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