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|XFS_EXTSIZE_WR; 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|XFS_EXTSIZE_RD; 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_fsize_t isize, 294 xfs_extlen_t extsize, 295 xfs_fileoff_t *last_fsb) 296 { 297 xfs_fileoff_t new_last_fsb = 0; 298 xfs_extlen_t align; 299 int eof, error; 300 301 if (XFS_IS_REALTIME_INODE(ip)) 302 ; 303 /* 304 * If mounted with the "-o swalloc" option, roundup the allocation 305 * request to a stripe width boundary if the file size is >= 306 * stripe width and we are allocating past the allocation eof. 307 */ 308 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) && 309 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth))) 310 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth); 311 /* 312 * Roundup the allocation request to a stripe unit (m_dalign) boundary 313 * if the file size is >= stripe unit size, and we are allocating past 314 * the allocation eof. 315 */ 316 else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign))) 317 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign); 318 319 /* 320 * Always round up the allocation request to an extent boundary 321 * (when file on a real-time subvolume or has di_extsize hint). 322 */ 323 if (extsize) { 324 if (new_last_fsb) 325 align = roundup_64(new_last_fsb, extsize); 326 else 327 align = extsize; 328 new_last_fsb = roundup_64(*last_fsb, align); 329 } 330 331 if (new_last_fsb) { 332 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); 333 if (error) 334 return error; 335 if (eof) 336 *last_fsb = new_last_fsb; 337 } 338 return 0; 339 } 340 341 STATIC int 342 xfs_flush_space( 343 xfs_inode_t *ip, 344 int *fsynced, 345 int *ioflags) 346 { 347 switch (*fsynced) { 348 case 0: 349 if (ip->i_delayed_blks) { 350 xfs_iunlock(ip, XFS_ILOCK_EXCL); 351 xfs_flush_inode(ip); 352 xfs_ilock(ip, XFS_ILOCK_EXCL); 353 *fsynced = 1; 354 } else { 355 *ioflags |= BMAPI_SYNC; 356 *fsynced = 2; 357 } 358 return 0; 359 case 1: 360 *fsynced = 2; 361 *ioflags |= BMAPI_SYNC; 362 return 0; 363 case 2: 364 xfs_iunlock(ip, XFS_ILOCK_EXCL); 365 xfs_flush_device(ip); 366 xfs_ilock(ip, XFS_ILOCK_EXCL); 367 *fsynced = 3; 368 return 0; 369 } 370 return 1; 371 } 372 373 STATIC int 374 xfs_cmn_err_fsblock_zero( 375 xfs_inode_t *ip, 376 xfs_bmbt_irec_t *imap) 377 { 378 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount, 379 "Access to block zero in inode %llu " 380 "start_block: %llx start_off: %llx " 381 "blkcnt: %llx extent-state: %x\n", 382 (unsigned long long)ip->i_ino, 383 (unsigned long long)imap->br_startblock, 384 (unsigned long long)imap->br_startoff, 385 (unsigned long long)imap->br_blockcount, 386 imap->br_state); 387 return EFSCORRUPTED; 388 } 389 390 int 391 xfs_iomap_write_direct( 392 xfs_inode_t *ip, 393 xfs_off_t offset, 394 size_t count, 395 int flags, 396 xfs_bmbt_irec_t *ret_imap, 397 int *nmaps, 398 int found) 399 { 400 xfs_mount_t *mp = ip->i_mount; 401 xfs_fileoff_t offset_fsb; 402 xfs_fileoff_t last_fsb; 403 xfs_filblks_t count_fsb, resaligned; 404 xfs_fsblock_t firstfsb; 405 xfs_extlen_t extsz, temp; 406 xfs_fsize_t isize; 407 int nimaps; 408 int bmapi_flag; 409 int quota_flag; 410 int rt; 411 xfs_trans_t *tp; 412 xfs_bmbt_irec_t imap; 413 xfs_bmap_free_t free_list; 414 uint qblocks, resblks, resrtextents; 415 int committed; 416 int error; 417 418 /* 419 * Make sure that the dquots are there. This doesn't hold 420 * the ilock across a disk read. 421 */ 422 error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED); 423 if (error) 424 return XFS_ERROR(error); 425 426 rt = XFS_IS_REALTIME_INODE(ip); 427 extsz = xfs_get_extsz_hint(ip); 428 429 isize = ip->i_size; 430 if (ip->i_new_size > isize) 431 isize = ip->i_new_size; 432 433 offset_fsb = XFS_B_TO_FSBT(mp, offset); 434 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 435 if ((offset + count) > isize) { 436 error = xfs_iomap_eof_align_last_fsb(mp, ip, isize, extsz, 437 &last_fsb); 438 if (error) 439 goto error_out; 440 } else { 441 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) 442 last_fsb = MIN(last_fsb, (xfs_fileoff_t) 443 ret_imap->br_blockcount + 444 ret_imap->br_startoff); 445 } 446 count_fsb = last_fsb - offset_fsb; 447 ASSERT(count_fsb > 0); 448 449 resaligned = count_fsb; 450 if (unlikely(extsz)) { 451 if ((temp = do_mod(offset_fsb, extsz))) 452 resaligned += temp; 453 if ((temp = do_mod(resaligned, extsz))) 454 resaligned += extsz - temp; 455 } 456 457 if (unlikely(rt)) { 458 resrtextents = qblocks = resaligned; 459 resrtextents /= mp->m_sb.sb_rextsize; 460 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); 461 quota_flag = XFS_QMOPT_RES_RTBLKS; 462 } else { 463 resrtextents = 0; 464 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); 465 quota_flag = XFS_QMOPT_RES_REGBLKS; 466 } 467 468 /* 469 * Allocate and setup the transaction 470 */ 471 xfs_iunlock(ip, XFS_ILOCK_EXCL); 472 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); 473 error = xfs_trans_reserve(tp, resblks, 474 XFS_WRITE_LOG_RES(mp), resrtextents, 475 XFS_TRANS_PERM_LOG_RES, 476 XFS_WRITE_LOG_COUNT); 477 /* 478 * Check for running out of space, note: need lock to return 479 */ 480 if (error) 481 xfs_trans_cancel(tp, 0); 482 xfs_ilock(ip, XFS_ILOCK_EXCL); 483 if (error) 484 goto error_out; 485 486 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip, 487 qblocks, 0, quota_flag); 488 if (error) 489 goto error1; 490 491 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 492 xfs_trans_ihold(tp, ip); 493 494 bmapi_flag = XFS_BMAPI_WRITE; 495 if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz)) 496 bmapi_flag |= XFS_BMAPI_PREALLOC; 497 498 /* 499 * Issue the xfs_bmapi() call to allocate the blocks 500 */ 501 XFS_BMAP_INIT(&free_list, &firstfsb); 502 nimaps = 1; 503 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag, 504 &firstfsb, 0, &imap, &nimaps, &free_list, NULL); 505 if (error) 506 goto error0; 507 508 /* 509 * Complete the transaction 510 */ 511 error = xfs_bmap_finish(&tp, &free_list, &committed); 512 if (error) 513 goto error0; 514 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 515 if (error) 516 goto error_out; 517 518 /* 519 * Copy any maps to caller's array and return any error. 520 */ 521 if (nimaps == 0) { 522 error = ENOSPC; 523 goto error_out; 524 } 525 526 if (unlikely(!imap.br_startblock && 527 !(XFS_IS_REALTIME_INODE(ip)))) { 528 error = xfs_cmn_err_fsblock_zero(ip, &imap); 529 goto error_out; 530 } 531 532 *ret_imap = imap; 533 *nmaps = 1; 534 return 0; 535 536 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */ 537 xfs_bmap_cancel(&free_list); 538 XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag); 539 540 error1: /* Just cancel transaction */ 541 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 542 *nmaps = 0; /* nothing set-up here */ 543 544 error_out: 545 return XFS_ERROR(error); 546 } 547 548 /* 549 * If the caller is doing a write at the end of the file, 550 * then extend the allocation out to the file system's write 551 * iosize. We clean up any extra space left over when the 552 * file is closed in xfs_inactive(). 553 * 554 * For sync writes, we are flushing delayed allocate space to 555 * try to make additional space available for allocation near 556 * the filesystem full boundary - preallocation hurts in that 557 * situation, of course. 558 */ 559 STATIC int 560 xfs_iomap_eof_want_preallocate( 561 xfs_mount_t *mp, 562 xfs_inode_t *ip, 563 xfs_fsize_t isize, 564 xfs_off_t offset, 565 size_t count, 566 int ioflag, 567 xfs_bmbt_irec_t *imap, 568 int nimaps, 569 int *prealloc) 570 { 571 xfs_fileoff_t start_fsb; 572 xfs_filblks_t count_fsb; 573 xfs_fsblock_t firstblock; 574 int n, error, imaps; 575 576 *prealloc = 0; 577 if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize) 578 return 0; 579 580 /* 581 * If there are any real blocks past eof, then don't 582 * do any speculative allocation. 583 */ 584 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1))); 585 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp)); 586 while (count_fsb > 0) { 587 imaps = nimaps; 588 firstblock = NULLFSBLOCK; 589 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0, 590 &firstblock, 0, imap, &imaps, NULL, NULL); 591 if (error) 592 return error; 593 for (n = 0; n < imaps; n++) { 594 if ((imap[n].br_startblock != HOLESTARTBLOCK) && 595 (imap[n].br_startblock != DELAYSTARTBLOCK)) 596 return 0; 597 start_fsb += imap[n].br_blockcount; 598 count_fsb -= imap[n].br_blockcount; 599 } 600 } 601 *prealloc = 1; 602 return 0; 603 } 604 605 int 606 xfs_iomap_write_delay( 607 xfs_inode_t *ip, 608 xfs_off_t offset, 609 size_t count, 610 int ioflag, 611 xfs_bmbt_irec_t *ret_imap, 612 int *nmaps) 613 { 614 xfs_mount_t *mp = ip->i_mount; 615 xfs_fileoff_t offset_fsb; 616 xfs_fileoff_t last_fsb; 617 xfs_off_t aligned_offset; 618 xfs_fileoff_t ioalign; 619 xfs_fsblock_t firstblock; 620 xfs_extlen_t extsz; 621 xfs_fsize_t isize; 622 int nimaps; 623 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS]; 624 int prealloc, fsynced = 0; 625 int error; 626 627 ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0); 628 629 /* 630 * Make sure that the dquots are there. This doesn't hold 631 * the ilock across a disk read. 632 */ 633 error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED); 634 if (error) 635 return XFS_ERROR(error); 636 637 extsz = xfs_get_extsz_hint(ip); 638 offset_fsb = XFS_B_TO_FSBT(mp, offset); 639 640 retry: 641 isize = ip->i_size; 642 if (ip->i_new_size > isize) 643 isize = ip->i_new_size; 644 645 error = xfs_iomap_eof_want_preallocate(mp, ip, isize, offset, count, 646 ioflag, imap, XFS_WRITE_IMAPS, &prealloc); 647 if (error) 648 return error; 649 650 if (prealloc) { 651 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1)); 652 ioalign = XFS_B_TO_FSBT(mp, aligned_offset); 653 last_fsb = ioalign + mp->m_writeio_blocks; 654 } else { 655 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); 656 } 657 658 if (prealloc || extsz) { 659 error = xfs_iomap_eof_align_last_fsb(mp, ip, isize, extsz, 660 &last_fsb); 661 if (error) 662 return error; 663 } 664 665 nimaps = XFS_WRITE_IMAPS; 666 firstblock = NULLFSBLOCK; 667 error = xfs_bmapi(NULL, ip, offset_fsb, 668 (xfs_filblks_t)(last_fsb - offset_fsb), 669 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE | 670 XFS_BMAPI_ENTIRE, &firstblock, 1, imap, 671 &nimaps, NULL, NULL); 672 if (error && (error != ENOSPC)) 673 return XFS_ERROR(error); 674 675 /* 676 * If bmapi returned us nothing, and if we didn't get back EDQUOT, 677 * then we must have run out of space - flush delalloc, and retry.. 678 */ 679 if (nimaps == 0) { 680 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE, 681 ip, offset, count); 682 if (xfs_flush_space(ip, &fsynced, &ioflag)) 683 return XFS_ERROR(ENOSPC); 684 685 error = 0; 686 goto retry; 687 } 688 689 if (unlikely(!imap[0].br_startblock && 690 !(XFS_IS_REALTIME_INODE(ip)))) 691 return xfs_cmn_err_fsblock_zero(ip, &imap[0]); 692 693 *ret_imap = imap[0]; 694 *nmaps = 1; 695 696 return 0; 697 } 698 699 /* 700 * Pass in a delayed allocate extent, convert it to real extents; 701 * return to the caller the extent we create which maps on top of 702 * the originating callers request. 703 * 704 * Called without a lock on the inode. 705 * 706 * We no longer bother to look at the incoming map - all we have to 707 * guarantee is that whatever we allocate fills the required range. 708 */ 709 int 710 xfs_iomap_write_allocate( 711 xfs_inode_t *ip, 712 xfs_off_t offset, 713 size_t count, 714 xfs_bmbt_irec_t *map, 715 int *retmap) 716 { 717 xfs_mount_t *mp = ip->i_mount; 718 xfs_fileoff_t offset_fsb, last_block; 719 xfs_fileoff_t end_fsb, map_start_fsb; 720 xfs_fsblock_t first_block; 721 xfs_bmap_free_t free_list; 722 xfs_filblks_t count_fsb; 723 xfs_bmbt_irec_t imap; 724 xfs_trans_t *tp; 725 int nimaps, committed; 726 int error = 0; 727 int nres; 728 729 *retmap = 0; 730 731 /* 732 * Make sure that the dquots are there. 733 */ 734 if ((error = XFS_QM_DQATTACH(mp, ip, 0))) 735 return XFS_ERROR(error); 736 737 offset_fsb = XFS_B_TO_FSBT(mp, offset); 738 count_fsb = map->br_blockcount; 739 map_start_fsb = map->br_startoff; 740 741 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); 742 743 while (count_fsb != 0) { 744 /* 745 * Set up a transaction with which to allocate the 746 * backing store for the file. Do allocations in a 747 * loop until we get some space in the range we are 748 * interested in. The other space that might be allocated 749 * is in the delayed allocation extent on which we sit 750 * but before our buffer starts. 751 */ 752 753 nimaps = 0; 754 while (nimaps == 0) { 755 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); 756 tp->t_flags |= XFS_TRANS_RESERVE; 757 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); 758 error = xfs_trans_reserve(tp, nres, 759 XFS_WRITE_LOG_RES(mp), 760 0, XFS_TRANS_PERM_LOG_RES, 761 XFS_WRITE_LOG_COUNT); 762 if (error) { 763 xfs_trans_cancel(tp, 0); 764 return XFS_ERROR(error); 765 } 766 xfs_ilock(ip, XFS_ILOCK_EXCL); 767 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 768 xfs_trans_ihold(tp, ip); 769 770 XFS_BMAP_INIT(&free_list, &first_block); 771 772 /* 773 * it is possible that the extents have changed since 774 * we did the read call as we dropped the ilock for a 775 * while. We have to be careful about truncates or hole 776 * punchs here - we are not allowed to allocate 777 * non-delalloc blocks here. 778 * 779 * The only protection against truncation is the pages 780 * for the range we are being asked to convert are 781 * locked and hence a truncate will block on them 782 * first. 783 * 784 * As a result, if we go beyond the range we really 785 * need and hit an delalloc extent boundary followed by 786 * a hole while we have excess blocks in the map, we 787 * will fill the hole incorrectly and overrun the 788 * transaction reservation. 789 * 790 * Using a single map prevents this as we are forced to 791 * check each map we look for overlap with the desired 792 * range and abort as soon as we find it. Also, given 793 * that we only return a single map, having one beyond 794 * what we can return is probably a bit silly. 795 * 796 * We also need to check that we don't go beyond EOF; 797 * this is a truncate optimisation as a truncate sets 798 * the new file size before block on the pages we 799 * currently have locked under writeback. Because they 800 * are about to be tossed, we don't need to write them 801 * back.... 802 */ 803 nimaps = 1; 804 end_fsb = XFS_B_TO_FSB(mp, ip->i_size); 805 xfs_bmap_last_offset(NULL, ip, &last_block, 806 XFS_DATA_FORK); 807 last_block = XFS_FILEOFF_MAX(last_block, end_fsb); 808 if ((map_start_fsb + count_fsb) > last_block) { 809 count_fsb = last_block - map_start_fsb; 810 if (count_fsb == 0) { 811 error = EAGAIN; 812 goto trans_cancel; 813 } 814 } 815 816 /* Go get the actual blocks */ 817 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb, 818 XFS_BMAPI_WRITE, &first_block, 1, 819 &imap, &nimaps, &free_list, NULL); 820 if (error) 821 goto trans_cancel; 822 823 error = xfs_bmap_finish(&tp, &free_list, &committed); 824 if (error) 825 goto trans_cancel; 826 827 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 828 if (error) 829 goto error0; 830 831 xfs_iunlock(ip, XFS_ILOCK_EXCL); 832 } 833 834 /* 835 * See if we were able to allocate an extent that 836 * covers at least part of the callers request 837 */ 838 if (unlikely(!imap.br_startblock && 839 XFS_IS_REALTIME_INODE(ip))) 840 return xfs_cmn_err_fsblock_zero(ip, &imap); 841 if ((offset_fsb >= imap.br_startoff) && 842 (offset_fsb < (imap.br_startoff + 843 imap.br_blockcount))) { 844 *map = imap; 845 *retmap = 1; 846 XFS_STATS_INC(xs_xstrat_quick); 847 return 0; 848 } 849 850 /* 851 * So far we have not mapped the requested part of the 852 * file, just surrounding data, try again. 853 */ 854 count_fsb -= imap.br_blockcount; 855 map_start_fsb = imap.br_startoff + imap.br_blockcount; 856 } 857 858 trans_cancel: 859 xfs_bmap_cancel(&free_list); 860 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); 861 error0: 862 xfs_iunlock(ip, XFS_ILOCK_EXCL); 863 return XFS_ERROR(error); 864 } 865 866 int 867 xfs_iomap_write_unwritten( 868 xfs_inode_t *ip, 869 xfs_off_t offset, 870 size_t count) 871 { 872 xfs_mount_t *mp = ip->i_mount; 873 xfs_fileoff_t offset_fsb; 874 xfs_filblks_t count_fsb; 875 xfs_filblks_t numblks_fsb; 876 xfs_fsblock_t firstfsb; 877 int nimaps; 878 xfs_trans_t *tp; 879 xfs_bmbt_irec_t imap; 880 xfs_bmap_free_t free_list; 881 uint resblks; 882 int committed; 883 int error; 884 885 xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN, ip, offset, count); 886 887 offset_fsb = XFS_B_TO_FSBT(mp, offset); 888 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); 889 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); 890 891 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; 892 893 do { 894 /* 895 * set up a transaction to convert the range of extents 896 * from unwritten to real. Do allocations in a loop until 897 * we have covered the range passed in. 898 */ 899 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); 900 tp->t_flags |= XFS_TRANS_RESERVE; 901 error = xfs_trans_reserve(tp, resblks, 902 XFS_WRITE_LOG_RES(mp), 0, 903 XFS_TRANS_PERM_LOG_RES, 904 XFS_WRITE_LOG_COUNT); 905 if (error) { 906 xfs_trans_cancel(tp, 0); 907 return XFS_ERROR(error); 908 } 909 910 xfs_ilock(ip, XFS_ILOCK_EXCL); 911 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); 912 xfs_trans_ihold(tp, ip); 913 914 /* 915 * Modify the unwritten extent state of the buffer. 916 */ 917 XFS_BMAP_INIT(&free_list, &firstfsb); 918 nimaps = 1; 919 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, 920 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb, 921 1, &imap, &nimaps, &free_list, NULL); 922 if (error) 923 goto error_on_bmapi_transaction; 924 925 error = xfs_bmap_finish(&(tp), &(free_list), &committed); 926 if (error) 927 goto error_on_bmapi_transaction; 928 929 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); 930 xfs_iunlock(ip, XFS_ILOCK_EXCL); 931 if (error) 932 return XFS_ERROR(error); 933 934 if (unlikely(!imap.br_startblock && 935 !(XFS_IS_REALTIME_INODE(ip)))) 936 return xfs_cmn_err_fsblock_zero(ip, &imap); 937 938 if ((numblks_fsb = imap.br_blockcount) == 0) { 939 /* 940 * The numblks_fsb value should always get 941 * smaller, otherwise the loop is stuck. 942 */ 943 ASSERT(imap.br_blockcount); 944 break; 945 } 946 offset_fsb += numblks_fsb; 947 count_fsb -= numblks_fsb; 948 } while (count_fsb > 0); 949 950 return 0; 951 952 error_on_bmapi_transaction: 953 xfs_bmap_cancel(&free_list); 954 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); 955 xfs_iunlock(ip, XFS_ILOCK_EXCL); 956 return XFS_ERROR(error); 957 } 958