| 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_log.h" |
| 21 | #include "xfs_trans.h" |
| 22 | #include "xfs_sb.h" |
| 23 | #include "xfs_ag.h" |
| 24 | #include "xfs_alloc.h" |
| 25 | #include "xfs_quota.h" |
| 26 | #include "xfs_mount.h" |
| 27 | #include "xfs_bmap_btree.h" |
| 28 | #include "xfs_alloc_btree.h" |
| 29 | #include "xfs_ialloc_btree.h" |
| 30 | #include "xfs_dinode.h" |
| 31 | #include "xfs_inode.h" |
| 32 | #include "xfs_inode_item.h" |
| 33 | #include "xfs_btree.h" |
| 34 | #include "xfs_bmap.h" |
| 35 | #include "xfs_rtalloc.h" |
| 36 | #include "xfs_error.h" |
| 37 | #include "xfs_itable.h" |
| 38 | #include "xfs_attr.h" |
| 39 | #include "xfs_buf_item.h" |
| 40 | #include "xfs_trans_space.h" |
| 41 | #include "xfs_utils.h" |
| 42 | #include "xfs_iomap.h" |
| 43 | #include "xfs_trace.h" |
| 44 | |
| 45 | |
| 46 | #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ |
| 47 | << mp->m_writeio_log) |
| 48 | #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP |
| 49 | |
| 50 | STATIC int |
| 51 | xfs_iomap_eof_align_last_fsb( |
| 52 | xfs_mount_t *mp, |
| 53 | xfs_inode_t *ip, |
| 54 | xfs_extlen_t extsize, |
| 55 | xfs_fileoff_t *last_fsb) |
| 56 | { |
| 57 | xfs_fileoff_t new_last_fsb = 0; |
| 58 | xfs_extlen_t align = 0; |
| 59 | int eof, error; |
| 60 | |
| 61 | if (!XFS_IS_REALTIME_INODE(ip)) { |
| 62 | /* |
| 63 | * Round up the allocation request to a stripe unit |
| 64 | * (m_dalign) boundary if the file size is >= stripe unit |
| 65 | * size, and we are allocating past the allocation eof. |
| 66 | * |
| 67 | * If mounted with the "-o swalloc" option the alignment is |
| 68 | * increased from the strip unit size to the stripe width. |
| 69 | */ |
| 70 | if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC)) |
| 71 | align = mp->m_swidth; |
| 72 | else if (mp->m_dalign) |
| 73 | align = mp->m_dalign; |
| 74 | |
| 75 | if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align)) |
| 76 | new_last_fsb = roundup_64(*last_fsb, align); |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * Always round up the allocation request to an extent boundary |
| 81 | * (when file on a real-time subvolume or has di_extsize hint). |
| 82 | */ |
| 83 | if (extsize) { |
| 84 | if (new_last_fsb) |
| 85 | align = roundup_64(new_last_fsb, extsize); |
| 86 | else |
| 87 | align = extsize; |
| 88 | new_last_fsb = roundup_64(*last_fsb, align); |
| 89 | } |
| 90 | |
| 91 | if (new_last_fsb) { |
| 92 | error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); |
| 93 | if (error) |
| 94 | return error; |
| 95 | if (eof) |
| 96 | *last_fsb = new_last_fsb; |
| 97 | } |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | STATIC int |
| 102 | xfs_alert_fsblock_zero( |
| 103 | xfs_inode_t *ip, |
| 104 | xfs_bmbt_irec_t *imap) |
| 105 | { |
| 106 | xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO, |
| 107 | "Access to block zero in inode %llu " |
| 108 | "start_block: %llx start_off: %llx " |
| 109 | "blkcnt: %llx extent-state: %x\n", |
| 110 | (unsigned long long)ip->i_ino, |
| 111 | (unsigned long long)imap->br_startblock, |
| 112 | (unsigned long long)imap->br_startoff, |
| 113 | (unsigned long long)imap->br_blockcount, |
| 114 | imap->br_state); |
| 115 | return EFSCORRUPTED; |
| 116 | } |
| 117 | |
| 118 | int |
| 119 | xfs_iomap_write_direct( |
| 120 | xfs_inode_t *ip, |
| 121 | xfs_off_t offset, |
| 122 | size_t count, |
| 123 | xfs_bmbt_irec_t *imap, |
| 124 | int nmaps) |
| 125 | { |
| 126 | xfs_mount_t *mp = ip->i_mount; |
| 127 | xfs_fileoff_t offset_fsb; |
| 128 | xfs_fileoff_t last_fsb; |
| 129 | xfs_filblks_t count_fsb, resaligned; |
| 130 | xfs_fsblock_t firstfsb; |
| 131 | xfs_extlen_t extsz, temp; |
| 132 | int nimaps; |
| 133 | int bmapi_flag; |
| 134 | int quota_flag; |
| 135 | int rt; |
| 136 | xfs_trans_t *tp; |
| 137 | xfs_bmap_free_t free_list; |
| 138 | uint qblocks, resblks, resrtextents; |
| 139 | int committed; |
| 140 | int error; |
| 141 | |
| 142 | error = xfs_qm_dqattach(ip, 0); |
| 143 | if (error) |
| 144 | return XFS_ERROR(error); |
| 145 | |
| 146 | rt = XFS_IS_REALTIME_INODE(ip); |
| 147 | extsz = xfs_get_extsz_hint(ip); |
| 148 | |
| 149 | offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| 150 | last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); |
| 151 | if ((offset + count) > XFS_ISIZE(ip)) { |
| 152 | error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); |
| 153 | if (error) |
| 154 | return XFS_ERROR(error); |
| 155 | } else { |
| 156 | if (nmaps && (imap->br_startblock == HOLESTARTBLOCK)) |
| 157 | last_fsb = MIN(last_fsb, (xfs_fileoff_t) |
| 158 | imap->br_blockcount + |
| 159 | imap->br_startoff); |
| 160 | } |
| 161 | count_fsb = last_fsb - offset_fsb; |
| 162 | ASSERT(count_fsb > 0); |
| 163 | |
| 164 | resaligned = count_fsb; |
| 165 | if (unlikely(extsz)) { |
| 166 | if ((temp = do_mod(offset_fsb, extsz))) |
| 167 | resaligned += temp; |
| 168 | if ((temp = do_mod(resaligned, extsz))) |
| 169 | resaligned += extsz - temp; |
| 170 | } |
| 171 | |
| 172 | if (unlikely(rt)) { |
| 173 | resrtextents = qblocks = resaligned; |
| 174 | resrtextents /= mp->m_sb.sb_rextsize; |
| 175 | resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); |
| 176 | quota_flag = XFS_QMOPT_RES_RTBLKS; |
| 177 | } else { |
| 178 | resrtextents = 0; |
| 179 | resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); |
| 180 | quota_flag = XFS_QMOPT_RES_REGBLKS; |
| 181 | } |
| 182 | |
| 183 | /* |
| 184 | * Allocate and setup the transaction |
| 185 | */ |
| 186 | tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); |
| 187 | error = xfs_trans_reserve(tp, resblks, |
| 188 | XFS_WRITE_LOG_RES(mp), resrtextents, |
| 189 | XFS_TRANS_PERM_LOG_RES, |
| 190 | XFS_WRITE_LOG_COUNT); |
| 191 | /* |
| 192 | * Check for running out of space, note: need lock to return |
| 193 | */ |
| 194 | if (error) { |
| 195 | xfs_trans_cancel(tp, 0); |
| 196 | return XFS_ERROR(error); |
| 197 | } |
| 198 | |
| 199 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 200 | |
| 201 | error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); |
| 202 | if (error) |
| 203 | goto out_trans_cancel; |
| 204 | |
| 205 | xfs_trans_ijoin(tp, ip, 0); |
| 206 | |
| 207 | bmapi_flag = 0; |
| 208 | if (offset < XFS_ISIZE(ip) || extsz) |
| 209 | bmapi_flag |= XFS_BMAPI_PREALLOC; |
| 210 | |
| 211 | /* |
| 212 | * From this point onwards we overwrite the imap pointer that the |
| 213 | * caller gave to us. |
| 214 | */ |
| 215 | xfs_bmap_init(&free_list, &firstfsb); |
| 216 | nimaps = 1; |
| 217 | error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flag, |
| 218 | &firstfsb, 0, imap, &nimaps, &free_list); |
| 219 | if (error) |
| 220 | goto out_bmap_cancel; |
| 221 | |
| 222 | /* |
| 223 | * Complete the transaction |
| 224 | */ |
| 225 | error = xfs_bmap_finish(&tp, &free_list, &committed); |
| 226 | if (error) |
| 227 | goto out_bmap_cancel; |
| 228 | error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); |
| 229 | if (error) |
| 230 | goto out_unlock; |
| 231 | |
| 232 | /* |
| 233 | * Copy any maps to caller's array and return any error. |
| 234 | */ |
| 235 | if (nimaps == 0) { |
| 236 | error = XFS_ERROR(ENOSPC); |
| 237 | goto out_unlock; |
| 238 | } |
| 239 | |
| 240 | if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| 241 | error = xfs_alert_fsblock_zero(ip, imap); |
| 242 | |
| 243 | out_unlock: |
| 244 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 245 | return error; |
| 246 | |
| 247 | out_bmap_cancel: |
| 248 | xfs_bmap_cancel(&free_list); |
| 249 | xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag); |
| 250 | out_trans_cancel: |
| 251 | xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); |
| 252 | goto out_unlock; |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | * If the caller is doing a write at the end of the file, then extend the |
| 257 | * allocation out to the file system's write iosize. We clean up any extra |
| 258 | * space left over when the file is closed in xfs_inactive(). |
| 259 | * |
| 260 | * If we find we already have delalloc preallocation beyond EOF, don't do more |
| 261 | * preallocation as it it not needed. |
| 262 | */ |
| 263 | STATIC int |
| 264 | xfs_iomap_eof_want_preallocate( |
| 265 | xfs_mount_t *mp, |
| 266 | xfs_inode_t *ip, |
| 267 | xfs_off_t offset, |
| 268 | size_t count, |
| 269 | xfs_bmbt_irec_t *imap, |
| 270 | int nimaps, |
| 271 | int *prealloc) |
| 272 | { |
| 273 | xfs_fileoff_t start_fsb; |
| 274 | xfs_filblks_t count_fsb; |
| 275 | xfs_fsblock_t firstblock; |
| 276 | int n, error, imaps; |
| 277 | int found_delalloc = 0; |
| 278 | |
| 279 | *prealloc = 0; |
| 280 | if (offset + count <= XFS_ISIZE(ip)) |
| 281 | return 0; |
| 282 | |
| 283 | /* |
| 284 | * If there are any real blocks past eof, then don't |
| 285 | * do any speculative allocation. |
| 286 | */ |
| 287 | start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1))); |
| 288 | count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp)); |
| 289 | while (count_fsb > 0) { |
| 290 | imaps = nimaps; |
| 291 | firstblock = NULLFSBLOCK; |
| 292 | error = xfs_bmapi_read(ip, start_fsb, count_fsb, imap, &imaps, |
| 293 | 0); |
| 294 | if (error) |
| 295 | return error; |
| 296 | for (n = 0; n < imaps; n++) { |
| 297 | if ((imap[n].br_startblock != HOLESTARTBLOCK) && |
| 298 | (imap[n].br_startblock != DELAYSTARTBLOCK)) |
| 299 | return 0; |
| 300 | start_fsb += imap[n].br_blockcount; |
| 301 | count_fsb -= imap[n].br_blockcount; |
| 302 | |
| 303 | if (imap[n].br_startblock == DELAYSTARTBLOCK) |
| 304 | found_delalloc = 1; |
| 305 | } |
| 306 | } |
| 307 | if (!found_delalloc) |
| 308 | *prealloc = 1; |
| 309 | return 0; |
| 310 | } |
| 311 | |
| 312 | /* |
| 313 | * If we don't have a user specified preallocation size, dynamically increase |
| 314 | * the preallocation size as the size of the file grows. Cap the maximum size |
| 315 | * at a single extent or less if the filesystem is near full. The closer the |
| 316 | * filesystem is to full, the smaller the maximum prealocation. |
| 317 | */ |
| 318 | STATIC xfs_fsblock_t |
| 319 | xfs_iomap_prealloc_size( |
| 320 | struct xfs_mount *mp, |
| 321 | struct xfs_inode *ip) |
| 322 | { |
| 323 | xfs_fsblock_t alloc_blocks = 0; |
| 324 | |
| 325 | if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) { |
| 326 | int shift = 0; |
| 327 | int64_t freesp; |
| 328 | |
| 329 | /* |
| 330 | * rounddown_pow_of_two() returns an undefined result |
| 331 | * if we pass in alloc_blocks = 0. Hence the "+ 1" to |
| 332 | * ensure we always pass in a non-zero value. |
| 333 | */ |
| 334 | alloc_blocks = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)) + 1; |
| 335 | alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN, |
| 336 | rounddown_pow_of_two(alloc_blocks)); |
| 337 | |
| 338 | xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT); |
| 339 | freesp = mp->m_sb.sb_fdblocks; |
| 340 | if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) { |
| 341 | shift = 2; |
| 342 | if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT]) |
| 343 | shift++; |
| 344 | if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT]) |
| 345 | shift++; |
| 346 | if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT]) |
| 347 | shift++; |
| 348 | if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT]) |
| 349 | shift++; |
| 350 | } |
| 351 | if (shift) |
| 352 | alloc_blocks >>= shift; |
| 353 | } |
| 354 | |
| 355 | if (alloc_blocks < mp->m_writeio_blocks) |
| 356 | alloc_blocks = mp->m_writeio_blocks; |
| 357 | |
| 358 | return alloc_blocks; |
| 359 | } |
| 360 | |
| 361 | int |
| 362 | xfs_iomap_write_delay( |
| 363 | xfs_inode_t *ip, |
| 364 | xfs_off_t offset, |
| 365 | size_t count, |
| 366 | xfs_bmbt_irec_t *ret_imap) |
| 367 | { |
| 368 | xfs_mount_t *mp = ip->i_mount; |
| 369 | xfs_fileoff_t offset_fsb; |
| 370 | xfs_fileoff_t last_fsb; |
| 371 | xfs_off_t aligned_offset; |
| 372 | xfs_fileoff_t ioalign; |
| 373 | xfs_extlen_t extsz; |
| 374 | int nimaps; |
| 375 | xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS]; |
| 376 | int prealloc, flushed = 0; |
| 377 | int error; |
| 378 | |
| 379 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); |
| 380 | |
| 381 | /* |
| 382 | * Make sure that the dquots are there. This doesn't hold |
| 383 | * the ilock across a disk read. |
| 384 | */ |
| 385 | error = xfs_qm_dqattach_locked(ip, 0); |
| 386 | if (error) |
| 387 | return XFS_ERROR(error); |
| 388 | |
| 389 | extsz = xfs_get_extsz_hint(ip); |
| 390 | offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| 391 | |
| 392 | |
| 393 | error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count, |
| 394 | imap, XFS_WRITE_IMAPS, &prealloc); |
| 395 | if (error) |
| 396 | return error; |
| 397 | |
| 398 | retry: |
| 399 | if (prealloc) { |
| 400 | xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip); |
| 401 | |
| 402 | aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1)); |
| 403 | ioalign = XFS_B_TO_FSBT(mp, aligned_offset); |
| 404 | last_fsb = ioalign + alloc_blocks; |
| 405 | } else { |
| 406 | last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); |
| 407 | } |
| 408 | |
| 409 | if (prealloc || extsz) { |
| 410 | error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); |
| 411 | if (error) |
| 412 | return error; |
| 413 | } |
| 414 | |
| 415 | /* |
| 416 | * Make sure preallocation does not create extents beyond the range we |
| 417 | * actually support in this filesystem. |
| 418 | */ |
| 419 | if (last_fsb > XFS_B_TO_FSB(mp, mp->m_maxioffset)) |
| 420 | last_fsb = XFS_B_TO_FSB(mp, mp->m_maxioffset); |
| 421 | |
| 422 | ASSERT(last_fsb > offset_fsb); |
| 423 | |
| 424 | nimaps = XFS_WRITE_IMAPS; |
| 425 | error = xfs_bmapi_delay(ip, offset_fsb, last_fsb - offset_fsb, |
| 426 | imap, &nimaps, XFS_BMAPI_ENTIRE); |
| 427 | switch (error) { |
| 428 | case 0: |
| 429 | case ENOSPC: |
| 430 | case EDQUOT: |
| 431 | break; |
| 432 | default: |
| 433 | return XFS_ERROR(error); |
| 434 | } |
| 435 | |
| 436 | /* |
| 437 | * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. For |
| 438 | * ENOSPC, * flush all other inodes with delalloc blocks to free up |
| 439 | * some of the excess reserved metadata space. For both cases, retry |
| 440 | * without EOF preallocation. |
| 441 | */ |
| 442 | if (nimaps == 0) { |
| 443 | trace_xfs_delalloc_enospc(ip, offset, count); |
| 444 | if (flushed) |
| 445 | return XFS_ERROR(error ? error : ENOSPC); |
| 446 | |
| 447 | if (error == ENOSPC) { |
| 448 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 449 | xfs_flush_inodes(ip); |
| 450 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 451 | } |
| 452 | |
| 453 | flushed = 1; |
| 454 | error = 0; |
| 455 | prealloc = 0; |
| 456 | goto retry; |
| 457 | } |
| 458 | |
| 459 | if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| 460 | return xfs_alert_fsblock_zero(ip, &imap[0]); |
| 461 | |
| 462 | *ret_imap = imap[0]; |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * Pass in a delayed allocate extent, convert it to real extents; |
| 468 | * return to the caller the extent we create which maps on top of |
| 469 | * the originating callers request. |
| 470 | * |
| 471 | * Called without a lock on the inode. |
| 472 | * |
| 473 | * We no longer bother to look at the incoming map - all we have to |
| 474 | * guarantee is that whatever we allocate fills the required range. |
| 475 | */ |
| 476 | int |
| 477 | xfs_iomap_write_allocate( |
| 478 | xfs_inode_t *ip, |
| 479 | xfs_off_t offset, |
| 480 | size_t count, |
| 481 | xfs_bmbt_irec_t *imap) |
| 482 | { |
| 483 | xfs_mount_t *mp = ip->i_mount; |
| 484 | xfs_fileoff_t offset_fsb, last_block; |
| 485 | xfs_fileoff_t end_fsb, map_start_fsb; |
| 486 | xfs_fsblock_t first_block; |
| 487 | xfs_bmap_free_t free_list; |
| 488 | xfs_filblks_t count_fsb; |
| 489 | xfs_trans_t *tp; |
| 490 | int nimaps, committed; |
| 491 | int error = 0; |
| 492 | int nres; |
| 493 | |
| 494 | /* |
| 495 | * Make sure that the dquots are there. |
| 496 | */ |
| 497 | error = xfs_qm_dqattach(ip, 0); |
| 498 | if (error) |
| 499 | return XFS_ERROR(error); |
| 500 | |
| 501 | offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| 502 | count_fsb = imap->br_blockcount; |
| 503 | map_start_fsb = imap->br_startoff; |
| 504 | |
| 505 | XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); |
| 506 | |
| 507 | while (count_fsb != 0) { |
| 508 | /* |
| 509 | * Set up a transaction with which to allocate the |
| 510 | * backing store for the file. Do allocations in a |
| 511 | * loop until we get some space in the range we are |
| 512 | * interested in. The other space that might be allocated |
| 513 | * is in the delayed allocation extent on which we sit |
| 514 | * but before our buffer starts. |
| 515 | */ |
| 516 | |
| 517 | nimaps = 0; |
| 518 | while (nimaps == 0) { |
| 519 | tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); |
| 520 | tp->t_flags |= XFS_TRANS_RESERVE; |
| 521 | nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); |
| 522 | error = xfs_trans_reserve(tp, nres, |
| 523 | XFS_WRITE_LOG_RES(mp), |
| 524 | 0, XFS_TRANS_PERM_LOG_RES, |
| 525 | XFS_WRITE_LOG_COUNT); |
| 526 | if (error) { |
| 527 | xfs_trans_cancel(tp, 0); |
| 528 | return XFS_ERROR(error); |
| 529 | } |
| 530 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 531 | xfs_trans_ijoin(tp, ip, 0); |
| 532 | |
| 533 | xfs_bmap_init(&free_list, &first_block); |
| 534 | |
| 535 | /* |
| 536 | * it is possible that the extents have changed since |
| 537 | * we did the read call as we dropped the ilock for a |
| 538 | * while. We have to be careful about truncates or hole |
| 539 | * punchs here - we are not allowed to allocate |
| 540 | * non-delalloc blocks here. |
| 541 | * |
| 542 | * The only protection against truncation is the pages |
| 543 | * for the range we are being asked to convert are |
| 544 | * locked and hence a truncate will block on them |
| 545 | * first. |
| 546 | * |
| 547 | * As a result, if we go beyond the range we really |
| 548 | * need and hit an delalloc extent boundary followed by |
| 549 | * a hole while we have excess blocks in the map, we |
| 550 | * will fill the hole incorrectly and overrun the |
| 551 | * transaction reservation. |
| 552 | * |
| 553 | * Using a single map prevents this as we are forced to |
| 554 | * check each map we look for overlap with the desired |
| 555 | * range and abort as soon as we find it. Also, given |
| 556 | * that we only return a single map, having one beyond |
| 557 | * what we can return is probably a bit silly. |
| 558 | * |
| 559 | * We also need to check that we don't go beyond EOF; |
| 560 | * this is a truncate optimisation as a truncate sets |
| 561 | * the new file size before block on the pages we |
| 562 | * currently have locked under writeback. Because they |
| 563 | * are about to be tossed, we don't need to write them |
| 564 | * back.... |
| 565 | */ |
| 566 | nimaps = 1; |
| 567 | end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); |
| 568 | error = xfs_bmap_last_offset(NULL, ip, &last_block, |
| 569 | XFS_DATA_FORK); |
| 570 | if (error) |
| 571 | goto trans_cancel; |
| 572 | |
| 573 | last_block = XFS_FILEOFF_MAX(last_block, end_fsb); |
| 574 | if ((map_start_fsb + count_fsb) > last_block) { |
| 575 | count_fsb = last_block - map_start_fsb; |
| 576 | if (count_fsb == 0) { |
| 577 | error = EAGAIN; |
| 578 | goto trans_cancel; |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | /* |
| 583 | * From this point onwards we overwrite the imap |
| 584 | * pointer that the caller gave to us. |
| 585 | */ |
| 586 | error = xfs_bmapi_write(tp, ip, map_start_fsb, |
| 587 | count_fsb, 0, &first_block, 1, |
| 588 | imap, &nimaps, &free_list); |
| 589 | if (error) |
| 590 | goto trans_cancel; |
| 591 | |
| 592 | error = xfs_bmap_finish(&tp, &free_list, &committed); |
| 593 | if (error) |
| 594 | goto trans_cancel; |
| 595 | |
| 596 | error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); |
| 597 | if (error) |
| 598 | goto error0; |
| 599 | |
| 600 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 601 | } |
| 602 | |
| 603 | /* |
| 604 | * See if we were able to allocate an extent that |
| 605 | * covers at least part of the callers request |
| 606 | */ |
| 607 | if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| 608 | return xfs_alert_fsblock_zero(ip, imap); |
| 609 | |
| 610 | if ((offset_fsb >= imap->br_startoff) && |
| 611 | (offset_fsb < (imap->br_startoff + |
| 612 | imap->br_blockcount))) { |
| 613 | XFS_STATS_INC(xs_xstrat_quick); |
| 614 | return 0; |
| 615 | } |
| 616 | |
| 617 | /* |
| 618 | * So far we have not mapped the requested part of the |
| 619 | * file, just surrounding data, try again. |
| 620 | */ |
| 621 | count_fsb -= imap->br_blockcount; |
| 622 | map_start_fsb = imap->br_startoff + imap->br_blockcount; |
| 623 | } |
| 624 | |
| 625 | trans_cancel: |
| 626 | xfs_bmap_cancel(&free_list); |
| 627 | xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); |
| 628 | error0: |
| 629 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 630 | return XFS_ERROR(error); |
| 631 | } |
| 632 | |
| 633 | int |
| 634 | xfs_iomap_write_unwritten( |
| 635 | xfs_inode_t *ip, |
| 636 | xfs_off_t offset, |
| 637 | size_t count) |
| 638 | { |
| 639 | xfs_mount_t *mp = ip->i_mount; |
| 640 | xfs_fileoff_t offset_fsb; |
| 641 | xfs_filblks_t count_fsb; |
| 642 | xfs_filblks_t numblks_fsb; |
| 643 | xfs_fsblock_t firstfsb; |
| 644 | int nimaps; |
| 645 | xfs_trans_t *tp; |
| 646 | xfs_bmbt_irec_t imap; |
| 647 | xfs_bmap_free_t free_list; |
| 648 | xfs_fsize_t i_size; |
| 649 | uint resblks; |
| 650 | int committed; |
| 651 | int error; |
| 652 | |
| 653 | trace_xfs_unwritten_convert(ip, offset, count); |
| 654 | |
| 655 | offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| 656 | count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); |
| 657 | count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); |
| 658 | |
| 659 | /* |
| 660 | * Reserve enough blocks in this transaction for two complete extent |
| 661 | * btree splits. We may be converting the middle part of an unwritten |
| 662 | * extent and in this case we will insert two new extents in the btree |
| 663 | * each of which could cause a full split. |
| 664 | * |
| 665 | * This reservation amount will be used in the first call to |
| 666 | * xfs_bmbt_split() to select an AG with enough space to satisfy the |
| 667 | * rest of the operation. |
| 668 | */ |
| 669 | resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; |
| 670 | |
| 671 | do { |
| 672 | /* |
| 673 | * set up a transaction to convert the range of extents |
| 674 | * from unwritten to real. Do allocations in a loop until |
| 675 | * we have covered the range passed in. |
| 676 | * |
| 677 | * Note that we open code the transaction allocation here |
| 678 | * to pass KM_NOFS--we can't risk to recursing back into |
| 679 | * the filesystem here as we might be asked to write out |
| 680 | * the same inode that we complete here and might deadlock |
| 681 | * on the iolock. |
| 682 | */ |
| 683 | xfs_wait_for_freeze(mp, SB_FREEZE_TRANS); |
| 684 | tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS); |
| 685 | tp->t_flags |= XFS_TRANS_RESERVE; |
| 686 | error = xfs_trans_reserve(tp, resblks, |
| 687 | XFS_WRITE_LOG_RES(mp), 0, |
| 688 | XFS_TRANS_PERM_LOG_RES, |
| 689 | XFS_WRITE_LOG_COUNT); |
| 690 | if (error) { |
| 691 | xfs_trans_cancel(tp, 0); |
| 692 | return XFS_ERROR(error); |
| 693 | } |
| 694 | |
| 695 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 696 | xfs_trans_ijoin(tp, ip, 0); |
| 697 | |
| 698 | /* |
| 699 | * Modify the unwritten extent state of the buffer. |
| 700 | */ |
| 701 | xfs_bmap_init(&free_list, &firstfsb); |
| 702 | nimaps = 1; |
| 703 | error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, |
| 704 | XFS_BMAPI_CONVERT, &firstfsb, |
| 705 | 1, &imap, &nimaps, &free_list); |
| 706 | if (error) |
| 707 | goto error_on_bmapi_transaction; |
| 708 | |
| 709 | /* |
| 710 | * Log the updated inode size as we go. We have to be careful |
| 711 | * to only log it up to the actual write offset if it is |
| 712 | * halfway into a block. |
| 713 | */ |
| 714 | i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb); |
| 715 | if (i_size > offset + count) |
| 716 | i_size = offset + count; |
| 717 | |
| 718 | i_size = xfs_new_eof(ip, i_size); |
| 719 | if (i_size) { |
| 720 | ip->i_d.di_size = i_size; |
| 721 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); |
| 722 | } |
| 723 | |
| 724 | error = xfs_bmap_finish(&tp, &free_list, &committed); |
| 725 | if (error) |
| 726 | goto error_on_bmapi_transaction; |
| 727 | |
| 728 | error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); |
| 729 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 730 | if (error) |
| 731 | return XFS_ERROR(error); |
| 732 | |
| 733 | if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| 734 | return xfs_alert_fsblock_zero(ip, &imap); |
| 735 | |
| 736 | if ((numblks_fsb = imap.br_blockcount) == 0) { |
| 737 | /* |
| 738 | * The numblks_fsb value should always get |
| 739 | * smaller, otherwise the loop is stuck. |
| 740 | */ |
| 741 | ASSERT(imap.br_blockcount); |
| 742 | break; |
| 743 | } |
| 744 | offset_fsb += numblks_fsb; |
| 745 | count_fsb -= numblks_fsb; |
| 746 | } while (count_fsb > 0); |
| 747 | |
| 748 | return 0; |
| 749 | |
| 750 | error_on_bmapi_transaction: |
| 751 | xfs_bmap_cancel(&free_list); |
| 752 | xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); |
| 753 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 754 | return XFS_ERROR(error); |
| 755 | } |