1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/spa.h> 30 #include <sys/spa_impl.h> 31 #include <sys/zap.h> 32 #include <sys/dsl_synctask.h> 33 #include <sys/dmu_tx.h> 34 #include <sys/dmu_objset.h> 35 #include <sys/utsname.h> 36 #include <sys/cmn_err.h> 37 #include <sys/sunddi.h> 38 #ifdef _KERNEL 39 #include <sys/zone.h> 40 #endif 41 42 /* 43 * Routines to manage the on-disk history log. 44 * 45 * The history log is stored as a dmu object containing 46 * <packed record length, record nvlist> tuples. 47 * 48 * Where "record nvlist" is a nvlist containing uint64_ts and strings, and 49 * "packed record length" is the packed length of the "record nvlist" stored 50 * as a little endian uint64_t. 51 * 52 * The log is implemented as a ring buffer, though the original creation 53 * of the pool ('zpool create') is never overwritten. 54 * 55 * The history log is tracked as object 'spa_t::spa_history'. The bonus buffer 56 * of 'spa_history' stores the offsets for logging/retrieving history as 57 * 'spa_history_phys_t'. 'sh_pool_create_len' is the ending offset in bytes of 58 * where the 'zpool create' record is stored. This allows us to never 59 * overwrite the original creation of the pool. 'sh_phys_max_off' is the 60 * physical ending offset in bytes of the log. This tells you the length of 61 * the buffer. 'sh_eof' is the logical EOF (in bytes). Whenever a record 62 * is added, 'sh_eof' is incremented by the the size of the record. 63 * 'sh_eof' is never decremented. 'sh_bof' is the logical BOF (in bytes). 64 * This is where the consumer should start reading from after reading in 65 * the 'zpool create' portion of the log. 66 * 67 * 'sh_records_lost' keeps track of how many records have been overwritten 68 * and permanently lost. 69 */ 70 71 /* convert a logical offset to physical */ 72 static uint64_t 73 spa_history_log_to_phys(uint64_t log_off, spa_history_phys_t *shpp) 74 { 75 uint64_t phys_len; 76 77 phys_len = shpp->sh_phys_max_off - shpp->sh_pool_create_len; 78 return ((log_off - shpp->sh_pool_create_len) % phys_len 79 + shpp->sh_pool_create_len); 80 } 81 82 void 83 spa_history_create_obj(spa_t *spa, dmu_tx_t *tx) 84 { 85 dmu_buf_t *dbp; 86 spa_history_phys_t *shpp; 87 objset_t *mos = spa->spa_meta_objset; 88 89 ASSERT(spa->spa_history == 0); 90 spa->spa_history = dmu_object_alloc(mos, DMU_OT_SPA_HISTORY, 91 SPA_MAXBLOCKSIZE, DMU_OT_SPA_HISTORY_OFFSETS, 92 sizeof (spa_history_phys_t), tx); 93 94 VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT, 95 DMU_POOL_HISTORY, sizeof (uint64_t), 1, 96 &spa->spa_history, tx) == 0); 97 98 VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp)); 99 ASSERT(dbp->db_size >= sizeof (spa_history_phys_t)); 100 101 shpp = dbp->db_data; 102 dmu_buf_will_dirty(dbp, tx); 103 104 /* 105 * Figure out maximum size of history log. We set it at 106 * 1% of pool size, with a max of 32MB and min of 128KB. 107 */ 108 shpp->sh_phys_max_off = spa_get_dspace(spa) / 100; 109 shpp->sh_phys_max_off = MIN(shpp->sh_phys_max_off, 32<<20); 110 shpp->sh_phys_max_off = MAX(shpp->sh_phys_max_off, 128<<10); 111 112 dmu_buf_rele(dbp, FTAG); 113 } 114 115 /* 116 * Change 'sh_bof' to the beginning of the next record. 117 */ 118 static int 119 spa_history_advance_bof(spa_t *spa, spa_history_phys_t *shpp) 120 { 121 objset_t *mos = spa->spa_meta_objset; 122 uint64_t firstread, reclen, phys_bof; 123 char buf[sizeof (reclen)]; 124 int err; 125 126 phys_bof = spa_history_log_to_phys(shpp->sh_bof, shpp); 127 firstread = MIN(sizeof (reclen), shpp->sh_phys_max_off - phys_bof); 128 129 if ((err = dmu_read(mos, spa->spa_history, phys_bof, firstread, 130 buf)) != 0) 131 return (err); 132 if (firstread != sizeof (reclen)) { 133 if ((err = dmu_read(mos, spa->spa_history, 134 shpp->sh_pool_create_len, sizeof (reclen) - firstread, 135 buf + firstread)) != 0) 136 return (err); 137 } 138 139 reclen = LE_64(*((uint64_t *)buf)); 140 shpp->sh_bof += reclen + sizeof (reclen); 141 shpp->sh_records_lost++; 142 return (0); 143 } 144 145 static int 146 spa_history_write(spa_t *spa, void *buf, uint64_t len, spa_history_phys_t *shpp, 147 dmu_tx_t *tx) 148 { 149 uint64_t firstwrite, phys_eof; 150 objset_t *mos = spa->spa_meta_objset; 151 int err; 152 153 ASSERT(MUTEX_HELD(&spa->spa_history_lock)); 154 155 /* see if we need to reset logical BOF */ 156 while (shpp->sh_phys_max_off - shpp->sh_pool_create_len - 157 (shpp->sh_eof - shpp->sh_bof) <= len) { 158 if ((err = spa_history_advance_bof(spa, shpp)) != 0) { 159 return (err); 160 } 161 } 162 163 phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp); 164 firstwrite = MIN(len, shpp->sh_phys_max_off - phys_eof); 165 shpp->sh_eof += len; 166 dmu_write(mos, spa->spa_history, phys_eof, firstwrite, buf, tx); 167 168 len -= firstwrite; 169 if (len > 0) { 170 /* write out the rest at the beginning of physical file */ 171 dmu_write(mos, spa->spa_history, shpp->sh_pool_create_len, 172 len, (char *)buf + firstwrite, tx); 173 } 174 175 return (0); 176 } 177 178 static char * 179 spa_history_zone() 180 { 181 #ifdef _KERNEL 182 return (curproc->p_zone->zone_name); 183 #else 184 return ("global"); 185 #endif 186 } 187 188 /* 189 * Write out a history event. 190 */ 191 static void 192 spa_history_log_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 193 { 194 spa_t *spa = arg1; 195 history_arg_t *hap = arg2; 196 const char *history_str = hap->ha_history_str; 197 objset_t *mos = spa->spa_meta_objset; 198 dmu_buf_t *dbp; 199 spa_history_phys_t *shpp; 200 size_t reclen; 201 uint64_t le_len; 202 nvlist_t *nvrecord; 203 char *record_packed = NULL; 204 int ret; 205 206 /* 207 * If we have an older pool that doesn't have a command 208 * history object, create it now. 209 */ 210 mutex_enter(&spa->spa_history_lock); 211 if (!spa->spa_history) 212 spa_history_create_obj(spa, tx); 213 mutex_exit(&spa->spa_history_lock); 214 215 /* 216 * Get the offset of where we need to write via the bonus buffer. 217 * Update the offset when the write completes. 218 */ 219 VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp)); 220 shpp = dbp->db_data; 221 222 dmu_buf_will_dirty(dbp, tx); 223 224 #ifdef ZFS_DEBUG 225 { 226 dmu_object_info_t doi; 227 dmu_object_info_from_db(dbp, &doi); 228 ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS); 229 } 230 #endif 231 232 VERIFY(nvlist_alloc(&nvrecord, NV_UNIQUE_NAME, KM_SLEEP) == 0); 233 VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_TIME, 234 gethrestime_sec()) == 0); 235 VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_WHO, 236 (uint64_t)crgetuid(cr)) == 0); 237 if (hap->ha_zone[0] != '\0') 238 VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_ZONE, 239 hap->ha_zone) == 0); 240 #ifdef _KERNEL 241 VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_HOST, 242 utsname.nodename) == 0); 243 #endif 244 if (hap->ha_log_type == LOG_CMD_POOL_CREATE || 245 hap->ha_log_type == LOG_CMD_NORMAL) { 246 VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_CMD, 247 history_str) == 0); 248 } else { 249 VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_INT_EVENT, 250 hap->ha_event) == 0); 251 VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_TXG, 252 tx->tx_txg) == 0); 253 VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_INT_STR, 254 history_str) == 0); 255 } 256 257 VERIFY(nvlist_size(nvrecord, &reclen, NV_ENCODE_XDR) == 0); 258 record_packed = kmem_alloc(reclen, KM_SLEEP); 259 260 VERIFY(nvlist_pack(nvrecord, &record_packed, &reclen, 261 NV_ENCODE_XDR, KM_SLEEP) == 0); 262 263 mutex_enter(&spa->spa_history_lock); 264 if (hap->ha_log_type == LOG_CMD_POOL_CREATE) 265 VERIFY(shpp->sh_eof == shpp->sh_pool_create_len); 266 267 /* write out the packed length as little endian */ 268 le_len = LE_64((uint64_t)reclen); 269 ret = spa_history_write(spa, &le_len, sizeof (le_len), shpp, tx); 270 if (!ret) 271 ret = spa_history_write(spa, record_packed, reclen, shpp, tx); 272 273 if (!ret && hap->ha_log_type == LOG_CMD_POOL_CREATE) { 274 shpp->sh_pool_create_len += sizeof (le_len) + reclen; 275 shpp->sh_bof = shpp->sh_pool_create_len; 276 } 277 278 mutex_exit(&spa->spa_history_lock); 279 nvlist_free(nvrecord); 280 kmem_free(record_packed, reclen); 281 dmu_buf_rele(dbp, FTAG); 282 283 if (hap->ha_log_type == LOG_INTERNAL) { 284 kmem_free((void*)hap->ha_history_str, HIS_MAX_RECORD_LEN); 285 kmem_free(hap, sizeof (history_arg_t)); 286 } 287 } 288 289 /* 290 * Write out a history event. 291 */ 292 int 293 spa_history_log(spa_t *spa, const char *history_str, history_log_type_t what) 294 { 295 history_arg_t ha; 296 297 ASSERT(what != LOG_INTERNAL); 298 299 ha.ha_history_str = history_str; 300 ha.ha_log_type = what; 301 (void) strlcpy(ha.ha_zone, spa_history_zone(), sizeof (ha.ha_zone)); 302 return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_history_log_sync, 303 spa, &ha, 0)); 304 } 305 306 /* 307 * Read out the command history. 308 */ 309 int 310 spa_history_get(spa_t *spa, uint64_t *offp, uint64_t *len, char *buf) 311 { 312 objset_t *mos = spa->spa_meta_objset; 313 dmu_buf_t *dbp; 314 uint64_t read_len, phys_read_off, phys_eof; 315 uint64_t leftover = 0; 316 spa_history_phys_t *shpp; 317 int err; 318 319 /* 320 * If the command history doesn't exist (older pool), 321 * that's ok, just return ENOENT. 322 */ 323 if (!spa->spa_history) 324 return (ENOENT); 325 326 if ((err = dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp)) != 0) 327 return (err); 328 shpp = dbp->db_data; 329 330 #ifdef ZFS_DEBUG 331 { 332 dmu_object_info_t doi; 333 dmu_object_info_from_db(dbp, &doi); 334 ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS); 335 } 336 #endif 337 338 mutex_enter(&spa->spa_history_lock); 339 phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp); 340 341 if (*offp < shpp->sh_pool_create_len) { 342 /* read in just the zpool create history */ 343 phys_read_off = *offp; 344 read_len = MIN(*len, shpp->sh_pool_create_len - 345 phys_read_off); 346 } else { 347 /* 348 * Need to reset passed in offset to BOF if the passed in 349 * offset has since been overwritten. 350 */ 351 *offp = MAX(*offp, shpp->sh_bof); 352 phys_read_off = spa_history_log_to_phys(*offp, shpp); 353 354 /* 355 * Read up to the minimum of what the user passed down or 356 * the EOF (physical or logical). If we hit physical EOF, 357 * use 'leftover' to read from the physical BOF. 358 */ 359 if (phys_read_off <= phys_eof) { 360 read_len = MIN(*len, phys_eof - phys_read_off); 361 } else { 362 read_len = MIN(*len, 363 shpp->sh_phys_max_off - phys_read_off); 364 if (phys_read_off + *len > shpp->sh_phys_max_off) { 365 leftover = MIN(*len - read_len, 366 phys_eof - shpp->sh_pool_create_len); 367 } 368 } 369 } 370 371 /* offset for consumer to use next */ 372 *offp += read_len + leftover; 373 374 /* tell the consumer how much you actually read */ 375 *len = read_len + leftover; 376 377 if (read_len == 0) { 378 mutex_exit(&spa->spa_history_lock); 379 dmu_buf_rele(dbp, FTAG); 380 return (0); 381 } 382 383 err = dmu_read(mos, spa->spa_history, phys_read_off, read_len, buf); 384 if (leftover && err == 0) { 385 err = dmu_read(mos, spa->spa_history, shpp->sh_pool_create_len, 386 leftover, buf + read_len); 387 } 388 mutex_exit(&spa->spa_history_lock); 389 390 dmu_buf_rele(dbp, FTAG); 391 return (err); 392 } 393 394 void 395 spa_history_internal_log(history_internal_events_t event, spa_t *spa, 396 dmu_tx_t *tx, cred_t *cr, const char *fmt, ...) 397 { 398 history_arg_t *hap; 399 char *str; 400 va_list adx; 401 402 /* 403 * If this is part of creating a pool, not everything is 404 * initialized yet, so don't bother logging the internal events. 405 */ 406 if (tx->tx_txg == TXG_INITIAL) 407 return; 408 409 hap = kmem_alloc(sizeof (history_arg_t), KM_SLEEP); 410 str = kmem_alloc(HIS_MAX_RECORD_LEN, KM_SLEEP); 411 412 va_start(adx, fmt); 413 (void) vsnprintf(str, HIS_MAX_RECORD_LEN, fmt, adx); 414 va_end(adx); 415 416 hap->ha_log_type = LOG_INTERNAL; 417 hap->ha_history_str = str; 418 hap->ha_event = event; 419 hap->ha_zone[0] = '\0'; 420 421 if (dmu_tx_is_syncing(tx)) { 422 spa_history_log_sync(spa, hap, cr, tx); 423 } else { 424 dsl_sync_task_do_nowait(spa_get_dsl(spa), NULL, 425 spa_history_log_sync, spa, hap, 0, tx); 426 } 427 /* spa_history_log_sync() will free hap and str */ 428 } 429