1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include "xfs_fs.h" 8 #include "xfs_shared.h" 9 #include "xfs_format.h" 10 #include "xfs_log_format.h" 11 #include "xfs_trans_resv.h" 12 #include "xfs_sb.h" 13 #include "xfs_mount.h" 14 #include "xfs_trans.h" 15 #include "xfs_error.h" 16 #include "xfs_alloc.h" 17 #include "xfs_fsops.h" 18 #include "xfs_trans_space.h" 19 #include "xfs_log.h" 20 #include "xfs_log_priv.h" 21 #include "xfs_ag.h" 22 #include "xfs_ag_resv.h" 23 #include "xfs_trace.h" 24 25 /* 26 * Write new AG headers to disk. Non-transactional, but need to be 27 * written and completed prior to the growfs transaction being logged. 28 * To do this, we use a delayed write buffer list and wait for 29 * submission and IO completion of the list as a whole. This allows the 30 * IO subsystem to merge all the AG headers in a single AG into a single 31 * IO and hide most of the latency of the IO from us. 32 * 33 * This also means that if we get an error whilst building the buffer 34 * list to write, we can cancel the entire list without having written 35 * anything. 36 */ 37 static int 38 xfs_resizefs_init_new_ags( 39 struct xfs_trans *tp, 40 struct aghdr_init_data *id, 41 xfs_agnumber_t oagcount, 42 xfs_agnumber_t nagcount, 43 xfs_rfsblock_t delta, 44 struct xfs_perag *last_pag, 45 bool *lastag_extended) 46 { 47 struct xfs_mount *mp = tp->t_mountp; 48 xfs_rfsblock_t nb = mp->m_sb.sb_dblocks + delta; 49 int error; 50 51 *lastag_extended = false; 52 53 INIT_LIST_HEAD(&id->buffer_list); 54 for (id->agno = nagcount - 1; 55 id->agno >= oagcount; 56 id->agno--, delta -= id->agsize) { 57 58 if (id->agno == nagcount - 1) 59 id->agsize = nb - (id->agno * 60 (xfs_rfsblock_t)mp->m_sb.sb_agblocks); 61 else 62 id->agsize = mp->m_sb.sb_agblocks; 63 64 error = xfs_ag_init_headers(mp, id); 65 if (error) { 66 xfs_buf_delwri_cancel(&id->buffer_list); 67 return error; 68 } 69 } 70 71 error = xfs_buf_delwri_submit(&id->buffer_list); 72 if (error) 73 return error; 74 75 if (delta) { 76 *lastag_extended = true; 77 error = xfs_ag_extend_space(last_pag, tp, delta); 78 } 79 return error; 80 } 81 82 /* 83 * growfs operations 84 */ 85 static int 86 xfs_growfs_data_private( 87 struct xfs_mount *mp, /* mount point for filesystem */ 88 struct xfs_growfs_data *in) /* growfs data input struct */ 89 { 90 xfs_agnumber_t oagcount = mp->m_sb.sb_agcount; 91 struct xfs_buf *bp; 92 int error; 93 xfs_agnumber_t nagcount; 94 xfs_agnumber_t nagimax = 0; 95 xfs_rfsblock_t nb, nb_div, nb_mod; 96 int64_t delta; 97 bool lastag_extended = false; 98 struct xfs_trans *tp; 99 struct aghdr_init_data id = {}; 100 struct xfs_perag *last_pag; 101 102 nb = in->newblocks; 103 error = xfs_sb_validate_fsb_count(&mp->m_sb, nb); 104 if (error) 105 return error; 106 107 if (nb > mp->m_sb.sb_dblocks) { 108 error = xfs_buf_read_uncached(mp->m_ddev_targp, 109 XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1), 110 XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL); 111 if (error) 112 return error; 113 xfs_buf_relse(bp); 114 } 115 116 nb_div = nb; 117 nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks); 118 if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS) 119 nb_div++; 120 else if (nb_mod) 121 nb = nb_div * mp->m_sb.sb_agblocks; 122 123 if (nb_div > XFS_MAX_AGNUMBER + 1) { 124 nb_div = XFS_MAX_AGNUMBER + 1; 125 nb = nb_div * mp->m_sb.sb_agblocks; 126 } 127 nagcount = nb_div; 128 delta = nb - mp->m_sb.sb_dblocks; 129 /* 130 * Reject filesystems with a single AG because they are not 131 * supported, and reject a shrink operation that would cause a 132 * filesystem to become unsupported. 133 */ 134 if (delta < 0 && nagcount < 2) 135 return -EINVAL; 136 137 /* No work to do */ 138 if (delta == 0) 139 return 0; 140 141 /* TODO: shrinking the entire AGs hasn't yet completed */ 142 if (nagcount < oagcount) 143 return -EINVAL; 144 145 /* allocate the new per-ag structures */ 146 error = xfs_initialize_perag(mp, oagcount, nagcount, nb, &nagimax); 147 if (error) 148 return error; 149 150 if (delta > 0) 151 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, 152 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, 153 &tp); 154 else 155 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, -delta, 0, 156 0, &tp); 157 if (error) 158 goto out_free_unused_perag; 159 160 last_pag = xfs_perag_get(mp, oagcount - 1); 161 if (delta > 0) { 162 error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount, 163 delta, last_pag, &lastag_extended); 164 } else { 165 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_SHRINK, 166 "EXPERIMENTAL online shrink feature in use. Use at your own risk!"); 167 168 error = xfs_ag_shrink_space(last_pag, &tp, -delta); 169 } 170 xfs_perag_put(last_pag); 171 if (error) 172 goto out_trans_cancel; 173 174 /* 175 * Update changed superblock fields transactionally. These are not 176 * seen by the rest of the world until the transaction commit applies 177 * them atomically to the superblock. 178 */ 179 if (nagcount > oagcount) 180 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount); 181 if (delta) 182 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta); 183 if (id.nfree) 184 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree); 185 186 /* 187 * Sync sb counters now to reflect the updated values. This is 188 * particularly important for shrink because the write verifier 189 * will fail if sb_fdblocks is ever larger than sb_dblocks. 190 */ 191 if (xfs_has_lazysbcount(mp)) 192 xfs_log_sb(tp); 193 194 xfs_trans_set_sync(tp); 195 error = xfs_trans_commit(tp); 196 if (error) 197 return error; 198 199 /* New allocation groups fully initialized, so update mount struct */ 200 if (nagimax) 201 mp->m_maxagi = nagimax; 202 xfs_set_low_space_thresholds(mp); 203 mp->m_alloc_set_aside = xfs_alloc_set_aside(mp); 204 205 if (delta > 0) { 206 /* 207 * If we expanded the last AG, free the per-AG reservation 208 * so we can reinitialize it with the new size. 209 */ 210 if (lastag_extended) { 211 struct xfs_perag *pag; 212 213 pag = xfs_perag_get(mp, id.agno); 214 xfs_ag_resv_free(pag); 215 xfs_perag_put(pag); 216 } 217 /* 218 * Reserve AG metadata blocks. ENOSPC here does not mean there 219 * was a growfs failure, just that there still isn't space for 220 * new user data after the grow has been run. 221 */ 222 error = xfs_fs_reserve_ag_blocks(mp); 223 if (error == -ENOSPC) 224 error = 0; 225 } 226 return error; 227 228 out_trans_cancel: 229 xfs_trans_cancel(tp); 230 out_free_unused_perag: 231 if (nagcount > oagcount) 232 xfs_free_perag_range(mp, oagcount, nagcount); 233 return error; 234 } 235 236 static int 237 xfs_growfs_log_private( 238 struct xfs_mount *mp, /* mount point for filesystem */ 239 struct xfs_growfs_log *in) /* growfs log input struct */ 240 { 241 xfs_extlen_t nb; 242 243 nb = in->newblocks; 244 if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES)) 245 return -EINVAL; 246 if (nb == mp->m_sb.sb_logblocks && 247 in->isint == (mp->m_sb.sb_logstart != 0)) 248 return -EINVAL; 249 /* 250 * Moving the log is hard, need new interfaces to sync 251 * the log first, hold off all activity while moving it. 252 * Can have shorter or longer log in the same space, 253 * or transform internal to external log or vice versa. 254 */ 255 return -ENOSYS; 256 } 257 258 static int 259 xfs_growfs_imaxpct( 260 struct xfs_mount *mp, 261 __u32 imaxpct) 262 { 263 struct xfs_trans *tp; 264 int dpct; 265 int error; 266 267 if (imaxpct > 100) 268 return -EINVAL; 269 270 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, 271 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp); 272 if (error) 273 return error; 274 275 dpct = imaxpct - mp->m_sb.sb_imax_pct; 276 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct); 277 xfs_trans_set_sync(tp); 278 return xfs_trans_commit(tp); 279 } 280 281 /* 282 * protected versions of growfs function acquire and release locks on the mount 283 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG, 284 * XFS_IOC_FSGROWFSRT 285 */ 286 int 287 xfs_growfs_data( 288 struct xfs_mount *mp, 289 struct xfs_growfs_data *in) 290 { 291 int error = 0; 292 293 if (!capable(CAP_SYS_ADMIN)) 294 return -EPERM; 295 if (!mutex_trylock(&mp->m_growlock)) 296 return -EWOULDBLOCK; 297 298 /* update imaxpct separately to the physical grow of the filesystem */ 299 if (in->imaxpct != mp->m_sb.sb_imax_pct) { 300 error = xfs_growfs_imaxpct(mp, in->imaxpct); 301 if (error) 302 goto out_error; 303 } 304 305 if (in->newblocks != mp->m_sb.sb_dblocks) { 306 error = xfs_growfs_data_private(mp, in); 307 if (error) 308 goto out_error; 309 } 310 311 /* Post growfs calculations needed to reflect new state in operations */ 312 if (mp->m_sb.sb_imax_pct) { 313 uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct; 314 do_div(icount, 100); 315 M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount); 316 } else 317 M_IGEO(mp)->maxicount = 0; 318 319 /* Update secondary superblocks now the physical grow has completed */ 320 error = xfs_update_secondary_sbs(mp); 321 322 out_error: 323 /* 324 * Increment the generation unconditionally, the error could be from 325 * updating the secondary superblocks, in which case the new size 326 * is live already. 327 */ 328 mp->m_generation++; 329 mutex_unlock(&mp->m_growlock); 330 return error; 331 } 332 333 int 334 xfs_growfs_log( 335 xfs_mount_t *mp, 336 struct xfs_growfs_log *in) 337 { 338 int error; 339 340 if (!capable(CAP_SYS_ADMIN)) 341 return -EPERM; 342 if (!mutex_trylock(&mp->m_growlock)) 343 return -EWOULDBLOCK; 344 error = xfs_growfs_log_private(mp, in); 345 mutex_unlock(&mp->m_growlock); 346 return error; 347 } 348 349 /* 350 * Reserve the requested number of blocks if available. Otherwise return 351 * as many as possible to satisfy the request. The actual number 352 * reserved are returned in outval. 353 */ 354 int 355 xfs_reserve_blocks( 356 struct xfs_mount *mp, 357 uint64_t request) 358 { 359 int64_t lcounter, delta; 360 int64_t fdblks_delta = 0; 361 int64_t free; 362 int error = 0; 363 364 /* 365 * With per-cpu counters, this becomes an interesting problem. we need 366 * to work out if we are freeing or allocation blocks first, then we can 367 * do the modification as necessary. 368 * 369 * We do this under the m_sb_lock so that if we are near ENOSPC, we will 370 * hold out any changes while we work out what to do. This means that 371 * the amount of free space can change while we do this, so we need to 372 * retry if we end up trying to reserve more space than is available. 373 */ 374 spin_lock(&mp->m_sb_lock); 375 376 /* 377 * If our previous reservation was larger than the current value, 378 * then move any unused blocks back to the free pool. Modify the resblks 379 * counters directly since we shouldn't have any problems unreserving 380 * space. 381 */ 382 if (mp->m_resblks > request) { 383 lcounter = mp->m_resblks_avail - request; 384 if (lcounter > 0) { /* release unused blocks */ 385 fdblks_delta = lcounter; 386 mp->m_resblks_avail -= lcounter; 387 } 388 mp->m_resblks = request; 389 if (fdblks_delta) { 390 spin_unlock(&mp->m_sb_lock); 391 xfs_add_fdblocks(mp, fdblks_delta); 392 spin_lock(&mp->m_sb_lock); 393 } 394 395 goto out; 396 } 397 398 /* 399 * If the request is larger than the current reservation, reserve the 400 * blocks before we update the reserve counters. Sample m_fdblocks and 401 * perform a partial reservation if the request exceeds free space. 402 * 403 * The code below estimates how many blocks it can request from 404 * fdblocks to stash in the reserve pool. This is a classic TOCTOU 405 * race since fdblocks updates are not always coordinated via 406 * m_sb_lock. Set the reserve size even if there's not enough free 407 * space to fill it because mod_fdblocks will refill an undersized 408 * reserve when it can. 409 */ 410 free = percpu_counter_sum(&mp->m_fdblocks) - 411 xfs_fdblocks_unavailable(mp); 412 delta = request - mp->m_resblks; 413 mp->m_resblks = request; 414 if (delta > 0 && free > 0) { 415 /* 416 * We'll either succeed in getting space from the free block 417 * count or we'll get an ENOSPC. Don't set the reserved flag 418 * here - we don't want to reserve the extra reserve blocks 419 * from the reserve. 420 * 421 * The desired reserve size can change after we drop the lock. 422 * Use mod_fdblocks to put the space into the reserve or into 423 * fdblocks as appropriate. 424 */ 425 fdblks_delta = min(free, delta); 426 spin_unlock(&mp->m_sb_lock); 427 error = xfs_dec_fdblocks(mp, fdblks_delta, 0); 428 if (!error) 429 xfs_add_fdblocks(mp, fdblks_delta); 430 spin_lock(&mp->m_sb_lock); 431 } 432 out: 433 spin_unlock(&mp->m_sb_lock); 434 return error; 435 } 436 437 int 438 xfs_fs_goingdown( 439 xfs_mount_t *mp, 440 uint32_t inflags) 441 { 442 switch (inflags) { 443 case XFS_FSOP_GOING_FLAGS_DEFAULT: { 444 if (!bdev_freeze(mp->m_super->s_bdev)) { 445 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT); 446 bdev_thaw(mp->m_super->s_bdev); 447 } 448 break; 449 } 450 case XFS_FSOP_GOING_FLAGS_LOGFLUSH: 451 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT); 452 break; 453 case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH: 454 xfs_force_shutdown(mp, 455 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR); 456 break; 457 default: 458 return -EINVAL; 459 } 460 461 return 0; 462 } 463 464 /* 465 * Force a shutdown of the filesystem instantly while keeping the filesystem 466 * consistent. We don't do an unmount here; just shutdown the shop, make sure 467 * that absolutely nothing persistent happens to this filesystem after this 468 * point. 469 * 470 * The shutdown state change is atomic, resulting in the first and only the 471 * first shutdown call processing the shutdown. This means we only shutdown the 472 * log once as it requires, and we don't spam the logs when multiple concurrent 473 * shutdowns race to set the shutdown flags. 474 */ 475 void 476 xfs_do_force_shutdown( 477 struct xfs_mount *mp, 478 uint32_t flags, 479 char *fname, 480 int lnnum) 481 { 482 int tag; 483 const char *why; 484 485 486 if (xfs_set_shutdown(mp)) { 487 xlog_shutdown_wait(mp->m_log); 488 return; 489 } 490 if (mp->m_sb_bp) 491 mp->m_sb_bp->b_flags |= XBF_DONE; 492 493 if (flags & SHUTDOWN_FORCE_UMOUNT) 494 xfs_alert(mp, "User initiated shutdown received."); 495 496 if (xlog_force_shutdown(mp->m_log, flags)) { 497 tag = XFS_PTAG_SHUTDOWN_LOGERROR; 498 why = "Log I/O Error"; 499 } else if (flags & SHUTDOWN_CORRUPT_INCORE) { 500 tag = XFS_PTAG_SHUTDOWN_CORRUPT; 501 why = "Corruption of in-memory data"; 502 } else if (flags & SHUTDOWN_CORRUPT_ONDISK) { 503 tag = XFS_PTAG_SHUTDOWN_CORRUPT; 504 why = "Corruption of on-disk metadata"; 505 } else if (flags & SHUTDOWN_DEVICE_REMOVED) { 506 tag = XFS_PTAG_SHUTDOWN_IOERROR; 507 why = "Block device removal"; 508 } else { 509 tag = XFS_PTAG_SHUTDOWN_IOERROR; 510 why = "Metadata I/O Error"; 511 } 512 513 trace_xfs_force_shutdown(mp, tag, flags, fname, lnnum); 514 515 xfs_alert_tag(mp, tag, 516 "%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.", 517 why, flags, __return_address, fname, lnnum); 518 xfs_alert(mp, 519 "Please unmount the filesystem and rectify the problem(s)"); 520 if (xfs_error_level >= XFS_ERRLEVEL_HIGH) 521 xfs_stack_trace(); 522 } 523 524 /* 525 * Reserve free space for per-AG metadata. 526 */ 527 int 528 xfs_fs_reserve_ag_blocks( 529 struct xfs_mount *mp) 530 { 531 xfs_agnumber_t agno; 532 struct xfs_perag *pag; 533 int error = 0; 534 int err2; 535 536 mp->m_finobt_nores = false; 537 for_each_perag(mp, agno, pag) { 538 err2 = xfs_ag_resv_init(pag, NULL); 539 if (err2 && !error) 540 error = err2; 541 } 542 543 if (error && error != -ENOSPC) { 544 xfs_warn(mp, 545 "Error %d reserving per-AG metadata reserve pool.", error); 546 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); 547 } 548 549 return error; 550 } 551 552 /* 553 * Free space reserved for per-AG metadata. 554 */ 555 void 556 xfs_fs_unreserve_ag_blocks( 557 struct xfs_mount *mp) 558 { 559 xfs_agnumber_t agno; 560 struct xfs_perag *pag; 561 562 for_each_perag(mp, agno, pag) 563 xfs_ag_resv_free(pag); 564 } 565