repair.c (28474B)
1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Copyright (C) 2018 Oracle. All Rights Reserved. 4 * Author: Darrick J. Wong <darrick.wong@oracle.com> 5 */ 6#include "xfs.h" 7#include "xfs_fs.h" 8#include "xfs_shared.h" 9#include "xfs_format.h" 10#include "xfs_trans_resv.h" 11#include "xfs_mount.h" 12#include "xfs_btree.h" 13#include "xfs_log_format.h" 14#include "xfs_trans.h" 15#include "xfs_sb.h" 16#include "xfs_inode.h" 17#include "xfs_alloc.h" 18#include "xfs_alloc_btree.h" 19#include "xfs_ialloc.h" 20#include "xfs_ialloc_btree.h" 21#include "xfs_rmap.h" 22#include "xfs_rmap_btree.h" 23#include "xfs_refcount_btree.h" 24#include "xfs_extent_busy.h" 25#include "xfs_ag.h" 26#include "xfs_ag_resv.h" 27#include "xfs_quota.h" 28#include "xfs_qm.h" 29#include "scrub/scrub.h" 30#include "scrub/common.h" 31#include "scrub/trace.h" 32#include "scrub/repair.h" 33#include "scrub/bitmap.h" 34 35/* 36 * Attempt to repair some metadata, if the metadata is corrupt and userspace 37 * told us to fix it. This function returns -EAGAIN to mean "re-run scrub", 38 * and will set *fixed to true if it thinks it repaired anything. 39 */ 40int 41xrep_attempt( 42 struct xfs_scrub *sc) 43{ 44 int error = 0; 45 46 trace_xrep_attempt(XFS_I(file_inode(sc->file)), sc->sm, error); 47 48 xchk_ag_btcur_free(&sc->sa); 49 50 /* Repair whatever's broken. */ 51 ASSERT(sc->ops->repair); 52 error = sc->ops->repair(sc); 53 trace_xrep_done(XFS_I(file_inode(sc->file)), sc->sm, error); 54 switch (error) { 55 case 0: 56 /* 57 * Repair succeeded. Commit the fixes and perform a second 58 * scrub so that we can tell userspace if we fixed the problem. 59 */ 60 sc->sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT; 61 sc->flags |= XREP_ALREADY_FIXED; 62 return -EAGAIN; 63 case -EDEADLOCK: 64 case -EAGAIN: 65 /* Tell the caller to try again having grabbed all the locks. */ 66 if (!(sc->flags & XCHK_TRY_HARDER)) { 67 sc->flags |= XCHK_TRY_HARDER; 68 return -EAGAIN; 69 } 70 /* 71 * We tried harder but still couldn't grab all the resources 72 * we needed to fix it. The corruption has not been fixed, 73 * so report back to userspace. 74 */ 75 return -EFSCORRUPTED; 76 default: 77 return error; 78 } 79} 80 81/* 82 * Complain about unfixable problems in the filesystem. We don't log 83 * corruptions when IFLAG_REPAIR wasn't set on the assumption that the driver 84 * program is xfs_scrub, which will call back with IFLAG_REPAIR set if the 85 * administrator isn't running xfs_scrub in no-repairs mode. 86 * 87 * Use this helper function because _ratelimited silently declares a static 88 * structure to track rate limiting information. 89 */ 90void 91xrep_failure( 92 struct xfs_mount *mp) 93{ 94 xfs_alert_ratelimited(mp, 95"Corruption not fixed during online repair. Unmount and run xfs_repair."); 96} 97 98/* 99 * Repair probe -- userspace uses this to probe if we're willing to repair a 100 * given mountpoint. 101 */ 102int 103xrep_probe( 104 struct xfs_scrub *sc) 105{ 106 int error = 0; 107 108 if (xchk_should_terminate(sc, &error)) 109 return error; 110 111 return 0; 112} 113 114/* 115 * Roll a transaction, keeping the AG headers locked and reinitializing 116 * the btree cursors. 117 */ 118int 119xrep_roll_ag_trans( 120 struct xfs_scrub *sc) 121{ 122 int error; 123 124 /* Keep the AG header buffers locked so we can keep going. */ 125 if (sc->sa.agi_bp) 126 xfs_trans_bhold(sc->tp, sc->sa.agi_bp); 127 if (sc->sa.agf_bp) 128 xfs_trans_bhold(sc->tp, sc->sa.agf_bp); 129 if (sc->sa.agfl_bp) 130 xfs_trans_bhold(sc->tp, sc->sa.agfl_bp); 131 132 /* 133 * Roll the transaction. We still own the buffer and the buffer lock 134 * regardless of whether or not the roll succeeds. If the roll fails, 135 * the buffers will be released during teardown on our way out of the 136 * kernel. If it succeeds, we join them to the new transaction and 137 * move on. 138 */ 139 error = xfs_trans_roll(&sc->tp); 140 if (error) 141 return error; 142 143 /* Join AG headers to the new transaction. */ 144 if (sc->sa.agi_bp) 145 xfs_trans_bjoin(sc->tp, sc->sa.agi_bp); 146 if (sc->sa.agf_bp) 147 xfs_trans_bjoin(sc->tp, sc->sa.agf_bp); 148 if (sc->sa.agfl_bp) 149 xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp); 150 151 return 0; 152} 153 154/* 155 * Does the given AG have enough space to rebuild a btree? Neither AG 156 * reservation can be critical, and we must have enough space (factoring 157 * in AG reservations) to construct a whole btree. 158 */ 159bool 160xrep_ag_has_space( 161 struct xfs_perag *pag, 162 xfs_extlen_t nr_blocks, 163 enum xfs_ag_resv_type type) 164{ 165 return !xfs_ag_resv_critical(pag, XFS_AG_RESV_RMAPBT) && 166 !xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA) && 167 pag->pagf_freeblks > xfs_ag_resv_needed(pag, type) + nr_blocks; 168} 169 170/* 171 * Figure out how many blocks to reserve for an AG repair. We calculate the 172 * worst case estimate for the number of blocks we'd need to rebuild one of 173 * any type of per-AG btree. 174 */ 175xfs_extlen_t 176xrep_calc_ag_resblks( 177 struct xfs_scrub *sc) 178{ 179 struct xfs_mount *mp = sc->mp; 180 struct xfs_scrub_metadata *sm = sc->sm; 181 struct xfs_perag *pag; 182 struct xfs_buf *bp; 183 xfs_agino_t icount = NULLAGINO; 184 xfs_extlen_t aglen = NULLAGBLOCK; 185 xfs_extlen_t usedlen; 186 xfs_extlen_t freelen; 187 xfs_extlen_t bnobt_sz; 188 xfs_extlen_t inobt_sz; 189 xfs_extlen_t rmapbt_sz; 190 xfs_extlen_t refcbt_sz; 191 int error; 192 193 if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)) 194 return 0; 195 196 pag = xfs_perag_get(mp, sm->sm_agno); 197 if (pag->pagi_init) { 198 /* Use in-core icount if possible. */ 199 icount = pag->pagi_count; 200 } else { 201 /* Try to get the actual counters from disk. */ 202 error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp); 203 if (!error) { 204 icount = pag->pagi_count; 205 xfs_buf_relse(bp); 206 } 207 } 208 209 /* Now grab the block counters from the AGF. */ 210 error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp); 211 if (error) { 212 aglen = xfs_ag_block_count(mp, sm->sm_agno); 213 freelen = aglen; 214 usedlen = aglen; 215 } else { 216 struct xfs_agf *agf = bp->b_addr; 217 218 aglen = be32_to_cpu(agf->agf_length); 219 freelen = be32_to_cpu(agf->agf_freeblks); 220 usedlen = aglen - freelen; 221 xfs_buf_relse(bp); 222 } 223 xfs_perag_put(pag); 224 225 /* If the icount is impossible, make some worst-case assumptions. */ 226 if (icount == NULLAGINO || 227 !xfs_verify_agino(mp, sm->sm_agno, icount)) { 228 xfs_agino_t first, last; 229 230 xfs_agino_range(mp, sm->sm_agno, &first, &last); 231 icount = last - first + 1; 232 } 233 234 /* If the block counts are impossible, make worst-case assumptions. */ 235 if (aglen == NULLAGBLOCK || 236 aglen != xfs_ag_block_count(mp, sm->sm_agno) || 237 freelen >= aglen) { 238 aglen = xfs_ag_block_count(mp, sm->sm_agno); 239 freelen = aglen; 240 usedlen = aglen; 241 } 242 243 trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen, 244 freelen, usedlen); 245 246 /* 247 * Figure out how many blocks we'd need worst case to rebuild 248 * each type of btree. Note that we can only rebuild the 249 * bnobt/cntbt or inobt/finobt as pairs. 250 */ 251 bnobt_sz = 2 * xfs_allocbt_calc_size(mp, freelen); 252 if (xfs_has_sparseinodes(mp)) 253 inobt_sz = xfs_iallocbt_calc_size(mp, icount / 254 XFS_INODES_PER_HOLEMASK_BIT); 255 else 256 inobt_sz = xfs_iallocbt_calc_size(mp, icount / 257 XFS_INODES_PER_CHUNK); 258 if (xfs_has_finobt(mp)) 259 inobt_sz *= 2; 260 if (xfs_has_reflink(mp)) 261 refcbt_sz = xfs_refcountbt_calc_size(mp, usedlen); 262 else 263 refcbt_sz = 0; 264 if (xfs_has_rmapbt(mp)) { 265 /* 266 * Guess how many blocks we need to rebuild the rmapbt. 267 * For non-reflink filesystems we can't have more records than 268 * used blocks. However, with reflink it's possible to have 269 * more than one rmap record per AG block. We don't know how 270 * many rmaps there could be in the AG, so we start off with 271 * what we hope is an generous over-estimation. 272 */ 273 if (xfs_has_reflink(mp)) 274 rmapbt_sz = xfs_rmapbt_calc_size(mp, 275 (unsigned long long)aglen * 2); 276 else 277 rmapbt_sz = xfs_rmapbt_calc_size(mp, usedlen); 278 } else { 279 rmapbt_sz = 0; 280 } 281 282 trace_xrep_calc_ag_resblks_btsize(mp, sm->sm_agno, bnobt_sz, 283 inobt_sz, rmapbt_sz, refcbt_sz); 284 285 return max(max(bnobt_sz, inobt_sz), max(rmapbt_sz, refcbt_sz)); 286} 287 288/* Allocate a block in an AG. */ 289int 290xrep_alloc_ag_block( 291 struct xfs_scrub *sc, 292 const struct xfs_owner_info *oinfo, 293 xfs_fsblock_t *fsbno, 294 enum xfs_ag_resv_type resv) 295{ 296 struct xfs_alloc_arg args = {0}; 297 xfs_agblock_t bno; 298 int error; 299 300 switch (resv) { 301 case XFS_AG_RESV_AGFL: 302 case XFS_AG_RESV_RMAPBT: 303 error = xfs_alloc_get_freelist(sc->tp, sc->sa.agf_bp, &bno, 1); 304 if (error) 305 return error; 306 if (bno == NULLAGBLOCK) 307 return -ENOSPC; 308 xfs_extent_busy_reuse(sc->mp, sc->sa.pag, bno, 309 1, false); 310 *fsbno = XFS_AGB_TO_FSB(sc->mp, sc->sa.pag->pag_agno, bno); 311 if (resv == XFS_AG_RESV_RMAPBT) 312 xfs_ag_resv_rmapbt_alloc(sc->mp, sc->sa.pag->pag_agno); 313 return 0; 314 default: 315 break; 316 } 317 318 args.tp = sc->tp; 319 args.mp = sc->mp; 320 args.oinfo = *oinfo; 321 args.fsbno = XFS_AGB_TO_FSB(args.mp, sc->sa.pag->pag_agno, 0); 322 args.minlen = 1; 323 args.maxlen = 1; 324 args.prod = 1; 325 args.type = XFS_ALLOCTYPE_THIS_AG; 326 args.resv = resv; 327 328 error = xfs_alloc_vextent(&args); 329 if (error) 330 return error; 331 if (args.fsbno == NULLFSBLOCK) 332 return -ENOSPC; 333 ASSERT(args.len == 1); 334 *fsbno = args.fsbno; 335 336 return 0; 337} 338 339/* Initialize a new AG btree root block with zero entries. */ 340int 341xrep_init_btblock( 342 struct xfs_scrub *sc, 343 xfs_fsblock_t fsb, 344 struct xfs_buf **bpp, 345 xfs_btnum_t btnum, 346 const struct xfs_buf_ops *ops) 347{ 348 struct xfs_trans *tp = sc->tp; 349 struct xfs_mount *mp = sc->mp; 350 struct xfs_buf *bp; 351 int error; 352 353 trace_xrep_init_btblock(mp, XFS_FSB_TO_AGNO(mp, fsb), 354 XFS_FSB_TO_AGBNO(mp, fsb), btnum); 355 356 ASSERT(XFS_FSB_TO_AGNO(mp, fsb) == sc->sa.pag->pag_agno); 357 error = xfs_trans_get_buf(tp, mp->m_ddev_targp, 358 XFS_FSB_TO_DADDR(mp, fsb), XFS_FSB_TO_BB(mp, 1), 0, 359 &bp); 360 if (error) 361 return error; 362 xfs_buf_zero(bp, 0, BBTOB(bp->b_length)); 363 xfs_btree_init_block(mp, bp, btnum, 0, 0, sc->sa.pag->pag_agno); 364 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_BTREE_BUF); 365 xfs_trans_log_buf(tp, bp, 0, BBTOB(bp->b_length) - 1); 366 bp->b_ops = ops; 367 *bpp = bp; 368 369 return 0; 370} 371 372/* 373 * Reconstructing per-AG Btrees 374 * 375 * When a space btree is corrupt, we don't bother trying to fix it. Instead, 376 * we scan secondary space metadata to derive the records that should be in 377 * the damaged btree, initialize a fresh btree root, and insert the records. 378 * Note that for rebuilding the rmapbt we scan all the primary data to 379 * generate the new records. 380 * 381 * However, that leaves the matter of removing all the metadata describing the 382 * old broken structure. For primary metadata we use the rmap data to collect 383 * every extent with a matching rmap owner (bitmap); we then iterate all other 384 * metadata structures with the same rmap owner to collect the extents that 385 * cannot be removed (sublist). We then subtract sublist from bitmap to 386 * derive the blocks that were used by the old btree. These blocks can be 387 * reaped. 388 * 389 * For rmapbt reconstructions we must use different tactics for extent 390 * collection. First we iterate all primary metadata (this excludes the old 391 * rmapbt, obviously) to generate new rmap records. The gaps in the rmap 392 * records are collected as bitmap. The bnobt records are collected as 393 * sublist. As with the other btrees we subtract sublist from bitmap, and the 394 * result (since the rmapbt lives in the free space) are the blocks from the 395 * old rmapbt. 396 * 397 * Disposal of Blocks from Old per-AG Btrees 398 * 399 * Now that we've constructed a new btree to replace the damaged one, we want 400 * to dispose of the blocks that (we think) the old btree was using. 401 * Previously, we used the rmapbt to collect the extents (bitmap) with the 402 * rmap owner corresponding to the tree we rebuilt, collected extents for any 403 * blocks with the same rmap owner that are owned by another data structure 404 * (sublist), and subtracted sublist from bitmap. In theory the extents 405 * remaining in bitmap are the old btree's blocks. 406 * 407 * Unfortunately, it's possible that the btree was crosslinked with other 408 * blocks on disk. The rmap data can tell us if there are multiple owners, so 409 * if the rmapbt says there is an owner of this block other than @oinfo, then 410 * the block is crosslinked. Remove the reverse mapping and continue. 411 * 412 * If there is one rmap record, we can free the block, which removes the 413 * reverse mapping but doesn't add the block to the free space. Our repair 414 * strategy is to hope the other metadata objects crosslinked on this block 415 * will be rebuilt (atop different blocks), thereby removing all the cross 416 * links. 417 * 418 * If there are no rmap records at all, we also free the block. If the btree 419 * being rebuilt lives in the free space (bnobt/cntbt/rmapbt) then there isn't 420 * supposed to be a rmap record and everything is ok. For other btrees there 421 * had to have been an rmap entry for the block to have ended up on @bitmap, 422 * so if it's gone now there's something wrong and the fs will shut down. 423 * 424 * Note: If there are multiple rmap records with only the same rmap owner as 425 * the btree we're trying to rebuild and the block is indeed owned by another 426 * data structure with the same rmap owner, then the block will be in sublist 427 * and therefore doesn't need disposal. If there are multiple rmap records 428 * with only the same rmap owner but the block is not owned by something with 429 * the same rmap owner, the block will be freed. 430 * 431 * The caller is responsible for locking the AG headers for the entire rebuild 432 * operation so that nothing else can sneak in and change the AG state while 433 * we're not looking. We also assume that the caller already invalidated any 434 * buffers associated with @bitmap. 435 */ 436 437/* 438 * Invalidate buffers for per-AG btree blocks we're dumping. This function 439 * is not intended for use with file data repairs; we have bunmapi for that. 440 */ 441int 442xrep_invalidate_blocks( 443 struct xfs_scrub *sc, 444 struct xbitmap *bitmap) 445{ 446 struct xbitmap_range *bmr; 447 struct xbitmap_range *n; 448 struct xfs_buf *bp; 449 xfs_fsblock_t fsbno; 450 451 /* 452 * For each block in each extent, see if there's an incore buffer for 453 * exactly that block; if so, invalidate it. The buffer cache only 454 * lets us look for one buffer at a time, so we have to look one block 455 * at a time. Avoid invalidating AG headers and post-EOFS blocks 456 * because we never own those; and if we can't TRYLOCK the buffer we 457 * assume it's owned by someone else. 458 */ 459 for_each_xbitmap_block(fsbno, bmr, n, bitmap) { 460 /* Skip AG headers and post-EOFS blocks */ 461 if (!xfs_verify_fsbno(sc->mp, fsbno)) 462 continue; 463 bp = xfs_buf_incore(sc->mp->m_ddev_targp, 464 XFS_FSB_TO_DADDR(sc->mp, fsbno), 465 XFS_FSB_TO_BB(sc->mp, 1), XBF_TRYLOCK); 466 if (bp) { 467 xfs_trans_bjoin(sc->tp, bp); 468 xfs_trans_binval(sc->tp, bp); 469 } 470 } 471 472 return 0; 473} 474 475/* Ensure the freelist is the correct size. */ 476int 477xrep_fix_freelist( 478 struct xfs_scrub *sc, 479 bool can_shrink) 480{ 481 struct xfs_alloc_arg args = {0}; 482 483 args.mp = sc->mp; 484 args.tp = sc->tp; 485 args.agno = sc->sa.pag->pag_agno; 486 args.alignment = 1; 487 args.pag = sc->sa.pag; 488 489 return xfs_alloc_fix_freelist(&args, 490 can_shrink ? 0 : XFS_ALLOC_FLAG_NOSHRINK); 491} 492 493/* 494 * Put a block back on the AGFL. 495 */ 496STATIC int 497xrep_put_freelist( 498 struct xfs_scrub *sc, 499 xfs_agblock_t agbno) 500{ 501 int error; 502 503 /* Make sure there's space on the freelist. */ 504 error = xrep_fix_freelist(sc, true); 505 if (error) 506 return error; 507 508 /* 509 * Since we're "freeing" a lost block onto the AGFL, we have to 510 * create an rmap for the block prior to merging it or else other 511 * parts will break. 512 */ 513 error = xfs_rmap_alloc(sc->tp, sc->sa.agf_bp, sc->sa.pag, agbno, 1, 514 &XFS_RMAP_OINFO_AG); 515 if (error) 516 return error; 517 518 /* Put the block on the AGFL. */ 519 error = xfs_alloc_put_freelist(sc->tp, sc->sa.agf_bp, sc->sa.agfl_bp, 520 agbno, 0); 521 if (error) 522 return error; 523 xfs_extent_busy_insert(sc->tp, sc->sa.pag, agbno, 1, 524 XFS_EXTENT_BUSY_SKIP_DISCARD); 525 526 return 0; 527} 528 529/* Dispose of a single block. */ 530STATIC int 531xrep_reap_block( 532 struct xfs_scrub *sc, 533 xfs_fsblock_t fsbno, 534 const struct xfs_owner_info *oinfo, 535 enum xfs_ag_resv_type resv) 536{ 537 struct xfs_btree_cur *cur; 538 struct xfs_buf *agf_bp = NULL; 539 xfs_agnumber_t agno; 540 xfs_agblock_t agbno; 541 bool has_other_rmap; 542 int error; 543 544 agno = XFS_FSB_TO_AGNO(sc->mp, fsbno); 545 agbno = XFS_FSB_TO_AGBNO(sc->mp, fsbno); 546 547 /* 548 * If we are repairing per-inode metadata, we need to read in the AGF 549 * buffer. Otherwise, we're repairing a per-AG structure, so reuse 550 * the AGF buffer that the setup functions already grabbed. 551 */ 552 if (sc->ip) { 553 error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf_bp); 554 if (error) 555 return error; 556 } else { 557 agf_bp = sc->sa.agf_bp; 558 } 559 cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf_bp, sc->sa.pag); 560 561 /* Can we find any other rmappings? */ 562 error = xfs_rmap_has_other_keys(cur, agbno, 1, oinfo, &has_other_rmap); 563 xfs_btree_del_cursor(cur, error); 564 if (error) 565 goto out_free; 566 567 /* 568 * If there are other rmappings, this block is cross linked and must 569 * not be freed. Remove the reverse mapping and move on. Otherwise, 570 * we were the only owner of the block, so free the extent, which will 571 * also remove the rmap. 572 * 573 * XXX: XFS doesn't support detecting the case where a single block 574 * metadata structure is crosslinked with a multi-block structure 575 * because the buffer cache doesn't detect aliasing problems, so we 576 * can't fix 100% of crosslinking problems (yet). The verifiers will 577 * blow on writeout, the filesystem will shut down, and the admin gets 578 * to run xfs_repair. 579 */ 580 if (has_other_rmap) 581 error = xfs_rmap_free(sc->tp, agf_bp, sc->sa.pag, agbno, 582 1, oinfo); 583 else if (resv == XFS_AG_RESV_AGFL) 584 error = xrep_put_freelist(sc, agbno); 585 else 586 error = xfs_free_extent(sc->tp, fsbno, 1, oinfo, resv); 587 if (agf_bp != sc->sa.agf_bp) 588 xfs_trans_brelse(sc->tp, agf_bp); 589 if (error) 590 return error; 591 592 if (sc->ip) 593 return xfs_trans_roll_inode(&sc->tp, sc->ip); 594 return xrep_roll_ag_trans(sc); 595 596out_free: 597 if (agf_bp != sc->sa.agf_bp) 598 xfs_trans_brelse(sc->tp, agf_bp); 599 return error; 600} 601 602/* Dispose of every block of every extent in the bitmap. */ 603int 604xrep_reap_extents( 605 struct xfs_scrub *sc, 606 struct xbitmap *bitmap, 607 const struct xfs_owner_info *oinfo, 608 enum xfs_ag_resv_type type) 609{ 610 struct xbitmap_range *bmr; 611 struct xbitmap_range *n; 612 xfs_fsblock_t fsbno; 613 int error = 0; 614 615 ASSERT(xfs_has_rmapbt(sc->mp)); 616 617 for_each_xbitmap_block(fsbno, bmr, n, bitmap) { 618 ASSERT(sc->ip != NULL || 619 XFS_FSB_TO_AGNO(sc->mp, fsbno) == sc->sa.pag->pag_agno); 620 trace_xrep_dispose_btree_extent(sc->mp, 621 XFS_FSB_TO_AGNO(sc->mp, fsbno), 622 XFS_FSB_TO_AGBNO(sc->mp, fsbno), 1); 623 624 error = xrep_reap_block(sc, fsbno, oinfo, type); 625 if (error) 626 break; 627 } 628 629 return error; 630} 631 632/* 633 * Finding per-AG Btree Roots for AGF/AGI Reconstruction 634 * 635 * If the AGF or AGI become slightly corrupted, it may be necessary to rebuild 636 * the AG headers by using the rmap data to rummage through the AG looking for 637 * btree roots. This is not guaranteed to work if the AG is heavily damaged 638 * or the rmap data are corrupt. 639 * 640 * Callers of xrep_find_ag_btree_roots must lock the AGF and AGFL 641 * buffers if the AGF is being rebuilt; or the AGF and AGI buffers if the 642 * AGI is being rebuilt. It must maintain these locks until it's safe for 643 * other threads to change the btrees' shapes. The caller provides 644 * information about the btrees to look for by passing in an array of 645 * xrep_find_ag_btree with the (rmap owner, buf_ops, magic) fields set. 646 * The (root, height) fields will be set on return if anything is found. The 647 * last element of the array should have a NULL buf_ops to mark the end of the 648 * array. 649 * 650 * For every rmapbt record matching any of the rmap owners in btree_info, 651 * read each block referenced by the rmap record. If the block is a btree 652 * block from this filesystem matching any of the magic numbers and has a 653 * level higher than what we've already seen, remember the block and the 654 * height of the tree required to have such a block. When the call completes, 655 * we return the highest block we've found for each btree description; those 656 * should be the roots. 657 */ 658 659struct xrep_findroot { 660 struct xfs_scrub *sc; 661 struct xfs_buf *agfl_bp; 662 struct xfs_agf *agf; 663 struct xrep_find_ag_btree *btree_info; 664}; 665 666/* See if our block is in the AGFL. */ 667STATIC int 668xrep_findroot_agfl_walk( 669 struct xfs_mount *mp, 670 xfs_agblock_t bno, 671 void *priv) 672{ 673 xfs_agblock_t *agbno = priv; 674 675 return (*agbno == bno) ? -ECANCELED : 0; 676} 677 678/* Does this block match the btree information passed in? */ 679STATIC int 680xrep_findroot_block( 681 struct xrep_findroot *ri, 682 struct xrep_find_ag_btree *fab, 683 uint64_t owner, 684 xfs_agblock_t agbno, 685 bool *done_with_block) 686{ 687 struct xfs_mount *mp = ri->sc->mp; 688 struct xfs_buf *bp; 689 struct xfs_btree_block *btblock; 690 xfs_daddr_t daddr; 691 int block_level; 692 int error = 0; 693 694 daddr = XFS_AGB_TO_DADDR(mp, ri->sc->sa.pag->pag_agno, agbno); 695 696 /* 697 * Blocks in the AGFL have stale contents that might just happen to 698 * have a matching magic and uuid. We don't want to pull these blocks 699 * in as part of a tree root, so we have to filter out the AGFL stuff 700 * here. If the AGFL looks insane we'll just refuse to repair. 701 */ 702 if (owner == XFS_RMAP_OWN_AG) { 703 error = xfs_agfl_walk(mp, ri->agf, ri->agfl_bp, 704 xrep_findroot_agfl_walk, &agbno); 705 if (error == -ECANCELED) 706 return 0; 707 if (error) 708 return error; 709 } 710 711 /* 712 * Read the buffer into memory so that we can see if it's a match for 713 * our btree type. We have no clue if it is beforehand, and we want to 714 * avoid xfs_trans_read_buf's behavior of dumping the DONE state (which 715 * will cause needless disk reads in subsequent calls to this function) 716 * and logging metadata verifier failures. 717 * 718 * Therefore, pass in NULL buffer ops. If the buffer was already in 719 * memory from some other caller it will already have b_ops assigned. 720 * If it was in memory from a previous unsuccessful findroot_block 721 * call, the buffer won't have b_ops but it should be clean and ready 722 * for us to try to verify if the read call succeeds. The same applies 723 * if the buffer wasn't in memory at all. 724 * 725 * Note: If we never match a btree type with this buffer, it will be 726 * left in memory with NULL b_ops. This shouldn't be a problem unless 727 * the buffer gets written. 728 */ 729 error = xfs_trans_read_buf(mp, ri->sc->tp, mp->m_ddev_targp, daddr, 730 mp->m_bsize, 0, &bp, NULL); 731 if (error) 732 return error; 733 734 /* Ensure the block magic matches the btree type we're looking for. */ 735 btblock = XFS_BUF_TO_BLOCK(bp); 736 ASSERT(fab->buf_ops->magic[1] != 0); 737 if (btblock->bb_magic != fab->buf_ops->magic[1]) 738 goto out; 739 740 /* 741 * If the buffer already has ops applied and they're not the ones for 742 * this btree type, we know this block doesn't match the btree and we 743 * can bail out. 744 * 745 * If the buffer ops match ours, someone else has already validated 746 * the block for us, so we can move on to checking if this is a root 747 * block candidate. 748 * 749 * If the buffer does not have ops, nobody has successfully validated 750 * the contents and the buffer cannot be dirty. If the magic, uuid, 751 * and structure match this btree type then we'll move on to checking 752 * if it's a root block candidate. If there is no match, bail out. 753 */ 754 if (bp->b_ops) { 755 if (bp->b_ops != fab->buf_ops) 756 goto out; 757 } else { 758 ASSERT(!xfs_trans_buf_is_dirty(bp)); 759 if (!uuid_equal(&btblock->bb_u.s.bb_uuid, 760 &mp->m_sb.sb_meta_uuid)) 761 goto out; 762 /* 763 * Read verifiers can reference b_ops, so we set the pointer 764 * here. If the verifier fails we'll reset the buffer state 765 * to what it was before we touched the buffer. 766 */ 767 bp->b_ops = fab->buf_ops; 768 fab->buf_ops->verify_read(bp); 769 if (bp->b_error) { 770 bp->b_ops = NULL; 771 bp->b_error = 0; 772 goto out; 773 } 774 775 /* 776 * Some read verifiers will (re)set b_ops, so we must be 777 * careful not to change b_ops after running the verifier. 778 */ 779 } 780 781 /* 782 * This block passes the magic/uuid and verifier tests for this btree 783 * type. We don't need the caller to try the other tree types. 784 */ 785 *done_with_block = true; 786 787 /* 788 * Compare this btree block's level to the height of the current 789 * candidate root block. 790 * 791 * If the level matches the root we found previously, throw away both 792 * blocks because there can't be two candidate roots. 793 * 794 * If level is lower in the tree than the root we found previously, 795 * ignore this block. 796 */ 797 block_level = xfs_btree_get_level(btblock); 798 if (block_level + 1 == fab->height) { 799 fab->root = NULLAGBLOCK; 800 goto out; 801 } else if (block_level < fab->height) { 802 goto out; 803 } 804 805 /* 806 * This is the highest block in the tree that we've found so far. 807 * Update the btree height to reflect what we've learned from this 808 * block. 809 */ 810 fab->height = block_level + 1; 811 812 /* 813 * If this block doesn't have sibling pointers, then it's the new root 814 * block candidate. Otherwise, the root will be found farther up the 815 * tree. 816 */ 817 if (btblock->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) && 818 btblock->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK)) 819 fab->root = agbno; 820 else 821 fab->root = NULLAGBLOCK; 822 823 trace_xrep_findroot_block(mp, ri->sc->sa.pag->pag_agno, agbno, 824 be32_to_cpu(btblock->bb_magic), fab->height - 1); 825out: 826 xfs_trans_brelse(ri->sc->tp, bp); 827 return error; 828} 829 830/* 831 * Do any of the blocks in this rmap record match one of the btrees we're 832 * looking for? 833 */ 834STATIC int 835xrep_findroot_rmap( 836 struct xfs_btree_cur *cur, 837 const struct xfs_rmap_irec *rec, 838 void *priv) 839{ 840 struct xrep_findroot *ri = priv; 841 struct xrep_find_ag_btree *fab; 842 xfs_agblock_t b; 843 bool done; 844 int error = 0; 845 846 /* Ignore anything that isn't AG metadata. */ 847 if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner)) 848 return 0; 849 850 /* Otherwise scan each block + btree type. */ 851 for (b = 0; b < rec->rm_blockcount; b++) { 852 done = false; 853 for (fab = ri->btree_info; fab->buf_ops; fab++) { 854 if (rec->rm_owner != fab->rmap_owner) 855 continue; 856 error = xrep_findroot_block(ri, fab, 857 rec->rm_owner, rec->rm_startblock + b, 858 &done); 859 if (error) 860 return error; 861 if (done) 862 break; 863 } 864 } 865 866 return 0; 867} 868 869/* Find the roots of the per-AG btrees described in btree_info. */ 870int 871xrep_find_ag_btree_roots( 872 struct xfs_scrub *sc, 873 struct xfs_buf *agf_bp, 874 struct xrep_find_ag_btree *btree_info, 875 struct xfs_buf *agfl_bp) 876{ 877 struct xfs_mount *mp = sc->mp; 878 struct xrep_findroot ri; 879 struct xrep_find_ag_btree *fab; 880 struct xfs_btree_cur *cur; 881 int error; 882 883 ASSERT(xfs_buf_islocked(agf_bp)); 884 ASSERT(agfl_bp == NULL || xfs_buf_islocked(agfl_bp)); 885 886 ri.sc = sc; 887 ri.btree_info = btree_info; 888 ri.agf = agf_bp->b_addr; 889 ri.agfl_bp = agfl_bp; 890 for (fab = btree_info; fab->buf_ops; fab++) { 891 ASSERT(agfl_bp || fab->rmap_owner != XFS_RMAP_OWN_AG); 892 ASSERT(XFS_RMAP_NON_INODE_OWNER(fab->rmap_owner)); 893 fab->root = NULLAGBLOCK; 894 fab->height = 0; 895 } 896 897 cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag); 898 error = xfs_rmap_query_all(cur, xrep_findroot_rmap, &ri); 899 xfs_btree_del_cursor(cur, error); 900 901 return error; 902} 903 904/* Force a quotacheck the next time we mount. */ 905void 906xrep_force_quotacheck( 907 struct xfs_scrub *sc, 908 xfs_dqtype_t type) 909{ 910 uint flag; 911 912 flag = xfs_quota_chkd_flag(type); 913 if (!(flag & sc->mp->m_qflags)) 914 return; 915 916 mutex_lock(&sc->mp->m_quotainfo->qi_quotaofflock); 917 sc->mp->m_qflags &= ~flag; 918 spin_lock(&sc->mp->m_sb_lock); 919 sc->mp->m_sb.sb_qflags &= ~flag; 920 spin_unlock(&sc->mp->m_sb_lock); 921 xfs_log_sb(sc->tp); 922 mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock); 923} 924 925/* 926 * Attach dquots to this inode, or schedule quotacheck to fix them. 927 * 928 * This function ensures that the appropriate dquots are attached to an inode. 929 * We cannot allow the dquot code to allocate an on-disk dquot block here 930 * because we're already in transaction context with the inode locked. The 931 * on-disk dquot should already exist anyway. If the quota code signals 932 * corruption or missing quota information, schedule quotacheck, which will 933 * repair corruptions in the quota metadata. 934 */ 935int 936xrep_ino_dqattach( 937 struct xfs_scrub *sc) 938{ 939 int error; 940 941 error = xfs_qm_dqattach_locked(sc->ip, false); 942 switch (error) { 943 case -EFSBADCRC: 944 case -EFSCORRUPTED: 945 case -ENOENT: 946 xfs_err_ratelimited(sc->mp, 947"inode %llu repair encountered quota error %d, quotacheck forced.", 948 (unsigned long long)sc->ip->i_ino, error); 949 if (XFS_IS_UQUOTA_ON(sc->mp) && !sc->ip->i_udquot) 950 xrep_force_quotacheck(sc, XFS_DQTYPE_USER); 951 if (XFS_IS_GQUOTA_ON(sc->mp) && !sc->ip->i_gdquot) 952 xrep_force_quotacheck(sc, XFS_DQTYPE_GROUP); 953 if (XFS_IS_PQUOTA_ON(sc->mp) && !sc->ip->i_pdquot) 954 xrep_force_quotacheck(sc, XFS_DQTYPE_PROJ); 955 fallthrough; 956 case -ESRCH: 957 error = 0; 958 break; 959 default: 960 break; 961 } 962 963 return error; 964}