1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2006 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include <linux/iversion.h> 7 #include "xfs.h" 8 #include "xfs_fs.h" 9 #include "xfs_shared.h" 10 #include "xfs_format.h" 11 #include "xfs_log_format.h" 12 #include "xfs_trans_resv.h" 13 #include "xfs_sb.h" 14 #include "xfs_mount.h" 15 #include "xfs_inode.h" 16 #include "xfs_inode_util.h" 17 #include "xfs_trans.h" 18 #include "xfs_ialloc.h" 19 #include "xfs_health.h" 20 #include "xfs_bmap.h" 21 #include "xfs_error.h" 22 #include "xfs_trace.h" 23 #include "xfs_ag.h" 24 #include "xfs_iunlink_item.h" 25 #include "xfs_inode_item.h" 26 27 uint16_t 28 xfs_flags2diflags( 29 struct xfs_inode *ip, 30 unsigned int xflags) 31 { 32 /* can't set PREALLOC this way, just preserve it */ 33 uint16_t di_flags = 34 (ip->i_diflags & XFS_DIFLAG_PREALLOC); 35 36 if (xflags & FS_XFLAG_IMMUTABLE) 37 di_flags |= XFS_DIFLAG_IMMUTABLE; 38 if (xflags & FS_XFLAG_APPEND) 39 di_flags |= XFS_DIFLAG_APPEND; 40 if (xflags & FS_XFLAG_SYNC) 41 di_flags |= XFS_DIFLAG_SYNC; 42 if (xflags & FS_XFLAG_NOATIME) 43 di_flags |= XFS_DIFLAG_NOATIME; 44 if (xflags & FS_XFLAG_NODUMP) 45 di_flags |= XFS_DIFLAG_NODUMP; 46 if (xflags & FS_XFLAG_NODEFRAG) 47 di_flags |= XFS_DIFLAG_NODEFRAG; 48 if (xflags & FS_XFLAG_FILESTREAM) 49 di_flags |= XFS_DIFLAG_FILESTREAM; 50 if (S_ISDIR(VFS_I(ip)->i_mode)) { 51 if (xflags & FS_XFLAG_RTINHERIT) 52 di_flags |= XFS_DIFLAG_RTINHERIT; 53 if (xflags & FS_XFLAG_NOSYMLINKS) 54 di_flags |= XFS_DIFLAG_NOSYMLINKS; 55 if (xflags & FS_XFLAG_EXTSZINHERIT) 56 di_flags |= XFS_DIFLAG_EXTSZINHERIT; 57 if (xflags & FS_XFLAG_PROJINHERIT) 58 di_flags |= XFS_DIFLAG_PROJINHERIT; 59 } else if (S_ISREG(VFS_I(ip)->i_mode)) { 60 if (xflags & FS_XFLAG_REALTIME) 61 di_flags |= XFS_DIFLAG_REALTIME; 62 if (xflags & FS_XFLAG_EXTSIZE) 63 di_flags |= XFS_DIFLAG_EXTSIZE; 64 } 65 66 return di_flags; 67 } 68 69 uint64_t 70 xfs_flags2diflags2( 71 struct xfs_inode *ip, 72 unsigned int xflags) 73 { 74 uint64_t di_flags2 = 75 (ip->i_diflags2 & (XFS_DIFLAG2_REFLINK | 76 XFS_DIFLAG2_BIGTIME | 77 XFS_DIFLAG2_NREXT64)); 78 79 if (xflags & FS_XFLAG_DAX) 80 di_flags2 |= XFS_DIFLAG2_DAX; 81 if (xflags & FS_XFLAG_COWEXTSIZE) 82 di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; 83 84 return di_flags2; 85 } 86 87 uint32_t 88 xfs_ip2xflags( 89 struct xfs_inode *ip) 90 { 91 uint32_t flags = 0; 92 93 if (ip->i_diflags & XFS_DIFLAG_ANY) { 94 if (ip->i_diflags & XFS_DIFLAG_REALTIME) 95 flags |= FS_XFLAG_REALTIME; 96 if (ip->i_diflags & XFS_DIFLAG_PREALLOC) 97 flags |= FS_XFLAG_PREALLOC; 98 if (ip->i_diflags & XFS_DIFLAG_IMMUTABLE) 99 flags |= FS_XFLAG_IMMUTABLE; 100 if (ip->i_diflags & XFS_DIFLAG_APPEND) 101 flags |= FS_XFLAG_APPEND; 102 if (ip->i_diflags & XFS_DIFLAG_SYNC) 103 flags |= FS_XFLAG_SYNC; 104 if (ip->i_diflags & XFS_DIFLAG_NOATIME) 105 flags |= FS_XFLAG_NOATIME; 106 if (ip->i_diflags & XFS_DIFLAG_NODUMP) 107 flags |= FS_XFLAG_NODUMP; 108 if (ip->i_diflags & XFS_DIFLAG_RTINHERIT) 109 flags |= FS_XFLAG_RTINHERIT; 110 if (ip->i_diflags & XFS_DIFLAG_PROJINHERIT) 111 flags |= FS_XFLAG_PROJINHERIT; 112 if (ip->i_diflags & XFS_DIFLAG_NOSYMLINKS) 113 flags |= FS_XFLAG_NOSYMLINKS; 114 if (ip->i_diflags & XFS_DIFLAG_EXTSIZE) 115 flags |= FS_XFLAG_EXTSIZE; 116 if (ip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) 117 flags |= FS_XFLAG_EXTSZINHERIT; 118 if (ip->i_diflags & XFS_DIFLAG_NODEFRAG) 119 flags |= FS_XFLAG_NODEFRAG; 120 if (ip->i_diflags & XFS_DIFLAG_FILESTREAM) 121 flags |= FS_XFLAG_FILESTREAM; 122 } 123 124 if (ip->i_diflags2 & XFS_DIFLAG2_ANY) { 125 if (ip->i_diflags2 & XFS_DIFLAG2_DAX) 126 flags |= FS_XFLAG_DAX; 127 if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) 128 flags |= FS_XFLAG_COWEXTSIZE; 129 } 130 131 if (xfs_inode_has_attr_fork(ip)) 132 flags |= FS_XFLAG_HASATTR; 133 return flags; 134 } 135 136 prid_t 137 xfs_get_initial_prid(struct xfs_inode *dp) 138 { 139 if (dp->i_diflags & XFS_DIFLAG_PROJINHERIT) 140 return dp->i_projid; 141 142 /* Assign to the root project by default. */ 143 return 0; 144 } 145 146 /* Propagate di_flags from a parent inode to a child inode. */ 147 static inline void 148 xfs_inode_inherit_flags( 149 struct xfs_inode *ip, 150 const struct xfs_inode *pip) 151 { 152 unsigned int di_flags = 0; 153 xfs_failaddr_t failaddr; 154 umode_t mode = VFS_I(ip)->i_mode; 155 156 if (S_ISDIR(mode)) { 157 if (pip->i_diflags & XFS_DIFLAG_RTINHERIT) 158 di_flags |= XFS_DIFLAG_RTINHERIT; 159 if (pip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) { 160 di_flags |= XFS_DIFLAG_EXTSZINHERIT; 161 ip->i_extsize = pip->i_extsize; 162 } 163 if (pip->i_diflags & XFS_DIFLAG_PROJINHERIT) 164 di_flags |= XFS_DIFLAG_PROJINHERIT; 165 } else if (S_ISREG(mode)) { 166 if ((pip->i_diflags & XFS_DIFLAG_RTINHERIT) && 167 xfs_has_realtime(ip->i_mount)) 168 di_flags |= XFS_DIFLAG_REALTIME; 169 if (pip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) { 170 di_flags |= XFS_DIFLAG_EXTSIZE; 171 ip->i_extsize = pip->i_extsize; 172 } 173 } 174 if ((pip->i_diflags & XFS_DIFLAG_NOATIME) && 175 xfs_inherit_noatime) 176 di_flags |= XFS_DIFLAG_NOATIME; 177 if ((pip->i_diflags & XFS_DIFLAG_NODUMP) && 178 xfs_inherit_nodump) 179 di_flags |= XFS_DIFLAG_NODUMP; 180 if ((pip->i_diflags & XFS_DIFLAG_SYNC) && 181 xfs_inherit_sync) 182 di_flags |= XFS_DIFLAG_SYNC; 183 if ((pip->i_diflags & XFS_DIFLAG_NOSYMLINKS) && 184 xfs_inherit_nosymlinks) 185 di_flags |= XFS_DIFLAG_NOSYMLINKS; 186 if ((pip->i_diflags & XFS_DIFLAG_NODEFRAG) && 187 xfs_inherit_nodefrag) 188 di_flags |= XFS_DIFLAG_NODEFRAG; 189 if (pip->i_diflags & XFS_DIFLAG_FILESTREAM) 190 di_flags |= XFS_DIFLAG_FILESTREAM; 191 192 ip->i_diflags |= di_flags; 193 194 /* 195 * Inode verifiers on older kernels only check that the extent size 196 * hint is an integer multiple of the rt extent size on realtime files. 197 * They did not check the hint alignment on a directory with both 198 * rtinherit and extszinherit flags set. If the misaligned hint is 199 * propagated from a directory into a new realtime file, new file 200 * allocations will fail due to math errors in the rt allocator and/or 201 * trip the verifiers. Validate the hint settings in the new file so 202 * that we don't let broken hints propagate. 203 */ 204 failaddr = xfs_inode_validate_extsize(ip->i_mount, ip->i_extsize, 205 VFS_I(ip)->i_mode, ip->i_diflags); 206 if (failaddr) { 207 ip->i_diflags &= ~(XFS_DIFLAG_EXTSIZE | 208 XFS_DIFLAG_EXTSZINHERIT); 209 ip->i_extsize = 0; 210 } 211 } 212 213 /* Propagate di_flags2 from a parent inode to a child inode. */ 214 static inline void 215 xfs_inode_inherit_flags2( 216 struct xfs_inode *ip, 217 const struct xfs_inode *pip) 218 { 219 xfs_failaddr_t failaddr; 220 221 if (pip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) { 222 ip->i_diflags2 |= XFS_DIFLAG2_COWEXTSIZE; 223 ip->i_cowextsize = pip->i_cowextsize; 224 } 225 if (pip->i_diflags2 & XFS_DIFLAG2_DAX) 226 ip->i_diflags2 |= XFS_DIFLAG2_DAX; 227 if (xfs_is_metadir_inode(pip)) 228 ip->i_diflags2 |= XFS_DIFLAG2_METADATA; 229 230 /* Don't let invalid cowextsize hints propagate. */ 231 failaddr = xfs_inode_validate_cowextsize(ip->i_mount, ip->i_cowextsize, 232 VFS_I(ip)->i_mode, ip->i_diflags, ip->i_diflags2); 233 if (failaddr) { 234 ip->i_diflags2 &= ~XFS_DIFLAG2_COWEXTSIZE; 235 ip->i_cowextsize = 0; 236 } 237 } 238 239 /* 240 * If we need to create attributes immediately after allocating the inode, 241 * initialise an empty attribute fork right now. We use the default fork offset 242 * for attributes here as we don't know exactly what size or how many 243 * attributes we might be adding. We can do this safely here because we know 244 * the data fork is completely empty and this saves us from needing to run a 245 * separate transaction to set the fork offset in the immediate future. 246 * 247 * If we have parent pointers and the caller hasn't told us that the file will 248 * never be linked into a directory tree, we /must/ create the attr fork. 249 */ 250 static inline bool 251 xfs_icreate_want_attrfork( 252 struct xfs_mount *mp, 253 const struct xfs_icreate_args *args) 254 { 255 if (args->flags & XFS_ICREATE_INIT_XATTRS) 256 return true; 257 258 if (!(args->flags & XFS_ICREATE_UNLINKABLE) && xfs_has_parent(mp)) 259 return true; 260 261 return false; 262 } 263 264 /* Initialise an inode's attributes. */ 265 void 266 xfs_inode_init( 267 struct xfs_trans *tp, 268 const struct xfs_icreate_args *args, 269 struct xfs_inode *ip) 270 { 271 struct xfs_inode *pip = args->pip; 272 struct inode *dir = pip ? VFS_I(pip) : NULL; 273 struct xfs_mount *mp = tp->t_mountp; 274 struct inode *inode = VFS_I(ip); 275 unsigned int flags; 276 int times = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG | 277 XFS_ICHGTIME_ACCESS; 278 279 if (args->flags & XFS_ICREATE_TMPFILE) 280 set_nlink(inode, 0); 281 else if (S_ISDIR(args->mode)) 282 set_nlink(inode, 2); 283 else 284 set_nlink(inode, 1); 285 inode->i_rdev = args->rdev; 286 287 if (!args->idmap || pip == NULL) { 288 /* creating a tree root, sb rooted, or detached file */ 289 inode->i_uid = GLOBAL_ROOT_UID; 290 inode->i_gid = GLOBAL_ROOT_GID; 291 ip->i_projid = 0; 292 inode->i_mode = args->mode; 293 } else { 294 /* creating a child in the directory tree */ 295 if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) { 296 inode_fsuid_set(inode, args->idmap); 297 inode->i_gid = dir->i_gid; 298 inode->i_mode = args->mode; 299 } else { 300 inode_init_owner(args->idmap, inode, dir, args->mode); 301 } 302 303 /* 304 * If the group ID of the new file does not match the effective 305 * group ID or one of the supplementary group IDs, the S_ISGID 306 * bit is cleared (and only if the irix_sgid_inherit 307 * compatibility variable is set). 308 */ 309 if (irix_sgid_inherit && (inode->i_mode & S_ISGID) && 310 !vfsgid_in_group_p(i_gid_into_vfsgid(args->idmap, inode))) 311 inode->i_mode &= ~S_ISGID; 312 313 ip->i_projid = xfs_get_initial_prid(pip); 314 } 315 316 ip->i_disk_size = 0; 317 ip->i_df.if_nextents = 0; 318 ASSERT(ip->i_nblocks == 0); 319 320 ip->i_extsize = 0; 321 ip->i_diflags = 0; 322 323 if (xfs_has_v3inodes(mp)) { 324 inode_set_iversion(inode, 1); 325 ip->i_cowextsize = 0; 326 times |= XFS_ICHGTIME_CREATE; 327 } 328 329 xfs_trans_ichgtime(tp, ip, times); 330 331 flags = XFS_ILOG_CORE; 332 switch (args->mode & S_IFMT) { 333 case S_IFIFO: 334 case S_IFCHR: 335 case S_IFBLK: 336 case S_IFSOCK: 337 ip->i_df.if_format = XFS_DINODE_FMT_DEV; 338 flags |= XFS_ILOG_DEV; 339 break; 340 case S_IFREG: 341 case S_IFDIR: 342 if (pip && (pip->i_diflags & XFS_DIFLAG_ANY)) 343 xfs_inode_inherit_flags(ip, pip); 344 if (pip && (pip->i_diflags2 & XFS_DIFLAG2_ANY)) 345 xfs_inode_inherit_flags2(ip, pip); 346 fallthrough; 347 case S_IFLNK: 348 ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS; 349 ip->i_df.if_bytes = 0; 350 ip->i_df.if_data = NULL; 351 break; 352 default: 353 ASSERT(0); 354 } 355 356 if (xfs_icreate_want_attrfork(mp, args)) { 357 ip->i_forkoff = xfs_default_attroffset(ip) >> 3; 358 xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0); 359 360 if (!xfs_has_attr(mp)) { 361 spin_lock(&mp->m_sb_lock); 362 xfs_add_attr(mp); 363 spin_unlock(&mp->m_sb_lock); 364 xfs_log_sb(tp); 365 } 366 } 367 368 xfs_trans_log_inode(tp, ip, flags); 369 } 370 371 /* 372 * In-Core Unlinked List Lookups 373 * ============================= 374 * 375 * Every inode is supposed to be reachable from some other piece of metadata 376 * with the exception of the root directory. Inodes with a connection to a 377 * file descriptor but not linked from anywhere in the on-disk directory tree 378 * are collectively known as unlinked inodes, though the filesystem itself 379 * maintains links to these inodes so that on-disk metadata are consistent. 380 * 381 * XFS implements a per-AG on-disk hash table of unlinked inodes. The AGI 382 * header contains a number of buckets that point to an inode, and each inode 383 * record has a pointer to the next inode in the hash chain. This 384 * singly-linked list causes scaling problems in the iunlink remove function 385 * because we must walk that list to find the inode that points to the inode 386 * being removed from the unlinked hash bucket list. 387 * 388 * Hence we keep an in-memory double linked list to link each inode on an 389 * unlinked list. Because there are 64 unlinked lists per AGI, keeping pointer 390 * based lists would require having 64 list heads in the perag, one for each 391 * list. This is expensive in terms of memory (think millions of AGs) and cache 392 * misses on lookups. Instead, use the fact that inodes on the unlinked list 393 * must be referenced at the VFS level to keep them on the list and hence we 394 * have an existence guarantee for inodes on the unlinked list. 395 * 396 * Given we have an existence guarantee, we can use lockless inode cache lookups 397 * to resolve aginos to xfs inodes. This means we only need 8 bytes per inode 398 * for the double linked unlinked list, and we don't need any extra locking to 399 * keep the list safe as all manipulations are done under the AGI buffer lock. 400 * Keeping the list up to date does not require memory allocation, just finding 401 * the XFS inode and updating the next/prev unlinked list aginos. 402 */ 403 404 /* 405 * Update the prev pointer of the next agino. Returns -ENOLINK if the inode 406 * is not in cache. 407 */ 408 static int 409 xfs_iunlink_update_backref( 410 struct xfs_perag *pag, 411 xfs_agino_t prev_agino, 412 xfs_agino_t next_agino) 413 { 414 struct xfs_inode *ip; 415 416 /* No update necessary if we are at the end of the list. */ 417 if (next_agino == NULLAGINO) 418 return 0; 419 420 ip = xfs_iunlink_lookup(pag, next_agino); 421 if (!ip) 422 return -ENOLINK; 423 424 ip->i_prev_unlinked = prev_agino; 425 return 0; 426 } 427 428 /* 429 * Point the AGI unlinked bucket at an inode and log the results. The caller 430 * is responsible for validating the old value. 431 */ 432 STATIC int 433 xfs_iunlink_update_bucket( 434 struct xfs_trans *tp, 435 struct xfs_perag *pag, 436 struct xfs_buf *agibp, 437 unsigned int bucket_index, 438 xfs_agino_t new_agino) 439 { 440 struct xfs_agi *agi = agibp->b_addr; 441 xfs_agino_t old_value; 442 int offset; 443 444 ASSERT(xfs_verify_agino_or_null(pag, new_agino)); 445 446 old_value = be32_to_cpu(agi->agi_unlinked[bucket_index]); 447 trace_xfs_iunlink_update_bucket(pag, bucket_index, old_value, 448 new_agino); 449 450 /* 451 * We should never find the head of the list already set to the value 452 * passed in because either we're adding or removing ourselves from the 453 * head of the list. 454 */ 455 if (old_value == new_agino) { 456 xfs_buf_mark_corrupt(agibp); 457 xfs_ag_mark_sick(pag, XFS_SICK_AG_AGI); 458 return -EFSCORRUPTED; 459 } 460 461 agi->agi_unlinked[bucket_index] = cpu_to_be32(new_agino); 462 offset = offsetof(struct xfs_agi, agi_unlinked) + 463 (sizeof(xfs_agino_t) * bucket_index); 464 xfs_trans_log_buf(tp, agibp, offset, offset + sizeof(xfs_agino_t) - 1); 465 return 0; 466 } 467 468 static int 469 xfs_iunlink_insert_inode( 470 struct xfs_trans *tp, 471 struct xfs_perag *pag, 472 struct xfs_buf *agibp, 473 struct xfs_inode *ip) 474 { 475 struct xfs_mount *mp = tp->t_mountp; 476 struct xfs_agi *agi = agibp->b_addr; 477 xfs_agino_t next_agino; 478 xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino); 479 short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS; 480 int error; 481 482 /* 483 * Get the index into the agi hash table for the list this inode will 484 * go on. Make sure the pointer isn't garbage and that this inode 485 * isn't already on the list. 486 */ 487 next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]); 488 if (next_agino == agino || 489 !xfs_verify_agino_or_null(pag, next_agino)) { 490 xfs_buf_mark_corrupt(agibp); 491 xfs_ag_mark_sick(pag, XFS_SICK_AG_AGI); 492 return -EFSCORRUPTED; 493 } 494 495 /* 496 * Update the prev pointer in the next inode to point back to this 497 * inode. 498 */ 499 error = xfs_iunlink_update_backref(pag, agino, next_agino); 500 if (error == -ENOLINK) 501 error = xfs_iunlink_reload_next(tp, agibp, agino, next_agino); 502 if (error) 503 return error; 504 505 if (next_agino != NULLAGINO) { 506 /* 507 * There is already another inode in the bucket, so point this 508 * inode to the current head of the list. 509 */ 510 error = xfs_iunlink_log_inode(tp, ip, pag, next_agino); 511 if (error) 512 return error; 513 ip->i_next_unlinked = next_agino; 514 } 515 516 /* Point the head of the list to point to this inode. */ 517 ip->i_prev_unlinked = NULLAGINO; 518 return xfs_iunlink_update_bucket(tp, pag, agibp, bucket_index, agino); 519 } 520 521 /* 522 * This is called when the inode's link count has gone to 0 or we are creating 523 * a tmpfile via O_TMPFILE. The inode @ip must have nlink == 0. 524 * 525 * We place the on-disk inode on a list in the AGI. It will be pulled from this 526 * list when the inode is freed. 527 */ 528 int 529 xfs_iunlink( 530 struct xfs_trans *tp, 531 struct xfs_inode *ip) 532 { 533 struct xfs_mount *mp = tp->t_mountp; 534 struct xfs_perag *pag; 535 struct xfs_buf *agibp; 536 int error; 537 538 ASSERT(VFS_I(ip)->i_nlink == 0); 539 ASSERT(VFS_I(ip)->i_mode != 0); 540 trace_xfs_iunlink(ip); 541 542 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); 543 544 /* Get the agi buffer first. It ensures lock ordering on the list. */ 545 error = xfs_read_agi(pag, tp, 0, &agibp); 546 if (error) 547 goto out; 548 549 error = xfs_iunlink_insert_inode(tp, pag, agibp, ip); 550 out: 551 xfs_perag_put(pag); 552 return error; 553 } 554 555 static int 556 xfs_iunlink_remove_inode( 557 struct xfs_trans *tp, 558 struct xfs_perag *pag, 559 struct xfs_buf *agibp, 560 struct xfs_inode *ip) 561 { 562 struct xfs_mount *mp = tp->t_mountp; 563 struct xfs_agi *agi = agibp->b_addr; 564 xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino); 565 xfs_agino_t head_agino; 566 short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS; 567 int error; 568 569 trace_xfs_iunlink_remove(ip); 570 571 /* 572 * Get the index into the agi hash table for the list this inode will 573 * go on. Make sure the head pointer isn't garbage. 574 */ 575 head_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]); 576 if (!xfs_verify_agino(pag, head_agino)) { 577 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, 578 agi, sizeof(*agi)); 579 xfs_ag_mark_sick(pag, XFS_SICK_AG_AGI); 580 return -EFSCORRUPTED; 581 } 582 583 /* 584 * Set our inode's next_unlinked pointer to NULL and then return 585 * the old pointer value so that we can update whatever was previous 586 * to us in the list to point to whatever was next in the list. 587 */ 588 error = xfs_iunlink_log_inode(tp, ip, pag, NULLAGINO); 589 if (error) 590 return error; 591 592 /* 593 * Update the prev pointer in the next inode to point back to previous 594 * inode in the chain. 595 */ 596 error = xfs_iunlink_update_backref(pag, ip->i_prev_unlinked, 597 ip->i_next_unlinked); 598 if (error == -ENOLINK) 599 error = xfs_iunlink_reload_next(tp, agibp, ip->i_prev_unlinked, 600 ip->i_next_unlinked); 601 if (error) 602 return error; 603 604 if (head_agino != agino) { 605 struct xfs_inode *prev_ip; 606 607 prev_ip = xfs_iunlink_lookup(pag, ip->i_prev_unlinked); 608 if (!prev_ip) { 609 xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE); 610 return -EFSCORRUPTED; 611 } 612 613 error = xfs_iunlink_log_inode(tp, prev_ip, pag, 614 ip->i_next_unlinked); 615 prev_ip->i_next_unlinked = ip->i_next_unlinked; 616 } else { 617 /* Point the head of the list to the next unlinked inode. */ 618 error = xfs_iunlink_update_bucket(tp, pag, agibp, bucket_index, 619 ip->i_next_unlinked); 620 } 621 622 ip->i_next_unlinked = NULLAGINO; 623 ip->i_prev_unlinked = 0; 624 return error; 625 } 626 627 /* 628 * Pull the on-disk inode from the AGI unlinked list. 629 */ 630 int 631 xfs_iunlink_remove( 632 struct xfs_trans *tp, 633 struct xfs_perag *pag, 634 struct xfs_inode *ip) 635 { 636 struct xfs_buf *agibp; 637 int error; 638 639 trace_xfs_iunlink_remove(ip); 640 641 /* Get the agi buffer first. It ensures lock ordering on the list. */ 642 error = xfs_read_agi(pag, tp, 0, &agibp); 643 if (error) 644 return error; 645 646 return xfs_iunlink_remove_inode(tp, pag, agibp, ip); 647 } 648 649 /* 650 * Decrement the link count on an inode & log the change. If this causes the 651 * link count to go to zero, move the inode to AGI unlinked list so that it can 652 * be freed when the last active reference goes away via xfs_inactive(). 653 */ 654 int 655 xfs_droplink( 656 struct xfs_trans *tp, 657 struct xfs_inode *ip) 658 { 659 struct inode *inode = VFS_I(ip); 660 661 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG); 662 663 if (inode->i_nlink == 0) { 664 xfs_info_ratelimited(tp->t_mountp, 665 "Inode 0x%llx link count dropped below zero. Pinning link count.", 666 ip->i_ino); 667 set_nlink(inode, XFS_NLINK_PINNED); 668 } 669 if (inode->i_nlink != XFS_NLINK_PINNED) 670 drop_nlink(inode); 671 672 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); 673 674 if (inode->i_nlink) 675 return 0; 676 677 return xfs_iunlink(tp, ip); 678 } 679 680 /* 681 * Increment the link count on an inode & log the change. 682 */ 683 void 684 xfs_bumplink( 685 struct xfs_trans *tp, 686 struct xfs_inode *ip) 687 { 688 struct inode *inode = VFS_I(ip); 689 690 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG); 691 692 if (inode->i_nlink == XFS_NLINK_PINNED - 1) 693 xfs_info_ratelimited(tp->t_mountp, 694 "Inode 0x%llx link count exceeded maximum. Pinning link count.", 695 ip->i_ino); 696 if (inode->i_nlink != XFS_NLINK_PINNED) 697 inc_nlink(inode); 698 699 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); 700 } 701 702 /* Free an inode in the ondisk index and zero it out. */ 703 int 704 xfs_inode_uninit( 705 struct xfs_trans *tp, 706 struct xfs_perag *pag, 707 struct xfs_inode *ip, 708 struct xfs_icluster *xic) 709 { 710 struct xfs_mount *mp = ip->i_mount; 711 int error; 712 713 /* 714 * Free the inode first so that we guarantee that the AGI lock is going 715 * to be taken before we remove the inode from the unlinked list. This 716 * makes the AGI lock -> unlinked list modification order the same as 717 * used in O_TMPFILE creation. 718 */ 719 error = xfs_difree(tp, pag, ip->i_ino, xic); 720 if (error) 721 return error; 722 723 error = xfs_iunlink_remove(tp, pag, ip); 724 if (error) 725 return error; 726 727 /* 728 * Free any local-format data sitting around before we reset the 729 * data fork to extents format. Note that the attr fork data has 730 * already been freed by xfs_attr_inactive. 731 */ 732 if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL) { 733 kfree(ip->i_df.if_data); 734 ip->i_df.if_data = NULL; 735 ip->i_df.if_bytes = 0; 736 } 737 738 VFS_I(ip)->i_mode = 0; /* mark incore inode as free */ 739 ip->i_diflags = 0; 740 ip->i_diflags2 = mp->m_ino_geo.new_diflags2; 741 ip->i_forkoff = 0; /* mark the attr fork not in use */ 742 ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS; 743 744 /* 745 * Bump the generation count so no one will be confused 746 * by reincarnations of this inode. 747 */ 748 VFS_I(ip)->i_generation++; 749 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); 750 return 0; 751 } 752