| 1 | /* |
| 2 | * Copyright (c) 2000-2005 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_format.h" |
| 21 | #include "xfs_log_format.h" |
| 22 | #include "xfs_trans_resv.h" |
| 23 | #include "xfs_sb.h" |
| 24 | #include "xfs_mount.h" |
| 25 | #include "xfs_inode.h" |
| 26 | #include "xfs_error.h" |
| 27 | #include "xfs_trans.h" |
| 28 | #include "xfs_trans_priv.h" |
| 29 | #include "xfs_inode_item.h" |
| 30 | #include "xfs_quota.h" |
| 31 | #include "xfs_trace.h" |
| 32 | #include "xfs_icache.h" |
| 33 | #include "xfs_bmap_util.h" |
| 34 | #include "xfs_dquot_item.h" |
| 35 | #include "xfs_dquot.h" |
| 36 | |
| 37 | #include <linux/kthread.h> |
| 38 | #include <linux/freezer.h> |
| 39 | |
| 40 | STATIC void __xfs_inode_clear_reclaim_tag(struct xfs_mount *mp, |
| 41 | struct xfs_perag *pag, struct xfs_inode *ip); |
| 42 | |
| 43 | /* |
| 44 | * Allocate and initialise an xfs_inode. |
| 45 | */ |
| 46 | struct xfs_inode * |
| 47 | xfs_inode_alloc( |
| 48 | struct xfs_mount *mp, |
| 49 | xfs_ino_t ino) |
| 50 | { |
| 51 | struct xfs_inode *ip; |
| 52 | |
| 53 | /* |
| 54 | * if this didn't occur in transactions, we could use |
| 55 | * KM_MAYFAIL and return NULL here on ENOMEM. Set the |
| 56 | * code up to do this anyway. |
| 57 | */ |
| 58 | ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP); |
| 59 | if (!ip) |
| 60 | return NULL; |
| 61 | if (inode_init_always(mp->m_super, VFS_I(ip))) { |
| 62 | kmem_zone_free(xfs_inode_zone, ip); |
| 63 | return NULL; |
| 64 | } |
| 65 | |
| 66 | /* VFS doesn't initialise i_mode! */ |
| 67 | VFS_I(ip)->i_mode = 0; |
| 68 | |
| 69 | XFS_STATS_INC(mp, vn_active); |
| 70 | ASSERT(atomic_read(&ip->i_pincount) == 0); |
| 71 | ASSERT(!spin_is_locked(&ip->i_flags_lock)); |
| 72 | ASSERT(!xfs_isiflocked(ip)); |
| 73 | ASSERT(ip->i_ino == 0); |
| 74 | |
| 75 | mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino); |
| 76 | |
| 77 | /* initialise the xfs inode */ |
| 78 | ip->i_ino = ino; |
| 79 | ip->i_mount = mp; |
| 80 | memset(&ip->i_imap, 0, sizeof(struct xfs_imap)); |
| 81 | ip->i_afp = NULL; |
| 82 | memset(&ip->i_df, 0, sizeof(xfs_ifork_t)); |
| 83 | ip->i_flags = 0; |
| 84 | ip->i_delayed_blks = 0; |
| 85 | memset(&ip->i_d, 0, sizeof(ip->i_d)); |
| 86 | |
| 87 | return ip; |
| 88 | } |
| 89 | |
| 90 | STATIC void |
| 91 | xfs_inode_free_callback( |
| 92 | struct rcu_head *head) |
| 93 | { |
| 94 | struct inode *inode = container_of(head, struct inode, i_rcu); |
| 95 | struct xfs_inode *ip = XFS_I(inode); |
| 96 | |
| 97 | kmem_zone_free(xfs_inode_zone, ip); |
| 98 | } |
| 99 | |
| 100 | void |
| 101 | xfs_inode_free( |
| 102 | struct xfs_inode *ip) |
| 103 | { |
| 104 | switch (VFS_I(ip)->i_mode & S_IFMT) { |
| 105 | case S_IFREG: |
| 106 | case S_IFDIR: |
| 107 | case S_IFLNK: |
| 108 | xfs_idestroy_fork(ip, XFS_DATA_FORK); |
| 109 | break; |
| 110 | } |
| 111 | |
| 112 | if (ip->i_afp) |
| 113 | xfs_idestroy_fork(ip, XFS_ATTR_FORK); |
| 114 | |
| 115 | if (ip->i_itemp) { |
| 116 | ASSERT(!(ip->i_itemp->ili_item.li_flags & XFS_LI_IN_AIL)); |
| 117 | xfs_inode_item_destroy(ip); |
| 118 | ip->i_itemp = NULL; |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Because we use RCU freeing we need to ensure the inode always |
| 123 | * appears to be reclaimed with an invalid inode number when in the |
| 124 | * free state. The ip->i_flags_lock provides the barrier against lookup |
| 125 | * races. |
| 126 | */ |
| 127 | spin_lock(&ip->i_flags_lock); |
| 128 | ip->i_flags = XFS_IRECLAIM; |
| 129 | ip->i_ino = 0; |
| 130 | spin_unlock(&ip->i_flags_lock); |
| 131 | |
| 132 | /* asserts to verify all state is correct here */ |
| 133 | ASSERT(atomic_read(&ip->i_pincount) == 0); |
| 134 | ASSERT(!xfs_isiflocked(ip)); |
| 135 | XFS_STATS_DEC(ip->i_mount, vn_active); |
| 136 | |
| 137 | call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback); |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * When we recycle a reclaimable inode, we need to re-initialise the VFS inode |
| 142 | * part of the structure. This is made more complex by the fact we store |
| 143 | * information about the on-disk values in the VFS inode and so we can't just |
| 144 | * overwrite the values unconditionally. Hence we save the parameters we |
| 145 | * need to retain across reinitialisation, and rewrite them into the VFS inode |
| 146 | * after reinitialisation even if it fails. |
| 147 | */ |
| 148 | static int |
| 149 | xfs_reinit_inode( |
| 150 | struct xfs_mount *mp, |
| 151 | struct inode *inode) |
| 152 | { |
| 153 | int error; |
| 154 | uint32_t nlink = inode->i_nlink; |
| 155 | uint32_t generation = inode->i_generation; |
| 156 | uint64_t version = inode->i_version; |
| 157 | umode_t mode = inode->i_mode; |
| 158 | |
| 159 | error = inode_init_always(mp->m_super, inode); |
| 160 | |
| 161 | set_nlink(inode, nlink); |
| 162 | inode->i_generation = generation; |
| 163 | inode->i_version = version; |
| 164 | inode->i_mode = mode; |
| 165 | return error; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Check the validity of the inode we just found it the cache |
| 170 | */ |
| 171 | static int |
| 172 | xfs_iget_cache_hit( |
| 173 | struct xfs_perag *pag, |
| 174 | struct xfs_inode *ip, |
| 175 | xfs_ino_t ino, |
| 176 | int flags, |
| 177 | int lock_flags) __releases(RCU) |
| 178 | { |
| 179 | struct inode *inode = VFS_I(ip); |
| 180 | struct xfs_mount *mp = ip->i_mount; |
| 181 | int error; |
| 182 | |
| 183 | /* |
| 184 | * check for re-use of an inode within an RCU grace period due to the |
| 185 | * radix tree nodes not being updated yet. We monitor for this by |
| 186 | * setting the inode number to zero before freeing the inode structure. |
| 187 | * If the inode has been reallocated and set up, then the inode number |
| 188 | * will not match, so check for that, too. |
| 189 | */ |
| 190 | spin_lock(&ip->i_flags_lock); |
| 191 | if (ip->i_ino != ino) { |
| 192 | trace_xfs_iget_skip(ip); |
| 193 | XFS_STATS_INC(mp, xs_ig_frecycle); |
| 194 | error = -EAGAIN; |
| 195 | goto out_error; |
| 196 | } |
| 197 | |
| 198 | |
| 199 | /* |
| 200 | * If we are racing with another cache hit that is currently |
| 201 | * instantiating this inode or currently recycling it out of |
| 202 | * reclaimabe state, wait for the initialisation to complete |
| 203 | * before continuing. |
| 204 | * |
| 205 | * XXX(hch): eventually we should do something equivalent to |
| 206 | * wait_on_inode to wait for these flags to be cleared |
| 207 | * instead of polling for it. |
| 208 | */ |
| 209 | if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) { |
| 210 | trace_xfs_iget_skip(ip); |
| 211 | XFS_STATS_INC(mp, xs_ig_frecycle); |
| 212 | error = -EAGAIN; |
| 213 | goto out_error; |
| 214 | } |
| 215 | |
| 216 | /* |
| 217 | * If lookup is racing with unlink return an error immediately. |
| 218 | */ |
| 219 | if (VFS_I(ip)->i_mode == 0 && !(flags & XFS_IGET_CREATE)) { |
| 220 | error = -ENOENT; |
| 221 | goto out_error; |
| 222 | } |
| 223 | |
| 224 | /* |
| 225 | * If IRECLAIMABLE is set, we've torn down the VFS inode already. |
| 226 | * Need to carefully get it back into useable state. |
| 227 | */ |
| 228 | if (ip->i_flags & XFS_IRECLAIMABLE) { |
| 229 | trace_xfs_iget_reclaim(ip); |
| 230 | |
| 231 | /* |
| 232 | * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode |
| 233 | * from stomping over us while we recycle the inode. We can't |
| 234 | * clear the radix tree reclaimable tag yet as it requires |
| 235 | * pag_ici_lock to be held exclusive. |
| 236 | */ |
| 237 | ip->i_flags |= XFS_IRECLAIM; |
| 238 | |
| 239 | spin_unlock(&ip->i_flags_lock); |
| 240 | rcu_read_unlock(); |
| 241 | |
| 242 | error = xfs_reinit_inode(mp, inode); |
| 243 | if (error) { |
| 244 | /* |
| 245 | * Re-initializing the inode failed, and we are in deep |
| 246 | * trouble. Try to re-add it to the reclaim list. |
| 247 | */ |
| 248 | rcu_read_lock(); |
| 249 | spin_lock(&ip->i_flags_lock); |
| 250 | |
| 251 | ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM); |
| 252 | ASSERT(ip->i_flags & XFS_IRECLAIMABLE); |
| 253 | trace_xfs_iget_reclaim_fail(ip); |
| 254 | goto out_error; |
| 255 | } |
| 256 | |
| 257 | spin_lock(&pag->pag_ici_lock); |
| 258 | spin_lock(&ip->i_flags_lock); |
| 259 | |
| 260 | /* |
| 261 | * Clear the per-lifetime state in the inode as we are now |
| 262 | * effectively a new inode and need to return to the initial |
| 263 | * state before reuse occurs. |
| 264 | */ |
| 265 | ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS; |
| 266 | ip->i_flags |= XFS_INEW; |
| 267 | __xfs_inode_clear_reclaim_tag(mp, pag, ip); |
| 268 | inode->i_state = I_NEW; |
| 269 | |
| 270 | ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock)); |
| 271 | mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino); |
| 272 | |
| 273 | spin_unlock(&ip->i_flags_lock); |
| 274 | spin_unlock(&pag->pag_ici_lock); |
| 275 | } else { |
| 276 | /* If the VFS inode is being torn down, pause and try again. */ |
| 277 | if (!igrab(inode)) { |
| 278 | trace_xfs_iget_skip(ip); |
| 279 | error = -EAGAIN; |
| 280 | goto out_error; |
| 281 | } |
| 282 | |
| 283 | /* We've got a live one. */ |
| 284 | spin_unlock(&ip->i_flags_lock); |
| 285 | rcu_read_unlock(); |
| 286 | trace_xfs_iget_hit(ip); |
| 287 | } |
| 288 | |
| 289 | if (lock_flags != 0) |
| 290 | xfs_ilock(ip, lock_flags); |
| 291 | |
| 292 | xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE); |
| 293 | XFS_STATS_INC(mp, xs_ig_found); |
| 294 | |
| 295 | return 0; |
| 296 | |
| 297 | out_error: |
| 298 | spin_unlock(&ip->i_flags_lock); |
| 299 | rcu_read_unlock(); |
| 300 | return error; |
| 301 | } |
| 302 | |
| 303 | |
| 304 | static int |
| 305 | xfs_iget_cache_miss( |
| 306 | struct xfs_mount *mp, |
| 307 | struct xfs_perag *pag, |
| 308 | xfs_trans_t *tp, |
| 309 | xfs_ino_t ino, |
| 310 | struct xfs_inode **ipp, |
| 311 | int flags, |
| 312 | int lock_flags) |
| 313 | { |
| 314 | struct xfs_inode *ip; |
| 315 | int error; |
| 316 | xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); |
| 317 | int iflags; |
| 318 | |
| 319 | ip = xfs_inode_alloc(mp, ino); |
| 320 | if (!ip) |
| 321 | return -ENOMEM; |
| 322 | |
| 323 | error = xfs_iread(mp, tp, ip, flags); |
| 324 | if (error) |
| 325 | goto out_destroy; |
| 326 | |
| 327 | trace_xfs_iget_miss(ip); |
| 328 | |
| 329 | if ((VFS_I(ip)->i_mode == 0) && !(flags & XFS_IGET_CREATE)) { |
| 330 | error = -ENOENT; |
| 331 | goto out_destroy; |
| 332 | } |
| 333 | |
| 334 | /* |
| 335 | * Preload the radix tree so we can insert safely under the |
| 336 | * write spinlock. Note that we cannot sleep inside the preload |
| 337 | * region. Since we can be called from transaction context, don't |
| 338 | * recurse into the file system. |
| 339 | */ |
| 340 | if (radix_tree_preload(GFP_NOFS)) { |
| 341 | error = -EAGAIN; |
| 342 | goto out_destroy; |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Because the inode hasn't been added to the radix-tree yet it can't |
| 347 | * be found by another thread, so we can do the non-sleeping lock here. |
| 348 | */ |
| 349 | if (lock_flags) { |
| 350 | if (!xfs_ilock_nowait(ip, lock_flags)) |
| 351 | BUG(); |
| 352 | } |
| 353 | |
| 354 | /* |
| 355 | * These values must be set before inserting the inode into the radix |
| 356 | * tree as the moment it is inserted a concurrent lookup (allowed by the |
| 357 | * RCU locking mechanism) can find it and that lookup must see that this |
| 358 | * is an inode currently under construction (i.e. that XFS_INEW is set). |
| 359 | * The ip->i_flags_lock that protects the XFS_INEW flag forms the |
| 360 | * memory barrier that ensures this detection works correctly at lookup |
| 361 | * time. |
| 362 | */ |
| 363 | iflags = XFS_INEW; |
| 364 | if (flags & XFS_IGET_DONTCACHE) |
| 365 | iflags |= XFS_IDONTCACHE; |
| 366 | ip->i_udquot = NULL; |
| 367 | ip->i_gdquot = NULL; |
| 368 | ip->i_pdquot = NULL; |
| 369 | xfs_iflags_set(ip, iflags); |
| 370 | |
| 371 | /* insert the new inode */ |
| 372 | spin_lock(&pag->pag_ici_lock); |
| 373 | error = radix_tree_insert(&pag->pag_ici_root, agino, ip); |
| 374 | if (unlikely(error)) { |
| 375 | WARN_ON(error != -EEXIST); |
| 376 | XFS_STATS_INC(mp, xs_ig_dup); |
| 377 | error = -EAGAIN; |
| 378 | goto out_preload_end; |
| 379 | } |
| 380 | spin_unlock(&pag->pag_ici_lock); |
| 381 | radix_tree_preload_end(); |
| 382 | |
| 383 | *ipp = ip; |
| 384 | return 0; |
| 385 | |
| 386 | out_preload_end: |
| 387 | spin_unlock(&pag->pag_ici_lock); |
| 388 | radix_tree_preload_end(); |
| 389 | if (lock_flags) |
| 390 | xfs_iunlock(ip, lock_flags); |
| 391 | out_destroy: |
| 392 | __destroy_inode(VFS_I(ip)); |
| 393 | xfs_inode_free(ip); |
| 394 | return error; |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Look up an inode by number in the given file system. |
| 399 | * The inode is looked up in the cache held in each AG. |
| 400 | * If the inode is found in the cache, initialise the vfs inode |
| 401 | * if necessary. |
| 402 | * |
| 403 | * If it is not in core, read it in from the file system's device, |
| 404 | * add it to the cache and initialise the vfs inode. |
| 405 | * |
| 406 | * The inode is locked according to the value of the lock_flags parameter. |
| 407 | * This flag parameter indicates how and if the inode's IO lock and inode lock |
| 408 | * should be taken. |
| 409 | * |
| 410 | * mp -- the mount point structure for the current file system. It points |
| 411 | * to the inode hash table. |
| 412 | * tp -- a pointer to the current transaction if there is one. This is |
| 413 | * simply passed through to the xfs_iread() call. |
| 414 | * ino -- the number of the inode desired. This is the unique identifier |
| 415 | * within the file system for the inode being requested. |
| 416 | * lock_flags -- flags indicating how to lock the inode. See the comment |
| 417 | * for xfs_ilock() for a list of valid values. |
| 418 | */ |
| 419 | int |
| 420 | xfs_iget( |
| 421 | xfs_mount_t *mp, |
| 422 | xfs_trans_t *tp, |
| 423 | xfs_ino_t ino, |
| 424 | uint flags, |
| 425 | uint lock_flags, |
| 426 | xfs_inode_t **ipp) |
| 427 | { |
| 428 | xfs_inode_t *ip; |
| 429 | int error; |
| 430 | xfs_perag_t *pag; |
| 431 | xfs_agino_t agino; |
| 432 | |
| 433 | /* |
| 434 | * xfs_reclaim_inode() uses the ILOCK to ensure an inode |
| 435 | * doesn't get freed while it's being referenced during a |
| 436 | * radix tree traversal here. It assumes this function |
| 437 | * aqcuires only the ILOCK (and therefore it has no need to |
| 438 | * involve the IOLOCK in this synchronization). |
| 439 | */ |
| 440 | ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0); |
| 441 | |
| 442 | /* reject inode numbers outside existing AGs */ |
| 443 | if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount) |
| 444 | return -EINVAL; |
| 445 | |
| 446 | XFS_STATS_INC(mp, xs_ig_attempts); |
| 447 | |
| 448 | /* get the perag structure and ensure that it's inode capable */ |
| 449 | pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino)); |
| 450 | agino = XFS_INO_TO_AGINO(mp, ino); |
| 451 | |
| 452 | again: |
| 453 | error = 0; |
| 454 | rcu_read_lock(); |
| 455 | ip = radix_tree_lookup(&pag->pag_ici_root, agino); |
| 456 | |
| 457 | if (ip) { |
| 458 | error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags); |
| 459 | if (error) |
| 460 | goto out_error_or_again; |
| 461 | } else { |
| 462 | rcu_read_unlock(); |
| 463 | XFS_STATS_INC(mp, xs_ig_missed); |
| 464 | |
| 465 | error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, |
| 466 | flags, lock_flags); |
| 467 | if (error) |
| 468 | goto out_error_or_again; |
| 469 | } |
| 470 | xfs_perag_put(pag); |
| 471 | |
| 472 | *ipp = ip; |
| 473 | |
| 474 | /* |
| 475 | * If we have a real type for an on-disk inode, we can setup the inode |
| 476 | * now. If it's a new inode being created, xfs_ialloc will handle it. |
| 477 | */ |
| 478 | if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0) |
| 479 | xfs_setup_existing_inode(ip); |
| 480 | return 0; |
| 481 | |
| 482 | out_error_or_again: |
| 483 | if (error == -EAGAIN) { |
| 484 | delay(1); |
| 485 | goto again; |
| 486 | } |
| 487 | xfs_perag_put(pag); |
| 488 | return error; |
| 489 | } |
| 490 | |
| 491 | /* |
| 492 | * The inode lookup is done in batches to keep the amount of lock traffic and |
| 493 | * radix tree lookups to a minimum. The batch size is a trade off between |
| 494 | * lookup reduction and stack usage. This is in the reclaim path, so we can't |
| 495 | * be too greedy. |
| 496 | */ |
| 497 | #define XFS_LOOKUP_BATCH 32 |
| 498 | |
| 499 | STATIC int |
| 500 | xfs_inode_ag_walk_grab( |
| 501 | struct xfs_inode *ip) |
| 502 | { |
| 503 | struct inode *inode = VFS_I(ip); |
| 504 | |
| 505 | ASSERT(rcu_read_lock_held()); |
| 506 | |
| 507 | /* |
| 508 | * check for stale RCU freed inode |
| 509 | * |
| 510 | * If the inode has been reallocated, it doesn't matter if it's not in |
| 511 | * the AG we are walking - we are walking for writeback, so if it |
| 512 | * passes all the "valid inode" checks and is dirty, then we'll write |
| 513 | * it back anyway. If it has been reallocated and still being |
| 514 | * initialised, the XFS_INEW check below will catch it. |
| 515 | */ |
| 516 | spin_lock(&ip->i_flags_lock); |
| 517 | if (!ip->i_ino) |
| 518 | goto out_unlock_noent; |
| 519 | |
| 520 | /* avoid new or reclaimable inodes. Leave for reclaim code to flush */ |
| 521 | if (__xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM)) |
| 522 | goto out_unlock_noent; |
| 523 | spin_unlock(&ip->i_flags_lock); |
| 524 | |
| 525 | /* nothing to sync during shutdown */ |
| 526 | if (XFS_FORCED_SHUTDOWN(ip->i_mount)) |
| 527 | return -EFSCORRUPTED; |
| 528 | |
| 529 | /* If we can't grab the inode, it must on it's way to reclaim. */ |
| 530 | if (!igrab(inode)) |
| 531 | return -ENOENT; |
| 532 | |
| 533 | /* inode is valid */ |
| 534 | return 0; |
| 535 | |
| 536 | out_unlock_noent: |
| 537 | spin_unlock(&ip->i_flags_lock); |
| 538 | return -ENOENT; |
| 539 | } |
| 540 | |
| 541 | STATIC int |
| 542 | xfs_inode_ag_walk( |
| 543 | struct xfs_mount *mp, |
| 544 | struct xfs_perag *pag, |
| 545 | int (*execute)(struct xfs_inode *ip, int flags, |
| 546 | void *args), |
| 547 | int flags, |
| 548 | void *args, |
| 549 | int tag) |
| 550 | { |
| 551 | uint32_t first_index; |
| 552 | int last_error = 0; |
| 553 | int skipped; |
| 554 | int done; |
| 555 | int nr_found; |
| 556 | |
| 557 | restart: |
| 558 | done = 0; |
| 559 | skipped = 0; |
| 560 | first_index = 0; |
| 561 | nr_found = 0; |
| 562 | do { |
| 563 | struct xfs_inode *batch[XFS_LOOKUP_BATCH]; |
| 564 | int error = 0; |
| 565 | int i; |
| 566 | |
| 567 | rcu_read_lock(); |
| 568 | |
| 569 | if (tag == -1) |
| 570 | nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, |
| 571 | (void **)batch, first_index, |
| 572 | XFS_LOOKUP_BATCH); |
| 573 | else |
| 574 | nr_found = radix_tree_gang_lookup_tag( |
| 575 | &pag->pag_ici_root, |
| 576 | (void **) batch, first_index, |
| 577 | XFS_LOOKUP_BATCH, tag); |
| 578 | |
| 579 | if (!nr_found) { |
| 580 | rcu_read_unlock(); |
| 581 | break; |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * Grab the inodes before we drop the lock. if we found |
| 586 | * nothing, nr == 0 and the loop will be skipped. |
| 587 | */ |
| 588 | for (i = 0; i < nr_found; i++) { |
| 589 | struct xfs_inode *ip = batch[i]; |
| 590 | |
| 591 | if (done || xfs_inode_ag_walk_grab(ip)) |
| 592 | batch[i] = NULL; |
| 593 | |
| 594 | /* |
| 595 | * Update the index for the next lookup. Catch |
| 596 | * overflows into the next AG range which can occur if |
| 597 | * we have inodes in the last block of the AG and we |
| 598 | * are currently pointing to the last inode. |
| 599 | * |
| 600 | * Because we may see inodes that are from the wrong AG |
| 601 | * due to RCU freeing and reallocation, only update the |
| 602 | * index if it lies in this AG. It was a race that lead |
| 603 | * us to see this inode, so another lookup from the |
| 604 | * same index will not find it again. |
| 605 | */ |
| 606 | if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno) |
| 607 | continue; |
| 608 | first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); |
| 609 | if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) |
| 610 | done = 1; |
| 611 | } |
| 612 | |
| 613 | /* unlock now we've grabbed the inodes. */ |
| 614 | rcu_read_unlock(); |
| 615 | |
| 616 | for (i = 0; i < nr_found; i++) { |
| 617 | if (!batch[i]) |
| 618 | continue; |
| 619 | error = execute(batch[i], flags, args); |
| 620 | IRELE(batch[i]); |
| 621 | if (error == -EAGAIN) { |
| 622 | skipped++; |
| 623 | continue; |
| 624 | } |
| 625 | if (error && last_error != -EFSCORRUPTED) |
| 626 | last_error = error; |
| 627 | } |
| 628 | |
| 629 | /* bail out if the filesystem is corrupted. */ |
| 630 | if (error == -EFSCORRUPTED) |
| 631 | break; |
| 632 | |
| 633 | cond_resched(); |
| 634 | |
| 635 | } while (nr_found && !done); |
| 636 | |
| 637 | if (skipped) { |
| 638 | delay(1); |
| 639 | goto restart; |
| 640 | } |
| 641 | return last_error; |
| 642 | } |
| 643 | |
| 644 | /* |
| 645 | * Background scanning to trim post-EOF preallocated space. This is queued |
| 646 | * based on the 'speculative_prealloc_lifetime' tunable (5m by default). |
| 647 | */ |
| 648 | STATIC void |
| 649 | xfs_queue_eofblocks( |
| 650 | struct xfs_mount *mp) |
| 651 | { |
| 652 | rcu_read_lock(); |
| 653 | if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG)) |
| 654 | queue_delayed_work(mp->m_eofblocks_workqueue, |
| 655 | &mp->m_eofblocks_work, |
| 656 | msecs_to_jiffies(xfs_eofb_secs * 1000)); |
| 657 | rcu_read_unlock(); |
| 658 | } |
| 659 | |
| 660 | void |
| 661 | xfs_eofblocks_worker( |
| 662 | struct work_struct *work) |
| 663 | { |
| 664 | struct xfs_mount *mp = container_of(to_delayed_work(work), |
| 665 | struct xfs_mount, m_eofblocks_work); |
| 666 | xfs_icache_free_eofblocks(mp, NULL); |
| 667 | xfs_queue_eofblocks(mp); |
| 668 | } |
| 669 | |
| 670 | int |
| 671 | xfs_inode_ag_iterator( |
| 672 | struct xfs_mount *mp, |
| 673 | int (*execute)(struct xfs_inode *ip, int flags, |
| 674 | void *args), |
| 675 | int flags, |
| 676 | void *args) |
| 677 | { |
| 678 | struct xfs_perag *pag; |
| 679 | int error = 0; |
| 680 | int last_error = 0; |
| 681 | xfs_agnumber_t ag; |
| 682 | |
| 683 | ag = 0; |
| 684 | while ((pag = xfs_perag_get(mp, ag))) { |
| 685 | ag = pag->pag_agno + 1; |
| 686 | error = xfs_inode_ag_walk(mp, pag, execute, flags, args, -1); |
| 687 | xfs_perag_put(pag); |
| 688 | if (error) { |
| 689 | last_error = error; |
| 690 | if (error == -EFSCORRUPTED) |
| 691 | break; |
| 692 | } |
| 693 | } |
| 694 | return last_error; |
| 695 | } |
| 696 | |
| 697 | int |
| 698 | xfs_inode_ag_iterator_tag( |
| 699 | struct xfs_mount *mp, |
| 700 | int (*execute)(struct xfs_inode *ip, int flags, |
| 701 | void *args), |
| 702 | int flags, |
| 703 | void *args, |
| 704 | int tag) |
| 705 | { |
| 706 | struct xfs_perag *pag; |
| 707 | int error = 0; |
| 708 | int last_error = 0; |
| 709 | xfs_agnumber_t ag; |
| 710 | |
| 711 | ag = 0; |
| 712 | while ((pag = xfs_perag_get_tag(mp, ag, tag))) { |
| 713 | ag = pag->pag_agno + 1; |
| 714 | error = xfs_inode_ag_walk(mp, pag, execute, flags, args, tag); |
| 715 | xfs_perag_put(pag); |
| 716 | if (error) { |
| 717 | last_error = error; |
| 718 | if (error == -EFSCORRUPTED) |
| 719 | break; |
| 720 | } |
| 721 | } |
| 722 | return last_error; |
| 723 | } |
| 724 | |
| 725 | /* |
| 726 | * Queue a new inode reclaim pass if there are reclaimable inodes and there |
| 727 | * isn't a reclaim pass already in progress. By default it runs every 5s based |
| 728 | * on the xfs periodic sync default of 30s. Perhaps this should have it's own |
| 729 | * tunable, but that can be done if this method proves to be ineffective or too |
| 730 | * aggressive. |
| 731 | */ |
| 732 | static void |
| 733 | xfs_reclaim_work_queue( |
| 734 | struct xfs_mount *mp) |
| 735 | { |
| 736 | |
| 737 | rcu_read_lock(); |
| 738 | if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) { |
| 739 | queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work, |
| 740 | msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10)); |
| 741 | } |
| 742 | rcu_read_unlock(); |
| 743 | } |
| 744 | |
| 745 | /* |
| 746 | * This is a fast pass over the inode cache to try to get reclaim moving on as |
| 747 | * many inodes as possible in a short period of time. It kicks itself every few |
| 748 | * seconds, as well as being kicked by the inode cache shrinker when memory |
| 749 | * goes low. It scans as quickly as possible avoiding locked inodes or those |
| 750 | * already being flushed, and once done schedules a future pass. |
| 751 | */ |
| 752 | void |
| 753 | xfs_reclaim_worker( |
| 754 | struct work_struct *work) |
| 755 | { |
| 756 | struct xfs_mount *mp = container_of(to_delayed_work(work), |
| 757 | struct xfs_mount, m_reclaim_work); |
| 758 | |
| 759 | xfs_reclaim_inodes(mp, SYNC_TRYLOCK); |
| 760 | xfs_reclaim_work_queue(mp); |
| 761 | } |
| 762 | |
| 763 | static void |
| 764 | __xfs_inode_set_reclaim_tag( |
| 765 | struct xfs_perag *pag, |
| 766 | struct xfs_inode *ip) |
| 767 | { |
| 768 | radix_tree_tag_set(&pag->pag_ici_root, |
| 769 | XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), |
| 770 | XFS_ICI_RECLAIM_TAG); |
| 771 | |
| 772 | if (!pag->pag_ici_reclaimable) { |
| 773 | /* propagate the reclaim tag up into the perag radix tree */ |
| 774 | spin_lock(&ip->i_mount->m_perag_lock); |
| 775 | radix_tree_tag_set(&ip->i_mount->m_perag_tree, |
| 776 | XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino), |
| 777 | XFS_ICI_RECLAIM_TAG); |
| 778 | spin_unlock(&ip->i_mount->m_perag_lock); |
| 779 | |
| 780 | /* schedule periodic background inode reclaim */ |
| 781 | xfs_reclaim_work_queue(ip->i_mount); |
| 782 | |
| 783 | trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno, |
| 784 | -1, _RET_IP_); |
| 785 | } |
| 786 | pag->pag_ici_reclaimable++; |
| 787 | } |
| 788 | |
| 789 | /* |
| 790 | * We set the inode flag atomically with the radix tree tag. |
| 791 | * Once we get tag lookups on the radix tree, this inode flag |
| 792 | * can go away. |
| 793 | */ |
| 794 | void |
| 795 | xfs_inode_set_reclaim_tag( |
| 796 | xfs_inode_t *ip) |
| 797 | { |
| 798 | struct xfs_mount *mp = ip->i_mount; |
| 799 | struct xfs_perag *pag; |
| 800 | |
| 801 | pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); |
| 802 | spin_lock(&pag->pag_ici_lock); |
| 803 | spin_lock(&ip->i_flags_lock); |
| 804 | __xfs_inode_set_reclaim_tag(pag, ip); |
| 805 | __xfs_iflags_set(ip, XFS_IRECLAIMABLE); |
| 806 | spin_unlock(&ip->i_flags_lock); |
| 807 | spin_unlock(&pag->pag_ici_lock); |
| 808 | xfs_perag_put(pag); |
| 809 | } |
| 810 | |
| 811 | STATIC void |
| 812 | __xfs_inode_clear_reclaim( |
| 813 | xfs_perag_t *pag, |
| 814 | xfs_inode_t *ip) |
| 815 | { |
| 816 | pag->pag_ici_reclaimable--; |
| 817 | if (!pag->pag_ici_reclaimable) { |
| 818 | /* clear the reclaim tag from the perag radix tree */ |
| 819 | spin_lock(&ip->i_mount->m_perag_lock); |
| 820 | radix_tree_tag_clear(&ip->i_mount->m_perag_tree, |
| 821 | XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino), |
| 822 | XFS_ICI_RECLAIM_TAG); |
| 823 | spin_unlock(&ip->i_mount->m_perag_lock); |
| 824 | trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno, |
| 825 | -1, _RET_IP_); |
| 826 | } |
| 827 | } |
| 828 | |
| 829 | STATIC void |
| 830 | __xfs_inode_clear_reclaim_tag( |
| 831 | xfs_mount_t *mp, |
| 832 | xfs_perag_t *pag, |
| 833 | xfs_inode_t *ip) |
| 834 | { |
| 835 | radix_tree_tag_clear(&pag->pag_ici_root, |
| 836 | XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG); |
| 837 | __xfs_inode_clear_reclaim(pag, ip); |
| 838 | } |
| 839 | |
| 840 | /* |
| 841 | * Grab the inode for reclaim exclusively. |
| 842 | * Return 0 if we grabbed it, non-zero otherwise. |
| 843 | */ |
| 844 | STATIC int |
| 845 | xfs_reclaim_inode_grab( |
| 846 | struct xfs_inode *ip, |
| 847 | int flags) |
| 848 | { |
| 849 | ASSERT(rcu_read_lock_held()); |
| 850 | |
| 851 | /* quick check for stale RCU freed inode */ |
| 852 | if (!ip->i_ino) |
| 853 | return 1; |
| 854 | |
| 855 | /* |
| 856 | * If we are asked for non-blocking operation, do unlocked checks to |
| 857 | * see if the inode already is being flushed or in reclaim to avoid |
| 858 | * lock traffic. |
| 859 | */ |
| 860 | if ((flags & SYNC_TRYLOCK) && |
| 861 | __xfs_iflags_test(ip, XFS_IFLOCK | XFS_IRECLAIM)) |
| 862 | return 1; |
| 863 | |
| 864 | /* |
| 865 | * The radix tree lock here protects a thread in xfs_iget from racing |
| 866 | * with us starting reclaim on the inode. Once we have the |
| 867 | * XFS_IRECLAIM flag set it will not touch us. |
| 868 | * |
| 869 | * Due to RCU lookup, we may find inodes that have been freed and only |
| 870 | * have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that |
| 871 | * aren't candidates for reclaim at all, so we must check the |
| 872 | * XFS_IRECLAIMABLE is set first before proceeding to reclaim. |
| 873 | */ |
| 874 | spin_lock(&ip->i_flags_lock); |
| 875 | if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) || |
| 876 | __xfs_iflags_test(ip, XFS_IRECLAIM)) { |
| 877 | /* not a reclaim candidate. */ |
| 878 | spin_unlock(&ip->i_flags_lock); |
| 879 | return 1; |
| 880 | } |
| 881 | __xfs_iflags_set(ip, XFS_IRECLAIM); |
| 882 | spin_unlock(&ip->i_flags_lock); |
| 883 | return 0; |
| 884 | } |
| 885 | |
| 886 | /* |
| 887 | * Inodes in different states need to be treated differently. The following |
| 888 | * table lists the inode states and the reclaim actions necessary: |
| 889 | * |
| 890 | * inode state iflush ret required action |
| 891 | * --------------- ---------- --------------- |
| 892 | * bad - reclaim |
| 893 | * shutdown EIO unpin and reclaim |
| 894 | * clean, unpinned 0 reclaim |
| 895 | * stale, unpinned 0 reclaim |
| 896 | * clean, pinned(*) 0 requeue |
| 897 | * stale, pinned EAGAIN requeue |
| 898 | * dirty, async - requeue |
| 899 | * dirty, sync 0 reclaim |
| 900 | * |
| 901 | * (*) dgc: I don't think the clean, pinned state is possible but it gets |
| 902 | * handled anyway given the order of checks implemented. |
| 903 | * |
| 904 | * Also, because we get the flush lock first, we know that any inode that has |
| 905 | * been flushed delwri has had the flush completed by the time we check that |
| 906 | * the inode is clean. |
| 907 | * |
| 908 | * Note that because the inode is flushed delayed write by AIL pushing, the |
| 909 | * flush lock may already be held here and waiting on it can result in very |
| 910 | * long latencies. Hence for sync reclaims, where we wait on the flush lock, |
| 911 | * the caller should push the AIL first before trying to reclaim inodes to |
| 912 | * minimise the amount of time spent waiting. For background relaim, we only |
| 913 | * bother to reclaim clean inodes anyway. |
| 914 | * |
| 915 | * Hence the order of actions after gaining the locks should be: |
| 916 | * bad => reclaim |
| 917 | * shutdown => unpin and reclaim |
| 918 | * pinned, async => requeue |
| 919 | * pinned, sync => unpin |
| 920 | * stale => reclaim |
| 921 | * clean => reclaim |
| 922 | * dirty, async => requeue |
| 923 | * dirty, sync => flush, wait and reclaim |
| 924 | */ |
| 925 | STATIC int |
| 926 | xfs_reclaim_inode( |
| 927 | struct xfs_inode *ip, |
| 928 | struct xfs_perag *pag, |
| 929 | int sync_mode) |
| 930 | { |
| 931 | struct xfs_buf *bp = NULL; |
| 932 | int error; |
| 933 | |
| 934 | restart: |
| 935 | error = 0; |
| 936 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 937 | if (!xfs_iflock_nowait(ip)) { |
| 938 | if (!(sync_mode & SYNC_WAIT)) |
| 939 | goto out; |
| 940 | xfs_iflock(ip); |
| 941 | } |
| 942 | |
| 943 | if (XFS_FORCED_SHUTDOWN(ip->i_mount)) { |
| 944 | xfs_iunpin_wait(ip); |
| 945 | xfs_iflush_abort(ip, false); |
| 946 | goto reclaim; |
| 947 | } |
| 948 | if (xfs_ipincount(ip)) { |
| 949 | if (!(sync_mode & SYNC_WAIT)) |
| 950 | goto out_ifunlock; |
| 951 | xfs_iunpin_wait(ip); |
| 952 | } |
| 953 | if (xfs_iflags_test(ip, XFS_ISTALE)) |
| 954 | goto reclaim; |
| 955 | if (xfs_inode_clean(ip)) |
| 956 | goto reclaim; |
| 957 | |
| 958 | /* |
| 959 | * Never flush out dirty data during non-blocking reclaim, as it would |
| 960 | * just contend with AIL pushing trying to do the same job. |
| 961 | */ |
| 962 | if (!(sync_mode & SYNC_WAIT)) |
| 963 | goto out_ifunlock; |
| 964 | |
| 965 | /* |
| 966 | * Now we have an inode that needs flushing. |
| 967 | * |
| 968 | * Note that xfs_iflush will never block on the inode buffer lock, as |
| 969 | * xfs_ifree_cluster() can lock the inode buffer before it locks the |
| 970 | * ip->i_lock, and we are doing the exact opposite here. As a result, |
| 971 | * doing a blocking xfs_imap_to_bp() to get the cluster buffer would |
| 972 | * result in an ABBA deadlock with xfs_ifree_cluster(). |
| 973 | * |
| 974 | * As xfs_ifree_cluser() must gather all inodes that are active in the |
| 975 | * cache to mark them stale, if we hit this case we don't actually want |
| 976 | * to do IO here - we want the inode marked stale so we can simply |
| 977 | * reclaim it. Hence if we get an EAGAIN error here, just unlock the |
| 978 | * inode, back off and try again. Hopefully the next pass through will |
| 979 | * see the stale flag set on the inode. |
| 980 | */ |
| 981 | error = xfs_iflush(ip, &bp); |
| 982 | if (error == -EAGAIN) { |
| 983 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 984 | /* backoff longer than in xfs_ifree_cluster */ |
| 985 | delay(2); |
| 986 | goto restart; |
| 987 | } |
| 988 | |
| 989 | if (!error) { |
| 990 | error = xfs_bwrite(bp); |
| 991 | xfs_buf_relse(bp); |
| 992 | } |
| 993 | |
| 994 | xfs_iflock(ip); |
| 995 | reclaim: |
| 996 | xfs_ifunlock(ip); |
| 997 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 998 | |
| 999 | XFS_STATS_INC(ip->i_mount, xs_ig_reclaims); |
| 1000 | /* |
| 1001 | * Remove the inode from the per-AG radix tree. |
| 1002 | * |
| 1003 | * Because radix_tree_delete won't complain even if the item was never |
| 1004 | * added to the tree assert that it's been there before to catch |
| 1005 | * problems with the inode life time early on. |
| 1006 | */ |
| 1007 | spin_lock(&pag->pag_ici_lock); |
| 1008 | if (!radix_tree_delete(&pag->pag_ici_root, |
| 1009 | XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino))) |
| 1010 | ASSERT(0); |
| 1011 | __xfs_inode_clear_reclaim(pag, ip); |
| 1012 | spin_unlock(&pag->pag_ici_lock); |
| 1013 | |
| 1014 | /* |
| 1015 | * Here we do an (almost) spurious inode lock in order to coordinate |
| 1016 | * with inode cache radix tree lookups. This is because the lookup |
| 1017 | * can reference the inodes in the cache without taking references. |
| 1018 | * |
| 1019 | * We make that OK here by ensuring that we wait until the inode is |
| 1020 | * unlocked after the lookup before we go ahead and free it. |
| 1021 | */ |
| 1022 | xfs_ilock(ip, XFS_ILOCK_EXCL); |
| 1023 | xfs_qm_dqdetach(ip); |
| 1024 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 1025 | |
| 1026 | xfs_inode_free(ip); |
| 1027 | return error; |
| 1028 | |
| 1029 | out_ifunlock: |
| 1030 | xfs_ifunlock(ip); |
| 1031 | out: |
| 1032 | xfs_iflags_clear(ip, XFS_IRECLAIM); |
| 1033 | xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| 1034 | /* |
| 1035 | * We could return -EAGAIN here to make reclaim rescan the inode tree in |
| 1036 | * a short while. However, this just burns CPU time scanning the tree |
| 1037 | * waiting for IO to complete and the reclaim work never goes back to |
| 1038 | * the idle state. Instead, return 0 to let the next scheduled |
| 1039 | * background reclaim attempt to reclaim the inode again. |
| 1040 | */ |
| 1041 | return 0; |
| 1042 | } |
| 1043 | |
| 1044 | /* |
| 1045 | * Walk the AGs and reclaim the inodes in them. Even if the filesystem is |
| 1046 | * corrupted, we still want to try to reclaim all the inodes. If we don't, |
| 1047 | * then a shut down during filesystem unmount reclaim walk leak all the |
| 1048 | * unreclaimed inodes. |
| 1049 | */ |
| 1050 | STATIC int |
| 1051 | xfs_reclaim_inodes_ag( |
| 1052 | struct xfs_mount *mp, |
| 1053 | int flags, |
| 1054 | int *nr_to_scan) |
| 1055 | { |
| 1056 | struct xfs_perag *pag; |
| 1057 | int error = 0; |
| 1058 | int last_error = 0; |
| 1059 | xfs_agnumber_t ag; |
| 1060 | int trylock = flags & SYNC_TRYLOCK; |
| 1061 | int skipped; |
| 1062 | |
| 1063 | restart: |
| 1064 | ag = 0; |
| 1065 | skipped = 0; |
| 1066 | while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) { |
| 1067 | unsigned long first_index = 0; |
| 1068 | int done = 0; |
| 1069 | int nr_found = 0; |
| 1070 | |
| 1071 | ag = pag->pag_agno + 1; |
| 1072 | |
| 1073 | if (trylock) { |
| 1074 | if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) { |
| 1075 | skipped++; |
| 1076 | xfs_perag_put(pag); |
| 1077 | continue; |
| 1078 | } |
| 1079 | first_index = pag->pag_ici_reclaim_cursor; |
| 1080 | } else |
| 1081 | mutex_lock(&pag->pag_ici_reclaim_lock); |
| 1082 | |
| 1083 | do { |
| 1084 | struct xfs_inode *batch[XFS_LOOKUP_BATCH]; |
| 1085 | int i; |
| 1086 | |
| 1087 | rcu_read_lock(); |
| 1088 | nr_found = radix_tree_gang_lookup_tag( |
| 1089 | &pag->pag_ici_root, |
| 1090 | (void **)batch, first_index, |
| 1091 | XFS_LOOKUP_BATCH, |
| 1092 | XFS_ICI_RECLAIM_TAG); |
| 1093 | if (!nr_found) { |
| 1094 | done = 1; |
| 1095 | rcu_read_unlock(); |
| 1096 | break; |
| 1097 | } |
| 1098 | |
| 1099 | /* |
| 1100 | * Grab the inodes before we drop the lock. if we found |
| 1101 | * nothing, nr == 0 and the loop will be skipped. |
| 1102 | */ |
| 1103 | for (i = 0; i < nr_found; i++) { |
| 1104 | struct xfs_inode *ip = batch[i]; |
| 1105 | |
| 1106 | if (done || xfs_reclaim_inode_grab(ip, flags)) |
| 1107 | batch[i] = NULL; |
| 1108 | |
| 1109 | /* |
| 1110 | * Update the index for the next lookup. Catch |
| 1111 | * overflows into the next AG range which can |
| 1112 | * occur if we have inodes in the last block of |
| 1113 | * the AG and we are currently pointing to the |
| 1114 | * last inode. |
| 1115 | * |
| 1116 | * Because we may see inodes that are from the |
| 1117 | * wrong AG due to RCU freeing and |
| 1118 | * reallocation, only update the index if it |
| 1119 | * lies in this AG. It was a race that lead us |
| 1120 | * to see this inode, so another lookup from |
| 1121 | * the same index will not find it again. |
| 1122 | */ |
| 1123 | if (XFS_INO_TO_AGNO(mp, ip->i_ino) != |
| 1124 | pag->pag_agno) |
| 1125 | continue; |
| 1126 | first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1); |
| 1127 | if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) |
| 1128 | done = 1; |
| 1129 | } |
| 1130 | |
| 1131 | /* unlock now we've grabbed the inodes. */ |
| 1132 | rcu_read_unlock(); |
| 1133 | |
| 1134 | for (i = 0; i < nr_found; i++) { |
| 1135 | if (!batch[i]) |
| 1136 | continue; |
| 1137 | error = xfs_reclaim_inode(batch[i], pag, flags); |
| 1138 | if (error && last_error != -EFSCORRUPTED) |
| 1139 | last_error = error; |
| 1140 | } |
| 1141 | |
| 1142 | *nr_to_scan -= XFS_LOOKUP_BATCH; |
| 1143 | |
| 1144 | cond_resched(); |
| 1145 | |
| 1146 | } while (nr_found && !done && *nr_to_scan > 0); |
| 1147 | |
| 1148 | if (trylock && !done) |
| 1149 | pag->pag_ici_reclaim_cursor = first_index; |
| 1150 | else |
| 1151 | pag->pag_ici_reclaim_cursor = 0; |
| 1152 | mutex_unlock(&pag->pag_ici_reclaim_lock); |
| 1153 | xfs_perag_put(pag); |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * if we skipped any AG, and we still have scan count remaining, do |
| 1158 | * another pass this time using blocking reclaim semantics (i.e |
| 1159 | * waiting on the reclaim locks and ignoring the reclaim cursors). This |
| 1160 | * ensure that when we get more reclaimers than AGs we block rather |
| 1161 | * than spin trying to execute reclaim. |
| 1162 | */ |
| 1163 | if (skipped && (flags & SYNC_WAIT) && *nr_to_scan > 0) { |
| 1164 | trylock = 0; |
| 1165 | goto restart; |
| 1166 | } |
| 1167 | return last_error; |
| 1168 | } |
| 1169 | |
| 1170 | int |
| 1171 | xfs_reclaim_inodes( |
| 1172 | xfs_mount_t *mp, |
| 1173 | int mode) |
| 1174 | { |
| 1175 | int nr_to_scan = INT_MAX; |
| 1176 | |
| 1177 | return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan); |
| 1178 | } |
| 1179 | |
| 1180 | /* |
| 1181 | * Scan a certain number of inodes for reclaim. |
| 1182 | * |
| 1183 | * When called we make sure that there is a background (fast) inode reclaim in |
| 1184 | * progress, while we will throttle the speed of reclaim via doing synchronous |
| 1185 | * reclaim of inodes. That means if we come across dirty inodes, we wait for |
| 1186 | * them to be cleaned, which we hope will not be very long due to the |
| 1187 | * background walker having already kicked the IO off on those dirty inodes. |
| 1188 | */ |
| 1189 | long |
| 1190 | xfs_reclaim_inodes_nr( |
| 1191 | struct xfs_mount *mp, |
| 1192 | int nr_to_scan) |
| 1193 | { |
| 1194 | /* kick background reclaimer and push the AIL */ |
| 1195 | xfs_reclaim_work_queue(mp); |
| 1196 | xfs_ail_push_all(mp->m_ail); |
| 1197 | |
| 1198 | return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan); |
| 1199 | } |
| 1200 | |
| 1201 | /* |
| 1202 | * Return the number of reclaimable inodes in the filesystem for |
| 1203 | * the shrinker to determine how much to reclaim. |
| 1204 | */ |
| 1205 | int |
| 1206 | xfs_reclaim_inodes_count( |
| 1207 | struct xfs_mount *mp) |
| 1208 | { |
| 1209 | struct xfs_perag *pag; |
| 1210 | xfs_agnumber_t ag = 0; |
| 1211 | int reclaimable = 0; |
| 1212 | |
| 1213 | while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) { |
| 1214 | ag = pag->pag_agno + 1; |
| 1215 | reclaimable += pag->pag_ici_reclaimable; |
| 1216 | xfs_perag_put(pag); |
| 1217 | } |
| 1218 | return reclaimable; |
| 1219 | } |
| 1220 | |
| 1221 | STATIC int |
| 1222 | xfs_inode_match_id( |
| 1223 | struct xfs_inode *ip, |
| 1224 | struct xfs_eofblocks *eofb) |
| 1225 | { |
| 1226 | if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) && |
| 1227 | !uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid)) |
| 1228 | return 0; |
| 1229 | |
| 1230 | if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) && |
| 1231 | !gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid)) |
| 1232 | return 0; |
| 1233 | |
| 1234 | if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) && |
| 1235 | xfs_get_projid(ip) != eofb->eof_prid) |
| 1236 | return 0; |
| 1237 | |
| 1238 | return 1; |
| 1239 | } |
| 1240 | |
| 1241 | /* |
| 1242 | * A union-based inode filtering algorithm. Process the inode if any of the |
| 1243 | * criteria match. This is for global/internal scans only. |
| 1244 | */ |
| 1245 | STATIC int |
| 1246 | xfs_inode_match_id_union( |
| 1247 | struct xfs_inode *ip, |
| 1248 | struct xfs_eofblocks *eofb) |
| 1249 | { |
| 1250 | if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) && |
| 1251 | uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid)) |
| 1252 | return 1; |
| 1253 | |
| 1254 | if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) && |
| 1255 | gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid)) |
| 1256 | return 1; |
| 1257 | |
| 1258 | if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) && |
| 1259 | xfs_get_projid(ip) == eofb->eof_prid) |
| 1260 | return 1; |
| 1261 | |
| 1262 | return 0; |
| 1263 | } |
| 1264 | |
| 1265 | STATIC int |
| 1266 | xfs_inode_free_eofblocks( |
| 1267 | struct xfs_inode *ip, |
| 1268 | int flags, |
| 1269 | void *args) |
| 1270 | { |
| 1271 | int ret; |
| 1272 | struct xfs_eofblocks *eofb = args; |
| 1273 | bool need_iolock = true; |
| 1274 | int match; |
| 1275 | |
| 1276 | ASSERT(!eofb || (eofb && eofb->eof_scan_owner != 0)); |
| 1277 | |
| 1278 | if (!xfs_can_free_eofblocks(ip, false)) { |
| 1279 | /* inode could be preallocated or append-only */ |
| 1280 | trace_xfs_inode_free_eofblocks_invalid(ip); |
| 1281 | xfs_inode_clear_eofblocks_tag(ip); |
| 1282 | return 0; |
| 1283 | } |
| 1284 | |
| 1285 | /* |
| 1286 | * If the mapping is dirty the operation can block and wait for some |
| 1287 | * time. Unless we are waiting, skip it. |
| 1288 | */ |
| 1289 | if (!(flags & SYNC_WAIT) && |
| 1290 | mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY)) |
| 1291 | return 0; |
| 1292 | |
| 1293 | if (eofb) { |
| 1294 | if (eofb->eof_flags & XFS_EOF_FLAGS_UNION) |
| 1295 | match = xfs_inode_match_id_union(ip, eofb); |
| 1296 | else |
| 1297 | match = xfs_inode_match_id(ip, eofb); |
| 1298 | if (!match) |
| 1299 | return 0; |
| 1300 | |
| 1301 | /* skip the inode if the file size is too small */ |
| 1302 | if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE && |
| 1303 | XFS_ISIZE(ip) < eofb->eof_min_file_size) |
| 1304 | return 0; |
| 1305 | |
| 1306 | /* |
| 1307 | * A scan owner implies we already hold the iolock. Skip it in |
| 1308 | * xfs_free_eofblocks() to avoid deadlock. This also eliminates |
| 1309 | * the possibility of EAGAIN being returned. |
| 1310 | */ |
| 1311 | if (eofb->eof_scan_owner == ip->i_ino) |
| 1312 | need_iolock = false; |
| 1313 | } |
| 1314 | |
| 1315 | ret = xfs_free_eofblocks(ip->i_mount, ip, need_iolock); |
| 1316 | |
| 1317 | /* don't revisit the inode if we're not waiting */ |
| 1318 | if (ret == -EAGAIN && !(flags & SYNC_WAIT)) |
| 1319 | ret = 0; |
| 1320 | |
| 1321 | return ret; |
| 1322 | } |
| 1323 | |
| 1324 | int |
| 1325 | xfs_icache_free_eofblocks( |
| 1326 | struct xfs_mount *mp, |
| 1327 | struct xfs_eofblocks *eofb) |
| 1328 | { |
| 1329 | int flags = SYNC_TRYLOCK; |
| 1330 | |
| 1331 | if (eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC)) |
| 1332 | flags = SYNC_WAIT; |
| 1333 | |
| 1334 | return xfs_inode_ag_iterator_tag(mp, xfs_inode_free_eofblocks, flags, |
| 1335 | eofb, XFS_ICI_EOFBLOCKS_TAG); |
| 1336 | } |
| 1337 | |
| 1338 | /* |
| 1339 | * Run eofblocks scans on the quotas applicable to the inode. For inodes with |
| 1340 | * multiple quotas, we don't know exactly which quota caused an allocation |
| 1341 | * failure. We make a best effort by including each quota under low free space |
| 1342 | * conditions (less than 1% free space) in the scan. |
| 1343 | */ |
| 1344 | int |
| 1345 | xfs_inode_free_quota_eofblocks( |
| 1346 | struct xfs_inode *ip) |
| 1347 | { |
| 1348 | int scan = 0; |
| 1349 | struct xfs_eofblocks eofb = {0}; |
| 1350 | struct xfs_dquot *dq; |
| 1351 | |
| 1352 | ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); |
| 1353 | |
| 1354 | /* |
| 1355 | * Set the scan owner to avoid a potential livelock. Otherwise, the scan |
| 1356 | * can repeatedly trylock on the inode we're currently processing. We |
| 1357 | * run a sync scan to increase effectiveness and use the union filter to |
| 1358 | * cover all applicable quotas in a single scan. |
| 1359 | */ |
| 1360 | eofb.eof_scan_owner = ip->i_ino; |
| 1361 | eofb.eof_flags = XFS_EOF_FLAGS_UNION|XFS_EOF_FLAGS_SYNC; |
| 1362 | |
| 1363 | if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) { |
| 1364 | dq = xfs_inode_dquot(ip, XFS_DQ_USER); |
| 1365 | if (dq && xfs_dquot_lowsp(dq)) { |
| 1366 | eofb.eof_uid = VFS_I(ip)->i_uid; |
| 1367 | eofb.eof_flags |= XFS_EOF_FLAGS_UID; |
| 1368 | scan = 1; |
| 1369 | } |
| 1370 | } |
| 1371 | |
| 1372 | if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) { |
| 1373 | dq = xfs_inode_dquot(ip, XFS_DQ_GROUP); |
| 1374 | if (dq && xfs_dquot_lowsp(dq)) { |
| 1375 | eofb.eof_gid = VFS_I(ip)->i_gid; |
| 1376 | eofb.eof_flags |= XFS_EOF_FLAGS_GID; |
| 1377 | scan = 1; |
| 1378 | } |
| 1379 | } |
| 1380 | |
| 1381 | if (scan) |
| 1382 | xfs_icache_free_eofblocks(ip->i_mount, &eofb); |
| 1383 | |
| 1384 | return scan; |
| 1385 | } |
| 1386 | |
| 1387 | void |
| 1388 | xfs_inode_set_eofblocks_tag( |
| 1389 | xfs_inode_t *ip) |
| 1390 | { |
| 1391 | struct xfs_mount *mp = ip->i_mount; |
| 1392 | struct xfs_perag *pag; |
| 1393 | int tagged; |
| 1394 | |
| 1395 | pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); |
| 1396 | spin_lock(&pag->pag_ici_lock); |
| 1397 | trace_xfs_inode_set_eofblocks_tag(ip); |
| 1398 | |
| 1399 | tagged = radix_tree_tagged(&pag->pag_ici_root, |
| 1400 | XFS_ICI_EOFBLOCKS_TAG); |
| 1401 | radix_tree_tag_set(&pag->pag_ici_root, |
| 1402 | XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), |
| 1403 | XFS_ICI_EOFBLOCKS_TAG); |
| 1404 | if (!tagged) { |
| 1405 | /* propagate the eofblocks tag up into the perag radix tree */ |
| 1406 | spin_lock(&ip->i_mount->m_perag_lock); |
| 1407 | radix_tree_tag_set(&ip->i_mount->m_perag_tree, |
| 1408 | XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino), |
| 1409 | XFS_ICI_EOFBLOCKS_TAG); |
| 1410 | spin_unlock(&ip->i_mount->m_perag_lock); |
| 1411 | |
| 1412 | /* kick off background trimming */ |
| 1413 | xfs_queue_eofblocks(ip->i_mount); |
| 1414 | |
| 1415 | trace_xfs_perag_set_eofblocks(ip->i_mount, pag->pag_agno, |
| 1416 | -1, _RET_IP_); |
| 1417 | } |
| 1418 | |
| 1419 | spin_unlock(&pag->pag_ici_lock); |
| 1420 | xfs_perag_put(pag); |
| 1421 | } |
| 1422 | |
| 1423 | void |
| 1424 | xfs_inode_clear_eofblocks_tag( |
| 1425 | xfs_inode_t *ip) |
| 1426 | { |
| 1427 | struct xfs_mount *mp = ip->i_mount; |
| 1428 | struct xfs_perag *pag; |
| 1429 | |
| 1430 | pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino)); |
| 1431 | spin_lock(&pag->pag_ici_lock); |
| 1432 | trace_xfs_inode_clear_eofblocks_tag(ip); |
| 1433 | |
| 1434 | radix_tree_tag_clear(&pag->pag_ici_root, |
| 1435 | XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), |
| 1436 | XFS_ICI_EOFBLOCKS_TAG); |
| 1437 | if (!radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_EOFBLOCKS_TAG)) { |
| 1438 | /* clear the eofblocks tag from the perag radix tree */ |
| 1439 | spin_lock(&ip->i_mount->m_perag_lock); |
| 1440 | radix_tree_tag_clear(&ip->i_mount->m_perag_tree, |
| 1441 | XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino), |
| 1442 | XFS_ICI_EOFBLOCKS_TAG); |
| 1443 | spin_unlock(&ip->i_mount->m_perag_lock); |
| 1444 | trace_xfs_perag_clear_eofblocks(ip->i_mount, pag->pag_agno, |
| 1445 | -1, _RET_IP_); |
| 1446 | } |
| 1447 | |
| 1448 | spin_unlock(&pag->pag_ici_lock); |
| 1449 | xfs_perag_put(pag); |
| 1450 | } |
| 1451 | |