1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include "xfs_fs.h" 8 #include "xfs_format.h" 9 #include "xfs_log_format.h" 10 #include "xfs_shared.h" 11 #include "xfs_trans_resv.h" 12 #include "xfs_bit.h" 13 #include "xfs_sb.h" 14 #include "xfs_mount.h" 15 #include "xfs_defer.h" 16 #include "xfs_btree.h" 17 #include "xfs_rmap.h" 18 #include "xfs_alloc_btree.h" 19 #include "xfs_alloc.h" 20 #include "xfs_extent_busy.h" 21 #include "xfs_errortag.h" 22 #include "xfs_error.h" 23 #include "xfs_trace.h" 24 #include "xfs_trans.h" 25 #include "xfs_buf_item.h" 26 #include "xfs_log.h" 27 #include "xfs_ag_resv.h" 28 #include "xfs_bmap.h" 29 30 extern kmem_zone_t *xfs_bmap_free_item_zone; 31 32 struct workqueue_struct *xfs_alloc_wq; 33 34 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b))) 35 36 #define XFSA_FIXUP_BNO_OK 1 37 #define XFSA_FIXUP_CNT_OK 2 38 39 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *); 40 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *); 41 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *); 42 43 /* 44 * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in 45 * the beginning of the block for a proper header with the location information 46 * and CRC. 47 */ 48 unsigned int 49 xfs_agfl_size( 50 struct xfs_mount *mp) 51 { 52 unsigned int size = mp->m_sb.sb_sectsize; 53 54 if (xfs_sb_version_hascrc(&mp->m_sb)) 55 size -= sizeof(struct xfs_agfl); 56 57 return size / sizeof(xfs_agblock_t); 58 } 59 60 unsigned int 61 xfs_refc_block( 62 struct xfs_mount *mp) 63 { 64 if (xfs_sb_version_hasrmapbt(&mp->m_sb)) 65 return XFS_RMAP_BLOCK(mp) + 1; 66 if (xfs_sb_version_hasfinobt(&mp->m_sb)) 67 return XFS_FIBT_BLOCK(mp) + 1; 68 return XFS_IBT_BLOCK(mp) + 1; 69 } 70 71 xfs_extlen_t 72 xfs_prealloc_blocks( 73 struct xfs_mount *mp) 74 { 75 if (xfs_sb_version_hasreflink(&mp->m_sb)) 76 return xfs_refc_block(mp) + 1; 77 if (xfs_sb_version_hasrmapbt(&mp->m_sb)) 78 return XFS_RMAP_BLOCK(mp) + 1; 79 if (xfs_sb_version_hasfinobt(&mp->m_sb)) 80 return XFS_FIBT_BLOCK(mp) + 1; 81 return XFS_IBT_BLOCK(mp) + 1; 82 } 83 84 /* 85 * In order to avoid ENOSPC-related deadlock caused by out-of-order locking of 86 * AGF buffer (PV 947395), we place constraints on the relationship among 87 * actual allocations for data blocks, freelist blocks, and potential file data 88 * bmap btree blocks. However, these restrictions may result in no actual space 89 * allocated for a delayed extent, for example, a data block in a certain AG is 90 * allocated but there is no additional block for the additional bmap btree 91 * block due to a split of the bmap btree of the file. The result of this may 92 * lead to an infinite loop when the file gets flushed to disk and all delayed 93 * extents need to be actually allocated. To get around this, we explicitly set 94 * aside a few blocks which will not be reserved in delayed allocation. 95 * 96 * We need to reserve 4 fsbs _per AG_ for the freelist and 4 more to handle a 97 * potential split of the file's bmap btree. 98 */ 99 unsigned int 100 xfs_alloc_set_aside( 101 struct xfs_mount *mp) 102 { 103 return mp->m_sb.sb_agcount * (XFS_ALLOC_AGFL_RESERVE + 4); 104 } 105 106 /* 107 * When deciding how much space to allocate out of an AG, we limit the 108 * allocation maximum size to the size the AG. However, we cannot use all the 109 * blocks in the AG - some are permanently used by metadata. These 110 * blocks are generally: 111 * - the AG superblock, AGF, AGI and AGFL 112 * - the AGF (bno and cnt) and AGI btree root blocks, and optionally 113 * the AGI free inode and rmap btree root blocks. 114 * - blocks on the AGFL according to xfs_alloc_set_aside() limits 115 * - the rmapbt root block 116 * 117 * The AG headers are sector sized, so the amount of space they take up is 118 * dependent on filesystem geometry. The others are all single blocks. 119 */ 120 unsigned int 121 xfs_alloc_ag_max_usable( 122 struct xfs_mount *mp) 123 { 124 unsigned int blocks; 125 126 blocks = XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)); /* ag headers */ 127 blocks += XFS_ALLOC_AGFL_RESERVE; 128 blocks += 3; /* AGF, AGI btree root blocks */ 129 if (xfs_sb_version_hasfinobt(&mp->m_sb)) 130 blocks++; /* finobt root block */ 131 if (xfs_sb_version_hasrmapbt(&mp->m_sb)) 132 blocks++; /* rmap root block */ 133 if (xfs_sb_version_hasreflink(&mp->m_sb)) 134 blocks++; /* refcount root block */ 135 136 return mp->m_sb.sb_agblocks - blocks; 137 } 138 139 /* 140 * Lookup the record equal to [bno, len] in the btree given by cur. 141 */ 142 STATIC int /* error */ 143 xfs_alloc_lookup_eq( 144 struct xfs_btree_cur *cur, /* btree cursor */ 145 xfs_agblock_t bno, /* starting block of extent */ 146 xfs_extlen_t len, /* length of extent */ 147 int *stat) /* success/failure */ 148 { 149 cur->bc_rec.a.ar_startblock = bno; 150 cur->bc_rec.a.ar_blockcount = len; 151 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat); 152 } 153 154 /* 155 * Lookup the first record greater than or equal to [bno, len] 156 * in the btree given by cur. 157 */ 158 int /* error */ 159 xfs_alloc_lookup_ge( 160 struct xfs_btree_cur *cur, /* btree cursor */ 161 xfs_agblock_t bno, /* starting block of extent */ 162 xfs_extlen_t len, /* length of extent */ 163 int *stat) /* success/failure */ 164 { 165 cur->bc_rec.a.ar_startblock = bno; 166 cur->bc_rec.a.ar_blockcount = len; 167 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); 168 } 169 170 /* 171 * Lookup the first record less than or equal to [bno, len] 172 * in the btree given by cur. 173 */ 174 int /* error */ 175 xfs_alloc_lookup_le( 176 struct xfs_btree_cur *cur, /* btree cursor */ 177 xfs_agblock_t bno, /* starting block of extent */ 178 xfs_extlen_t len, /* length of extent */ 179 int *stat) /* success/failure */ 180 { 181 cur->bc_rec.a.ar_startblock = bno; 182 cur->bc_rec.a.ar_blockcount = len; 183 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); 184 } 185 186 /* 187 * Update the record referred to by cur to the value given 188 * by [bno, len]. 189 * This either works (return 0) or gets an EFSCORRUPTED error. 190 */ 191 STATIC int /* error */ 192 xfs_alloc_update( 193 struct xfs_btree_cur *cur, /* btree cursor */ 194 xfs_agblock_t bno, /* starting block of extent */ 195 xfs_extlen_t len) /* length of extent */ 196 { 197 union xfs_btree_rec rec; 198 199 rec.alloc.ar_startblock = cpu_to_be32(bno); 200 rec.alloc.ar_blockcount = cpu_to_be32(len); 201 return xfs_btree_update(cur, &rec); 202 } 203 204 /* 205 * Get the data from the pointed-to record. 206 */ 207 int /* error */ 208 xfs_alloc_get_rec( 209 struct xfs_btree_cur *cur, /* btree cursor */ 210 xfs_agblock_t *bno, /* output: starting block of extent */ 211 xfs_extlen_t *len, /* output: length of extent */ 212 int *stat) /* output: success/failure */ 213 { 214 struct xfs_mount *mp = cur->bc_mp; 215 xfs_agnumber_t agno = cur->bc_private.a.agno; 216 union xfs_btree_rec *rec; 217 int error; 218 219 error = xfs_btree_get_rec(cur, &rec, stat); 220 if (error || !(*stat)) 221 return error; 222 223 *bno = be32_to_cpu(rec->alloc.ar_startblock); 224 *len = be32_to_cpu(rec->alloc.ar_blockcount); 225 226 if (*len == 0) 227 goto out_bad_rec; 228 229 /* check for valid extent range, including overflow */ 230 if (!xfs_verify_agbno(mp, agno, *bno)) 231 goto out_bad_rec; 232 if (*bno > *bno + *len) 233 goto out_bad_rec; 234 if (!xfs_verify_agbno(mp, agno, *bno + *len - 1)) 235 goto out_bad_rec; 236 237 return 0; 238 239 out_bad_rec: 240 xfs_warn(mp, 241 "%s Freespace BTree record corruption in AG %d detected!", 242 cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", agno); 243 xfs_warn(mp, 244 "start block 0x%x block count 0x%x", *bno, *len); 245 return -EFSCORRUPTED; 246 } 247 248 /* 249 * Compute aligned version of the found extent. 250 * Takes alignment and min length into account. 251 */ 252 STATIC bool 253 xfs_alloc_compute_aligned( 254 xfs_alloc_arg_t *args, /* allocation argument structure */ 255 xfs_agblock_t foundbno, /* starting block in found extent */ 256 xfs_extlen_t foundlen, /* length in found extent */ 257 xfs_agblock_t *resbno, /* result block number */ 258 xfs_extlen_t *reslen, /* result length */ 259 unsigned *busy_gen) 260 { 261 xfs_agblock_t bno = foundbno; 262 xfs_extlen_t len = foundlen; 263 xfs_extlen_t diff; 264 bool busy; 265 266 /* Trim busy sections out of found extent */ 267 busy = xfs_extent_busy_trim(args, &bno, &len, busy_gen); 268 269 /* 270 * If we have a largish extent that happens to start before min_agbno, 271 * see if we can shift it into range... 272 */ 273 if (bno < args->min_agbno && bno + len > args->min_agbno) { 274 diff = args->min_agbno - bno; 275 if (len > diff) { 276 bno += diff; 277 len -= diff; 278 } 279 } 280 281 if (args->alignment > 1 && len >= args->minlen) { 282 xfs_agblock_t aligned_bno = roundup(bno, args->alignment); 283 284 diff = aligned_bno - bno; 285 286 *resbno = aligned_bno; 287 *reslen = diff >= len ? 0 : len - diff; 288 } else { 289 *resbno = bno; 290 *reslen = len; 291 } 292 293 return busy; 294 } 295 296 /* 297 * Compute best start block and diff for "near" allocations. 298 * freelen >= wantlen already checked by caller. 299 */ 300 STATIC xfs_extlen_t /* difference value (absolute) */ 301 xfs_alloc_compute_diff( 302 xfs_agblock_t wantbno, /* target starting block */ 303 xfs_extlen_t wantlen, /* target length */ 304 xfs_extlen_t alignment, /* target alignment */ 305 int datatype, /* are we allocating data? */ 306 xfs_agblock_t freebno, /* freespace's starting block */ 307 xfs_extlen_t freelen, /* freespace's length */ 308 xfs_agblock_t *newbnop) /* result: best start block from free */ 309 { 310 xfs_agblock_t freeend; /* end of freespace extent */ 311 xfs_agblock_t newbno1; /* return block number */ 312 xfs_agblock_t newbno2; /* other new block number */ 313 xfs_extlen_t newlen1=0; /* length with newbno1 */ 314 xfs_extlen_t newlen2=0; /* length with newbno2 */ 315 xfs_agblock_t wantend; /* end of target extent */ 316 bool userdata = xfs_alloc_is_userdata(datatype); 317 318 ASSERT(freelen >= wantlen); 319 freeend = freebno + freelen; 320 wantend = wantbno + wantlen; 321 /* 322 * We want to allocate from the start of a free extent if it is past 323 * the desired block or if we are allocating user data and the free 324 * extent is before desired block. The second case is there to allow 325 * for contiguous allocation from the remaining free space if the file 326 * grows in the short term. 327 */ 328 if (freebno >= wantbno || (userdata && freeend < wantend)) { 329 if ((newbno1 = roundup(freebno, alignment)) >= freeend) 330 newbno1 = NULLAGBLOCK; 331 } else if (freeend >= wantend && alignment > 1) { 332 newbno1 = roundup(wantbno, alignment); 333 newbno2 = newbno1 - alignment; 334 if (newbno1 >= freeend) 335 newbno1 = NULLAGBLOCK; 336 else 337 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1); 338 if (newbno2 < freebno) 339 newbno2 = NULLAGBLOCK; 340 else 341 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2); 342 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) { 343 if (newlen1 < newlen2 || 344 (newlen1 == newlen2 && 345 XFS_ABSDIFF(newbno1, wantbno) > 346 XFS_ABSDIFF(newbno2, wantbno))) 347 newbno1 = newbno2; 348 } else if (newbno2 != NULLAGBLOCK) 349 newbno1 = newbno2; 350 } else if (freeend >= wantend) { 351 newbno1 = wantbno; 352 } else if (alignment > 1) { 353 newbno1 = roundup(freeend - wantlen, alignment); 354 if (newbno1 > freeend - wantlen && 355 newbno1 - alignment >= freebno) 356 newbno1 -= alignment; 357 else if (newbno1 >= freeend) 358 newbno1 = NULLAGBLOCK; 359 } else 360 newbno1 = freeend - wantlen; 361 *newbnop = newbno1; 362 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno); 363 } 364 365 /* 366 * Fix up the length, based on mod and prod. 367 * len should be k * prod + mod for some k. 368 * If len is too small it is returned unchanged. 369 * If len hits maxlen it is left alone. 370 */ 371 STATIC void 372 xfs_alloc_fix_len( 373 xfs_alloc_arg_t *args) /* allocation argument structure */ 374 { 375 xfs_extlen_t k; 376 xfs_extlen_t rlen; 377 378 ASSERT(args->mod < args->prod); 379 rlen = args->len; 380 ASSERT(rlen >= args->minlen); 381 ASSERT(rlen <= args->maxlen); 382 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen || 383 (args->mod == 0 && rlen < args->prod)) 384 return; 385 k = rlen % args->prod; 386 if (k == args->mod) 387 return; 388 if (k > args->mod) 389 rlen = rlen - (k - args->mod); 390 else 391 rlen = rlen - args->prod + (args->mod - k); 392 /* casts to (int) catch length underflows */ 393 if ((int)rlen < (int)args->minlen) 394 return; 395 ASSERT(rlen >= args->minlen && rlen <= args->maxlen); 396 ASSERT(rlen % args->prod == args->mod); 397 ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >= 398 rlen + args->minleft); 399 args->len = rlen; 400 } 401 402 /* 403 * Update the two btrees, logically removing from freespace the extent 404 * starting at rbno, rlen blocks. The extent is contained within the 405 * actual (current) free extent fbno for flen blocks. 406 * Flags are passed in indicating whether the cursors are set to the 407 * relevant records. 408 */ 409 STATIC int /* error code */ 410 xfs_alloc_fixup_trees( 411 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */ 412 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */ 413 xfs_agblock_t fbno, /* starting block of free extent */ 414 xfs_extlen_t flen, /* length of free extent */ 415 xfs_agblock_t rbno, /* starting block of returned extent */ 416 xfs_extlen_t rlen, /* length of returned extent */ 417 int flags) /* flags, XFSA_FIXUP_... */ 418 { 419 int error; /* error code */ 420 int i; /* operation results */ 421 xfs_agblock_t nfbno1; /* first new free startblock */ 422 xfs_agblock_t nfbno2; /* second new free startblock */ 423 xfs_extlen_t nflen1=0; /* first new free length */ 424 xfs_extlen_t nflen2=0; /* second new free length */ 425 struct xfs_mount *mp; 426 427 mp = cnt_cur->bc_mp; 428 429 /* 430 * Look up the record in the by-size tree if necessary. 431 */ 432 if (flags & XFSA_FIXUP_CNT_OK) { 433 #ifdef DEBUG 434 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i))) 435 return error; 436 XFS_WANT_CORRUPTED_RETURN(mp, 437 i == 1 && nfbno1 == fbno && nflen1 == flen); 438 #endif 439 } else { 440 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i))) 441 return error; 442 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 443 } 444 /* 445 * Look up the record in the by-block tree if necessary. 446 */ 447 if (flags & XFSA_FIXUP_BNO_OK) { 448 #ifdef DEBUG 449 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i))) 450 return error; 451 XFS_WANT_CORRUPTED_RETURN(mp, 452 i == 1 && nfbno1 == fbno && nflen1 == flen); 453 #endif 454 } else { 455 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i))) 456 return error; 457 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 458 } 459 460 #ifdef DEBUG 461 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) { 462 struct xfs_btree_block *bnoblock; 463 struct xfs_btree_block *cntblock; 464 465 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]); 466 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]); 467 468 XFS_WANT_CORRUPTED_RETURN(mp, 469 bnoblock->bb_numrecs == cntblock->bb_numrecs); 470 } 471 #endif 472 473 /* 474 * Deal with all four cases: the allocated record is contained 475 * within the freespace record, so we can have new freespace 476 * at either (or both) end, or no freespace remaining. 477 */ 478 if (rbno == fbno && rlen == flen) 479 nfbno1 = nfbno2 = NULLAGBLOCK; 480 else if (rbno == fbno) { 481 nfbno1 = rbno + rlen; 482 nflen1 = flen - rlen; 483 nfbno2 = NULLAGBLOCK; 484 } else if (rbno + rlen == fbno + flen) { 485 nfbno1 = fbno; 486 nflen1 = flen - rlen; 487 nfbno2 = NULLAGBLOCK; 488 } else { 489 nfbno1 = fbno; 490 nflen1 = rbno - fbno; 491 nfbno2 = rbno + rlen; 492 nflen2 = (fbno + flen) - nfbno2; 493 } 494 /* 495 * Delete the entry from the by-size btree. 496 */ 497 if ((error = xfs_btree_delete(cnt_cur, &i))) 498 return error; 499 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 500 /* 501 * Add new by-size btree entry(s). 502 */ 503 if (nfbno1 != NULLAGBLOCK) { 504 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i))) 505 return error; 506 XFS_WANT_CORRUPTED_RETURN(mp, i == 0); 507 if ((error = xfs_btree_insert(cnt_cur, &i))) 508 return error; 509 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 510 } 511 if (nfbno2 != NULLAGBLOCK) { 512 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i))) 513 return error; 514 XFS_WANT_CORRUPTED_RETURN(mp, i == 0); 515 if ((error = xfs_btree_insert(cnt_cur, &i))) 516 return error; 517 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 518 } 519 /* 520 * Fix up the by-block btree entry(s). 521 */ 522 if (nfbno1 == NULLAGBLOCK) { 523 /* 524 * No remaining freespace, just delete the by-block tree entry. 525 */ 526 if ((error = xfs_btree_delete(bno_cur, &i))) 527 return error; 528 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 529 } else { 530 /* 531 * Update the by-block entry to start later|be shorter. 532 */ 533 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1))) 534 return error; 535 } 536 if (nfbno2 != NULLAGBLOCK) { 537 /* 538 * 2 resulting free entries, need to add one. 539 */ 540 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i))) 541 return error; 542 XFS_WANT_CORRUPTED_RETURN(mp, i == 0); 543 if ((error = xfs_btree_insert(bno_cur, &i))) 544 return error; 545 XFS_WANT_CORRUPTED_RETURN(mp, i == 1); 546 } 547 return 0; 548 } 549 550 static xfs_failaddr_t 551 xfs_agfl_verify( 552 struct xfs_buf *bp) 553 { 554 struct xfs_mount *mp = bp->b_mount; 555 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp); 556 int i; 557 558 /* 559 * There is no verification of non-crc AGFLs because mkfs does not 560 * initialise the AGFL to zero or NULL. Hence the only valid part of the 561 * AGFL is what the AGF says is active. We can't get to the AGF, so we 562 * can't verify just those entries are valid. 563 */ 564 if (!xfs_sb_version_hascrc(&mp->m_sb)) 565 return NULL; 566 567 if (!xfs_verify_magic(bp, agfl->agfl_magicnum)) 568 return __this_address; 569 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid)) 570 return __this_address; 571 /* 572 * during growfs operations, the perag is not fully initialised, 573 * so we can't use it for any useful checking. growfs ensures we can't 574 * use it by using uncached buffers that don't have the perag attached 575 * so we can detect and avoid this problem. 576 */ 577 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno) 578 return __this_address; 579 580 for (i = 0; i < xfs_agfl_size(mp); i++) { 581 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK && 582 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks) 583 return __this_address; 584 } 585 586 if (!xfs_log_check_lsn(mp, be64_to_cpu(XFS_BUF_TO_AGFL(bp)->agfl_lsn))) 587 return __this_address; 588 return NULL; 589 } 590 591 static void 592 xfs_agfl_read_verify( 593 struct xfs_buf *bp) 594 { 595 struct xfs_mount *mp = bp->b_mount; 596 xfs_failaddr_t fa; 597 598 /* 599 * There is no verification of non-crc AGFLs because mkfs does not 600 * initialise the AGFL to zero or NULL. Hence the only valid part of the 601 * AGFL is what the AGF says is active. We can't get to the AGF, so we 602 * can't verify just those entries are valid. 603 */ 604 if (!xfs_sb_version_hascrc(&mp->m_sb)) 605 return; 606 607 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF)) 608 xfs_verifier_error(bp, -EFSBADCRC, __this_address); 609 else { 610 fa = xfs_agfl_verify(bp); 611 if (fa) 612 xfs_verifier_error(bp, -EFSCORRUPTED, fa); 613 } 614 } 615 616 static void 617 xfs_agfl_write_verify( 618 struct xfs_buf *bp) 619 { 620 struct xfs_mount *mp = bp->b_mount; 621 struct xfs_buf_log_item *bip = bp->b_log_item; 622 xfs_failaddr_t fa; 623 624 /* no verification of non-crc AGFLs */ 625 if (!xfs_sb_version_hascrc(&mp->m_sb)) 626 return; 627 628 fa = xfs_agfl_verify(bp); 629 if (fa) { 630 xfs_verifier_error(bp, -EFSCORRUPTED, fa); 631 return; 632 } 633 634 if (bip) 635 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn); 636 637 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF); 638 } 639 640 const struct xfs_buf_ops xfs_agfl_buf_ops = { 641 .name = "xfs_agfl", 642 .magic = { cpu_to_be32(XFS_AGFL_MAGIC), cpu_to_be32(XFS_AGFL_MAGIC) }, 643 .verify_read = xfs_agfl_read_verify, 644 .verify_write = xfs_agfl_write_verify, 645 .verify_struct = xfs_agfl_verify, 646 }; 647 648 /* 649 * Read in the allocation group free block array. 650 */ 651 int /* error */ 652 xfs_alloc_read_agfl( 653 xfs_mount_t *mp, /* mount point structure */ 654 xfs_trans_t *tp, /* transaction pointer */ 655 xfs_agnumber_t agno, /* allocation group number */ 656 xfs_buf_t **bpp) /* buffer for the ag free block array */ 657 { 658 xfs_buf_t *bp; /* return value */ 659 int error; 660 661 ASSERT(agno != NULLAGNUMBER); 662 error = xfs_trans_read_buf( 663 mp, tp, mp->m_ddev_targp, 664 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)), 665 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops); 666 if (error) 667 return error; 668 xfs_buf_set_ref(bp, XFS_AGFL_REF); 669 *bpp = bp; 670 return 0; 671 } 672 673 STATIC int 674 xfs_alloc_update_counters( 675 struct xfs_trans *tp, 676 struct xfs_perag *pag, 677 struct xfs_buf *agbp, 678 long len) 679 { 680 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); 681 682 pag->pagf_freeblks += len; 683 be32_add_cpu(&agf->agf_freeblks, len); 684 685 xfs_trans_agblocks_delta(tp, len); 686 if (unlikely(be32_to_cpu(agf->agf_freeblks) > 687 be32_to_cpu(agf->agf_length))) 688 return -EFSCORRUPTED; 689 690 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS); 691 return 0; 692 } 693 694 /* 695 * Allocation group level functions. 696 */ 697 698 /* 699 * Deal with the case where only small freespaces remain. Either return the 700 * contents of the last freespace record, or allocate space from the freelist if 701 * there is nothing in the tree. 702 */ 703 STATIC int /* error */ 704 xfs_alloc_ag_vextent_small( 705 struct xfs_alloc_arg *args, /* allocation argument structure */ 706 struct xfs_btree_cur *ccur, /* optional by-size cursor */ 707 xfs_agblock_t *fbnop, /* result block number */ 708 xfs_extlen_t *flenp, /* result length */ 709 int *stat) /* status: 0-freelist, 1-normal/none */ 710 { 711 int error = 0; 712 xfs_agblock_t fbno = NULLAGBLOCK; 713 xfs_extlen_t flen = 0; 714 int i = 0; 715 716 /* 717 * If a cntbt cursor is provided, try to allocate the largest record in 718 * the tree. Try the AGFL if the cntbt is empty, otherwise fail the 719 * allocation. Make sure to respect minleft even when pulling from the 720 * freelist. 721 */ 722 if (ccur) 723 error = xfs_btree_decrement(ccur, 0, &i); 724 if (error) 725 goto error; 726 if (i) { 727 error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i); 728 if (error) 729 goto error; 730 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error); 731 goto out; 732 } 733 734 if (args->minlen != 1 || args->alignment != 1 || 735 args->resv == XFS_AG_RESV_AGFL || 736 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount) <= 737 args->minleft)) 738 goto out; 739 740 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0); 741 if (error) 742 goto error; 743 if (fbno == NULLAGBLOCK) 744 goto out; 745 746 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1, 747 xfs_alloc_allow_busy_reuse(args->datatype)); 748 749 if (xfs_alloc_is_userdata(args->datatype)) { 750 struct xfs_buf *bp; 751 752 bp = xfs_btree_get_bufs(args->mp, args->tp, args->agno, fbno); 753 if (!bp) { 754 error = -EFSCORRUPTED; 755 goto error; 756 } 757 xfs_trans_binval(args->tp, bp); 758 } 759 *fbnop = args->agbno = fbno; 760 *flenp = args->len = 1; 761 XFS_WANT_CORRUPTED_GOTO(args->mp, 762 fbno < be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length), 763 error); 764 args->wasfromfl = 1; 765 trace_xfs_alloc_small_freelist(args); 766 767 /* 768 * If we're feeding an AGFL block to something that doesn't live in the 769 * free space, we need to clear out the OWN_AG rmap. 770 */ 771 error = xfs_rmap_free(args->tp, args->agbp, args->agno, fbno, 1, 772 &XFS_RMAP_OINFO_AG); 773 if (error) 774 goto error; 775 776 *stat = 0; 777 return 0; 778 779 out: 780 /* 781 * Can't do the allocation, give up. 782 */ 783 if (flen < args->minlen) { 784 args->agbno = NULLAGBLOCK; 785 trace_xfs_alloc_small_notenough(args); 786 flen = 0; 787 } 788 *fbnop = fbno; 789 *flenp = flen; 790 *stat = 1; 791 trace_xfs_alloc_small_done(args); 792 return 0; 793 794 error: 795 trace_xfs_alloc_small_error(args); 796 return error; 797 } 798 799 /* 800 * Allocate a variable extent in the allocation group agno. 801 * Type and bno are used to determine where in the allocation group the 802 * extent will start. 803 * Extent's length (returned in *len) will be between minlen and maxlen, 804 * and of the form k * prod + mod unless there's nothing that large. 805 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. 806 */ 807 STATIC int /* error */ 808 xfs_alloc_ag_vextent( 809 xfs_alloc_arg_t *args) /* argument structure for allocation */ 810 { 811 int error=0; 812 813 ASSERT(args->minlen > 0); 814 ASSERT(args->maxlen > 0); 815 ASSERT(args->minlen <= args->maxlen); 816 ASSERT(args->mod < args->prod); 817 ASSERT(args->alignment > 0); 818 819 /* 820 * Branch to correct routine based on the type. 821 */ 822 args->wasfromfl = 0; 823 switch (args->type) { 824 case XFS_ALLOCTYPE_THIS_AG: 825 error = xfs_alloc_ag_vextent_size(args); 826 break; 827 case XFS_ALLOCTYPE_NEAR_BNO: 828 error = xfs_alloc_ag_vextent_near(args); 829 break; 830 case XFS_ALLOCTYPE_THIS_BNO: 831 error = xfs_alloc_ag_vextent_exact(args); 832 break; 833 default: 834 ASSERT(0); 835 /* NOTREACHED */ 836 } 837 838 if (error || args->agbno == NULLAGBLOCK) 839 return error; 840 841 ASSERT(args->len >= args->minlen); 842 ASSERT(args->len <= args->maxlen); 843 ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL); 844 ASSERT(args->agbno % args->alignment == 0); 845 846 /* if not file data, insert new block into the reverse map btree */ 847 if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) { 848 error = xfs_rmap_alloc(args->tp, args->agbp, args->agno, 849 args->agbno, args->len, &args->oinfo); 850 if (error) 851 return error; 852 } 853 854 if (!args->wasfromfl) { 855 error = xfs_alloc_update_counters(args->tp, args->pag, 856 args->agbp, 857 -((long)(args->len))); 858 if (error) 859 return error; 860 861 ASSERT(!xfs_extent_busy_search(args->mp, args->agno, 862 args->agbno, args->len)); 863 } 864 865 xfs_ag_resv_alloc_extent(args->pag, args->resv, args); 866 867 XFS_STATS_INC(args->mp, xs_allocx); 868 XFS_STATS_ADD(args->mp, xs_allocb, args->len); 869 return error; 870 } 871 872 /* 873 * Allocate a variable extent at exactly agno/bno. 874 * Extent's length (returned in *len) will be between minlen and maxlen, 875 * and of the form k * prod + mod unless there's nothing that large. 876 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it. 877 */ 878 STATIC int /* error */ 879 xfs_alloc_ag_vextent_exact( 880 xfs_alloc_arg_t *args) /* allocation argument structure */ 881 { 882 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */ 883 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */ 884 int error; 885 xfs_agblock_t fbno; /* start block of found extent */ 886 xfs_extlen_t flen; /* length of found extent */ 887 xfs_agblock_t tbno; /* start block of busy extent */ 888 xfs_extlen_t tlen; /* length of busy extent */ 889 xfs_agblock_t tend; /* end block of busy extent */ 890 int i; /* success/failure of operation */ 891 unsigned busy_gen; 892 893 ASSERT(args->alignment == 1); 894 895 /* 896 * Allocate/initialize a cursor for the by-number freespace btree. 897 */ 898 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 899 args->agno, XFS_BTNUM_BNO); 900 901 /* 902 * Lookup bno and minlen in the btree (minlen is irrelevant, really). 903 * Look for the closest free block <= bno, it must contain bno 904 * if any free block does. 905 */ 906 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i); 907 if (error) 908 goto error0; 909 if (!i) 910 goto not_found; 911 912 /* 913 * Grab the freespace record. 914 */ 915 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i); 916 if (error) 917 goto error0; 918 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 919 ASSERT(fbno <= args->agbno); 920 921 /* 922 * Check for overlapping busy extents. 923 */ 924 tbno = fbno; 925 tlen = flen; 926 xfs_extent_busy_trim(args, &tbno, &tlen, &busy_gen); 927 928 /* 929 * Give up if the start of the extent is busy, or the freespace isn't 930 * long enough for the minimum request. 931 */ 932 if (tbno > args->agbno) 933 goto not_found; 934 if (tlen < args->minlen) 935 goto not_found; 936 tend = tbno + tlen; 937 if (tend < args->agbno + args->minlen) 938 goto not_found; 939 940 /* 941 * End of extent will be smaller of the freespace end and the 942 * maximal requested end. 943 * 944 * Fix the length according to mod and prod if given. 945 */ 946 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen) 947 - args->agbno; 948 xfs_alloc_fix_len(args); 949 ASSERT(args->agbno + args->len <= tend); 950 951 /* 952 * We are allocating agbno for args->len 953 * Allocate/initialize a cursor for the by-size btree. 954 */ 955 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 956 args->agno, XFS_BTNUM_CNT); 957 ASSERT(args->agbno + args->len <= 958 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); 959 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno, 960 args->len, XFSA_FIXUP_BNO_OK); 961 if (error) { 962 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); 963 goto error0; 964 } 965 966 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); 967 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 968 969 args->wasfromfl = 0; 970 trace_xfs_alloc_exact_done(args); 971 return 0; 972 973 not_found: 974 /* Didn't find it, return null. */ 975 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); 976 args->agbno = NULLAGBLOCK; 977 trace_xfs_alloc_exact_notfound(args); 978 return 0; 979 980 error0: 981 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); 982 trace_xfs_alloc_exact_error(args); 983 return error; 984 } 985 986 /* 987 * Search the btree in a given direction via the search cursor and compare 988 * the records found against the good extent we've already found. 989 */ 990 STATIC int 991 xfs_alloc_find_best_extent( 992 struct xfs_alloc_arg *args, /* allocation argument structure */ 993 struct xfs_btree_cur **gcur, /* good cursor */ 994 struct xfs_btree_cur **scur, /* searching cursor */ 995 xfs_agblock_t gdiff, /* difference for search comparison */ 996 xfs_agblock_t *sbno, /* extent found by search */ 997 xfs_extlen_t *slen, /* extent length */ 998 xfs_agblock_t *sbnoa, /* aligned extent found by search */ 999 xfs_extlen_t *slena, /* aligned extent length */ 1000 int dir) /* 0 = search right, 1 = search left */ 1001 { 1002 xfs_agblock_t new; 1003 xfs_agblock_t sdiff; 1004 int error; 1005 int i; 1006 unsigned busy_gen; 1007 1008 /* The good extent is perfect, no need to search. */ 1009 if (!gdiff) 1010 goto out_use_good; 1011 1012 /* 1013 * Look until we find a better one, run out of space or run off the end. 1014 */ 1015 do { 1016 error = xfs_alloc_get_rec(*scur, sbno, slen, &i); 1017 if (error) 1018 goto error0; 1019 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1020 xfs_alloc_compute_aligned(args, *sbno, *slen, 1021 sbnoa, slena, &busy_gen); 1022 1023 /* 1024 * The good extent is closer than this one. 1025 */ 1026 if (!dir) { 1027 if (*sbnoa > args->max_agbno) 1028 goto out_use_good; 1029 if (*sbnoa >= args->agbno + gdiff) 1030 goto out_use_good; 1031 } else { 1032 if (*sbnoa < args->min_agbno) 1033 goto out_use_good; 1034 if (*sbnoa <= args->agbno - gdiff) 1035 goto out_use_good; 1036 } 1037 1038 /* 1039 * Same distance, compare length and pick the best. 1040 */ 1041 if (*slena >= args->minlen) { 1042 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen); 1043 xfs_alloc_fix_len(args); 1044 1045 sdiff = xfs_alloc_compute_diff(args->agbno, args->len, 1046 args->alignment, 1047 args->datatype, *sbnoa, 1048 *slena, &new); 1049 1050 /* 1051 * Choose closer size and invalidate other cursor. 1052 */ 1053 if (sdiff < gdiff) 1054 goto out_use_search; 1055 goto out_use_good; 1056 } 1057 1058 if (!dir) 1059 error = xfs_btree_increment(*scur, 0, &i); 1060 else 1061 error = xfs_btree_decrement(*scur, 0, &i); 1062 if (error) 1063 goto error0; 1064 } while (i); 1065 1066 out_use_good: 1067 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR); 1068 *scur = NULL; 1069 return 0; 1070 1071 out_use_search: 1072 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR); 1073 *gcur = NULL; 1074 return 0; 1075 1076 error0: 1077 /* caller invalidates cursors */ 1078 return error; 1079 } 1080 1081 /* 1082 * Allocate a variable extent near bno in the allocation group agno. 1083 * Extent's length (returned in len) will be between minlen and maxlen, 1084 * and of the form k * prod + mod unless there's nothing that large. 1085 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. 1086 */ 1087 STATIC int /* error */ 1088 xfs_alloc_ag_vextent_near( 1089 xfs_alloc_arg_t *args) /* allocation argument structure */ 1090 { 1091 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */ 1092 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */ 1093 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */ 1094 xfs_agblock_t gtbno; /* start bno of right side entry */ 1095 xfs_agblock_t gtbnoa; /* aligned ... */ 1096 xfs_extlen_t gtdiff; /* difference to right side entry */ 1097 xfs_extlen_t gtlen; /* length of right side entry */ 1098 xfs_extlen_t gtlena; /* aligned ... */ 1099 xfs_agblock_t gtnew; /* useful start bno of right side */ 1100 int error; /* error code */ 1101 int i; /* result code, temporary */ 1102 int j; /* result code, temporary */ 1103 xfs_agblock_t ltbno; /* start bno of left side entry */ 1104 xfs_agblock_t ltbnoa; /* aligned ... */ 1105 xfs_extlen_t ltdiff; /* difference to left side entry */ 1106 xfs_extlen_t ltlen; /* length of left side entry */ 1107 xfs_extlen_t ltlena; /* aligned ... */ 1108 xfs_agblock_t ltnew; /* useful start bno of left side */ 1109 xfs_extlen_t rlen; /* length of returned extent */ 1110 bool busy; 1111 unsigned busy_gen; 1112 #ifdef DEBUG 1113 /* 1114 * Randomly don't execute the first algorithm. 1115 */ 1116 int dofirst; /* set to do first algorithm */ 1117 1118 dofirst = prandom_u32() & 1; 1119 #endif 1120 1121 /* handle unitialized agbno range so caller doesn't have to */ 1122 if (!args->min_agbno && !args->max_agbno) 1123 args->max_agbno = args->mp->m_sb.sb_agblocks - 1; 1124 ASSERT(args->min_agbno <= args->max_agbno); 1125 1126 /* clamp agbno to the range if it's outside */ 1127 if (args->agbno < args->min_agbno) 1128 args->agbno = args->min_agbno; 1129 if (args->agbno > args->max_agbno) 1130 args->agbno = args->max_agbno; 1131 1132 restart: 1133 bno_cur_lt = NULL; 1134 bno_cur_gt = NULL; 1135 ltlen = 0; 1136 gtlena = 0; 1137 ltlena = 0; 1138 busy = false; 1139 1140 /* 1141 * Get a cursor for the by-size btree. 1142 */ 1143 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 1144 args->agno, XFS_BTNUM_CNT); 1145 1146 /* 1147 * See if there are any free extents as big as maxlen. 1148 */ 1149 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i))) 1150 goto error0; 1151 /* 1152 * If none, then pick up the last entry in the tree unless the 1153 * tree is empty. 1154 */ 1155 if (!i) { 1156 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno, 1157 <len, &i))) 1158 goto error0; 1159 if (i == 0 || ltlen == 0) { 1160 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1161 trace_xfs_alloc_near_noentry(args); 1162 return 0; 1163 } 1164 ASSERT(i == 1); 1165 } 1166 args->wasfromfl = 0; 1167 1168 /* 1169 * First algorithm. 1170 * If the requested extent is large wrt the freespaces available 1171 * in this a.g., then the cursor will be pointing to a btree entry 1172 * near the right edge of the tree. If it's in the last btree leaf 1173 * block, then we just examine all the entries in that block 1174 * that are big enough, and pick the best one. 1175 * This is written as a while loop so we can break out of it, 1176 * but we never loop back to the top. 1177 */ 1178 while (xfs_btree_islastblock(cnt_cur, 0)) { 1179 xfs_extlen_t bdiff; 1180 int besti=0; 1181 xfs_extlen_t blen=0; 1182 xfs_agblock_t bnew=0; 1183 1184 #ifdef DEBUG 1185 if (dofirst) 1186 break; 1187 #endif 1188 /* 1189 * Start from the entry that lookup found, sequence through 1190 * all larger free blocks. If we're actually pointing at a 1191 * record smaller than maxlen, go to the start of this block, 1192 * and skip all those smaller than minlen. 1193 */ 1194 if (ltlen || args->alignment > 1) { 1195 cnt_cur->bc_ptrs[0] = 1; 1196 do { 1197 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, 1198 <len, &i))) 1199 goto error0; 1200 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1201 if (ltlen >= args->minlen) 1202 break; 1203 if ((error = xfs_btree_increment(cnt_cur, 0, &i))) 1204 goto error0; 1205 } while (i); 1206 ASSERT(ltlen >= args->minlen); 1207 if (!i) 1208 break; 1209 } 1210 i = cnt_cur->bc_ptrs[0]; 1211 for (j = 1, blen = 0, bdiff = 0; 1212 !error && j && (blen < args->maxlen || bdiff > 0); 1213 error = xfs_btree_increment(cnt_cur, 0, &j)) { 1214 /* 1215 * For each entry, decide if it's better than 1216 * the previous best entry. 1217 */ 1218 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i))) 1219 goto error0; 1220 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1221 busy = xfs_alloc_compute_aligned(args, ltbno, ltlen, 1222 <bnoa, <lena, &busy_gen); 1223 if (ltlena < args->minlen) 1224 continue; 1225 if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno) 1226 continue; 1227 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); 1228 xfs_alloc_fix_len(args); 1229 ASSERT(args->len >= args->minlen); 1230 if (args->len < blen) 1231 continue; 1232 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, 1233 args->alignment, args->datatype, ltbnoa, 1234 ltlena, <new); 1235 if (ltnew != NULLAGBLOCK && 1236 (args->len > blen || ltdiff < bdiff)) { 1237 bdiff = ltdiff; 1238 bnew = ltnew; 1239 blen = args->len; 1240 besti = cnt_cur->bc_ptrs[0]; 1241 } 1242 } 1243 /* 1244 * It didn't work. We COULD be in a case where 1245 * there's a good record somewhere, so try again. 1246 */ 1247 if (blen == 0) 1248 break; 1249 /* 1250 * Point at the best entry, and retrieve it again. 1251 */ 1252 cnt_cur->bc_ptrs[0] = besti; 1253 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i))) 1254 goto error0; 1255 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1256 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); 1257 args->len = blen; 1258 1259 /* 1260 * We are allocating starting at bnew for blen blocks. 1261 */ 1262 args->agbno = bnew; 1263 ASSERT(bnew >= ltbno); 1264 ASSERT(bnew + blen <= ltbno + ltlen); 1265 /* 1266 * Set up a cursor for the by-bno tree. 1267 */ 1268 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, 1269 args->agbp, args->agno, XFS_BTNUM_BNO); 1270 /* 1271 * Fix up the btree entries. 1272 */ 1273 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, 1274 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK))) 1275 goto error0; 1276 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1277 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR); 1278 1279 trace_xfs_alloc_near_first(args); 1280 return 0; 1281 } 1282 /* 1283 * Second algorithm. 1284 * Search in the by-bno tree to the left and to the right 1285 * simultaneously, until in each case we find a space big enough, 1286 * or run into the edge of the tree. When we run into the edge, 1287 * we deallocate that cursor. 1288 * If both searches succeed, we compare the two spaces and pick 1289 * the better one. 1290 * With alignment, it's possible for both to fail; the upper 1291 * level algorithm that picks allocation groups for allocations 1292 * is not supposed to do this. 1293 */ 1294 /* 1295 * Allocate and initialize the cursor for the leftward search. 1296 */ 1297 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 1298 args->agno, XFS_BTNUM_BNO); 1299 /* 1300 * Lookup <= bno to find the leftward search's starting point. 1301 */ 1302 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i))) 1303 goto error0; 1304 if (!i) { 1305 /* 1306 * Didn't find anything; use this cursor for the rightward 1307 * search. 1308 */ 1309 bno_cur_gt = bno_cur_lt; 1310 bno_cur_lt = NULL; 1311 } 1312 /* 1313 * Found something. Duplicate the cursor for the rightward search. 1314 */ 1315 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt))) 1316 goto error0; 1317 /* 1318 * Increment the cursor, so we will point at the entry just right 1319 * of the leftward entry if any, or to the leftmost entry. 1320 */ 1321 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i))) 1322 goto error0; 1323 if (!i) { 1324 /* 1325 * It failed, there are no rightward entries. 1326 */ 1327 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR); 1328 bno_cur_gt = NULL; 1329 } 1330 /* 1331 * Loop going left with the leftward cursor, right with the 1332 * rightward cursor, until either both directions give up or 1333 * we find an entry at least as big as minlen. 1334 */ 1335 do { 1336 if (bno_cur_lt) { 1337 if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i))) 1338 goto error0; 1339 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1340 busy |= xfs_alloc_compute_aligned(args, ltbno, ltlen, 1341 <bnoa, <lena, &busy_gen); 1342 if (ltlena >= args->minlen && ltbnoa >= args->min_agbno) 1343 break; 1344 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i))) 1345 goto error0; 1346 if (!i || ltbnoa < args->min_agbno) { 1347 xfs_btree_del_cursor(bno_cur_lt, 1348 XFS_BTREE_NOERROR); 1349 bno_cur_lt = NULL; 1350 } 1351 } 1352 if (bno_cur_gt) { 1353 if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i))) 1354 goto error0; 1355 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1356 busy |= xfs_alloc_compute_aligned(args, gtbno, gtlen, 1357 >bnoa, >lena, &busy_gen); 1358 if (gtlena >= args->minlen && gtbnoa <= args->max_agbno) 1359 break; 1360 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i))) 1361 goto error0; 1362 if (!i || gtbnoa > args->max_agbno) { 1363 xfs_btree_del_cursor(bno_cur_gt, 1364 XFS_BTREE_NOERROR); 1365 bno_cur_gt = NULL; 1366 } 1367 } 1368 } while (bno_cur_lt || bno_cur_gt); 1369 1370 /* 1371 * Got both cursors still active, need to find better entry. 1372 */ 1373 if (bno_cur_lt && bno_cur_gt) { 1374 if (ltlena >= args->minlen) { 1375 /* 1376 * Left side is good, look for a right side entry. 1377 */ 1378 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); 1379 xfs_alloc_fix_len(args); 1380 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, 1381 args->alignment, args->datatype, ltbnoa, 1382 ltlena, <new); 1383 1384 error = xfs_alloc_find_best_extent(args, 1385 &bno_cur_lt, &bno_cur_gt, 1386 ltdiff, >bno, >len, 1387 >bnoa, >lena, 1388 0 /* search right */); 1389 } else { 1390 ASSERT(gtlena >= args->minlen); 1391 1392 /* 1393 * Right side is good, look for a left side entry. 1394 */ 1395 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen); 1396 xfs_alloc_fix_len(args); 1397 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len, 1398 args->alignment, args->datatype, gtbnoa, 1399 gtlena, >new); 1400 1401 error = xfs_alloc_find_best_extent(args, 1402 &bno_cur_gt, &bno_cur_lt, 1403 gtdiff, <bno, <len, 1404 <bnoa, <lena, 1405 1 /* search left */); 1406 } 1407 1408 if (error) 1409 goto error0; 1410 } 1411 1412 /* 1413 * If we couldn't get anything, give up. 1414 */ 1415 if (bno_cur_lt == NULL && bno_cur_gt == NULL) { 1416 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1417 1418 if (busy) { 1419 trace_xfs_alloc_near_busy(args); 1420 xfs_extent_busy_flush(args->mp, args->pag, busy_gen); 1421 goto restart; 1422 } 1423 trace_xfs_alloc_size_neither(args); 1424 args->agbno = NULLAGBLOCK; 1425 return 0; 1426 } 1427 1428 /* 1429 * At this point we have selected a freespace entry, either to the 1430 * left or to the right. If it's on the right, copy all the 1431 * useful variables to the "left" set so we only have one 1432 * copy of this code. 1433 */ 1434 if (bno_cur_gt) { 1435 bno_cur_lt = bno_cur_gt; 1436 bno_cur_gt = NULL; 1437 ltbno = gtbno; 1438 ltbnoa = gtbnoa; 1439 ltlen = gtlen; 1440 ltlena = gtlena; 1441 j = 1; 1442 } else 1443 j = 0; 1444 1445 /* 1446 * Fix up the length and compute the useful address. 1447 */ 1448 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); 1449 xfs_alloc_fix_len(args); 1450 rlen = args->len; 1451 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, 1452 args->datatype, ltbnoa, ltlena, <new); 1453 ASSERT(ltnew >= ltbno); 1454 ASSERT(ltnew + rlen <= ltbnoa + ltlena); 1455 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); 1456 ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno); 1457 args->agbno = ltnew; 1458 1459 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen, 1460 ltnew, rlen, XFSA_FIXUP_BNO_OK))) 1461 goto error0; 1462 1463 if (j) 1464 trace_xfs_alloc_near_greater(args); 1465 else 1466 trace_xfs_alloc_near_lesser(args); 1467 1468 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1469 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR); 1470 return 0; 1471 1472 error0: 1473 trace_xfs_alloc_near_error(args); 1474 if (cnt_cur != NULL) 1475 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); 1476 if (bno_cur_lt != NULL) 1477 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR); 1478 if (bno_cur_gt != NULL) 1479 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR); 1480 return error; 1481 } 1482 1483 /* 1484 * Allocate a variable extent anywhere in the allocation group agno. 1485 * Extent's length (returned in len) will be between minlen and maxlen, 1486 * and of the form k * prod + mod unless there's nothing that large. 1487 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. 1488 */ 1489 STATIC int /* error */ 1490 xfs_alloc_ag_vextent_size( 1491 xfs_alloc_arg_t *args) /* allocation argument structure */ 1492 { 1493 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */ 1494 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */ 1495 int error; /* error result */ 1496 xfs_agblock_t fbno; /* start of found freespace */ 1497 xfs_extlen_t flen; /* length of found freespace */ 1498 int i; /* temp status variable */ 1499 xfs_agblock_t rbno; /* returned block number */ 1500 xfs_extlen_t rlen; /* length of returned extent */ 1501 bool busy; 1502 unsigned busy_gen; 1503 1504 restart: 1505 /* 1506 * Allocate and initialize a cursor for the by-size btree. 1507 */ 1508 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 1509 args->agno, XFS_BTNUM_CNT); 1510 bno_cur = NULL; 1511 busy = false; 1512 1513 /* 1514 * Look for an entry >= maxlen+alignment-1 blocks. 1515 */ 1516 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, 1517 args->maxlen + args->alignment - 1, &i))) 1518 goto error0; 1519 1520 /* 1521 * If none then we have to settle for a smaller extent. In the case that 1522 * there are no large extents, this will return the last entry in the 1523 * tree unless the tree is empty. In the case that there are only busy 1524 * large extents, this will return the largest small extent unless there 1525 * are no smaller extents available. 1526 */ 1527 if (!i) { 1528 error = xfs_alloc_ag_vextent_small(args, cnt_cur, 1529 &fbno, &flen, &i); 1530 if (error) 1531 goto error0; 1532 if (i == 0 || flen == 0) { 1533 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1534 trace_xfs_alloc_size_noentry(args); 1535 return 0; 1536 } 1537 ASSERT(i == 1); 1538 busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno, 1539 &rlen, &busy_gen); 1540 } else { 1541 /* 1542 * Search for a non-busy extent that is large enough. 1543 */ 1544 for (;;) { 1545 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i); 1546 if (error) 1547 goto error0; 1548 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1549 1550 busy = xfs_alloc_compute_aligned(args, fbno, flen, 1551 &rbno, &rlen, &busy_gen); 1552 1553 if (rlen >= args->maxlen) 1554 break; 1555 1556 error = xfs_btree_increment(cnt_cur, 0, &i); 1557 if (error) 1558 goto error0; 1559 if (i == 0) { 1560 /* 1561 * Our only valid extents must have been busy. 1562 * Make it unbusy by forcing the log out and 1563 * retrying. 1564 */ 1565 xfs_btree_del_cursor(cnt_cur, 1566 XFS_BTREE_NOERROR); 1567 trace_xfs_alloc_size_busy(args); 1568 xfs_extent_busy_flush(args->mp, 1569 args->pag, busy_gen); 1570 goto restart; 1571 } 1572 } 1573 } 1574 1575 /* 1576 * In the first case above, we got the last entry in the 1577 * by-size btree. Now we check to see if the space hits maxlen 1578 * once aligned; if not, we search left for something better. 1579 * This can't happen in the second case above. 1580 */ 1581 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen); 1582 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 || 1583 (rlen <= flen && rbno + rlen <= fbno + flen), error0); 1584 if (rlen < args->maxlen) { 1585 xfs_agblock_t bestfbno; 1586 xfs_extlen_t bestflen; 1587 xfs_agblock_t bestrbno; 1588 xfs_extlen_t bestrlen; 1589 1590 bestrlen = rlen; 1591 bestrbno = rbno; 1592 bestflen = flen; 1593 bestfbno = fbno; 1594 for (;;) { 1595 if ((error = xfs_btree_decrement(cnt_cur, 0, &i))) 1596 goto error0; 1597 if (i == 0) 1598 break; 1599 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, 1600 &i))) 1601 goto error0; 1602 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1603 if (flen < bestrlen) 1604 break; 1605 busy = xfs_alloc_compute_aligned(args, fbno, flen, 1606 &rbno, &rlen, &busy_gen); 1607 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen); 1608 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 || 1609 (rlen <= flen && rbno + rlen <= fbno + flen), 1610 error0); 1611 if (rlen > bestrlen) { 1612 bestrlen = rlen; 1613 bestrbno = rbno; 1614 bestflen = flen; 1615 bestfbno = fbno; 1616 if (rlen == args->maxlen) 1617 break; 1618 } 1619 } 1620 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen, 1621 &i))) 1622 goto error0; 1623 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); 1624 rlen = bestrlen; 1625 rbno = bestrbno; 1626 flen = bestflen; 1627 fbno = bestfbno; 1628 } 1629 args->wasfromfl = 0; 1630 /* 1631 * Fix up the length. 1632 */ 1633 args->len = rlen; 1634 if (rlen < args->minlen) { 1635 if (busy) { 1636 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1637 trace_xfs_alloc_size_busy(args); 1638 xfs_extent_busy_flush(args->mp, args->pag, busy_gen); 1639 goto restart; 1640 } 1641 goto out_nominleft; 1642 } 1643 xfs_alloc_fix_len(args); 1644 1645 rlen = args->len; 1646 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0); 1647 /* 1648 * Allocate and initialize a cursor for the by-block tree. 1649 */ 1650 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, 1651 args->agno, XFS_BTNUM_BNO); 1652 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, 1653 rbno, rlen, XFSA_FIXUP_CNT_OK))) 1654 goto error0; 1655 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1656 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); 1657 cnt_cur = bno_cur = NULL; 1658 args->len = rlen; 1659 args->agbno = rbno; 1660 XFS_WANT_CORRUPTED_GOTO(args->mp, 1661 args->agbno + args->len <= 1662 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length), 1663 error0); 1664 trace_xfs_alloc_size_done(args); 1665 return 0; 1666 1667 error0: 1668 trace_xfs_alloc_size_error(args); 1669 if (cnt_cur) 1670 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); 1671 if (bno_cur) 1672 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); 1673 return error; 1674 1675 out_nominleft: 1676 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1677 trace_xfs_alloc_size_nominleft(args); 1678 args->agbno = NULLAGBLOCK; 1679 return 0; 1680 } 1681 1682 /* 1683 * Free the extent starting at agno/bno for length. 1684 */ 1685 STATIC int 1686 xfs_free_ag_extent( 1687 struct xfs_trans *tp, 1688 struct xfs_buf *agbp, 1689 xfs_agnumber_t agno, 1690 xfs_agblock_t bno, 1691 xfs_extlen_t len, 1692 const struct xfs_owner_info *oinfo, 1693 enum xfs_ag_resv_type type) 1694 { 1695 struct xfs_mount *mp; 1696 struct xfs_perag *pag; 1697 struct xfs_btree_cur *bno_cur; 1698 struct xfs_btree_cur *cnt_cur; 1699 xfs_agblock_t gtbno; /* start of right neighbor */ 1700 xfs_extlen_t gtlen; /* length of right neighbor */ 1701 xfs_agblock_t ltbno; /* start of left neighbor */ 1702 xfs_extlen_t ltlen; /* length of left neighbor */ 1703 xfs_agblock_t nbno; /* new starting block of freesp */ 1704 xfs_extlen_t nlen; /* new length of freespace */ 1705 int haveleft; /* have a left neighbor */ 1706 int haveright; /* have a right neighbor */ 1707 int i; 1708 int error; 1709 1710 bno_cur = cnt_cur = NULL; 1711 mp = tp->t_mountp; 1712 1713 if (!xfs_rmap_should_skip_owner_update(oinfo)) { 1714 error = xfs_rmap_free(tp, agbp, agno, bno, len, oinfo); 1715 if (error) 1716 goto error0; 1717 } 1718 1719 /* 1720 * Allocate and initialize a cursor for the by-block btree. 1721 */ 1722 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO); 1723 /* 1724 * Look for a neighboring block on the left (lower block numbers) 1725 * that is contiguous with this space. 1726 */ 1727 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft))) 1728 goto error0; 1729 if (haveleft) { 1730 /* 1731 * There is a block to our left. 1732 */ 1733 if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i))) 1734 goto error0; 1735 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1736 /* 1737 * It's not contiguous, though. 1738 */ 1739 if (ltbno + ltlen < bno) 1740 haveleft = 0; 1741 else { 1742 /* 1743 * If this failure happens the request to free this 1744 * space was invalid, it's (partly) already free. 1745 * Very bad. 1746 */ 1747 XFS_WANT_CORRUPTED_GOTO(mp, 1748 ltbno + ltlen <= bno, error0); 1749 } 1750 } 1751 /* 1752 * Look for a neighboring block on the right (higher block numbers) 1753 * that is contiguous with this space. 1754 */ 1755 if ((error = xfs_btree_increment(bno_cur, 0, &haveright))) 1756 goto error0; 1757 if (haveright) { 1758 /* 1759 * There is a block to our right. 1760 */ 1761 if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i))) 1762 goto error0; 1763 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1764 /* 1765 * It's not contiguous, though. 1766 */ 1767 if (bno + len < gtbno) 1768 haveright = 0; 1769 else { 1770 /* 1771 * If this failure happens the request to free this 1772 * space was invalid, it's (partly) already free. 1773 * Very bad. 1774 */ 1775 XFS_WANT_CORRUPTED_GOTO(mp, gtbno >= bno + len, error0); 1776 } 1777 } 1778 /* 1779 * Now allocate and initialize a cursor for the by-size tree. 1780 */ 1781 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT); 1782 /* 1783 * Have both left and right contiguous neighbors. 1784 * Merge all three into a single free block. 1785 */ 1786 if (haveleft && haveright) { 1787 /* 1788 * Delete the old by-size entry on the left. 1789 */ 1790 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))) 1791 goto error0; 1792 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1793 if ((error = xfs_btree_delete(cnt_cur, &i))) 1794 goto error0; 1795 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1796 /* 1797 * Delete the old by-size entry on the right. 1798 */ 1799 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))) 1800 goto error0; 1801 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1802 if ((error = xfs_btree_delete(cnt_cur, &i))) 1803 goto error0; 1804 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1805 /* 1806 * Delete the old by-block entry for the right block. 1807 */ 1808 if ((error = xfs_btree_delete(bno_cur, &i))) 1809 goto error0; 1810 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1811 /* 1812 * Move the by-block cursor back to the left neighbor. 1813 */ 1814 if ((error = xfs_btree_decrement(bno_cur, 0, &i))) 1815 goto error0; 1816 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1817 #ifdef DEBUG 1818 /* 1819 * Check that this is the right record: delete didn't 1820 * mangle the cursor. 1821 */ 1822 { 1823 xfs_agblock_t xxbno; 1824 xfs_extlen_t xxlen; 1825 1826 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen, 1827 &i))) 1828 goto error0; 1829 XFS_WANT_CORRUPTED_GOTO(mp, 1830 i == 1 && xxbno == ltbno && xxlen == ltlen, 1831 error0); 1832 } 1833 #endif 1834 /* 1835 * Update remaining by-block entry to the new, joined block. 1836 */ 1837 nbno = ltbno; 1838 nlen = len + ltlen + gtlen; 1839 if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) 1840 goto error0; 1841 } 1842 /* 1843 * Have only a left contiguous neighbor. 1844 * Merge it together with the new freespace. 1845 */ 1846 else if (haveleft) { 1847 /* 1848 * Delete the old by-size entry on the left. 1849 */ 1850 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))) 1851 goto error0; 1852 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1853 if ((error = xfs_btree_delete(cnt_cur, &i))) 1854 goto error0; 1855 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1856 /* 1857 * Back up the by-block cursor to the left neighbor, and 1858 * update its length. 1859 */ 1860 if ((error = xfs_btree_decrement(bno_cur, 0, &i))) 1861 goto error0; 1862 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1863 nbno = ltbno; 1864 nlen = len + ltlen; 1865 if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) 1866 goto error0; 1867 } 1868 /* 1869 * Have only a right contiguous neighbor. 1870 * Merge it together with the new freespace. 1871 */ 1872 else if (haveright) { 1873 /* 1874 * Delete the old by-size entry on the right. 1875 */ 1876 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))) 1877 goto error0; 1878 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1879 if ((error = xfs_btree_delete(cnt_cur, &i))) 1880 goto error0; 1881 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1882 /* 1883 * Update the starting block and length of the right 1884 * neighbor in the by-block tree. 1885 */ 1886 nbno = bno; 1887 nlen = len + gtlen; 1888 if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) 1889 goto error0; 1890 } 1891 /* 1892 * No contiguous neighbors. 1893 * Insert the new freespace into the by-block tree. 1894 */ 1895 else { 1896 nbno = bno; 1897 nlen = len; 1898 if ((error = xfs_btree_insert(bno_cur, &i))) 1899 goto error0; 1900 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1901 } 1902 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); 1903 bno_cur = NULL; 1904 /* 1905 * In all cases we need to insert the new freespace in the by-size tree. 1906 */ 1907 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i))) 1908 goto error0; 1909 XFS_WANT_CORRUPTED_GOTO(mp, i == 0, error0); 1910 if ((error = xfs_btree_insert(cnt_cur, &i))) 1911 goto error0; 1912 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); 1913 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); 1914 cnt_cur = NULL; 1915 1916 /* 1917 * Update the freespace totals in the ag and superblock. 1918 */ 1919 pag = xfs_perag_get(mp, agno); 1920 error = xfs_alloc_update_counters(tp, pag, agbp, len); 1921 xfs_ag_resv_free_extent(pag, type, tp, len); 1922 xfs_perag_put(pag); 1923 if (error) 1924 goto error0; 1925 1926 XFS_STATS_INC(mp, xs_freex); 1927 XFS_STATS_ADD(mp, xs_freeb, len); 1928 1929 trace_xfs_free_extent(mp, agno, bno, len, type, haveleft, haveright); 1930 1931 return 0; 1932 1933 error0: 1934 trace_xfs_free_extent(mp, agno, bno, len, type, -1, -1); 1935 if (bno_cur) 1936 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); 1937 if (cnt_cur) 1938 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); 1939 return error; 1940 } 1941 1942 /* 1943 * Visible (exported) allocation/free functions. 1944 * Some of these are used just by xfs_alloc_btree.c and this file. 1945 */ 1946 1947 /* 1948 * Compute and fill in value of m_ag_maxlevels. 1949 */ 1950 void 1951 xfs_alloc_compute_maxlevels( 1952 xfs_mount_t *mp) /* file system mount structure */ 1953 { 1954 mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr, 1955 (mp->m_sb.sb_agblocks + 1) / 2); 1956 } 1957 1958 /* 1959 * Find the length of the longest extent in an AG. The 'need' parameter 1960 * specifies how much space we're going to need for the AGFL and the 1961 * 'reserved' parameter tells us how many blocks in this AG are reserved for 1962 * other callers. 1963 */ 1964 xfs_extlen_t 1965 xfs_alloc_longest_free_extent( 1966 struct xfs_perag *pag, 1967 xfs_extlen_t need, 1968 xfs_extlen_t reserved) 1969 { 1970 xfs_extlen_t delta = 0; 1971 1972 /* 1973 * If the AGFL needs a recharge, we'll have to subtract that from the 1974 * longest extent. 1975 */ 1976 if (need > pag->pagf_flcount) 1977 delta = need - pag->pagf_flcount; 1978 1979 /* 1980 * If we cannot maintain others' reservations with space from the 1981 * not-longest freesp extents, we'll have to subtract /that/ from 1982 * the longest extent too. 1983 */ 1984 if (pag->pagf_freeblks - pag->pagf_longest < reserved) 1985 delta += reserved - (pag->pagf_freeblks - pag->pagf_longest); 1986 1987 /* 1988 * If the longest extent is long enough to satisfy all the 1989 * reservations and AGFL rules in place, we can return this extent. 1990 */ 1991 if (pag->pagf_longest > delta) 1992 return pag->pagf_longest - delta; 1993 1994 /* Otherwise, let the caller try for 1 block if there's space. */ 1995 return pag->pagf_flcount > 0 || pag->pagf_longest > 0; 1996 } 1997 1998 unsigned int 1999 xfs_alloc_min_freelist( 2000 struct xfs_mount *mp, 2001 struct xfs_perag *pag) 2002 { 2003 unsigned int min_free; 2004 2005 /* space needed by-bno freespace btree */ 2006 min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1, 2007 mp->m_ag_maxlevels); 2008 /* space needed by-size freespace btree */ 2009 min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1, 2010 mp->m_ag_maxlevels); 2011 /* space needed reverse mapping used space btree */ 2012 if (xfs_sb_version_hasrmapbt(&mp->m_sb)) 2013 min_free += min_t(unsigned int, 2014 pag->pagf_levels[XFS_BTNUM_RMAPi] + 1, 2015 mp->m_rmap_maxlevels); 2016 2017 return min_free; 2018 } 2019 2020 /* 2021 * Check if the operation we are fixing up the freelist for should go ahead or 2022 * not. If we are freeing blocks, we always allow it, otherwise the allocation 2023 * is dependent on whether the size and shape of free space available will 2024 * permit the requested allocation to take place. 2025 */ 2026 static bool 2027 xfs_alloc_space_available( 2028 struct xfs_alloc_arg *args, 2029 xfs_extlen_t min_free, 2030 int flags) 2031 { 2032 struct xfs_perag *pag = args->pag; 2033 xfs_extlen_t alloc_len, longest; 2034 xfs_extlen_t reservation; /* blocks that are still reserved */ 2035 int available; 2036 xfs_extlen_t agflcount; 2037 2038 if (flags & XFS_ALLOC_FLAG_FREEING) 2039 return true; 2040 2041 reservation = xfs_ag_resv_needed(pag, args->resv); 2042 2043 /* do we have enough contiguous free space for the allocation? */ 2044 alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop; 2045 longest = xfs_alloc_longest_free_extent(pag, min_free, reservation); 2046 if (longest < alloc_len) 2047 return false; 2048 2049 /* 2050 * Do we have enough free space remaining for the allocation? Don't 2051 * account extra agfl blocks because we are about to defer free them, 2052 * making them unavailable until the current transaction commits. 2053 */ 2054 agflcount = min_t(xfs_extlen_t, pag->pagf_flcount, min_free); 2055 available = (int)(pag->pagf_freeblks + agflcount - 2056 reservation - min_free - args->minleft); 2057 if (available < (int)max(args->total, alloc_len)) 2058 return false; 2059 2060 /* 2061 * Clamp maxlen to the amount of free space available for the actual 2062 * extent allocation. 2063 */ 2064 if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) { 2065 args->maxlen = available; 2066 ASSERT(args->maxlen > 0); 2067 ASSERT(args->maxlen >= args->minlen); 2068 } 2069 2070 return true; 2071 } 2072 2073 int 2074 xfs_free_agfl_block( 2075 struct xfs_trans *tp, 2076 xfs_agnumber_t agno, 2077 xfs_agblock_t agbno, 2078 struct xfs_buf *agbp, 2079 struct xfs_owner_info *oinfo) 2080 { 2081 int error; 2082 struct xfs_buf *bp; 2083 2084 error = xfs_free_ag_extent(tp, agbp, agno, agbno, 1, oinfo, 2085 XFS_AG_RESV_AGFL); 2086 if (error) 2087 return error; 2088 2089 bp = xfs_btree_get_bufs(tp->t_mountp, tp, agno, agbno); 2090 if (!bp) 2091 return -EFSCORRUPTED; 2092 xfs_trans_binval(tp, bp); 2093 2094 return 0; 2095 } 2096 2097 /* 2098 * Check the agfl fields of the agf for inconsistency or corruption. The purpose 2099 * is to detect an agfl header padding mismatch between current and early v5 2100 * kernels. This problem manifests as a 1-slot size difference between the 2101 * on-disk flcount and the active [first, last] range of a wrapped agfl. This 2102 * may also catch variants of agfl count corruption unrelated to padding. Either 2103 * way, we'll reset the agfl and warn the user. 2104 * 2105 * Return true if a reset is required before the agfl can be used, false 2106 * otherwise. 2107 */ 2108 static bool 2109 xfs_agfl_needs_reset( 2110 struct xfs_mount *mp, 2111 struct xfs_agf *agf) 2112 { 2113 uint32_t f = be32_to_cpu(agf->agf_flfirst); 2114 uint32_t l = be32_to_cpu(agf->agf_fllast); 2115 uint32_t c = be32_to_cpu(agf->agf_flcount); 2116 int agfl_size = xfs_agfl_size(mp); 2117 int active; 2118 2119 /* no agfl header on v4 supers */ 2120 if (!xfs_sb_version_hascrc(&mp->m_sb)) 2121 return false; 2122 2123 /* 2124 * The agf read verifier catches severe corruption of these fields. 2125 * Repeat some sanity checks to cover a packed -> unpacked mismatch if 2126 * the verifier allows it. 2127 */ 2128 if (f >= agfl_size || l >= agfl_size) 2129 return true; 2130 if (c > agfl_size) 2131 return true; 2132 2133 /* 2134 * Check consistency between the on-disk count and the active range. An 2135 * agfl padding mismatch manifests as an inconsistent flcount. 2136 */ 2137 if (c && l >= f) 2138 active = l - f + 1; 2139 else if (c) 2140 active = agfl_size - f + l + 1; 2141 else 2142 active = 0; 2143 2144 return active != c; 2145 } 2146 2147 /* 2148 * Reset the agfl to an empty state. Ignore/drop any existing blocks since the 2149 * agfl content cannot be trusted. Warn the user that a repair is required to 2150 * recover leaked blocks. 2151 * 2152 * The purpose of this mechanism is to handle filesystems affected by the agfl 2153 * header padding mismatch problem. A reset keeps the filesystem online with a 2154 * relatively minor free space accounting inconsistency rather than suffer the 2155 * inevitable crash from use of an invalid agfl block. 2156 */ 2157 static void 2158 xfs_agfl_reset( 2159 struct xfs_trans *tp, 2160 struct xfs_buf *agbp, 2161 struct xfs_perag *pag) 2162 { 2163 struct xfs_mount *mp = tp->t_mountp; 2164 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); 2165 2166 ASSERT(pag->pagf_agflreset); 2167 trace_xfs_agfl_reset(mp, agf, 0, _RET_IP_); 2168 2169 xfs_warn(mp, 2170 "WARNING: Reset corrupted AGFL on AG %u. %d blocks leaked. " 2171 "Please unmount and run xfs_repair.", 2172 pag->pag_agno, pag->pagf_flcount); 2173 2174 agf->agf_flfirst = 0; 2175 agf->agf_fllast = cpu_to_be32(xfs_agfl_size(mp) - 1); 2176 agf->agf_flcount = 0; 2177 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST | 2178 XFS_AGF_FLCOUNT); 2179 2180 pag->pagf_flcount = 0; 2181 pag->pagf_agflreset = false; 2182 } 2183 2184 /* 2185 * Defer an AGFL block free. This is effectively equivalent to 2186 * xfs_bmap_add_free() with some special handling particular to AGFL blocks. 2187 * 2188 * Deferring AGFL frees helps prevent log reservation overruns due to too many 2189 * allocation operations in a transaction. AGFL frees are prone to this problem 2190 * because for one they are always freed one at a time. Further, an immediate 2191 * AGFL block free can cause a btree join and require another block free before 2192 * the real allocation can proceed. Deferring the free disconnects freeing up 2193 * the AGFL slot from freeing the block. 2194 */ 2195 STATIC void 2196 xfs_defer_agfl_block( 2197 struct xfs_trans *tp, 2198 xfs_agnumber_t agno, 2199 xfs_fsblock_t agbno, 2200 struct xfs_owner_info *oinfo) 2201 { 2202 struct xfs_mount *mp = tp->t_mountp; 2203 struct xfs_extent_free_item *new; /* new element */ 2204 2205 ASSERT(xfs_bmap_free_item_zone != NULL); 2206 ASSERT(oinfo != NULL); 2207 2208 new = kmem_zone_alloc(xfs_bmap_free_item_zone, 0); 2209 new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno); 2210 new->xefi_blockcount = 1; 2211 new->xefi_oinfo = *oinfo; 2212 2213 trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1); 2214 2215 xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_AGFL_FREE, &new->xefi_list); 2216 } 2217 2218 /* 2219 * Decide whether to use this allocation group for this allocation. 2220 * If so, fix up the btree freelist's size. 2221 */ 2222 int /* error */ 2223 xfs_alloc_fix_freelist( 2224 struct xfs_alloc_arg *args, /* allocation argument structure */ 2225 int flags) /* XFS_ALLOC_FLAG_... */ 2226 { 2227 struct xfs_mount *mp = args->mp; 2228 struct xfs_perag *pag = args->pag; 2229 struct xfs_trans *tp = args->tp; 2230 struct xfs_buf *agbp = NULL; 2231 struct xfs_buf *agflbp = NULL; 2232 struct xfs_alloc_arg targs; /* local allocation arguments */ 2233 xfs_agblock_t bno; /* freelist block */ 2234 xfs_extlen_t need; /* total blocks needed in freelist */ 2235 int error = 0; 2236 2237 /* deferred ops (AGFL block frees) require permanent transactions */ 2238 ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); 2239 2240 if (!pag->pagf_init) { 2241 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); 2242 if (error) 2243 goto out_no_agbp; 2244 if (!pag->pagf_init) { 2245 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); 2246 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); 2247 goto out_agbp_relse; 2248 } 2249 } 2250 2251 /* 2252 * If this is a metadata preferred pag and we are user data then try 2253 * somewhere else if we are not being asked to try harder at this 2254 * point 2255 */ 2256 if (pag->pagf_metadata && xfs_alloc_is_userdata(args->datatype) && 2257 (flags & XFS_ALLOC_FLAG_TRYLOCK)) { 2258 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); 2259 goto out_agbp_relse; 2260 } 2261 2262 need = xfs_alloc_min_freelist(mp, pag); 2263 if (!xfs_alloc_space_available(args, need, flags | 2264 XFS_ALLOC_FLAG_CHECK)) 2265 goto out_agbp_relse; 2266 2267 /* 2268 * Get the a.g. freespace buffer. 2269 * Can fail if we're not blocking on locks, and it's held. 2270 */ 2271 if (!agbp) { 2272 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); 2273 if (error) 2274 goto out_no_agbp; 2275 if (!agbp) { 2276 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); 2277 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); 2278 goto out_no_agbp; 2279 } 2280 } 2281 2282 /* reset a padding mismatched agfl before final free space check */ 2283 if (pag->pagf_agflreset) 2284 xfs_agfl_reset(tp, agbp, pag); 2285 2286 /* If there isn't enough total space or single-extent, reject it. */ 2287 need = xfs_alloc_min_freelist(mp, pag); 2288 if (!xfs_alloc_space_available(args, need, flags)) 2289 goto out_agbp_relse; 2290 2291 /* 2292 * Make the freelist shorter if it's too long. 2293 * 2294 * Note that from this point onwards, we will always release the agf and 2295 * agfl buffers on error. This handles the case where we error out and 2296 * the buffers are clean or may not have been joined to the transaction 2297 * and hence need to be released manually. If they have been joined to 2298 * the transaction, then xfs_trans_brelse() will handle them 2299 * appropriately based on the recursion count and dirty state of the 2300 * buffer. 2301 * 2302 * XXX (dgc): When we have lots of free space, does this buy us 2303 * anything other than extra overhead when we need to put more blocks 2304 * back on the free list? Maybe we should only do this when space is 2305 * getting low or the AGFL is more than half full? 2306 * 2307 * The NOSHRINK flag prevents the AGFL from being shrunk if it's too 2308 * big; the NORMAP flag prevents AGFL expand/shrink operations from 2309 * updating the rmapbt. Both flags are used in xfs_repair while we're 2310 * rebuilding the rmapbt, and neither are used by the kernel. They're 2311 * both required to ensure that rmaps are correctly recorded for the 2312 * regenerated AGFL, bnobt, and cntbt. See repair/phase5.c and 2313 * repair/rmap.c in xfsprogs for details. 2314 */ 2315 memset(&targs, 0, sizeof(targs)); 2316 /* struct copy below */ 2317 if (flags & XFS_ALLOC_FLAG_NORMAP) 2318 targs.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE; 2319 else 2320 targs.oinfo = XFS_RMAP_OINFO_AG; 2321 while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) { 2322 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0); 2323 if (error) 2324 goto out_agbp_relse; 2325 2326 /* defer agfl frees */ 2327 xfs_defer_agfl_block(tp, args->agno, bno, &targs.oinfo); 2328 } 2329 2330 targs.tp = tp; 2331 targs.mp = mp; 2332 targs.agbp = agbp; 2333 targs.agno = args->agno; 2334 targs.alignment = targs.minlen = targs.prod = 1; 2335 targs.type = XFS_ALLOCTYPE_THIS_AG; 2336 targs.pag = pag; 2337 error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp); 2338 if (error) 2339 goto out_agbp_relse; 2340 2341 /* Make the freelist longer if it's too short. */ 2342 while (pag->pagf_flcount < need) { 2343 targs.agbno = 0; 2344 targs.maxlen = need - pag->pagf_flcount; 2345 targs.resv = XFS_AG_RESV_AGFL; 2346 2347 /* Allocate as many blocks as possible at once. */ 2348 error = xfs_alloc_ag_vextent(&targs); 2349 if (error) 2350 goto out_agflbp_relse; 2351 2352 /* 2353 * Stop if we run out. Won't happen if callers are obeying 2354 * the restrictions correctly. Can happen for free calls 2355 * on a completely full ag. 2356 */ 2357 if (targs.agbno == NULLAGBLOCK) { 2358 if (flags & XFS_ALLOC_FLAG_FREEING) 2359 break; 2360 goto out_agflbp_relse; 2361 } 2362 /* 2363 * Put each allocated block on the list. 2364 */ 2365 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) { 2366 error = xfs_alloc_put_freelist(tp, agbp, 2367 agflbp, bno, 0); 2368 if (error) 2369 goto out_agflbp_relse; 2370 } 2371 } 2372 xfs_trans_brelse(tp, agflbp); 2373 args->agbp = agbp; 2374 return 0; 2375 2376 out_agflbp_relse: 2377 xfs_trans_brelse(tp, agflbp); 2378 out_agbp_relse: 2379 if (agbp) 2380 xfs_trans_brelse(tp, agbp); 2381 out_no_agbp: 2382 args->agbp = NULL; 2383 return error; 2384 } 2385 2386 /* 2387 * Get a block from the freelist. 2388 * Returns with the buffer for the block gotten. 2389 */ 2390 int /* error */ 2391 xfs_alloc_get_freelist( 2392 xfs_trans_t *tp, /* transaction pointer */ 2393 xfs_buf_t *agbp, /* buffer containing the agf structure */ 2394 xfs_agblock_t *bnop, /* block address retrieved from freelist */ 2395 int btreeblk) /* destination is a AGF btree */ 2396 { 2397 xfs_agf_t *agf; /* a.g. freespace structure */ 2398 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */ 2399 xfs_agblock_t bno; /* block number returned */ 2400 __be32 *agfl_bno; 2401 int error; 2402 int logflags; 2403 xfs_mount_t *mp = tp->t_mountp; 2404 xfs_perag_t *pag; /* per allocation group data */ 2405 2406 /* 2407 * Freelist is empty, give up. 2408 */ 2409 agf = XFS_BUF_TO_AGF(agbp); 2410 if (!agf->agf_flcount) { 2411 *bnop = NULLAGBLOCK; 2412 return 0; 2413 } 2414 /* 2415 * Read the array of free blocks. 2416 */ 2417 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno), 2418 &agflbp); 2419 if (error) 2420 return error; 2421 2422 2423 /* 2424 * Get the block number and update the data structures. 2425 */ 2426 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); 2427 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]); 2428 be32_add_cpu(&agf->agf_flfirst, 1); 2429 xfs_trans_brelse(tp, agflbp); 2430 if (be32_to_cpu(agf->agf_flfirst) == xfs_agfl_size(mp)) 2431 agf->agf_flfirst = 0; 2432 2433 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); 2434 ASSERT(!pag->pagf_agflreset); 2435 be32_add_cpu(&agf->agf_flcount, -1); 2436 xfs_trans_agflist_delta(tp, -1); 2437 pag->pagf_flcount--; 2438 2439 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT; 2440 if (btreeblk) { 2441 be32_add_cpu(&agf->agf_btreeblks, 1); 2442 pag->pagf_btreeblks++; 2443 logflags |= XFS_AGF_BTREEBLKS; 2444 } 2445 xfs_perag_put(pag); 2446 2447 xfs_alloc_log_agf(tp, agbp, logflags); 2448 *bnop = bno; 2449 2450 return 0; 2451 } 2452 2453 /* 2454 * Log the given fields from the agf structure. 2455 */ 2456 void 2457 xfs_alloc_log_agf( 2458 xfs_trans_t *tp, /* transaction pointer */ 2459 xfs_buf_t *bp, /* buffer for a.g. freelist header */ 2460 int fields) /* mask of fields to be logged (XFS_AGF_...) */ 2461 { 2462 int first; /* first byte offset */ 2463 int last; /* last byte offset */ 2464 static const short offsets[] = { 2465 offsetof(xfs_agf_t, agf_magicnum), 2466 offsetof(xfs_agf_t, agf_versionnum), 2467 offsetof(xfs_agf_t, agf_seqno), 2468 offsetof(xfs_agf_t, agf_length), 2469 offsetof(xfs_agf_t, agf_roots[0]), 2470 offsetof(xfs_agf_t, agf_levels[0]), 2471 offsetof(xfs_agf_t, agf_flfirst), 2472 offsetof(xfs_agf_t, agf_fllast), 2473 offsetof(xfs_agf_t, agf_flcount), 2474 offsetof(xfs_agf_t, agf_freeblks), 2475 offsetof(xfs_agf_t, agf_longest), 2476 offsetof(xfs_agf_t, agf_btreeblks), 2477 offsetof(xfs_agf_t, agf_uuid), 2478 offsetof(xfs_agf_t, agf_rmap_blocks), 2479 offsetof(xfs_agf_t, agf_refcount_blocks), 2480 offsetof(xfs_agf_t, agf_refcount_root), 2481 offsetof(xfs_agf_t, agf_refcount_level), 2482 /* needed so that we don't log the whole rest of the structure: */ 2483 offsetof(xfs_agf_t, agf_spare64), 2484 sizeof(xfs_agf_t) 2485 }; 2486 2487 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_); 2488 2489 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF); 2490 2491 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last); 2492 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last); 2493 } 2494 2495 /* 2496 * Interface for inode allocation to force the pag data to be initialized. 2497 */ 2498 int /* error */ 2499 xfs_alloc_pagf_init( 2500 xfs_mount_t *mp, /* file system mount structure */ 2501 xfs_trans_t *tp, /* transaction pointer */ 2502 xfs_agnumber_t agno, /* allocation group number */ 2503 int flags) /* XFS_ALLOC_FLAGS_... */ 2504 { 2505 xfs_buf_t *bp; 2506 int error; 2507 2508 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp))) 2509 return error; 2510 if (bp) 2511 xfs_trans_brelse(tp, bp); 2512 return 0; 2513 } 2514 2515 /* 2516 * Put the block on the freelist for the allocation group. 2517 */ 2518 int /* error */ 2519 xfs_alloc_put_freelist( 2520 xfs_trans_t *tp, /* transaction pointer */ 2521 xfs_buf_t *agbp, /* buffer for a.g. freelist header */ 2522 xfs_buf_t *agflbp,/* buffer for a.g. free block array */ 2523 xfs_agblock_t bno, /* block being freed */ 2524 int btreeblk) /* block came from a AGF btree */ 2525 { 2526 xfs_agf_t *agf; /* a.g. freespace structure */ 2527 __be32 *blockp;/* pointer to array entry */ 2528 int error; 2529 int logflags; 2530 xfs_mount_t *mp; /* mount structure */ 2531 xfs_perag_t *pag; /* per allocation group data */ 2532 __be32 *agfl_bno; 2533 int startoff; 2534 2535 agf = XFS_BUF_TO_AGF(agbp); 2536 mp = tp->t_mountp; 2537 2538 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp, 2539 be32_to_cpu(agf->agf_seqno), &agflbp))) 2540 return error; 2541 be32_add_cpu(&agf->agf_fllast, 1); 2542 if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp)) 2543 agf->agf_fllast = 0; 2544 2545 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); 2546 ASSERT(!pag->pagf_agflreset); 2547 be32_add_cpu(&agf->agf_flcount, 1); 2548 xfs_trans_agflist_delta(tp, 1); 2549 pag->pagf_flcount++; 2550 2551 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT; 2552 if (btreeblk) { 2553 be32_add_cpu(&agf->agf_btreeblks, -1); 2554 pag->pagf_btreeblks--; 2555 logflags |= XFS_AGF_BTREEBLKS; 2556 } 2557 xfs_perag_put(pag); 2558 2559 xfs_alloc_log_agf(tp, agbp, logflags); 2560 2561 ASSERT(be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)); 2562 2563 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); 2564 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)]; 2565 *blockp = cpu_to_be32(bno); 2566 startoff = (char *)blockp - (char *)agflbp->b_addr; 2567 2568 xfs_alloc_log_agf(tp, agbp, logflags); 2569 2570 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF); 2571 xfs_trans_log_buf(tp, agflbp, startoff, 2572 startoff + sizeof(xfs_agblock_t) - 1); 2573 return 0; 2574 } 2575 2576 static xfs_failaddr_t 2577 xfs_agf_verify( 2578 struct xfs_buf *bp) 2579 { 2580 struct xfs_mount *mp = bp->b_mount; 2581 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp); 2582 2583 if (xfs_sb_version_hascrc(&mp->m_sb)) { 2584 if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid)) 2585 return __this_address; 2586 if (!xfs_log_check_lsn(mp, 2587 be64_to_cpu(XFS_BUF_TO_AGF(bp)->agf_lsn))) 2588 return __this_address; 2589 } 2590 2591 if (!xfs_verify_magic(bp, agf->agf_magicnum)) 2592 return __this_address; 2593 2594 if (!(XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) && 2595 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) && 2596 be32_to_cpu(agf->agf_flfirst) < xfs_agfl_size(mp) && 2597 be32_to_cpu(agf->agf_fllast) < xfs_agfl_size(mp) && 2598 be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp))) 2599 return __this_address; 2600 2601 if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 || 2602 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 || 2603 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS || 2604 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS) 2605 return __this_address; 2606 2607 if (xfs_sb_version_hasrmapbt(&mp->m_sb) && 2608 (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 || 2609 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)) 2610 return __this_address; 2611 2612 /* 2613 * during growfs operations, the perag is not fully initialised, 2614 * so we can't use it for any useful checking. growfs ensures we can't 2615 * use it by using uncached buffers that don't have the perag attached 2616 * so we can detect and avoid this problem. 2617 */ 2618 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno) 2619 return __this_address; 2620 2621 if (xfs_sb_version_haslazysbcount(&mp->m_sb) && 2622 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length)) 2623 return __this_address; 2624 2625 if (xfs_sb_version_hasreflink(&mp->m_sb) && 2626 (be32_to_cpu(agf->agf_refcount_level) < 1 || 2627 be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS)) 2628 return __this_address; 2629 2630 return NULL; 2631 2632 } 2633 2634 static void 2635 xfs_agf_read_verify( 2636 struct xfs_buf *bp) 2637 { 2638 struct xfs_mount *mp = bp->b_mount; 2639 xfs_failaddr_t fa; 2640 2641 if (xfs_sb_version_hascrc(&mp->m_sb) && 2642 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF)) 2643 xfs_verifier_error(bp, -EFSBADCRC, __this_address); 2644 else { 2645 fa = xfs_agf_verify(bp); 2646 if (XFS_TEST_ERROR(fa, mp, XFS_ERRTAG_ALLOC_READ_AGF)) 2647 xfs_verifier_error(bp, -EFSCORRUPTED, fa); 2648 } 2649 } 2650 2651 static void 2652 xfs_agf_write_verify( 2653 struct xfs_buf *bp) 2654 { 2655 struct xfs_mount *mp = bp->b_mount; 2656 struct xfs_buf_log_item *bip = bp->b_log_item; 2657 xfs_failaddr_t fa; 2658 2659 fa = xfs_agf_verify(bp); 2660 if (fa) { 2661 xfs_verifier_error(bp, -EFSCORRUPTED, fa); 2662 return; 2663 } 2664 2665 if (!xfs_sb_version_hascrc(&mp->m_sb)) 2666 return; 2667 2668 if (bip) 2669 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn); 2670 2671 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF); 2672 } 2673 2674 const struct xfs_buf_ops xfs_agf_buf_ops = { 2675 .name = "xfs_agf", 2676 .magic = { cpu_to_be32(XFS_AGF_MAGIC), cpu_to_be32(XFS_AGF_MAGIC) }, 2677 .verify_read = xfs_agf_read_verify, 2678 .verify_write = xfs_agf_write_verify, 2679 .verify_struct = xfs_agf_verify, 2680 }; 2681 2682 /* 2683 * Read in the allocation group header (free/alloc section). 2684 */ 2685 int /* error */ 2686 xfs_read_agf( 2687 struct xfs_mount *mp, /* mount point structure */ 2688 struct xfs_trans *tp, /* transaction pointer */ 2689 xfs_agnumber_t agno, /* allocation group number */ 2690 int flags, /* XFS_BUF_ */ 2691 struct xfs_buf **bpp) /* buffer for the ag freelist header */ 2692 { 2693 int error; 2694 2695 trace_xfs_read_agf(mp, agno); 2696 2697 ASSERT(agno != NULLAGNUMBER); 2698 error = xfs_trans_read_buf( 2699 mp, tp, mp->m_ddev_targp, 2700 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)), 2701 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops); 2702 if (error) 2703 return error; 2704 if (!*bpp) 2705 return 0; 2706 2707 ASSERT(!(*bpp)->b_error); 2708 xfs_buf_set_ref(*bpp, XFS_AGF_REF); 2709 return 0; 2710 } 2711 2712 /* 2713 * Read in the allocation group header (free/alloc section). 2714 */ 2715 int /* error */ 2716 xfs_alloc_read_agf( 2717 struct xfs_mount *mp, /* mount point structure */ 2718 struct xfs_trans *tp, /* transaction pointer */ 2719 xfs_agnumber_t agno, /* allocation group number */ 2720 int flags, /* XFS_ALLOC_FLAG_... */ 2721 struct xfs_buf **bpp) /* buffer for the ag freelist header */ 2722 { 2723 struct xfs_agf *agf; /* ag freelist header */ 2724 struct xfs_perag *pag; /* per allocation group data */ 2725 int error; 2726 2727 trace_xfs_alloc_read_agf(mp, agno); 2728 2729 ASSERT(agno != NULLAGNUMBER); 2730 error = xfs_read_agf(mp, tp, agno, 2731 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0, 2732 bpp); 2733 if (error) 2734 return error; 2735 if (!*bpp) 2736 return 0; 2737 ASSERT(!(*bpp)->b_error); 2738 2739 agf = XFS_BUF_TO_AGF(*bpp); 2740 pag = xfs_perag_get(mp, agno); 2741 if (!pag->pagf_init) { 2742 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks); 2743 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks); 2744 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount); 2745 pag->pagf_longest = be32_to_cpu(agf->agf_longest); 2746 pag->pagf_levels[XFS_BTNUM_BNOi] = 2747 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]); 2748 pag->pagf_levels[XFS_BTNUM_CNTi] = 2749 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]); 2750 pag->pagf_levels[XFS_BTNUM_RMAPi] = 2751 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]); 2752 pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level); 2753 pag->pagf_init = 1; 2754 pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf); 2755 } 2756 #ifdef DEBUG 2757 else if (!XFS_FORCED_SHUTDOWN(mp)) { 2758 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks)); 2759 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks)); 2760 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount)); 2761 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest)); 2762 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] == 2763 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi])); 2764 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] == 2765 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi])); 2766 } 2767 #endif 2768 xfs_perag_put(pag); 2769 return 0; 2770 } 2771 2772 /* 2773 * Allocate an extent (variable-size). 2774 * Depending on the allocation type, we either look in a single allocation 2775 * group or loop over the allocation groups to find the result. 2776 */ 2777 int /* error */ 2778 xfs_alloc_vextent( 2779 struct xfs_alloc_arg *args) /* allocation argument structure */ 2780 { 2781 xfs_agblock_t agsize; /* allocation group size */ 2782 int error; 2783 int flags; /* XFS_ALLOC_FLAG_... locking flags */ 2784 struct xfs_mount *mp; /* mount structure pointer */ 2785 xfs_agnumber_t sagno; /* starting allocation group number */ 2786 xfs_alloctype_t type; /* input allocation type */ 2787 int bump_rotor = 0; 2788 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */ 2789 2790 mp = args->mp; 2791 type = args->otype = args->type; 2792 args->agbno = NULLAGBLOCK; 2793 /* 2794 * Just fix this up, for the case where the last a.g. is shorter 2795 * (or there's only one a.g.) and the caller couldn't easily figure 2796 * that out (xfs_bmap_alloc). 2797 */ 2798 agsize = mp->m_sb.sb_agblocks; 2799 if (args->maxlen > agsize) 2800 args->maxlen = agsize; 2801 if (args->alignment == 0) 2802 args->alignment = 1; 2803 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount); 2804 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize); 2805 ASSERT(args->minlen <= args->maxlen); 2806 ASSERT(args->minlen <= agsize); 2807 ASSERT(args->mod < args->prod); 2808 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount || 2809 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize || 2810 args->minlen > args->maxlen || args->minlen > agsize || 2811 args->mod >= args->prod) { 2812 args->fsbno = NULLFSBLOCK; 2813 trace_xfs_alloc_vextent_badargs(args); 2814 return 0; 2815 } 2816 2817 switch (type) { 2818 case XFS_ALLOCTYPE_THIS_AG: 2819 case XFS_ALLOCTYPE_NEAR_BNO: 2820 case XFS_ALLOCTYPE_THIS_BNO: 2821 /* 2822 * These three force us into a single a.g. 2823 */ 2824 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno); 2825 args->pag = xfs_perag_get(mp, args->agno); 2826 error = xfs_alloc_fix_freelist(args, 0); 2827 if (error) { 2828 trace_xfs_alloc_vextent_nofix(args); 2829 goto error0; 2830 } 2831 if (!args->agbp) { 2832 trace_xfs_alloc_vextent_noagbp(args); 2833 break; 2834 } 2835 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno); 2836 if ((error = xfs_alloc_ag_vextent(args))) 2837 goto error0; 2838 break; 2839 case XFS_ALLOCTYPE_START_BNO: 2840 /* 2841 * Try near allocation first, then anywhere-in-ag after 2842 * the first a.g. fails. 2843 */ 2844 if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) && 2845 (mp->m_flags & XFS_MOUNT_32BITINODES)) { 2846 args->fsbno = XFS_AGB_TO_FSB(mp, 2847 ((mp->m_agfrotor / rotorstep) % 2848 mp->m_sb.sb_agcount), 0); 2849 bump_rotor = 1; 2850 } 2851 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno); 2852 args->type = XFS_ALLOCTYPE_NEAR_BNO; 2853 /* FALLTHROUGH */ 2854 case XFS_ALLOCTYPE_FIRST_AG: 2855 /* 2856 * Rotate through the allocation groups looking for a winner. 2857 */ 2858 if (type == XFS_ALLOCTYPE_FIRST_AG) { 2859 /* 2860 * Start with allocation group given by bno. 2861 */ 2862 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno); 2863 args->type = XFS_ALLOCTYPE_THIS_AG; 2864 sagno = 0; 2865 flags = 0; 2866 } else { 2867 /* 2868 * Start with the given allocation group. 2869 */ 2870 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno); 2871 flags = XFS_ALLOC_FLAG_TRYLOCK; 2872 } 2873 /* 2874 * Loop over allocation groups twice; first time with 2875 * trylock set, second time without. 2876 */ 2877 for (;;) { 2878 args->pag = xfs_perag_get(mp, args->agno); 2879 error = xfs_alloc_fix_freelist(args, flags); 2880 if (error) { 2881 trace_xfs_alloc_vextent_nofix(args); 2882 goto error0; 2883 } 2884 /* 2885 * If we get a buffer back then the allocation will fly. 2886 */ 2887 if (args->agbp) { 2888 if ((error = xfs_alloc_ag_vextent(args))) 2889 goto error0; 2890 break; 2891 } 2892 2893 trace_xfs_alloc_vextent_loopfailed(args); 2894 2895 /* 2896 * Didn't work, figure out the next iteration. 2897 */ 2898 if (args->agno == sagno && 2899 type == XFS_ALLOCTYPE_START_BNO) 2900 args->type = XFS_ALLOCTYPE_THIS_AG; 2901 /* 2902 * For the first allocation, we can try any AG to get 2903 * space. However, if we already have allocated a 2904 * block, we don't want to try AGs whose number is below 2905 * sagno. Otherwise, we may end up with out-of-order 2906 * locking of AGF, which might cause deadlock. 2907 */ 2908 if (++(args->agno) == mp->m_sb.sb_agcount) { 2909 if (args->tp->t_firstblock != NULLFSBLOCK) 2910 args->agno = sagno; 2911 else 2912 args->agno = 0; 2913 } 2914 /* 2915 * Reached the starting a.g., must either be done 2916 * or switch to non-trylock mode. 2917 */ 2918 if (args->agno == sagno) { 2919 if (flags == 0) { 2920 args->agbno = NULLAGBLOCK; 2921 trace_xfs_alloc_vextent_allfailed(args); 2922 break; 2923 } 2924 2925 flags = 0; 2926 if (type == XFS_ALLOCTYPE_START_BNO) { 2927 args->agbno = XFS_FSB_TO_AGBNO(mp, 2928 args->fsbno); 2929 args->type = XFS_ALLOCTYPE_NEAR_BNO; 2930 } 2931 } 2932 xfs_perag_put(args->pag); 2933 } 2934 if (bump_rotor) { 2935 if (args->agno == sagno) 2936 mp->m_agfrotor = (mp->m_agfrotor + 1) % 2937 (mp->m_sb.sb_agcount * rotorstep); 2938 else 2939 mp->m_agfrotor = (args->agno * rotorstep + 1) % 2940 (mp->m_sb.sb_agcount * rotorstep); 2941 } 2942 break; 2943 default: 2944 ASSERT(0); 2945 /* NOTREACHED */ 2946 } 2947 if (args->agbno == NULLAGBLOCK) 2948 args->fsbno = NULLFSBLOCK; 2949 else { 2950 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno); 2951 #ifdef DEBUG 2952 ASSERT(args->len >= args->minlen); 2953 ASSERT(args->len <= args->maxlen); 2954 ASSERT(args->agbno % args->alignment == 0); 2955 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno), 2956 args->len); 2957 #endif 2958 2959 /* Zero the extent if we were asked to do so */ 2960 if (args->datatype & XFS_ALLOC_USERDATA_ZERO) { 2961 error = xfs_zero_extent(args->ip, args->fsbno, args->len); 2962 if (error) 2963 goto error0; 2964 } 2965 2966 } 2967 xfs_perag_put(args->pag); 2968 return 0; 2969 error0: 2970 xfs_perag_put(args->pag); 2971 return error; 2972 } 2973 2974 /* Ensure that the freelist is at full capacity. */ 2975 int 2976 xfs_free_extent_fix_freelist( 2977 struct xfs_trans *tp, 2978 xfs_agnumber_t agno, 2979 struct xfs_buf **agbp) 2980 { 2981 struct xfs_alloc_arg args; 2982 int error; 2983 2984 memset(&args, 0, sizeof(struct xfs_alloc_arg)); 2985 args.tp = tp; 2986 args.mp = tp->t_mountp; 2987 args.agno = agno; 2988 2989 /* 2990 * validate that the block number is legal - the enables us to detect 2991 * and handle a silent filesystem corruption rather than crashing. 2992 */ 2993 if (args.agno >= args.mp->m_sb.sb_agcount) 2994 return -EFSCORRUPTED; 2995 2996 args.pag = xfs_perag_get(args.mp, args.agno); 2997 ASSERT(args.pag); 2998 2999 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING); 3000 if (error) 3001 goto out; 3002 3003 *agbp = args.agbp; 3004 out: 3005 xfs_perag_put(args.pag); 3006 return error; 3007 } 3008 3009 /* 3010 * Free an extent. 3011 * Just break up the extent address and hand off to xfs_free_ag_extent 3012 * after fixing up the freelist. 3013 */ 3014 int 3015 __xfs_free_extent( 3016 struct xfs_trans *tp, 3017 xfs_fsblock_t bno, 3018 xfs_extlen_t len, 3019 const struct xfs_owner_info *oinfo, 3020 enum xfs_ag_resv_type type, 3021 bool skip_discard) 3022 { 3023 struct xfs_mount *mp = tp->t_mountp; 3024 struct xfs_buf *agbp; 3025 xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, bno); 3026 xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, bno); 3027 int error; 3028 unsigned int busy_flags = 0; 3029 3030 ASSERT(len != 0); 3031 ASSERT(type != XFS_AG_RESV_AGFL); 3032 3033 if (XFS_TEST_ERROR(false, mp, 3034 XFS_ERRTAG_FREE_EXTENT)) 3035 return -EIO; 3036 3037 error = xfs_free_extent_fix_freelist(tp, agno, &agbp); 3038 if (error) 3039 return error; 3040 3041 XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err); 3042 3043 /* validate the extent size is legal now we have the agf locked */ 3044 XFS_WANT_CORRUPTED_GOTO(mp, 3045 agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length), 3046 err); 3047 3048 error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, type); 3049 if (error) 3050 goto err; 3051 3052 if (skip_discard) 3053 busy_flags |= XFS_EXTENT_BUSY_SKIP_DISCARD; 3054 xfs_extent_busy_insert(tp, agno, agbno, len, busy_flags); 3055 return 0; 3056 3057 err: 3058 xfs_trans_brelse(tp, agbp); 3059 return error; 3060 } 3061 3062 struct xfs_alloc_query_range_info { 3063 xfs_alloc_query_range_fn fn; 3064 void *priv; 3065 }; 3066 3067 /* Format btree record and pass to our callback. */ 3068 STATIC int 3069 xfs_alloc_query_range_helper( 3070 struct xfs_btree_cur *cur, 3071 union xfs_btree_rec *rec, 3072 void *priv) 3073 { 3074 struct xfs_alloc_query_range_info *query = priv; 3075 struct xfs_alloc_rec_incore irec; 3076 3077 irec.ar_startblock = be32_to_cpu(rec->alloc.ar_startblock); 3078 irec.ar_blockcount = be32_to_cpu(rec->alloc.ar_blockcount); 3079 return query->fn(cur, &irec, query->priv); 3080 } 3081 3082 /* Find all free space within a given range of blocks. */ 3083 int 3084 xfs_alloc_query_range( 3085 struct xfs_btree_cur *cur, 3086 struct xfs_alloc_rec_incore *low_rec, 3087 struct xfs_alloc_rec_incore *high_rec, 3088 xfs_alloc_query_range_fn fn, 3089 void *priv) 3090 { 3091 union xfs_btree_irec low_brec; 3092 union xfs_btree_irec high_brec; 3093 struct xfs_alloc_query_range_info query; 3094 3095 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO); 3096 low_brec.a = *low_rec; 3097 high_brec.a = *high_rec; 3098 query.priv = priv; 3099 query.fn = fn; 3100 return xfs_btree_query_range(cur, &low_brec, &high_brec, 3101 xfs_alloc_query_range_helper, &query); 3102 } 3103 3104 /* Find all free space records. */ 3105 int 3106 xfs_alloc_query_all( 3107 struct xfs_btree_cur *cur, 3108 xfs_alloc_query_range_fn fn, 3109 void *priv) 3110 { 3111 struct xfs_alloc_query_range_info query; 3112 3113 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO); 3114 query.priv = priv; 3115 query.fn = fn; 3116 return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query); 3117 } 3118 3119 /* Is there a record covering a given extent? */ 3120 int 3121 xfs_alloc_has_record( 3122 struct xfs_btree_cur *cur, 3123 xfs_agblock_t bno, 3124 xfs_extlen_t len, 3125 bool *exists) 3126 { 3127 union xfs_btree_irec low; 3128 union xfs_btree_irec high; 3129 3130 memset(&low, 0, sizeof(low)); 3131 low.a.ar_startblock = bno; 3132 memset(&high, 0xFF, sizeof(high)); 3133 high.a.ar_startblock = bno + len - 1; 3134 3135 return xfs_btree_has_record(cur, &low, &high, exists); 3136 } 3137 3138 /* 3139 * Walk all the blocks in the AGFL. The @walk_fn can return any negative 3140 * error code or XFS_ITER_*. 3141 */ 3142 int 3143 xfs_agfl_walk( 3144 struct xfs_mount *mp, 3145 struct xfs_agf *agf, 3146 struct xfs_buf *agflbp, 3147 xfs_agfl_walk_fn walk_fn, 3148 void *priv) 3149 { 3150 __be32 *agfl_bno; 3151 unsigned int i; 3152 int error; 3153 3154 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); 3155 i = be32_to_cpu(agf->agf_flfirst); 3156 3157 /* Nothing to walk in an empty AGFL. */ 3158 if (agf->agf_flcount == cpu_to_be32(0)) 3159 return 0; 3160 3161 /* Otherwise, walk from first to last, wrapping as needed. */ 3162 for (;;) { 3163 error = walk_fn(mp, be32_to_cpu(agfl_bno[i]), priv); 3164 if (error) 3165 return error; 3166 if (i == be32_to_cpu(agf->agf_fllast)) 3167 break; 3168 if (++i == xfs_agfl_size(mp)) 3169 i = 0; 3170 } 3171 3172 return 0; 3173 } 3174