1/* $NetBSD: rf_reconmap.c,v 1.39 2022/04/08 10:27:04 andvar 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 1.39 2022/04/08 10:27:04 andvar 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 63static void 64compact_stat_entry(RF_Raid_t *, RF_ReconMap_t *, int, int); 65static void crunch_list(RF_ReconMap_t *, RF_ReconMapListElem_t *); 66static RF_ReconMapListElem_t * 67MakeReconMapListElem(RF_ReconMap_t *, RF_SectorNum_t, RF_SectorNum_t, 68 RF_ReconMapListElem_t *); 69static void 70FreeReconMapListElem(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 81RF_ReconMap_t * 82rf_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 p = RF_Malloc(sizeof(*p)); 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 p->status = RF_Malloc(p->status_size * sizeof(*p->status)); 103 RF_ASSERT(p->status != NULL); 104 105 pool_init(&p->elem_pool, sizeof(RF_ReconMapListElem_t), 0, 106 0, 0, "raidreconpl", NULL, IPL_BIO); 107 pool_prime(&p->elem_pool, RF_NUM_RECON_POOL_ELEM); 108 109 rf_init_mutex2(p->mutex, IPL_VM); 110 rf_init_cond2(p->cv, "reconupdate"); 111 112 return (p); 113} 114 115 116/*--------------------------------------------------------------------------- 117 * 118 * marks a new set of sectors as reconstructed. All the possible 119 * mergings get complicated. To simplify matters, the approach I take 120 * is to just dump something into the list, and then clean it up 121 * (i.e. merge elements and eliminate redundant ones) in a second pass 122 * over the list (compact_stat_entry()). Not 100% efficient, since a 123 * structure can be allocated and then immediately freed, but it keeps 124 * this code from becoming (more of) a nightmare of special cases. 125 * The only thing that compact_stat_entry() assumes is that the list 126 * is sorted by startSector, and so this is the only condition I 127 * maintain here. (MCH) 128 * 129 * This code now uses a pool instead of the previous malloc/free 130 * stuff. 131 *-------------------------------------------------------------------------*/ 132 133void 134rf_ReconMapUpdate(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, 135 RF_SectorNum_t startSector, RF_SectorNum_t stopSector) 136{ 137 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 138 RF_SectorNum_t i, first_in_RU, last_in_RU, ru; 139 RF_ReconMapListElem_t *p, *pt; 140 141 rf_lock_mutex2(mapPtr->mutex); 142 while(mapPtr->lock) { 143 rf_wait_cond2(mapPtr->cv, mapPtr->mutex); 144 } 145 mapPtr->lock = 1; 146 rf_unlock_mutex2(mapPtr->mutex); 147 RF_ASSERT(startSector >= 0 && stopSector < mapPtr->sectorsInDisk && 148 stopSector >= startSector); 149 150 while (startSector <= stopSector) { 151 i = startSector / mapPtr->sectorsPerReconUnit; 152 first_in_RU = i * sectorsPerReconUnit; 153 last_in_RU = first_in_RU + sectorsPerReconUnit - 1; 154 155 /* do we need to move the queue? */ 156 while (i > mapPtr->high_ru) { 157#if 0 158#ifdef DIAGNOSTIC 159 /* XXX: The check below is not valid for 160 * RAID5_RS. It is valid for RAID 1 and RAID 5. 161 * The issue is that we can easily have 162 * RU_NOTHING entries here too, and those are 163 * quite correct. 164 */ 165 if (mapPtr->status[mapPtr->head]!=RU_ALL) { 166 printf("\nraid%d: reconmap incorrect -- working on i %" PRIu64 "\n", 167 raidPtr->raidid, i); 168 printf("raid%d: ru %" PRIu64 " not completed!!!\n", 169 raidPtr->raidid, mapPtr->head); 170 171 printf("raid%d: low: %" PRIu64 " high: %" PRIu64 "\n", 172 raidPtr->raidid, mapPtr->low_ru, mapPtr->high_ru); 173 174 panic("reconmap incorrect"); 175 } 176#endif 177#endif 178 mapPtr->low_ru++; 179 mapPtr->high_ru++; 180 /* initialize "highest" RU status entry, which 181 will take over the current head position */ 182 mapPtr->status[mapPtr->head]=RU_NOTHING; 183 184 /* move head too */ 185 mapPtr->head++; 186 if (mapPtr->head >= mapPtr->status_size) 187 mapPtr->head = 0; 188 189 } 190 191 ru = i - mapPtr->low_ru + mapPtr->head; 192 if (ru >= mapPtr->status_size) 193 ru = ru - mapPtr->status_size; 194 195 if ((ru < 0) || (ru >= mapPtr->status_size)) { 196 printf("raid%d: ru is bogus %" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "%" PRIu64 "\n", 197 raidPtr->raidid, i, ru, mapPtr->head, mapPtr->low_ru, mapPtr->high_ru); 198 panic("bogus ru in reconmap"); 199 } 200 201 p = mapPtr->status[ru]; 202 if (p != RU_ALL) { 203 if (p == RU_NOTHING || p->startSector > startSector) { 204 /* insert at front of list */ 205 206 mapPtr->status[ru] = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), (p == RU_NOTHING) ? NULL : p); 207 208 } else {/* general case */ 209 do { /* search for place to insert */ 210 pt = p; 211 p = p->next; 212 } while (p && (p->startSector < startSector)); 213 pt->next = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), p); 214 215 } 216 compact_stat_entry(raidPtr, mapPtr, i, ru); 217 } 218 startSector = RF_MIN(stopSector, last_in_RU) + 1; 219 } 220 rf_lock_mutex2(mapPtr->mutex); 221 mapPtr->lock = 0; 222 rf_broadcast_cond2(mapPtr->cv); 223 rf_unlock_mutex2(mapPtr->mutex); 224} 225 226 227 228/*--------------------------------------------------------------------------- 229 * 230 * performs whatever list compactions can be done, and frees any space 231 * that is no longer necessary. Assumes only that the list is sorted 232 * by startSector. crunch_list() compacts a single list as much as 233 * possible, and the second block of code deletes the entire list if 234 * possible. crunch_list() is also called from 235 * MakeReconMapAccessList(). 236 * 237 * When a recon unit is detected to be fully reconstructed, we set the 238 * corresponding bit in the parity stripe map so that the head follow 239 * code will not select this parity stripe again. This is redundant 240 * (but harmless) when compact_stat_entry is called from the 241 * reconstruction code, but necessary when called from the user-write 242 * code. 243 * 244 *-------------------------------------------------------------------------*/ 245 246static void 247compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, int i, int j) 248{ 249 RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit; 250 RF_ReconMapListElem_t *p = mapPtr->status[j]; 251 252 crunch_list(mapPtr, p); 253 254 if ((p->startSector == i * sectorsPerReconUnit) && 255 (p->stopSector == i * sectorsPerReconUnit + 256 sectorsPerReconUnit - 1)) { 257 mapPtr->status[j] = RU_ALL; 258 mapPtr->unitsLeft--; 259 FreeReconMapListElem(mapPtr, p); 260 } 261} 262 263 264static void 265crunch_list(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *listPtr) 266{ 267 RF_ReconMapListElem_t *pt, *p = listPtr; 268 269 if (!p) 270 return; 271 pt = p; 272 p = p->next; 273 while (p) { 274 if (pt->stopSector >= p->startSector - 1) { 275 pt->stopSector = RF_MAX(pt->stopSector, p->stopSector); 276 pt->next = p->next; 277 FreeReconMapListElem(mapPtr, p); 278 p = pt->next; 279 } else { 280 pt = p; 281 p = p->next; 282 } 283 } 284} 285/*--------------------------------------------------------------------------- 286 * 287 * Allocate and fill a new list element 288 * 289 *-------------------------------------------------------------------------*/ 290 291static RF_ReconMapListElem_t * 292MakeReconMapListElem(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector, 293 RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next) 294{ 295 RF_ReconMapListElem_t *p; 296 297 p = pool_get(&mapPtr->elem_pool, PR_WAITOK); 298 p->startSector = startSector; 299 p->stopSector = stopSector; 300 p->next = next; 301 return (p); 302} 303/*--------------------------------------------------------------------------- 304 * 305 * Free a list element 306 * 307 *-------------------------------------------------------------------------*/ 308 309static void 310FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p) 311{ 312 pool_put(&mapPtr->elem_pool, p); 313} 314/*--------------------------------------------------------------------------- 315 * 316 * Free an entire status structure. Inefficient, but can be called at 317 * any time. 318 * 319 *-------------------------------------------------------------------------*/ 320void 321rf_FreeReconMap(RF_ReconMap_t *mapPtr) 322{ 323 RF_ReconMapListElem_t *p, *q; 324 RF_ReconUnitNum_t i; 325 326 for (i = 0; i < mapPtr->status_size; i++) { 327 p = mapPtr->status[i]; 328 while (p != RU_NOTHING && p != RU_ALL) { 329 q = p; 330 p = p->next; 331 RF_Free(q, sizeof(*q)); 332 } 333 } 334 335 rf_destroy_mutex2(mapPtr->mutex); 336 rf_destroy_cond2(mapPtr->cv); 337 338 pool_destroy(&mapPtr->elem_pool); 339 RF_Free(mapPtr->status, mapPtr->status_size * 340 sizeof(RF_ReconMapListElem_t *)); 341 RF_Free(mapPtr, sizeof(RF_ReconMap_t)); 342} 343/*--------------------------------------------------------------------------- 344 * 345 * returns nonzero if the indicated RU has been reconstructed already 346 * 347 *-------------------------------------------------------------------------*/ 348 349int 350rf_CheckRUReconstructed(RF_ReconMap_t *mapPtr, RF_SectorNum_t startSector) 351{ 352 RF_ReconUnitNum_t i; 353 int rv; 354 355 i = startSector / mapPtr->sectorsPerReconUnit; 356 357 if (i < mapPtr->low_ru) 358 rv = 1; 359 else if (i > mapPtr->high_ru) 360 rv = 0; 361 else { 362 i = i - mapPtr->low_ru + mapPtr->head; 363 if (i >= mapPtr->status_size) 364 i = i - mapPtr->status_size; 365 if (mapPtr->status[i] == RU_ALL) 366 rv = 1; 367 else 368 rv = 0; 369 } 370 371 return rv; 372} 373 374RF_ReconUnitCount_t 375rf_UnitsLeftToReconstruct(RF_ReconMap_t *mapPtr) 376{ 377 RF_ASSERT(mapPtr != NULL); 378 return (mapPtr->unitsLeft); 379} 380 381#if RF_DEBUG_RECON 382void 383rf_PrintReconSchedule(RF_ReconMap_t *mapPtr, struct timeval *starttime) 384{ 385 static int old_pctg = -1; 386 struct timeval tv, diff; 387 int new_pctg; 388 389 new_pctg = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 390 100 / mapPtr->totalRUs); 391 if (new_pctg != old_pctg) { 392 RF_GETTIME(tv); 393 RF_TIMEVAL_DIFF(starttime, &tv, &diff); 394 printf("%d %d.%06d\n", (int) new_pctg, (int) diff.tv_sec, 395 (int) diff.tv_usec); 396 old_pctg = new_pctg; 397 } 398} 399#endif 400