1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * (C) 1997 Linus Torvalds
4 * (C) 1999 Andrea Arcangeli <andrea@suse.de>
5 */
6 #include <linux/export.h>
7 #include <linux/fs.h>
8 #include <linux/filelock.h>
9 #include <linux/mm.h>
10 #include <linux/backing-dev.h>
11 #include <linux/hash.h>
12 #include <linux/swap.h>
13 #include <linux/security.h>
14 #include <linux/cdev.h>
15 #include <linux/memblock.h>
16 #include <linux/fsnotify.h>
17 #include <linux/mount.h>
18 #include <linux/posix_acl.h>
19 #include <linux/buffer_head.h> /* for inode_ha
20 #include <linux/ratelimit.h>
21 #include <linux/list_lru.h>
22 #include <linux/iversion.h>
23 #include <linux/rw_hint.h>
24 #include <trace/events/writeback.h>
25 #include "internal.h"
26
27 /*
28 * Inode locking rules:
29 *
30 * inode->i_lock protects:
31 * inode->i_state, inode->i_hash, __iget(),
32 * Inode LRU list locks protect:
33 * inode->i_sb->s_inode_lru, inode->i_lru
34 * inode->i_sb->s_inode_list_lock protects:
35 * inode->i_sb->s_inodes, inode->i_sb_list
36 * bdi->wb.list_lock protects:
37 * bdi->wb.b_{dirty,io,more_io,dirty_time},
38 * inode_hash_lock protects:
39 * inode_hashtable, inode->i_hash
40 *
41 * Lock ordering:
42 *
43 * inode->i_sb->s_inode_list_lock
44 * inode->i_lock
45 * Inode LRU list locks
46 *
47 * bdi->wb.list_lock
48 * inode->i_lock
49 *
50 * inode_hash_lock
51 * inode->i_sb->s_inode_list_lock
52 * inode->i_lock
53 *
54 * iunique_lock
55 * inode_hash_lock
56 */
57
58 static unsigned int i_hash_mask __ro_after_ini
59 static unsigned int i_hash_shift __ro_after_in
60 static struct hlist_head *inode_hashtable __ro
61 static __cacheline_aligned_in_smp DEFINE_SPINL
62
63 /*
64 * Empty aops. Can be used for the cases where
65 * define any of the address_space operations.
66 */
67 const struct address_space_operations empty_ao
68 };
69 EXPORT_SYMBOL(empty_aops);
70
71 static DEFINE_PER_CPU(unsigned long, nr_inodes
72 static DEFINE_PER_CPU(unsigned long, nr_unused
73
74 static struct kmem_cache *inode_cachep __ro_af
75
76 static long get_nr_inodes(void)
77 {
78 int i;
79 long sum = 0;
80 for_each_possible_cpu(i)
81 sum += per_cpu(nr_inodes, i);
82 return sum < 0 ? 0 : sum;
83 }
84
85 static inline long get_nr_inodes_unused(void)
86 {
87 int i;
88 long sum = 0;
89 for_each_possible_cpu(i)
90 sum += per_cpu(nr_unused, i);
91 return sum < 0 ? 0 : sum;
92 }
93
94 long get_nr_dirty_inodes(void)
95 {
96 /* not actually dirty inodes, but a wi
97 long nr_dirty = get_nr_inodes() - get_
98 return nr_dirty > 0 ? nr_dirty : 0;
99 }
100
101 /*
102 * Handle nr_inode sysctl
103 */
104 #ifdef CONFIG_SYSCTL
105 /*
106 * Statistics gathering..
107 */
108 static struct inodes_stat_t inodes_stat;
109
110 static int proc_nr_inodes(const struct ctl_tab
111 size_t *lenp, loff_t
112 {
113 inodes_stat.nr_inodes = get_nr_inodes(
114 inodes_stat.nr_unused = get_nr_inodes_
115 return proc_doulongvec_minmax(table, w
116 }
117
118 static struct ctl_table inodes_sysctls[] = {
119 {
120 .procname = "inode-nr",
121 .data = &inodes_stat
122 .maxlen = 2*sizeof(lon
123 .mode = 0444,
124 .proc_handler = proc_nr_inod
125 },
126 {
127 .procname = "inode-state
128 .data = &inodes_stat
129 .maxlen = 7*sizeof(lon
130 .mode = 0444,
131 .proc_handler = proc_nr_inod
132 },
133 };
134
135 static int __init init_fs_inode_sysctls(void)
136 {
137 register_sysctl_init("fs", inodes_sysc
138 return 0;
139 }
140 early_initcall(init_fs_inode_sysctls);
141 #endif
142
143 static int no_open(struct inode *inode, struct
144 {
145 return -ENXIO;
146 }
147
148 /**
149 * inode_init_always_gfp - perform inode struc
150 * @sb: superblock inode belongs to
151 * @inode: inode to initialise
152 * @gfp: allocation flags
153 *
154 * These are initializations that need to be d
155 * allocation as the fields are not initialise
156 * If there are additional allocations require
157 */
158 int inode_init_always_gfp(struct super_block *
159 {
160 static const struct inode_operations e
161 static const struct file_operations no
162 struct address_space *const mapping =
163
164 inode->i_sb = sb;
165 inode->i_blkbits = sb->s_blocksize_bit
166 inode->i_flags = 0;
167 inode->i_state = 0;
168 atomic64_set(&inode->i_sequence, 0);
169 atomic_set(&inode->i_count, 1);
170 inode->i_op = &empty_iops;
171 inode->i_fop = &no_open_fops;
172 inode->i_ino = 0;
173 inode->__i_nlink = 1;
174 inode->i_opflags = 0;
175 if (sb->s_xattr)
176 inode->i_opflags |= IOP_XATTR;
177 i_uid_write(inode, 0);
178 i_gid_write(inode, 0);
179 atomic_set(&inode->i_writecount, 0);
180 inode->i_size = 0;
181 inode->i_write_hint = WRITE_LIFE_NOT_S
182 inode->i_blocks = 0;
183 inode->i_bytes = 0;
184 inode->i_generation = 0;
185 inode->i_pipe = NULL;
186 inode->i_cdev = NULL;
187 inode->i_link = NULL;
188 inode->i_dir_seq = 0;
189 inode->i_rdev = 0;
190 inode->dirtied_when = 0;
191
192 #ifdef CONFIG_CGROUP_WRITEBACK
193 inode->i_wb_frn_winner = 0;
194 inode->i_wb_frn_avg_time = 0;
195 inode->i_wb_frn_history = 0;
196 #endif
197
198 spin_lock_init(&inode->i_lock);
199 lockdep_set_class(&inode->i_lock, &sb-
200
201 init_rwsem(&inode->i_rwsem);
202 lockdep_set_class(&inode->i_rwsem, &sb
203
204 atomic_set(&inode->i_dio_count, 0);
205
206 mapping->a_ops = &empty_aops;
207 mapping->host = inode;
208 mapping->flags = 0;
209 mapping->wb_err = 0;
210 atomic_set(&mapping->i_mmap_writable,
211 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
212 atomic_set(&mapping->nr_thps, 0);
213 #endif
214 mapping_set_gfp_mask(mapping, GFP_HIGH
215 mapping->i_private_data = NULL;
216 mapping->writeback_index = 0;
217 init_rwsem(&mapping->invalidate_lock);
218 lockdep_set_class_and_name(&mapping->i
219 &sb->s_type
220 "mapping.in
221 if (sb->s_iflags & SB_I_STABLE_WRITES)
222 mapping_set_stable_writes(mapp
223 inode->i_private = NULL;
224 inode->i_mapping = mapping;
225 INIT_HLIST_HEAD(&inode->i_dentry);
226 #ifdef CONFIG_FS_POSIX_ACL
227 inode->i_acl = inode->i_default_acl =
228 #endif
229
230 #ifdef CONFIG_FSNOTIFY
231 inode->i_fsnotify_mask = 0;
232 #endif
233 inode->i_flctx = NULL;
234
235 if (unlikely(security_inode_alloc(inod
236 return -ENOMEM;
237
238 this_cpu_inc(nr_inodes);
239
240 return 0;
241 }
242 EXPORT_SYMBOL(inode_init_always_gfp);
243
244 void free_inode_nonrcu(struct inode *inode)
245 {
246 kmem_cache_free(inode_cachep, inode);
247 }
248 EXPORT_SYMBOL(free_inode_nonrcu);
249
250 static void i_callback(struct rcu_head *head)
251 {
252 struct inode *inode = container_of(hea
253 if (inode->free_inode)
254 inode->free_inode(inode);
255 else
256 free_inode_nonrcu(inode);
257 }
258
259 static struct inode *alloc_inode(struct super_
260 {
261 const struct super_operations *ops = s
262 struct inode *inode;
263
264 if (ops->alloc_inode)
265 inode = ops->alloc_inode(sb);
266 else
267 inode = alloc_inode_sb(sb, ino
268
269 if (!inode)
270 return NULL;
271
272 if (unlikely(inode_init_always(sb, ino
273 if (ops->destroy_inode) {
274 ops->destroy_inode(ino
275 if (!ops->free_inode)
276 return NULL;
277 }
278 inode->free_inode = ops->free_
279 i_callback(&inode->i_rcu);
280 return NULL;
281 }
282
283 return inode;
284 }
285
286 void __destroy_inode(struct inode *inode)
287 {
288 BUG_ON(inode_has_buffers(inode));
289 inode_detach_wb(inode);
290 security_inode_free(inode);
291 fsnotify_inode_delete(inode);
292 locks_free_lock_context(inode);
293 if (!inode->i_nlink) {
294 WARN_ON(atomic_long_read(&inod
295 atomic_long_dec(&inode->i_sb->
296 }
297
298 #ifdef CONFIG_FS_POSIX_ACL
299 if (inode->i_acl && !is_uncached_acl(i
300 posix_acl_release(inode->i_acl
301 if (inode->i_default_acl && !is_uncach
302 posix_acl_release(inode->i_def
303 #endif
304 this_cpu_dec(nr_inodes);
305 }
306 EXPORT_SYMBOL(__destroy_inode);
307
308 static void destroy_inode(struct inode *inode)
309 {
310 const struct super_operations *ops = i
311
312 BUG_ON(!list_empty(&inode->i_lru));
313 __destroy_inode(inode);
314 if (ops->destroy_inode) {
315 ops->destroy_inode(inode);
316 if (!ops->free_inode)
317 return;
318 }
319 inode->free_inode = ops->free_inode;
320 call_rcu(&inode->i_rcu, i_callback);
321 }
322
323 /**
324 * drop_nlink - directly drop an inode's link
325 * @inode: inode
326 *
327 * This is a low-level filesystem helper to re
328 * direct filesystem manipulation of i_nlink.
329 * where we are attempting to track writes to
330 * filesystem, a decrement to zero means an im
331 * write when the file is truncated and actual
332 * on the filesystem.
333 */
334 void drop_nlink(struct inode *inode)
335 {
336 WARN_ON(inode->i_nlink == 0);
337 inode->__i_nlink--;
338 if (!inode->i_nlink)
339 atomic_long_inc(&inode->i_sb->
340 }
341 EXPORT_SYMBOL(drop_nlink);
342
343 /**
344 * clear_nlink - directly zero an inode's link
345 * @inode: inode
346 *
347 * This is a low-level filesystem helper to re
348 * direct filesystem manipulation of i_nlink.
349 * drop_nlink() for why we care about i_nlink
350 */
351 void clear_nlink(struct inode *inode)
352 {
353 if (inode->i_nlink) {
354 inode->__i_nlink = 0;
355 atomic_long_inc(&inode->i_sb->
356 }
357 }
358 EXPORT_SYMBOL(clear_nlink);
359
360 /**
361 * set_nlink - directly set an inode's link co
362 * @inode: inode
363 * @nlink: new nlink (should be non-zero)
364 *
365 * This is a low-level filesystem helper to re
366 * direct filesystem manipulation of i_nlink.
367 */
368 void set_nlink(struct inode *inode, unsigned i
369 {
370 if (!nlink) {
371 clear_nlink(inode);
372 } else {
373 /* Yes, some filesystems do ch
374 if (inode->i_nlink == 0)
375 atomic_long_dec(&inode
376
377 inode->__i_nlink = nlink;
378 }
379 }
380 EXPORT_SYMBOL(set_nlink);
381
382 /**
383 * inc_nlink - directly increment an inode's l
384 * @inode: inode
385 *
386 * This is a low-level filesystem helper to re
387 * direct filesystem manipulation of i_nlink.
388 * it is only here for parity with dec_nlink()
389 */
390 void inc_nlink(struct inode *inode)
391 {
392 if (unlikely(inode->i_nlink == 0)) {
393 WARN_ON(!(inode->i_state & I_L
394 atomic_long_dec(&inode->i_sb->
395 }
396
397 inode->__i_nlink++;
398 }
399 EXPORT_SYMBOL(inc_nlink);
400
401 static void __address_space_init_once(struct a
402 {
403 xa_init_flags(&mapping->i_pages, XA_FL
404 init_rwsem(&mapping->i_mmap_rwsem);
405 INIT_LIST_HEAD(&mapping->i_private_lis
406 spin_lock_init(&mapping->i_private_loc
407 mapping->i_mmap = RB_ROOT_CACHED;
408 }
409
410 void address_space_init_once(struct address_sp
411 {
412 memset(mapping, 0, sizeof(*mapping));
413 __address_space_init_once(mapping);
414 }
415 EXPORT_SYMBOL(address_space_init_once);
416
417 /*
418 * These are initializations that only need to
419 * once, because the fields are idempotent acr
420 * of the inode, so let the slab aware of that
421 */
422 void inode_init_once(struct inode *inode)
423 {
424 memset(inode, 0, sizeof(*inode));
425 INIT_HLIST_NODE(&inode->i_hash);
426 INIT_LIST_HEAD(&inode->i_devices);
427 INIT_LIST_HEAD(&inode->i_io_list);
428 INIT_LIST_HEAD(&inode->i_wb_list);
429 INIT_LIST_HEAD(&inode->i_lru);
430 INIT_LIST_HEAD(&inode->i_sb_list);
431 __address_space_init_once(&inode->i_da
432 i_size_ordered_init(inode);
433 }
434 EXPORT_SYMBOL(inode_init_once);
435
436 static void init_once(void *foo)
437 {
438 struct inode *inode = (struct inode *)
439
440 inode_init_once(inode);
441 }
442
443 /*
444 * get additional reference to inode; caller m
445 */
446 void ihold(struct inode *inode)
447 {
448 WARN_ON(atomic_inc_return(&inode->i_co
449 }
450 EXPORT_SYMBOL(ihold);
451
452 static void __inode_add_lru(struct inode *inod
453 {
454 if (inode->i_state & (I_DIRTY_ALL | I_
455 return;
456 if (atomic_read(&inode->i_count))
457 return;
458 if (!(inode->i_sb->s_flags & SB_ACTIVE
459 return;
460 if (!mapping_shrinkable(&inode->i_data
461 return;
462
463 if (list_lru_add_obj(&inode->i_sb->s_i
464 this_cpu_inc(nr_unused);
465 else if (rotate)
466 inode->i_state |= I_REFERENCED
467 }
468
469 struct wait_queue_head *inode_bit_waitqueue(st
470 st
471 {
472 void *bit_address;
473
474 bit_address = inode_state_wait_address
475 init_wait_var_entry(wqe, bit_address,
476 return __var_waitqueue(bit_address);
477 }
478 EXPORT_SYMBOL(inode_bit_waitqueue);
479
480 /*
481 * Add inode to LRU if needed (inode is unused
482 *
483 * Needs inode->i_lock held.
484 */
485 void inode_add_lru(struct inode *inode)
486 {
487 __inode_add_lru(inode, false);
488 }
489
490 static void inode_lru_list_del(struct inode *i
491 {
492 if (list_lru_del_obj(&inode->i_sb->s_i
493 this_cpu_dec(nr_unused);
494 }
495
496 static void inode_pin_lru_isolating(struct ino
497 {
498 lockdep_assert_held(&inode->i_lock);
499 WARN_ON(inode->i_state & (I_LRU_ISOLAT
500 inode->i_state |= I_LRU_ISOLATING;
501 }
502
503 static void inode_unpin_lru_isolating(struct i
504 {
505 spin_lock(&inode->i_lock);
506 WARN_ON(!(inode->i_state & I_LRU_ISOLA
507 inode->i_state &= ~I_LRU_ISOLATING;
508 /* Called with inode->i_lock which ens
509 inode_wake_up_bit(inode, __I_LRU_ISOLA
510 spin_unlock(&inode->i_lock);
511 }
512
513 static void inode_wait_for_lru_isolating(struc
514 {
515 struct wait_bit_queue_entry wqe;
516 struct wait_queue_head *wq_head;
517
518 lockdep_assert_held(&inode->i_lock);
519 if (!(inode->i_state & I_LRU_ISOLATING
520 return;
521
522 wq_head = inode_bit_waitqueue(&wqe, in
523 for (;;) {
524 prepare_to_wait_event(wq_head,
525 /*
526 * Checking I_LRU_ISOLATING wi
527 * memory ordering.
528 */
529 if (!(inode->i_state & I_LRU_I
530 break;
531 spin_unlock(&inode->i_lock);
532 schedule();
533 spin_lock(&inode->i_lock);
534 }
535 finish_wait(wq_head, &wqe.wq_entry);
536 WARN_ON(inode->i_state & I_LRU_ISOLATI
537 }
538
539 /**
540 * inode_sb_list_add - add inode to the superb
541 * @inode: inode to add
542 */
543 void inode_sb_list_add(struct inode *inode)
544 {
545 spin_lock(&inode->i_sb->s_inode_list_l
546 list_add(&inode->i_sb_list, &inode->i_
547 spin_unlock(&inode->i_sb->s_inode_list
548 }
549 EXPORT_SYMBOL_GPL(inode_sb_list_add);
550
551 static inline void inode_sb_list_del(struct in
552 {
553 if (!list_empty(&inode->i_sb_list)) {
554 spin_lock(&inode->i_sb->s_inod
555 list_del_init(&inode->i_sb_lis
556 spin_unlock(&inode->i_sb->s_in
557 }
558 }
559
560 static unsigned long hash(struct super_block *
561 {
562 unsigned long tmp;
563
564 tmp = (hashval * (unsigned long)sb) ^
565 L1_CACHE_BYTES;
566 tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME
567 return tmp & i_hash_mask;
568 }
569
570 /**
571 * __insert_inode_hash - hash an inode
572 * @inode: unhashed inode
573 * @hashval: unsigned long value used to
574 * inode_hashtable.
575 *
576 * Add an inode to the inode hash for thi
577 */
578 void __insert_inode_hash(struct inode *inode,
579 {
580 struct hlist_head *b = inode_hashtable
581
582 spin_lock(&inode_hash_lock);
583 spin_lock(&inode->i_lock);
584 hlist_add_head_rcu(&inode->i_hash, b);
585 spin_unlock(&inode->i_lock);
586 spin_unlock(&inode_hash_lock);
587 }
588 EXPORT_SYMBOL(__insert_inode_hash);
589
590 /**
591 * __remove_inode_hash - remove an inode
592 * @inode: inode to unhash
593 *
594 * Remove an inode from the superblock.
595 */
596 void __remove_inode_hash(struct inode *inode)
597 {
598 spin_lock(&inode_hash_lock);
599 spin_lock(&inode->i_lock);
600 hlist_del_init_rcu(&inode->i_hash);
601 spin_unlock(&inode->i_lock);
602 spin_unlock(&inode_hash_lock);
603 }
604 EXPORT_SYMBOL(__remove_inode_hash);
605
606 void dump_mapping(const struct address_space *
607 {
608 struct inode *host;
609 const struct address_space_operations
610 struct hlist_node *dentry_first;
611 struct dentry *dentry_ptr;
612 struct dentry dentry;
613 char fname[64] = {};
614 unsigned long ino;
615
616 /*
617 * If mapping is an invalid pointer, w
618 * accessing it, so probe everything d
619 */
620 if (get_kernel_nofault(host, &mapping-
621 get_kernel_nofault(a_ops, &mapping
622 pr_warn("invalid mapping:%px\n
623 return;
624 }
625
626 if (!host) {
627 pr_warn("aops:%ps\n", a_ops);
628 return;
629 }
630
631 if (get_kernel_nofault(dentry_first, &
632 get_kernel_nofault(ino, &host->i_i
633 pr_warn("aops:%ps invalid inod
634 return;
635 }
636
637 if (!dentry_first) {
638 pr_warn("aops:%ps ino:%lx\n",
639 return;
640 }
641
642 dentry_ptr = container_of(dentry_first
643 if (get_kernel_nofault(dentry, dentry_
644 !dentry.d_parent || !dentry.d_name
645 pr_warn("aops:%ps ino:%lx inva
646 a_ops, ino, de
647 return;
648 }
649
650 if (strncpy_from_kernel_nofault(fname,
651 strscpy(fname, "<invalid>");
652 /*
653 * Even if strncpy_from_kernel_nofault
654 * the fname could be unreliable
655 */
656 pr_warn("aops:%ps ino:%lx dentry name(
657 a_ops, ino, fname);
658 }
659
660 void clear_inode(struct inode *inode)
661 {
662 /*
663 * We have to cycle the i_pages lock h
664 * process of removing the last page (
665 * and we must not free the mapping un
666 */
667 xa_lock_irq(&inode->i_data.i_pages);
668 BUG_ON(inode->i_data.nrpages);
669 /*
670 * Almost always, mapping_empty(&inode
671 * two known and long-standing ways in
672 * (when deep radix-tree node allocati
673 * collapse_file() failed). Until thos
674 * or a cleanup function is called her
675 * nor even WARN_ON(!mapping_empty).
676 */
677 xa_unlock_irq(&inode->i_data.i_pages);
678 BUG_ON(!list_empty(&inode->i_data.i_pr
679 BUG_ON(!(inode->i_state & I_FREEING));
680 BUG_ON(inode->i_state & I_CLEAR);
681 BUG_ON(!list_empty(&inode->i_wb_list))
682 /* don't need i_lock here, no concurre
683 inode->i_state = I_FREEING | I_CLEAR;
684 }
685 EXPORT_SYMBOL(clear_inode);
686
687 /*
688 * Free the inode passed in, removing it from
689 * to. We remove any pages still attached to t
690 * is still in progress before finally destroy
691 *
692 * An inode must already be marked I_FREEING s
693 * moved back onto lists if we race with other
694 * (e.g. writeback_single_inode). The caller i
695 *
696 * An inode must already be removed from the L
697 * the cache. This should occur atomically wit
698 * flag, so no inodes here should ever be on t
699 */
700 static void evict(struct inode *inode)
701 {
702 const struct super_operations *op = in
703
704 BUG_ON(!(inode->i_state & I_FREEING));
705 BUG_ON(!list_empty(&inode->i_lru));
706
707 if (!list_empty(&inode->i_io_list))
708 inode_io_list_del(inode);
709
710 inode_sb_list_del(inode);
711
712 spin_lock(&inode->i_lock);
713 inode_wait_for_lru_isolating(inode);
714
715 /*
716 * Wait for flusher thread to be done
717 * does not start destroying it while
718 * the inode has I_FREEING set, flushe
719 * the inode. We just have to wait fo
720 */
721 inode_wait_for_writeback(inode);
722 spin_unlock(&inode->i_lock);
723
724 if (op->evict_inode) {
725 op->evict_inode(inode);
726 } else {
727 truncate_inode_pages_final(&in
728 clear_inode(inode);
729 }
730 if (S_ISCHR(inode->i_mode) && inode->i
731 cd_forget(inode);
732
733 remove_inode_hash(inode);
734
735 /*
736 * Wake up waiters in __wait_on_freein
737 *
738 * Lockless hash lookup may end up fin
739 * it above, but only lock it *after*
740 * In this case the potential waiter c
741 *
742 * The inode being unhashed after the
743 * used as an indicator whether blocki
744 */
745 spin_lock(&inode->i_lock);
746 /*
747 * Pairs with the barrier in prepare_t
748 * ___wait_var_event() either sees the
749 * waitqueue_active() check in wake_up
750 */
751 smp_mb();
752 inode_wake_up_bit(inode, __I_NEW);
753 BUG_ON(inode->i_state != (I_FREEING |
754 spin_unlock(&inode->i_lock);
755
756 destroy_inode(inode);
757 }
758
759 /*
760 * dispose_list - dispose of the contents of a
761 * @head: the head of the list to free
762 *
763 * Dispose-list gets a local list with local i
764 * need to worry about list corruption and SMP
765 */
766 static void dispose_list(struct list_head *hea
767 {
768 while (!list_empty(head)) {
769 struct inode *inode;
770
771 inode = list_first_entry(head,
772 list_del_init(&inode->i_lru);
773
774 evict(inode);
775 cond_resched();
776 }
777 }
778
779 /**
780 * evict_inodes - evict all evictable inodes f
781 * @sb: superblock to operate on
782 *
783 * Make sure that no inodes with zero refcount
784 * called by superblock shutdown after having
785 * so any inode reaching zero refcount during
786 * be immediately evicted.
787 */
788 void evict_inodes(struct super_block *sb)
789 {
790 struct inode *inode, *next;
791 LIST_HEAD(dispose);
792
793 again:
794 spin_lock(&sb->s_inode_list_lock);
795 list_for_each_entry_safe(inode, next,
796 if (atomic_read(&inode->i_coun
797 continue;
798
799 spin_lock(&inode->i_lock);
800 if (atomic_read(&inode->i_coun
801 spin_unlock(&inode->i_
802 continue;
803 }
804 if (inode->i_state & (I_NEW |
805 spin_unlock(&inode->i_
806 continue;
807 }
808
809 inode->i_state |= I_FREEING;
810 inode_lru_list_del(inode);
811 spin_unlock(&inode->i_lock);
812 list_add(&inode->i_lru, &dispo
813
814 /*
815 * We can have a ton of inodes
816 * enough memory, check to see
817 * bit so we don't livelock.
818 */
819 if (need_resched()) {
820 spin_unlock(&sb->s_ino
821 cond_resched();
822 dispose_list(&dispose)
823 goto again;
824 }
825 }
826 spin_unlock(&sb->s_inode_list_lock);
827
828 dispose_list(&dispose);
829 }
830 EXPORT_SYMBOL_GPL(evict_inodes);
831
832 /**
833 * invalidate_inodes - attempt to free all
834 * @sb: superblock to operate on
835 *
836 * Attempts to free all inodes (including dirt
837 */
838 void invalidate_inodes(struct super_block *sb)
839 {
840 struct inode *inode, *next;
841 LIST_HEAD(dispose);
842
843 again:
844 spin_lock(&sb->s_inode_list_lock);
845 list_for_each_entry_safe(inode, next,
846 spin_lock(&inode->i_lock);
847 if (inode->i_state & (I_NEW |
848 spin_unlock(&inode->i_
849 continue;
850 }
851 if (atomic_read(&inode->i_coun
852 spin_unlock(&inode->i_
853 continue;
854 }
855
856 inode->i_state |= I_FREEING;
857 inode_lru_list_del(inode);
858 spin_unlock(&inode->i_lock);
859 list_add(&inode->i_lru, &dispo
860 if (need_resched()) {
861 spin_unlock(&sb->s_ino
862 cond_resched();
863 dispose_list(&dispose)
864 goto again;
865 }
866 }
867 spin_unlock(&sb->s_inode_list_lock);
868
869 dispose_list(&dispose);
870 }
871
872 /*
873 * Isolate the inode from the LRU in preparati
874 *
875 * If the inode has the I_REFERENCED flag set,
876 * used recently - the flag is set in iput_fin
877 * inode, clear the flag and move it to the ba
878 * pass through the LRU before it gets reclaim
879 * the fact we are doing lazy LRU updates to m
880 * LRU does not have strict ordering. Hence we
881 * with this flag set because they are the ino
882 */
883 static enum lru_status inode_lru_isolate(struc
884 struct list_lru_one *lru, spin
885 {
886 struct list_head *freeable = arg;
887 struct inode *inode = container_of(
888
889 /*
890 * We are inverting the lru lock/inode
891 * trylock. If we fail to get the lock
892 */
893 if (!spin_trylock(&inode->i_lock))
894 return LRU_SKIP;
895
896 /*
897 * Inodes can get referenced, redirtie
898 * they're already on the LRU, and thi
899 * unreclaimable for a while. Remove t
900 * sync, or the last page cache deleti
901 */
902 if (atomic_read(&inode->i_count) ||
903 (inode->i_state & ~I_REFERENCED) |
904 !mapping_shrinkable(&inode->i_data
905 list_lru_isolate(lru, &inode->
906 spin_unlock(&inode->i_lock);
907 this_cpu_dec(nr_unused);
908 return LRU_REMOVED;
909 }
910
911 /* Recently referenced inodes get one
912 if (inode->i_state & I_REFERENCED) {
913 inode->i_state &= ~I_REFERENCE
914 spin_unlock(&inode->i_lock);
915 return LRU_ROTATE;
916 }
917
918 /*
919 * On highmem systems, mapping_shrinka
920 * page cache in order to free up stru
921 * be under pressure before the cache
922 */
923 if (inode_has_buffers(inode) || !mappi
924 inode_pin_lru_isolating(inode)
925 spin_unlock(&inode->i_lock);
926 spin_unlock(lru_lock);
927 if (remove_inode_buffers(inode
928 unsigned long reap;
929 reap = invalidate_mapp
930 if (current_is_kswapd(
931 __count_vm_eve
932 else
933 __count_vm_eve
934 mm_account_reclaimed_p
935 }
936 inode_unpin_lru_isolating(inod
937 spin_lock(lru_lock);
938 return LRU_RETRY;
939 }
940
941 WARN_ON(inode->i_state & I_NEW);
942 inode->i_state |= I_FREEING;
943 list_lru_isolate_move(lru, &inode->i_l
944 spin_unlock(&inode->i_lock);
945
946 this_cpu_dec(nr_unused);
947 return LRU_REMOVED;
948 }
949
950 /*
951 * Walk the superblock inode LRU for freeable
952 * This is called from the superblock shrinker
953 * to trim from the LRU. Inodes to be freed ar
954 * then are freed outside inode_lock by dispos
955 */
956 long prune_icache_sb(struct super_block *sb, s
957 {
958 LIST_HEAD(freeable);
959 long freed;
960
961 freed = list_lru_shrink_walk(&sb->s_in
962 inode_lru
963 dispose_list(&freeable);
964 return freed;
965 }
966
967 static void __wait_on_freeing_inode(struct ino
968 /*
969 * Called with the inode lock held.
970 */
971 static struct inode *find_inode(struct super_b
972 struct hlist_h
973 int (*test)(st
974 void *data, bo
975 {
976 struct inode *inode = NULL;
977
978 if (is_inode_hash_locked)
979 lockdep_assert_held(&inode_has
980 else
981 lockdep_assert_not_held(&inode
982
983 rcu_read_lock();
984 repeat:
985 hlist_for_each_entry_rcu(inode, head,
986 if (inode->i_sb != sb)
987 continue;
988 if (!test(inode, data))
989 continue;
990 spin_lock(&inode->i_lock);
991 if (inode->i_state & (I_FREEIN
992 __wait_on_freeing_inod
993 goto repeat;
994 }
995 if (unlikely(inode->i_state &
996 spin_unlock(&inode->i_
997 rcu_read_unlock();
998 return ERR_PTR(-ESTALE
999 }
1000 __iget(inode);
1001 spin_unlock(&inode->i_lock);
1002 rcu_read_unlock();
1003 return inode;
1004 }
1005 rcu_read_unlock();
1006 return NULL;
1007 }
1008
1009 /*
1010 * find_inode_fast is the fast path version o
1011 * iget_locked for details.
1012 */
1013 static struct inode *find_inode_fast(struct s
1014 struct hlist_
1015 bool is_inode
1016 {
1017 struct inode *inode = NULL;
1018
1019 if (is_inode_hash_locked)
1020 lockdep_assert_held(&inode_ha
1021 else
1022 lockdep_assert_not_held(&inod
1023
1024 rcu_read_lock();
1025 repeat:
1026 hlist_for_each_entry_rcu(inode, head,
1027 if (inode->i_ino != ino)
1028 continue;
1029 if (inode->i_sb != sb)
1030 continue;
1031 spin_lock(&inode->i_lock);
1032 if (inode->i_state & (I_FREEI
1033 __wait_on_freeing_ino
1034 goto repeat;
1035 }
1036 if (unlikely(inode->i_state &
1037 spin_unlock(&inode->i
1038 rcu_read_unlock();
1039 return ERR_PTR(-ESTAL
1040 }
1041 __iget(inode);
1042 spin_unlock(&inode->i_lock);
1043 rcu_read_unlock();
1044 return inode;
1045 }
1046 rcu_read_unlock();
1047 return NULL;
1048 }
1049
1050 /*
1051 * Each cpu owns a range of LAST_INO_BATCH nu
1052 * 'shared_last_ino' is dirtied only once out
1053 * to renew the exhausted range.
1054 *
1055 * This does not significantly increase overf
1056 * consume at most LAST_INO_BATCH-1 unused in
1057 * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 409
1058 * 2^32 range, and is a worst-case. Even a 50
1059 * overflow rate by 2x, which does not seem t
1060 *
1061 * On a 32bit, non LFS stat() call, glibc wil
1062 * error if st_ino won't fit in target struct
1063 * here to attempt to avoid that.
1064 */
1065 #define LAST_INO_BATCH 1024
1066 static DEFINE_PER_CPU(unsigned int, last_ino)
1067
1068 unsigned int get_next_ino(void)
1069 {
1070 unsigned int *p = &get_cpu_var(last_i
1071 unsigned int res = *p;
1072
1073 #ifdef CONFIG_SMP
1074 if (unlikely((res & (LAST_INO_BATCH-1
1075 static atomic_t shared_last_i
1076 int next = atomic_add_return(
1077
1078 res = next - LAST_INO_BATCH;
1079 }
1080 #endif
1081
1082 res++;
1083 /* get_next_ino should not provide a
1084 if (unlikely(!res))
1085 res++;
1086 *p = res;
1087 put_cpu_var(last_ino);
1088 return res;
1089 }
1090 EXPORT_SYMBOL(get_next_ino);
1091
1092 /**
1093 * new_inode_pseudo - obtain an i
1094 * @sb: superblock
1095 *
1096 * Allocates a new inode for given super
1097 * Inode wont be chained in superblock s
1098 * This means :
1099 * - fs can't be unmount
1100 * - quotas, fsnotify, writeback can't w
1101 */
1102 struct inode *new_inode_pseudo(struct super_b
1103 {
1104 return alloc_inode(sb);
1105 }
1106
1107 /**
1108 * new_inode - obtain an inode
1109 * @sb: superblock
1110 *
1111 * Allocates a new inode for given super
1112 * for allocations related to inode->i_m
1113 * If HIGHMEM pages are unsuitable or it
1114 * for the page cache are not reclaimabl
1115 * mapping_set_gfp_mask() must be called
1116 * newly created inode's mapping
1117 *
1118 */
1119 struct inode *new_inode(struct super_block *s
1120 {
1121 struct inode *inode;
1122
1123 inode = new_inode_pseudo(sb);
1124 if (inode)
1125 inode_sb_list_add(inode);
1126 return inode;
1127 }
1128 EXPORT_SYMBOL(new_inode);
1129
1130 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1131 void lockdep_annotate_inode_mutex_key(struct
1132 {
1133 if (S_ISDIR(inode->i_mode)) {
1134 struct file_system_type *type
1135
1136 /* Set new key only if filesy
1137 if (lockdep_match_class(&inod
1138 /*
1139 * ensure nobody is a
1140 */
1141 // mutex_destroy(&ino
1142 init_rwsem(&inode->i_
1143 lockdep_set_class(&in
1144 &ty
1145 }
1146 }
1147 }
1148 EXPORT_SYMBOL(lockdep_annotate_inode_mutex_ke
1149 #endif
1150
1151 /**
1152 * unlock_new_inode - clear the I_NEW state a
1153 * @inode: new inode to unlock
1154 *
1155 * Called when the inode is fully initialised
1156 * inode and wake up anyone waiting for the i
1157 */
1158 void unlock_new_inode(struct inode *inode)
1159 {
1160 lockdep_annotate_inode_mutex_key(inod
1161 spin_lock(&inode->i_lock);
1162 WARN_ON(!(inode->i_state & I_NEW));
1163 inode->i_state &= ~I_NEW & ~I_CREATIN
1164 /*
1165 * Pairs with the barrier in prepare_
1166 * ___wait_var_event() either sees th
1167 * waitqueue_active() check in wake_u
1168 */
1169 smp_mb();
1170 inode_wake_up_bit(inode, __I_NEW);
1171 spin_unlock(&inode->i_lock);
1172 }
1173 EXPORT_SYMBOL(unlock_new_inode);
1174
1175 void discard_new_inode(struct inode *inode)
1176 {
1177 lockdep_annotate_inode_mutex_key(inod
1178 spin_lock(&inode->i_lock);
1179 WARN_ON(!(inode->i_state & I_NEW));
1180 inode->i_state &= ~I_NEW;
1181 /*
1182 * Pairs with the barrier in prepare_
1183 * ___wait_var_event() either sees th
1184 * waitqueue_active() check in wake_u
1185 */
1186 smp_mb();
1187 inode_wake_up_bit(inode, __I_NEW);
1188 spin_unlock(&inode->i_lock);
1189 iput(inode);
1190 }
1191 EXPORT_SYMBOL(discard_new_inode);
1192
1193 /**
1194 * lock_two_nondirectories - take two i_mutex
1195 *
1196 * Lock any non-NULL argument. Passed objects
1197 * Zero, one or two objects may be locked by
1198 *
1199 * @inode1: first inode to lock
1200 * @inode2: second inode to lock
1201 */
1202 void lock_two_nondirectories(struct inode *in
1203 {
1204 if (inode1)
1205 WARN_ON_ONCE(S_ISDIR(inode1->
1206 if (inode2)
1207 WARN_ON_ONCE(S_ISDIR(inode2->
1208 if (inode1 > inode2)
1209 swap(inode1, inode2);
1210 if (inode1)
1211 inode_lock(inode1);
1212 if (inode2 && inode2 != inode1)
1213 inode_lock_nested(inode2, I_M
1214 }
1215 EXPORT_SYMBOL(lock_two_nondirectories);
1216
1217 /**
1218 * unlock_two_nondirectories - release locks
1219 * @inode1: first inode to unlock
1220 * @inode2: second inode to unlock
1221 */
1222 void unlock_two_nondirectories(struct inode *
1223 {
1224 if (inode1) {
1225 WARN_ON_ONCE(S_ISDIR(inode1->
1226 inode_unlock(inode1);
1227 }
1228 if (inode2 && inode2 != inode1) {
1229 WARN_ON_ONCE(S_ISDIR(inode2->
1230 inode_unlock(inode2);
1231 }
1232 }
1233 EXPORT_SYMBOL(unlock_two_nondirectories);
1234
1235 /**
1236 * inode_insert5 - obtain an inode from a mou
1237 * @inode: pre-allocated inode to use fo
1238 * @hashval: hash value (usually inode num
1239 * @test: callback used for comparisons
1240 * @set: callback used to initialize a
1241 * @data: opaque data pointer to pass t
1242 *
1243 * Search for the inode specified by @hashval
1244 * and if present it is return it with an inc
1245 * a variant of iget5_locked() for callers th
1246 * allocation of inode.
1247 *
1248 * If the inode is not in cache, insert the p
1249 * return it locked, hashed, and with the I_N
1250 * to fill it in before unlocking it via unlo
1251 *
1252 * Note both @test and @set are called with t
1253 * sleep.
1254 */
1255 struct inode *inode_insert5(struct inode *ino
1256 int (*test)(struc
1257 int (*set)(struct
1258 {
1259 struct hlist_head *head = inode_hasht
1260 struct inode *old;
1261
1262 again:
1263 spin_lock(&inode_hash_lock);
1264 old = find_inode(inode->i_sb, head, t
1265 if (unlikely(old)) {
1266 /*
1267 * Uhhuh, somebody else creat
1268 * Use the old inode instead
1269 */
1270 spin_unlock(&inode_hash_lock)
1271 if (IS_ERR(old))
1272 return NULL;
1273 wait_on_inode(old);
1274 if (unlikely(inode_unhashed(o
1275 iput(old);
1276 goto again;
1277 }
1278 return old;
1279 }
1280
1281 if (set && unlikely(set(inode, data))
1282 inode = NULL;
1283 goto unlock;
1284 }
1285
1286 /*
1287 * Return the locked inode with I_NEW
1288 * caller is responsible for filling
1289 */
1290 spin_lock(&inode->i_lock);
1291 inode->i_state |= I_NEW;
1292 hlist_add_head_rcu(&inode->i_hash, he
1293 spin_unlock(&inode->i_lock);
1294
1295 /*
1296 * Add inode to the sb list if it's n
1297 * point, so it should be safe to tes
1298 */
1299 if (list_empty(&inode->i_sb_list))
1300 inode_sb_list_add(inode);
1301 unlock:
1302 spin_unlock(&inode_hash_lock);
1303
1304 return inode;
1305 }
1306 EXPORT_SYMBOL(inode_insert5);
1307
1308 /**
1309 * iget5_locked - obtain an inode from a moun
1310 * @sb: super block of file system
1311 * @hashval: hash value (usually inode num
1312 * @test: callback used for comparisons
1313 * @set: callback used to initialize a
1314 * @data: opaque data pointer to pass t
1315 *
1316 * Search for the inode specified by @hashval
1317 * and if present it is return it with an inc
1318 * a generalized version of iget_locked() for
1319 * number is not sufficient for unique identi
1320 *
1321 * If the inode is not in cache, allocate a n
1322 * hashed, and with the I_NEW flag set. The f
1323 * before unlocking it via unlock_new_inode()
1324 *
1325 * Note both @test and @set are called with t
1326 * sleep.
1327 */
1328 struct inode *iget5_locked(struct super_block
1329 int (*test)(struct inode *, v
1330 int (*set)(struct inode *, vo
1331 {
1332 struct inode *inode = ilookup5(sb, ha
1333
1334 if (!inode) {
1335 struct inode *new = alloc_ino
1336
1337 if (new) {
1338 inode = inode_insert5
1339 if (unlikely(inode !=
1340 destroy_inode
1341 }
1342 }
1343 return inode;
1344 }
1345 EXPORT_SYMBOL(iget5_locked);
1346
1347 /**
1348 * iget5_locked_rcu - obtain an inode from a
1349 * @sb: super block of file system
1350 * @hashval: hash value (usually inode num
1351 * @test: callback used for comparisons
1352 * @set: callback used to initialize a
1353 * @data: opaque data pointer to pass t
1354 *
1355 * This is equivalent to iget5_locked, except
1356 * tolerate the inode not being stable, inclu
1357 */
1358 struct inode *iget5_locked_rcu(struct super_b
1359 int (*test)(struct inode *, v
1360 int (*set)(struct inode *, vo
1361 {
1362 struct hlist_head *head = inode_hasht
1363 struct inode *inode, *new;
1364
1365 again:
1366 inode = find_inode(sb, head, test, da
1367 if (inode) {
1368 if (IS_ERR(inode))
1369 return NULL;
1370 wait_on_inode(inode);
1371 if (unlikely(inode_unhashed(i
1372 iput(inode);
1373 goto again;
1374 }
1375 return inode;
1376 }
1377
1378 new = alloc_inode(sb);
1379 if (new) {
1380 inode = inode_insert5(new, ha
1381 if (unlikely(inode != new))
1382 destroy_inode(new);
1383 }
1384 return inode;
1385 }
1386 EXPORT_SYMBOL_GPL(iget5_locked_rcu);
1387
1388 /**
1389 * iget_locked - obtain an inode from a mount
1390 * @sb: super block of file system
1391 * @ino: inode number to get
1392 *
1393 * Search for the inode specified by @ino in
1394 * return it with an increased reference coun
1395 * where the inode number is sufficient for u
1396 *
1397 * If the inode is not in cache, allocate a n
1398 * hashed, and with the I_NEW flag set. The
1399 * before unlocking it via unlock_new_inode()
1400 */
1401 struct inode *iget_locked(struct super_block
1402 {
1403 struct hlist_head *head = inode_hasht
1404 struct inode *inode;
1405 again:
1406 inode = find_inode_fast(sb, head, ino
1407 if (inode) {
1408 if (IS_ERR(inode))
1409 return NULL;
1410 wait_on_inode(inode);
1411 if (unlikely(inode_unhashed(i
1412 iput(inode);
1413 goto again;
1414 }
1415 return inode;
1416 }
1417
1418 inode = alloc_inode(sb);
1419 if (inode) {
1420 struct inode *old;
1421
1422 spin_lock(&inode_hash_lock);
1423 /* We released the lock, so..
1424 old = find_inode_fast(sb, hea
1425 if (!old) {
1426 inode->i_ino = ino;
1427 spin_lock(&inode->i_l
1428 inode->i_state = I_NE
1429 hlist_add_head_rcu(&i
1430 spin_unlock(&inode->i
1431 inode_sb_list_add(ino
1432 spin_unlock(&inode_ha
1433
1434 /* Return the locked
1435 * caller is responsi
1436 */
1437 return inode;
1438 }
1439
1440 /*
1441 * Uhhuh, somebody else creat
1442 * us. Use the old inode inst
1443 * allocated.
1444 */
1445 spin_unlock(&inode_hash_lock)
1446 destroy_inode(inode);
1447 if (IS_ERR(old))
1448 return NULL;
1449 inode = old;
1450 wait_on_inode(inode);
1451 if (unlikely(inode_unhashed(i
1452 iput(inode);
1453 goto again;
1454 }
1455 }
1456 return inode;
1457 }
1458 EXPORT_SYMBOL(iget_locked);
1459
1460 /*
1461 * search the inode cache for a matching inod
1462 * If we find one, then the inode number we a
1463 * allocate is not unique and so we should no
1464 *
1465 * Returns 1 if the inode number is unique, 0
1466 */
1467 static int test_inode_iunique(struct super_bl
1468 {
1469 struct hlist_head *b = inode_hashtabl
1470 struct inode *inode;
1471
1472 hlist_for_each_entry_rcu(inode, b, i_
1473 if (inode->i_ino == ino && in
1474 return 0;
1475 }
1476 return 1;
1477 }
1478
1479 /**
1480 * iunique - get a unique inode number
1481 * @sb: superblock
1482 * @max_reserved: highest reserved inode
1483 *
1484 * Obtain an inode number that is unique
1485 * superblock. This is used by file syst
1486 * permanent inode numbering system. An
1487 * is higher than the reserved limit but
1488 *
1489 * BUGS:
1490 * With a large number of inodes live on
1491 * currently becomes quite slow.
1492 */
1493 ino_t iunique(struct super_block *sb, ino_t m
1494 {
1495 /*
1496 * On a 32bit, non LFS stat() call, g
1497 * error if st_ino won't fit in targe
1498 * here to attempt to avoid that.
1499 */
1500 static DEFINE_SPINLOCK(iunique_lock);
1501 static unsigned int counter;
1502 ino_t res;
1503
1504 rcu_read_lock();
1505 spin_lock(&iunique_lock);
1506 do {
1507 if (counter <= max_reserved)
1508 counter = max_reserve
1509 res = counter++;
1510 } while (!test_inode_iunique(sb, res)
1511 spin_unlock(&iunique_lock);
1512 rcu_read_unlock();
1513
1514 return res;
1515 }
1516 EXPORT_SYMBOL(iunique);
1517
1518 struct inode *igrab(struct inode *inode)
1519 {
1520 spin_lock(&inode->i_lock);
1521 if (!(inode->i_state & (I_FREEING|I_W
1522 __iget(inode);
1523 spin_unlock(&inode->i_lock);
1524 } else {
1525 spin_unlock(&inode->i_lock);
1526 /*
1527 * Handle the case where s_op
1528 * called yet, and somebody i
1529 * while the inode is getting
1530 */
1531 inode = NULL;
1532 }
1533 return inode;
1534 }
1535 EXPORT_SYMBOL(igrab);
1536
1537 /**
1538 * ilookup5_nowait - search for an inode in t
1539 * @sb: super block of file system to
1540 * @hashval: hash value (usually inode num
1541 * @test: callback used for comparisons
1542 * @data: opaque data pointer to pass t
1543 *
1544 * Search for the inode specified by @hashval
1545 * If the inode is in the cache, the inode is
1546 * reference count.
1547 *
1548 * Note: I_NEW is not waited upon so you have
1549 * with the returned inode. You probably sho
1550 *
1551 * Note2: @test is called with the inode_hash
1552 */
1553 struct inode *ilookup5_nowait(struct super_bl
1554 int (*test)(struct inode *, v
1555 {
1556 struct hlist_head *head = inode_hasht
1557 struct inode *inode;
1558
1559 spin_lock(&inode_hash_lock);
1560 inode = find_inode(sb, head, test, da
1561 spin_unlock(&inode_hash_lock);
1562
1563 return IS_ERR(inode) ? NULL : inode;
1564 }
1565 EXPORT_SYMBOL(ilookup5_nowait);
1566
1567 /**
1568 * ilookup5 - search for an inode in the inod
1569 * @sb: super block of file system to
1570 * @hashval: hash value (usually inode num
1571 * @test: callback used for comparisons
1572 * @data: opaque data pointer to pass t
1573 *
1574 * Search for the inode specified by @hashval
1575 * and if the inode is in the cache, return t
1576 * reference count. Waits on I_NEW before re
1577 * returned with an incremented reference cou
1578 *
1579 * This is a generalized version of ilookup()
1580 * inode number is not sufficient for unique
1581 *
1582 * Note: @test is called with the inode_hash_
1583 */
1584 struct inode *ilookup5(struct super_block *sb
1585 int (*test)(struct inode *, v
1586 {
1587 struct inode *inode;
1588 again:
1589 inode = ilookup5_nowait(sb, hashval,
1590 if (inode) {
1591 wait_on_inode(inode);
1592 if (unlikely(inode_unhashed(i
1593 iput(inode);
1594 goto again;
1595 }
1596 }
1597 return inode;
1598 }
1599 EXPORT_SYMBOL(ilookup5);
1600
1601 /**
1602 * ilookup - search for an inode in the inode
1603 * @sb: super block of file system to
1604 * @ino: inode number to search for
1605 *
1606 * Search for the inode @ino in the inode cac
1607 * cache, the inode is returned with an incre
1608 */
1609 struct inode *ilookup(struct super_block *sb,
1610 {
1611 struct hlist_head *head = inode_hasht
1612 struct inode *inode;
1613 again:
1614 inode = find_inode_fast(sb, head, ino
1615
1616 if (inode) {
1617 if (IS_ERR(inode))
1618 return NULL;
1619 wait_on_inode(inode);
1620 if (unlikely(inode_unhashed(i
1621 iput(inode);
1622 goto again;
1623 }
1624 }
1625 return inode;
1626 }
1627 EXPORT_SYMBOL(ilookup);
1628
1629 /**
1630 * find_inode_nowait - find an inode in the i
1631 * @sb: super block of file system to
1632 * @hashval: hash value (usually inode num
1633 * @match: callback used for comparisons
1634 * @data: opaque data pointer to pass t
1635 *
1636 * Search for the inode specified by @hashval
1637 * cache, where the helper function @match wi
1638 * does not match, 1 if the inode does match,
1639 * should be stopped. The @match function mu
1640 * taking the i_lock spin_lock and checking i
1641 * freed or being initialized, and incrementi
1642 * before returning 1. It also must not slee
1643 * the inode_hash_lock spinlock held.
1644 *
1645 * This is a even more generalized version of
1646 * function must never block --- find_inode()
1647 * __wait_on_freeing_inode() --- or when the
1648 * the reference count because the resulting
1649 * inode eviction. The tradeoff is that the
1650 * very carefully implemented.
1651 */
1652 struct inode *find_inode_nowait(struct super_
1653 unsigned long
1654 int (*match)(
1655
1656 void *data)
1657 {
1658 struct hlist_head *head = inode_hasht
1659 struct inode *inode, *ret_inode = NUL
1660 int mval;
1661
1662 spin_lock(&inode_hash_lock);
1663 hlist_for_each_entry(inode, head, i_h
1664 if (inode->i_sb != sb)
1665 continue;
1666 mval = match(inode, hashval,
1667 if (mval == 0)
1668 continue;
1669 if (mval == 1)
1670 ret_inode = inode;
1671 goto out;
1672 }
1673 out:
1674 spin_unlock(&inode_hash_lock);
1675 return ret_inode;
1676 }
1677 EXPORT_SYMBOL(find_inode_nowait);
1678
1679 /**
1680 * find_inode_rcu - find an inode in the inod
1681 * @sb: Super block of file system to
1682 * @hashval: Key to hash
1683 * @test: Function to test match on an
1684 * @data: Data for test function
1685 *
1686 * Search for the inode specified by @hashval
1687 * where the helper function @test will retur
1688 * and 1 if it does. The @test function must
1689 * i_lock spin_lock and checking i_state for
1690 * initialized.
1691 *
1692 * If successful, this will return the inode
1693 * returned 1 and NULL otherwise.
1694 *
1695 * The @test function is not permitted to tak
1696 * It is also not permitted to sleep.
1697 *
1698 * The caller must hold the RCU read lock.
1699 */
1700 struct inode *find_inode_rcu(struct super_blo
1701 int (*test)(stru
1702 {
1703 struct hlist_head *head = inode_hasht
1704 struct inode *inode;
1705
1706 RCU_LOCKDEP_WARN(!rcu_read_lock_held(
1707 "suspicious find_ino
1708
1709 hlist_for_each_entry_rcu(inode, head,
1710 if (inode->i_sb == sb &&
1711 !(READ_ONCE(inode->i_stat
1712 test(inode, data))
1713 return inode;
1714 }
1715 return NULL;
1716 }
1717 EXPORT_SYMBOL(find_inode_rcu);
1718
1719 /**
1720 * find_inode_by_ino_rcu - Find an inode in t
1721 * @sb: Super block of file system to
1722 * @ino: The inode number to match
1723 *
1724 * Search for the inode specified by @hashval
1725 * where the helper function @test will retur
1726 * and 1 if it does. The @test function must
1727 * i_lock spin_lock and checking i_state for
1728 * initialized.
1729 *
1730 * If successful, this will return the inode
1731 * returned 1 and NULL otherwise.
1732 *
1733 * The @test function is not permitted to tak
1734 * It is also not permitted to sleep.
1735 *
1736 * The caller must hold the RCU read lock.
1737 */
1738 struct inode *find_inode_by_ino_rcu(struct su
1739 unsigned
1740 {
1741 struct hlist_head *head = inode_hasht
1742 struct inode *inode;
1743
1744 RCU_LOCKDEP_WARN(!rcu_read_lock_held(
1745 "suspicious find_ino
1746
1747 hlist_for_each_entry_rcu(inode, head,
1748 if (inode->i_ino == ino &&
1749 inode->i_sb == sb &&
1750 !(READ_ONCE(inode->i_stat
1751 return inode;
1752 }
1753 return NULL;
1754 }
1755 EXPORT_SYMBOL(find_inode_by_ino_rcu);
1756
1757 int insert_inode_locked(struct inode *inode)
1758 {
1759 struct super_block *sb = inode->i_sb;
1760 ino_t ino = inode->i_ino;
1761 struct hlist_head *head = inode_hasht
1762
1763 while (1) {
1764 struct inode *old = NULL;
1765 spin_lock(&inode_hash_lock);
1766 hlist_for_each_entry(old, hea
1767 if (old->i_ino != ino
1768 continue;
1769 if (old->i_sb != sb)
1770 continue;
1771 spin_lock(&old->i_loc
1772 if (old->i_state & (I
1773 spin_unlock(&
1774 continue;
1775 }
1776 break;
1777 }
1778 if (likely(!old)) {
1779 spin_lock(&inode->i_l
1780 inode->i_state |= I_N
1781 hlist_add_head_rcu(&i
1782 spin_unlock(&inode->i
1783 spin_unlock(&inode_ha
1784 return 0;
1785 }
1786 if (unlikely(old->i_state & I
1787 spin_unlock(&old->i_l
1788 spin_unlock(&inode_ha
1789 return -EBUSY;
1790 }
1791 __iget(old);
1792 spin_unlock(&old->i_lock);
1793 spin_unlock(&inode_hash_lock)
1794 wait_on_inode(old);
1795 if (unlikely(!inode_unhashed(
1796 iput(old);
1797 return -EBUSY;
1798 }
1799 iput(old);
1800 }
1801 }
1802 EXPORT_SYMBOL(insert_inode_locked);
1803
1804 int insert_inode_locked4(struct inode *inode,
1805 int (*test)(struct inode *, v
1806 {
1807 struct inode *old;
1808
1809 inode->i_state |= I_CREATING;
1810 old = inode_insert5(inode, hashval, t
1811
1812 if (old != inode) {
1813 iput(old);
1814 return -EBUSY;
1815 }
1816 return 0;
1817 }
1818 EXPORT_SYMBOL(insert_inode_locked4);
1819
1820
1821 int generic_delete_inode(struct inode *inode)
1822 {
1823 return 1;
1824 }
1825 EXPORT_SYMBOL(generic_delete_inode);
1826
1827 /*
1828 * Called when we're dropping the last refere
1829 * to an inode.
1830 *
1831 * Call the FS "drop_inode()" function, defau
1832 * the legacy UNIX filesystem behaviour. If
1833 * us to evict inode, do so. Otherwise, reta
1834 * in cache if fs is alive, sync and evict if
1835 * shutting down.
1836 */
1837 static void iput_final(struct inode *inode)
1838 {
1839 struct super_block *sb = inode->i_sb;
1840 const struct super_operations *op = i
1841 unsigned long state;
1842 int drop;
1843
1844 WARN_ON(inode->i_state & I_NEW);
1845
1846 if (op->drop_inode)
1847 drop = op->drop_inode(inode);
1848 else
1849 drop = generic_drop_inode(ino
1850
1851 if (!drop &&
1852 !(inode->i_state & I_DONTCACHE) &
1853 (sb->s_flags & SB_ACTIVE)) {
1854 __inode_add_lru(inode, true);
1855 spin_unlock(&inode->i_lock);
1856 return;
1857 }
1858
1859 state = inode->i_state;
1860 if (!drop) {
1861 WRITE_ONCE(inode->i_state, st
1862 spin_unlock(&inode->i_lock);
1863
1864 write_inode_now(inode, 1);
1865
1866 spin_lock(&inode->i_lock);
1867 state = inode->i_state;
1868 WARN_ON(state & I_NEW);
1869 state &= ~I_WILL_FREE;
1870 }
1871
1872 WRITE_ONCE(inode->i_state, state | I_
1873 if (!list_empty(&inode->i_lru))
1874 inode_lru_list_del(inode);
1875 spin_unlock(&inode->i_lock);
1876
1877 evict(inode);
1878 }
1879
1880 /**
1881 * iput - put an inode
1882 * @inode: inode to put
1883 *
1884 * Puts an inode, dropping its usage cou
1885 * zero, the inode is then freed and may
1886 *
1887 * Consequently, iput() can sleep.
1888 */
1889 void iput(struct inode *inode)
1890 {
1891 if (!inode)
1892 return;
1893 BUG_ON(inode->i_state & I_CLEAR);
1894 retry:
1895 if (atomic_dec_and_lock(&inode->i_cou
1896 if (inode->i_nlink && (inode-
1897 atomic_inc(&inode->i_
1898 spin_unlock(&inode->i
1899 trace_writeback_lazyt
1900 mark_inode_dirty_sync
1901 goto retry;
1902 }
1903 iput_final(inode);
1904 }
1905 }
1906 EXPORT_SYMBOL(iput);
1907
1908 #ifdef CONFIG_BLOCK
1909 /**
1910 * bmap - find a block number in a fi
1911 * @inode: inode owning the block numbe
1912 * @block: pointer containing the block
1913 *
1914 * Replaces the value in ``*block`` with
1915 * corresponding to the requested block
1916 * That is, asked for block 4 of inode 1
1917 * 4 in ``*block``, with disk block rela
1918 * block of the file.
1919 *
1920 * Returns -EINVAL in case of error, 0 o
1921 * hole, returns 0 and ``*block`` is als
1922 */
1923 int bmap(struct inode *inode, sector_t *block
1924 {
1925 if (!inode->i_mapping->a_ops->bmap)
1926 return -EINVAL;
1927
1928 *block = inode->i_mapping->a_ops->bma
1929 return 0;
1930 }
1931 EXPORT_SYMBOL(bmap);
1932 #endif
1933
1934 /*
1935 * With relative atime, only update atime if
1936 * earlier than or equal to either the ctime
1937 * or if at least a day has passed since the
1938 */
1939 static bool relatime_need_update(struct vfsmo
1940 struct timespec6
1941 {
1942 struct timespec64 atime, mtime, ctime
1943
1944 if (!(mnt->mnt_flags & MNT_RELATIME))
1945 return true;
1946 /*
1947 * Is mtime younger than or equal to
1948 */
1949 atime = inode_get_atime(inode);
1950 mtime = inode_get_mtime(inode);
1951 if (timespec64_compare(&mtime, &atime
1952 return true;
1953 /*
1954 * Is ctime younger than or equal to
1955 */
1956 ctime = inode_get_ctime(inode);
1957 if (timespec64_compare(&ctime, &atime
1958 return true;
1959
1960 /*
1961 * Is the previous atime value older
1962 * update atime:
1963 */
1964 if ((long)(now.tv_sec - atime.tv_sec)
1965 return true;
1966 /*
1967 * Good, we can skip the atime update
1968 */
1969 return false;
1970 }
1971
1972 /**
1973 * inode_update_timestamps - update the times
1974 * @inode: inode to be updated
1975 * @flags: S_* flags that needed to be update
1976 *
1977 * The update_time function is called when an
1978 * updated for a read or write operation. Thi
1979 * actual timestamps. It's up to the caller t
1980 * dirty appropriately.
1981 *
1982 * In the case where any of S_MTIME, S_CTIME,
1983 * attempt to update all three of them. S_ATI
1984 * independently of the rest.
1985 *
1986 * Returns a set of S_* flags indicating whic
1987 */
1988 int inode_update_timestamps(struct inode *ino
1989 {
1990 int updated = 0;
1991 struct timespec64 now;
1992
1993 if (flags & (S_MTIME|S_CTIME|S_VERSIO
1994 struct timespec64 ctime = ino
1995 struct timespec64 mtime = ino
1996
1997 now = inode_set_ctime_current
1998 if (!timespec64_equal(&now, &
1999 updated |= S_CTIME;
2000 if (!timespec64_equal(&now, &
2001 inode_set_mtime_to_ts
2002 updated |= S_MTIME;
2003 }
2004 if (IS_I_VERSION(inode) && in
2005 updated |= S_VERSION;
2006 } else {
2007 now = current_time(inode);
2008 }
2009
2010 if (flags & S_ATIME) {
2011 struct timespec64 atime = ino
2012
2013 if (!timespec64_equal(&now, &
2014 inode_set_atime_to_ts
2015 updated |= S_ATIME;
2016 }
2017 }
2018 return updated;
2019 }
2020 EXPORT_SYMBOL(inode_update_timestamps);
2021
2022 /**
2023 * generic_update_time - update the timestamp
2024 * @inode: inode to be updated
2025 * @flags: S_* flags that needed to be update
2026 *
2027 * The update_time function is called when an
2028 * updated for a read or write operation. In
2029 * or S_VERSION need to be updated we attempt
2030 * updates can be handled done independently
2031 *
2032 * Returns a S_* mask indicating which fields
2033 */
2034 int generic_update_time(struct inode *inode,
2035 {
2036 int updated = inode_update_timestamps
2037 int dirty_flags = 0;
2038
2039 if (updated & (S_ATIME|S_MTIME|S_CTIM
2040 dirty_flags = inode->i_sb->s_
2041 if (updated & S_VERSION)
2042 dirty_flags |= I_DIRTY_SYNC;
2043 __mark_inode_dirty(inode, dirty_flags
2044 return updated;
2045 }
2046 EXPORT_SYMBOL(generic_update_time);
2047
2048 /*
2049 * This does the actual work of updating an i
2050 * had called mnt_want_write() before calling
2051 */
2052 int inode_update_time(struct inode *inode, in
2053 {
2054 if (inode->i_op->update_time)
2055 return inode->i_op->update_ti
2056 generic_update_time(inode, flags);
2057 return 0;
2058 }
2059 EXPORT_SYMBOL(inode_update_time);
2060
2061 /**
2062 * atime_needs_update - updat
2063 * @path: the &struct path to update
2064 * @inode: inode to update
2065 *
2066 * Update the accessed time on an inode
2067 * This function automatically handles r
2068 * as well as the "noatime" flag and ino
2069 */
2070 bool atime_needs_update(const struct path *pa
2071 {
2072 struct vfsmount *mnt = path->mnt;
2073 struct timespec64 now, atime;
2074
2075 if (inode->i_flags & S_NOATIME)
2076 return false;
2077
2078 /* Atime updates will likely cause i_
2079 * back improprely if their true valu
2080 */
2081 if (HAS_UNMAPPED_ID(mnt_idmap(mnt), i
2082 return false;
2083
2084 if (IS_NOATIME(inode))
2085 return false;
2086 if ((inode->i_sb->s_flags & SB_NODIRA
2087 return false;
2088
2089 if (mnt->mnt_flags & MNT_NOATIME)
2090 return false;
2091 if ((mnt->mnt_flags & MNT_NODIRATIME)
2092 return false;
2093
2094 now = current_time(inode);
2095
2096 if (!relatime_need_update(mnt, inode,
2097 return false;
2098
2099 atime = inode_get_atime(inode);
2100 if (timespec64_equal(&atime, &now))
2101 return false;
2102
2103 return true;
2104 }
2105
2106 void touch_atime(const struct path *path)
2107 {
2108 struct vfsmount *mnt = path->mnt;
2109 struct inode *inode = d_inode(path->d
2110
2111 if (!atime_needs_update(path, inode))
2112 return;
2113
2114 if (!sb_start_write_trylock(inode->i_
2115 return;
2116
2117 if (mnt_get_write_access(mnt) != 0)
2118 goto skip_update;
2119 /*
2120 * File systems can error out when up
2121 * allocate new space to modify an in
2122 * Btrfs), but since we touch atime w
2123 * really don't care if we failed to
2124 * so just ignore the return value.
2125 * We may also fail on filesystems th
2126 * of the fs read only, e.g. subvolum
2127 */
2128 inode_update_time(inode, S_ATIME);
2129 mnt_put_write_access(mnt);
2130 skip_update:
2131 sb_end_write(inode->i_sb);
2132 }
2133 EXPORT_SYMBOL(touch_atime);
2134
2135 /*
2136 * Return mask of changes for notify_change()
2137 * response to write or truncate. Return 0 if
2138 * Negative value on error (change should be
2139 */
2140 int dentry_needs_remove_privs(struct mnt_idma
2141 struct dentry *
2142 {
2143 struct inode *inode = d_inode(dentry)
2144 int mask = 0;
2145 int ret;
2146
2147 if (IS_NOSEC(inode))
2148 return 0;
2149
2150 mask = setattr_should_drop_suidgid(id
2151 ret = security_inode_need_killpriv(de
2152 if (ret < 0)
2153 return ret;
2154 if (ret)
2155 mask |= ATTR_KILL_PRIV;
2156 return mask;
2157 }
2158
2159 static int __remove_privs(struct mnt_idmap *i
2160 struct dentry *dent
2161 {
2162 struct iattr newattrs;
2163
2164 newattrs.ia_valid = ATTR_FORCE | kill
2165 /*
2166 * Note we call this on write, so not
2167 * encounter any conflicting delegati
2168 */
2169 return notify_change(idmap, dentry, &
2170 }
2171
2172 int file_remove_privs_flags(struct file *file
2173 {
2174 struct dentry *dentry = file_dentry(f
2175 struct inode *inode = file_inode(file
2176 int error = 0;
2177 int kill;
2178
2179 if (IS_NOSEC(inode) || !S_ISREG(inode
2180 return 0;
2181
2182 kill = dentry_needs_remove_privs(file
2183 if (kill < 0)
2184 return kill;
2185
2186 if (kill) {
2187 if (flags & IOCB_NOWAIT)
2188 return -EAGAIN;
2189
2190 error = __remove_privs(file_m
2191 }
2192
2193 if (!error)
2194 inode_has_no_xattr(inode);
2195 return error;
2196 }
2197 EXPORT_SYMBOL_GPL(file_remove_privs_flags);
2198
2199 /**
2200 * file_remove_privs - remove special file pr
2201 * @file: file to remove privileges from
2202 *
2203 * When file is modified by a write or trunca
2204 * file privileges are removed.
2205 *
2206 * Return: 0 on success, negative errno on fa
2207 */
2208 int file_remove_privs(struct file *file)
2209 {
2210 return file_remove_privs_flags(file,
2211 }
2212 EXPORT_SYMBOL(file_remove_privs);
2213
2214 static int inode_needs_update_time(struct ino
2215 {
2216 int sync_it = 0;
2217 struct timespec64 now = current_time(
2218 struct timespec64 ts;
2219
2220 /* First try to exhaust all avenues t
2221 if (IS_NOCMTIME(inode))
2222 return 0;
2223
2224 ts = inode_get_mtime(inode);
2225 if (!timespec64_equal(&ts, &now))
2226 sync_it = S_MTIME;
2227
2228 ts = inode_get_ctime(inode);
2229 if (!timespec64_equal(&ts, &now))
2230 sync_it |= S_CTIME;
2231
2232 if (IS_I_VERSION(inode) && inode_iver
2233 sync_it |= S_VERSION;
2234
2235 return sync_it;
2236 }
2237
2238 static int __file_update_time(struct file *fi
2239 {
2240 int ret = 0;
2241 struct inode *inode = file_inode(file
2242
2243 /* try to update time settings */
2244 if (!mnt_get_write_access_file(file))
2245 ret = inode_update_time(inode
2246 mnt_put_write_access_file(fil
2247 }
2248
2249 return ret;
2250 }
2251
2252 /**
2253 * file_update_time - update mtime and ctime
2254 * @file: file accessed
2255 *
2256 * Update the mtime and ctime members of an i
2257 * writeback. Note that this function is mean
2258 * the file write path of filesystems, and fi
2259 * explicitly ignore updates via this functio
2260 * flag, e.g. for network filesystem where th
2261 * by the server. This can return an error fo
2262 * allocate space in order to update an inode
2263 *
2264 * Return: 0 on success, negative errno on fa
2265 */
2266 int file_update_time(struct file *file)
2267 {
2268 int ret;
2269 struct inode *inode = file_inode(file
2270
2271 ret = inode_needs_update_time(inode);
2272 if (ret <= 0)
2273 return ret;
2274
2275 return __file_update_time(file, ret);
2276 }
2277 EXPORT_SYMBOL(file_update_time);
2278
2279 /**
2280 * file_modified_flags - handle mandated vfs
2281 * @file: file that was modified
2282 * @flags: kiocb flags
2283 *
2284 * When file has been modified ensure that sp
2285 * file privileges are removed and time setti
2286 *
2287 * If IOCB_NOWAIT is set, special file privil
2288 * time settings will not be updated. It will
2289 *
2290 * Context: Caller must hold the file's inode
2291 *
2292 * Return: 0 on success, negative errno on fa
2293 */
2294 static int file_modified_flags(struct file *f
2295 {
2296 int ret;
2297 struct inode *inode = file_inode(file
2298
2299 /*
2300 * Clear the security bits if the pro
2301 * This keeps people from modifying s
2302 */
2303 ret = file_remove_privs_flags(file, f
2304 if (ret)
2305 return ret;
2306
2307 if (unlikely(file->f_mode & FMODE_NOC
2308 return 0;
2309
2310 ret = inode_needs_update_time(inode);
2311 if (ret <= 0)
2312 return ret;
2313 if (flags & IOCB_NOWAIT)
2314 return -EAGAIN;
2315
2316 return __file_update_time(file, ret);
2317 }
2318
2319 /**
2320 * file_modified - handle mandated vfs change
2321 * @file: file that was modified
2322 *
2323 * When file has been modified ensure that sp
2324 * file privileges are removed and time setti
2325 *
2326 * Context: Caller must hold the file's inode
2327 *
2328 * Return: 0 on success, negative errno on fa
2329 */
2330 int file_modified(struct file *file)
2331 {
2332 return file_modified_flags(file, 0);
2333 }
2334 EXPORT_SYMBOL(file_modified);
2335
2336 /**
2337 * kiocb_modified - handle mandated vfs chang
2338 * @iocb: iocb that was modified
2339 *
2340 * When file has been modified ensure that sp
2341 * file privileges are removed and time setti
2342 *
2343 * Context: Caller must hold the file's inode
2344 *
2345 * Return: 0 on success, negative errno on fa
2346 */
2347 int kiocb_modified(struct kiocb *iocb)
2348 {
2349 return file_modified_flags(iocb->ki_f
2350 }
2351 EXPORT_SYMBOL_GPL(kiocb_modified);
2352
2353 int inode_needs_sync(struct inode *inode)
2354 {
2355 if (IS_SYNC(inode))
2356 return 1;
2357 if (S_ISDIR(inode->i_mode) && IS_DIRS
2358 return 1;
2359 return 0;
2360 }
2361 EXPORT_SYMBOL(inode_needs_sync);
2362
2363 /*
2364 * If we try to find an inode in the inode ha
2365 * deleted, we have to wait until the filesys
2366 * deletion before reporting that it isn't fo
2367 * until the deletion _might_ have completed.
2368 * to recheck inode state.
2369 *
2370 * It doesn't matter if I_NEW is not set init
2371 * wake_up_bit(&inode->i_state, __I_NEW) afte
2372 * will DTRT.
2373 */
2374 static void __wait_on_freeing_inode(struct in
2375 {
2376 struct wait_bit_queue_entry wqe;
2377 struct wait_queue_head *wq_head;
2378
2379 /*
2380 * Handle racing against evict(), see
2381 */
2382 if (unlikely(inode_unhashed(inode)))
2383 WARN_ON(is_inode_hash_locked)
2384 spin_unlock(&inode->i_lock);
2385 return;
2386 }
2387
2388 wq_head = inode_bit_waitqueue(&wqe, i
2389 prepare_to_wait_event(wq_head, &wqe.w
2390 spin_unlock(&inode->i_lock);
2391 rcu_read_unlock();
2392 if (is_inode_hash_locked)
2393 spin_unlock(&inode_hash_lock)
2394 schedule();
2395 finish_wait(wq_head, &wqe.wq_entry);
2396 if (is_inode_hash_locked)
2397 spin_lock(&inode_hash_lock);
2398 rcu_read_lock();
2399 }
2400
2401 static __initdata unsigned long ihash_entries
2402 static int __init set_ihash_entries(char *str
2403 {
2404 if (!str)
2405 return 0;
2406 ihash_entries = simple_strtoul(str, &
2407 return 1;
2408 }
2409 __setup("ihash_entries=", set_ihash_entries);
2410
2411 /*
2412 * Initialize the waitqueues and inode hash t
2413 */
2414 void __init inode_init_early(void)
2415 {
2416 /* If hashes are distributed across N
2417 * hash allocation until vmalloc spac
2418 */
2419 if (hashdist)
2420 return;
2421
2422 inode_hashtable =
2423 alloc_large_system_hash("Inod
2424 sizeo
2425 ihash
2426 14,
2427 HASH_
2428 &i_ha
2429 &i_ha
2430 0,
2431 0);
2432 }
2433
2434 void __init inode_init(void)
2435 {
2436 /* inode slab cache */
2437 inode_cachep = kmem_cache_create("ino
2438 size
2439 0,
2440 (SLA
2441 SLAB
2442 init
2443
2444 /* Hash may have been set up in inode
2445 if (!hashdist)
2446 return;
2447
2448 inode_hashtable =
2449 alloc_large_system_hash("Inod
2450 sizeo
2451 ihash
2452 14,
2453 HASH_
2454 &i_ha
2455 &i_ha
2456 0,
2457 0);
2458 }
2459
2460 void init_special_inode(struct inode *inode,
2461 {
2462 inode->i_mode = mode;
2463 if (S_ISCHR(mode)) {
2464 inode->i_fop = &def_chr_fops;
2465 inode->i_rdev = rdev;
2466 } else if (S_ISBLK(mode)) {
2467 if (IS_ENABLED(CONFIG_BLOCK))
2468 inode->i_fop = &def_b
2469 inode->i_rdev = rdev;
2470 } else if (S_ISFIFO(mode))
2471 inode->i_fop = &pipefifo_fops
2472 else if (S_ISSOCK(mode))
2473 ; /* leave it no_open_f
2474 else
2475 printk(KERN_DEBUG "init_speci
2476 " inode %s:
2477 inode->i_in
2478 }
2479 EXPORT_SYMBOL(init_special_inode);
2480
2481 /**
2482 * inode_init_owner - Init uid,gid,mode for n
2483 * @idmap: idmap of the mount the inode was c
2484 * @inode: New inode
2485 * @dir: Directory inode
2486 * @mode: mode of the new inode
2487 *
2488 * If the inode has been created through an i
2489 * the vfsmount must be passed through @idmap
2490 * care to map the inode according to @idmap
2491 * and initializing i_uid and i_gid. On non-i
2492 * checking is to be performed on the raw ino
2493 */
2494 void inode_init_owner(struct mnt_idmap *idmap
2495 const struct inode *dir
2496 {
2497 inode_fsuid_set(inode, idmap);
2498 if (dir && dir->i_mode & S_ISGID) {
2499 inode->i_gid = dir->i_gid;
2500
2501 /* Directories are special, a
2502 if (S_ISDIR(mode))
2503 mode |= S_ISGID;
2504 } else
2505 inode_fsgid_set(inode, idmap)
2506 inode->i_mode = mode;
2507 }
2508 EXPORT_SYMBOL(inode_init_owner);
2509
2510 /**
2511 * inode_owner_or_capable - check current tas
2512 * @idmap: idmap of the mount the inode was f
2513 * @inode: inode being checked
2514 *
2515 * Return true if current either has CAP_FOWN
2516 * inode owner uid mapped, or owns the file.
2517 *
2518 * If the inode has been found through an idm
2519 * the vfsmount must be passed through @idmap
2520 * care to map the inode according to @idmap
2521 * On non-idmapped mounts or if permission ch
2522 * raw inode simply pass @nop_mnt_idmap.
2523 */
2524 bool inode_owner_or_capable(struct mnt_idmap
2525 const struct inod
2526 {
2527 vfsuid_t vfsuid;
2528 struct user_namespace *ns;
2529
2530 vfsuid = i_uid_into_vfsuid(idmap, ino
2531 if (vfsuid_eq_kuid(vfsuid, current_fs
2532 return true;
2533
2534 ns = current_user_ns();
2535 if (vfsuid_has_mapping(ns, vfsuid) &&
2536 return true;
2537 return false;
2538 }
2539 EXPORT_SYMBOL(inode_owner_or_capable);
2540
2541 /*
2542 * Direct i/o helper functions
2543 */
2544 bool inode_dio_finished(const struct inode *i
2545 {
2546 return atomic_read(&inode->i_dio_coun
2547 }
2548 EXPORT_SYMBOL(inode_dio_finished);
2549
2550 /**
2551 * inode_dio_wait - wait for outstanding DIO
2552 * @inode: inode to wait for
2553 *
2554 * Waits for all pending direct I/O requests
2555 * proceed with a truncate or equivalent oper
2556 *
2557 * Must be called under a lock that serialize
2558 * to i_dio_count, usually by inode->i_mutex.
2559 */
2560 void inode_dio_wait(struct inode *inode)
2561 {
2562 wait_var_event(&inode->i_dio_count, i
2563 }
2564 EXPORT_SYMBOL(inode_dio_wait);
2565
2566 void inode_dio_wait_interruptible(struct inod
2567 {
2568 wait_var_event_interruptible(&inode->
2569 inode_di
2570 }
2571 EXPORT_SYMBOL(inode_dio_wait_interruptible);
2572
2573 /*
2574 * inode_set_flags - atomically set some inod
2575 *
2576 * Note: the caller should be holding i_mutex
2577 * they have exclusive access to the inode st
2578 * inode is being instantiated). The reason
2579 * --- which wouldn't be necessary if all cod
2580 * i_flags actually followed this rule, is th
2581 * code path which doesn't today so we use cm
2582 * of caution.
2583 *
2584 * In the long run, i_mutex is overkill, and
2585 * at using the i_lock spinlock to protect i_
2586 * it is so documented in include/linux/fs.h
2587 * the locking convention!!
2588 */
2589 void inode_set_flags(struct inode *inode, uns
2590 unsigned int mask)
2591 {
2592 WARN_ON_ONCE(flags & ~mask);
2593 set_mask_bits(&inode->i_flags, mask,
2594 }
2595 EXPORT_SYMBOL(inode_set_flags);
2596
2597 void inode_nohighmem(struct inode *inode)
2598 {
2599 mapping_set_gfp_mask(inode->i_mapping
2600 }
2601 EXPORT_SYMBOL(inode_nohighmem);
2602
2603 /**
2604 * timestamp_truncate - Truncate timespec to
2605 * @t: Timespec
2606 * @inode: inode being updated
2607 *
2608 * Truncate a timespec to the granularity sup
2609 * containing the inode. Always rounds down.
2610 * not be 0 nor greater than a second (NSEC_P
2611 */
2612 struct timespec64 timestamp_truncate(struct t
2613 {
2614 struct super_block *sb = inode->i_sb;
2615 unsigned int gran = sb->s_time_gran;
2616
2617 t.tv_sec = clamp(t.tv_sec, sb->s_time
2618 if (unlikely(t.tv_sec == sb->s_time_m
2619 t.tv_nsec = 0;
2620
2621 /* Avoid division in the common cases
2622 if (gran == 1)
2623 ; /* nothing */
2624 else if (gran == NSEC_PER_SEC)
2625 t.tv_nsec = 0;
2626 else if (gran > 1 && gran < NSEC_PER_
2627 t.tv_nsec -= t.tv_nsec % gran
2628 else
2629 WARN(1, "invalid file time gr
2630 return t;
2631 }
2632 EXPORT_SYMBOL(timestamp_truncate);
2633
2634 /**
2635 * current_time - Return FS time
2636 * @inode: inode.
2637 *
2638 * Return the current time truncated to the t
2639 * the fs.
2640 *
2641 * Note that inode and inode->sb cannot be NU
2642 * Otherwise, the function warns and returns
2643 */
2644 struct timespec64 current_time(struct inode *
2645 {
2646 struct timespec64 now;
2647
2648 ktime_get_coarse_real_ts64(&now);
2649 return timestamp_truncate(now, inode)
2650 }
2651 EXPORT_SYMBOL(current_time);
2652
2653 /**
2654 * inode_set_ctime_current - set the ctime to
2655 * @inode: inode
2656 *
2657 * Set the inode->i_ctime to the current valu
2658 * the current value that was assigned to i_c
2659 */
2660 struct timespec64 inode_set_ctime_current(str
2661 {
2662 struct timespec64 now = current_time(
2663
2664 inode_set_ctime_to_ts(inode, now);
2665 return now;
2666 }
2667 EXPORT_SYMBOL(inode_set_ctime_current);
2668
2669 /**
2670 * in_group_or_capable - check whether caller
2671 * @idmap: idmap of the mount @inode was
2672 * @inode: inode to check
2673 * @vfsgid: the new/current vfsgid of @in
2674 *
2675 * Check wether @vfsgid is in the caller's gr
2676 * privileged with CAP_FSETID over @inode. Th
2677 * whether the setgid bit can be kept or must
2678 *
2679 * Return: true if the caller is sufficiently
2680 */
2681 bool in_group_or_capable(struct mnt_idmap *id
2682 const struct inode *
2683 {
2684 if (vfsgid_in_group_p(vfsgid))
2685 return true;
2686 if (capable_wrt_inode_uidgid(idmap, i
2687 return true;
2688 return false;
2689 }
2690 EXPORT_SYMBOL(in_group_or_capable);
2691
2692 /**
2693 * mode_strip_sgid - handle the sgid bit for
2694 * @idmap: idmap of the mount the inode was c
2695 * @dir: parent directory inode
2696 * @mode: mode of the file to be created in @
2697 *
2698 * If the @mode of the new file has both the
2699 * raised and @dir has the S_ISGID bit raised
2700 * either in the group of the parent director
2701 * in their user namespace and are privileged
2702 * In all other cases, strip the S_ISGID bit
2703 *
2704 * Return: the new mode to use for the file
2705 */
2706 umode_t mode_strip_sgid(struct mnt_idmap *idm
2707 const struct inode *d
2708 {
2709 if ((mode & (S_ISGID | S_IXGRP)) != (
2710 return mode;
2711 if (S_ISDIR(mode) || !dir || !(dir->i
2712 return mode;
2713 if (in_group_or_capable(idmap, dir, i
2714 return mode;
2715 return mode & ~S_ISGID;
2716 }
2717 EXPORT_SYMBOL(mode_strip_sgid);
2718
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