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_dir2.h" 27 #include "xfs_alloc.h" 28 #include "xfs_dmapi.h" 29 #include "xfs_quota.h" 30 #include "xfs_mount.h" 31 #include "xfs_bmap_btree.h" 32 #include "xfs_alloc_btree.h" 33 #include "xfs_ialloc_btree.h" 34 #include "xfs_dir2_sf.h" 35 #include "xfs_attr_sf.h" 36 #include "xfs_dinode.h" 37 #include "xfs_inode.h" 38 #include "xfs_ialloc.h" 39 #include "xfs_btree.h" 40 #include "xfs_bmap.h" 41 #include "xfs_rtalloc.h" 42 #include "xfs_error.h" 43 #include "xfs_itable.h" 44 #include "xfs_rw.h" 45 #include "xfs_acl.h" 46 #include "xfs_attr.h" 47 #include "xfs_buf_item.h" 48 #include "xfs_trans_space.h" 49 #include "xfs_utils.h" 50 #include "xfs_iomap.h" 51 52 #if defined(XFS_RW_TRACE) 53 void 54 xfs_iomap_enter_trace( 55 int tag, 56 xfs_inode_t *ip, 57 xfs_off_t offset, 58 ssize_t count) 59 { 60 if (!ip->i_rwtrace) 61 return; 62 63 ktrace_enter(ip->i_rwtrace, 64 (void *)((unsigned long)tag), 65 (void *)ip, 66 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)), 67 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)), 68 (void *)((unsigned long)((offset >> 32) & 0xffffffff)), 69 (void *)((unsigned long)(offset & 0xffffffff)), 70 (void *)((unsigned long)count), 71 (void *)((unsigned long)((ip->i_new_size >> 32) & 0xffffffff)), 72 (void *)((unsigned long)(ip->i_new_size & 0xffffffff)), 73 (void *)((unsigned long)current_pid()), 74 (void *)NULL, 75 (void *)NULL, 76 (void *)NULL, 77 (void *)NULL, 78 (void *)NULL, 79 (void *)NULL); 80 } 81 82 void 83 xfs_iomap_map_trace( 84 int tag, 85 xfs_inode_t *ip, 86 xfs_off_t offset, 87 ssize_t count, 88 xfs_iomap_t *iomapp, 89 xfs_bmbt_irec_t *imapp, 90 int flags) 91 { 92 if (!ip->i_rwtrace) 93 return; 94 95 ktrace_enter(ip->i_rwtrace, 96 (void *)((unsigned long)tag), 97 (void *)ip, 98 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)), 99 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)), 100 (void *)((unsigned long)((offset >> 32) & 0xffffffff)), 101 (void *)((unsigned long)(offset & 0xffffffff)), 102 (void *)((unsigned long)count), 103 (void *)((unsigned long)flags), 104 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)), 105 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)), 106 (void *)((unsigned long)(iomapp->iomap_delta)), 107 (void *)((unsigned long)(iomapp->iomap_bsize)), 108 (void *)((unsigned long)(iomapp->iomap_bn)), 109 (void *)(__psint_t)(imapp->br_startoff), 110 (void *)((unsigned long)(imapp->br_blockcount)), 111 (void *)(__psint_t)(imapp->br_startblock)); 112 } 113 #else 114 #define xfs_iomap_enter_trace(tag, io, offset, count) 115 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags) 116 #endif 117 118 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ 119 << mp->m_writeio_log) 120 #define XFS_STRAT_WRITE_IMAPS 2 121 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP 122 123 STATIC int 124 xfs_imap_to_bmap( 125 xfs_inode_t *ip, 126 xfs_off_t offset, 127 xfs_bmbt_irec_t *imap, 128 xfs_iomap_t *iomapp, 129 int imaps, /* Number of imap entries */ 130 int iomaps, /* Number of iomap entries */ 131 int flags) 132 { 133 xfs_mount_t *mp = ip->i_mount; 134 int pbm; 135 xfs_fsblock_t start_block; 136 137 138 for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) { 139 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff); 140 iomapp->iomap_delta = offset - iomapp->iomap_offset; 141 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount); 142 iomapp->iomap_flags = flags; 143 144 if (XFS_IS_REALTIME_INODE(ip)) { 145 iomapp->iomap_flags |= IOMAP_REALTIME; 146 iomapp->iomap_target = mp->m_rtdev_targp; 147 } else { 148 iomapp->iomap_target = mp->m_ddev_targp; 149 } 150 start_block = imap->br_startblock; 151 if (start_block == HOLESTARTBLOCK) { 152 iomapp->iomap_bn = IOMAP_DADDR_NULL; 153 iomapp->iomap_flags |= IOMAP_HOLE; 154 } else if (start_block == DELAYSTARTBLOCK) { 155 iomapp->iomap_bn = IOMAP_DADDR_NULL; 156 iomapp->iomap_flags |= IOMAP_DELAY; 157 } else { 158 iomapp->iomap_bn = xfs_fsb_to_db(ip, start_block); 159 if (ISUNWRITTEN(imap)) 160 iomapp->iomap_flags |= IOMAP_UNWRITTEN; 161 } 162 163 offset += iomapp->iomap_bsize - iomapp->iomap_delta; 164 } 165 return pbm; /* Return the number filled */ 166 } 167 168 int 169 xfs_iomap( 170 xfs_inode_t *ip, 171 xfs_off_t offset, 172 ssize_t count, 173 int flags, 174 xfs_iomap_t *iomapp, 175 int *niomaps) 176 { 177 xfs_mount_t *mp = ip->i_mount; 178 xfs_fileoff_t offset_fsb, end_fsb; 179 int error = 0; 180 int lockmode = 0; 181 xfs_bmbt_irec_t imap; 182 int nimaps = 1; 183 int bmapi_flags = 0; 184 int iomap_flags = 0; 185 186 ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG); 187 188 if (XFS_FORCED_SHUTDOWN(mp)) 189 return XFS_ERROR(EIO); 190 191 switch (flags & (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE)) { 192 case BMAPI_READ: 193 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, ip, offset, count); 194 lockmode = xfs_ilock_map_shared(ip); 195 bmapi_flags = XFS_BMAPI_ENTIRE; 196 break; 197 case BMAPI_WRITE: 198 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, ip, offset, count); 199 lockmode = XFS_ILOCK_EXCL; 200 if (flags & BMAPI_IGNSTATE) 201 bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE; 202 xfs_ilock(ip, lockmode); 203 break; 204 case BMAPI_ALLOCATE: 205 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, ip, offset, count); 206 lockmode = XFS_ILOCK_SHARED; 207 bmapi_flags = XFS_BMAPI_ENTIRE; 208 209 /* Attempt non-blocking lock */ 210 if (flags & BMAPI_TRYLOCK) { 211 if (!xfs_ilock_nowait(ip, lockmode)) 212 return XFS_ERROR(EAGAIN); 213 } else { 214 xfs_ilock(ip, lockmode); 215 } 216 break; 217 default: 218 BUG(); 219 } 220 221 ASSERT(offset <= mp->m_maxioffset); 222 if ((xfs_fsize_t)offset + count > mp->m_maxioffset) 223 count = mp->m_maxioffset - offset; 224 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); 225 offset_fsb = XFS_B_TO_FSBT(mp, offset); 226 227 error = xfs_bmapi(NULL, ip, offset_fsb, 228 (xfs_filblks_t)(end_fsb - offset_fsb), 229 bmapi_flags, NULL, 0, &imap, 230 &nimaps, NULL, NULL); 231 232 if (error) 233 goto out; 234 235 switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE)) { 236 case BMAPI_WRITE: 237 /* If we found an extent, return it */ 238 if (nimaps && 239 (imap.br_startblock != HOLESTARTBLOCK) && 240 (imap.br_startblock != DELAYSTARTBLOCK)) { 241 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, ip, 242 offset, count, iomapp, &imap, flags); 243 break; 244 } 245 246 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) { 247 error = xfs_iomap_write_direct(ip, offset, count, flags, 248 &imap, &nimaps, nimaps); 249 } else { 250 error = xfs_iomap_write_delay(ip, offset, count, flags, 251 &imap, &nimaps); 252 } 253 if (!error) { 254 xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, ip, 255 offset, count, iomapp, &imap, flags); 256 } 257 iomap_flags = IOMAP_NEW; 258 break; 259 case BMAPI_ALLOCATE: 260 /* If we found an extent, return it */ 261 xfs_iunlock(ip, lockmode); 262 lockmode = 0; 263 264 if (nimaps && !isnullstartblock(imap.br_startblock)) { 265 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, ip, 266 offset, count, iomapp, &imap, flags); 267 break; 268 } 269 270 error = xfs_iomap_write_allocate(ip, offset, count, 271 &imap, &nimaps); 272 break; 273 } 274 275 if (nimaps) { 276 *niomaps = xfs_imap_to_bmap(ip, offset, &imap, 277 iomapp, nimaps, *niomaps, iomap_flags); 278 } else if (niomaps) { 279 *niomaps = 0; 280 } 281 282 out: 283 if (lockmode) 284 xfs_iunlock(ip, lockmode); 285 return XFS_ERROR(error); 286 } 287 288 289 STATIC int 290 xfs_iomap_eof_align_last_fsb( 291 xfs_mount_t *mp, 292 xfs_inode_t *ip, 293 xfs_extlen_t extsize, 294 xfs_fileoff_t *last_fsb) 295 { 296 xfs_fileoff_t new_last_fsb = 0; 297 xfs_extlen_t align; 298 int eof, error; 299 300 if (XFS_IS_REALTIME_INODE(ip)) 301 ; 302 /* 303 * If mounted with the "-o swalloc" option, roundup the allocation 304 * request to a stripe width boundary if the file size is >= 305 * stripe width and we are allocating past the allocation eof. 306 */ 307 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) && 308 (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth))) 309 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth); 310 /* 311 * Roundup the allocation request to a stripe unit (m_dalign) boundary 312 * if the file size is >= stripe unit size, and we are allocating past 313 * the allocation eof. 314 */ 315 else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign))) 316 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign); 317 318 /* 319 * Always round up the allocation request to an extent boundary 320 * (when file on a real-time subvolume or has di_extsize hint). 321 */ 322 if (extsize) { 323 if (new_last_fsb) 324 align = roundup_64(new_last_fsb, extsize); 325 else 326 align = extsize; 327 new_last_fsb = roundup_64(*last_fsb, align); 328 } 329 330 if (new_last_fsb) { 331 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); 332 if (error) 333 return error; 334 if (eof) 335 *last_fsb = new_last_fsb; 336 } 337 return 0; 338 } 339 340 STATIC int 341 xfs_flush_space( 342 xfs_inode_t *ip, 343 int *fsynced, 344 int *ioflags) 345 { 346 switch (*fsynced) { 347 case 0: 348 if (ip->i_delayed_blks) { 349 xfs_iunlock(ip, XFS_ILOCK_EXCL); 350 xfs_flush_inode(ip); 351 xfs_ilock(ip, XFS_ILOCK_EXCL); 352 *fsynced = 1; 353 } else { 354 *ioflags |= BMAPI_SYNC; 355 *fsynced = 2; 356 } 357 return 0; 358 case 1: 359 *fsynced = 2; 360 *ioflags |= BMAPI_SYNC; 361 return 0; 362 case 2: 363 xfs_iunlock(ip, XFS_ILOCK_EXCL); 364 xfs_flush_device(ip); 365 xfs_ilock(ip, XFS_ILOCK_EXCL); 366 *fsynced = 3; 367 return 0; 368 } 369 return 1; 370 } 371 372 STATIC int 373 xfs_cmn_err_fsblock_zero( 374 xfs_inode_t *ip, 375 xfs_bmbt_irec_t *imap) 376 { 377 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount, 378 "Access to block zero in inode %llu " 379 "start_block: %llx start_off: %llx " 380 "blkcnt: %llx extent-state: %x\n", 381 (unsigned long long)ip->i_ino, 382 (unsigned long long)imap->br_startblock, 383 (unsigned long long)imap->br_startoff, 384 (unsigned long long)imap->br_blockcount, 385 imap->br_state); 386 return EFSCORRUPTED; 387 } 388 389 int 390 xfs_iomap_write_direct( 391 xfs_inode_t *ip, 392 xfs_off_t offset, 393 size_t count, 394 int flags, 395 xfs_bmbt_irec_t *ret_imap, 396 int *nmaps, 397 int found) 398 { 399 xfs_mount_t *mp = ip->i_mount; 400 xfs_fileoff_t offset_fsb; 401 xfs_fileoff_t last_fsb; 402 xfs_filblks_t count_fsb, resaligned; 403 xfs_fsblock_t firstfsb; 404 xfs_extlen_t extsz, temp; 405 int nimaps; 406 int bmapi_flag; 407 int quota_flag; 408 int rt; 409 xfs_trans_t *tp; 410 xfs_bmbt_irec_t imap; 411 xfs_bmap_free_t free_list; 412 uint qblocks, resblks, resrtextents; 413 int committed; 414 int error; 415 416 /* 417 * Make sure that the dquots are there. This doesn't hold 418 * the ilock across a disk read. 419 */ 420 error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED); 421 if (error) 422 return XFS_ERROR(error); 423 424 rt = XFS_IS_REALTIME_INODE(ip); 425 extsz = xfs_get_extsz_hint(ip); 426 427 offset_fsb = XFS_B_TO_FSBT(mp, offset); 428 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 429 if ((offset + count) > ip->i_size) { 430 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); 431 if (error) 432 goto error_out; 433 } else { 434 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) 435 last_fsb = MIN(last_fsb, (xfs_fileoff_t) 436 ret_imap->br_blockcount + 437 ret_imap->br_startoff); 438 } 439 count_fsb = last_fsb - offset_fsb; 440 ASSERT(count_fsb > 0); 441 442 resaligned = count_fsb; 443 if (unlikely(extsz)) { 444 if ((temp = do_mod(offset_fsb, extsz))) 445 resaligned += temp; 446 if ((temp = do_mod(resaligned, extsz))) 447 resaligned += extsz - temp; 448 } 449 450 if (unlikely(rt)) { 451 resrtextents = qblocks = resaligned; 452 resrtextents /= mp->m_sb.sb_rextsize; 453 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); 454 quota_flag = XFS_QMOPT_RES_RTBLKS; 455 } else { 456 resrtextents = 0; 457 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); 458 quota_flag = XFS_QMOPT_RES_REGBLKS; 459 } 460 461 /* 462 * Allocate and setup the transaction 463 */ 464 xfs_iunlock(ip, XFS_ILOCK_EXCL); 465 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); 466 error = xfs_trans_reserve(tp, resblks, 467 XFS_WRITE_LOG_RES(mp), resrtextents, 468 XFS_TRANS_PERM_LOG_RES, 469 XFS_WRITE_LOG_COUNT); 470 /* 471 * Check for running out of space, note: need lock to return 472 */ 473 if (error) 474 xfs_trans_cancel(tp, 0); 475 xfs_ilock(ip, XFS_ILOCK_EXCL); 476 if (error) 477 goto error_out; 478 479 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip, 480 qblocks, 0, quota_flag); 481 if (error) 482 goto error1; 483 484 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 485 xfs_trans_ihold(tp, ip); 486 487 bmapi_flag = XFS_BMAPI_WRITE; 488 if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz)) 489 bmapi_flag |= XFS_BMAPI_PREALLOC; 490 491 /* 492 * Issue the xfs_bmapi() call to allocate the blocks 493 */ 494 xfs_bmap_init(&free_list, &firstfsb); 495 nimaps = 1; 496 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag, 497 &firstfsb, 0, &imap, &nimaps, &free_list, NULL); 498 if (error) 499 goto error0; 500 501 /* 502 * Complete the transaction 503 */ 504 error = xfs_bmap_finish(&tp, &free_list, &committed); 505 if (error) 506 goto error0; 507 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 508 if (error) 509 goto error_out; 510 511 /* 512 * Copy any maps to caller's array and return any error. 513 */ 514 if (nimaps == 0) { 515 error = ENOSPC; 516 goto error_out; 517 } 518 519 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) { 520 error = xfs_cmn_err_fsblock_zero(ip, &imap); 521 goto error_out; 522 } 523 524 *ret_imap = imap; 525 *nmaps = 1; 526 return 0; 527 528 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */ 529 xfs_bmap_cancel(&free_list); 530 XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag); 531 532 error1: /* Just cancel transaction */ 533 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 534 *nmaps = 0; /* nothing set-up here */ 535 536 error_out: 537 return XFS_ERROR(error); 538 } 539 540 /* 541 * If the caller is doing a write at the end of the file, 542 * then extend the allocation out to the file system's write 543 * iosize. We clean up any extra space left over when the 544 * file is closed in xfs_inactive(). 545 * 546 * For sync writes, we are flushing delayed allocate space to 547 * try to make additional space available for allocation near 548 * the filesystem full boundary - preallocation hurts in that 549 * situation, of course. 550 */ 551 STATIC int 552 xfs_iomap_eof_want_preallocate( 553 xfs_mount_t *mp, 554 xfs_inode_t *ip, 555 xfs_off_t offset, 556 size_t count, 557 int ioflag, 558 xfs_bmbt_irec_t *imap, 559 int nimaps, 560 int *prealloc) 561 { 562 xfs_fileoff_t start_fsb; 563 xfs_filblks_t count_fsb; 564 xfs_fsblock_t firstblock; 565 int n, error, imaps; 566 567 *prealloc = 0; 568 if ((ioflag & BMAPI_SYNC) || (offset + count) <= ip->i_size) 569 return 0; 570 571 /* 572 * If there are any real blocks past eof, then don't 573 * do any speculative allocation. 574 */ 575 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1))); 576 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp)); 577 while (count_fsb > 0) { 578 imaps = nimaps; 579 firstblock = NULLFSBLOCK; 580 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0, 581 &firstblock, 0, imap, &imaps, NULL, NULL); 582 if (error) 583 return error; 584 for (n = 0; n < imaps; n++) { 585 if ((imap[n].br_startblock != HOLESTARTBLOCK) && 586 (imap[n].br_startblock != DELAYSTARTBLOCK)) 587 return 0; 588 start_fsb += imap[n].br_blockcount; 589 count_fsb -= imap[n].br_blockcount; 590 } 591 } 592 *prealloc = 1; 593 return 0; 594 } 595 596 int 597 xfs_iomap_write_delay( 598 xfs_inode_t *ip, 599 xfs_off_t offset, 600 size_t count, 601 int ioflag, 602 xfs_bmbt_irec_t *ret_imap, 603 int *nmaps) 604 { 605 xfs_mount_t *mp = ip->i_mount; 606 xfs_fileoff_t offset_fsb; 607 xfs_fileoff_t last_fsb; 608 xfs_off_t aligned_offset; 609 xfs_fileoff_t ioalign; 610 xfs_fsblock_t firstblock; 611 xfs_extlen_t extsz; 612 int nimaps; 613 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS]; 614 int prealloc, fsynced = 0; 615 int error; 616 617 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); 618 619 /* 620 * Make sure that the dquots are there. This doesn't hold 621 * the ilock across a disk read. 622 */ 623 error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED); 624 if (error) 625 return XFS_ERROR(error); 626 627 extsz = xfs_get_extsz_hint(ip); 628 offset_fsb = XFS_B_TO_FSBT(mp, offset); 629 630 retry: 631 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count, 632 ioflag, imap, XFS_WRITE_IMAPS, &prealloc); 633 if (error) 634 return error; 635 636 if (prealloc) { 637 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1)); 638 ioalign = XFS_B_TO_FSBT(mp, aligned_offset); 639 last_fsb = ioalign + mp->m_writeio_blocks; 640 } else { 641 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 642 } 643 644 if (prealloc || extsz) { 645 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); 646 if (error) 647 return error; 648 } 649 650 nimaps = XFS_WRITE_IMAPS; 651 firstblock = NULLFSBLOCK; 652 error = xfs_bmapi(NULL, ip, offset_fsb, 653 (xfs_filblks_t)(last_fsb - offset_fsb), 654 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE | 655 XFS_BMAPI_ENTIRE, &firstblock, 1, imap, 656 &nimaps, NULL, NULL); 657 if (error && (error != ENOSPC)) 658 return XFS_ERROR(error); 659 660 /* 661 * If bmapi returned us nothing, and if we didn't get back EDQUOT, 662 * then we must have run out of space - flush delalloc, and retry.. 663 */ 664 if (nimaps == 0) { 665 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE, 666 ip, offset, count); 667 if (xfs_flush_space(ip, &fsynced, &ioflag)) 668 return XFS_ERROR(ENOSPC); 669 670 error = 0; 671 goto retry; 672 } 673 674 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip))) 675 return xfs_cmn_err_fsblock_zero(ip, &imap[0]); 676 677 *ret_imap = imap[0]; 678 *nmaps = 1; 679 680 return 0; 681 } 682 683 /* 684 * Pass in a delayed allocate extent, convert it to real extents; 685 * return to the caller the extent we create which maps on top of 686 * the originating callers request. 687 * 688 * Called without a lock on the inode. 689 * 690 * We no longer bother to look at the incoming map - all we have to 691 * guarantee is that whatever we allocate fills the required range. 692 */ 693 int 694 xfs_iomap_write_allocate( 695 xfs_inode_t *ip, 696 xfs_off_t offset, 697 size_t count, 698 xfs_bmbt_irec_t *map, 699 int *retmap) 700 { 701 xfs_mount_t *mp = ip->i_mount; 702 xfs_fileoff_t offset_fsb, last_block; 703 xfs_fileoff_t end_fsb, map_start_fsb; 704 xfs_fsblock_t first_block; 705 xfs_bmap_free_t free_list; 706 xfs_filblks_t count_fsb; 707 xfs_bmbt_irec_t imap; 708 xfs_trans_t *tp; 709 int nimaps, committed; 710 int error = 0; 711 int nres; 712 713 *retmap = 0; 714 715 /* 716 * Make sure that the dquots are there. 717 */ 718 if ((error = XFS_QM_DQATTACH(mp, ip, 0))) 719 return XFS_ERROR(error); 720 721 offset_fsb = XFS_B_TO_FSBT(mp, offset); 722 count_fsb = map->br_blockcount; 723 map_start_fsb = map->br_startoff; 724 725 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); 726 727 while (count_fsb != 0) { 728 /* 729 * Set up a transaction with which to allocate the 730 * backing store for the file. Do allocations in a 731 * loop until we get some space in the range we are 732 * interested in. The other space that might be allocated 733 * is in the delayed allocation extent on which we sit 734 * but before our buffer starts. 735 */ 736 737 nimaps = 0; 738 while (nimaps == 0) { 739 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); 740 tp->t_flags |= XFS_TRANS_RESERVE; 741 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); 742 error = xfs_trans_reserve(tp, nres, 743 XFS_WRITE_LOG_RES(mp), 744 0, XFS_TRANS_PERM_LOG_RES, 745 XFS_WRITE_LOG_COUNT); 746 if (error) { 747 xfs_trans_cancel(tp, 0); 748 return XFS_ERROR(error); 749 } 750 xfs_ilock(ip, XFS_ILOCK_EXCL); 751 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 752 xfs_trans_ihold(tp, ip); 753 754 xfs_bmap_init(&free_list, &first_block); 755 756 /* 757 * it is possible that the extents have changed since 758 * we did the read call as we dropped the ilock for a 759 * while. We have to be careful about truncates or hole 760 * punchs here - we are not allowed to allocate 761 * non-delalloc blocks here. 762 * 763 * The only protection against truncation is the pages 764 * for the range we are being asked to convert are 765 * locked and hence a truncate will block on them 766 * first. 767 * 768 * As a result, if we go beyond the range we really 769 * need and hit an delalloc extent boundary followed by 770 * a hole while we have excess blocks in the map, we 771 * will fill the hole incorrectly and overrun the 772 * transaction reservation. 773 * 774 * Using a single map prevents this as we are forced to 775 * check each map we look for overlap with the desired 776 * range and abort as soon as we find it. Also, given 777 * that we only return a single map, having one beyond 778 * what we can return is probably a bit silly. 779 * 780 * We also need to check that we don't go beyond EOF; 781 * this is a truncate optimisation as a truncate sets 782 * the new file size before block on the pages we 783 * currently have locked under writeback. Because they 784 * are about to be tossed, we don't need to write them 785 * back.... 786 */ 787 nimaps = 1; 788 end_fsb = XFS_B_TO_FSB(mp, ip->i_size); 789 error = xfs_bmap_last_offset(NULL, ip, &last_block, 790 XFS_DATA_FORK); 791 if (error) 792 goto trans_cancel; 793 794 last_block = XFS_FILEOFF_MAX(last_block, end_fsb); 795 if ((map_start_fsb + count_fsb) > last_block) { 796 count_fsb = last_block - map_start_fsb; 797 if (count_fsb == 0) { 798 error = EAGAIN; 799 goto trans_cancel; 800 } 801 } 802 803 /* Go get the actual blocks */ 804 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb, 805 XFS_BMAPI_WRITE, &first_block, 1, 806 &imap, &nimaps, &free_list, NULL); 807 if (error) 808 goto trans_cancel; 809 810 error = xfs_bmap_finish(&tp, &free_list, &committed); 811 if (error) 812 goto trans_cancel; 813 814 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 815 if (error) 816 goto error0; 817 818 xfs_iunlock(ip, XFS_ILOCK_EXCL); 819 } 820 821 /* 822 * See if we were able to allocate an extent that 823 * covers at least part of the callers request 824 */ 825 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) 826 return xfs_cmn_err_fsblock_zero(ip, &imap); 827 828 if ((offset_fsb >= imap.br_startoff) && 829 (offset_fsb < (imap.br_startoff + 830 imap.br_blockcount))) { 831 *map = imap; 832 *retmap = 1; 833 XFS_STATS_INC(xs_xstrat_quick); 834 return 0; 835 } 836 837 /* 838 * So far we have not mapped the requested part of the 839 * file, just surrounding data, try again. 840 */ 841 count_fsb -= imap.br_blockcount; 842 map_start_fsb = imap.br_startoff + imap.br_blockcount; 843 } 844 845 trans_cancel: 846 xfs_bmap_cancel(&free_list); 847 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 848 error0: 849 xfs_iunlock(ip, XFS_ILOCK_EXCL); 850 return XFS_ERROR(error); 851 } 852 853 int 854 xfs_iomap_write_unwritten( 855 xfs_inode_t *ip, 856 xfs_off_t offset, 857 size_t count) 858 { 859 xfs_mount_t *mp = ip->i_mount; 860 xfs_fileoff_t offset_fsb; 861 xfs_filblks_t count_fsb; 862 xfs_filblks_t numblks_fsb; 863 xfs_fsblock_t firstfsb; 864 int nimaps; 865 xfs_trans_t *tp; 866 xfs_bmbt_irec_t imap; 867 xfs_bmap_free_t free_list; 868 uint resblks; 869 int committed; 870 int error; 871 872 xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN, ip, offset, count); 873 874 offset_fsb = XFS_B_TO_FSBT(mp, offset); 875 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); 876 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); 877 878 /* 879 * Reserve enough blocks in this transaction for two complete extent 880 * btree splits. We may be converting the middle part of an unwritten 881 * extent and in this case we will insert two new extents in the btree 882 * each of which could cause a full split. 883 * 884 * This reservation amount will be used in the first call to 885 * xfs_bmbt_split() to select an AG with enough space to satisfy the 886 * rest of the operation. 887 */ 888 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; 889 890 do { 891 /* 892 * set up a transaction to convert the range of extents 893 * from unwritten to real. Do allocations in a loop until 894 * we have covered the range passed in. 895 */ 896 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); 897 tp->t_flags |= XFS_TRANS_RESERVE; 898 error = xfs_trans_reserve(tp, resblks, 899 XFS_WRITE_LOG_RES(mp), 0, 900 XFS_TRANS_PERM_LOG_RES, 901 XFS_WRITE_LOG_COUNT); 902 if (error) { 903 xfs_trans_cancel(tp, 0); 904 return XFS_ERROR(error); 905 } 906 907 xfs_ilock(ip, XFS_ILOCK_EXCL); 908 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 909 xfs_trans_ihold(tp, ip); 910 911 /* 912 * Modify the unwritten extent state of the buffer. 913 */ 914 xfs_bmap_init(&free_list, &firstfsb); 915 nimaps = 1; 916 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, 917 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb, 918 1, &imap, &nimaps, &free_list, NULL); 919 if (error) 920 goto error_on_bmapi_transaction; 921 922 error = xfs_bmap_finish(&(tp), &(free_list), &committed); 923 if (error) 924 goto error_on_bmapi_transaction; 925 926 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 927 xfs_iunlock(ip, XFS_ILOCK_EXCL); 928 if (error) 929 return XFS_ERROR(error); 930 931 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) 932 return xfs_cmn_err_fsblock_zero(ip, &imap); 933 934 if ((numblks_fsb = imap.br_blockcount) == 0) { 935 /* 936 * The numblks_fsb value should always get 937 * smaller, otherwise the loop is stuck. 938 */ 939 ASSERT(imap.br_blockcount); 940 break; 941 } 942 offset_fsb += numblks_fsb; 943 count_fsb -= numblks_fsb; 944 } while (count_fsb > 0); 945 946 return 0; 947 948 error_on_bmapi_transaction: 949 xfs_bmap_cancel(&free_list); 950 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); 951 xfs_iunlock(ip, XFS_ILOCK_EXCL); 952 return XFS_ERROR(error); 953 } 954