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