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1 | /* | |
2 | * Copyright (C) 2001 Momchil Velikov | |
3 | * Portions Copyright (C) 2001 Christoph Hellwig | |
4 | * Copyright (C) 2005 SGI, Christoph Lameter | |
5 | * Copyright (C) 2006 Nick Piggin | |
6 | * Copyright (C) 2012 Konstantin Khlebnikov | |
7 | * Copyright (C) 2016 Intel, Matthew Wilcox | |
8 | * Copyright (C) 2016 Intel, Ross Zwisler | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation; either version 2, or (at | |
13 | * your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | */ | |
24 | ||
25 | #include <linux/bitmap.h> | |
26 | #include <linux/bitops.h> | |
27 | #include <linux/cpu.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/export.h> | |
30 | #include <linux/idr.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/kmemleak.h> | |
34 | #include <linux/percpu.h> | |
35 | #include <linux/preempt.h> /* in_interrupt() */ | |
36 | #include <linux/radix-tree.h> | |
37 | #include <linux/rcupdate.h> | |
38 | #include <linux/slab.h> | |
39 | #include <linux/string.h> | |
40 | ||
41 | ||
42 | /* Number of nodes in fully populated tree of given height */ | |
43 | static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly; | |
44 | ||
45 | /* | |
46 | * Radix tree node cache. | |
47 | */ | |
48 | static struct kmem_cache *radix_tree_node_cachep; | |
49 | ||
50 | /* | |
51 | * The radix tree is variable-height, so an insert operation not only has | |
52 | * to build the branch to its corresponding item, it also has to build the | |
53 | * branch to existing items if the size has to be increased (by | |
54 | * radix_tree_extend). | |
55 | * | |
56 | * The worst case is a zero height tree with just a single item at index 0, | |
57 | * and then inserting an item at index ULONG_MAX. This requires 2 new branches | |
58 | * of RADIX_TREE_MAX_PATH size to be created, with only the root node shared. | |
59 | * Hence: | |
60 | */ | |
61 | #define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1) | |
62 | ||
63 | /* | |
64 | * The IDR does not have to be as high as the radix tree since it uses | |
65 | * signed integers, not unsigned longs. | |
66 | */ | |
67 | #define IDR_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(int) - 1) | |
68 | #define IDR_MAX_PATH (DIV_ROUND_UP(IDR_INDEX_BITS, \ | |
69 | RADIX_TREE_MAP_SHIFT)) | |
70 | #define IDR_PRELOAD_SIZE (IDR_MAX_PATH * 2 - 1) | |
71 | ||
72 | /* | |
73 | * The IDA is even shorter since it uses a bitmap at the last level. | |
74 | */ | |
75 | #define IDA_INDEX_BITS (8 * sizeof(int) - 1 - ilog2(IDA_BITMAP_BITS)) | |
76 | #define IDA_MAX_PATH (DIV_ROUND_UP(IDA_INDEX_BITS, \ | |
77 | RADIX_TREE_MAP_SHIFT)) | |
78 | #define IDA_PRELOAD_SIZE (IDA_MAX_PATH * 2 - 1) | |
79 | ||
80 | /* | |
81 | * Per-cpu pool of preloaded nodes | |
82 | */ | |
83 | struct radix_tree_preload { | |
84 | unsigned nr; | |
85 | /* nodes->parent points to next preallocated node */ | |
86 | struct radix_tree_node *nodes; | |
87 | }; | |
88 | static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; | |
89 | ||
90 | static inline struct radix_tree_node *entry_to_node(void *ptr) | |
91 | { | |
92 | return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE); | |
93 | } | |
94 | ||
95 | static inline void *node_to_entry(void *ptr) | |
96 | { | |
97 | return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE); | |
98 | } | |
99 | ||
100 | #define RADIX_TREE_RETRY node_to_entry(NULL) | |
101 | ||
102 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
103 | /* Sibling slots point directly to another slot in the same node */ | |
104 | static inline | |
105 | bool is_sibling_entry(const struct radix_tree_node *parent, void *node) | |
106 | { | |
107 | void __rcu **ptr = node; | |
108 | return (parent->slots <= ptr) && | |
109 | (ptr < parent->slots + RADIX_TREE_MAP_SIZE); | |
110 | } | |
111 | #else | |
112 | static inline | |
113 | bool is_sibling_entry(const struct radix_tree_node *parent, void *node) | |
114 | { | |
115 | return false; | |
116 | } | |
117 | #endif | |
118 | ||
119 | static inline unsigned long | |
120 | get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot) | |
121 | { | |
122 | return slot - parent->slots; | |
123 | } | |
124 | ||
125 | static unsigned int radix_tree_descend(const struct radix_tree_node *parent, | |
126 | struct radix_tree_node **nodep, unsigned long index) | |
127 | { | |
128 | unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK; | |
129 | void __rcu **entry = rcu_dereference_raw(parent->slots[offset]); | |
130 | ||
131 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
132 | if (radix_tree_is_internal_node(entry)) { | |
133 | if (is_sibling_entry(parent, entry)) { | |
134 | void __rcu **sibentry; | |
135 | sibentry = (void __rcu **) entry_to_node(entry); | |
136 | offset = get_slot_offset(parent, sibentry); | |
137 | entry = rcu_dereference_raw(*sibentry); | |
138 | } | |
139 | } | |
140 | #endif | |
141 | ||
142 | *nodep = (void *)entry; | |
143 | return offset; | |
144 | } | |
145 | ||
146 | static inline gfp_t root_gfp_mask(const struct radix_tree_root *root) | |
147 | { | |
148 | return root->gfp_mask & __GFP_BITS_MASK; | |
149 | } | |
150 | ||
151 | static inline void tag_set(struct radix_tree_node *node, unsigned int tag, | |
152 | int offset) | |
153 | { | |
154 | __set_bit(offset, node->tags[tag]); | |
155 | } | |
156 | ||
157 | static inline void tag_clear(struct radix_tree_node *node, unsigned int tag, | |
158 | int offset) | |
159 | { | |
160 | __clear_bit(offset, node->tags[tag]); | |
161 | } | |
162 | ||
163 | static inline int tag_get(const struct radix_tree_node *node, unsigned int tag, | |
164 | int offset) | |
165 | { | |
166 | return test_bit(offset, node->tags[tag]); | |
167 | } | |
168 | ||
169 | static inline void root_tag_set(struct radix_tree_root *root, unsigned tag) | |
170 | { | |
171 | root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT)); | |
172 | } | |
173 | ||
174 | static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag) | |
175 | { | |
176 | root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT)); | |
177 | } | |
178 | ||
179 | static inline void root_tag_clear_all(struct radix_tree_root *root) | |
180 | { | |
181 | root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1; | |
182 | } | |
183 | ||
184 | static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag) | |
185 | { | |
186 | return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT)); | |
187 | } | |
188 | ||
189 | static inline unsigned root_tags_get(const struct radix_tree_root *root) | |
190 | { | |
191 | return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT; | |
192 | } | |
193 | ||
194 | static inline bool is_idr(const struct radix_tree_root *root) | |
195 | { | |
196 | return !!(root->gfp_mask & ROOT_IS_IDR); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Returns 1 if any slot in the node has this tag set. | |
201 | * Otherwise returns 0. | |
202 | */ | |
203 | static inline int any_tag_set(const struct radix_tree_node *node, | |
204 | unsigned int tag) | |
205 | { | |
206 | unsigned idx; | |
207 | for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { | |
208 | if (node->tags[tag][idx]) | |
209 | return 1; | |
210 | } | |
211 | return 0; | |
212 | } | |
213 | ||
214 | static inline void all_tag_set(struct radix_tree_node *node, unsigned int tag) | |
215 | { | |
216 | bitmap_fill(node->tags[tag], RADIX_TREE_MAP_SIZE); | |
217 | } | |
218 | ||
219 | /** | |
220 | * radix_tree_find_next_bit - find the next set bit in a memory region | |
221 | * | |
222 | * @addr: The address to base the search on | |
223 | * @size: The bitmap size in bits | |
224 | * @offset: The bitnumber to start searching at | |
225 | * | |
226 | * Unrollable variant of find_next_bit() for constant size arrays. | |
227 | * Tail bits starting from size to roundup(size, BITS_PER_LONG) must be zero. | |
228 | * Returns next bit offset, or size if nothing found. | |
229 | */ | |
230 | static __always_inline unsigned long | |
231 | radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag, | |
232 | unsigned long offset) | |
233 | { | |
234 | const unsigned long *addr = node->tags[tag]; | |
235 | ||
236 | if (offset < RADIX_TREE_MAP_SIZE) { | |
237 | unsigned long tmp; | |
238 | ||
239 | addr += offset / BITS_PER_LONG; | |
240 | tmp = *addr >> (offset % BITS_PER_LONG); | |
241 | if (tmp) | |
242 | return __ffs(tmp) + offset; | |
243 | offset = (offset + BITS_PER_LONG) & ~(BITS_PER_LONG - 1); | |
244 | while (offset < RADIX_TREE_MAP_SIZE) { | |
245 | tmp = *++addr; | |
246 | if (tmp) | |
247 | return __ffs(tmp) + offset; | |
248 | offset += BITS_PER_LONG; | |
249 | } | |
250 | } | |
251 | return RADIX_TREE_MAP_SIZE; | |
252 | } | |
253 | ||
254 | static unsigned int iter_offset(const struct radix_tree_iter *iter) | |
255 | { | |
256 | return (iter->index >> iter_shift(iter)) & RADIX_TREE_MAP_MASK; | |
257 | } | |
258 | ||
259 | /* | |
260 | * The maximum index which can be stored in a radix tree | |
261 | */ | |
262 | static inline unsigned long shift_maxindex(unsigned int shift) | |
263 | { | |
264 | return (RADIX_TREE_MAP_SIZE << shift) - 1; | |
265 | } | |
266 | ||
267 | static inline unsigned long node_maxindex(const struct radix_tree_node *node) | |
268 | { | |
269 | return shift_maxindex(node->shift); | |
270 | } | |
271 | ||
272 | static unsigned long next_index(unsigned long index, | |
273 | const struct radix_tree_node *node, | |
274 | unsigned long offset) | |
275 | { | |
276 | return (index & ~node_maxindex(node)) + (offset << node->shift); | |
277 | } | |
278 | ||
279 | #ifndef __KERNEL__ | |
280 | static void dump_node(struct radix_tree_node *node, unsigned long index) | |
281 | { | |
282 | unsigned long i; | |
283 | ||
284 | pr_debug("radix node: %p offset %d indices %lu-%lu parent %p tags %lx %lx %lx shift %d count %d exceptional %d\n", | |
285 | node, node->offset, index, index | node_maxindex(node), | |
286 | node->parent, | |
287 | node->tags[0][0], node->tags[1][0], node->tags[2][0], | |
288 | node->shift, node->count, node->exceptional); | |
289 | ||
290 | for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { | |
291 | unsigned long first = index | (i << node->shift); | |
292 | unsigned long last = first | ((1UL << node->shift) - 1); | |
293 | void *entry = node->slots[i]; | |
294 | if (!entry) | |
295 | continue; | |
296 | if (entry == RADIX_TREE_RETRY) { | |
297 | pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n", | |
298 | i, first, last, node); | |
299 | } else if (!radix_tree_is_internal_node(entry)) { | |
300 | pr_debug("radix entry %p offset %ld indices %lu-%lu parent %p\n", | |
301 | entry, i, first, last, node); | |
302 | } else if (is_sibling_entry(node, entry)) { | |
303 | pr_debug("radix sblng %p offset %ld indices %lu-%lu parent %p val %p\n", | |
304 | entry, i, first, last, node, | |
305 | *(void **)entry_to_node(entry)); | |
306 | } else { | |
307 | dump_node(entry_to_node(entry), first); | |
308 | } | |
309 | } | |
310 | } | |
311 | ||
312 | /* For debug */ | |
313 | static void radix_tree_dump(struct radix_tree_root *root) | |
314 | { | |
315 | pr_debug("radix root: %p rnode %p tags %x\n", | |
316 | root, root->rnode, | |
317 | root->gfp_mask >> ROOT_TAG_SHIFT); | |
318 | if (!radix_tree_is_internal_node(root->rnode)) | |
319 | return; | |
320 | dump_node(entry_to_node(root->rnode), 0); | |
321 | } | |
322 | ||
323 | static void dump_ida_node(void *entry, unsigned long index) | |
324 | { | |
325 | unsigned long i; | |
326 | ||
327 | if (!entry) | |
328 | return; | |
329 | ||
330 | if (radix_tree_is_internal_node(entry)) { | |
331 | struct radix_tree_node *node = entry_to_node(entry); | |
332 | ||
333 | pr_debug("ida node: %p offset %d indices %lu-%lu parent %p free %lx shift %d count %d\n", | |
334 | node, node->offset, index * IDA_BITMAP_BITS, | |
335 | ((index | node_maxindex(node)) + 1) * | |
336 | IDA_BITMAP_BITS - 1, | |
337 | node->parent, node->tags[0][0], node->shift, | |
338 | node->count); | |
339 | for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) | |
340 | dump_ida_node(node->slots[i], | |
341 | index | (i << node->shift)); | |
342 | } else if (radix_tree_exceptional_entry(entry)) { | |
343 | pr_debug("ida excp: %p offset %d indices %lu-%lu data %lx\n", | |
344 | entry, (int)(index & RADIX_TREE_MAP_MASK), | |
345 | index * IDA_BITMAP_BITS, | |
346 | index * IDA_BITMAP_BITS + BITS_PER_LONG - | |
347 | RADIX_TREE_EXCEPTIONAL_SHIFT, | |
348 | (unsigned long)entry >> | |
349 | RADIX_TREE_EXCEPTIONAL_SHIFT); | |
350 | } else { | |
351 | struct ida_bitmap *bitmap = entry; | |
352 | ||
353 | pr_debug("ida btmp: %p offset %d indices %lu-%lu data", bitmap, | |
354 | (int)(index & RADIX_TREE_MAP_MASK), | |
355 | index * IDA_BITMAP_BITS, | |
356 | (index + 1) * IDA_BITMAP_BITS - 1); | |
357 | for (i = 0; i < IDA_BITMAP_LONGS; i++) | |
358 | pr_cont(" %lx", bitmap->bitmap[i]); | |
359 | pr_cont("\n"); | |
360 | } | |
361 | } | |
362 | ||
363 | static void ida_dump(struct ida *ida) | |
364 | { | |
365 | struct radix_tree_root *root = &ida->ida_rt; | |
366 | pr_debug("ida: %p node %p free %d\n", ida, root->rnode, | |
367 | root->gfp_mask >> ROOT_TAG_SHIFT); | |
368 | dump_ida_node(root->rnode, 0); | |
369 | } | |
370 | #endif | |
371 | ||
372 | /* | |
373 | * This assumes that the caller has performed appropriate preallocation, and | |
374 | * that the caller has pinned this thread of control to the current CPU. | |
375 | */ | |
376 | static struct radix_tree_node * | |
377 | radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, | |
378 | struct radix_tree_root *root, | |
379 | unsigned int shift, unsigned int offset, | |
380 | unsigned int count, unsigned int exceptional) | |
381 | { | |
382 | struct radix_tree_node *ret = NULL; | |
383 | ||
384 | /* | |
385 | * Preload code isn't irq safe and it doesn't make sense to use | |
386 | * preloading during an interrupt anyway as all the allocations have | |
387 | * to be atomic. So just do normal allocation when in interrupt. | |
388 | */ | |
389 | if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) { | |
390 | struct radix_tree_preload *rtp; | |
391 | ||
392 | /* | |
393 | * Even if the caller has preloaded, try to allocate from the | |
394 | * cache first for the new node to get accounted to the memory | |
395 | * cgroup. | |
396 | */ | |
397 | ret = kmem_cache_alloc(radix_tree_node_cachep, | |
398 | gfp_mask | __GFP_NOWARN); | |
399 | if (ret) | |
400 | goto out; | |
401 | ||
402 | /* | |
403 | * Provided the caller has preloaded here, we will always | |
404 | * succeed in getting a node here (and never reach | |
405 | * kmem_cache_alloc) | |
406 | */ | |
407 | rtp = this_cpu_ptr(&radix_tree_preloads); | |
408 | if (rtp->nr) { | |
409 | ret = rtp->nodes; | |
410 | rtp->nodes = ret->parent; | |
411 | rtp->nr--; | |
412 | } | |
413 | /* | |
414 | * Update the allocation stack trace as this is more useful | |
415 | * for debugging. | |
416 | */ | |
417 | kmemleak_update_trace(ret); | |
418 | goto out; | |
419 | } | |
420 | ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); | |
421 | out: | |
422 | BUG_ON(radix_tree_is_internal_node(ret)); | |
423 | if (ret) { | |
424 | ret->shift = shift; | |
425 | ret->offset = offset; | |
426 | ret->count = count; | |
427 | ret->exceptional = exceptional; | |
428 | ret->parent = parent; | |
429 | ret->root = root; | |
430 | } | |
431 | return ret; | |
432 | } | |
433 | ||
434 | static void radix_tree_node_rcu_free(struct rcu_head *head) | |
435 | { | |
436 | struct radix_tree_node *node = | |
437 | container_of(head, struct radix_tree_node, rcu_head); | |
438 | ||
439 | /* | |
440 | * Must only free zeroed nodes into the slab. We can be left with | |
441 | * non-NULL entries by radix_tree_free_nodes, so clear the entries | |
442 | * and tags here. | |
443 | */ | |
444 | memset(node->slots, 0, sizeof(node->slots)); | |
445 | memset(node->tags, 0, sizeof(node->tags)); | |
446 | INIT_LIST_HEAD(&node->private_list); | |
447 | ||
448 | kmem_cache_free(radix_tree_node_cachep, node); | |
449 | } | |
450 | ||
451 | static inline void | |
452 | radix_tree_node_free(struct radix_tree_node *node) | |
453 | { | |
454 | call_rcu(&node->rcu_head, radix_tree_node_rcu_free); | |
455 | } | |
456 | ||
457 | /* | |
458 | * Load up this CPU's radix_tree_node buffer with sufficient objects to | |
459 | * ensure that the addition of a single element in the tree cannot fail. On | |
460 | * success, return zero, with preemption disabled. On error, return -ENOMEM | |
461 | * with preemption not disabled. | |
462 | * | |
463 | * To make use of this facility, the radix tree must be initialised without | |
464 | * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE(). | |
465 | */ | |
466 | static __must_check int __radix_tree_preload(gfp_t gfp_mask, unsigned nr) | |
467 | { | |
468 | struct radix_tree_preload *rtp; | |
469 | struct radix_tree_node *node; | |
470 | int ret = -ENOMEM; | |
471 | ||
472 | /* | |
473 | * Nodes preloaded by one cgroup can be be used by another cgroup, so | |
474 | * they should never be accounted to any particular memory cgroup. | |
475 | */ | |
476 | gfp_mask &= ~__GFP_ACCOUNT; | |
477 | ||
478 | preempt_disable(); | |
479 | rtp = this_cpu_ptr(&radix_tree_preloads); | |
480 | while (rtp->nr < nr) { | |
481 | preempt_enable(); | |
482 | node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); | |
483 | if (node == NULL) | |
484 | goto out; | |
485 | preempt_disable(); | |
486 | rtp = this_cpu_ptr(&radix_tree_preloads); | |
487 | if (rtp->nr < nr) { | |
488 | node->parent = rtp->nodes; | |
489 | rtp->nodes = node; | |
490 | rtp->nr++; | |
491 | } else { | |
492 | kmem_cache_free(radix_tree_node_cachep, node); | |
493 | } | |
494 | } | |
495 | ret = 0; | |
496 | out: | |
497 | return ret; | |
498 | } | |
499 | ||
500 | /* | |
501 | * Load up this CPU's radix_tree_node buffer with sufficient objects to | |
502 | * ensure that the addition of a single element in the tree cannot fail. On | |
503 | * success, return zero, with preemption disabled. On error, return -ENOMEM | |
504 | * with preemption not disabled. | |
505 | * | |
506 | * To make use of this facility, the radix tree must be initialised without | |
507 | * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE(). | |
508 | */ | |
509 | int radix_tree_preload(gfp_t gfp_mask) | |
510 | { | |
511 | /* Warn on non-sensical use... */ | |
512 | WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask)); | |
513 | return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE); | |
514 | } | |
515 | EXPORT_SYMBOL(radix_tree_preload); | |
516 | ||
517 | /* | |
518 | * The same as above function, except we don't guarantee preloading happens. | |
519 | * We do it, if we decide it helps. On success, return zero with preemption | |
520 | * disabled. On error, return -ENOMEM with preemption not disabled. | |
521 | */ | |
522 | int radix_tree_maybe_preload(gfp_t gfp_mask) | |
523 | { | |
524 | if (gfpflags_allow_blocking(gfp_mask)) | |
525 | return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE); | |
526 | /* Preloading doesn't help anything with this gfp mask, skip it */ | |
527 | preempt_disable(); | |
528 | return 0; | |
529 | } | |
530 | EXPORT_SYMBOL(radix_tree_maybe_preload); | |
531 | ||
532 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
533 | /* | |
534 | * Preload with enough objects to ensure that we can split a single entry | |
535 | * of order @old_order into many entries of size @new_order | |
536 | */ | |
537 | int radix_tree_split_preload(unsigned int old_order, unsigned int new_order, | |
538 | gfp_t gfp_mask) | |
539 | { | |
540 | unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT); | |
541 | unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) - | |
542 | (new_order / RADIX_TREE_MAP_SHIFT); | |
543 | unsigned nr = 0; | |
544 | ||
545 | WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask)); | |
546 | BUG_ON(new_order >= old_order); | |
547 | ||
548 | while (layers--) | |
549 | nr = nr * RADIX_TREE_MAP_SIZE + 1; | |
550 | return __radix_tree_preload(gfp_mask, top * nr); | |
551 | } | |
552 | #endif | |
553 | ||
554 | /* | |
555 | * The same as function above, but preload number of nodes required to insert | |
556 | * (1 << order) continuous naturally-aligned elements. | |
557 | */ | |
558 | int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order) | |
559 | { | |
560 | unsigned long nr_subtrees; | |
561 | int nr_nodes, subtree_height; | |
562 | ||
563 | /* Preloading doesn't help anything with this gfp mask, skip it */ | |
564 | if (!gfpflags_allow_blocking(gfp_mask)) { | |
565 | preempt_disable(); | |
566 | return 0; | |
567 | } | |
568 | ||
569 | /* | |
570 | * Calculate number and height of fully populated subtrees it takes to | |
571 | * store (1 << order) elements. | |
572 | */ | |
573 | nr_subtrees = 1 << order; | |
574 | for (subtree_height = 0; nr_subtrees > RADIX_TREE_MAP_SIZE; | |
575 | subtree_height++) | |
576 | nr_subtrees >>= RADIX_TREE_MAP_SHIFT; | |
577 | ||
578 | /* | |
579 | * The worst case is zero height tree with a single item at index 0 and | |
580 | * then inserting items starting at ULONG_MAX - (1 << order). | |
581 | * | |
582 | * This requires RADIX_TREE_MAX_PATH nodes to build branch from root to | |
583 | * 0-index item. | |
584 | */ | |
585 | nr_nodes = RADIX_TREE_MAX_PATH; | |
586 | ||
587 | /* Plus branch to fully populated subtrees. */ | |
588 | nr_nodes += RADIX_TREE_MAX_PATH - subtree_height; | |
589 | ||
590 | /* Root node is shared. */ | |
591 | nr_nodes--; | |
592 | ||
593 | /* Plus nodes required to build subtrees. */ | |
594 | nr_nodes += nr_subtrees * height_to_maxnodes[subtree_height]; | |
595 | ||
596 | return __radix_tree_preload(gfp_mask, nr_nodes); | |
597 | } | |
598 | ||
599 | static unsigned radix_tree_load_root(const struct radix_tree_root *root, | |
600 | struct radix_tree_node **nodep, unsigned long *maxindex) | |
601 | { | |
602 | struct radix_tree_node *node = rcu_dereference_raw(root->rnode); | |
603 | ||
604 | *nodep = node; | |
605 | ||
606 | if (likely(radix_tree_is_internal_node(node))) { | |
607 | node = entry_to_node(node); | |
608 | *maxindex = node_maxindex(node); | |
609 | return node->shift + RADIX_TREE_MAP_SHIFT; | |
610 | } | |
611 | ||
612 | *maxindex = 0; | |
613 | return 0; | |
614 | } | |
615 | ||
616 | /* | |
617 | * Extend a radix tree so it can store key @index. | |
618 | */ | |
619 | static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, | |
620 | unsigned long index, unsigned int shift) | |
621 | { | |
622 | void *entry; | |
623 | unsigned int maxshift; | |
624 | int tag; | |
625 | ||
626 | /* Figure out what the shift should be. */ | |
627 | maxshift = shift; | |
628 | while (index > shift_maxindex(maxshift)) | |
629 | maxshift += RADIX_TREE_MAP_SHIFT; | |
630 | ||
631 | entry = rcu_dereference_raw(root->rnode); | |
632 | if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE))) | |
633 | goto out; | |
634 | ||
635 | do { | |
636 | struct radix_tree_node *node = radix_tree_node_alloc(gfp, NULL, | |
637 | root, shift, 0, 1, 0); | |
638 | if (!node) | |
639 | return -ENOMEM; | |
640 | ||
641 | if (is_idr(root)) { | |
642 | all_tag_set(node, IDR_FREE); | |
643 | if (!root_tag_get(root, IDR_FREE)) { | |
644 | tag_clear(node, IDR_FREE, 0); | |
645 | root_tag_set(root, IDR_FREE); | |
646 | } | |
647 | } else { | |
648 | /* Propagate the aggregated tag info to the new child */ | |
649 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { | |
650 | if (root_tag_get(root, tag)) | |
651 | tag_set(node, tag, 0); | |
652 | } | |
653 | } | |
654 | ||
655 | BUG_ON(shift > BITS_PER_LONG); | |
656 | if (radix_tree_is_internal_node(entry)) { | |
657 | entry_to_node(entry)->parent = node; | |
658 | } else if (radix_tree_exceptional_entry(entry)) { | |
659 | /* Moving an exceptional root->rnode to a node */ | |
660 | node->exceptional = 1; | |
661 | } | |
662 | /* | |
663 | * entry was already in the radix tree, so we do not need | |
664 | * rcu_assign_pointer here | |
665 | */ | |
666 | node->slots[0] = (void __rcu *)entry; | |
667 | entry = node_to_entry(node); | |
668 | rcu_assign_pointer(root->rnode, entry); | |
669 | shift += RADIX_TREE_MAP_SHIFT; | |
670 | } while (shift <= maxshift); | |
671 | out: | |
672 | return maxshift + RADIX_TREE_MAP_SHIFT; | |
673 | } | |
674 | ||
675 | /** | |
676 | * radix_tree_shrink - shrink radix tree to minimum height | |
677 | * @root radix tree root | |
678 | */ | |
679 | static inline bool radix_tree_shrink(struct radix_tree_root *root, | |
680 | radix_tree_update_node_t update_node) | |
681 | { | |
682 | bool shrunk = false; | |
683 | ||
684 | for (;;) { | |
685 | struct radix_tree_node *node = rcu_dereference_raw(root->rnode); | |
686 | struct radix_tree_node *child; | |
687 | ||
688 | if (!radix_tree_is_internal_node(node)) | |
689 | break; | |
690 | node = entry_to_node(node); | |
691 | ||
692 | /* | |
693 | * The candidate node has more than one child, or its child | |
694 | * is not at the leftmost slot, or the child is a multiorder | |
695 | * entry, we cannot shrink. | |
696 | */ | |
697 | if (node->count != 1) | |
698 | break; | |
699 | child = rcu_dereference_raw(node->slots[0]); | |
700 | if (!child) | |
701 | break; | |
702 | if (!radix_tree_is_internal_node(child) && node->shift) | |
703 | break; | |
704 | ||
705 | if (radix_tree_is_internal_node(child)) | |
706 | entry_to_node(child)->parent = NULL; | |
707 | ||
708 | /* | |
709 | * We don't need rcu_assign_pointer(), since we are simply | |
710 | * moving the node from one part of the tree to another: if it | |
711 | * was safe to dereference the old pointer to it | |
712 | * (node->slots[0]), it will be safe to dereference the new | |
713 | * one (root->rnode) as far as dependent read barriers go. | |
714 | */ | |
715 | root->rnode = (void __rcu *)child; | |
716 | if (is_idr(root) && !tag_get(node, IDR_FREE, 0)) | |
717 | root_tag_clear(root, IDR_FREE); | |
718 | ||
719 | /* | |
720 | * We have a dilemma here. The node's slot[0] must not be | |
721 | * NULLed in case there are concurrent lookups expecting to | |
722 | * find the item. However if this was a bottom-level node, | |
723 | * then it may be subject to the slot pointer being visible | |
724 | * to callers dereferencing it. If item corresponding to | |
725 | * slot[0] is subsequently deleted, these callers would expect | |
726 | * their slot to become empty sooner or later. | |
727 | * | |
728 | * For example, lockless pagecache will look up a slot, deref | |
729 | * the page pointer, and if the page has 0 refcount it means it | |
730 | * was concurrently deleted from pagecache so try the deref | |
731 | * again. Fortunately there is already a requirement for logic | |
732 | * to retry the entire slot lookup -- the indirect pointer | |
733 | * problem (replacing direct root node with an indirect pointer | |
734 | * also results in a stale slot). So tag the slot as indirect | |
735 | * to force callers to retry. | |
736 | */ | |
737 | node->count = 0; | |
738 | if (!radix_tree_is_internal_node(child)) { | |
739 | node->slots[0] = (void __rcu *)RADIX_TREE_RETRY; | |
740 | if (update_node) | |
741 | update_node(node); | |
742 | } | |
743 | ||
744 | WARN_ON_ONCE(!list_empty(&node->private_list)); | |
745 | radix_tree_node_free(node); | |
746 | shrunk = true; | |
747 | } | |
748 | ||
749 | return shrunk; | |
750 | } | |
751 | ||
752 | static bool delete_node(struct radix_tree_root *root, | |
753 | struct radix_tree_node *node, | |
754 | radix_tree_update_node_t update_node) | |
755 | { | |
756 | bool deleted = false; | |
757 | ||
758 | do { | |
759 | struct radix_tree_node *parent; | |
760 | ||
761 | if (node->count) { | |
762 | if (node_to_entry(node) == | |
763 | rcu_dereference_raw(root->rnode)) | |
764 | deleted |= radix_tree_shrink(root, | |
765 | update_node); | |
766 | return deleted; | |
767 | } | |
768 | ||
769 | parent = node->parent; | |
770 | if (parent) { | |
771 | parent->slots[node->offset] = NULL; | |
772 | parent->count--; | |
773 | } else { | |
774 | /* | |
775 | * Shouldn't the tags already have all been cleared | |
776 | * by the caller? | |
777 | */ | |
778 | if (!is_idr(root)) | |
779 | root_tag_clear_all(root); | |
780 | root->rnode = NULL; | |
781 | } | |
782 | ||
783 | WARN_ON_ONCE(!list_empty(&node->private_list)); | |
784 | radix_tree_node_free(node); | |
785 | deleted = true; | |
786 | ||
787 | node = parent; | |
788 | } while (node); | |
789 | ||
790 | return deleted; | |
791 | } | |
792 | ||
793 | /** | |
794 | * __radix_tree_create - create a slot in a radix tree | |
795 | * @root: radix tree root | |
796 | * @index: index key | |
797 | * @order: index occupies 2^order aligned slots | |
798 | * @nodep: returns node | |
799 | * @slotp: returns slot | |
800 | * | |
801 | * Create, if necessary, and return the node and slot for an item | |
802 | * at position @index in the radix tree @root. | |
803 | * | |
804 | * Until there is more than one item in the tree, no nodes are | |
805 | * allocated and @root->rnode is used as a direct slot instead of | |
806 | * pointing to a node, in which case *@nodep will be NULL. | |
807 | * | |
808 | * Returns -ENOMEM, or 0 for success. | |
809 | */ | |
810 | int __radix_tree_create(struct radix_tree_root *root, unsigned long index, | |
811 | unsigned order, struct radix_tree_node **nodep, | |
812 | void __rcu ***slotp) | |
813 | { | |
814 | struct radix_tree_node *node = NULL, *child; | |
815 | void __rcu **slot = (void __rcu **)&root->rnode; | |
816 | unsigned long maxindex; | |
817 | unsigned int shift, offset = 0; | |
818 | unsigned long max = index | ((1UL << order) - 1); | |
819 | gfp_t gfp = root_gfp_mask(root); | |
820 | ||
821 | shift = radix_tree_load_root(root, &child, &maxindex); | |
822 | ||
823 | /* Make sure the tree is high enough. */ | |
824 | if (order > 0 && max == ((1UL << order) - 1)) | |
825 | max++; | |
826 | if (max > maxindex) { | |
827 | int error = radix_tree_extend(root, gfp, max, shift); | |
828 | if (error < 0) | |
829 | return error; | |
830 | shift = error; | |
831 | child = rcu_dereference_raw(root->rnode); | |
832 | } | |
833 | ||
834 | while (shift > order) { | |
835 | shift -= RADIX_TREE_MAP_SHIFT; | |
836 | if (child == NULL) { | |
837 | /* Have to add a child node. */ | |
838 | child = radix_tree_node_alloc(gfp, node, root, shift, | |
839 | offset, 0, 0); | |
840 | if (!child) | |
841 | return -ENOMEM; | |
842 | rcu_assign_pointer(*slot, node_to_entry(child)); | |
843 | if (node) | |
844 | node->count++; | |
845 | } else if (!radix_tree_is_internal_node(child)) | |
846 | break; | |
847 | ||
848 | /* Go a level down */ | |
849 | node = entry_to_node(child); | |
850 | offset = radix_tree_descend(node, &child, index); | |
851 | slot = &node->slots[offset]; | |
852 | } | |
853 | ||
854 | if (nodep) | |
855 | *nodep = node; | |
856 | if (slotp) | |
857 | *slotp = slot; | |
858 | return 0; | |
859 | } | |
860 | ||
861 | /* | |
862 | * Free any nodes below this node. The tree is presumed to not need | |
863 | * shrinking, and any user data in the tree is presumed to not need a | |
864 | * destructor called on it. If we need to add a destructor, we can | |
865 | * add that functionality later. Note that we may not clear tags or | |
866 | * slots from the tree as an RCU walker may still have a pointer into | |
867 | * this subtree. We could replace the entries with RADIX_TREE_RETRY, | |
868 | * but we'll still have to clear those in rcu_free. | |
869 | */ | |
870 | static void radix_tree_free_nodes(struct radix_tree_node *node) | |
871 | { | |
872 | unsigned offset = 0; | |
873 | struct radix_tree_node *child = entry_to_node(node); | |
874 | ||
875 | for (;;) { | |
876 | void *entry = rcu_dereference_raw(child->slots[offset]); | |
877 | if (radix_tree_is_internal_node(entry) && | |
878 | !is_sibling_entry(child, entry)) { | |
879 | child = entry_to_node(entry); | |
880 | offset = 0; | |
881 | continue; | |
882 | } | |
883 | offset++; | |
884 | while (offset == RADIX_TREE_MAP_SIZE) { | |
885 | struct radix_tree_node *old = child; | |
886 | offset = child->offset + 1; | |
887 | child = child->parent; | |
888 | WARN_ON_ONCE(!list_empty(&old->private_list)); | |
889 | radix_tree_node_free(old); | |
890 | if (old == entry_to_node(node)) | |
891 | return; | |
892 | } | |
893 | } | |
894 | } | |
895 | ||
896 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
897 | static inline int insert_entries(struct radix_tree_node *node, | |
898 | void __rcu **slot, void *item, unsigned order, bool replace) | |
899 | { | |
900 | struct radix_tree_node *child; | |
901 | unsigned i, n, tag, offset, tags = 0; | |
902 | ||
903 | if (node) { | |
904 | if (order > node->shift) | |
905 | n = 1 << (order - node->shift); | |
906 | else | |
907 | n = 1; | |
908 | offset = get_slot_offset(node, slot); | |
909 | } else { | |
910 | n = 1; | |
911 | offset = 0; | |
912 | } | |
913 | ||
914 | if (n > 1) { | |
915 | offset = offset & ~(n - 1); | |
916 | slot = &node->slots[offset]; | |
917 | } | |
918 | child = node_to_entry(slot); | |
919 | ||
920 | for (i = 0; i < n; i++) { | |
921 | if (slot[i]) { | |
922 | if (replace) { | |
923 | node->count--; | |
924 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
925 | if (tag_get(node, tag, offset + i)) | |
926 | tags |= 1 << tag; | |
927 | } else | |
928 | return -EEXIST; | |
929 | } | |
930 | } | |
931 | ||
932 | for (i = 0; i < n; i++) { | |
933 | struct radix_tree_node *old = rcu_dereference_raw(slot[i]); | |
934 | if (i) { | |
935 | rcu_assign_pointer(slot[i], child); | |
936 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
937 | if (tags & (1 << tag)) | |
938 | tag_clear(node, tag, offset + i); | |
939 | } else { | |
940 | rcu_assign_pointer(slot[i], item); | |
941 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
942 | if (tags & (1 << tag)) | |
943 | tag_set(node, tag, offset); | |
944 | } | |
945 | if (radix_tree_is_internal_node(old) && | |
946 | !is_sibling_entry(node, old) && | |
947 | (old != RADIX_TREE_RETRY)) | |
948 | radix_tree_free_nodes(old); | |
949 | if (radix_tree_exceptional_entry(old)) | |
950 | node->exceptional--; | |
951 | } | |
952 | if (node) { | |
953 | node->count += n; | |
954 | if (radix_tree_exceptional_entry(item)) | |
955 | node->exceptional += n; | |
956 | } | |
957 | return n; | |
958 | } | |
959 | #else | |
960 | static inline int insert_entries(struct radix_tree_node *node, | |
961 | void __rcu **slot, void *item, unsigned order, bool replace) | |
962 | { | |
963 | if (*slot) | |
964 | return -EEXIST; | |
965 | rcu_assign_pointer(*slot, item); | |
966 | if (node) { | |
967 | node->count++; | |
968 | if (radix_tree_exceptional_entry(item)) | |
969 | node->exceptional++; | |
970 | } | |
971 | return 1; | |
972 | } | |
973 | #endif | |
974 | ||
975 | /** | |
976 | * __radix_tree_insert - insert into a radix tree | |
977 | * @root: radix tree root | |
978 | * @index: index key | |
979 | * @order: key covers the 2^order indices around index | |
980 | * @item: item to insert | |
981 | * | |
982 | * Insert an item into the radix tree at position @index. | |
983 | */ | |
984 | int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, | |
985 | unsigned order, void *item) | |
986 | { | |
987 | struct radix_tree_node *node; | |
988 | void __rcu **slot; | |
989 | int error; | |
990 | ||
991 | BUG_ON(radix_tree_is_internal_node(item)); | |
992 | ||
993 | error = __radix_tree_create(root, index, order, &node, &slot); | |
994 | if (error) | |
995 | return error; | |
996 | ||
997 | error = insert_entries(node, slot, item, order, false); | |
998 | if (error < 0) | |
999 | return error; | |
1000 | ||
1001 | if (node) { | |
1002 | unsigned offset = get_slot_offset(node, slot); | |
1003 | BUG_ON(tag_get(node, 0, offset)); | |
1004 | BUG_ON(tag_get(node, 1, offset)); | |
1005 | BUG_ON(tag_get(node, 2, offset)); | |
1006 | } else { | |
1007 | BUG_ON(root_tags_get(root)); | |
1008 | } | |
1009 | ||
1010 | return 0; | |
1011 | } | |
1012 | EXPORT_SYMBOL(__radix_tree_insert); | |
1013 | ||
1014 | /** | |
1015 | * __radix_tree_lookup - lookup an item in a radix tree | |
1016 | * @root: radix tree root | |
1017 | * @index: index key | |
1018 | * @nodep: returns node | |
1019 | * @slotp: returns slot | |
1020 | * | |
1021 | * Lookup and return the item at position @index in the radix | |
1022 | * tree @root. | |
1023 | * | |
1024 | * Until there is more than one item in the tree, no nodes are | |
1025 | * allocated and @root->rnode is used as a direct slot instead of | |
1026 | * pointing to a node, in which case *@nodep will be NULL. | |
1027 | */ | |
1028 | void *__radix_tree_lookup(const struct radix_tree_root *root, | |
1029 | unsigned long index, struct radix_tree_node **nodep, | |
1030 | void __rcu ***slotp) | |
1031 | { | |
1032 | struct radix_tree_node *node, *parent; | |
1033 | unsigned long maxindex; | |
1034 | void __rcu **slot; | |
1035 | ||
1036 | restart: | |
1037 | parent = NULL; | |
1038 | slot = (void __rcu **)&root->rnode; | |
1039 | radix_tree_load_root(root, &node, &maxindex); | |
1040 | if (index > maxindex) | |
1041 | return NULL; | |
1042 | ||
1043 | while (radix_tree_is_internal_node(node)) { | |
1044 | unsigned offset; | |
1045 | ||
1046 | if (node == RADIX_TREE_RETRY) | |
1047 | goto restart; | |
1048 | parent = entry_to_node(node); | |
1049 | offset = radix_tree_descend(parent, &node, index); | |
1050 | slot = parent->slots + offset; | |
1051 | } | |
1052 | ||
1053 | if (nodep) | |
1054 | *nodep = parent; | |
1055 | if (slotp) | |
1056 | *slotp = slot; | |
1057 | return node; | |
1058 | } | |
1059 | ||
1060 | /** | |
1061 | * radix_tree_lookup_slot - lookup a slot in a radix tree | |
1062 | * @root: radix tree root | |
1063 | * @index: index key | |
1064 | * | |
1065 | * Returns: the slot corresponding to the position @index in the | |
1066 | * radix tree @root. This is useful for update-if-exists operations. | |
1067 | * | |
1068 | * This function can be called under rcu_read_lock iff the slot is not | |
1069 | * modified by radix_tree_replace_slot, otherwise it must be called | |
1070 | * exclusive from other writers. Any dereference of the slot must be done | |
1071 | * using radix_tree_deref_slot. | |
1072 | */ | |
1073 | void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *root, | |
1074 | unsigned long index) | |
1075 | { | |
1076 | void __rcu **slot; | |
1077 | ||
1078 | if (!__radix_tree_lookup(root, index, NULL, &slot)) | |
1079 | return NULL; | |
1080 | return slot; | |
1081 | } | |
1082 | EXPORT_SYMBOL(radix_tree_lookup_slot); | |
1083 | ||
1084 | /** | |
1085 | * radix_tree_lookup - perform lookup operation on a radix tree | |
1086 | * @root: radix tree root | |
1087 | * @index: index key | |
1088 | * | |
1089 | * Lookup the item at the position @index in the radix tree @root. | |
1090 | * | |
1091 | * This function can be called under rcu_read_lock, however the caller | |
1092 | * must manage lifetimes of leaf nodes (eg. RCU may also be used to free | |
1093 | * them safely). No RCU barriers are required to access or modify the | |
1094 | * returned item, however. | |
1095 | */ | |
1096 | void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index) | |
1097 | { | |
1098 | return __radix_tree_lookup(root, index, NULL, NULL); | |
1099 | } | |
1100 | EXPORT_SYMBOL(radix_tree_lookup); | |
1101 | ||
1102 | static inline void replace_sibling_entries(struct radix_tree_node *node, | |
1103 | void __rcu **slot, int count, int exceptional) | |
1104 | { | |
1105 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
1106 | void *ptr = node_to_entry(slot); | |
1107 | unsigned offset = get_slot_offset(node, slot) + 1; | |
1108 | ||
1109 | while (offset < RADIX_TREE_MAP_SIZE) { | |
1110 | if (rcu_dereference_raw(node->slots[offset]) != ptr) | |
1111 | break; | |
1112 | if (count < 0) { | |
1113 | node->slots[offset] = NULL; | |
1114 | node->count--; | |
1115 | } | |
1116 | node->exceptional += exceptional; | |
1117 | offset++; | |
1118 | } | |
1119 | #endif | |
1120 | } | |
1121 | ||
1122 | static void replace_slot(void __rcu **slot, void *item, | |
1123 | struct radix_tree_node *node, int count, int exceptional) | |
1124 | { | |
1125 | if (WARN_ON_ONCE(radix_tree_is_internal_node(item))) | |
1126 | return; | |
1127 | ||
1128 | if (node && (count || exceptional)) { | |
1129 | node->count += count; | |
1130 | node->exceptional += exceptional; | |
1131 | replace_sibling_entries(node, slot, count, exceptional); | |
1132 | } | |
1133 | ||
1134 | rcu_assign_pointer(*slot, item); | |
1135 | } | |
1136 | ||
1137 | static bool node_tag_get(const struct radix_tree_root *root, | |
1138 | const struct radix_tree_node *node, | |
1139 | unsigned int tag, unsigned int offset) | |
1140 | { | |
1141 | if (node) | |
1142 | return tag_get(node, tag, offset); | |
1143 | return root_tag_get(root, tag); | |
1144 | } | |
1145 | ||
1146 | /* | |
1147 | * IDR users want to be able to store NULL in the tree, so if the slot isn't | |
1148 | * free, don't adjust the count, even if it's transitioning between NULL and | |
1149 | * non-NULL. For the IDA, we mark slots as being IDR_FREE while they still | |
1150 | * have empty bits, but it only stores NULL in slots when they're being | |
1151 | * deleted. | |
1152 | */ | |
1153 | static int calculate_count(struct radix_tree_root *root, | |
1154 | struct radix_tree_node *node, void __rcu **slot, | |
1155 | void *item, void *old) | |
1156 | { | |
1157 | if (is_idr(root)) { | |
1158 | unsigned offset = get_slot_offset(node, slot); | |
1159 | bool free = node_tag_get(root, node, IDR_FREE, offset); | |
1160 | if (!free) | |
1161 | return 0; | |
1162 | if (!old) | |
1163 | return 1; | |
1164 | } | |
1165 | return !!item - !!old; | |
1166 | } | |
1167 | ||
1168 | /** | |
1169 | * __radix_tree_replace - replace item in a slot | |
1170 | * @root: radix tree root | |
1171 | * @node: pointer to tree node | |
1172 | * @slot: pointer to slot in @node | |
1173 | * @item: new item to store in the slot. | |
1174 | * @update_node: callback for changing leaf nodes | |
1175 | * | |
1176 | * For use with __radix_tree_lookup(). Caller must hold tree write locked | |
1177 | * across slot lookup and replacement. | |
1178 | */ | |
1179 | void __radix_tree_replace(struct radix_tree_root *root, | |
1180 | struct radix_tree_node *node, | |
1181 | void __rcu **slot, void *item, | |
1182 | radix_tree_update_node_t update_node) | |
1183 | { | |
1184 | void *old = rcu_dereference_raw(*slot); | |
1185 | int exceptional = !!radix_tree_exceptional_entry(item) - | |
1186 | !!radix_tree_exceptional_entry(old); | |
1187 | int count = calculate_count(root, node, slot, item, old); | |
1188 | ||
1189 | /* | |
1190 | * This function supports replacing exceptional entries and | |
1191 | * deleting entries, but that needs accounting against the | |
1192 | * node unless the slot is root->rnode. | |
1193 | */ | |
1194 | WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) && | |
1195 | (count || exceptional)); | |
1196 | replace_slot(slot, item, node, count, exceptional); | |
1197 | ||
1198 | if (!node) | |
1199 | return; | |
1200 | ||
1201 | if (update_node) | |
1202 | update_node(node); | |
1203 | ||
1204 | delete_node(root, node, update_node); | |
1205 | } | |
1206 | ||
1207 | /** | |
1208 | * radix_tree_replace_slot - replace item in a slot | |
1209 | * @root: radix tree root | |
1210 | * @slot: pointer to slot | |
1211 | * @item: new item to store in the slot. | |
1212 | * | |
1213 | * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(), | |
1214 | * radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked | |
1215 | * across slot lookup and replacement. | |
1216 | * | |
1217 | * NOTE: This cannot be used to switch between non-entries (empty slots), | |
1218 | * regular entries, and exceptional entries, as that requires accounting | |
1219 | * inside the radix tree node. When switching from one type of entry or | |
1220 | * deleting, use __radix_tree_lookup() and __radix_tree_replace() or | |
1221 | * radix_tree_iter_replace(). | |
1222 | */ | |
1223 | void radix_tree_replace_slot(struct radix_tree_root *root, | |
1224 | void __rcu **slot, void *item) | |
1225 | { | |
1226 | __radix_tree_replace(root, NULL, slot, item, NULL); | |
1227 | } | |
1228 | EXPORT_SYMBOL(radix_tree_replace_slot); | |
1229 | ||
1230 | /** | |
1231 | * radix_tree_iter_replace - replace item in a slot | |
1232 | * @root: radix tree root | |
1233 | * @slot: pointer to slot | |
1234 | * @item: new item to store in the slot. | |
1235 | * | |
1236 | * For use with radix_tree_split() and radix_tree_for_each_slot(). | |
1237 | * Caller must hold tree write locked across split and replacement. | |
1238 | */ | |
1239 | void radix_tree_iter_replace(struct radix_tree_root *root, | |
1240 | const struct radix_tree_iter *iter, | |
1241 | void __rcu **slot, void *item) | |
1242 | { | |
1243 | __radix_tree_replace(root, iter->node, slot, item, NULL); | |
1244 | } | |
1245 | ||
1246 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
1247 | /** | |
1248 | * radix_tree_join - replace multiple entries with one multiorder entry | |
1249 | * @root: radix tree root | |
1250 | * @index: an index inside the new entry | |
1251 | * @order: order of the new entry | |
1252 | * @item: new entry | |
1253 | * | |
1254 | * Call this function to replace several entries with one larger entry. | |
1255 | * The existing entries are presumed to not need freeing as a result of | |
1256 | * this call. | |
1257 | * | |
1258 | * The replacement entry will have all the tags set on it that were set | |
1259 | * on any of the entries it is replacing. | |
1260 | */ | |
1261 | int radix_tree_join(struct radix_tree_root *root, unsigned long index, | |
1262 | unsigned order, void *item) | |
1263 | { | |
1264 | struct radix_tree_node *node; | |
1265 | void __rcu **slot; | |
1266 | int error; | |
1267 | ||
1268 | BUG_ON(radix_tree_is_internal_node(item)); | |
1269 | ||
1270 | error = __radix_tree_create(root, index, order, &node, &slot); | |
1271 | if (!error) | |
1272 | error = insert_entries(node, slot, item, order, true); | |
1273 | if (error > 0) | |
1274 | error = 0; | |
1275 | ||
1276 | return error; | |
1277 | } | |
1278 | ||
1279 | /** | |
1280 | * radix_tree_split - Split an entry into smaller entries | |
1281 | * @root: radix tree root | |
1282 | * @index: An index within the large entry | |
1283 | * @order: Order of new entries | |
1284 | * | |
1285 | * Call this function as the first step in replacing a multiorder entry | |
1286 | * with several entries of lower order. After this function returns, | |
1287 | * loop over the relevant portion of the tree using radix_tree_for_each_slot() | |
1288 | * and call radix_tree_iter_replace() to set up each new entry. | |
1289 | * | |
1290 | * The tags from this entry are replicated to all the new entries. | |
1291 | * | |
1292 | * The radix tree should be locked against modification during the entire | |
1293 | * replacement operation. Lock-free lookups will see RADIX_TREE_RETRY which | |
1294 | * should prompt RCU walkers to restart the lookup from the root. | |
1295 | */ | |
1296 | int radix_tree_split(struct radix_tree_root *root, unsigned long index, | |
1297 | unsigned order) | |
1298 | { | |
1299 | struct radix_tree_node *parent, *node, *child; | |
1300 | void __rcu **slot; | |
1301 | unsigned int offset, end; | |
1302 | unsigned n, tag, tags = 0; | |
1303 | gfp_t gfp = root_gfp_mask(root); | |
1304 | ||
1305 | if (!__radix_tree_lookup(root, index, &parent, &slot)) | |
1306 | return -ENOENT; | |
1307 | if (!parent) | |
1308 | return -ENOENT; | |
1309 | ||
1310 | offset = get_slot_offset(parent, slot); | |
1311 | ||
1312 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
1313 | if (tag_get(parent, tag, offset)) | |
1314 | tags |= 1 << tag; | |
1315 | ||
1316 | for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) { | |
1317 | if (!is_sibling_entry(parent, | |
1318 | rcu_dereference_raw(parent->slots[end]))) | |
1319 | break; | |
1320 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
1321 | if (tags & (1 << tag)) | |
1322 | tag_set(parent, tag, end); | |
1323 | /* rcu_assign_pointer ensures tags are set before RETRY */ | |
1324 | rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY); | |
1325 | } | |
1326 | rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY); | |
1327 | parent->exceptional -= (end - offset); | |
1328 | ||
1329 | if (order == parent->shift) | |
1330 | return 0; | |
1331 | if (order > parent->shift) { | |
1332 | while (offset < end) | |
1333 | offset += insert_entries(parent, &parent->slots[offset], | |
1334 | RADIX_TREE_RETRY, order, true); | |
1335 | return 0; | |
1336 | } | |
1337 | ||
1338 | node = parent; | |
1339 | ||
1340 | for (;;) { | |
1341 | if (node->shift > order) { | |
1342 | child = radix_tree_node_alloc(gfp, node, root, | |
1343 | node->shift - RADIX_TREE_MAP_SHIFT, | |
1344 | offset, 0, 0); | |
1345 | if (!child) | |
1346 | goto nomem; | |
1347 | if (node != parent) { | |
1348 | node->count++; | |
1349 | rcu_assign_pointer(node->slots[offset], | |
1350 | node_to_entry(child)); | |
1351 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
1352 | if (tags & (1 << tag)) | |
1353 | tag_set(node, tag, offset); | |
1354 | } | |
1355 | ||
1356 | node = child; | |
1357 | offset = 0; | |
1358 | continue; | |
1359 | } | |
1360 | ||
1361 | n = insert_entries(node, &node->slots[offset], | |
1362 | RADIX_TREE_RETRY, order, false); | |
1363 | BUG_ON(n > RADIX_TREE_MAP_SIZE); | |
1364 | ||
1365 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
1366 | if (tags & (1 << tag)) | |
1367 | tag_set(node, tag, offset); | |
1368 | offset += n; | |
1369 | ||
1370 | while (offset == RADIX_TREE_MAP_SIZE) { | |
1371 | if (node == parent) | |
1372 | break; | |
1373 | offset = node->offset; | |
1374 | child = node; | |
1375 | node = node->parent; | |
1376 | rcu_assign_pointer(node->slots[offset], | |
1377 | node_to_entry(child)); | |
1378 | offset++; | |
1379 | } | |
1380 | if ((node == parent) && (offset == end)) | |
1381 | return 0; | |
1382 | } | |
1383 | ||
1384 | nomem: | |
1385 | /* Shouldn't happen; did user forget to preload? */ | |
1386 | /* TODO: free all the allocated nodes */ | |
1387 | WARN_ON(1); | |
1388 | return -ENOMEM; | |
1389 | } | |
1390 | #endif | |
1391 | ||
1392 | static void node_tag_set(struct radix_tree_root *root, | |
1393 | struct radix_tree_node *node, | |
1394 | unsigned int tag, unsigned int offset) | |
1395 | { | |
1396 | while (node) { | |
1397 | if (tag_get(node, tag, offset)) | |
1398 | return; | |
1399 | tag_set(node, tag, offset); | |
1400 | offset = node->offset; | |
1401 | node = node->parent; | |
1402 | } | |
1403 | ||
1404 | if (!root_tag_get(root, tag)) | |
1405 | root_tag_set(root, tag); | |
1406 | } | |
1407 | ||
1408 | /** | |
1409 | * radix_tree_tag_set - set a tag on a radix tree node | |
1410 | * @root: radix tree root | |
1411 | * @index: index key | |
1412 | * @tag: tag index | |
1413 | * | |
1414 | * Set the search tag (which must be < RADIX_TREE_MAX_TAGS) | |
1415 | * corresponding to @index in the radix tree. From | |
1416 | * the root all the way down to the leaf node. | |
1417 | * | |
1418 | * Returns the address of the tagged item. Setting a tag on a not-present | |
1419 | * item is a bug. | |
1420 | */ | |
1421 | void *radix_tree_tag_set(struct radix_tree_root *root, | |
1422 | unsigned long index, unsigned int tag) | |
1423 | { | |
1424 | struct radix_tree_node *node, *parent; | |
1425 | unsigned long maxindex; | |
1426 | ||
1427 | radix_tree_load_root(root, &node, &maxindex); | |
1428 | BUG_ON(index > maxindex); | |
1429 | ||
1430 | while (radix_tree_is_internal_node(node)) { | |
1431 | unsigned offset; | |
1432 | ||
1433 | parent = entry_to_node(node); | |
1434 | offset = radix_tree_descend(parent, &node, index); | |
1435 | BUG_ON(!node); | |
1436 | ||
1437 | if (!tag_get(parent, tag, offset)) | |
1438 | tag_set(parent, tag, offset); | |
1439 | } | |
1440 | ||
1441 | /* set the root's tag bit */ | |
1442 | if (!root_tag_get(root, tag)) | |
1443 | root_tag_set(root, tag); | |
1444 | ||
1445 | return node; | |
1446 | } | |
1447 | EXPORT_SYMBOL(radix_tree_tag_set); | |
1448 | ||
1449 | /** | |
1450 | * radix_tree_iter_tag_set - set a tag on the current iterator entry | |
1451 | * @root: radix tree root | |
1452 | * @iter: iterator state | |
1453 | * @tag: tag to set | |
1454 | */ | |
1455 | void radix_tree_iter_tag_set(struct radix_tree_root *root, | |
1456 | const struct radix_tree_iter *iter, unsigned int tag) | |
1457 | { | |
1458 | node_tag_set(root, iter->node, tag, iter_offset(iter)); | |
1459 | } | |
1460 | ||
1461 | static void node_tag_clear(struct radix_tree_root *root, | |
1462 | struct radix_tree_node *node, | |
1463 | unsigned int tag, unsigned int offset) | |
1464 | { | |
1465 | while (node) { | |
1466 | if (!tag_get(node, tag, offset)) | |
1467 | return; | |
1468 | tag_clear(node, tag, offset); | |
1469 | if (any_tag_set(node, tag)) | |
1470 | return; | |
1471 | ||
1472 | offset = node->offset; | |
1473 | node = node->parent; | |
1474 | } | |
1475 | ||
1476 | /* clear the root's tag bit */ | |
1477 | if (root_tag_get(root, tag)) | |
1478 | root_tag_clear(root, tag); | |
1479 | } | |
1480 | ||
1481 | /** | |
1482 | * radix_tree_tag_clear - clear a tag on a radix tree node | |
1483 | * @root: radix tree root | |
1484 | * @index: index key | |
1485 | * @tag: tag index | |
1486 | * | |
1487 | * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS) | |
1488 | * corresponding to @index in the radix tree. If this causes | |
1489 | * the leaf node to have no tags set then clear the tag in the | |
1490 | * next-to-leaf node, etc. | |
1491 | * | |
1492 | * Returns the address of the tagged item on success, else NULL. ie: | |
1493 | * has the same return value and semantics as radix_tree_lookup(). | |
1494 | */ | |
1495 | void *radix_tree_tag_clear(struct radix_tree_root *root, | |
1496 | unsigned long index, unsigned int tag) | |
1497 | { | |
1498 | struct radix_tree_node *node, *parent; | |
1499 | unsigned long maxindex; | |
1500 | int uninitialized_var(offset); | |
1501 | ||
1502 | radix_tree_load_root(root, &node, &maxindex); | |
1503 | if (index > maxindex) | |
1504 | return NULL; | |
1505 | ||
1506 | parent = NULL; | |
1507 | ||
1508 | while (radix_tree_is_internal_node(node)) { | |
1509 | parent = entry_to_node(node); | |
1510 | offset = radix_tree_descend(parent, &node, index); | |
1511 | } | |
1512 | ||
1513 | if (node) | |
1514 | node_tag_clear(root, parent, tag, offset); | |
1515 | ||
1516 | return node; | |
1517 | } | |
1518 | EXPORT_SYMBOL(radix_tree_tag_clear); | |
1519 | ||
1520 | /** | |
1521 | * radix_tree_iter_tag_clear - clear a tag on the current iterator entry | |
1522 | * @root: radix tree root | |
1523 | * @iter: iterator state | |
1524 | * @tag: tag to clear | |
1525 | */ | |
1526 | void radix_tree_iter_tag_clear(struct radix_tree_root *root, | |
1527 | const struct radix_tree_iter *iter, unsigned int tag) | |
1528 | { | |
1529 | node_tag_clear(root, iter->node, tag, iter_offset(iter)); | |
1530 | } | |
1531 | ||
1532 | /** | |
1533 | * radix_tree_tag_get - get a tag on a radix tree node | |
1534 | * @root: radix tree root | |
1535 | * @index: index key | |
1536 | * @tag: tag index (< RADIX_TREE_MAX_TAGS) | |
1537 | * | |
1538 | * Return values: | |
1539 | * | |
1540 | * 0: tag not present or not set | |
1541 | * 1: tag set | |
1542 | * | |
1543 | * Note that the return value of this function may not be relied on, even if | |
1544 | * the RCU lock is held, unless tag modification and node deletion are excluded | |
1545 | * from concurrency. | |
1546 | */ | |
1547 | int radix_tree_tag_get(const struct radix_tree_root *root, | |
1548 | unsigned long index, unsigned int tag) | |
1549 | { | |
1550 | struct radix_tree_node *node, *parent; | |
1551 | unsigned long maxindex; | |
1552 | ||
1553 | if (!root_tag_get(root, tag)) | |
1554 | return 0; | |
1555 | ||
1556 | radix_tree_load_root(root, &node, &maxindex); | |
1557 | if (index > maxindex) | |
1558 | return 0; | |
1559 | ||
1560 | while (radix_tree_is_internal_node(node)) { | |
1561 | unsigned offset; | |
1562 | ||
1563 | parent = entry_to_node(node); | |
1564 | offset = radix_tree_descend(parent, &node, index); | |
1565 | ||
1566 | if (!tag_get(parent, tag, offset)) | |
1567 | return 0; | |
1568 | if (node == RADIX_TREE_RETRY) | |
1569 | break; | |
1570 | } | |
1571 | ||
1572 | return 1; | |
1573 | } | |
1574 | EXPORT_SYMBOL(radix_tree_tag_get); | |
1575 | ||
1576 | static inline void __set_iter_shift(struct radix_tree_iter *iter, | |
1577 | unsigned int shift) | |
1578 | { | |
1579 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
1580 | iter->shift = shift; | |
1581 | #endif | |
1582 | } | |
1583 | ||
1584 | /* Construct iter->tags bit-mask from node->tags[tag] array */ | |
1585 | static void set_iter_tags(struct radix_tree_iter *iter, | |
1586 | struct radix_tree_node *node, unsigned offset, | |
1587 | unsigned tag) | |
1588 | { | |
1589 | unsigned tag_long = offset / BITS_PER_LONG; | |
1590 | unsigned tag_bit = offset % BITS_PER_LONG; | |
1591 | ||
1592 | if (!node) { | |
1593 | iter->tags = 1; | |
1594 | return; | |
1595 | } | |
1596 | ||
1597 | iter->tags = node->tags[tag][tag_long] >> tag_bit; | |
1598 | ||
1599 | /* This never happens if RADIX_TREE_TAG_LONGS == 1 */ | |
1600 | if (tag_long < RADIX_TREE_TAG_LONGS - 1) { | |
1601 | /* Pick tags from next element */ | |
1602 | if (tag_bit) | |
1603 | iter->tags |= node->tags[tag][tag_long + 1] << | |
1604 | (BITS_PER_LONG - tag_bit); | |
1605 | /* Clip chunk size, here only BITS_PER_LONG tags */ | |
1606 | iter->next_index = __radix_tree_iter_add(iter, BITS_PER_LONG); | |
1607 | } | |
1608 | } | |
1609 | ||
1610 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
1611 | static void __rcu **skip_siblings(struct radix_tree_node **nodep, | |
1612 | void __rcu **slot, struct radix_tree_iter *iter) | |
1613 | { | |
1614 | while (iter->index < iter->next_index) { | |
1615 | *nodep = rcu_dereference_raw(*slot); | |
1616 | if (*nodep && !is_sibling_entry(iter->node, *nodep)) | |
1617 | return slot; | |
1618 | slot++; | |
1619 | iter->index = __radix_tree_iter_add(iter, 1); | |
1620 | iter->tags >>= 1; | |
1621 | } | |
1622 | ||
1623 | *nodep = NULL; | |
1624 | return NULL; | |
1625 | } | |
1626 | ||
1627 | void __rcu **__radix_tree_next_slot(void __rcu **slot, | |
1628 | struct radix_tree_iter *iter, unsigned flags) | |
1629 | { | |
1630 | unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; | |
1631 | struct radix_tree_node *node; | |
1632 | ||
1633 | slot = skip_siblings(&node, slot, iter); | |
1634 | ||
1635 | while (radix_tree_is_internal_node(node)) { | |
1636 | unsigned offset; | |
1637 | unsigned long next_index; | |
1638 | ||
1639 | if (node == RADIX_TREE_RETRY) | |
1640 | return slot; | |
1641 | node = entry_to_node(node); | |
1642 | iter->node = node; | |
1643 | iter->shift = node->shift; | |
1644 | ||
1645 | if (flags & RADIX_TREE_ITER_TAGGED) { | |
1646 | offset = radix_tree_find_next_bit(node, tag, 0); | |
1647 | if (offset == RADIX_TREE_MAP_SIZE) | |
1648 | return NULL; | |
1649 | slot = &node->slots[offset]; | |
1650 | iter->index = __radix_tree_iter_add(iter, offset); | |
1651 | set_iter_tags(iter, node, offset, tag); | |
1652 | node = rcu_dereference_raw(*slot); | |
1653 | } else { | |
1654 | offset = 0; | |
1655 | slot = &node->slots[0]; | |
1656 | for (;;) { | |
1657 | node = rcu_dereference_raw(*slot); | |
1658 | if (node) | |
1659 | break; | |
1660 | slot++; | |
1661 | offset++; | |
1662 | if (offset == RADIX_TREE_MAP_SIZE) | |
1663 | return NULL; | |
1664 | } | |
1665 | iter->index = __radix_tree_iter_add(iter, offset); | |
1666 | } | |
1667 | if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0)) | |
1668 | goto none; | |
1669 | next_index = (iter->index | shift_maxindex(iter->shift)) + 1; | |
1670 | if (next_index < iter->next_index) | |
1671 | iter->next_index = next_index; | |
1672 | } | |
1673 | ||
1674 | return slot; | |
1675 | none: | |
1676 | iter->next_index = 0; | |
1677 | return NULL; | |
1678 | } | |
1679 | EXPORT_SYMBOL(__radix_tree_next_slot); | |
1680 | #else | |
1681 | static void __rcu **skip_siblings(struct radix_tree_node **nodep, | |
1682 | void __rcu **slot, struct radix_tree_iter *iter) | |
1683 | { | |
1684 | return slot; | |
1685 | } | |
1686 | #endif | |
1687 | ||
1688 | void __rcu **radix_tree_iter_resume(void __rcu **slot, | |
1689 | struct radix_tree_iter *iter) | |
1690 | { | |
1691 | struct radix_tree_node *node; | |
1692 | ||
1693 | slot++; | |
1694 | iter->index = __radix_tree_iter_add(iter, 1); | |
1695 | skip_siblings(&node, slot, iter); | |
1696 | iter->next_index = iter->index; | |
1697 | iter->tags = 0; | |
1698 | return NULL; | |
1699 | } | |
1700 | EXPORT_SYMBOL(radix_tree_iter_resume); | |
1701 | ||
1702 | /** | |
1703 | * radix_tree_next_chunk - find next chunk of slots for iteration | |
1704 | * | |
1705 | * @root: radix tree root | |
1706 | * @iter: iterator state | |
1707 | * @flags: RADIX_TREE_ITER_* flags and tag index | |
1708 | * Returns: pointer to chunk first slot, or NULL if iteration is over | |
1709 | */ | |
1710 | void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root, | |
1711 | struct radix_tree_iter *iter, unsigned flags) | |
1712 | { | |
1713 | unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; | |
1714 | struct radix_tree_node *node, *child; | |
1715 | unsigned long index, offset, maxindex; | |
1716 | ||
1717 | if ((flags & RADIX_TREE_ITER_TAGGED) && !root_tag_get(root, tag)) | |
1718 | return NULL; | |
1719 | ||
1720 | /* | |
1721 | * Catch next_index overflow after ~0UL. iter->index never overflows | |
1722 | * during iterating; it can be zero only at the beginning. | |
1723 | * And we cannot overflow iter->next_index in a single step, | |
1724 | * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG. | |
1725 | * | |
1726 | * This condition also used by radix_tree_next_slot() to stop | |
1727 | * contiguous iterating, and forbid switching to the next chunk. | |
1728 | */ | |
1729 | index = iter->next_index; | |
1730 | if (!index && iter->index) | |
1731 | return NULL; | |
1732 | ||
1733 | restart: | |
1734 | radix_tree_load_root(root, &child, &maxindex); | |
1735 | if (index > maxindex) | |
1736 | return NULL; | |
1737 | if (!child) | |
1738 | return NULL; | |
1739 | ||
1740 | if (!radix_tree_is_internal_node(child)) { | |
1741 | /* Single-slot tree */ | |
1742 | iter->index = index; | |
1743 | iter->next_index = maxindex + 1; | |
1744 | iter->tags = 1; | |
1745 | iter->node = NULL; | |
1746 | __set_iter_shift(iter, 0); | |
1747 | return (void __rcu **)&root->rnode; | |
1748 | } | |
1749 | ||
1750 | do { | |
1751 | node = entry_to_node(child); | |
1752 | offset = radix_tree_descend(node, &child, index); | |
1753 | ||
1754 | if ((flags & RADIX_TREE_ITER_TAGGED) ? | |
1755 | !tag_get(node, tag, offset) : !child) { | |
1756 | /* Hole detected */ | |
1757 | if (flags & RADIX_TREE_ITER_CONTIG) | |
1758 | return NULL; | |
1759 | ||
1760 | if (flags & RADIX_TREE_ITER_TAGGED) | |
1761 | offset = radix_tree_find_next_bit(node, tag, | |
1762 | offset + 1); | |
1763 | else | |
1764 | while (++offset < RADIX_TREE_MAP_SIZE) { | |
1765 | void *slot = rcu_dereference_raw( | |
1766 | node->slots[offset]); | |
1767 | if (is_sibling_entry(node, slot)) | |
1768 | continue; | |
1769 | if (slot) | |
1770 | break; | |
1771 | } | |
1772 | index &= ~node_maxindex(node); | |
1773 | index += offset << node->shift; | |
1774 | /* Overflow after ~0UL */ | |
1775 | if (!index) | |
1776 | return NULL; | |
1777 | if (offset == RADIX_TREE_MAP_SIZE) | |
1778 | goto restart; | |
1779 | child = rcu_dereference_raw(node->slots[offset]); | |
1780 | } | |
1781 | ||
1782 | if (!child) | |
1783 | goto restart; | |
1784 | if (child == RADIX_TREE_RETRY) | |
1785 | break; | |
1786 | } while (radix_tree_is_internal_node(child)); | |
1787 | ||
1788 | /* Update the iterator state */ | |
1789 | iter->index = (index &~ node_maxindex(node)) | (offset << node->shift); | |
1790 | iter->next_index = (index | node_maxindex(node)) + 1; | |
1791 | iter->node = node; | |
1792 | __set_iter_shift(iter, node->shift); | |
1793 | ||
1794 | if (flags & RADIX_TREE_ITER_TAGGED) | |
1795 | set_iter_tags(iter, node, offset, tag); | |
1796 | ||
1797 | return node->slots + offset; | |
1798 | } | |
1799 | EXPORT_SYMBOL(radix_tree_next_chunk); | |
1800 | ||
1801 | /** | |
1802 | * radix_tree_gang_lookup - perform multiple lookup on a radix tree | |
1803 | * @root: radix tree root | |
1804 | * @results: where the results of the lookup are placed | |
1805 | * @first_index: start the lookup from this key | |
1806 | * @max_items: place up to this many items at *results | |
1807 | * | |
1808 | * Performs an index-ascending scan of the tree for present items. Places | |
1809 | * them at *@results and returns the number of items which were placed at | |
1810 | * *@results. | |
1811 | * | |
1812 | * The implementation is naive. | |
1813 | * | |
1814 | * Like radix_tree_lookup, radix_tree_gang_lookup may be called under | |
1815 | * rcu_read_lock. In this case, rather than the returned results being | |
1816 | * an atomic snapshot of the tree at a single point in time, the | |
1817 | * semantics of an RCU protected gang lookup are as though multiple | |
1818 | * radix_tree_lookups have been issued in individual locks, and results | |
1819 | * stored in 'results'. | |
1820 | */ | |
1821 | unsigned int | |
1822 | radix_tree_gang_lookup(const struct radix_tree_root *root, void **results, | |
1823 | unsigned long first_index, unsigned int max_items) | |
1824 | { | |
1825 | struct radix_tree_iter iter; | |
1826 | void __rcu **slot; | |
1827 | unsigned int ret = 0; | |
1828 | ||
1829 | if (unlikely(!max_items)) | |
1830 | return 0; | |
1831 | ||
1832 | radix_tree_for_each_slot(slot, root, &iter, first_index) { | |
1833 | results[ret] = rcu_dereference_raw(*slot); | |
1834 | if (!results[ret]) | |
1835 | continue; | |
1836 | if (radix_tree_is_internal_node(results[ret])) { | |
1837 | slot = radix_tree_iter_retry(&iter); | |
1838 | continue; | |
1839 | } | |
1840 | if (++ret == max_items) | |
1841 | break; | |
1842 | } | |
1843 | ||
1844 | return ret; | |
1845 | } | |
1846 | EXPORT_SYMBOL(radix_tree_gang_lookup); | |
1847 | ||
1848 | /** | |
1849 | * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree | |
1850 | * @root: radix tree root | |
1851 | * @results: where the results of the lookup are placed | |
1852 | * @indices: where their indices should be placed (but usually NULL) | |
1853 | * @first_index: start the lookup from this key | |
1854 | * @max_items: place up to this many items at *results | |
1855 | * | |
1856 | * Performs an index-ascending scan of the tree for present items. Places | |
1857 | * their slots at *@results and returns the number of items which were | |
1858 | * placed at *@results. | |
1859 | * | |
1860 | * The implementation is naive. | |
1861 | * | |
1862 | * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must | |
1863 | * be dereferenced with radix_tree_deref_slot, and if using only RCU | |
1864 | * protection, radix_tree_deref_slot may fail requiring a retry. | |
1865 | */ | |
1866 | unsigned int | |
1867 | radix_tree_gang_lookup_slot(const struct radix_tree_root *root, | |
1868 | void __rcu ***results, unsigned long *indices, | |
1869 | unsigned long first_index, unsigned int max_items) | |
1870 | { | |
1871 | struct radix_tree_iter iter; | |
1872 | void __rcu **slot; | |
1873 | unsigned int ret = 0; | |
1874 | ||
1875 | if (unlikely(!max_items)) | |
1876 | return 0; | |
1877 | ||
1878 | radix_tree_for_each_slot(slot, root, &iter, first_index) { | |
1879 | results[ret] = slot; | |
1880 | if (indices) | |
1881 | indices[ret] = iter.index; | |
1882 | if (++ret == max_items) | |
1883 | break; | |
1884 | } | |
1885 | ||
1886 | return ret; | |
1887 | } | |
1888 | EXPORT_SYMBOL(radix_tree_gang_lookup_slot); | |
1889 | ||
1890 | /** | |
1891 | * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree | |
1892 | * based on a tag | |
1893 | * @root: radix tree root | |
1894 | * @results: where the results of the lookup are placed | |
1895 | * @first_index: start the lookup from this key | |
1896 | * @max_items: place up to this many items at *results | |
1897 | * @tag: the tag index (< RADIX_TREE_MAX_TAGS) | |
1898 | * | |
1899 | * Performs an index-ascending scan of the tree for present items which | |
1900 | * have the tag indexed by @tag set. Places the items at *@results and | |
1901 | * returns the number of items which were placed at *@results. | |
1902 | */ | |
1903 | unsigned int | |
1904 | radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results, | |
1905 | unsigned long first_index, unsigned int max_items, | |
1906 | unsigned int tag) | |
1907 | { | |
1908 | struct radix_tree_iter iter; | |
1909 | void __rcu **slot; | |
1910 | unsigned int ret = 0; | |
1911 | ||
1912 | if (unlikely(!max_items)) | |
1913 | return 0; | |
1914 | ||
1915 | radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) { | |
1916 | results[ret] = rcu_dereference_raw(*slot); | |
1917 | if (!results[ret]) | |
1918 | continue; | |
1919 | if (radix_tree_is_internal_node(results[ret])) { | |
1920 | slot = radix_tree_iter_retry(&iter); | |
1921 | continue; | |
1922 | } | |
1923 | if (++ret == max_items) | |
1924 | break; | |
1925 | } | |
1926 | ||
1927 | return ret; | |
1928 | } | |
1929 | EXPORT_SYMBOL(radix_tree_gang_lookup_tag); | |
1930 | ||
1931 | /** | |
1932 | * radix_tree_gang_lookup_tag_slot - perform multiple slot lookup on a | |
1933 | * radix tree based on a tag | |
1934 | * @root: radix tree root | |
1935 | * @results: where the results of the lookup are placed | |
1936 | * @first_index: start the lookup from this key | |
1937 | * @max_items: place up to this many items at *results | |
1938 | * @tag: the tag index (< RADIX_TREE_MAX_TAGS) | |
1939 | * | |
1940 | * Performs an index-ascending scan of the tree for present items which | |
1941 | * have the tag indexed by @tag set. Places the slots at *@results and | |
1942 | * returns the number of slots which were placed at *@results. | |
1943 | */ | |
1944 | unsigned int | |
1945 | radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root, | |
1946 | void __rcu ***results, unsigned long first_index, | |
1947 | unsigned int max_items, unsigned int tag) | |
1948 | { | |
1949 | struct radix_tree_iter iter; | |
1950 | void __rcu **slot; | |
1951 | unsigned int ret = 0; | |
1952 | ||
1953 | if (unlikely(!max_items)) | |
1954 | return 0; | |
1955 | ||
1956 | radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) { | |
1957 | results[ret] = slot; | |
1958 | if (++ret == max_items) | |
1959 | break; | |
1960 | } | |
1961 | ||
1962 | return ret; | |
1963 | } | |
1964 | EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot); | |
1965 | ||
1966 | /** | |
1967 | * __radix_tree_delete_node - try to free node after clearing a slot | |
1968 | * @root: radix tree root | |
1969 | * @node: node containing @index | |
1970 | * @update_node: callback for changing leaf nodes | |
1971 | * | |
1972 | * After clearing the slot at @index in @node from radix tree | |
1973 | * rooted at @root, call this function to attempt freeing the | |
1974 | * node and shrinking the tree. | |
1975 | */ | |
1976 | void __radix_tree_delete_node(struct radix_tree_root *root, | |
1977 | struct radix_tree_node *node, | |
1978 | radix_tree_update_node_t update_node) | |
1979 | { | |
1980 | delete_node(root, node, update_node); | |
1981 | } | |
1982 | ||
1983 | static bool __radix_tree_delete(struct radix_tree_root *root, | |
1984 | struct radix_tree_node *node, void __rcu **slot) | |
1985 | { | |
1986 | void *old = rcu_dereference_raw(*slot); | |
1987 | int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0; | |
1988 | unsigned offset = get_slot_offset(node, slot); | |
1989 | int tag; | |
1990 | ||
1991 | if (is_idr(root)) | |
1992 | node_tag_set(root, node, IDR_FREE, offset); | |
1993 | else | |
1994 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
1995 | node_tag_clear(root, node, tag, offset); | |
1996 | ||
1997 | replace_slot(slot, NULL, node, -1, exceptional); | |
1998 | return node && delete_node(root, node, NULL); | |
1999 | } | |
2000 | ||
2001 | /** | |
2002 | * radix_tree_iter_delete - delete the entry at this iterator position | |
2003 | * @root: radix tree root | |
2004 | * @iter: iterator state | |
2005 | * @slot: pointer to slot | |
2006 | * | |
2007 | * Delete the entry at the position currently pointed to by the iterator. | |
2008 | * This may result in the current node being freed; if it is, the iterator | |
2009 | * is advanced so that it will not reference the freed memory. This | |
2010 | * function may be called without any locking if there are no other threads | |
2011 | * which can access this tree. | |
2012 | */ | |
2013 | void radix_tree_iter_delete(struct radix_tree_root *root, | |
2014 | struct radix_tree_iter *iter, void __rcu **slot) | |
2015 | { | |
2016 | if (__radix_tree_delete(root, iter->node, slot)) | |
2017 | iter->index = iter->next_index; | |
2018 | } | |
2019 | EXPORT_SYMBOL(radix_tree_iter_delete); | |
2020 | ||
2021 | /** | |
2022 | * radix_tree_delete_item - delete an item from a radix tree | |
2023 | * @root: radix tree root | |
2024 | * @index: index key | |
2025 | * @item: expected item | |
2026 | * | |
2027 | * Remove @item at @index from the radix tree rooted at @root. | |
2028 | * | |
2029 | * Return: the deleted entry, or %NULL if it was not present | |
2030 | * or the entry at the given @index was not @item. | |
2031 | */ | |
2032 | void *radix_tree_delete_item(struct radix_tree_root *root, | |
2033 | unsigned long index, void *item) | |
2034 | { | |
2035 | struct radix_tree_node *node = NULL; | |
2036 | void __rcu **slot = NULL; | |
2037 | void *entry; | |
2038 | ||
2039 | entry = __radix_tree_lookup(root, index, &node, &slot); | |
2040 | if (!slot) | |
2041 | return NULL; | |
2042 | if (!entry && (!is_idr(root) || node_tag_get(root, node, IDR_FREE, | |
2043 | get_slot_offset(node, slot)))) | |
2044 | return NULL; | |
2045 | ||
2046 | if (item && entry != item) | |
2047 | return NULL; | |
2048 | ||
2049 | __radix_tree_delete(root, node, slot); | |
2050 | ||
2051 | return entry; | |
2052 | } | |
2053 | EXPORT_SYMBOL(radix_tree_delete_item); | |
2054 | ||
2055 | /** | |
2056 | * radix_tree_delete - delete an entry from a radix tree | |
2057 | * @root: radix tree root | |
2058 | * @index: index key | |
2059 | * | |
2060 | * Remove the entry at @index from the radix tree rooted at @root. | |
2061 | * | |
2062 | * Return: The deleted entry, or %NULL if it was not present. | |
2063 | */ | |
2064 | void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) | |
2065 | { | |
2066 | return radix_tree_delete_item(root, index, NULL); | |
2067 | } | |
2068 | EXPORT_SYMBOL(radix_tree_delete); | |
2069 | ||
2070 | void radix_tree_clear_tags(struct radix_tree_root *root, | |
2071 | struct radix_tree_node *node, | |
2072 | void __rcu **slot) | |
2073 | { | |
2074 | if (node) { | |
2075 | unsigned int tag, offset = get_slot_offset(node, slot); | |
2076 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) | |
2077 | node_tag_clear(root, node, tag, offset); | |
2078 | } else { | |
2079 | root_tag_clear_all(root); | |
2080 | } | |
2081 | } | |
2082 | ||
2083 | /** | |
2084 | * radix_tree_tagged - test whether any items in the tree are tagged | |
2085 | * @root: radix tree root | |
2086 | * @tag: tag to test | |
2087 | */ | |
2088 | int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag) | |
2089 | { | |
2090 | return root_tag_get(root, tag); | |
2091 | } | |
2092 | EXPORT_SYMBOL(radix_tree_tagged); | |
2093 | ||
2094 | /** | |
2095 | * idr_preload - preload for idr_alloc() | |
2096 | * @gfp_mask: allocation mask to use for preloading | |
2097 | * | |
2098 | * Preallocate memory to use for the next call to idr_alloc(). This function | |
2099 | * returns with preemption disabled. It will be enabled by idr_preload_end(). | |
2100 | */ | |
2101 | void idr_preload(gfp_t gfp_mask) | |
2102 | { | |
2103 | if (__radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE)) | |
2104 | preempt_disable(); | |
2105 | } | |
2106 | EXPORT_SYMBOL(idr_preload); | |
2107 | ||
2108 | /** | |
2109 | * ida_pre_get - reserve resources for ida allocation | |
2110 | * @ida: ida handle | |
2111 | * @gfp: memory allocation flags | |
2112 | * | |
2113 | * This function should be called before calling ida_get_new_above(). If it | |
2114 | * is unable to allocate memory, it will return %0. On success, it returns %1. | |
2115 | */ | |
2116 | int ida_pre_get(struct ida *ida, gfp_t gfp) | |
2117 | { | |
2118 | /* | |
2119 | * The IDA API has no preload_end() equivalent. Instead, | |
2120 | * ida_get_new() can return -EAGAIN, prompting the caller | |
2121 | * to return to the ida_pre_get() step. | |
2122 | */ | |
2123 | if (!__radix_tree_preload(gfp, IDA_PRELOAD_SIZE)) | |
2124 | preempt_enable(); | |
2125 | ||
2126 | if (!this_cpu_read(ida_bitmap)) { | |
2127 | struct ida_bitmap *bitmap = kmalloc(sizeof(*bitmap), gfp); | |
2128 | if (!bitmap) | |
2129 | return 0; | |
2130 | if (this_cpu_cmpxchg(ida_bitmap, NULL, bitmap)) | |
2131 | kfree(bitmap); | |
2132 | } | |
2133 | ||
2134 | return 1; | |
2135 | } | |
2136 | EXPORT_SYMBOL(ida_pre_get); | |
2137 | ||
2138 | void __rcu **idr_get_free_cmn(struct radix_tree_root *root, | |
2139 | struct radix_tree_iter *iter, gfp_t gfp, | |
2140 | unsigned long max) | |
2141 | { | |
2142 | struct radix_tree_node *node = NULL, *child; | |
2143 | void __rcu **slot = (void __rcu **)&root->rnode; | |
2144 | unsigned long maxindex, start = iter->next_index; | |
2145 | unsigned int shift, offset = 0; | |
2146 | ||
2147 | grow: | |
2148 | shift = radix_tree_load_root(root, &child, &maxindex); | |
2149 | if (!radix_tree_tagged(root, IDR_FREE)) | |
2150 | start = max(start, maxindex + 1); | |
2151 | if (start > max) | |
2152 | return ERR_PTR(-ENOSPC); | |
2153 | ||
2154 | if (start > maxindex) { | |
2155 | int error = radix_tree_extend(root, gfp, start, shift); | |
2156 | if (error < 0) | |
2157 | return ERR_PTR(error); | |
2158 | shift = error; | |
2159 | child = rcu_dereference_raw(root->rnode); | |
2160 | } | |
2161 | ||
2162 | while (shift) { | |
2163 | shift -= RADIX_TREE_MAP_SHIFT; | |
2164 | if (child == NULL) { | |
2165 | /* Have to add a child node. */ | |
2166 | child = radix_tree_node_alloc(gfp, node, root, shift, | |
2167 | offset, 0, 0); | |
2168 | if (!child) | |
2169 | return ERR_PTR(-ENOMEM); | |
2170 | all_tag_set(child, IDR_FREE); | |
2171 | rcu_assign_pointer(*slot, node_to_entry(child)); | |
2172 | if (node) | |
2173 | node->count++; | |
2174 | } else if (!radix_tree_is_internal_node(child)) | |
2175 | break; | |
2176 | ||
2177 | node = entry_to_node(child); | |
2178 | offset = radix_tree_descend(node, &child, start); | |
2179 | if (!tag_get(node, IDR_FREE, offset)) { | |
2180 | offset = radix_tree_find_next_bit(node, IDR_FREE, | |
2181 | offset + 1); | |
2182 | start = next_index(start, node, offset); | |
2183 | if (start > max) | |
2184 | return ERR_PTR(-ENOSPC); | |
2185 | while (offset == RADIX_TREE_MAP_SIZE) { | |
2186 | offset = node->offset + 1; | |
2187 | node = node->parent; | |
2188 | if (!node) | |
2189 | goto grow; | |
2190 | shift = node->shift; | |
2191 | } | |
2192 | child = rcu_dereference_raw(node->slots[offset]); | |
2193 | } | |
2194 | slot = &node->slots[offset]; | |
2195 | } | |
2196 | ||
2197 | iter->index = start; | |
2198 | if (node) | |
2199 | iter->next_index = 1 + min(max, (start | node_maxindex(node))); | |
2200 | else | |
2201 | iter->next_index = 1; | |
2202 | iter->node = node; | |
2203 | __set_iter_shift(iter, shift); | |
2204 | set_iter_tags(iter, node, offset, IDR_FREE); | |
2205 | ||
2206 | return slot; | |
2207 | } | |
2208 | ||
2209 | /** | |
2210 | * idr_destroy - release all internal memory from an IDR | |
2211 | * @idr: idr handle | |
2212 | * | |
2213 | * After this function is called, the IDR is empty, and may be reused or | |
2214 | * the data structure containing it may be freed. | |
2215 | * | |
2216 | * A typical clean-up sequence for objects stored in an idr tree will use | |
2217 | * idr_for_each() to free all objects, if necessary, then idr_destroy() to | |
2218 | * free the memory used to keep track of those objects. | |
2219 | */ | |
2220 | void idr_destroy(struct idr *idr) | |
2221 | { | |
2222 | struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode); | |
2223 | if (radix_tree_is_internal_node(node)) | |
2224 | radix_tree_free_nodes(node); | |
2225 | idr->idr_rt.rnode = NULL; | |
2226 | root_tag_set(&idr->idr_rt, IDR_FREE); | |
2227 | } | |
2228 | EXPORT_SYMBOL(idr_destroy); | |
2229 | ||
2230 | static void | |
2231 | radix_tree_node_ctor(void *arg) | |
2232 | { | |
2233 | struct radix_tree_node *node = arg; | |
2234 | ||
2235 | memset(node, 0, sizeof(*node)); | |
2236 | INIT_LIST_HEAD(&node->private_list); | |
2237 | } | |
2238 | ||
2239 | static __init unsigned long __maxindex(unsigned int height) | |
2240 | { | |
2241 | unsigned int width = height * RADIX_TREE_MAP_SHIFT; | |
2242 | int shift = RADIX_TREE_INDEX_BITS - width; | |
2243 | ||
2244 | if (shift < 0) | |
2245 | return ~0UL; | |
2246 | if (shift >= BITS_PER_LONG) | |
2247 | return 0UL; | |
2248 | return ~0UL >> shift; | |
2249 | } | |
2250 | ||
2251 | static __init void radix_tree_init_maxnodes(void) | |
2252 | { | |
2253 | unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1]; | |
2254 | unsigned int i, j; | |
2255 | ||
2256 | for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++) | |
2257 | height_to_maxindex[i] = __maxindex(i); | |
2258 | for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) { | |
2259 | for (j = i; j > 0; j--) | |
2260 | height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1; | |
2261 | } | |
2262 | } | |
2263 | ||
2264 | static int radix_tree_cpu_dead(unsigned int cpu) | |
2265 | { | |
2266 | struct radix_tree_preload *rtp; | |
2267 | struct radix_tree_node *node; | |
2268 | ||
2269 | /* Free per-cpu pool of preloaded nodes */ | |
2270 | rtp = &per_cpu(radix_tree_preloads, cpu); | |
2271 | while (rtp->nr) { | |
2272 | node = rtp->nodes; | |
2273 | rtp->nodes = node->parent; | |
2274 | kmem_cache_free(radix_tree_node_cachep, node); | |
2275 | rtp->nr--; | |
2276 | } | |
2277 | kfree(per_cpu(ida_bitmap, cpu)); | |
2278 | per_cpu(ida_bitmap, cpu) = NULL; | |
2279 | return 0; | |
2280 | } | |
2281 | ||
2282 | void __init radix_tree_init(void) | |
2283 | { | |
2284 | int ret; | |
2285 | ||
2286 | BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32); | |
2287 | radix_tree_node_cachep = kmem_cache_create("radix_tree_node", | |
2288 | sizeof(struct radix_tree_node), 0, | |
2289 | SLAB_PANIC | SLAB_RECLAIM_ACCOUNT, | |
2290 | radix_tree_node_ctor); | |
2291 | radix_tree_init_maxnodes(); | |
2292 | ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead", | |
2293 | NULL, radix_tree_cpu_dead); | |
2294 | WARN_ON(ret < 0); | |
2295 | } |