Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_inode.h"
14#include "xfs_trans.h"
15#include "xfs_trans_priv.h"
16#include "xfs_inode_item.h"
17#include "xfs_quota.h"
18#include "xfs_trace.h"
19#include "xfs_icache.h"
20#include "xfs_bmap_util.h"
21#include "xfs_dquot_item.h"
22#include "xfs_dquot.h"
23#include "xfs_reflink.h"
24#include "xfs_ialloc.h"
25#include "xfs_ag.h"
26#include "xfs_log_priv.h"
27
28#include <linux/iversion.h>
29
30/* Radix tree tags for incore inode tree. */
31
32/* inode is to be reclaimed */
33#define XFS_ICI_RECLAIM_TAG 0
34/* Inode has speculative preallocations (posteof or cow) to clean. */
35#define XFS_ICI_BLOCKGC_TAG 1
36
37/*
38 * The goal for walking incore inodes. These can correspond with incore inode
39 * radix tree tags when convenient. Avoid existing XFS_IWALK namespace.
40 */
41enum xfs_icwalk_goal {
42 /* Goals directly associated with tagged inodes. */
43 XFS_ICWALK_BLOCKGC = XFS_ICI_BLOCKGC_TAG,
44 XFS_ICWALK_RECLAIM = XFS_ICI_RECLAIM_TAG,
45};
46
47static int xfs_icwalk(struct xfs_mount *mp,
48 enum xfs_icwalk_goal goal, struct xfs_icwalk *icw);
49static int xfs_icwalk_ag(struct xfs_perag *pag,
50 enum xfs_icwalk_goal goal, struct xfs_icwalk *icw);
51
52/*
53 * Private inode cache walk flags for struct xfs_icwalk. Must not
54 * coincide with XFS_ICWALK_FLAGS_VALID.
55 */
56
57/* Stop scanning after icw_scan_limit inodes. */
58#define XFS_ICWALK_FLAG_SCAN_LIMIT (1U << 28)
59
60#define XFS_ICWALK_FLAG_RECLAIM_SICK (1U << 27)
61#define XFS_ICWALK_FLAG_UNION (1U << 26) /* union filter algorithm */
62
63#define XFS_ICWALK_PRIVATE_FLAGS (XFS_ICWALK_FLAG_SCAN_LIMIT | \
64 XFS_ICWALK_FLAG_RECLAIM_SICK | \
65 XFS_ICWALK_FLAG_UNION)
66
67/*
68 * Allocate and initialise an xfs_inode.
69 */
70struct xfs_inode *
71xfs_inode_alloc(
72 struct xfs_mount *mp,
73 xfs_ino_t ino)
74{
75 struct xfs_inode *ip;
76
77 /*
78 * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
79 * and return NULL here on ENOMEM.
80 */
81 ip = alloc_inode_sb(mp->m_super, xfs_inode_cache, GFP_KERNEL | __GFP_NOFAIL);
82
83 if (inode_init_always(mp->m_super, VFS_I(ip))) {
84 kmem_cache_free(xfs_inode_cache, ip);
85 return NULL;
86 }
87
88 /* VFS doesn't initialise i_mode or i_state! */
89 VFS_I(ip)->i_mode = 0;
90 VFS_I(ip)->i_state = 0;
91 mapping_set_large_folios(VFS_I(ip)->i_mapping);
92
93 XFS_STATS_INC(mp, vn_active);
94 ASSERT(atomic_read(&ip->i_pincount) == 0);
95 ASSERT(ip->i_ino == 0);
96
97 /* initialise the xfs inode */
98 ip->i_ino = ino;
99 ip->i_mount = mp;
100 memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
101 ip->i_cowfp = NULL;
102 memset(&ip->i_af, 0, sizeof(ip->i_af));
103 ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
104 memset(&ip->i_df, 0, sizeof(ip->i_df));
105 ip->i_flags = 0;
106 ip->i_delayed_blks = 0;
107 ip->i_diflags2 = mp->m_ino_geo.new_diflags2;
108 ip->i_nblocks = 0;
109 ip->i_forkoff = 0;
110 ip->i_sick = 0;
111 ip->i_checked = 0;
112 INIT_WORK(&ip->i_ioend_work, xfs_end_io);
113 INIT_LIST_HEAD(&ip->i_ioend_list);
114 spin_lock_init(&ip->i_ioend_lock);
115 ip->i_next_unlinked = NULLAGINO;
116 ip->i_prev_unlinked = NULLAGINO;
117
118 return ip;
119}
120
121STATIC void
122xfs_inode_free_callback(
123 struct rcu_head *head)
124{
125 struct inode *inode = container_of(head, struct inode, i_rcu);
126 struct xfs_inode *ip = XFS_I(inode);
127
128 switch (VFS_I(ip)->i_mode & S_IFMT) {
129 case S_IFREG:
130 case S_IFDIR:
131 case S_IFLNK:
132 xfs_idestroy_fork(&ip->i_df);
133 break;
134 }
135
136 xfs_ifork_zap_attr(ip);
137
138 if (ip->i_cowfp) {
139 xfs_idestroy_fork(ip->i_cowfp);
140 kmem_cache_free(xfs_ifork_cache, ip->i_cowfp);
141 }
142 if (ip->i_itemp) {
143 ASSERT(!test_bit(XFS_LI_IN_AIL,
144 &ip->i_itemp->ili_item.li_flags));
145 xfs_inode_item_destroy(ip);
146 ip->i_itemp = NULL;
147 }
148
149 kmem_cache_free(xfs_inode_cache, ip);
150}
151
152static void
153__xfs_inode_free(
154 struct xfs_inode *ip)
155{
156 /* asserts to verify all state is correct here */
157 ASSERT(atomic_read(&ip->i_pincount) == 0);
158 ASSERT(!ip->i_itemp || list_empty(&ip->i_itemp->ili_item.li_bio_list));
159 XFS_STATS_DEC(ip->i_mount, vn_active);
160
161 call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
162}
163
164void
165xfs_inode_free(
166 struct xfs_inode *ip)
167{
168 ASSERT(!xfs_iflags_test(ip, XFS_IFLUSHING));
169
170 /*
171 * Because we use RCU freeing we need to ensure the inode always
172 * appears to be reclaimed with an invalid inode number when in the
173 * free state. The ip->i_flags_lock provides the barrier against lookup
174 * races.
175 */
176 spin_lock(&ip->i_flags_lock);
177 ip->i_flags = XFS_IRECLAIM;
178 ip->i_ino = 0;
179 spin_unlock(&ip->i_flags_lock);
180
181 __xfs_inode_free(ip);
182}
183
184/*
185 * Queue background inode reclaim work if there are reclaimable inodes and there
186 * isn't reclaim work already scheduled or in progress.
187 */
188static void
189xfs_reclaim_work_queue(
190 struct xfs_mount *mp)
191{
192
193 rcu_read_lock();
194 if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
195 queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work,
196 msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
197 }
198 rcu_read_unlock();
199}
200
201/*
202 * Background scanning to trim preallocated space. This is queued based on the
203 * 'speculative_prealloc_lifetime' tunable (5m by default).
204 */
205static inline void
206xfs_blockgc_queue(
207 struct xfs_perag *pag)
208{
209 struct xfs_mount *mp = pag->pag_mount;
210
211 if (!xfs_is_blockgc_enabled(mp))
212 return;
213
214 rcu_read_lock();
215 if (radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG))
216 queue_delayed_work(pag->pag_mount->m_blockgc_wq,
217 &pag->pag_blockgc_work,
218 msecs_to_jiffies(xfs_blockgc_secs * 1000));
219 rcu_read_unlock();
220}
221
222/* Set a tag on both the AG incore inode tree and the AG radix tree. */
223static void
224xfs_perag_set_inode_tag(
225 struct xfs_perag *pag,
226 xfs_agino_t agino,
227 unsigned int tag)
228{
229 struct xfs_mount *mp = pag->pag_mount;
230 bool was_tagged;
231
232 lockdep_assert_held(&pag->pag_ici_lock);
233
234 was_tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
235 radix_tree_tag_set(&pag->pag_ici_root, agino, tag);
236
237 if (tag == XFS_ICI_RECLAIM_TAG)
238 pag->pag_ici_reclaimable++;
239
240 if (was_tagged)
241 return;
242
243 /* propagate the tag up into the perag radix tree */
244 spin_lock(&mp->m_perag_lock);
245 radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno, tag);
246 spin_unlock(&mp->m_perag_lock);
247
248 /* start background work */
249 switch (tag) {
250 case XFS_ICI_RECLAIM_TAG:
251 xfs_reclaim_work_queue(mp);
252 break;
253 case XFS_ICI_BLOCKGC_TAG:
254 xfs_blockgc_queue(pag);
255 break;
256 }
257
258 trace_xfs_perag_set_inode_tag(mp, pag->pag_agno, tag, _RET_IP_);
259}
260
261/* Clear a tag on both the AG incore inode tree and the AG radix tree. */
262static void
263xfs_perag_clear_inode_tag(
264 struct xfs_perag *pag,
265 xfs_agino_t agino,
266 unsigned int tag)
267{
268 struct xfs_mount *mp = pag->pag_mount;
269
270 lockdep_assert_held(&pag->pag_ici_lock);
271
272 /*
273 * Reclaim can signal (with a null agino) that it cleared its own tag
274 * by removing the inode from the radix tree.
275 */
276 if (agino != NULLAGINO)
277 radix_tree_tag_clear(&pag->pag_ici_root, agino, tag);
278 else
279 ASSERT(tag == XFS_ICI_RECLAIM_TAG);
280
281 if (tag == XFS_ICI_RECLAIM_TAG)
282 pag->pag_ici_reclaimable--;
283
284 if (radix_tree_tagged(&pag->pag_ici_root, tag))
285 return;
286
287 /* clear the tag from the perag radix tree */
288 spin_lock(&mp->m_perag_lock);
289 radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno, tag);
290 spin_unlock(&mp->m_perag_lock);
291
292 trace_xfs_perag_clear_inode_tag(mp, pag->pag_agno, tag, _RET_IP_);
293}
294
295/*
296 * When we recycle a reclaimable inode, we need to re-initialise the VFS inode
297 * part of the structure. This is made more complex by the fact we store
298 * information about the on-disk values in the VFS inode and so we can't just
299 * overwrite the values unconditionally. Hence we save the parameters we
300 * need to retain across reinitialisation, and rewrite them into the VFS inode
301 * after reinitialisation even if it fails.
302 */
303static int
304xfs_reinit_inode(
305 struct xfs_mount *mp,
306 struct inode *inode)
307{
308 int error;
309 uint32_t nlink = inode->i_nlink;
310 uint32_t generation = inode->i_generation;
311 uint64_t version = inode_peek_iversion(inode);
312 umode_t mode = inode->i_mode;
313 dev_t dev = inode->i_rdev;
314 kuid_t uid = inode->i_uid;
315 kgid_t gid = inode->i_gid;
316
317 error = inode_init_always(mp->m_super, inode);
318
319 set_nlink(inode, nlink);
320 inode->i_generation = generation;
321 inode_set_iversion_queried(inode, version);
322 inode->i_mode = mode;
323 inode->i_rdev = dev;
324 inode->i_uid = uid;
325 inode->i_gid = gid;
326 mapping_set_large_folios(inode->i_mapping);
327 return error;
328}
329
330/*
331 * Carefully nudge an inode whose VFS state has been torn down back into a
332 * usable state. Drops the i_flags_lock and the rcu read lock.
333 */
334static int
335xfs_iget_recycle(
336 struct xfs_perag *pag,
337 struct xfs_inode *ip) __releases(&ip->i_flags_lock)
338{
339 struct xfs_mount *mp = ip->i_mount;
340 struct inode *inode = VFS_I(ip);
341 int error;
342
343 trace_xfs_iget_recycle(ip);
344
345 if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
346 return -EAGAIN;
347
348 /*
349 * We need to make it look like the inode is being reclaimed to prevent
350 * the actual reclaim workers from stomping over us while we recycle
351 * the inode. We can't clear the radix tree tag yet as it requires
352 * pag_ici_lock to be held exclusive.
353 */
354 ip->i_flags |= XFS_IRECLAIM;
355
356 spin_unlock(&ip->i_flags_lock);
357 rcu_read_unlock();
358
359 ASSERT(!rwsem_is_locked(&inode->i_rwsem));
360 error = xfs_reinit_inode(mp, inode);
361 xfs_iunlock(ip, XFS_ILOCK_EXCL);
362 if (error) {
363 /*
364 * Re-initializing the inode failed, and we are in deep
365 * trouble. Try to re-add it to the reclaim list.
366 */
367 rcu_read_lock();
368 spin_lock(&ip->i_flags_lock);
369 ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
370 ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
371 spin_unlock(&ip->i_flags_lock);
372 rcu_read_unlock();
373
374 trace_xfs_iget_recycle_fail(ip);
375 return error;
376 }
377
378 spin_lock(&pag->pag_ici_lock);
379 spin_lock(&ip->i_flags_lock);
380
381 /*
382 * Clear the per-lifetime state in the inode as we are now effectively
383 * a new inode and need to return to the initial state before reuse
384 * occurs.
385 */
386 ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
387 ip->i_flags |= XFS_INEW;
388 xfs_perag_clear_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
389 XFS_ICI_RECLAIM_TAG);
390 inode->i_state = I_NEW;
391 spin_unlock(&ip->i_flags_lock);
392 spin_unlock(&pag->pag_ici_lock);
393
394 return 0;
395}
396
397/*
398 * If we are allocating a new inode, then check what was returned is
399 * actually a free, empty inode. If we are not allocating an inode,
400 * then check we didn't find a free inode.
401 *
402 * Returns:
403 * 0 if the inode free state matches the lookup context
404 * -ENOENT if the inode is free and we are not allocating
405 * -EFSCORRUPTED if there is any state mismatch at all
406 */
407static int
408xfs_iget_check_free_state(
409 struct xfs_inode *ip,
410 int flags)
411{
412 if (flags & XFS_IGET_CREATE) {
413 /* should be a free inode */
414 if (VFS_I(ip)->i_mode != 0) {
415 xfs_warn(ip->i_mount,
416"Corruption detected! Free inode 0x%llx not marked free! (mode 0x%x)",
417 ip->i_ino, VFS_I(ip)->i_mode);
418 return -EFSCORRUPTED;
419 }
420
421 if (ip->i_nblocks != 0) {
422 xfs_warn(ip->i_mount,
423"Corruption detected! Free inode 0x%llx has blocks allocated!",
424 ip->i_ino);
425 return -EFSCORRUPTED;
426 }
427 return 0;
428 }
429
430 /* should be an allocated inode */
431 if (VFS_I(ip)->i_mode == 0)
432 return -ENOENT;
433
434 return 0;
435}
436
437/* Make all pending inactivation work start immediately. */
438static void
439xfs_inodegc_queue_all(
440 struct xfs_mount *mp)
441{
442 struct xfs_inodegc *gc;
443 int cpu;
444
445 for_each_online_cpu(cpu) {
446 gc = per_cpu_ptr(mp->m_inodegc, cpu);
447 if (!llist_empty(&gc->list))
448 mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0);
449 }
450}
451
452/*
453 * Check the validity of the inode we just found it the cache
454 */
455static int
456xfs_iget_cache_hit(
457 struct xfs_perag *pag,
458 struct xfs_inode *ip,
459 xfs_ino_t ino,
460 int flags,
461 int lock_flags) __releases(RCU)
462{
463 struct inode *inode = VFS_I(ip);
464 struct xfs_mount *mp = ip->i_mount;
465 int error;
466
467 /*
468 * check for re-use of an inode within an RCU grace period due to the
469 * radix tree nodes not being updated yet. We monitor for this by
470 * setting the inode number to zero before freeing the inode structure.
471 * If the inode has been reallocated and set up, then the inode number
472 * will not match, so check for that, too.
473 */
474 spin_lock(&ip->i_flags_lock);
475 if (ip->i_ino != ino)
476 goto out_skip;
477
478 /*
479 * If we are racing with another cache hit that is currently
480 * instantiating this inode or currently recycling it out of
481 * reclaimable state, wait for the initialisation to complete
482 * before continuing.
483 *
484 * If we're racing with the inactivation worker we also want to wait.
485 * If we're creating a new file, it's possible that the worker
486 * previously marked the inode as free on disk but hasn't finished
487 * updating the incore state yet. The AGI buffer will be dirty and
488 * locked to the icreate transaction, so a synchronous push of the
489 * inodegc workers would result in deadlock. For a regular iget, the
490 * worker is running already, so we might as well wait.
491 *
492 * XXX(hch): eventually we should do something equivalent to
493 * wait_on_inode to wait for these flags to be cleared
494 * instead of polling for it.
495 */
496 if (ip->i_flags & (XFS_INEW | XFS_IRECLAIM | XFS_INACTIVATING))
497 goto out_skip;
498
499 if (ip->i_flags & XFS_NEED_INACTIVE) {
500 /* Unlinked inodes cannot be re-grabbed. */
501 if (VFS_I(ip)->i_nlink == 0) {
502 error = -ENOENT;
503 goto out_error;
504 }
505 goto out_inodegc_flush;
506 }
507
508 /*
509 * Check the inode free state is valid. This also detects lookup
510 * racing with unlinks.
511 */
512 error = xfs_iget_check_free_state(ip, flags);
513 if (error)
514 goto out_error;
515
516 /* Skip inodes that have no vfs state. */
517 if ((flags & XFS_IGET_INCORE) &&
518 (ip->i_flags & XFS_IRECLAIMABLE))
519 goto out_skip;
520
521 /* The inode fits the selection criteria; process it. */
522 if (ip->i_flags & XFS_IRECLAIMABLE) {
523 /* Drops i_flags_lock and RCU read lock. */
524 error = xfs_iget_recycle(pag, ip);
525 if (error == -EAGAIN)
526 goto out_skip;
527 if (error)
528 return error;
529 } else {
530 /* If the VFS inode is being torn down, pause and try again. */
531 if (!igrab(inode))
532 goto out_skip;
533
534 /* We've got a live one. */
535 spin_unlock(&ip->i_flags_lock);
536 rcu_read_unlock();
537 trace_xfs_iget_hit(ip);
538 }
539
540 if (lock_flags != 0)
541 xfs_ilock(ip, lock_flags);
542
543 if (!(flags & XFS_IGET_INCORE))
544 xfs_iflags_clear(ip, XFS_ISTALE);
545 XFS_STATS_INC(mp, xs_ig_found);
546
547 return 0;
548
549out_skip:
550 trace_xfs_iget_skip(ip);
551 XFS_STATS_INC(mp, xs_ig_frecycle);
552 error = -EAGAIN;
553out_error:
554 spin_unlock(&ip->i_flags_lock);
555 rcu_read_unlock();
556 return error;
557
558out_inodegc_flush:
559 spin_unlock(&ip->i_flags_lock);
560 rcu_read_unlock();
561 /*
562 * Do not wait for the workers, because the caller could hold an AGI
563 * buffer lock. We're just going to sleep in a loop anyway.
564 */
565 if (xfs_is_inodegc_enabled(mp))
566 xfs_inodegc_queue_all(mp);
567 return -EAGAIN;
568}
569
570static int
571xfs_iget_cache_miss(
572 struct xfs_mount *mp,
573 struct xfs_perag *pag,
574 xfs_trans_t *tp,
575 xfs_ino_t ino,
576 struct xfs_inode **ipp,
577 int flags,
578 int lock_flags)
579{
580 struct xfs_inode *ip;
581 int error;
582 xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
583 int iflags;
584
585 ip = xfs_inode_alloc(mp, ino);
586 if (!ip)
587 return -ENOMEM;
588
589 error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
590 if (error)
591 goto out_destroy;
592
593 /*
594 * For version 5 superblocks, if we are initialising a new inode and we
595 * are not utilising the XFS_FEAT_IKEEP inode cluster mode, we can
596 * simply build the new inode core with a random generation number.
597 *
598 * For version 4 (and older) superblocks, log recovery is dependent on
599 * the i_flushiter field being initialised from the current on-disk
600 * value and hence we must also read the inode off disk even when
601 * initializing new inodes.
602 */
603 if (xfs_has_v3inodes(mp) &&
604 (flags & XFS_IGET_CREATE) && !xfs_has_ikeep(mp)) {
605 VFS_I(ip)->i_generation = get_random_u32();
606 } else {
607 struct xfs_buf *bp;
608
609 error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &bp);
610 if (error)
611 goto out_destroy;
612
613 error = xfs_inode_from_disk(ip,
614 xfs_buf_offset(bp, ip->i_imap.im_boffset));
615 if (!error)
616 xfs_buf_set_ref(bp, XFS_INO_REF);
617 xfs_trans_brelse(tp, bp);
618
619 if (error)
620 goto out_destroy;
621 }
622
623 trace_xfs_iget_miss(ip);
624
625 /*
626 * Check the inode free state is valid. This also detects lookup
627 * racing with unlinks.
628 */
629 error = xfs_iget_check_free_state(ip, flags);
630 if (error)
631 goto out_destroy;
632
633 /*
634 * Preload the radix tree so we can insert safely under the
635 * write spinlock. Note that we cannot sleep inside the preload
636 * region. Since we can be called from transaction context, don't
637 * recurse into the file system.
638 */
639 if (radix_tree_preload(GFP_NOFS)) {
640 error = -EAGAIN;
641 goto out_destroy;
642 }
643
644 /*
645 * Because the inode hasn't been added to the radix-tree yet it can't
646 * be found by another thread, so we can do the non-sleeping lock here.
647 */
648 if (lock_flags) {
649 if (!xfs_ilock_nowait(ip, lock_flags))
650 BUG();
651 }
652
653 /*
654 * These values must be set before inserting the inode into the radix
655 * tree as the moment it is inserted a concurrent lookup (allowed by the
656 * RCU locking mechanism) can find it and that lookup must see that this
657 * is an inode currently under construction (i.e. that XFS_INEW is set).
658 * The ip->i_flags_lock that protects the XFS_INEW flag forms the
659 * memory barrier that ensures this detection works correctly at lookup
660 * time.
661 */
662 iflags = XFS_INEW;
663 if (flags & XFS_IGET_DONTCACHE)
664 d_mark_dontcache(VFS_I(ip));
665 ip->i_udquot = NULL;
666 ip->i_gdquot = NULL;
667 ip->i_pdquot = NULL;
668 xfs_iflags_set(ip, iflags);
669
670 /* insert the new inode */
671 spin_lock(&pag->pag_ici_lock);
672 error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
673 if (unlikely(error)) {
674 WARN_ON(error != -EEXIST);
675 XFS_STATS_INC(mp, xs_ig_dup);
676 error = -EAGAIN;
677 goto out_preload_end;
678 }
679 spin_unlock(&pag->pag_ici_lock);
680 radix_tree_preload_end();
681
682 *ipp = ip;
683 return 0;
684
685out_preload_end:
686 spin_unlock(&pag->pag_ici_lock);
687 radix_tree_preload_end();
688 if (lock_flags)
689 xfs_iunlock(ip, lock_flags);
690out_destroy:
691 __destroy_inode(VFS_I(ip));
692 xfs_inode_free(ip);
693 return error;
694}
695
696/*
697 * Look up an inode by number in the given file system. The inode is looked up
698 * in the cache held in each AG. If the inode is found in the cache, initialise
699 * the vfs inode if necessary.
700 *
701 * If it is not in core, read it in from the file system's device, add it to the
702 * cache and initialise the vfs inode.
703 *
704 * The inode is locked according to the value of the lock_flags parameter.
705 * Inode lookup is only done during metadata operations and not as part of the
706 * data IO path. Hence we only allow locking of the XFS_ILOCK during lookup.
707 */
708int
709xfs_iget(
710 struct xfs_mount *mp,
711 struct xfs_trans *tp,
712 xfs_ino_t ino,
713 uint flags,
714 uint lock_flags,
715 struct xfs_inode **ipp)
716{
717 struct xfs_inode *ip;
718 struct xfs_perag *pag;
719 xfs_agino_t agino;
720 int error;
721
722 ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
723
724 /* reject inode numbers outside existing AGs */
725 if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
726 return -EINVAL;
727
728 XFS_STATS_INC(mp, xs_ig_attempts);
729
730 /* get the perag structure and ensure that it's inode capable */
731 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
732 agino = XFS_INO_TO_AGINO(mp, ino);
733
734again:
735 error = 0;
736 rcu_read_lock();
737 ip = radix_tree_lookup(&pag->pag_ici_root, agino);
738
739 if (ip) {
740 error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
741 if (error)
742 goto out_error_or_again;
743 } else {
744 rcu_read_unlock();
745 if (flags & XFS_IGET_INCORE) {
746 error = -ENODATA;
747 goto out_error_or_again;
748 }
749 XFS_STATS_INC(mp, xs_ig_missed);
750
751 error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
752 flags, lock_flags);
753 if (error)
754 goto out_error_or_again;
755 }
756 xfs_perag_put(pag);
757
758 *ipp = ip;
759
760 /*
761 * If we have a real type for an on-disk inode, we can setup the inode
762 * now. If it's a new inode being created, xfs_init_new_inode will
763 * handle it.
764 */
765 if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0)
766 xfs_setup_existing_inode(ip);
767 return 0;
768
769out_error_or_again:
770 if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) {
771 delay(1);
772 goto again;
773 }
774 xfs_perag_put(pag);
775 return error;
776}
777
778/*
779 * "Is this a cached inode that's also allocated?"
780 *
781 * Look up an inode by number in the given file system. If the inode is
782 * in cache and isn't in purgatory, return 1 if the inode is allocated
783 * and 0 if it is not. For all other cases (not in cache, being torn
784 * down, etc.), return a negative error code.
785 *
786 * The caller has to prevent inode allocation and freeing activity,
787 * presumably by locking the AGI buffer. This is to ensure that an
788 * inode cannot transition from allocated to freed until the caller is
789 * ready to allow that. If the inode is in an intermediate state (new,
790 * reclaimable, or being reclaimed), -EAGAIN will be returned; if the
791 * inode is not in the cache, -ENOENT will be returned. The caller must
792 * deal with these scenarios appropriately.
793 *
794 * This is a specialized use case for the online scrubber; if you're
795 * reading this, you probably want xfs_iget.
796 */
797int
798xfs_icache_inode_is_allocated(
799 struct xfs_mount *mp,
800 struct xfs_trans *tp,
801 xfs_ino_t ino,
802 bool *inuse)
803{
804 struct xfs_inode *ip;
805 int error;
806
807 error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip);
808 if (error)
809 return error;
810
811 *inuse = !!(VFS_I(ip)->i_mode);
812 xfs_irele(ip);
813 return 0;
814}
815
816/*
817 * Grab the inode for reclaim exclusively.
818 *
819 * We have found this inode via a lookup under RCU, so the inode may have
820 * already been freed, or it may be in the process of being recycled by
821 * xfs_iget(). In both cases, the inode will have XFS_IRECLAIM set. If the inode
822 * has been fully recycled by the time we get the i_flags_lock, XFS_IRECLAIMABLE
823 * will not be set. Hence we need to check for both these flag conditions to
824 * avoid inodes that are no longer reclaim candidates.
825 *
826 * Note: checking for other state flags here, under the i_flags_lock or not, is
827 * racy and should be avoided. Those races should be resolved only after we have
828 * ensured that we are able to reclaim this inode and the world can see that we
829 * are going to reclaim it.
830 *
831 * Return true if we grabbed it, false otherwise.
832 */
833static bool
834xfs_reclaim_igrab(
835 struct xfs_inode *ip,
836 struct xfs_icwalk *icw)
837{
838 ASSERT(rcu_read_lock_held());
839
840 spin_lock(&ip->i_flags_lock);
841 if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
842 __xfs_iflags_test(ip, XFS_IRECLAIM)) {
843 /* not a reclaim candidate. */
844 spin_unlock(&ip->i_flags_lock);
845 return false;
846 }
847
848 /* Don't reclaim a sick inode unless the caller asked for it. */
849 if (ip->i_sick &&
850 (!icw || !(icw->icw_flags & XFS_ICWALK_FLAG_RECLAIM_SICK))) {
851 spin_unlock(&ip->i_flags_lock);
852 return false;
853 }
854
855 __xfs_iflags_set(ip, XFS_IRECLAIM);
856 spin_unlock(&ip->i_flags_lock);
857 return true;
858}
859
860/*
861 * Inode reclaim is non-blocking, so the default action if progress cannot be
862 * made is to "requeue" the inode for reclaim by unlocking it and clearing the
863 * XFS_IRECLAIM flag. If we are in a shutdown state, we don't care about
864 * blocking anymore and hence we can wait for the inode to be able to reclaim
865 * it.
866 *
867 * We do no IO here - if callers require inodes to be cleaned they must push the
868 * AIL first to trigger writeback of dirty inodes. This enables writeback to be
869 * done in the background in a non-blocking manner, and enables memory reclaim
870 * to make progress without blocking.
871 */
872static void
873xfs_reclaim_inode(
874 struct xfs_inode *ip,
875 struct xfs_perag *pag)
876{
877 xfs_ino_t ino = ip->i_ino; /* for radix_tree_delete */
878
879 if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
880 goto out;
881 if (xfs_iflags_test_and_set(ip, XFS_IFLUSHING))
882 goto out_iunlock;
883
884 /*
885 * Check for log shutdown because aborting the inode can move the log
886 * tail and corrupt in memory state. This is fine if the log is shut
887 * down, but if the log is still active and only the mount is shut down
888 * then the in-memory log tail movement caused by the abort can be
889 * incorrectly propagated to disk.
890 */
891 if (xlog_is_shutdown(ip->i_mount->m_log)) {
892 xfs_iunpin_wait(ip);
893 xfs_iflush_shutdown_abort(ip);
894 goto reclaim;
895 }
896 if (xfs_ipincount(ip))
897 goto out_clear_flush;
898 if (!xfs_inode_clean(ip))
899 goto out_clear_flush;
900
901 xfs_iflags_clear(ip, XFS_IFLUSHING);
902reclaim:
903 trace_xfs_inode_reclaiming(ip);
904
905 /*
906 * Because we use RCU freeing we need to ensure the inode always appears
907 * to be reclaimed with an invalid inode number when in the free state.
908 * We do this as early as possible under the ILOCK so that
909 * xfs_iflush_cluster() and xfs_ifree_cluster() can be guaranteed to
910 * detect races with us here. By doing this, we guarantee that once
911 * xfs_iflush_cluster() or xfs_ifree_cluster() has locked XFS_ILOCK that
912 * it will see either a valid inode that will serialise correctly, or it
913 * will see an invalid inode that it can skip.
914 */
915 spin_lock(&ip->i_flags_lock);
916 ip->i_flags = XFS_IRECLAIM;
917 ip->i_ino = 0;
918 ip->i_sick = 0;
919 ip->i_checked = 0;
920 spin_unlock(&ip->i_flags_lock);
921
922 ASSERT(!ip->i_itemp || ip->i_itemp->ili_item.li_buf == NULL);
923 xfs_iunlock(ip, XFS_ILOCK_EXCL);
924
925 XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
926 /*
927 * Remove the inode from the per-AG radix tree.
928 *
929 * Because radix_tree_delete won't complain even if the item was never
930 * added to the tree assert that it's been there before to catch
931 * problems with the inode life time early on.
932 */
933 spin_lock(&pag->pag_ici_lock);
934 if (!radix_tree_delete(&pag->pag_ici_root,
935 XFS_INO_TO_AGINO(ip->i_mount, ino)))
936 ASSERT(0);
937 xfs_perag_clear_inode_tag(pag, NULLAGINO, XFS_ICI_RECLAIM_TAG);
938 spin_unlock(&pag->pag_ici_lock);
939
940 /*
941 * Here we do an (almost) spurious inode lock in order to coordinate
942 * with inode cache radix tree lookups. This is because the lookup
943 * can reference the inodes in the cache without taking references.
944 *
945 * We make that OK here by ensuring that we wait until the inode is
946 * unlocked after the lookup before we go ahead and free it.
947 */
948 xfs_ilock(ip, XFS_ILOCK_EXCL);
949 ASSERT(!ip->i_udquot && !ip->i_gdquot && !ip->i_pdquot);
950 xfs_iunlock(ip, XFS_ILOCK_EXCL);
951 ASSERT(xfs_inode_clean(ip));
952
953 __xfs_inode_free(ip);
954 return;
955
956out_clear_flush:
957 xfs_iflags_clear(ip, XFS_IFLUSHING);
958out_iunlock:
959 xfs_iunlock(ip, XFS_ILOCK_EXCL);
960out:
961 xfs_iflags_clear(ip, XFS_IRECLAIM);
962}
963
964/* Reclaim sick inodes if we're unmounting or the fs went down. */
965static inline bool
966xfs_want_reclaim_sick(
967 struct xfs_mount *mp)
968{
969 return xfs_is_unmounting(mp) || xfs_has_norecovery(mp) ||
970 xfs_is_shutdown(mp);
971}
972
973void
974xfs_reclaim_inodes(
975 struct xfs_mount *mp)
976{
977 struct xfs_icwalk icw = {
978 .icw_flags = 0,
979 };
980
981 if (xfs_want_reclaim_sick(mp))
982 icw.icw_flags |= XFS_ICWALK_FLAG_RECLAIM_SICK;
983
984 while (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
985 xfs_ail_push_all_sync(mp->m_ail);
986 xfs_icwalk(mp, XFS_ICWALK_RECLAIM, &icw);
987 }
988}
989
990/*
991 * The shrinker infrastructure determines how many inodes we should scan for
992 * reclaim. We want as many clean inodes ready to reclaim as possible, so we
993 * push the AIL here. We also want to proactively free up memory if we can to
994 * minimise the amount of work memory reclaim has to do so we kick the
995 * background reclaim if it isn't already scheduled.
996 */
997long
998xfs_reclaim_inodes_nr(
999 struct xfs_mount *mp,
1000 unsigned long nr_to_scan)
1001{
1002 struct xfs_icwalk icw = {
1003 .icw_flags = XFS_ICWALK_FLAG_SCAN_LIMIT,
1004 .icw_scan_limit = min_t(unsigned long, LONG_MAX, nr_to_scan),
1005 };
1006
1007 if (xfs_want_reclaim_sick(mp))
1008 icw.icw_flags |= XFS_ICWALK_FLAG_RECLAIM_SICK;
1009
1010 /* kick background reclaimer and push the AIL */
1011 xfs_reclaim_work_queue(mp);
1012 xfs_ail_push_all(mp->m_ail);
1013
1014 xfs_icwalk(mp, XFS_ICWALK_RECLAIM, &icw);
1015 return 0;
1016}
1017
1018/*
1019 * Return the number of reclaimable inodes in the filesystem for
1020 * the shrinker to determine how much to reclaim.
1021 */
1022long
1023xfs_reclaim_inodes_count(
1024 struct xfs_mount *mp)
1025{
1026 struct xfs_perag *pag;
1027 xfs_agnumber_t ag = 0;
1028 long reclaimable = 0;
1029
1030 while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
1031 ag = pag->pag_agno + 1;
1032 reclaimable += pag->pag_ici_reclaimable;
1033 xfs_perag_put(pag);
1034 }
1035 return reclaimable;
1036}
1037
1038STATIC bool
1039xfs_icwalk_match_id(
1040 struct xfs_inode *ip,
1041 struct xfs_icwalk *icw)
1042{
1043 if ((icw->icw_flags & XFS_ICWALK_FLAG_UID) &&
1044 !uid_eq(VFS_I(ip)->i_uid, icw->icw_uid))
1045 return false;
1046
1047 if ((icw->icw_flags & XFS_ICWALK_FLAG_GID) &&
1048 !gid_eq(VFS_I(ip)->i_gid, icw->icw_gid))
1049 return false;
1050
1051 if ((icw->icw_flags & XFS_ICWALK_FLAG_PRID) &&
1052 ip->i_projid != icw->icw_prid)
1053 return false;
1054
1055 return true;
1056}
1057
1058/*
1059 * A union-based inode filtering algorithm. Process the inode if any of the
1060 * criteria match. This is for global/internal scans only.
1061 */
1062STATIC bool
1063xfs_icwalk_match_id_union(
1064 struct xfs_inode *ip,
1065 struct xfs_icwalk *icw)
1066{
1067 if ((icw->icw_flags & XFS_ICWALK_FLAG_UID) &&
1068 uid_eq(VFS_I(ip)->i_uid, icw->icw_uid))
1069 return true;
1070
1071 if ((icw->icw_flags & XFS_ICWALK_FLAG_GID) &&
1072 gid_eq(VFS_I(ip)->i_gid, icw->icw_gid))
1073 return true;
1074
1075 if ((icw->icw_flags & XFS_ICWALK_FLAG_PRID) &&
1076 ip->i_projid == icw->icw_prid)
1077 return true;
1078
1079 return false;
1080}
1081
1082/*
1083 * Is this inode @ip eligible for eof/cow block reclamation, given some
1084 * filtering parameters @icw? The inode is eligible if @icw is null or
1085 * if the predicate functions match.
1086 */
1087static bool
1088xfs_icwalk_match(
1089 struct xfs_inode *ip,
1090 struct xfs_icwalk *icw)
1091{
1092 bool match;
1093
1094 if (!icw)
1095 return true;
1096
1097 if (icw->icw_flags & XFS_ICWALK_FLAG_UNION)
1098 match = xfs_icwalk_match_id_union(ip, icw);
1099 else
1100 match = xfs_icwalk_match_id(ip, icw);
1101 if (!match)
1102 return false;
1103
1104 /* skip the inode if the file size is too small */
1105 if ((icw->icw_flags & XFS_ICWALK_FLAG_MINFILESIZE) &&
1106 XFS_ISIZE(ip) < icw->icw_min_file_size)
1107 return false;
1108
1109 return true;
1110}
1111
1112/*
1113 * This is a fast pass over the inode cache to try to get reclaim moving on as
1114 * many inodes as possible in a short period of time. It kicks itself every few
1115 * seconds, as well as being kicked by the inode cache shrinker when memory
1116 * goes low.
1117 */
1118void
1119xfs_reclaim_worker(
1120 struct work_struct *work)
1121{
1122 struct xfs_mount *mp = container_of(to_delayed_work(work),
1123 struct xfs_mount, m_reclaim_work);
1124
1125 xfs_icwalk(mp, XFS_ICWALK_RECLAIM, NULL);
1126 xfs_reclaim_work_queue(mp);
1127}
1128
1129STATIC int
1130xfs_inode_free_eofblocks(
1131 struct xfs_inode *ip,
1132 struct xfs_icwalk *icw,
1133 unsigned int *lockflags)
1134{
1135 bool wait;
1136
1137 wait = icw && (icw->icw_flags & XFS_ICWALK_FLAG_SYNC);
1138
1139 if (!xfs_iflags_test(ip, XFS_IEOFBLOCKS))
1140 return 0;
1141
1142 /*
1143 * If the mapping is dirty the operation can block and wait for some
1144 * time. Unless we are waiting, skip it.
1145 */
1146 if (!wait && mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
1147 return 0;
1148
1149 if (!xfs_icwalk_match(ip, icw))
1150 return 0;
1151
1152 /*
1153 * If the caller is waiting, return -EAGAIN to keep the background
1154 * scanner moving and revisit the inode in a subsequent pass.
1155 */
1156 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1157 if (wait)
1158 return -EAGAIN;
1159 return 0;
1160 }
1161 *lockflags |= XFS_IOLOCK_EXCL;
1162
1163 if (xfs_can_free_eofblocks(ip, false))
1164 return xfs_free_eofblocks(ip);
1165
1166 /* inode could be preallocated or append-only */
1167 trace_xfs_inode_free_eofblocks_invalid(ip);
1168 xfs_inode_clear_eofblocks_tag(ip);
1169 return 0;
1170}
1171
1172static void
1173xfs_blockgc_set_iflag(
1174 struct xfs_inode *ip,
1175 unsigned long iflag)
1176{
1177 struct xfs_mount *mp = ip->i_mount;
1178 struct xfs_perag *pag;
1179
1180 ASSERT((iflag & ~(XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0);
1181
1182 /*
1183 * Don't bother locking the AG and looking up in the radix trees
1184 * if we already know that we have the tag set.
1185 */
1186 if (ip->i_flags & iflag)
1187 return;
1188 spin_lock(&ip->i_flags_lock);
1189 ip->i_flags |= iflag;
1190 spin_unlock(&ip->i_flags_lock);
1191
1192 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1193 spin_lock(&pag->pag_ici_lock);
1194
1195 xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
1196 XFS_ICI_BLOCKGC_TAG);
1197
1198 spin_unlock(&pag->pag_ici_lock);
1199 xfs_perag_put(pag);
1200}
1201
1202void
1203xfs_inode_set_eofblocks_tag(
1204 xfs_inode_t *ip)
1205{
1206 trace_xfs_inode_set_eofblocks_tag(ip);
1207 return xfs_blockgc_set_iflag(ip, XFS_IEOFBLOCKS);
1208}
1209
1210static void
1211xfs_blockgc_clear_iflag(
1212 struct xfs_inode *ip,
1213 unsigned long iflag)
1214{
1215 struct xfs_mount *mp = ip->i_mount;
1216 struct xfs_perag *pag;
1217 bool clear_tag;
1218
1219 ASSERT((iflag & ~(XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0);
1220
1221 spin_lock(&ip->i_flags_lock);
1222 ip->i_flags &= ~iflag;
1223 clear_tag = (ip->i_flags & (XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0;
1224 spin_unlock(&ip->i_flags_lock);
1225
1226 if (!clear_tag)
1227 return;
1228
1229 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1230 spin_lock(&pag->pag_ici_lock);
1231
1232 xfs_perag_clear_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
1233 XFS_ICI_BLOCKGC_TAG);
1234
1235 spin_unlock(&pag->pag_ici_lock);
1236 xfs_perag_put(pag);
1237}
1238
1239void
1240xfs_inode_clear_eofblocks_tag(
1241 xfs_inode_t *ip)
1242{
1243 trace_xfs_inode_clear_eofblocks_tag(ip);
1244 return xfs_blockgc_clear_iflag(ip, XFS_IEOFBLOCKS);
1245}
1246
1247/*
1248 * Set ourselves up to free CoW blocks from this file. If it's already clean
1249 * then we can bail out quickly, but otherwise we must back off if the file
1250 * is undergoing some kind of write.
1251 */
1252static bool
1253xfs_prep_free_cowblocks(
1254 struct xfs_inode *ip)
1255{
1256 /*
1257 * Just clear the tag if we have an empty cow fork or none at all. It's
1258 * possible the inode was fully unshared since it was originally tagged.
1259 */
1260 if (!xfs_inode_has_cow_data(ip)) {
1261 trace_xfs_inode_free_cowblocks_invalid(ip);
1262 xfs_inode_clear_cowblocks_tag(ip);
1263 return false;
1264 }
1265
1266 /*
1267 * If the mapping is dirty or under writeback we cannot touch the
1268 * CoW fork. Leave it alone if we're in the midst of a directio.
1269 */
1270 if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
1271 mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
1272 mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
1273 atomic_read(&VFS_I(ip)->i_dio_count))
1274 return false;
1275
1276 return true;
1277}
1278
1279/*
1280 * Automatic CoW Reservation Freeing
1281 *
1282 * These functions automatically garbage collect leftover CoW reservations
1283 * that were made on behalf of a cowextsize hint when we start to run out
1284 * of quota or when the reservations sit around for too long. If the file
1285 * has dirty pages or is undergoing writeback, its CoW reservations will
1286 * be retained.
1287 *
1288 * The actual garbage collection piggybacks off the same code that runs
1289 * the speculative EOF preallocation garbage collector.
1290 */
1291STATIC int
1292xfs_inode_free_cowblocks(
1293 struct xfs_inode *ip,
1294 struct xfs_icwalk *icw,
1295 unsigned int *lockflags)
1296{
1297 bool wait;
1298 int ret = 0;
1299
1300 wait = icw && (icw->icw_flags & XFS_ICWALK_FLAG_SYNC);
1301
1302 if (!xfs_iflags_test(ip, XFS_ICOWBLOCKS))
1303 return 0;
1304
1305 if (!xfs_prep_free_cowblocks(ip))
1306 return 0;
1307
1308 if (!xfs_icwalk_match(ip, icw))
1309 return 0;
1310
1311 /*
1312 * If the caller is waiting, return -EAGAIN to keep the background
1313 * scanner moving and revisit the inode in a subsequent pass.
1314 */
1315 if (!(*lockflags & XFS_IOLOCK_EXCL) &&
1316 !xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1317 if (wait)
1318 return -EAGAIN;
1319 return 0;
1320 }
1321 *lockflags |= XFS_IOLOCK_EXCL;
1322
1323 if (!xfs_ilock_nowait(ip, XFS_MMAPLOCK_EXCL)) {
1324 if (wait)
1325 return -EAGAIN;
1326 return 0;
1327 }
1328 *lockflags |= XFS_MMAPLOCK_EXCL;
1329
1330 /*
1331 * Check again, nobody else should be able to dirty blocks or change
1332 * the reflink iflag now that we have the first two locks held.
1333 */
1334 if (xfs_prep_free_cowblocks(ip))
1335 ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
1336 return ret;
1337}
1338
1339void
1340xfs_inode_set_cowblocks_tag(
1341 xfs_inode_t *ip)
1342{
1343 trace_xfs_inode_set_cowblocks_tag(ip);
1344 return xfs_blockgc_set_iflag(ip, XFS_ICOWBLOCKS);
1345}
1346
1347void
1348xfs_inode_clear_cowblocks_tag(
1349 xfs_inode_t *ip)
1350{
1351 trace_xfs_inode_clear_cowblocks_tag(ip);
1352 return xfs_blockgc_clear_iflag(ip, XFS_ICOWBLOCKS);
1353}
1354
1355/* Disable post-EOF and CoW block auto-reclamation. */
1356void
1357xfs_blockgc_stop(
1358 struct xfs_mount *mp)
1359{
1360 struct xfs_perag *pag;
1361 xfs_agnumber_t agno;
1362
1363 if (!xfs_clear_blockgc_enabled(mp))
1364 return;
1365
1366 for_each_perag(mp, agno, pag)
1367 cancel_delayed_work_sync(&pag->pag_blockgc_work);
1368 trace_xfs_blockgc_stop(mp, __return_address);
1369}
1370
1371/* Enable post-EOF and CoW block auto-reclamation. */
1372void
1373xfs_blockgc_start(
1374 struct xfs_mount *mp)
1375{
1376 struct xfs_perag *pag;
1377 xfs_agnumber_t agno;
1378
1379 if (xfs_set_blockgc_enabled(mp))
1380 return;
1381
1382 trace_xfs_blockgc_start(mp, __return_address);
1383 for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
1384 xfs_blockgc_queue(pag);
1385}
1386
1387/* Don't try to run block gc on an inode that's in any of these states. */
1388#define XFS_BLOCKGC_NOGRAB_IFLAGS (XFS_INEW | \
1389 XFS_NEED_INACTIVE | \
1390 XFS_INACTIVATING | \
1391 XFS_IRECLAIMABLE | \
1392 XFS_IRECLAIM)
1393/*
1394 * Decide if the given @ip is eligible for garbage collection of speculative
1395 * preallocations, and grab it if so. Returns true if it's ready to go or
1396 * false if we should just ignore it.
1397 */
1398static bool
1399xfs_blockgc_igrab(
1400 struct xfs_inode *ip)
1401{
1402 struct inode *inode = VFS_I(ip);
1403
1404 ASSERT(rcu_read_lock_held());
1405
1406 /* Check for stale RCU freed inode */
1407 spin_lock(&ip->i_flags_lock);
1408 if (!ip->i_ino)
1409 goto out_unlock_noent;
1410
1411 if (ip->i_flags & XFS_BLOCKGC_NOGRAB_IFLAGS)
1412 goto out_unlock_noent;
1413 spin_unlock(&ip->i_flags_lock);
1414
1415 /* nothing to sync during shutdown */
1416 if (xfs_is_shutdown(ip->i_mount))
1417 return false;
1418
1419 /* If we can't grab the inode, it must on it's way to reclaim. */
1420 if (!igrab(inode))
1421 return false;
1422
1423 /* inode is valid */
1424 return true;
1425
1426out_unlock_noent:
1427 spin_unlock(&ip->i_flags_lock);
1428 return false;
1429}
1430
1431/* Scan one incore inode for block preallocations that we can remove. */
1432static int
1433xfs_blockgc_scan_inode(
1434 struct xfs_inode *ip,
1435 struct xfs_icwalk *icw)
1436{
1437 unsigned int lockflags = 0;
1438 int error;
1439
1440 error = xfs_inode_free_eofblocks(ip, icw, &lockflags);
1441 if (error)
1442 goto unlock;
1443
1444 error = xfs_inode_free_cowblocks(ip, icw, &lockflags);
1445unlock:
1446 if (lockflags)
1447 xfs_iunlock(ip, lockflags);
1448 xfs_irele(ip);
1449 return error;
1450}
1451
1452/* Background worker that trims preallocated space. */
1453void
1454xfs_blockgc_worker(
1455 struct work_struct *work)
1456{
1457 struct xfs_perag *pag = container_of(to_delayed_work(work),
1458 struct xfs_perag, pag_blockgc_work);
1459 struct xfs_mount *mp = pag->pag_mount;
1460 int error;
1461
1462 trace_xfs_blockgc_worker(mp, __return_address);
1463
1464 error = xfs_icwalk_ag(pag, XFS_ICWALK_BLOCKGC, NULL);
1465 if (error)
1466 xfs_info(mp, "AG %u preallocation gc worker failed, err=%d",
1467 pag->pag_agno, error);
1468 xfs_blockgc_queue(pag);
1469}
1470
1471/*
1472 * Try to free space in the filesystem by purging inactive inodes, eofblocks
1473 * and cowblocks.
1474 */
1475int
1476xfs_blockgc_free_space(
1477 struct xfs_mount *mp,
1478 struct xfs_icwalk *icw)
1479{
1480 int error;
1481
1482 trace_xfs_blockgc_free_space(mp, icw, _RET_IP_);
1483
1484 error = xfs_icwalk(mp, XFS_ICWALK_BLOCKGC, icw);
1485 if (error)
1486 return error;
1487
1488 xfs_inodegc_flush(mp);
1489 return 0;
1490}
1491
1492/*
1493 * Reclaim all the free space that we can by scheduling the background blockgc
1494 * and inodegc workers immediately and waiting for them all to clear.
1495 */
1496void
1497xfs_blockgc_flush_all(
1498 struct xfs_mount *mp)
1499{
1500 struct xfs_perag *pag;
1501 xfs_agnumber_t agno;
1502
1503 trace_xfs_blockgc_flush_all(mp, __return_address);
1504
1505 /*
1506 * For each blockgc worker, move its queue time up to now. If it
1507 * wasn't queued, it will not be requeued. Then flush whatever's
1508 * left.
1509 */
1510 for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
1511 mod_delayed_work(pag->pag_mount->m_blockgc_wq,
1512 &pag->pag_blockgc_work, 0);
1513
1514 for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
1515 flush_delayed_work(&pag->pag_blockgc_work);
1516
1517 xfs_inodegc_flush(mp);
1518}
1519
1520/*
1521 * Run cow/eofblocks scans on the supplied dquots. We don't know exactly which
1522 * quota caused an allocation failure, so we make a best effort by including
1523 * each quota under low free space conditions (less than 1% free space) in the
1524 * scan.
1525 *
1526 * Callers must not hold any inode's ILOCK. If requesting a synchronous scan
1527 * (XFS_ICWALK_FLAG_SYNC), the caller also must not hold any inode's IOLOCK or
1528 * MMAPLOCK.
1529 */
1530int
1531xfs_blockgc_free_dquots(
1532 struct xfs_mount *mp,
1533 struct xfs_dquot *udqp,
1534 struct xfs_dquot *gdqp,
1535 struct xfs_dquot *pdqp,
1536 unsigned int iwalk_flags)
1537{
1538 struct xfs_icwalk icw = {0};
1539 bool do_work = false;
1540
1541 if (!udqp && !gdqp && !pdqp)
1542 return 0;
1543
1544 /*
1545 * Run a scan to free blocks using the union filter to cover all
1546 * applicable quotas in a single scan.
1547 */
1548 icw.icw_flags = XFS_ICWALK_FLAG_UNION | iwalk_flags;
1549
1550 if (XFS_IS_UQUOTA_ENFORCED(mp) && udqp && xfs_dquot_lowsp(udqp)) {
1551 icw.icw_uid = make_kuid(mp->m_super->s_user_ns, udqp->q_id);
1552 icw.icw_flags |= XFS_ICWALK_FLAG_UID;
1553 do_work = true;
1554 }
1555
1556 if (XFS_IS_UQUOTA_ENFORCED(mp) && gdqp && xfs_dquot_lowsp(gdqp)) {
1557 icw.icw_gid = make_kgid(mp->m_super->s_user_ns, gdqp->q_id);
1558 icw.icw_flags |= XFS_ICWALK_FLAG_GID;
1559 do_work = true;
1560 }
1561
1562 if (XFS_IS_PQUOTA_ENFORCED(mp) && pdqp && xfs_dquot_lowsp(pdqp)) {
1563 icw.icw_prid = pdqp->q_id;
1564 icw.icw_flags |= XFS_ICWALK_FLAG_PRID;
1565 do_work = true;
1566 }
1567
1568 if (!do_work)
1569 return 0;
1570
1571 return xfs_blockgc_free_space(mp, &icw);
1572}
1573
1574/* Run cow/eofblocks scans on the quotas attached to the inode. */
1575int
1576xfs_blockgc_free_quota(
1577 struct xfs_inode *ip,
1578 unsigned int iwalk_flags)
1579{
1580 return xfs_blockgc_free_dquots(ip->i_mount,
1581 xfs_inode_dquot(ip, XFS_DQTYPE_USER),
1582 xfs_inode_dquot(ip, XFS_DQTYPE_GROUP),
1583 xfs_inode_dquot(ip, XFS_DQTYPE_PROJ), iwalk_flags);
1584}
1585
1586/* XFS Inode Cache Walking Code */
1587
1588/*
1589 * The inode lookup is done in batches to keep the amount of lock traffic and
1590 * radix tree lookups to a minimum. The batch size is a trade off between
1591 * lookup reduction and stack usage. This is in the reclaim path, so we can't
1592 * be too greedy.
1593 */
1594#define XFS_LOOKUP_BATCH 32
1595
1596
1597/*
1598 * Decide if we want to grab this inode in anticipation of doing work towards
1599 * the goal.
1600 */
1601static inline bool
1602xfs_icwalk_igrab(
1603 enum xfs_icwalk_goal goal,
1604 struct xfs_inode *ip,
1605 struct xfs_icwalk *icw)
1606{
1607 switch (goal) {
1608 case XFS_ICWALK_BLOCKGC:
1609 return xfs_blockgc_igrab(ip);
1610 case XFS_ICWALK_RECLAIM:
1611 return xfs_reclaim_igrab(ip, icw);
1612 default:
1613 return false;
1614 }
1615}
1616
1617/*
1618 * Process an inode. Each processing function must handle any state changes
1619 * made by the icwalk igrab function. Return -EAGAIN to skip an inode.
1620 */
1621static inline int
1622xfs_icwalk_process_inode(
1623 enum xfs_icwalk_goal goal,
1624 struct xfs_inode *ip,
1625 struct xfs_perag *pag,
1626 struct xfs_icwalk *icw)
1627{
1628 int error = 0;
1629
1630 switch (goal) {
1631 case XFS_ICWALK_BLOCKGC:
1632 error = xfs_blockgc_scan_inode(ip, icw);
1633 break;
1634 case XFS_ICWALK_RECLAIM:
1635 xfs_reclaim_inode(ip, pag);
1636 break;
1637 }
1638 return error;
1639}
1640
1641/*
1642 * For a given per-AG structure @pag and a goal, grab qualifying inodes and
1643 * process them in some manner.
1644 */
1645static int
1646xfs_icwalk_ag(
1647 struct xfs_perag *pag,
1648 enum xfs_icwalk_goal goal,
1649 struct xfs_icwalk *icw)
1650{
1651 struct xfs_mount *mp = pag->pag_mount;
1652 uint32_t first_index;
1653 int last_error = 0;
1654 int skipped;
1655 bool done;
1656 int nr_found;
1657
1658restart:
1659 done = false;
1660 skipped = 0;
1661 if (goal == XFS_ICWALK_RECLAIM)
1662 first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);
1663 else
1664 first_index = 0;
1665 nr_found = 0;
1666 do {
1667 struct xfs_inode *batch[XFS_LOOKUP_BATCH];
1668 int error = 0;
1669 int i;
1670
1671 rcu_read_lock();
1672
1673 nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root,
1674 (void **) batch, first_index,
1675 XFS_LOOKUP_BATCH, goal);
1676 if (!nr_found) {
1677 done = true;
1678 rcu_read_unlock();
1679 break;
1680 }
1681
1682 /*
1683 * Grab the inodes before we drop the lock. if we found
1684 * nothing, nr == 0 and the loop will be skipped.
1685 */
1686 for (i = 0; i < nr_found; i++) {
1687 struct xfs_inode *ip = batch[i];
1688
1689 if (done || !xfs_icwalk_igrab(goal, ip, icw))
1690 batch[i] = NULL;
1691
1692 /*
1693 * Update the index for the next lookup. Catch
1694 * overflows into the next AG range which can occur if
1695 * we have inodes in the last block of the AG and we
1696 * are currently pointing to the last inode.
1697 *
1698 * Because we may see inodes that are from the wrong AG
1699 * due to RCU freeing and reallocation, only update the
1700 * index if it lies in this AG. It was a race that lead
1701 * us to see this inode, so another lookup from the
1702 * same index will not find it again.
1703 */
1704 if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
1705 continue;
1706 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
1707 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
1708 done = true;
1709 }
1710
1711 /* unlock now we've grabbed the inodes. */
1712 rcu_read_unlock();
1713
1714 for (i = 0; i < nr_found; i++) {
1715 if (!batch[i])
1716 continue;
1717 error = xfs_icwalk_process_inode(goal, batch[i], pag,
1718 icw);
1719 if (error == -EAGAIN) {
1720 skipped++;
1721 continue;
1722 }
1723 if (error && last_error != -EFSCORRUPTED)
1724 last_error = error;
1725 }
1726
1727 /* bail out if the filesystem is corrupted. */
1728 if (error == -EFSCORRUPTED)
1729 break;
1730
1731 cond_resched();
1732
1733 if (icw && (icw->icw_flags & XFS_ICWALK_FLAG_SCAN_LIMIT)) {
1734 icw->icw_scan_limit -= XFS_LOOKUP_BATCH;
1735 if (icw->icw_scan_limit <= 0)
1736 break;
1737 }
1738 } while (nr_found && !done);
1739
1740 if (goal == XFS_ICWALK_RECLAIM) {
1741 if (done)
1742 first_index = 0;
1743 WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index);
1744 }
1745
1746 if (skipped) {
1747 delay(1);
1748 goto restart;
1749 }
1750 return last_error;
1751}
1752
1753/* Walk all incore inodes to achieve a given goal. */
1754static int
1755xfs_icwalk(
1756 struct xfs_mount *mp,
1757 enum xfs_icwalk_goal goal,
1758 struct xfs_icwalk *icw)
1759{
1760 struct xfs_perag *pag;
1761 int error = 0;
1762 int last_error = 0;
1763 xfs_agnumber_t agno;
1764
1765 for_each_perag_tag(mp, agno, pag, goal) {
1766 error = xfs_icwalk_ag(pag, goal, icw);
1767 if (error) {
1768 last_error = error;
1769 if (error == -EFSCORRUPTED) {
1770 xfs_perag_put(pag);
1771 break;
1772 }
1773 }
1774 }
1775 return last_error;
1776 BUILD_BUG_ON(XFS_ICWALK_PRIVATE_FLAGS & XFS_ICWALK_FLAGS_VALID);
1777}
1778
1779#ifdef DEBUG
1780static void
1781xfs_check_delalloc(
1782 struct xfs_inode *ip,
1783 int whichfork)
1784{
1785 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
1786 struct xfs_bmbt_irec got;
1787 struct xfs_iext_cursor icur;
1788
1789 if (!ifp || !xfs_iext_lookup_extent(ip, ifp, 0, &icur, &got))
1790 return;
1791 do {
1792 if (isnullstartblock(got.br_startblock)) {
1793 xfs_warn(ip->i_mount,
1794 "ino %llx %s fork has delalloc extent at [0x%llx:0x%llx]",
1795 ip->i_ino,
1796 whichfork == XFS_DATA_FORK ? "data" : "cow",
1797 got.br_startoff, got.br_blockcount);
1798 }
1799 } while (xfs_iext_next_extent(ifp, &icur, &got));
1800}
1801#else
1802#define xfs_check_delalloc(ip, whichfork) do { } while (0)
1803#endif
1804
1805/* Schedule the inode for reclaim. */
1806static void
1807xfs_inodegc_set_reclaimable(
1808 struct xfs_inode *ip)
1809{
1810 struct xfs_mount *mp = ip->i_mount;
1811 struct xfs_perag *pag;
1812
1813 if (!xfs_is_shutdown(mp) && ip->i_delayed_blks) {
1814 xfs_check_delalloc(ip, XFS_DATA_FORK);
1815 xfs_check_delalloc(ip, XFS_COW_FORK);
1816 ASSERT(0);
1817 }
1818
1819 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1820 spin_lock(&pag->pag_ici_lock);
1821 spin_lock(&ip->i_flags_lock);
1822
1823 trace_xfs_inode_set_reclaimable(ip);
1824 ip->i_flags &= ~(XFS_NEED_INACTIVE | XFS_INACTIVATING);
1825 ip->i_flags |= XFS_IRECLAIMABLE;
1826 xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
1827 XFS_ICI_RECLAIM_TAG);
1828
1829 spin_unlock(&ip->i_flags_lock);
1830 spin_unlock(&pag->pag_ici_lock);
1831 xfs_perag_put(pag);
1832}
1833
1834/*
1835 * Free all speculative preallocations and possibly even the inode itself.
1836 * This is the last chance to make changes to an otherwise unreferenced file
1837 * before incore reclamation happens.
1838 */
1839static void
1840xfs_inodegc_inactivate(
1841 struct xfs_inode *ip)
1842{
1843 trace_xfs_inode_inactivating(ip);
1844 xfs_inactive(ip);
1845 xfs_inodegc_set_reclaimable(ip);
1846}
1847
1848void
1849xfs_inodegc_worker(
1850 struct work_struct *work)
1851{
1852 struct xfs_inodegc *gc = container_of(to_delayed_work(work),
1853 struct xfs_inodegc, work);
1854 struct llist_node *node = llist_del_all(&gc->list);
1855 struct xfs_inode *ip, *n;
1856 unsigned int nofs_flag;
1857
1858 WRITE_ONCE(gc->items, 0);
1859
1860 if (!node)
1861 return;
1862
1863 /*
1864 * We can allocate memory here while doing writeback on behalf of
1865 * memory reclaim. To avoid memory allocation deadlocks set the
1866 * task-wide nofs context for the following operations.
1867 */
1868 nofs_flag = memalloc_nofs_save();
1869
1870 ip = llist_entry(node, struct xfs_inode, i_gclist);
1871 trace_xfs_inodegc_worker(ip->i_mount, READ_ONCE(gc->shrinker_hits));
1872
1873 WRITE_ONCE(gc->shrinker_hits, 0);
1874 llist_for_each_entry_safe(ip, n, node, i_gclist) {
1875 xfs_iflags_set(ip, XFS_INACTIVATING);
1876 xfs_inodegc_inactivate(ip);
1877 }
1878
1879 memalloc_nofs_restore(nofs_flag);
1880}
1881
1882/*
1883 * Expedite all pending inodegc work to run immediately. This does not wait for
1884 * completion of the work.
1885 */
1886void
1887xfs_inodegc_push(
1888 struct xfs_mount *mp)
1889{
1890 if (!xfs_is_inodegc_enabled(mp))
1891 return;
1892 trace_xfs_inodegc_push(mp, __return_address);
1893 xfs_inodegc_queue_all(mp);
1894}
1895
1896/*
1897 * Force all currently queued inode inactivation work to run immediately and
1898 * wait for the work to finish.
1899 */
1900void
1901xfs_inodegc_flush(
1902 struct xfs_mount *mp)
1903{
1904 xfs_inodegc_push(mp);
1905 trace_xfs_inodegc_flush(mp, __return_address);
1906 flush_workqueue(mp->m_inodegc_wq);
1907}
1908
1909/*
1910 * Flush all the pending work and then disable the inode inactivation background
1911 * workers and wait for them to stop.
1912 */
1913void
1914xfs_inodegc_stop(
1915 struct xfs_mount *mp)
1916{
1917 if (!xfs_clear_inodegc_enabled(mp))
1918 return;
1919
1920 xfs_inodegc_queue_all(mp);
1921 drain_workqueue(mp->m_inodegc_wq);
1922
1923 trace_xfs_inodegc_stop(mp, __return_address);
1924}
1925
1926/*
1927 * Enable the inode inactivation background workers and schedule deferred inode
1928 * inactivation work if there is any.
1929 */
1930void
1931xfs_inodegc_start(
1932 struct xfs_mount *mp)
1933{
1934 if (xfs_set_inodegc_enabled(mp))
1935 return;
1936
1937 trace_xfs_inodegc_start(mp, __return_address);
1938 xfs_inodegc_queue_all(mp);
1939}
1940
1941#ifdef CONFIG_XFS_RT
1942static inline bool
1943xfs_inodegc_want_queue_rt_file(
1944 struct xfs_inode *ip)
1945{
1946 struct xfs_mount *mp = ip->i_mount;
1947
1948 if (!XFS_IS_REALTIME_INODE(ip))
1949 return false;
1950
1951 if (__percpu_counter_compare(&mp->m_frextents,
1952 mp->m_low_rtexts[XFS_LOWSP_5_PCNT],
1953 XFS_FDBLOCKS_BATCH) < 0)
1954 return true;
1955
1956 return false;
1957}
1958#else
1959# define xfs_inodegc_want_queue_rt_file(ip) (false)
1960#endif /* CONFIG_XFS_RT */
1961
1962/*
1963 * Schedule the inactivation worker when:
1964 *
1965 * - We've accumulated more than one inode cluster buffer's worth of inodes.
1966 * - There is less than 5% free space left.
1967 * - Any of the quotas for this inode are near an enforcement limit.
1968 */
1969static inline bool
1970xfs_inodegc_want_queue_work(
1971 struct xfs_inode *ip,
1972 unsigned int items)
1973{
1974 struct xfs_mount *mp = ip->i_mount;
1975
1976 if (items > mp->m_ino_geo.inodes_per_cluster)
1977 return true;
1978
1979 if (__percpu_counter_compare(&mp->m_fdblocks,
1980 mp->m_low_space[XFS_LOWSP_5_PCNT],
1981 XFS_FDBLOCKS_BATCH) < 0)
1982 return true;
1983
1984 if (xfs_inodegc_want_queue_rt_file(ip))
1985 return true;
1986
1987 if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_USER))
1988 return true;
1989
1990 if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_GROUP))
1991 return true;
1992
1993 if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_PROJ))
1994 return true;
1995
1996 return false;
1997}
1998
1999/*
2000 * Upper bound on the number of inodes in each AG that can be queued for
2001 * inactivation at any given time, to avoid monopolizing the workqueue.
2002 */
2003#define XFS_INODEGC_MAX_BACKLOG (4 * XFS_INODES_PER_CHUNK)
2004
2005/*
2006 * Make the frontend wait for inactivations when:
2007 *
2008 * - Memory shrinkers queued the inactivation worker and it hasn't finished.
2009 * - The queue depth exceeds the maximum allowable percpu backlog.
2010 *
2011 * Note: If the current thread is running a transaction, we don't ever want to
2012 * wait for other transactions because that could introduce a deadlock.
2013 */
2014static inline bool
2015xfs_inodegc_want_flush_work(
2016 struct xfs_inode *ip,
2017 unsigned int items,
2018 unsigned int shrinker_hits)
2019{
2020 if (current->journal_info)
2021 return false;
2022
2023 if (shrinker_hits > 0)
2024 return true;
2025
2026 if (items > XFS_INODEGC_MAX_BACKLOG)
2027 return true;
2028
2029 return false;
2030}
2031
2032/*
2033 * Queue a background inactivation worker if there are inodes that need to be
2034 * inactivated and higher level xfs code hasn't disabled the background
2035 * workers.
2036 */
2037static void
2038xfs_inodegc_queue(
2039 struct xfs_inode *ip)
2040{
2041 struct xfs_mount *mp = ip->i_mount;
2042 struct xfs_inodegc *gc;
2043 int items;
2044 unsigned int shrinker_hits;
2045 unsigned long queue_delay = 1;
2046
2047 trace_xfs_inode_set_need_inactive(ip);
2048 spin_lock(&ip->i_flags_lock);
2049 ip->i_flags |= XFS_NEED_INACTIVE;
2050 spin_unlock(&ip->i_flags_lock);
2051
2052 gc = get_cpu_ptr(mp->m_inodegc);
2053 llist_add(&ip->i_gclist, &gc->list);
2054 items = READ_ONCE(gc->items);
2055 WRITE_ONCE(gc->items, items + 1);
2056 shrinker_hits = READ_ONCE(gc->shrinker_hits);
2057
2058 /*
2059 * We queue the work while holding the current CPU so that the work
2060 * is scheduled to run on this CPU.
2061 */
2062 if (!xfs_is_inodegc_enabled(mp)) {
2063 put_cpu_ptr(gc);
2064 return;
2065 }
2066
2067 if (xfs_inodegc_want_queue_work(ip, items))
2068 queue_delay = 0;
2069
2070 trace_xfs_inodegc_queue(mp, __return_address);
2071 mod_delayed_work(mp->m_inodegc_wq, &gc->work, queue_delay);
2072 put_cpu_ptr(gc);
2073
2074 if (xfs_inodegc_want_flush_work(ip, items, shrinker_hits)) {
2075 trace_xfs_inodegc_throttle(mp, __return_address);
2076 flush_delayed_work(&gc->work);
2077 }
2078}
2079
2080/*
2081 * Fold the dead CPU inodegc queue into the current CPUs queue.
2082 */
2083void
2084xfs_inodegc_cpu_dead(
2085 struct xfs_mount *mp,
2086 unsigned int dead_cpu)
2087{
2088 struct xfs_inodegc *dead_gc, *gc;
2089 struct llist_node *first, *last;
2090 unsigned int count = 0;
2091
2092 dead_gc = per_cpu_ptr(mp->m_inodegc, dead_cpu);
2093 cancel_delayed_work_sync(&dead_gc->work);
2094
2095 if (llist_empty(&dead_gc->list))
2096 return;
2097
2098 first = dead_gc->list.first;
2099 last = first;
2100 while (last->next) {
2101 last = last->next;
2102 count++;
2103 }
2104 dead_gc->list.first = NULL;
2105 dead_gc->items = 0;
2106
2107 /* Add pending work to current CPU */
2108 gc = get_cpu_ptr(mp->m_inodegc);
2109 llist_add_batch(first, last, &gc->list);
2110 count += READ_ONCE(gc->items);
2111 WRITE_ONCE(gc->items, count);
2112
2113 if (xfs_is_inodegc_enabled(mp)) {
2114 trace_xfs_inodegc_queue(mp, __return_address);
2115 mod_delayed_work(mp->m_inodegc_wq, &gc->work, 0);
2116 }
2117 put_cpu_ptr(gc);
2118}
2119
2120/*
2121 * We set the inode flag atomically with the radix tree tag. Once we get tag
2122 * lookups on the radix tree, this inode flag can go away.
2123 *
2124 * We always use background reclaim here because even if the inode is clean, it
2125 * still may be under IO and hence we have wait for IO completion to occur
2126 * before we can reclaim the inode. The background reclaim path handles this
2127 * more efficiently than we can here, so simply let background reclaim tear down
2128 * all inodes.
2129 */
2130void
2131xfs_inode_mark_reclaimable(
2132 struct xfs_inode *ip)
2133{
2134 struct xfs_mount *mp = ip->i_mount;
2135 bool need_inactive;
2136
2137 XFS_STATS_INC(mp, vn_reclaim);
2138
2139 /*
2140 * We should never get here with any of the reclaim flags already set.
2141 */
2142 ASSERT_ALWAYS(!xfs_iflags_test(ip, XFS_ALL_IRECLAIM_FLAGS));
2143
2144 need_inactive = xfs_inode_needs_inactive(ip);
2145 if (need_inactive) {
2146 xfs_inodegc_queue(ip);
2147 return;
2148 }
2149
2150 /* Going straight to reclaim, so drop the dquots. */
2151 xfs_qm_dqdetach(ip);
2152 xfs_inodegc_set_reclaimable(ip);
2153}
2154
2155/*
2156 * Register a phony shrinker so that we can run background inodegc sooner when
2157 * there's memory pressure. Inactivation does not itself free any memory but
2158 * it does make inodes reclaimable, which eventually frees memory.
2159 *
2160 * The count function, seek value, and batch value are crafted to trigger the
2161 * scan function during the second round of scanning. Hopefully this means
2162 * that we reclaimed enough memory that initiating metadata transactions won't
2163 * make things worse.
2164 */
2165#define XFS_INODEGC_SHRINKER_COUNT (1UL << DEF_PRIORITY)
2166#define XFS_INODEGC_SHRINKER_BATCH ((XFS_INODEGC_SHRINKER_COUNT / 2) + 1)
2167
2168static unsigned long
2169xfs_inodegc_shrinker_count(
2170 struct shrinker *shrink,
2171 struct shrink_control *sc)
2172{
2173 struct xfs_mount *mp = container_of(shrink, struct xfs_mount,
2174 m_inodegc_shrinker);
2175 struct xfs_inodegc *gc;
2176 int cpu;
2177
2178 if (!xfs_is_inodegc_enabled(mp))
2179 return 0;
2180
2181 for_each_online_cpu(cpu) {
2182 gc = per_cpu_ptr(mp->m_inodegc, cpu);
2183 if (!llist_empty(&gc->list))
2184 return XFS_INODEGC_SHRINKER_COUNT;
2185 }
2186
2187 return 0;
2188}
2189
2190static unsigned long
2191xfs_inodegc_shrinker_scan(
2192 struct shrinker *shrink,
2193 struct shrink_control *sc)
2194{
2195 struct xfs_mount *mp = container_of(shrink, struct xfs_mount,
2196 m_inodegc_shrinker);
2197 struct xfs_inodegc *gc;
2198 int cpu;
2199 bool no_items = true;
2200
2201 if (!xfs_is_inodegc_enabled(mp))
2202 return SHRINK_STOP;
2203
2204 trace_xfs_inodegc_shrinker_scan(mp, sc, __return_address);
2205
2206 for_each_online_cpu(cpu) {
2207 gc = per_cpu_ptr(mp->m_inodegc, cpu);
2208 if (!llist_empty(&gc->list)) {
2209 unsigned int h = READ_ONCE(gc->shrinker_hits);
2210
2211 WRITE_ONCE(gc->shrinker_hits, h + 1);
2212 mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, 0);
2213 no_items = false;
2214 }
2215 }
2216
2217 /*
2218 * If there are no inodes to inactivate, we don't want the shrinker
2219 * to think there's deferred work to call us back about.
2220 */
2221 if (no_items)
2222 return LONG_MAX;
2223
2224 return SHRINK_STOP;
2225}
2226
2227/* Register a shrinker so we can accelerate inodegc and throttle queuing. */
2228int
2229xfs_inodegc_register_shrinker(
2230 struct xfs_mount *mp)
2231{
2232 struct shrinker *shrink = &mp->m_inodegc_shrinker;
2233
2234 shrink->count_objects = xfs_inodegc_shrinker_count;
2235 shrink->scan_objects = xfs_inodegc_shrinker_scan;
2236 shrink->seeks = 0;
2237 shrink->flags = SHRINKER_NONSLAB;
2238 shrink->batch = XFS_INODEGC_SHRINKER_BATCH;
2239
2240 return register_shrinker(shrink, "xfs-inodegc:%s", mp->m_super->s_id);
2241}