Loading...
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
40STATIC 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 */
46struct xfs_inode *
47xfs_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
90STATIC void
91xfs_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
100void
101xfs_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 */
148static int
149xfs_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 */
171static int
172xfs_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
297out_error:
298 spin_unlock(&ip->i_flags_lock);
299 rcu_read_unlock();
300 return error;
301}
302
303
304static int
305xfs_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
386out_preload_end:
387 spin_unlock(&pag->pag_ici_lock);
388 radix_tree_preload_end();
389 if (lock_flags)
390 xfs_iunlock(ip, lock_flags);
391out_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 */
419int
420xfs_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
452again:
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
482out_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
499STATIC int
500xfs_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
536out_unlock_noent:
537 spin_unlock(&ip->i_flags_lock);
538 return -ENOENT;
539}
540
541STATIC int
542xfs_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
557restart:
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 */
648STATIC void
649xfs_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
660void
661xfs_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
670int
671xfs_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
697int
698xfs_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 */
732static void
733xfs_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 */
752void
753xfs_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
763static 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 */
794void
795xfs_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
811STATIC 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
829STATIC 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 */
844STATIC int
845xfs_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 */
925STATIC int
926xfs_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
934restart:
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);
995reclaim:
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
1029out_ifunlock:
1030 xfs_ifunlock(ip);
1031out:
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 */
1050STATIC int
1051xfs_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
1063restart:
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
1170int
1171xfs_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 */
1189long
1190xfs_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 */
1205int
1206xfs_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
1221STATIC int
1222xfs_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 */
1245STATIC int
1246xfs_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
1265STATIC int
1266xfs_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
1324int
1325xfs_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 */
1344int
1345xfs_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
1387void
1388xfs_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
1423void
1424xfs_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
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#include "xfs_reflink.h"
37
38#include <linux/kthread.h>
39#include <linux/freezer.h>
40#include <linux/iversion.h>
41
42/*
43 * Allocate and initialise an xfs_inode.
44 */
45struct xfs_inode *
46xfs_inode_alloc(
47 struct xfs_mount *mp,
48 xfs_ino_t ino)
49{
50 struct xfs_inode *ip;
51
52 /*
53 * if this didn't occur in transactions, we could use
54 * KM_MAYFAIL and return NULL here on ENOMEM. Set the
55 * code up to do this anyway.
56 */
57 ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP);
58 if (!ip)
59 return NULL;
60 if (inode_init_always(mp->m_super, VFS_I(ip))) {
61 kmem_zone_free(xfs_inode_zone, ip);
62 return NULL;
63 }
64
65 /* VFS doesn't initialise i_mode! */
66 VFS_I(ip)->i_mode = 0;
67
68 XFS_STATS_INC(mp, vn_active);
69 ASSERT(atomic_read(&ip->i_pincount) == 0);
70 ASSERT(!xfs_isiflocked(ip));
71 ASSERT(ip->i_ino == 0);
72
73 /* initialise the xfs inode */
74 ip->i_ino = ino;
75 ip->i_mount = mp;
76 memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
77 ip->i_afp = NULL;
78 ip->i_cowfp = NULL;
79 ip->i_cnextents = 0;
80 ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
81 memset(&ip->i_df, 0, sizeof(xfs_ifork_t));
82 ip->i_flags = 0;
83 ip->i_delayed_blks = 0;
84 memset(&ip->i_d, 0, sizeof(ip->i_d));
85
86 return ip;
87}
88
89STATIC void
90xfs_inode_free_callback(
91 struct rcu_head *head)
92{
93 struct inode *inode = container_of(head, struct inode, i_rcu);
94 struct xfs_inode *ip = XFS_I(inode);
95
96 switch (VFS_I(ip)->i_mode & S_IFMT) {
97 case S_IFREG:
98 case S_IFDIR:
99 case S_IFLNK:
100 xfs_idestroy_fork(ip, XFS_DATA_FORK);
101 break;
102 }
103
104 if (ip->i_afp)
105 xfs_idestroy_fork(ip, XFS_ATTR_FORK);
106 if (ip->i_cowfp)
107 xfs_idestroy_fork(ip, XFS_COW_FORK);
108
109 if (ip->i_itemp) {
110 ASSERT(!(ip->i_itemp->ili_item.li_flags & XFS_LI_IN_AIL));
111 xfs_inode_item_destroy(ip);
112 ip->i_itemp = NULL;
113 }
114
115 kmem_zone_free(xfs_inode_zone, ip);
116}
117
118static void
119__xfs_inode_free(
120 struct xfs_inode *ip)
121{
122 /* asserts to verify all state is correct here */
123 ASSERT(atomic_read(&ip->i_pincount) == 0);
124 XFS_STATS_DEC(ip->i_mount, vn_active);
125
126 call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
127}
128
129void
130xfs_inode_free(
131 struct xfs_inode *ip)
132{
133 ASSERT(!xfs_isiflocked(ip));
134
135 /*
136 * Because we use RCU freeing we need to ensure the inode always
137 * appears to be reclaimed with an invalid inode number when in the
138 * free state. The ip->i_flags_lock provides the barrier against lookup
139 * races.
140 */
141 spin_lock(&ip->i_flags_lock);
142 ip->i_flags = XFS_IRECLAIM;
143 ip->i_ino = 0;
144 spin_unlock(&ip->i_flags_lock);
145
146 __xfs_inode_free(ip);
147}
148
149/*
150 * Queue a new inode reclaim pass if there are reclaimable inodes and there
151 * isn't a reclaim pass already in progress. By default it runs every 5s based
152 * on the xfs periodic sync default of 30s. Perhaps this should have it's own
153 * tunable, but that can be done if this method proves to be ineffective or too
154 * aggressive.
155 */
156static void
157xfs_reclaim_work_queue(
158 struct xfs_mount *mp)
159{
160
161 rcu_read_lock();
162 if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
163 queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work,
164 msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
165 }
166 rcu_read_unlock();
167}
168
169/*
170 * This is a fast pass over the inode cache to try to get reclaim moving on as
171 * many inodes as possible in a short period of time. It kicks itself every few
172 * seconds, as well as being kicked by the inode cache shrinker when memory
173 * goes low. It scans as quickly as possible avoiding locked inodes or those
174 * already being flushed, and once done schedules a future pass.
175 */
176void
177xfs_reclaim_worker(
178 struct work_struct *work)
179{
180 struct xfs_mount *mp = container_of(to_delayed_work(work),
181 struct xfs_mount, m_reclaim_work);
182
183 xfs_reclaim_inodes(mp, SYNC_TRYLOCK);
184 xfs_reclaim_work_queue(mp);
185}
186
187static void
188xfs_perag_set_reclaim_tag(
189 struct xfs_perag *pag)
190{
191 struct xfs_mount *mp = pag->pag_mount;
192
193 lockdep_assert_held(&pag->pag_ici_lock);
194 if (pag->pag_ici_reclaimable++)
195 return;
196
197 /* propagate the reclaim tag up into the perag radix tree */
198 spin_lock(&mp->m_perag_lock);
199 radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
200 XFS_ICI_RECLAIM_TAG);
201 spin_unlock(&mp->m_perag_lock);
202
203 /* schedule periodic background inode reclaim */
204 xfs_reclaim_work_queue(mp);
205
206 trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
207}
208
209static void
210xfs_perag_clear_reclaim_tag(
211 struct xfs_perag *pag)
212{
213 struct xfs_mount *mp = pag->pag_mount;
214
215 lockdep_assert_held(&pag->pag_ici_lock);
216 if (--pag->pag_ici_reclaimable)
217 return;
218
219 /* clear the reclaim tag from the perag radix tree */
220 spin_lock(&mp->m_perag_lock);
221 radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
222 XFS_ICI_RECLAIM_TAG);
223 spin_unlock(&mp->m_perag_lock);
224 trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
225}
226
227
228/*
229 * We set the inode flag atomically with the radix tree tag.
230 * Once we get tag lookups on the radix tree, this inode flag
231 * can go away.
232 */
233void
234xfs_inode_set_reclaim_tag(
235 struct xfs_inode *ip)
236{
237 struct xfs_mount *mp = ip->i_mount;
238 struct xfs_perag *pag;
239
240 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
241 spin_lock(&pag->pag_ici_lock);
242 spin_lock(&ip->i_flags_lock);
243
244 radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
245 XFS_ICI_RECLAIM_TAG);
246 xfs_perag_set_reclaim_tag(pag);
247 __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
248
249 spin_unlock(&ip->i_flags_lock);
250 spin_unlock(&pag->pag_ici_lock);
251 xfs_perag_put(pag);
252}
253
254STATIC void
255xfs_inode_clear_reclaim_tag(
256 struct xfs_perag *pag,
257 xfs_ino_t ino)
258{
259 radix_tree_tag_clear(&pag->pag_ici_root,
260 XFS_INO_TO_AGINO(pag->pag_mount, ino),
261 XFS_ICI_RECLAIM_TAG);
262 xfs_perag_clear_reclaim_tag(pag);
263}
264
265static void
266xfs_inew_wait(
267 struct xfs_inode *ip)
268{
269 wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_INEW_BIT);
270 DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_INEW_BIT);
271
272 do {
273 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
274 if (!xfs_iflags_test(ip, XFS_INEW))
275 break;
276 schedule();
277 } while (true);
278 finish_wait(wq, &wait.wq_entry);
279}
280
281/*
282 * When we recycle a reclaimable inode, we need to re-initialise the VFS inode
283 * part of the structure. This is made more complex by the fact we store
284 * information about the on-disk values in the VFS inode and so we can't just
285 * overwrite the values unconditionally. Hence we save the parameters we
286 * need to retain across reinitialisation, and rewrite them into the VFS inode
287 * after reinitialisation even if it fails.
288 */
289static int
290xfs_reinit_inode(
291 struct xfs_mount *mp,
292 struct inode *inode)
293{
294 int error;
295 uint32_t nlink = inode->i_nlink;
296 uint32_t generation = inode->i_generation;
297 uint64_t version = inode_peek_iversion(inode);
298 umode_t mode = inode->i_mode;
299 dev_t dev = inode->i_rdev;
300
301 error = inode_init_always(mp->m_super, inode);
302
303 set_nlink(inode, nlink);
304 inode->i_generation = generation;
305 inode_set_iversion_queried(inode, version);
306 inode->i_mode = mode;
307 inode->i_rdev = dev;
308 return error;
309}
310
311/*
312 * Check the validity of the inode we just found it the cache
313 */
314static int
315xfs_iget_cache_hit(
316 struct xfs_perag *pag,
317 struct xfs_inode *ip,
318 xfs_ino_t ino,
319 int flags,
320 int lock_flags) __releases(RCU)
321{
322 struct inode *inode = VFS_I(ip);
323 struct xfs_mount *mp = ip->i_mount;
324 int error;
325
326 /*
327 * check for re-use of an inode within an RCU grace period due to the
328 * radix tree nodes not being updated yet. We monitor for this by
329 * setting the inode number to zero before freeing the inode structure.
330 * If the inode has been reallocated and set up, then the inode number
331 * will not match, so check for that, too.
332 */
333 spin_lock(&ip->i_flags_lock);
334 if (ip->i_ino != ino) {
335 trace_xfs_iget_skip(ip);
336 XFS_STATS_INC(mp, xs_ig_frecycle);
337 error = -EAGAIN;
338 goto out_error;
339 }
340
341
342 /*
343 * If we are racing with another cache hit that is currently
344 * instantiating this inode or currently recycling it out of
345 * reclaimabe state, wait for the initialisation to complete
346 * before continuing.
347 *
348 * XXX(hch): eventually we should do something equivalent to
349 * wait_on_inode to wait for these flags to be cleared
350 * instead of polling for it.
351 */
352 if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
353 trace_xfs_iget_skip(ip);
354 XFS_STATS_INC(mp, xs_ig_frecycle);
355 error = -EAGAIN;
356 goto out_error;
357 }
358
359 /*
360 * If lookup is racing with unlink return an error immediately.
361 */
362 if (VFS_I(ip)->i_mode == 0 && !(flags & XFS_IGET_CREATE)) {
363 error = -ENOENT;
364 goto out_error;
365 }
366
367 /*
368 * If IRECLAIMABLE is set, we've torn down the VFS inode already.
369 * Need to carefully get it back into useable state.
370 */
371 if (ip->i_flags & XFS_IRECLAIMABLE) {
372 trace_xfs_iget_reclaim(ip);
373
374 if (flags & XFS_IGET_INCORE) {
375 error = -EAGAIN;
376 goto out_error;
377 }
378
379 /*
380 * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
381 * from stomping over us while we recycle the inode. We can't
382 * clear the radix tree reclaimable tag yet as it requires
383 * pag_ici_lock to be held exclusive.
384 */
385 ip->i_flags |= XFS_IRECLAIM;
386
387 spin_unlock(&ip->i_flags_lock);
388 rcu_read_unlock();
389
390 error = xfs_reinit_inode(mp, inode);
391 if (error) {
392 bool wake;
393 /*
394 * Re-initializing the inode failed, and we are in deep
395 * trouble. Try to re-add it to the reclaim list.
396 */
397 rcu_read_lock();
398 spin_lock(&ip->i_flags_lock);
399 wake = !!__xfs_iflags_test(ip, XFS_INEW);
400 ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
401 if (wake)
402 wake_up_bit(&ip->i_flags, __XFS_INEW_BIT);
403 ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
404 trace_xfs_iget_reclaim_fail(ip);
405 goto out_error;
406 }
407
408 spin_lock(&pag->pag_ici_lock);
409 spin_lock(&ip->i_flags_lock);
410
411 /*
412 * Clear the per-lifetime state in the inode as we are now
413 * effectively a new inode and need to return to the initial
414 * state before reuse occurs.
415 */
416 ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
417 ip->i_flags |= XFS_INEW;
418 xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
419 inode->i_state = I_NEW;
420
421 ASSERT(!rwsem_is_locked(&inode->i_rwsem));
422 init_rwsem(&inode->i_rwsem);
423
424 spin_unlock(&ip->i_flags_lock);
425 spin_unlock(&pag->pag_ici_lock);
426 } else {
427 /* If the VFS inode is being torn down, pause and try again. */
428 if (!igrab(inode)) {
429 trace_xfs_iget_skip(ip);
430 error = -EAGAIN;
431 goto out_error;
432 }
433
434 /* We've got a live one. */
435 spin_unlock(&ip->i_flags_lock);
436 rcu_read_unlock();
437 trace_xfs_iget_hit(ip);
438 }
439
440 if (lock_flags != 0)
441 xfs_ilock(ip, lock_flags);
442
443 if (!(flags & XFS_IGET_INCORE))
444 xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE);
445 XFS_STATS_INC(mp, xs_ig_found);
446
447 return 0;
448
449out_error:
450 spin_unlock(&ip->i_flags_lock);
451 rcu_read_unlock();
452 return error;
453}
454
455
456static int
457xfs_iget_cache_miss(
458 struct xfs_mount *mp,
459 struct xfs_perag *pag,
460 xfs_trans_t *tp,
461 xfs_ino_t ino,
462 struct xfs_inode **ipp,
463 int flags,
464 int lock_flags)
465{
466 struct xfs_inode *ip;
467 int error;
468 xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
469 int iflags;
470
471 ip = xfs_inode_alloc(mp, ino);
472 if (!ip)
473 return -ENOMEM;
474
475 error = xfs_iread(mp, tp, ip, flags);
476 if (error)
477 goto out_destroy;
478
479 if (!xfs_inode_verify_forks(ip)) {
480 error = -EFSCORRUPTED;
481 goto out_destroy;
482 }
483
484 trace_xfs_iget_miss(ip);
485
486
487 /*
488 * If we are allocating a new inode, then check what was returned is
489 * actually a free, empty inode. If we are not allocating an inode,
490 * the check we didn't find a free inode.
491 */
492 if (flags & XFS_IGET_CREATE) {
493 if (VFS_I(ip)->i_mode != 0) {
494 xfs_warn(mp,
495"Corruption detected! Free inode 0x%llx not marked free on disk",
496 ino);
497 error = -EFSCORRUPTED;
498 goto out_destroy;
499 }
500 if (ip->i_d.di_nblocks != 0) {
501 xfs_warn(mp,
502"Corruption detected! Free inode 0x%llx has blocks allocated!",
503 ino);
504 error = -EFSCORRUPTED;
505 goto out_destroy;
506 }
507 } else if (VFS_I(ip)->i_mode == 0) {
508 error = -ENOENT;
509 goto out_destroy;
510 }
511
512 /*
513 * Preload the radix tree so we can insert safely under the
514 * write spinlock. Note that we cannot sleep inside the preload
515 * region. Since we can be called from transaction context, don't
516 * recurse into the file system.
517 */
518 if (radix_tree_preload(GFP_NOFS)) {
519 error = -EAGAIN;
520 goto out_destroy;
521 }
522
523 /*
524 * Because the inode hasn't been added to the radix-tree yet it can't
525 * be found by another thread, so we can do the non-sleeping lock here.
526 */
527 if (lock_flags) {
528 if (!xfs_ilock_nowait(ip, lock_flags))
529 BUG();
530 }
531
532 /*
533 * These values must be set before inserting the inode into the radix
534 * tree as the moment it is inserted a concurrent lookup (allowed by the
535 * RCU locking mechanism) can find it and that lookup must see that this
536 * is an inode currently under construction (i.e. that XFS_INEW is set).
537 * The ip->i_flags_lock that protects the XFS_INEW flag forms the
538 * memory barrier that ensures this detection works correctly at lookup
539 * time.
540 */
541 iflags = XFS_INEW;
542 if (flags & XFS_IGET_DONTCACHE)
543 iflags |= XFS_IDONTCACHE;
544 ip->i_udquot = NULL;
545 ip->i_gdquot = NULL;
546 ip->i_pdquot = NULL;
547 xfs_iflags_set(ip, iflags);
548
549 /* insert the new inode */
550 spin_lock(&pag->pag_ici_lock);
551 error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
552 if (unlikely(error)) {
553 WARN_ON(error != -EEXIST);
554 XFS_STATS_INC(mp, xs_ig_dup);
555 error = -EAGAIN;
556 goto out_preload_end;
557 }
558 spin_unlock(&pag->pag_ici_lock);
559 radix_tree_preload_end();
560
561 *ipp = ip;
562 return 0;
563
564out_preload_end:
565 spin_unlock(&pag->pag_ici_lock);
566 radix_tree_preload_end();
567 if (lock_flags)
568 xfs_iunlock(ip, lock_flags);
569out_destroy:
570 __destroy_inode(VFS_I(ip));
571 xfs_inode_free(ip);
572 return error;
573}
574
575/*
576 * Look up an inode by number in the given file system.
577 * The inode is looked up in the cache held in each AG.
578 * If the inode is found in the cache, initialise the vfs inode
579 * if necessary.
580 *
581 * If it is not in core, read it in from the file system's device,
582 * add it to the cache and initialise the vfs inode.
583 *
584 * The inode is locked according to the value of the lock_flags parameter.
585 * This flag parameter indicates how and if the inode's IO lock and inode lock
586 * should be taken.
587 *
588 * mp -- the mount point structure for the current file system. It points
589 * to the inode hash table.
590 * tp -- a pointer to the current transaction if there is one. This is
591 * simply passed through to the xfs_iread() call.
592 * ino -- the number of the inode desired. This is the unique identifier
593 * within the file system for the inode being requested.
594 * lock_flags -- flags indicating how to lock the inode. See the comment
595 * for xfs_ilock() for a list of valid values.
596 */
597int
598xfs_iget(
599 xfs_mount_t *mp,
600 xfs_trans_t *tp,
601 xfs_ino_t ino,
602 uint flags,
603 uint lock_flags,
604 xfs_inode_t **ipp)
605{
606 xfs_inode_t *ip;
607 int error;
608 xfs_perag_t *pag;
609 xfs_agino_t agino;
610
611 /*
612 * xfs_reclaim_inode() uses the ILOCK to ensure an inode
613 * doesn't get freed while it's being referenced during a
614 * radix tree traversal here. It assumes this function
615 * aqcuires only the ILOCK (and therefore it has no need to
616 * involve the IOLOCK in this synchronization).
617 */
618 ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
619
620 /* reject inode numbers outside existing AGs */
621 if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
622 return -EINVAL;
623
624 XFS_STATS_INC(mp, xs_ig_attempts);
625
626 /* get the perag structure and ensure that it's inode capable */
627 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
628 agino = XFS_INO_TO_AGINO(mp, ino);
629
630again:
631 error = 0;
632 rcu_read_lock();
633 ip = radix_tree_lookup(&pag->pag_ici_root, agino);
634
635 if (ip) {
636 error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
637 if (error)
638 goto out_error_or_again;
639 } else {
640 rcu_read_unlock();
641 if (flags & XFS_IGET_INCORE) {
642 error = -ENODATA;
643 goto out_error_or_again;
644 }
645 XFS_STATS_INC(mp, xs_ig_missed);
646
647 error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
648 flags, lock_flags);
649 if (error)
650 goto out_error_or_again;
651 }
652 xfs_perag_put(pag);
653
654 *ipp = ip;
655
656 /*
657 * If we have a real type for an on-disk inode, we can setup the inode
658 * now. If it's a new inode being created, xfs_ialloc will handle it.
659 */
660 if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0)
661 xfs_setup_existing_inode(ip);
662 return 0;
663
664out_error_or_again:
665 if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) {
666 delay(1);
667 goto again;
668 }
669 xfs_perag_put(pag);
670 return error;
671}
672
673/*
674 * "Is this a cached inode that's also allocated?"
675 *
676 * Look up an inode by number in the given file system. If the inode is
677 * in cache and isn't in purgatory, return 1 if the inode is allocated
678 * and 0 if it is not. For all other cases (not in cache, being torn
679 * down, etc.), return a negative error code.
680 *
681 * The caller has to prevent inode allocation and freeing activity,
682 * presumably by locking the AGI buffer. This is to ensure that an
683 * inode cannot transition from allocated to freed until the caller is
684 * ready to allow that. If the inode is in an intermediate state (new,
685 * reclaimable, or being reclaimed), -EAGAIN will be returned; if the
686 * inode is not in the cache, -ENOENT will be returned. The caller must
687 * deal with these scenarios appropriately.
688 *
689 * This is a specialized use case for the online scrubber; if you're
690 * reading this, you probably want xfs_iget.
691 */
692int
693xfs_icache_inode_is_allocated(
694 struct xfs_mount *mp,
695 struct xfs_trans *tp,
696 xfs_ino_t ino,
697 bool *inuse)
698{
699 struct xfs_inode *ip;
700 int error;
701
702 error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip);
703 if (error)
704 return error;
705
706 *inuse = !!(VFS_I(ip)->i_mode);
707 IRELE(ip);
708 return 0;
709}
710
711/*
712 * The inode lookup is done in batches to keep the amount of lock traffic and
713 * radix tree lookups to a minimum. The batch size is a trade off between
714 * lookup reduction and stack usage. This is in the reclaim path, so we can't
715 * be too greedy.
716 */
717#define XFS_LOOKUP_BATCH 32
718
719STATIC int
720xfs_inode_ag_walk_grab(
721 struct xfs_inode *ip,
722 int flags)
723{
724 struct inode *inode = VFS_I(ip);
725 bool newinos = !!(flags & XFS_AGITER_INEW_WAIT);
726
727 ASSERT(rcu_read_lock_held());
728
729 /*
730 * check for stale RCU freed inode
731 *
732 * If the inode has been reallocated, it doesn't matter if it's not in
733 * the AG we are walking - we are walking for writeback, so if it
734 * passes all the "valid inode" checks and is dirty, then we'll write
735 * it back anyway. If it has been reallocated and still being
736 * initialised, the XFS_INEW check below will catch it.
737 */
738 spin_lock(&ip->i_flags_lock);
739 if (!ip->i_ino)
740 goto out_unlock_noent;
741
742 /* avoid new or reclaimable inodes. Leave for reclaim code to flush */
743 if ((!newinos && __xfs_iflags_test(ip, XFS_INEW)) ||
744 __xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM))
745 goto out_unlock_noent;
746 spin_unlock(&ip->i_flags_lock);
747
748 /* nothing to sync during shutdown */
749 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
750 return -EFSCORRUPTED;
751
752 /* If we can't grab the inode, it must on it's way to reclaim. */
753 if (!igrab(inode))
754 return -ENOENT;
755
756 /* inode is valid */
757 return 0;
758
759out_unlock_noent:
760 spin_unlock(&ip->i_flags_lock);
761 return -ENOENT;
762}
763
764STATIC int
765xfs_inode_ag_walk(
766 struct xfs_mount *mp,
767 struct xfs_perag *pag,
768 int (*execute)(struct xfs_inode *ip, int flags,
769 void *args),
770 int flags,
771 void *args,
772 int tag,
773 int iter_flags)
774{
775 uint32_t first_index;
776 int last_error = 0;
777 int skipped;
778 int done;
779 int nr_found;
780
781restart:
782 done = 0;
783 skipped = 0;
784 first_index = 0;
785 nr_found = 0;
786 do {
787 struct xfs_inode *batch[XFS_LOOKUP_BATCH];
788 int error = 0;
789 int i;
790
791 rcu_read_lock();
792
793 if (tag == -1)
794 nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
795 (void **)batch, first_index,
796 XFS_LOOKUP_BATCH);
797 else
798 nr_found = radix_tree_gang_lookup_tag(
799 &pag->pag_ici_root,
800 (void **) batch, first_index,
801 XFS_LOOKUP_BATCH, tag);
802
803 if (!nr_found) {
804 rcu_read_unlock();
805 break;
806 }
807
808 /*
809 * Grab the inodes before we drop the lock. if we found
810 * nothing, nr == 0 and the loop will be skipped.
811 */
812 for (i = 0; i < nr_found; i++) {
813 struct xfs_inode *ip = batch[i];
814
815 if (done || xfs_inode_ag_walk_grab(ip, iter_flags))
816 batch[i] = NULL;
817
818 /*
819 * Update the index for the next lookup. Catch
820 * overflows into the next AG range which can occur if
821 * we have inodes in the last block of the AG and we
822 * are currently pointing to the last inode.
823 *
824 * Because we may see inodes that are from the wrong AG
825 * due to RCU freeing and reallocation, only update the
826 * index if it lies in this AG. It was a race that lead
827 * us to see this inode, so another lookup from the
828 * same index will not find it again.
829 */
830 if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
831 continue;
832 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
833 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
834 done = 1;
835 }
836
837 /* unlock now we've grabbed the inodes. */
838 rcu_read_unlock();
839
840 for (i = 0; i < nr_found; i++) {
841 if (!batch[i])
842 continue;
843 if ((iter_flags & XFS_AGITER_INEW_WAIT) &&
844 xfs_iflags_test(batch[i], XFS_INEW))
845 xfs_inew_wait(batch[i]);
846 error = execute(batch[i], flags, args);
847 IRELE(batch[i]);
848 if (error == -EAGAIN) {
849 skipped++;
850 continue;
851 }
852 if (error && last_error != -EFSCORRUPTED)
853 last_error = error;
854 }
855
856 /* bail out if the filesystem is corrupted. */
857 if (error == -EFSCORRUPTED)
858 break;
859
860 cond_resched();
861
862 } while (nr_found && !done);
863
864 if (skipped) {
865 delay(1);
866 goto restart;
867 }
868 return last_error;
869}
870
871/*
872 * Background scanning to trim post-EOF preallocated space. This is queued
873 * based on the 'speculative_prealloc_lifetime' tunable (5m by default).
874 */
875void
876xfs_queue_eofblocks(
877 struct xfs_mount *mp)
878{
879 rcu_read_lock();
880 if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG))
881 queue_delayed_work(mp->m_eofblocks_workqueue,
882 &mp->m_eofblocks_work,
883 msecs_to_jiffies(xfs_eofb_secs * 1000));
884 rcu_read_unlock();
885}
886
887void
888xfs_eofblocks_worker(
889 struct work_struct *work)
890{
891 struct xfs_mount *mp = container_of(to_delayed_work(work),
892 struct xfs_mount, m_eofblocks_work);
893 xfs_icache_free_eofblocks(mp, NULL);
894 xfs_queue_eofblocks(mp);
895}
896
897/*
898 * Background scanning to trim preallocated CoW space. This is queued
899 * based on the 'speculative_cow_prealloc_lifetime' tunable (5m by default).
900 * (We'll just piggyback on the post-EOF prealloc space workqueue.)
901 */
902void
903xfs_queue_cowblocks(
904 struct xfs_mount *mp)
905{
906 rcu_read_lock();
907 if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_COWBLOCKS_TAG))
908 queue_delayed_work(mp->m_eofblocks_workqueue,
909 &mp->m_cowblocks_work,
910 msecs_to_jiffies(xfs_cowb_secs * 1000));
911 rcu_read_unlock();
912}
913
914void
915xfs_cowblocks_worker(
916 struct work_struct *work)
917{
918 struct xfs_mount *mp = container_of(to_delayed_work(work),
919 struct xfs_mount, m_cowblocks_work);
920 xfs_icache_free_cowblocks(mp, NULL);
921 xfs_queue_cowblocks(mp);
922}
923
924int
925xfs_inode_ag_iterator_flags(
926 struct xfs_mount *mp,
927 int (*execute)(struct xfs_inode *ip, int flags,
928 void *args),
929 int flags,
930 void *args,
931 int iter_flags)
932{
933 struct xfs_perag *pag;
934 int error = 0;
935 int last_error = 0;
936 xfs_agnumber_t ag;
937
938 ag = 0;
939 while ((pag = xfs_perag_get(mp, ag))) {
940 ag = pag->pag_agno + 1;
941 error = xfs_inode_ag_walk(mp, pag, execute, flags, args, -1,
942 iter_flags);
943 xfs_perag_put(pag);
944 if (error) {
945 last_error = error;
946 if (error == -EFSCORRUPTED)
947 break;
948 }
949 }
950 return last_error;
951}
952
953int
954xfs_inode_ag_iterator(
955 struct xfs_mount *mp,
956 int (*execute)(struct xfs_inode *ip, int flags,
957 void *args),
958 int flags,
959 void *args)
960{
961 return xfs_inode_ag_iterator_flags(mp, execute, flags, args, 0);
962}
963
964int
965xfs_inode_ag_iterator_tag(
966 struct xfs_mount *mp,
967 int (*execute)(struct xfs_inode *ip, int flags,
968 void *args),
969 int flags,
970 void *args,
971 int tag)
972{
973 struct xfs_perag *pag;
974 int error = 0;
975 int last_error = 0;
976 xfs_agnumber_t ag;
977
978 ag = 0;
979 while ((pag = xfs_perag_get_tag(mp, ag, tag))) {
980 ag = pag->pag_agno + 1;
981 error = xfs_inode_ag_walk(mp, pag, execute, flags, args, tag,
982 0);
983 xfs_perag_put(pag);
984 if (error) {
985 last_error = error;
986 if (error == -EFSCORRUPTED)
987 break;
988 }
989 }
990 return last_error;
991}
992
993/*
994 * Grab the inode for reclaim exclusively.
995 * Return 0 if we grabbed it, non-zero otherwise.
996 */
997STATIC int
998xfs_reclaim_inode_grab(
999 struct xfs_inode *ip,
1000 int flags)
1001{
1002 ASSERT(rcu_read_lock_held());
1003
1004 /* quick check for stale RCU freed inode */
1005 if (!ip->i_ino)
1006 return 1;
1007
1008 /*
1009 * If we are asked for non-blocking operation, do unlocked checks to
1010 * see if the inode already is being flushed or in reclaim to avoid
1011 * lock traffic.
1012 */
1013 if ((flags & SYNC_TRYLOCK) &&
1014 __xfs_iflags_test(ip, XFS_IFLOCK | XFS_IRECLAIM))
1015 return 1;
1016
1017 /*
1018 * The radix tree lock here protects a thread in xfs_iget from racing
1019 * with us starting reclaim on the inode. Once we have the
1020 * XFS_IRECLAIM flag set it will not touch us.
1021 *
1022 * Due to RCU lookup, we may find inodes that have been freed and only
1023 * have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that
1024 * aren't candidates for reclaim at all, so we must check the
1025 * XFS_IRECLAIMABLE is set first before proceeding to reclaim.
1026 */
1027 spin_lock(&ip->i_flags_lock);
1028 if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
1029 __xfs_iflags_test(ip, XFS_IRECLAIM)) {
1030 /* not a reclaim candidate. */
1031 spin_unlock(&ip->i_flags_lock);
1032 return 1;
1033 }
1034 __xfs_iflags_set(ip, XFS_IRECLAIM);
1035 spin_unlock(&ip->i_flags_lock);
1036 return 0;
1037}
1038
1039/*
1040 * Inodes in different states need to be treated differently. The following
1041 * table lists the inode states and the reclaim actions necessary:
1042 *
1043 * inode state iflush ret required action
1044 * --------------- ---------- ---------------
1045 * bad - reclaim
1046 * shutdown EIO unpin and reclaim
1047 * clean, unpinned 0 reclaim
1048 * stale, unpinned 0 reclaim
1049 * clean, pinned(*) 0 requeue
1050 * stale, pinned EAGAIN requeue
1051 * dirty, async - requeue
1052 * dirty, sync 0 reclaim
1053 *
1054 * (*) dgc: I don't think the clean, pinned state is possible but it gets
1055 * handled anyway given the order of checks implemented.
1056 *
1057 * Also, because we get the flush lock first, we know that any inode that has
1058 * been flushed delwri has had the flush completed by the time we check that
1059 * the inode is clean.
1060 *
1061 * Note that because the inode is flushed delayed write by AIL pushing, the
1062 * flush lock may already be held here and waiting on it can result in very
1063 * long latencies. Hence for sync reclaims, where we wait on the flush lock,
1064 * the caller should push the AIL first before trying to reclaim inodes to
1065 * minimise the amount of time spent waiting. For background relaim, we only
1066 * bother to reclaim clean inodes anyway.
1067 *
1068 * Hence the order of actions after gaining the locks should be:
1069 * bad => reclaim
1070 * shutdown => unpin and reclaim
1071 * pinned, async => requeue
1072 * pinned, sync => unpin
1073 * stale => reclaim
1074 * clean => reclaim
1075 * dirty, async => requeue
1076 * dirty, sync => flush, wait and reclaim
1077 */
1078STATIC int
1079xfs_reclaim_inode(
1080 struct xfs_inode *ip,
1081 struct xfs_perag *pag,
1082 int sync_mode)
1083{
1084 struct xfs_buf *bp = NULL;
1085 xfs_ino_t ino = ip->i_ino; /* for radix_tree_delete */
1086 int error;
1087
1088restart:
1089 error = 0;
1090 xfs_ilock(ip, XFS_ILOCK_EXCL);
1091 if (!xfs_iflock_nowait(ip)) {
1092 if (!(sync_mode & SYNC_WAIT))
1093 goto out;
1094 xfs_iflock(ip);
1095 }
1096
1097 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
1098 xfs_iunpin_wait(ip);
1099 /* xfs_iflush_abort() drops the flush lock */
1100 xfs_iflush_abort(ip, false);
1101 goto reclaim;
1102 }
1103 if (xfs_ipincount(ip)) {
1104 if (!(sync_mode & SYNC_WAIT))
1105 goto out_ifunlock;
1106 xfs_iunpin_wait(ip);
1107 }
1108 if (xfs_iflags_test(ip, XFS_ISTALE) || xfs_inode_clean(ip)) {
1109 xfs_ifunlock(ip);
1110 goto reclaim;
1111 }
1112
1113 /*
1114 * Never flush out dirty data during non-blocking reclaim, as it would
1115 * just contend with AIL pushing trying to do the same job.
1116 */
1117 if (!(sync_mode & SYNC_WAIT))
1118 goto out_ifunlock;
1119
1120 /*
1121 * Now we have an inode that needs flushing.
1122 *
1123 * Note that xfs_iflush will never block on the inode buffer lock, as
1124 * xfs_ifree_cluster() can lock the inode buffer before it locks the
1125 * ip->i_lock, and we are doing the exact opposite here. As a result,
1126 * doing a blocking xfs_imap_to_bp() to get the cluster buffer would
1127 * result in an ABBA deadlock with xfs_ifree_cluster().
1128 *
1129 * As xfs_ifree_cluser() must gather all inodes that are active in the
1130 * cache to mark them stale, if we hit this case we don't actually want
1131 * to do IO here - we want the inode marked stale so we can simply
1132 * reclaim it. Hence if we get an EAGAIN error here, just unlock the
1133 * inode, back off and try again. Hopefully the next pass through will
1134 * see the stale flag set on the inode.
1135 */
1136 error = xfs_iflush(ip, &bp);
1137 if (error == -EAGAIN) {
1138 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1139 /* backoff longer than in xfs_ifree_cluster */
1140 delay(2);
1141 goto restart;
1142 }
1143
1144 if (!error) {
1145 error = xfs_bwrite(bp);
1146 xfs_buf_relse(bp);
1147 }
1148
1149reclaim:
1150 ASSERT(!xfs_isiflocked(ip));
1151
1152 /*
1153 * Because we use RCU freeing we need to ensure the inode always appears
1154 * to be reclaimed with an invalid inode number when in the free state.
1155 * We do this as early as possible under the ILOCK so that
1156 * xfs_iflush_cluster() and xfs_ifree_cluster() can be guaranteed to
1157 * detect races with us here. By doing this, we guarantee that once
1158 * xfs_iflush_cluster() or xfs_ifree_cluster() has locked XFS_ILOCK that
1159 * it will see either a valid inode that will serialise correctly, or it
1160 * will see an invalid inode that it can skip.
1161 */
1162 spin_lock(&ip->i_flags_lock);
1163 ip->i_flags = XFS_IRECLAIM;
1164 ip->i_ino = 0;
1165 spin_unlock(&ip->i_flags_lock);
1166
1167 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1168
1169 XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
1170 /*
1171 * Remove the inode from the per-AG radix tree.
1172 *
1173 * Because radix_tree_delete won't complain even if the item was never
1174 * added to the tree assert that it's been there before to catch
1175 * problems with the inode life time early on.
1176 */
1177 spin_lock(&pag->pag_ici_lock);
1178 if (!radix_tree_delete(&pag->pag_ici_root,
1179 XFS_INO_TO_AGINO(ip->i_mount, ino)))
1180 ASSERT(0);
1181 xfs_perag_clear_reclaim_tag(pag);
1182 spin_unlock(&pag->pag_ici_lock);
1183
1184 /*
1185 * Here we do an (almost) spurious inode lock in order to coordinate
1186 * with inode cache radix tree lookups. This is because the lookup
1187 * can reference the inodes in the cache without taking references.
1188 *
1189 * We make that OK here by ensuring that we wait until the inode is
1190 * unlocked after the lookup before we go ahead and free it.
1191 */
1192 xfs_ilock(ip, XFS_ILOCK_EXCL);
1193 xfs_qm_dqdetach(ip);
1194 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1195
1196 __xfs_inode_free(ip);
1197 return error;
1198
1199out_ifunlock:
1200 xfs_ifunlock(ip);
1201out:
1202 xfs_iflags_clear(ip, XFS_IRECLAIM);
1203 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1204 /*
1205 * We could return -EAGAIN here to make reclaim rescan the inode tree in
1206 * a short while. However, this just burns CPU time scanning the tree
1207 * waiting for IO to complete and the reclaim work never goes back to
1208 * the idle state. Instead, return 0 to let the next scheduled
1209 * background reclaim attempt to reclaim the inode again.
1210 */
1211 return 0;
1212}
1213
1214/*
1215 * Walk the AGs and reclaim the inodes in them. Even if the filesystem is
1216 * corrupted, we still want to try to reclaim all the inodes. If we don't,
1217 * then a shut down during filesystem unmount reclaim walk leak all the
1218 * unreclaimed inodes.
1219 */
1220STATIC int
1221xfs_reclaim_inodes_ag(
1222 struct xfs_mount *mp,
1223 int flags,
1224 int *nr_to_scan)
1225{
1226 struct xfs_perag *pag;
1227 int error = 0;
1228 int last_error = 0;
1229 xfs_agnumber_t ag;
1230 int trylock = flags & SYNC_TRYLOCK;
1231 int skipped;
1232
1233restart:
1234 ag = 0;
1235 skipped = 0;
1236 while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
1237 unsigned long first_index = 0;
1238 int done = 0;
1239 int nr_found = 0;
1240
1241 ag = pag->pag_agno + 1;
1242
1243 if (trylock) {
1244 if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) {
1245 skipped++;
1246 xfs_perag_put(pag);
1247 continue;
1248 }
1249 first_index = pag->pag_ici_reclaim_cursor;
1250 } else
1251 mutex_lock(&pag->pag_ici_reclaim_lock);
1252
1253 do {
1254 struct xfs_inode *batch[XFS_LOOKUP_BATCH];
1255 int i;
1256
1257 rcu_read_lock();
1258 nr_found = radix_tree_gang_lookup_tag(
1259 &pag->pag_ici_root,
1260 (void **)batch, first_index,
1261 XFS_LOOKUP_BATCH,
1262 XFS_ICI_RECLAIM_TAG);
1263 if (!nr_found) {
1264 done = 1;
1265 rcu_read_unlock();
1266 break;
1267 }
1268
1269 /*
1270 * Grab the inodes before we drop the lock. if we found
1271 * nothing, nr == 0 and the loop will be skipped.
1272 */
1273 for (i = 0; i < nr_found; i++) {
1274 struct xfs_inode *ip = batch[i];
1275
1276 if (done || xfs_reclaim_inode_grab(ip, flags))
1277 batch[i] = NULL;
1278
1279 /*
1280 * Update the index for the next lookup. Catch
1281 * overflows into the next AG range which can
1282 * occur if we have inodes in the last block of
1283 * the AG and we are currently pointing to the
1284 * last inode.
1285 *
1286 * Because we may see inodes that are from the
1287 * wrong AG due to RCU freeing and
1288 * reallocation, only update the index if it
1289 * lies in this AG. It was a race that lead us
1290 * to see this inode, so another lookup from
1291 * the same index will not find it again.
1292 */
1293 if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
1294 pag->pag_agno)
1295 continue;
1296 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
1297 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
1298 done = 1;
1299 }
1300
1301 /* unlock now we've grabbed the inodes. */
1302 rcu_read_unlock();
1303
1304 for (i = 0; i < nr_found; i++) {
1305 if (!batch[i])
1306 continue;
1307 error = xfs_reclaim_inode(batch[i], pag, flags);
1308 if (error && last_error != -EFSCORRUPTED)
1309 last_error = error;
1310 }
1311
1312 *nr_to_scan -= XFS_LOOKUP_BATCH;
1313
1314 cond_resched();
1315
1316 } while (nr_found && !done && *nr_to_scan > 0);
1317
1318 if (trylock && !done)
1319 pag->pag_ici_reclaim_cursor = first_index;
1320 else
1321 pag->pag_ici_reclaim_cursor = 0;
1322 mutex_unlock(&pag->pag_ici_reclaim_lock);
1323 xfs_perag_put(pag);
1324 }
1325
1326 /*
1327 * if we skipped any AG, and we still have scan count remaining, do
1328 * another pass this time using blocking reclaim semantics (i.e
1329 * waiting on the reclaim locks and ignoring the reclaim cursors). This
1330 * ensure that when we get more reclaimers than AGs we block rather
1331 * than spin trying to execute reclaim.
1332 */
1333 if (skipped && (flags & SYNC_WAIT) && *nr_to_scan > 0) {
1334 trylock = 0;
1335 goto restart;
1336 }
1337 return last_error;
1338}
1339
1340int
1341xfs_reclaim_inodes(
1342 xfs_mount_t *mp,
1343 int mode)
1344{
1345 int nr_to_scan = INT_MAX;
1346
1347 return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan);
1348}
1349
1350/*
1351 * Scan a certain number of inodes for reclaim.
1352 *
1353 * When called we make sure that there is a background (fast) inode reclaim in
1354 * progress, while we will throttle the speed of reclaim via doing synchronous
1355 * reclaim of inodes. That means if we come across dirty inodes, we wait for
1356 * them to be cleaned, which we hope will not be very long due to the
1357 * background walker having already kicked the IO off on those dirty inodes.
1358 */
1359long
1360xfs_reclaim_inodes_nr(
1361 struct xfs_mount *mp,
1362 int nr_to_scan)
1363{
1364 /* kick background reclaimer and push the AIL */
1365 xfs_reclaim_work_queue(mp);
1366 xfs_ail_push_all(mp->m_ail);
1367
1368 return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
1369}
1370
1371/*
1372 * Return the number of reclaimable inodes in the filesystem for
1373 * the shrinker to determine how much to reclaim.
1374 */
1375int
1376xfs_reclaim_inodes_count(
1377 struct xfs_mount *mp)
1378{
1379 struct xfs_perag *pag;
1380 xfs_agnumber_t ag = 0;
1381 int reclaimable = 0;
1382
1383 while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
1384 ag = pag->pag_agno + 1;
1385 reclaimable += pag->pag_ici_reclaimable;
1386 xfs_perag_put(pag);
1387 }
1388 return reclaimable;
1389}
1390
1391STATIC int
1392xfs_inode_match_id(
1393 struct xfs_inode *ip,
1394 struct xfs_eofblocks *eofb)
1395{
1396 if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
1397 !uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1398 return 0;
1399
1400 if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
1401 !gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1402 return 0;
1403
1404 if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1405 xfs_get_projid(ip) != eofb->eof_prid)
1406 return 0;
1407
1408 return 1;
1409}
1410
1411/*
1412 * A union-based inode filtering algorithm. Process the inode if any of the
1413 * criteria match. This is for global/internal scans only.
1414 */
1415STATIC int
1416xfs_inode_match_id_union(
1417 struct xfs_inode *ip,
1418 struct xfs_eofblocks *eofb)
1419{
1420 if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
1421 uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1422 return 1;
1423
1424 if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
1425 gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1426 return 1;
1427
1428 if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1429 xfs_get_projid(ip) == eofb->eof_prid)
1430 return 1;
1431
1432 return 0;
1433}
1434
1435STATIC int
1436xfs_inode_free_eofblocks(
1437 struct xfs_inode *ip,
1438 int flags,
1439 void *args)
1440{
1441 int ret = 0;
1442 struct xfs_eofblocks *eofb = args;
1443 int match;
1444
1445 if (!xfs_can_free_eofblocks(ip, false)) {
1446 /* inode could be preallocated or append-only */
1447 trace_xfs_inode_free_eofblocks_invalid(ip);
1448 xfs_inode_clear_eofblocks_tag(ip);
1449 return 0;
1450 }
1451
1452 /*
1453 * If the mapping is dirty the operation can block and wait for some
1454 * time. Unless we are waiting, skip it.
1455 */
1456 if (!(flags & SYNC_WAIT) &&
1457 mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
1458 return 0;
1459
1460 if (eofb) {
1461 if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
1462 match = xfs_inode_match_id_union(ip, eofb);
1463 else
1464 match = xfs_inode_match_id(ip, eofb);
1465 if (!match)
1466 return 0;
1467
1468 /* skip the inode if the file size is too small */
1469 if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
1470 XFS_ISIZE(ip) < eofb->eof_min_file_size)
1471 return 0;
1472 }
1473
1474 /*
1475 * If the caller is waiting, return -EAGAIN to keep the background
1476 * scanner moving and revisit the inode in a subsequent pass.
1477 */
1478 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1479 if (flags & SYNC_WAIT)
1480 ret = -EAGAIN;
1481 return ret;
1482 }
1483 ret = xfs_free_eofblocks(ip);
1484 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1485
1486 return ret;
1487}
1488
1489static int
1490__xfs_icache_free_eofblocks(
1491 struct xfs_mount *mp,
1492 struct xfs_eofblocks *eofb,
1493 int (*execute)(struct xfs_inode *ip, int flags,
1494 void *args),
1495 int tag)
1496{
1497 int flags = SYNC_TRYLOCK;
1498
1499 if (eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC))
1500 flags = SYNC_WAIT;
1501
1502 return xfs_inode_ag_iterator_tag(mp, execute, flags,
1503 eofb, tag);
1504}
1505
1506int
1507xfs_icache_free_eofblocks(
1508 struct xfs_mount *mp,
1509 struct xfs_eofblocks *eofb)
1510{
1511 return __xfs_icache_free_eofblocks(mp, eofb, xfs_inode_free_eofblocks,
1512 XFS_ICI_EOFBLOCKS_TAG);
1513}
1514
1515/*
1516 * Run eofblocks scans on the quotas applicable to the inode. For inodes with
1517 * multiple quotas, we don't know exactly which quota caused an allocation
1518 * failure. We make a best effort by including each quota under low free space
1519 * conditions (less than 1% free space) in the scan.
1520 */
1521static int
1522__xfs_inode_free_quota_eofblocks(
1523 struct xfs_inode *ip,
1524 int (*execute)(struct xfs_mount *mp,
1525 struct xfs_eofblocks *eofb))
1526{
1527 int scan = 0;
1528 struct xfs_eofblocks eofb = {0};
1529 struct xfs_dquot *dq;
1530
1531 /*
1532 * Run a sync scan to increase effectiveness and use the union filter to
1533 * cover all applicable quotas in a single scan.
1534 */
1535 eofb.eof_flags = XFS_EOF_FLAGS_UNION|XFS_EOF_FLAGS_SYNC;
1536
1537 if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
1538 dq = xfs_inode_dquot(ip, XFS_DQ_USER);
1539 if (dq && xfs_dquot_lowsp(dq)) {
1540 eofb.eof_uid = VFS_I(ip)->i_uid;
1541 eofb.eof_flags |= XFS_EOF_FLAGS_UID;
1542 scan = 1;
1543 }
1544 }
1545
1546 if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
1547 dq = xfs_inode_dquot(ip, XFS_DQ_GROUP);
1548 if (dq && xfs_dquot_lowsp(dq)) {
1549 eofb.eof_gid = VFS_I(ip)->i_gid;
1550 eofb.eof_flags |= XFS_EOF_FLAGS_GID;
1551 scan = 1;
1552 }
1553 }
1554
1555 if (scan)
1556 execute(ip->i_mount, &eofb);
1557
1558 return scan;
1559}
1560
1561int
1562xfs_inode_free_quota_eofblocks(
1563 struct xfs_inode *ip)
1564{
1565 return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_eofblocks);
1566}
1567
1568static inline unsigned long
1569xfs_iflag_for_tag(
1570 int tag)
1571{
1572 switch (tag) {
1573 case XFS_ICI_EOFBLOCKS_TAG:
1574 return XFS_IEOFBLOCKS;
1575 case XFS_ICI_COWBLOCKS_TAG:
1576 return XFS_ICOWBLOCKS;
1577 default:
1578 ASSERT(0);
1579 return 0;
1580 }
1581}
1582
1583static void
1584__xfs_inode_set_blocks_tag(
1585 xfs_inode_t *ip,
1586 void (*execute)(struct xfs_mount *mp),
1587 void (*set_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
1588 int error, unsigned long caller_ip),
1589 int tag)
1590{
1591 struct xfs_mount *mp = ip->i_mount;
1592 struct xfs_perag *pag;
1593 int tagged;
1594
1595 /*
1596 * Don't bother locking the AG and looking up in the radix trees
1597 * if we already know that we have the tag set.
1598 */
1599 if (ip->i_flags & xfs_iflag_for_tag(tag))
1600 return;
1601 spin_lock(&ip->i_flags_lock);
1602 ip->i_flags |= xfs_iflag_for_tag(tag);
1603 spin_unlock(&ip->i_flags_lock);
1604
1605 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1606 spin_lock(&pag->pag_ici_lock);
1607
1608 tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
1609 radix_tree_tag_set(&pag->pag_ici_root,
1610 XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
1611 if (!tagged) {
1612 /* propagate the eofblocks tag up into the perag radix tree */
1613 spin_lock(&ip->i_mount->m_perag_lock);
1614 radix_tree_tag_set(&ip->i_mount->m_perag_tree,
1615 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
1616 tag);
1617 spin_unlock(&ip->i_mount->m_perag_lock);
1618
1619 /* kick off background trimming */
1620 execute(ip->i_mount);
1621
1622 set_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
1623 }
1624
1625 spin_unlock(&pag->pag_ici_lock);
1626 xfs_perag_put(pag);
1627}
1628
1629void
1630xfs_inode_set_eofblocks_tag(
1631 xfs_inode_t *ip)
1632{
1633 trace_xfs_inode_set_eofblocks_tag(ip);
1634 return __xfs_inode_set_blocks_tag(ip, xfs_queue_eofblocks,
1635 trace_xfs_perag_set_eofblocks,
1636 XFS_ICI_EOFBLOCKS_TAG);
1637}
1638
1639static void
1640__xfs_inode_clear_blocks_tag(
1641 xfs_inode_t *ip,
1642 void (*clear_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
1643 int error, unsigned long caller_ip),
1644 int tag)
1645{
1646 struct xfs_mount *mp = ip->i_mount;
1647 struct xfs_perag *pag;
1648
1649 spin_lock(&ip->i_flags_lock);
1650 ip->i_flags &= ~xfs_iflag_for_tag(tag);
1651 spin_unlock(&ip->i_flags_lock);
1652
1653 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1654 spin_lock(&pag->pag_ici_lock);
1655
1656 radix_tree_tag_clear(&pag->pag_ici_root,
1657 XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
1658 if (!radix_tree_tagged(&pag->pag_ici_root, tag)) {
1659 /* clear the eofblocks tag from the perag radix tree */
1660 spin_lock(&ip->i_mount->m_perag_lock);
1661 radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
1662 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
1663 tag);
1664 spin_unlock(&ip->i_mount->m_perag_lock);
1665 clear_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
1666 }
1667
1668 spin_unlock(&pag->pag_ici_lock);
1669 xfs_perag_put(pag);
1670}
1671
1672void
1673xfs_inode_clear_eofblocks_tag(
1674 xfs_inode_t *ip)
1675{
1676 trace_xfs_inode_clear_eofblocks_tag(ip);
1677 return __xfs_inode_clear_blocks_tag(ip,
1678 trace_xfs_perag_clear_eofblocks, XFS_ICI_EOFBLOCKS_TAG);
1679}
1680
1681/*
1682 * Set ourselves up to free CoW blocks from this file. If it's already clean
1683 * then we can bail out quickly, but otherwise we must back off if the file
1684 * is undergoing some kind of write.
1685 */
1686static bool
1687xfs_prep_free_cowblocks(
1688 struct xfs_inode *ip,
1689 struct xfs_ifork *ifp)
1690{
1691 /*
1692 * Just clear the tag if we have an empty cow fork or none at all. It's
1693 * possible the inode was fully unshared since it was originally tagged.
1694 */
1695 if (!xfs_is_reflink_inode(ip) || !ifp->if_bytes) {
1696 trace_xfs_inode_free_cowblocks_invalid(ip);
1697 xfs_inode_clear_cowblocks_tag(ip);
1698 return false;
1699 }
1700
1701 /*
1702 * If the mapping is dirty or under writeback we cannot touch the
1703 * CoW fork. Leave it alone if we're in the midst of a directio.
1704 */
1705 if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
1706 mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
1707 mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
1708 atomic_read(&VFS_I(ip)->i_dio_count))
1709 return false;
1710
1711 return true;
1712}
1713
1714/*
1715 * Automatic CoW Reservation Freeing
1716 *
1717 * These functions automatically garbage collect leftover CoW reservations
1718 * that were made on behalf of a cowextsize hint when we start to run out
1719 * of quota or when the reservations sit around for too long. If the file
1720 * has dirty pages or is undergoing writeback, its CoW reservations will
1721 * be retained.
1722 *
1723 * The actual garbage collection piggybacks off the same code that runs
1724 * the speculative EOF preallocation garbage collector.
1725 */
1726STATIC int
1727xfs_inode_free_cowblocks(
1728 struct xfs_inode *ip,
1729 int flags,
1730 void *args)
1731{
1732 struct xfs_eofblocks *eofb = args;
1733 struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
1734 int match;
1735 int ret = 0;
1736
1737 if (!xfs_prep_free_cowblocks(ip, ifp))
1738 return 0;
1739
1740 if (eofb) {
1741 if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
1742 match = xfs_inode_match_id_union(ip, eofb);
1743 else
1744 match = xfs_inode_match_id(ip, eofb);
1745 if (!match)
1746 return 0;
1747
1748 /* skip the inode if the file size is too small */
1749 if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
1750 XFS_ISIZE(ip) < eofb->eof_min_file_size)
1751 return 0;
1752 }
1753
1754 /* Free the CoW blocks */
1755 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1756 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
1757
1758 /*
1759 * Check again, nobody else should be able to dirty blocks or change
1760 * the reflink iflag now that we have the first two locks held.
1761 */
1762 if (xfs_prep_free_cowblocks(ip, ifp))
1763 ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
1764
1765 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1766 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1767
1768 return ret;
1769}
1770
1771int
1772xfs_icache_free_cowblocks(
1773 struct xfs_mount *mp,
1774 struct xfs_eofblocks *eofb)
1775{
1776 return __xfs_icache_free_eofblocks(mp, eofb, xfs_inode_free_cowblocks,
1777 XFS_ICI_COWBLOCKS_TAG);
1778}
1779
1780int
1781xfs_inode_free_quota_cowblocks(
1782 struct xfs_inode *ip)
1783{
1784 return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_cowblocks);
1785}
1786
1787void
1788xfs_inode_set_cowblocks_tag(
1789 xfs_inode_t *ip)
1790{
1791 trace_xfs_inode_set_cowblocks_tag(ip);
1792 return __xfs_inode_set_blocks_tag(ip, xfs_queue_cowblocks,
1793 trace_xfs_perag_set_cowblocks,
1794 XFS_ICI_COWBLOCKS_TAG);
1795}
1796
1797void
1798xfs_inode_clear_cowblocks_tag(
1799 xfs_inode_t *ip)
1800{
1801 trace_xfs_inode_clear_cowblocks_tag(ip);
1802 return __xfs_inode_clear_blocks_tag(ip,
1803 trace_xfs_perag_clear_cowblocks, XFS_ICI_COWBLOCKS_TAG);
1804}