1 /* 2 * Copyright (c) 2000-2006 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #include "xfs.h" 19 #include "xfs_fs.h" 20 #include "xfs_bit.h" 21 #include "xfs_log.h" 22 #include "xfs_inum.h" 23 #include "xfs_trans.h" 24 #include "xfs_sb.h" 25 #include "xfs_ag.h" 26 #include "xfs_alloc.h" 27 #include "xfs_quota.h" 28 #include "xfs_mount.h" 29 #include "xfs_bmap_btree.h" 30 #include "xfs_alloc_btree.h" 31 #include "xfs_ialloc_btree.h" 32 #include "xfs_dinode.h" 33 #include "xfs_inode.h" 34 #include "xfs_btree.h" 35 #include "xfs_bmap.h" 36 #include "xfs_rtalloc.h" 37 #include "xfs_error.h" 38 #include "xfs_itable.h" 39 #include "xfs_rw.h" 40 #include "xfs_attr.h" 41 #include "xfs_buf_item.h" 42 #include "xfs_trans_space.h" 43 #include "xfs_utils.h" 44 #include "xfs_iomap.h" 45 #include "xfs_trace.h" 46 47 48 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ 49 << mp->m_writeio_log) 50 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP 51 52 STATIC int 53 xfs_iomap_eof_align_last_fsb( 54 xfs_mount_t *mp, 55 xfs_inode_t *ip, 56 xfs_extlen_t extsize, 57 xfs_fileoff_t *last_fsb) 58 { 59 xfs_fileoff_t new_last_fsb = 0; 60 xfs_extlen_t align; 61 int eof, error; 62 63 if (XFS_IS_REALTIME_INODE(ip)) 64 ; 65 /* 66 * If mounted with the "-o swalloc" option, roundup the allocation 67 * request to a stripe width boundary if the file size is >= 68 * stripe width and we are allocating past the allocation eof. 69 */ 70 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) && 71 (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth))) 72 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth); 73 /* 74 * Roundup the allocation request to a stripe unit (m_dalign) boundary 75 * if the file size is >= stripe unit size, and we are allocating past 76 * the allocation eof. 77 */ 78 else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign))) 79 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign); 80 81 /* 82 * Always round up the allocation request to an extent boundary 83 * (when file on a real-time subvolume or has di_extsize hint). 84 */ 85 if (extsize) { 86 if (new_last_fsb) 87 align = roundup_64(new_last_fsb, extsize); 88 else 89 align = extsize; 90 new_last_fsb = roundup_64(*last_fsb, align); 91 } 92 93 if (new_last_fsb) { 94 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); 95 if (error) 96 return error; 97 if (eof) 98 *last_fsb = new_last_fsb; 99 } 100 return 0; 101 } 102 103 STATIC int 104 xfs_cmn_err_fsblock_zero( 105 xfs_inode_t *ip, 106 xfs_bmbt_irec_t *imap) 107 { 108 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount, 109 "Access to block zero in inode %llu " 110 "start_block: %llx start_off: %llx " 111 "blkcnt: %llx extent-state: %x\n", 112 (unsigned long long)ip->i_ino, 113 (unsigned long long)imap->br_startblock, 114 (unsigned long long)imap->br_startoff, 115 (unsigned long long)imap->br_blockcount, 116 imap->br_state); 117 return EFSCORRUPTED; 118 } 119 120 int 121 xfs_iomap_write_direct( 122 xfs_inode_t *ip, 123 xfs_off_t offset, 124 size_t count, 125 xfs_bmbt_irec_t *imap, 126 int nmaps) 127 { 128 xfs_mount_t *mp = ip->i_mount; 129 xfs_fileoff_t offset_fsb; 130 xfs_fileoff_t last_fsb; 131 xfs_filblks_t count_fsb, resaligned; 132 xfs_fsblock_t firstfsb; 133 xfs_extlen_t extsz, temp; 134 int nimaps; 135 int bmapi_flag; 136 int quota_flag; 137 int rt; 138 xfs_trans_t *tp; 139 xfs_bmap_free_t free_list; 140 uint qblocks, resblks, resrtextents; 141 int committed; 142 int error; 143 144 /* 145 * Make sure that the dquots are there. This doesn't hold 146 * the ilock across a disk read. 147 */ 148 error = xfs_qm_dqattach_locked(ip, 0); 149 if (error) 150 return XFS_ERROR(error); 151 152 rt = XFS_IS_REALTIME_INODE(ip); 153 extsz = xfs_get_extsz_hint(ip); 154 155 offset_fsb = XFS_B_TO_FSBT(mp, offset); 156 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 157 if ((offset + count) > ip->i_size) { 158 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); 159 if (error) 160 goto error_out; 161 } else { 162 if (nmaps && (imap->br_startblock == HOLESTARTBLOCK)) 163 last_fsb = MIN(last_fsb, (xfs_fileoff_t) 164 imap->br_blockcount + 165 imap->br_startoff); 166 } 167 count_fsb = last_fsb - offset_fsb; 168 ASSERT(count_fsb > 0); 169 170 resaligned = count_fsb; 171 if (unlikely(extsz)) { 172 if ((temp = do_mod(offset_fsb, extsz))) 173 resaligned += temp; 174 if ((temp = do_mod(resaligned, extsz))) 175 resaligned += extsz - temp; 176 } 177 178 if (unlikely(rt)) { 179 resrtextents = qblocks = resaligned; 180 resrtextents /= mp->m_sb.sb_rextsize; 181 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); 182 quota_flag = XFS_QMOPT_RES_RTBLKS; 183 } else { 184 resrtextents = 0; 185 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); 186 quota_flag = XFS_QMOPT_RES_REGBLKS; 187 } 188 189 /* 190 * Allocate and setup the transaction 191 */ 192 xfs_iunlock(ip, XFS_ILOCK_EXCL); 193 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); 194 error = xfs_trans_reserve(tp, resblks, 195 XFS_WRITE_LOG_RES(mp), resrtextents, 196 XFS_TRANS_PERM_LOG_RES, 197 XFS_WRITE_LOG_COUNT); 198 /* 199 * Check for running out of space, note: need lock to return 200 */ 201 if (error) 202 xfs_trans_cancel(tp, 0); 203 xfs_ilock(ip, XFS_ILOCK_EXCL); 204 if (error) 205 goto error_out; 206 207 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); 208 if (error) 209 goto error1; 210 211 xfs_trans_ijoin(tp, ip); 212 213 bmapi_flag = XFS_BMAPI_WRITE; 214 if (offset < ip->i_size || extsz) 215 bmapi_flag |= XFS_BMAPI_PREALLOC; 216 217 /* 218 * Issue the xfs_bmapi() call to allocate the blocks. 219 * 220 * From this point onwards we overwrite the imap pointer that the 221 * caller gave to us. 222 */ 223 xfs_bmap_init(&free_list, &firstfsb); 224 nimaps = 1; 225 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag, 226 &firstfsb, 0, imap, &nimaps, &free_list); 227 if (error) 228 goto error0; 229 230 /* 231 * Complete the transaction 232 */ 233 error = xfs_bmap_finish(&tp, &free_list, &committed); 234 if (error) 235 goto error0; 236 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 237 if (error) 238 goto error_out; 239 240 /* 241 * Copy any maps to caller's array and return any error. 242 */ 243 if (nimaps == 0) { 244 error = ENOSPC; 245 goto error_out; 246 } 247 248 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) { 249 error = xfs_cmn_err_fsblock_zero(ip, imap); 250 goto error_out; 251 } 252 253 return 0; 254 255 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */ 256 xfs_bmap_cancel(&free_list); 257 xfs_trans_unreserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); 258 259 error1: /* Just cancel transaction */ 260 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 261 262 error_out: 263 return XFS_ERROR(error); 264 } 265 266 /* 267 * If the caller is doing a write at the end of the file, then extend the 268 * allocation out to the file system's write iosize. We clean up any extra 269 * space left over when the file is closed in xfs_inactive(). 270 * 271 * If we find we already have delalloc preallocation beyond EOF, don't do more 272 * preallocation as it it not needed. 273 */ 274 STATIC int 275 xfs_iomap_eof_want_preallocate( 276 xfs_mount_t *mp, 277 xfs_inode_t *ip, 278 xfs_off_t offset, 279 size_t count, 280 xfs_bmbt_irec_t *imap, 281 int nimaps, 282 int *prealloc) 283 { 284 xfs_fileoff_t start_fsb; 285 xfs_filblks_t count_fsb; 286 xfs_fsblock_t firstblock; 287 int n, error, imaps; 288 int found_delalloc = 0; 289 290 *prealloc = 0; 291 if ((offset + count) <= ip->i_size) 292 return 0; 293 294 /* 295 * If there are any real blocks past eof, then don't 296 * do any speculative allocation. 297 */ 298 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1))); 299 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp)); 300 while (count_fsb > 0) { 301 imaps = nimaps; 302 firstblock = NULLFSBLOCK; 303 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0, 304 &firstblock, 0, imap, &imaps, NULL); 305 if (error) 306 return error; 307 for (n = 0; n < imaps; n++) { 308 if ((imap[n].br_startblock != HOLESTARTBLOCK) && 309 (imap[n].br_startblock != DELAYSTARTBLOCK)) 310 return 0; 311 start_fsb += imap[n].br_blockcount; 312 count_fsb -= imap[n].br_blockcount; 313 314 if (imap[n].br_startblock == DELAYSTARTBLOCK) 315 found_delalloc = 1; 316 } 317 } 318 if (!found_delalloc) 319 *prealloc = 1; 320 return 0; 321 } 322 323 /* 324 * If we don't have a user specified preallocation size, dynamically increase 325 * the preallocation size as the size of the file grows. Cap the maximum size 326 * at a single extent or less if the filesystem is near full. The closer the 327 * filesystem is to full, the smaller the maximum prealocation. 328 */ 329 STATIC xfs_fsblock_t 330 xfs_iomap_prealloc_size( 331 struct xfs_mount *mp, 332 struct xfs_inode *ip) 333 { 334 xfs_fsblock_t alloc_blocks = 0; 335 336 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) { 337 int shift = 0; 338 int64_t freesp; 339 340 alloc_blocks = XFS_B_TO_FSB(mp, ip->i_size); 341 alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN, 342 rounddown_pow_of_two(alloc_blocks)); 343 344 xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT); 345 freesp = mp->m_sb.sb_fdblocks; 346 if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) { 347 shift = 2; 348 if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT]) 349 shift++; 350 if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT]) 351 shift++; 352 if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT]) 353 shift++; 354 if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT]) 355 shift++; 356 } 357 if (shift) 358 alloc_blocks >>= shift; 359 } 360 361 if (alloc_blocks < mp->m_writeio_blocks) 362 alloc_blocks = mp->m_writeio_blocks; 363 364 return alloc_blocks; 365 } 366 367 int 368 xfs_iomap_write_delay( 369 xfs_inode_t *ip, 370 xfs_off_t offset, 371 size_t count, 372 xfs_bmbt_irec_t *ret_imap) 373 { 374 xfs_mount_t *mp = ip->i_mount; 375 xfs_fileoff_t offset_fsb; 376 xfs_fileoff_t last_fsb; 377 xfs_off_t aligned_offset; 378 xfs_fileoff_t ioalign; 379 xfs_fsblock_t firstblock; 380 xfs_extlen_t extsz; 381 int nimaps; 382 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS]; 383 int prealloc, flushed = 0; 384 int error; 385 386 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); 387 388 /* 389 * Make sure that the dquots are there. This doesn't hold 390 * the ilock across a disk read. 391 */ 392 error = xfs_qm_dqattach_locked(ip, 0); 393 if (error) 394 return XFS_ERROR(error); 395 396 extsz = xfs_get_extsz_hint(ip); 397 offset_fsb = XFS_B_TO_FSBT(mp, offset); 398 399 400 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count, 401 imap, XFS_WRITE_IMAPS, &prealloc); 402 if (error) 403 return error; 404 405 retry: 406 if (prealloc) { 407 xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip); 408 409 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1)); 410 ioalign = XFS_B_TO_FSBT(mp, aligned_offset); 411 last_fsb = ioalign + alloc_blocks; 412 } else { 413 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 414 } 415 416 if (prealloc || extsz) { 417 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); 418 if (error) 419 return error; 420 } 421 422 nimaps = XFS_WRITE_IMAPS; 423 firstblock = NULLFSBLOCK; 424 error = xfs_bmapi(NULL, ip, offset_fsb, 425 (xfs_filblks_t)(last_fsb - offset_fsb), 426 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE | 427 XFS_BMAPI_ENTIRE, &firstblock, 1, imap, 428 &nimaps, NULL); 429 switch (error) { 430 case 0: 431 case ENOSPC: 432 case EDQUOT: 433 break; 434 default: 435 return XFS_ERROR(error); 436 } 437 438 /* 439 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. For 440 * ENOSPC, * flush all other inodes with delalloc blocks to free up 441 * some of the excess reserved metadata space. For both cases, retry 442 * without EOF preallocation. 443 */ 444 if (nimaps == 0) { 445 trace_xfs_delalloc_enospc(ip, offset, count); 446 if (flushed) 447 return XFS_ERROR(error ? error : ENOSPC); 448 449 if (error == ENOSPC) { 450 xfs_iunlock(ip, XFS_ILOCK_EXCL); 451 xfs_flush_inodes(ip); 452 xfs_ilock(ip, XFS_ILOCK_EXCL); 453 } 454 455 flushed = 1; 456 error = 0; 457 prealloc = 0; 458 goto retry; 459 } 460 461 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip))) 462 return xfs_cmn_err_fsblock_zero(ip, &imap[0]); 463 464 *ret_imap = imap[0]; 465 return 0; 466 } 467 468 /* 469 * Pass in a delayed allocate extent, convert it to real extents; 470 * return to the caller the extent we create which maps on top of 471 * the originating callers request. 472 * 473 * Called without a lock on the inode. 474 * 475 * We no longer bother to look at the incoming map - all we have to 476 * guarantee is that whatever we allocate fills the required range. 477 */ 478 int 479 xfs_iomap_write_allocate( 480 xfs_inode_t *ip, 481 xfs_off_t offset, 482 size_t count, 483 xfs_bmbt_irec_t *imap) 484 { 485 xfs_mount_t *mp = ip->i_mount; 486 xfs_fileoff_t offset_fsb, last_block; 487 xfs_fileoff_t end_fsb, map_start_fsb; 488 xfs_fsblock_t first_block; 489 xfs_bmap_free_t free_list; 490 xfs_filblks_t count_fsb; 491 xfs_trans_t *tp; 492 int nimaps, committed; 493 int error = 0; 494 int nres; 495 496 /* 497 * Make sure that the dquots are there. 498 */ 499 error = xfs_qm_dqattach(ip, 0); 500 if (error) 501 return XFS_ERROR(error); 502 503 offset_fsb = XFS_B_TO_FSBT(mp, offset); 504 count_fsb = imap->br_blockcount; 505 map_start_fsb = imap->br_startoff; 506 507 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); 508 509 while (count_fsb != 0) { 510 /* 511 * Set up a transaction with which to allocate the 512 * backing store for the file. Do allocations in a 513 * loop until we get some space in the range we are 514 * interested in. The other space that might be allocated 515 * is in the delayed allocation extent on which we sit 516 * but before our buffer starts. 517 */ 518 519 nimaps = 0; 520 while (nimaps == 0) { 521 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); 522 tp->t_flags |= XFS_TRANS_RESERVE; 523 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); 524 error = xfs_trans_reserve(tp, nres, 525 XFS_WRITE_LOG_RES(mp), 526 0, XFS_TRANS_PERM_LOG_RES, 527 XFS_WRITE_LOG_COUNT); 528 if (error) { 529 xfs_trans_cancel(tp, 0); 530 return XFS_ERROR(error); 531 } 532 xfs_ilock(ip, XFS_ILOCK_EXCL); 533 xfs_trans_ijoin(tp, ip); 534 535 xfs_bmap_init(&free_list, &first_block); 536 537 /* 538 * it is possible that the extents have changed since 539 * we did the read call as we dropped the ilock for a 540 * while. We have to be careful about truncates or hole 541 * punchs here - we are not allowed to allocate 542 * non-delalloc blocks here. 543 * 544 * The only protection against truncation is the pages 545 * for the range we are being asked to convert are 546 * locked and hence a truncate will block on them 547 * first. 548 * 549 * As a result, if we go beyond the range we really 550 * need and hit an delalloc extent boundary followed by 551 * a hole while we have excess blocks in the map, we 552 * will fill the hole incorrectly and overrun the 553 * transaction reservation. 554 * 555 * Using a single map prevents this as we are forced to 556 * check each map we look for overlap with the desired 557 * range and abort as soon as we find it. Also, given 558 * that we only return a single map, having one beyond 559 * what we can return is probably a bit silly. 560 * 561 * We also need to check that we don't go beyond EOF; 562 * this is a truncate optimisation as a truncate sets 563 * the new file size before block on the pages we 564 * currently have locked under writeback. Because they 565 * are about to be tossed, we don't need to write them 566 * back.... 567 */ 568 nimaps = 1; 569 end_fsb = XFS_B_TO_FSB(mp, ip->i_size); 570 error = xfs_bmap_last_offset(NULL, ip, &last_block, 571 XFS_DATA_FORK); 572 if (error) 573 goto trans_cancel; 574 575 last_block = XFS_FILEOFF_MAX(last_block, end_fsb); 576 if ((map_start_fsb + count_fsb) > last_block) { 577 count_fsb = last_block - map_start_fsb; 578 if (count_fsb == 0) { 579 error = EAGAIN; 580 goto trans_cancel; 581 } 582 } 583 584 /* 585 * Go get the actual blocks. 586 * 587 * From this point onwards we overwrite the imap 588 * pointer that the caller gave to us. 589 */ 590 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb, 591 XFS_BMAPI_WRITE, &first_block, 1, 592 imap, &nimaps, &free_list); 593 if (error) 594 goto trans_cancel; 595 596 error = xfs_bmap_finish(&tp, &free_list, &committed); 597 if (error) 598 goto trans_cancel; 599 600 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 601 if (error) 602 goto error0; 603 604 xfs_iunlock(ip, XFS_ILOCK_EXCL); 605 } 606 607 /* 608 * See if we were able to allocate an extent that 609 * covers at least part of the callers request 610 */ 611 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) 612 return xfs_cmn_err_fsblock_zero(ip, imap); 613 614 if ((offset_fsb >= imap->br_startoff) && 615 (offset_fsb < (imap->br_startoff + 616 imap->br_blockcount))) { 617 XFS_STATS_INC(xs_xstrat_quick); 618 return 0; 619 } 620 621 /* 622 * So far we have not mapped the requested part of the 623 * file, just surrounding data, try again. 624 */ 625 count_fsb -= imap->br_blockcount; 626 map_start_fsb = imap->br_startoff + imap->br_blockcount; 627 } 628 629 trans_cancel: 630 xfs_bmap_cancel(&free_list); 631 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 632 error0: 633 xfs_iunlock(ip, XFS_ILOCK_EXCL); 634 return XFS_ERROR(error); 635 } 636 637 int 638 xfs_iomap_write_unwritten( 639 xfs_inode_t *ip, 640 xfs_off_t offset, 641 size_t count) 642 { 643 xfs_mount_t *mp = ip->i_mount; 644 xfs_fileoff_t offset_fsb; 645 xfs_filblks_t count_fsb; 646 xfs_filblks_t numblks_fsb; 647 xfs_fsblock_t firstfsb; 648 int nimaps; 649 xfs_trans_t *tp; 650 xfs_bmbt_irec_t imap; 651 xfs_bmap_free_t free_list; 652 uint resblks; 653 int committed; 654 int error; 655 656 trace_xfs_unwritten_convert(ip, offset, count); 657 658 offset_fsb = XFS_B_TO_FSBT(mp, offset); 659 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); 660 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); 661 662 /* 663 * Reserve enough blocks in this transaction for two complete extent 664 * btree splits. We may be converting the middle part of an unwritten 665 * extent and in this case we will insert two new extents in the btree 666 * each of which could cause a full split. 667 * 668 * This reservation amount will be used in the first call to 669 * xfs_bmbt_split() to select an AG with enough space to satisfy the 670 * rest of the operation. 671 */ 672 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; 673 674 do { 675 /* 676 * set up a transaction to convert the range of extents 677 * from unwritten to real. Do allocations in a loop until 678 * we have covered the range passed in. 679 * 680 * Note that we open code the transaction allocation here 681 * to pass KM_NOFS--we can't risk to recursing back into 682 * the filesystem here as we might be asked to write out 683 * the same inode that we complete here and might deadlock 684 * on the iolock. 685 */ 686 xfs_wait_for_freeze(mp, SB_FREEZE_TRANS); 687 tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS); 688 tp->t_flags |= XFS_TRANS_RESERVE; 689 error = xfs_trans_reserve(tp, resblks, 690 XFS_WRITE_LOG_RES(mp), 0, 691 XFS_TRANS_PERM_LOG_RES, 692 XFS_WRITE_LOG_COUNT); 693 if (error) { 694 xfs_trans_cancel(tp, 0); 695 return XFS_ERROR(error); 696 } 697 698 xfs_ilock(ip, XFS_ILOCK_EXCL); 699 xfs_trans_ijoin(tp, ip); 700 701 /* 702 * Modify the unwritten extent state of the buffer. 703 */ 704 xfs_bmap_init(&free_list, &firstfsb); 705 nimaps = 1; 706 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, 707 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb, 708 1, &imap, &nimaps, &free_list); 709 if (error) 710 goto error_on_bmapi_transaction; 711 712 error = xfs_bmap_finish(&(tp), &(free_list), &committed); 713 if (error) 714 goto error_on_bmapi_transaction; 715 716 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 717 xfs_iunlock(ip, XFS_ILOCK_EXCL); 718 if (error) 719 return XFS_ERROR(error); 720 721 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) 722 return xfs_cmn_err_fsblock_zero(ip, &imap); 723 724 if ((numblks_fsb = imap.br_blockcount) == 0) { 725 /* 726 * The numblks_fsb value should always get 727 * smaller, otherwise the loop is stuck. 728 */ 729 ASSERT(imap.br_blockcount); 730 break; 731 } 732 offset_fsb += numblks_fsb; 733 count_fsb -= numblks_fsb; 734 } while (count_fsb > 0); 735 736 return 0; 737 738 error_on_bmapi_transaction: 739 xfs_bmap_cancel(&free_list); 740 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); 741 xfs_iunlock(ip, XFS_ILOCK_EXCL); 742 return XFS_ERROR(error); 743 } 744