if RF_DEBUG_RECON 384 void 385 rf_PrintReconSchedule(RF_ReconMap_t *mapPtr, struct timeval *starttime) 386 { 387 static int old_pctg = -1; 388 struct timeval tv, diff; 389 int new_pctg; 390 391 new_pctg = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 392 100 / mapPtr->totalRUs); 393 if (new_pctg != old_pctg) { 394 RF_GETTIME(tv); 395 RF_TIMEVAL_DIFF(starttime, &tv, &diff); 396 printf("%d %d.%06d\n", (int) new_pctg, (int) diff.tv_sec, 397 (int) diff.tv_usec); 398 old_pctg = new_pctg; 399 } 400 } 401 #endif 402 403