1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2006 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include "xfs_fs.h" 8 #include "xfs_shared.h" 9 #include "xfs_format.h" 10 #include "xfs_log_format.h" 11 #include "xfs_trans_resv.h" 12 #include "xfs_mount.h" 13 #include "xfs_inode.h" 14 #include "xfs_errortag.h" 15 #include "xfs_error.h" 16 #include "xfs_icache.h" 17 #include "xfs_trans.h" 18 #include "xfs_ialloc.h" 19 #include "xfs_dir2.h" 20 21 #include <linux/iversion.h> 22 23 /* 24 * If we are doing readahead on an inode buffer, we might be in log recovery 25 * reading an inode allocation buffer that hasn't yet been replayed, and hence 26 * has not had the inode cores stamped into it. Hence for readahead, the buffer 27 * may be potentially invalid. 28 * 29 * If the readahead buffer is invalid, we need to mark it with an error and 30 * clear the DONE status of the buffer so that a followup read will re-read it 31 * from disk. We don't report the error otherwise to avoid warnings during log 32 * recovery and we don't get unnecessary panics on debug kernels. We use EIO here 33 * because all we want to do is say readahead failed; there is no-one to report 34 * the error to, so this will distinguish it from a non-ra verifier failure. 35 * Changes to this readahead error behaviour also need to be reflected in 36 * xfs_dquot_buf_readahead_verify(). 37 */ 38 static void 39 xfs_inode_buf_verify( 40 struct xfs_buf *bp, 41 bool readahead) 42 { 43 struct xfs_mount *mp = bp->b_mount; 44 xfs_agnumber_t agno; 45 int i; 46 int ni; 47 48 /* 49 * Validate the magic number and version of every inode in the buffer 50 */ 51 agno = xfs_daddr_to_agno(mp, XFS_BUF_ADDR(bp)); 52 ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock; 53 for (i = 0; i < ni; i++) { 54 int di_ok; 55 xfs_dinode_t *dip; 56 xfs_agino_t unlinked_ino; 57 58 dip = xfs_buf_offset(bp, (i << mp->m_sb.sb_inodelog)); 59 unlinked_ino = be32_to_cpu(dip->di_next_unlinked); 60 di_ok = xfs_verify_magic16(bp, dip->di_magic) && 61 xfs_dinode_good_version(&mp->m_sb, dip->di_version) && 62 xfs_verify_agino_or_null(mp, agno, unlinked_ino); 63 if (unlikely(XFS_TEST_ERROR(!di_ok, mp, 64 XFS_ERRTAG_ITOBP_INOTOBP))) { 65 if (readahead) { 66 bp->b_flags &= ~XBF_DONE; 67 xfs_buf_ioerror(bp, -EIO); 68 return; 69 } 70 71 #ifdef DEBUG 72 xfs_alert(mp, 73 "bad inode magic/vsn daddr %lld #%d (magic=%x)", 74 (unsigned long long)bp->b_bn, i, 75 be16_to_cpu(dip->di_magic)); 76 #endif 77 xfs_buf_verifier_error(bp, -EFSCORRUPTED, 78 __func__, dip, sizeof(*dip), 79 NULL); 80 return; 81 } 82 } 83 } 84 85 86 static void 87 xfs_inode_buf_read_verify( 88 struct xfs_buf *bp) 89 { 90 xfs_inode_buf_verify(bp, false); 91 } 92 93 static void 94 xfs_inode_buf_readahead_verify( 95 struct xfs_buf *bp) 96 { 97 xfs_inode_buf_verify(bp, true); 98 } 99 100 static void 101 xfs_inode_buf_write_verify( 102 struct xfs_buf *bp) 103 { 104 xfs_inode_buf_verify(bp, false); 105 } 106 107 const struct xfs_buf_ops xfs_inode_buf_ops = { 108 .name = "xfs_inode", 109 .magic16 = { cpu_to_be16(XFS_DINODE_MAGIC), 110 cpu_to_be16(XFS_DINODE_MAGIC) }, 111 .verify_read = xfs_inode_buf_read_verify, 112 .verify_write = xfs_inode_buf_write_verify, 113 }; 114 115 const struct xfs_buf_ops xfs_inode_buf_ra_ops = { 116 .name = "xfs_inode_ra", 117 .magic16 = { cpu_to_be16(XFS_DINODE_MAGIC), 118 cpu_to_be16(XFS_DINODE_MAGIC) }, 119 .verify_read = xfs_inode_buf_readahead_verify, 120 .verify_write = xfs_inode_buf_write_verify, 121 }; 122 123 124 /* 125 * This routine is called to map an inode to the buffer containing the on-disk 126 * version of the inode. It returns a pointer to the buffer containing the 127 * on-disk inode in the bpp parameter, and in the dipp parameter it returns a 128 * pointer to the on-disk inode within that buffer. 129 * 130 * If a non-zero error is returned, then the contents of bpp and dipp are 131 * undefined. 132 */ 133 int 134 xfs_imap_to_bp( 135 struct xfs_mount *mp, 136 struct xfs_trans *tp, 137 struct xfs_imap *imap, 138 struct xfs_dinode **dipp, 139 struct xfs_buf **bpp, 140 uint buf_flags) 141 { 142 struct xfs_buf *bp; 143 int error; 144 145 buf_flags |= XBF_UNMAPPED; 146 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno, 147 (int)imap->im_len, buf_flags, &bp, 148 &xfs_inode_buf_ops); 149 if (error) { 150 ASSERT(error != -EAGAIN || (buf_flags & XBF_TRYLOCK)); 151 return error; 152 } 153 154 *bpp = bp; 155 if (dipp) 156 *dipp = xfs_buf_offset(bp, imap->im_boffset); 157 return 0; 158 } 159 160 static inline struct timespec64 xfs_inode_decode_bigtime(uint64_t ts) 161 { 162 struct timespec64 tv; 163 uint32_t n; 164 165 tv.tv_sec = xfs_bigtime_to_unix(div_u64_rem(ts, NSEC_PER_SEC, &n)); 166 tv.tv_nsec = n; 167 168 return tv; 169 } 170 171 /* Convert an ondisk timestamp to an incore timestamp. */ 172 struct timespec64 173 xfs_inode_from_disk_ts( 174 struct xfs_dinode *dip, 175 const xfs_timestamp_t ts) 176 { 177 struct timespec64 tv; 178 struct xfs_legacy_timestamp *lts; 179 180 if (xfs_dinode_has_bigtime(dip)) 181 return xfs_inode_decode_bigtime(be64_to_cpu(ts)); 182 183 lts = (struct xfs_legacy_timestamp *)&ts; 184 tv.tv_sec = (int)be32_to_cpu(lts->t_sec); 185 tv.tv_nsec = (int)be32_to_cpu(lts->t_nsec); 186 187 return tv; 188 } 189 190 int 191 xfs_inode_from_disk( 192 struct xfs_inode *ip, 193 struct xfs_dinode *from) 194 { 195 struct xfs_icdinode *to = &ip->i_d; 196 struct inode *inode = VFS_I(ip); 197 int error; 198 xfs_failaddr_t fa; 199 200 ASSERT(ip->i_cowfp == NULL); 201 ASSERT(ip->i_afp == NULL); 202 203 fa = xfs_dinode_verify(ip->i_mount, ip->i_ino, from); 204 if (fa) { 205 xfs_inode_verifier_error(ip, -EFSCORRUPTED, "dinode", from, 206 sizeof(*from), fa); 207 return -EFSCORRUPTED; 208 } 209 210 /* 211 * First get the permanent information that is needed to allocate an 212 * inode. If the inode is unused, mode is zero and we shouldn't mess 213 * with the uninitialized part of it. 214 */ 215 to->di_flushiter = be16_to_cpu(from->di_flushiter); 216 inode->i_generation = be32_to_cpu(from->di_gen); 217 inode->i_mode = be16_to_cpu(from->di_mode); 218 if (!inode->i_mode) 219 return 0; 220 221 /* 222 * Convert v1 inodes immediately to v2 inode format as this is the 223 * minimum inode version format we support in the rest of the code. 224 * They will also be unconditionally written back to disk as v2 inodes. 225 */ 226 if (unlikely(from->di_version == 1)) { 227 set_nlink(inode, be16_to_cpu(from->di_onlink)); 228 to->di_projid = 0; 229 } else { 230 set_nlink(inode, be32_to_cpu(from->di_nlink)); 231 to->di_projid = (prid_t)be16_to_cpu(from->di_projid_hi) << 16 | 232 be16_to_cpu(from->di_projid_lo); 233 } 234 235 i_uid_write(inode, be32_to_cpu(from->di_uid)); 236 i_gid_write(inode, be32_to_cpu(from->di_gid)); 237 238 /* 239 * Time is signed, so need to convert to signed 32 bit before 240 * storing in inode timestamp which may be 64 bit. Otherwise 241 * a time before epoch is converted to a time long after epoch 242 * on 64 bit systems. 243 */ 244 inode->i_atime = xfs_inode_from_disk_ts(from, from->di_atime); 245 inode->i_mtime = xfs_inode_from_disk_ts(from, from->di_mtime); 246 inode->i_ctime = xfs_inode_from_disk_ts(from, from->di_ctime); 247 248 to->di_size = be64_to_cpu(from->di_size); 249 to->di_nblocks = be64_to_cpu(from->di_nblocks); 250 to->di_extsize = be32_to_cpu(from->di_extsize); 251 to->di_forkoff = from->di_forkoff; 252 to->di_dmevmask = be32_to_cpu(from->di_dmevmask); 253 to->di_dmstate = be16_to_cpu(from->di_dmstate); 254 to->di_flags = be16_to_cpu(from->di_flags); 255 256 if (xfs_sb_version_has_v3inode(&ip->i_mount->m_sb)) { 257 inode_set_iversion_queried(inode, 258 be64_to_cpu(from->di_changecount)); 259 to->di_crtime = xfs_inode_from_disk_ts(from, from->di_crtime); 260 to->di_flags2 = be64_to_cpu(from->di_flags2); 261 to->di_cowextsize = be32_to_cpu(from->di_cowextsize); 262 } 263 264 error = xfs_iformat_data_fork(ip, from); 265 if (error) 266 return error; 267 if (from->di_forkoff) { 268 error = xfs_iformat_attr_fork(ip, from); 269 if (error) 270 goto out_destroy_data_fork; 271 } 272 if (xfs_is_reflink_inode(ip)) 273 xfs_ifork_init_cow(ip); 274 return 0; 275 276 out_destroy_data_fork: 277 xfs_idestroy_fork(&ip->i_df); 278 return error; 279 } 280 281 /* Convert an incore timestamp to an ondisk timestamp. */ 282 static inline xfs_timestamp_t 283 xfs_inode_to_disk_ts( 284 struct xfs_inode *ip, 285 const struct timespec64 tv) 286 { 287 struct xfs_legacy_timestamp *lts; 288 xfs_timestamp_t ts; 289 290 if (xfs_inode_has_bigtime(ip)) 291 return cpu_to_be64(xfs_inode_encode_bigtime(tv)); 292 293 lts = (struct xfs_legacy_timestamp *)&ts; 294 lts->t_sec = cpu_to_be32(tv.tv_sec); 295 lts->t_nsec = cpu_to_be32(tv.tv_nsec); 296 297 return ts; 298 } 299 300 void 301 xfs_inode_to_disk( 302 struct xfs_inode *ip, 303 struct xfs_dinode *to, 304 xfs_lsn_t lsn) 305 { 306 struct xfs_icdinode *from = &ip->i_d; 307 struct inode *inode = VFS_I(ip); 308 309 to->di_magic = cpu_to_be16(XFS_DINODE_MAGIC); 310 to->di_onlink = 0; 311 312 to->di_format = xfs_ifork_format(&ip->i_df); 313 to->di_uid = cpu_to_be32(i_uid_read(inode)); 314 to->di_gid = cpu_to_be32(i_gid_read(inode)); 315 to->di_projid_lo = cpu_to_be16(from->di_projid & 0xffff); 316 to->di_projid_hi = cpu_to_be16(from->di_projid >> 16); 317 318 memset(to->di_pad, 0, sizeof(to->di_pad)); 319 to->di_atime = xfs_inode_to_disk_ts(ip, inode->i_atime); 320 to->di_mtime = xfs_inode_to_disk_ts(ip, inode->i_mtime); 321 to->di_ctime = xfs_inode_to_disk_ts(ip, inode->i_ctime); 322 to->di_nlink = cpu_to_be32(inode->i_nlink); 323 to->di_gen = cpu_to_be32(inode->i_generation); 324 to->di_mode = cpu_to_be16(inode->i_mode); 325 326 to->di_size = cpu_to_be64(from->di_size); 327 to->di_nblocks = cpu_to_be64(from->di_nblocks); 328 to->di_extsize = cpu_to_be32(from->di_extsize); 329 to->di_nextents = cpu_to_be32(xfs_ifork_nextents(&ip->i_df)); 330 to->di_anextents = cpu_to_be16(xfs_ifork_nextents(ip->i_afp)); 331 to->di_forkoff = from->di_forkoff; 332 to->di_aformat = xfs_ifork_format(ip->i_afp); 333 to->di_dmevmask = cpu_to_be32(from->di_dmevmask); 334 to->di_dmstate = cpu_to_be16(from->di_dmstate); 335 to->di_flags = cpu_to_be16(from->di_flags); 336 337 if (xfs_sb_version_has_v3inode(&ip->i_mount->m_sb)) { 338 to->di_version = 3; 339 to->di_changecount = cpu_to_be64(inode_peek_iversion(inode)); 340 to->di_crtime = xfs_inode_to_disk_ts(ip, from->di_crtime); 341 to->di_flags2 = cpu_to_be64(from->di_flags2); 342 to->di_cowextsize = cpu_to_be32(from->di_cowextsize); 343 to->di_ino = cpu_to_be64(ip->i_ino); 344 to->di_lsn = cpu_to_be64(lsn); 345 memset(to->di_pad2, 0, sizeof(to->di_pad2)); 346 uuid_copy(&to->di_uuid, &ip->i_mount->m_sb.sb_meta_uuid); 347 to->di_flushiter = 0; 348 } else { 349 to->di_version = 2; 350 to->di_flushiter = cpu_to_be16(from->di_flushiter); 351 } 352 } 353 354 static xfs_failaddr_t 355 xfs_dinode_verify_fork( 356 struct xfs_dinode *dip, 357 struct xfs_mount *mp, 358 int whichfork) 359 { 360 uint32_t di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork); 361 362 switch (XFS_DFORK_FORMAT(dip, whichfork)) { 363 case XFS_DINODE_FMT_LOCAL: 364 /* 365 * no local regular files yet 366 */ 367 if (whichfork == XFS_DATA_FORK) { 368 if (S_ISREG(be16_to_cpu(dip->di_mode))) 369 return __this_address; 370 if (be64_to_cpu(dip->di_size) > 371 XFS_DFORK_SIZE(dip, mp, whichfork)) 372 return __this_address; 373 } 374 if (di_nextents) 375 return __this_address; 376 break; 377 case XFS_DINODE_FMT_EXTENTS: 378 if (di_nextents > XFS_DFORK_MAXEXT(dip, mp, whichfork)) 379 return __this_address; 380 break; 381 case XFS_DINODE_FMT_BTREE: 382 if (whichfork == XFS_ATTR_FORK) { 383 if (di_nextents > MAXAEXTNUM) 384 return __this_address; 385 } else if (di_nextents > MAXEXTNUM) { 386 return __this_address; 387 } 388 break; 389 default: 390 return __this_address; 391 } 392 return NULL; 393 } 394 395 static xfs_failaddr_t 396 xfs_dinode_verify_forkoff( 397 struct xfs_dinode *dip, 398 struct xfs_mount *mp) 399 { 400 if (!dip->di_forkoff) 401 return NULL; 402 403 switch (dip->di_format) { 404 case XFS_DINODE_FMT_DEV: 405 if (dip->di_forkoff != (roundup(sizeof(xfs_dev_t), 8) >> 3)) 406 return __this_address; 407 break; 408 case XFS_DINODE_FMT_LOCAL: /* fall through ... */ 409 case XFS_DINODE_FMT_EXTENTS: /* fall through ... */ 410 case XFS_DINODE_FMT_BTREE: 411 if (dip->di_forkoff >= (XFS_LITINO(mp) >> 3)) 412 return __this_address; 413 break; 414 default: 415 return __this_address; 416 } 417 return NULL; 418 } 419 420 xfs_failaddr_t 421 xfs_dinode_verify( 422 struct xfs_mount *mp, 423 xfs_ino_t ino, 424 struct xfs_dinode *dip) 425 { 426 xfs_failaddr_t fa; 427 uint16_t mode; 428 uint16_t flags; 429 uint64_t flags2; 430 uint64_t di_size; 431 432 if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC)) 433 return __this_address; 434 435 /* Verify v3 integrity information first */ 436 if (dip->di_version >= 3) { 437 if (!xfs_sb_version_has_v3inode(&mp->m_sb)) 438 return __this_address; 439 if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize, 440 XFS_DINODE_CRC_OFF)) 441 return __this_address; 442 if (be64_to_cpu(dip->di_ino) != ino) 443 return __this_address; 444 if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_meta_uuid)) 445 return __this_address; 446 } 447 448 /* don't allow invalid i_size */ 449 di_size = be64_to_cpu(dip->di_size); 450 if (di_size & (1ULL << 63)) 451 return __this_address; 452 453 mode = be16_to_cpu(dip->di_mode); 454 if (mode && xfs_mode_to_ftype(mode) == XFS_DIR3_FT_UNKNOWN) 455 return __this_address; 456 457 /* No zero-length symlinks/dirs. */ 458 if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0) 459 return __this_address; 460 461 /* Fork checks carried over from xfs_iformat_fork */ 462 if (mode && 463 be32_to_cpu(dip->di_nextents) + be16_to_cpu(dip->di_anextents) > 464 be64_to_cpu(dip->di_nblocks)) 465 return __this_address; 466 467 if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize) 468 return __this_address; 469 470 flags = be16_to_cpu(dip->di_flags); 471 472 if (mode && (flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp) 473 return __this_address; 474 475 /* check for illegal values of forkoff */ 476 fa = xfs_dinode_verify_forkoff(dip, mp); 477 if (fa) 478 return fa; 479 480 /* Do we have appropriate data fork formats for the mode? */ 481 switch (mode & S_IFMT) { 482 case S_IFIFO: 483 case S_IFCHR: 484 case S_IFBLK: 485 case S_IFSOCK: 486 if (dip->di_format != XFS_DINODE_FMT_DEV) 487 return __this_address; 488 break; 489 case S_IFREG: 490 case S_IFLNK: 491 case S_IFDIR: 492 fa = xfs_dinode_verify_fork(dip, mp, XFS_DATA_FORK); 493 if (fa) 494 return fa; 495 break; 496 case 0: 497 /* Uninitialized inode ok. */ 498 break; 499 default: 500 return __this_address; 501 } 502 503 if (dip->di_forkoff) { 504 fa = xfs_dinode_verify_fork(dip, mp, XFS_ATTR_FORK); 505 if (fa) 506 return fa; 507 } else { 508 /* 509 * If there is no fork offset, this may be a freshly-made inode 510 * in a new disk cluster, in which case di_aformat is zeroed. 511 * Otherwise, such an inode must be in EXTENTS format; this goes 512 * for freed inodes as well. 513 */ 514 switch (dip->di_aformat) { 515 case 0: 516 case XFS_DINODE_FMT_EXTENTS: 517 break; 518 default: 519 return __this_address; 520 } 521 if (dip->di_anextents) 522 return __this_address; 523 } 524 525 /* extent size hint validation */ 526 fa = xfs_inode_validate_extsize(mp, be32_to_cpu(dip->di_extsize), 527 mode, flags); 528 if (fa) 529 return fa; 530 531 /* only version 3 or greater inodes are extensively verified here */ 532 if (dip->di_version < 3) 533 return NULL; 534 535 flags2 = be64_to_cpu(dip->di_flags2); 536 537 /* don't allow reflink/cowextsize if we don't have reflink */ 538 if ((flags2 & (XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)) && 539 !xfs_sb_version_hasreflink(&mp->m_sb)) 540 return __this_address; 541 542 /* only regular files get reflink */ 543 if ((flags2 & XFS_DIFLAG2_REFLINK) && (mode & S_IFMT) != S_IFREG) 544 return __this_address; 545 546 /* don't let reflink and realtime mix */ 547 if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME)) 548 return __this_address; 549 550 /* COW extent size hint validation */ 551 fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize), 552 mode, flags, flags2); 553 if (fa) 554 return fa; 555 556 /* bigtime iflag can only happen on bigtime filesystems */ 557 if (xfs_dinode_has_bigtime(dip) && 558 !xfs_sb_version_hasbigtime(&mp->m_sb)) 559 return __this_address; 560 561 return NULL; 562 } 563 564 void 565 xfs_dinode_calc_crc( 566 struct xfs_mount *mp, 567 struct xfs_dinode *dip) 568 { 569 uint32_t crc; 570 571 if (dip->di_version < 3) 572 return; 573 574 ASSERT(xfs_sb_version_hascrc(&mp->m_sb)); 575 crc = xfs_start_cksum_update((char *)dip, mp->m_sb.sb_inodesize, 576 XFS_DINODE_CRC_OFF); 577 dip->di_crc = xfs_end_cksum(crc); 578 } 579 580 /* 581 * Validate di_extsize hint. 582 * 583 * The rules are documented at xfs_ioctl_setattr_check_extsize(). 584 * These functions must be kept in sync with each other. 585 */ 586 xfs_failaddr_t 587 xfs_inode_validate_extsize( 588 struct xfs_mount *mp, 589 uint32_t extsize, 590 uint16_t mode, 591 uint16_t flags) 592 { 593 bool rt_flag; 594 bool hint_flag; 595 bool inherit_flag; 596 uint32_t extsize_bytes; 597 uint32_t blocksize_bytes; 598 599 rt_flag = (flags & XFS_DIFLAG_REALTIME); 600 hint_flag = (flags & XFS_DIFLAG_EXTSIZE); 601 inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT); 602 extsize_bytes = XFS_FSB_TO_B(mp, extsize); 603 604 if (rt_flag) 605 blocksize_bytes = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog; 606 else 607 blocksize_bytes = mp->m_sb.sb_blocksize; 608 609 if ((hint_flag || inherit_flag) && !(S_ISDIR(mode) || S_ISREG(mode))) 610 return __this_address; 611 612 if (hint_flag && !S_ISREG(mode)) 613 return __this_address; 614 615 if (inherit_flag && !S_ISDIR(mode)) 616 return __this_address; 617 618 if ((hint_flag || inherit_flag) && extsize == 0) 619 return __this_address; 620 621 /* free inodes get flags set to zero but extsize remains */ 622 if (mode && !(hint_flag || inherit_flag) && extsize != 0) 623 return __this_address; 624 625 if (extsize_bytes % blocksize_bytes) 626 return __this_address; 627 628 if (extsize > MAXEXTLEN) 629 return __this_address; 630 631 if (!rt_flag && extsize > mp->m_sb.sb_agblocks / 2) 632 return __this_address; 633 634 return NULL; 635 } 636 637 /* 638 * Validate di_cowextsize hint. 639 * 640 * The rules are documented at xfs_ioctl_setattr_check_cowextsize(). 641 * These functions must be kept in sync with each other. 642 */ 643 xfs_failaddr_t 644 xfs_inode_validate_cowextsize( 645 struct xfs_mount *mp, 646 uint32_t cowextsize, 647 uint16_t mode, 648 uint16_t flags, 649 uint64_t flags2) 650 { 651 bool rt_flag; 652 bool hint_flag; 653 uint32_t cowextsize_bytes; 654 655 rt_flag = (flags & XFS_DIFLAG_REALTIME); 656 hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE); 657 cowextsize_bytes = XFS_FSB_TO_B(mp, cowextsize); 658 659 if (hint_flag && !xfs_sb_version_hasreflink(&mp->m_sb)) 660 return __this_address; 661 662 if (hint_flag && !(S_ISDIR(mode) || S_ISREG(mode))) 663 return __this_address; 664 665 if (hint_flag && cowextsize == 0) 666 return __this_address; 667 668 /* free inodes get flags set to zero but cowextsize remains */ 669 if (mode && !hint_flag && cowextsize != 0) 670 return __this_address; 671 672 if (hint_flag && rt_flag) 673 return __this_address; 674 675 if (cowextsize_bytes % mp->m_sb.sb_blocksize) 676 return __this_address; 677 678 if (cowextsize > MAXEXTLEN) 679 return __this_address; 680 681 if (cowextsize > mp->m_sb.sb_agblocks / 2) 682 return __this_address; 683 684 return NULL; 685 } 686