Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2001 Momchil Velikov |
| 3 | * Portions Copyright (C) 2001 Christoph Hellwig |
Christoph Lameter | cde5353 | 2008-07-04 09:59:22 -0700 | [diff] [blame] | 4 | * Copyright (C) 2005 SGI, Christoph Lameter |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 5 | * Copyright (C) 2006 Nick Piggin |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 6 | * Copyright (C) 2012 Konstantin Khlebnikov |
Matthew Wilcox | 6b053b8 | 2016-05-20 17:02:58 -0700 | [diff] [blame] | 7 | * Copyright (C) 2016 Intel, Matthew Wilcox |
| 8 | * Copyright (C) 2016 Intel, Ross Zwisler |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 25 | #include <linux/bitmap.h> |
| 26 | #include <linux/bitops.h> |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 27 | #include <linux/cpu.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/errno.h> |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 29 | #include <linux/export.h> |
| 30 | #include <linux/idr.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/init.h> |
| 32 | #include <linux/kernel.h> |
Catalin Marinas | ce80b06 | 2014-06-06 14:38:18 -0700 | [diff] [blame] | 33 | #include <linux/kmemleak.h> |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 34 | #include <linux/percpu.h> |
Frederic Weisbecker | 92cf211 | 2015-05-12 16:41:46 +0200 | [diff] [blame] | 35 | #include <linux/preempt.h> /* in_interrupt() */ |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 36 | #include <linux/radix-tree.h> |
| 37 | #include <linux/rcupdate.h> |
| 38 | #include <linux/slab.h> |
| 39 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
| 41 | |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 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 | |
Jeff Moyer | 26fb158 | 2007-10-16 01:24:49 -0700 | [diff] [blame] | 45 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | * Radix tree node cache. |
| 47 | */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 48 | static struct kmem_cache *radix_tree_node_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | /* |
Nick Piggin | 5536805 | 2012-05-29 15:07:34 -0700 | [diff] [blame] | 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 | /* |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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 | /* |
Matthew Wilcox | 7ad3d4d | 2016-12-16 11:55:56 -0500 | [diff] [blame] | 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 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | * Per-cpu pool of preloaded nodes |
| 82 | */ |
| 83 | struct radix_tree_preload { |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 84 | unsigned nr; |
Matthew Wilcox | 1293d5c | 2017-01-16 16:41:29 -0500 | [diff] [blame] | 85 | /* nodes->parent points to next preallocated node */ |
Kirill A. Shutemov | 9d2a8da | 2015-06-25 15:02:19 -0700 | [diff] [blame] | 86 | struct radix_tree_node *nodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | }; |
Harvey Harrison | 8cef7d5 | 2009-01-06 14:40:50 -0800 | [diff] [blame] | 88 | static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 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 | |
Matthew Wilcox | a4db4dc | 2016-05-20 17:03:24 -0700 | [diff] [blame] | 95 | static inline void *node_to_entry(void *ptr) |
Nick Piggin | 27d20fd | 2010-11-11 14:05:19 -0800 | [diff] [blame] | 96 | { |
Matthew Wilcox | 30ff46cc | 2016-05-20 17:03:22 -0700 | [diff] [blame] | 97 | return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE); |
Nick Piggin | 27d20fd | 2010-11-11 14:05:19 -0800 | [diff] [blame] | 98 | } |
| 99 | |
Matthew Wilcox | a4db4dc | 2016-05-20 17:03:24 -0700 | [diff] [blame] | 100 | #define RADIX_TREE_RETRY node_to_entry(NULL) |
Matthew Wilcox | afe0e39 | 2016-05-20 17:02:17 -0700 | [diff] [blame] | 101 | |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 102 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
| 103 | /* Sibling slots point directly to another slot in the same node */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 104 | static inline |
| 105 | bool is_sibling_entry(const struct radix_tree_node *parent, void *node) |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 106 | { |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 107 | void __rcu **ptr = node; |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 108 | return (parent->slots <= ptr) && |
| 109 | (ptr < parent->slots + RADIX_TREE_MAP_SIZE); |
| 110 | } |
| 111 | #else |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 112 | static inline |
| 113 | bool is_sibling_entry(const struct radix_tree_node *parent, void *node) |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 114 | { |
| 115 | return false; |
| 116 | } |
| 117 | #endif |
| 118 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 119 | static inline unsigned long |
| 120 | get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot) |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 121 | { |
| 122 | return slot - parent->slots; |
| 123 | } |
| 124 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 125 | static unsigned int radix_tree_descend(const struct radix_tree_node *parent, |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 126 | struct radix_tree_node **nodep, unsigned long index) |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 127 | { |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 128 | unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 129 | void __rcu **entry = rcu_dereference_raw(parent->slots[offset]); |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 130 | |
| 131 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 132 | if (radix_tree_is_internal_node(entry)) { |
Linus Torvalds | 8d2c0d3 | 2016-09-25 13:32:46 -0700 | [diff] [blame] | 133 | if (is_sibling_entry(parent, entry)) { |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 134 | void __rcu **sibentry; |
| 135 | sibentry = (void __rcu **) entry_to_node(entry); |
Linus Torvalds | 8d2c0d3 | 2016-09-25 13:32:46 -0700 | [diff] [blame] | 136 | offset = get_slot_offset(parent, sibentry); |
| 137 | entry = rcu_dereference_raw(*sibentry); |
Matthew Wilcox | db050f2 | 2016-05-20 17:01:57 -0700 | [diff] [blame] | 138 | } |
| 139 | } |
| 140 | #endif |
| 141 | |
| 142 | *nodep = (void *)entry; |
| 143 | return offset; |
| 144 | } |
| 145 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 146 | static inline gfp_t root_gfp_mask(const struct radix_tree_root *root) |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 147 | { |
| 148 | return root->gfp_mask & __GFP_BITS_MASK; |
| 149 | } |
| 150 | |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 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 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 163 | static inline int tag_get(const struct radix_tree_node *node, unsigned int tag, |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 164 | int offset) |
| 165 | { |
| 166 | return test_bit(offset, node->tags[tag]); |
| 167 | } |
| 168 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 169 | static inline void root_tag_set(struct radix_tree_root *root, unsigned tag) |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 170 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 171 | root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT)); |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 172 | } |
| 173 | |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 174 | static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag) |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 175 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 176 | root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT)); |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 177 | } |
| 178 | |
| 179 | static inline void root_tag_clear_all(struct radix_tree_root *root) |
| 180 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 181 | root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1; |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 182 | } |
| 183 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 184 | static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag) |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 185 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 186 | return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT)); |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 187 | } |
| 188 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 189 | static inline unsigned root_tags_get(const struct radix_tree_root *root) |
Matthew Wilcox | 7b60e9a | 2016-05-20 17:02:23 -0700 | [diff] [blame] | 190 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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); |
Matthew Wilcox | 7b60e9a | 2016-05-20 17:02:23 -0700 | [diff] [blame] | 197 | } |
| 198 | |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 199 | /* |
| 200 | * Returns 1 if any slot in the node has this tag set. |
| 201 | * Otherwise returns 0. |
| 202 | */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 203 | static inline int any_tag_set(const struct radix_tree_node *node, |
| 204 | unsigned int tag) |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 205 | { |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 206 | unsigned idx; |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 207 | for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { |
| 208 | if (node->tags[tag][idx]) |
| 209 | return 1; |
| 210 | } |
| 211 | return 0; |
| 212 | } |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 213 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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 | |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 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 |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 231 | radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag, |
| 232 | unsigned long offset) |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 233 | { |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 234 | const unsigned long *addr = node->tags[tag]; |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 235 | |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 236 | if (offset < RADIX_TREE_MAP_SIZE) { |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 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); |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 244 | while (offset < RADIX_TREE_MAP_SIZE) { |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 245 | tmp = *++addr; |
| 246 | if (tmp) |
| 247 | return __ffs(tmp) + offset; |
| 248 | offset += BITS_PER_LONG; |
| 249 | } |
| 250 | } |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 251 | return RADIX_TREE_MAP_SIZE; |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 252 | } |
| 253 | |
Matthew Wilcox | 268f42d | 2016-12-14 15:08:55 -0800 | [diff] [blame] | 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 | |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 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 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 267 | static inline unsigned long node_maxindex(const struct radix_tree_node *node) |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 268 | { |
| 269 | return shift_maxindex(node->shift); |
| 270 | } |
| 271 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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 | |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 279 | #ifndef __KERNEL__ |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 280 | static void dump_node(struct radix_tree_node *node, unsigned long index) |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 281 | { |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 282 | unsigned long i; |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 283 | |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 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, |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 287 | node->tags[0][0], node->tags[1][0], node->tags[2][0], |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 288 | node->shift, node->count, node->exceptional); |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 289 | |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 290 | for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 291 | unsigned long first = index | (i << node->shift); |
| 292 | unsigned long last = first | ((1UL << node->shift) - 1); |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 293 | void *entry = node->slots[i]; |
| 294 | if (!entry) |
| 295 | continue; |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 296 | if (entry == RADIX_TREE_RETRY) { |
| 297 | pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n", |
| 298 | i, first, last, node); |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 299 | } else if (!radix_tree_is_internal_node(entry)) { |
Matthew Wilcox | 218ed75 | 2016-12-14 15:08:43 -0800 | [diff] [blame] | 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)); |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 306 | } else { |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 307 | dump_node(entry_to_node(entry), first); |
Ross Zwisler | 0796c58 | 2016-05-20 17:02:55 -0700 | [diff] [blame] | 308 | } |
| 309 | } |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 310 | } |
| 311 | |
| 312 | /* For debug */ |
| 313 | static void radix_tree_dump(struct radix_tree_root *root) |
| 314 | { |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 315 | pr_debug("radix root: %p rnode %p tags %x\n", |
| 316 | root, root->rnode, |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 317 | root->gfp_mask >> ROOT_TAG_SHIFT); |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 318 | if (!radix_tree_is_internal_node(root->rnode)) |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 319 | return; |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 320 | dump_node(entry_to_node(root->rnode), 0); |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 321 | } |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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)); |
Matthew Wilcox | d37cacc | 2016-12-17 08:18:17 -0500 | [diff] [blame] | 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); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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; |
Matthew Wilcox | 7ad3d4d | 2016-12-16 11:55:56 -0500 | [diff] [blame] | 366 | pr_debug("ida: %p node %p free %d\n", ida, root->rnode, |
| 367 | root->gfp_mask >> ROOT_TAG_SHIFT); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 368 | dump_ida_node(root->rnode, 0); |
| 369 | } |
Matthew Wilcox | 7cf19af | 2016-03-17 14:21:57 -0700 | [diff] [blame] | 370 | #endif |
| 371 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 * |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 377 | radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 378 | struct radix_tree_root *root, |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 379 | unsigned int shift, unsigned int offset, |
| 380 | unsigned int count, unsigned int exceptional) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | { |
Nick Piggin | e2848a0 | 2008-02-04 22:29:10 -0800 | [diff] [blame] | 382 | struct radix_tree_node *ret = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 384 | /* |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 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. |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 388 | */ |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 389 | if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | struct radix_tree_preload *rtp; |
| 391 | |
Nick Piggin | e2848a0 | 2008-02-04 22:29:10 -0800 | [diff] [blame] | 392 | /* |
Vladimir Davydov | 58e698a | 2016-03-17 14:18:36 -0700 | [diff] [blame] | 393 | * Even if the caller has preloaded, try to allocate from the |
Vladimir Davydov | 05eb6e7 | 2016-08-02 14:03:01 -0700 | [diff] [blame] | 394 | * cache first for the new node to get accounted to the memory |
| 395 | * cgroup. |
Vladimir Davydov | 58e698a | 2016-03-17 14:18:36 -0700 | [diff] [blame] | 396 | */ |
| 397 | ret = kmem_cache_alloc(radix_tree_node_cachep, |
Vladimir Davydov | 05eb6e7 | 2016-08-02 14:03:01 -0700 | [diff] [blame] | 398 | gfp_mask | __GFP_NOWARN); |
Vladimir Davydov | 58e698a | 2016-03-17 14:18:36 -0700 | [diff] [blame] | 399 | if (ret) |
| 400 | goto out; |
| 401 | |
| 402 | /* |
Nick Piggin | e2848a0 | 2008-02-04 22:29:10 -0800 | [diff] [blame] | 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 | */ |
Christoph Lameter | 7c8e018 | 2014-06-04 16:07:56 -0700 | [diff] [blame] | 407 | rtp = this_cpu_ptr(&radix_tree_preloads); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | if (rtp->nr) { |
Kirill A. Shutemov | 9d2a8da | 2015-06-25 15:02:19 -0700 | [diff] [blame] | 409 | ret = rtp->nodes; |
Matthew Wilcox | 1293d5c | 2017-01-16 16:41:29 -0500 | [diff] [blame] | 410 | rtp->nodes = ret->parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | rtp->nr--; |
| 412 | } |
Catalin Marinas | ce80b06 | 2014-06-06 14:38:18 -0700 | [diff] [blame] | 413 | /* |
| 414 | * Update the allocation stack trace as this is more useful |
| 415 | * for debugging. |
| 416 | */ |
| 417 | kmemleak_update_trace(ret); |
Vladimir Davydov | 58e698a | 2016-03-17 14:18:36 -0700 | [diff] [blame] | 418 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | } |
Vladimir Davydov | 05eb6e7 | 2016-08-02 14:03:01 -0700 | [diff] [blame] | 420 | ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); |
Vladimir Davydov | 58e698a | 2016-03-17 14:18:36 -0700 | [diff] [blame] | 421 | out: |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 422 | BUG_ON(radix_tree_is_internal_node(ret)); |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 423 | if (ret) { |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 424 | ret->shift = shift; |
| 425 | ret->offset = offset; |
| 426 | ret->count = count; |
| 427 | ret->exceptional = exceptional; |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 428 | ret->parent = parent; |
| 429 | ret->root = root; |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 430 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | return ret; |
| 432 | } |
| 433 | |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 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); |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 438 | |
| 439 | /* |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 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. |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 443 | */ |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 444 | memset(node->slots, 0, sizeof(node->slots)); |
| 445 | memset(node->tags, 0, sizeof(node->tags)); |
Matthew Wilcox | 91d9c05 | 2016-12-14 15:08:34 -0800 | [diff] [blame] | 446 | INIT_LIST_HEAD(&node->private_list); |
Nick Piggin | 643b52b | 2008-06-12 15:21:52 -0700 | [diff] [blame] | 447 | |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 448 | kmem_cache_free(radix_tree_node_cachep, node); |
| 449 | } |
| 450 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | static inline void |
| 452 | radix_tree_node_free(struct radix_tree_node *node) |
| 453 | { |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 454 | call_rcu(&node->rcu_head, radix_tree_node_rcu_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |
David Howells | b34df79 | 2009-11-19 18:11:14 +0000 | [diff] [blame] | 462 | * |
| 463 | * To make use of this facility, the radix tree must be initialised without |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 464 | * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | */ |
Matthew Wilcox | 2791653 | 2016-12-14 15:09:04 -0800 | [diff] [blame] | 466 | static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | { |
| 468 | struct radix_tree_preload *rtp; |
| 469 | struct radix_tree_node *node; |
| 470 | int ret = -ENOMEM; |
| 471 | |
Vladimir Davydov | 05eb6e7 | 2016-08-02 14:03:01 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | preempt_disable(); |
Christoph Lameter | 7c8e018 | 2014-06-04 16:07:56 -0700 | [diff] [blame] | 479 | rtp = this_cpu_ptr(&radix_tree_preloads); |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 480 | while (rtp->nr < nr) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | preempt_enable(); |
Christoph Lameter | 488514d | 2008-04-28 02:12:05 -0700 | [diff] [blame] | 482 | node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | if (node == NULL) |
| 484 | goto out; |
| 485 | preempt_disable(); |
Christoph Lameter | 7c8e018 | 2014-06-04 16:07:56 -0700 | [diff] [blame] | 486 | rtp = this_cpu_ptr(&radix_tree_preloads); |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 487 | if (rtp->nr < nr) { |
Matthew Wilcox | 1293d5c | 2017-01-16 16:41:29 -0500 | [diff] [blame] | 488 | node->parent = rtp->nodes; |
Kirill A. Shutemov | 9d2a8da | 2015-06-25 15:02:19 -0700 | [diff] [blame] | 489 | rtp->nodes = node; |
| 490 | rtp->nr++; |
| 491 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | kmem_cache_free(radix_tree_node_cachep, node); |
Kirill A. Shutemov | 9d2a8da | 2015-06-25 15:02:19 -0700 | [diff] [blame] | 493 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | } |
| 495 | ret = 0; |
| 496 | out: |
| 497 | return ret; |
| 498 | } |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 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 |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 507 | * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE(). |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 508 | */ |
| 509 | int radix_tree_preload(gfp_t gfp_mask) |
| 510 | { |
| 511 | /* Warn on non-sensical use... */ |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 512 | WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask)); |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 513 | return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE); |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 514 | } |
David Chinner | d7f0923 | 2007-07-14 16:05:04 +1000 | [diff] [blame] | 515 | EXPORT_SYMBOL(radix_tree_preload); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | |
Nick Piggin | 6e954b9 | 2006-01-08 01:01:40 -0800 | [diff] [blame] | 517 | /* |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 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 | { |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 524 | if (gfpflags_allow_blocking(gfp_mask)) |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 525 | return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE); |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 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 | |
Matthew Wilcox | 2791653 | 2016-12-14 15:09:04 -0800 | [diff] [blame] | 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 | |
Jan Kara | 5e4c0d97 | 2013-09-11 14:26:05 -0700 | [diff] [blame] | 554 | /* |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 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 | |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 599 | static unsigned radix_tree_load_root(const struct radix_tree_root *root, |
Matthew Wilcox | 1456a43 | 2016-05-20 17:02:08 -0700 | [diff] [blame] | 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 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 606 | if (likely(radix_tree_is_internal_node(node))) { |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 607 | node = entry_to_node(node); |
Matthew Wilcox | 1456a43 | 2016-05-20 17:02:08 -0700 | [diff] [blame] | 608 | *maxindex = node_maxindex(node); |
Matthew Wilcox | c12e51b | 2016-05-20 17:03:10 -0700 | [diff] [blame] | 609 | return node->shift + RADIX_TREE_MAP_SHIFT; |
Matthew Wilcox | 1456a43 | 2016-05-20 17:02:08 -0700 | [diff] [blame] | 610 | } |
| 611 | |
| 612 | *maxindex = 0; |
| 613 | return 0; |
| 614 | } |
| 615 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | /* |
| 617 | * Extend a radix tree so it can store key @index. |
| 618 | */ |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 619 | static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 620 | unsigned long index, unsigned int shift) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | { |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 622 | void *entry; |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 623 | unsigned int maxshift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | int tag; |
| 625 | |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 626 | /* Figure out what the shift should be. */ |
| 627 | maxshift = shift; |
| 628 | while (index > shift_maxindex(maxshift)) |
| 629 | maxshift += RADIX_TREE_MAP_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 631 | entry = rcu_dereference_raw(root->rnode); |
| 632 | if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | do { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 636 | struct radix_tree_node *node = radix_tree_node_alloc(gfp, NULL, |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 637 | root, shift, 0, 1, 0); |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 638 | if (!node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | return -ENOMEM; |
| 640 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 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 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | } |
| 654 | |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 655 | BUG_ON(shift > BITS_PER_LONG); |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 656 | if (radix_tree_is_internal_node(entry)) { |
| 657 | entry_to_node(entry)->parent = node; |
| 658 | } else if (radix_tree_exceptional_entry(entry)) { |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 659 | /* Moving an exceptional root->rnode to a node */ |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 660 | node->exceptional = 1; |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 661 | } |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 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); |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 669 | shift += RADIX_TREE_MAP_SHIFT; |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 670 | } while (shift <= maxshift); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | out: |
Matthew Wilcox | d089126 | 2016-05-20 17:03:19 -0700 | [diff] [blame] | 672 | return maxshift + RADIX_TREE_MAP_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | } |
| 674 | |
| 675 | /** |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 676 | * radix_tree_shrink - shrink radix tree to minimum height |
| 677 | * @root radix tree root |
| 678 | */ |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 679 | static inline bool radix_tree_shrink(struct radix_tree_root *root, |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 680 | radix_tree_update_node_t update_node, |
| 681 | void *private) |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 682 | { |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 683 | bool shrunk = false; |
| 684 | |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 685 | for (;;) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 686 | struct radix_tree_node *node = rcu_dereference_raw(root->rnode); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 687 | struct radix_tree_node *child; |
| 688 | |
| 689 | if (!radix_tree_is_internal_node(node)) |
| 690 | break; |
| 691 | node = entry_to_node(node); |
| 692 | |
| 693 | /* |
| 694 | * The candidate node has more than one child, or its child |
| 695 | * is not at the leftmost slot, or the child is a multiorder |
| 696 | * entry, we cannot shrink. |
| 697 | */ |
| 698 | if (node->count != 1) |
| 699 | break; |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 700 | child = rcu_dereference_raw(node->slots[0]); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 701 | if (!child) |
| 702 | break; |
| 703 | if (!radix_tree_is_internal_node(child) && node->shift) |
| 704 | break; |
| 705 | |
| 706 | if (radix_tree_is_internal_node(child)) |
| 707 | entry_to_node(child)->parent = NULL; |
| 708 | |
| 709 | /* |
| 710 | * We don't need rcu_assign_pointer(), since we are simply |
| 711 | * moving the node from one part of the tree to another: if it |
| 712 | * was safe to dereference the old pointer to it |
| 713 | * (node->slots[0]), it will be safe to dereference the new |
| 714 | * one (root->rnode) as far as dependent read barriers go. |
| 715 | */ |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 716 | root->rnode = (void __rcu *)child; |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 717 | if (is_idr(root) && !tag_get(node, IDR_FREE, 0)) |
| 718 | root_tag_clear(root, IDR_FREE); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 719 | |
| 720 | /* |
| 721 | * We have a dilemma here. The node's slot[0] must not be |
| 722 | * NULLed in case there are concurrent lookups expecting to |
| 723 | * find the item. However if this was a bottom-level node, |
| 724 | * then it may be subject to the slot pointer being visible |
| 725 | * to callers dereferencing it. If item corresponding to |
| 726 | * slot[0] is subsequently deleted, these callers would expect |
| 727 | * their slot to become empty sooner or later. |
| 728 | * |
| 729 | * For example, lockless pagecache will look up a slot, deref |
| 730 | * the page pointer, and if the page has 0 refcount it means it |
| 731 | * was concurrently deleted from pagecache so try the deref |
| 732 | * again. Fortunately there is already a requirement for logic |
| 733 | * to retry the entire slot lookup -- the indirect pointer |
| 734 | * problem (replacing direct root node with an indirect pointer |
| 735 | * also results in a stale slot). So tag the slot as indirect |
| 736 | * to force callers to retry. |
| 737 | */ |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 738 | node->count = 0; |
| 739 | if (!radix_tree_is_internal_node(child)) { |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 740 | node->slots[0] = (void __rcu *)RADIX_TREE_RETRY; |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 741 | if (update_node) |
| 742 | update_node(node, private); |
| 743 | } |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 744 | |
Johannes Weiner | ea07b86 | 2017-01-06 19:21:43 -0500 | [diff] [blame] | 745 | WARN_ON_ONCE(!list_empty(&node->private_list)); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 746 | radix_tree_node_free(node); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 747 | shrunk = true; |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 748 | } |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 749 | |
| 750 | return shrunk; |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 751 | } |
| 752 | |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 753 | static bool delete_node(struct radix_tree_root *root, |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 754 | struct radix_tree_node *node, |
| 755 | radix_tree_update_node_t update_node, void *private) |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 756 | { |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 757 | bool deleted = false; |
| 758 | |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 759 | do { |
| 760 | struct radix_tree_node *parent; |
| 761 | |
| 762 | if (node->count) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 763 | if (node_to_entry(node) == |
| 764 | rcu_dereference_raw(root->rnode)) |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 765 | deleted |= radix_tree_shrink(root, update_node, |
| 766 | private); |
| 767 | return deleted; |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 768 | } |
| 769 | |
| 770 | parent = node->parent; |
| 771 | if (parent) { |
| 772 | parent->slots[node->offset] = NULL; |
| 773 | parent->count--; |
| 774 | } else { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 775 | /* |
| 776 | * Shouldn't the tags already have all been cleared |
| 777 | * by the caller? |
| 778 | */ |
| 779 | if (!is_idr(root)) |
| 780 | root_tag_clear_all(root); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 781 | root->rnode = NULL; |
| 782 | } |
| 783 | |
Johannes Weiner | ea07b86 | 2017-01-06 19:21:43 -0500 | [diff] [blame] | 784 | WARN_ON_ONCE(!list_empty(&node->private_list)); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 785 | radix_tree_node_free(node); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 786 | deleted = true; |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 787 | |
| 788 | node = parent; |
| 789 | } while (node); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 790 | |
| 791 | return deleted; |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 792 | } |
| 793 | |
| 794 | /** |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 795 | * __radix_tree_create - create a slot in a radix tree |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | * @root: radix tree root |
| 797 | * @index: index key |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 798 | * @order: index occupies 2^order aligned slots |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 799 | * @nodep: returns node |
| 800 | * @slotp: returns slot |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | * |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 802 | * Create, if necessary, and return the node and slot for an item |
| 803 | * at position @index in the radix tree @root. |
| 804 | * |
| 805 | * Until there is more than one item in the tree, no nodes are |
| 806 | * allocated and @root->rnode is used as a direct slot instead of |
| 807 | * pointing to a node, in which case *@nodep will be NULL. |
| 808 | * |
| 809 | * Returns -ENOMEM, or 0 for success. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | */ |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 811 | int __radix_tree_create(struct radix_tree_root *root, unsigned long index, |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 812 | unsigned order, struct radix_tree_node **nodep, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 813 | void __rcu ***slotp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | { |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 815 | struct radix_tree_node *node = NULL, *child; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 816 | void __rcu **slot = (void __rcu **)&root->rnode; |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 817 | unsigned long maxindex; |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 818 | unsigned int shift, offset = 0; |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 819 | unsigned long max = index | ((1UL << order) - 1); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 820 | gfp_t gfp = root_gfp_mask(root); |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 821 | |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 822 | shift = radix_tree_load_root(root, &child, &maxindex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | |
| 824 | /* Make sure the tree is high enough. */ |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 825 | if (order > 0 && max == ((1UL << order) - 1)) |
| 826 | max++; |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 827 | if (max > maxindex) { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 828 | int error = radix_tree_extend(root, gfp, max, shift); |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 829 | if (error < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | return error; |
Matthew Wilcox | 49ea6eb | 2016-05-20 17:02:11 -0700 | [diff] [blame] | 831 | shift = error; |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 832 | child = rcu_dereference_raw(root->rnode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | } |
| 834 | |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 835 | while (shift > order) { |
Matthew Wilcox | c12e51b | 2016-05-20 17:03:10 -0700 | [diff] [blame] | 836 | shift -= RADIX_TREE_MAP_SHIFT; |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 837 | if (child == NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | /* Have to add a child node. */ |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 839 | child = radix_tree_node_alloc(gfp, node, root, shift, |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 840 | offset, 0, 0); |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 841 | if (!child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | return -ENOMEM; |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 843 | rcu_assign_pointer(*slot, node_to_entry(child)); |
| 844 | if (node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | node->count++; |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 846 | } else if (!radix_tree_is_internal_node(child)) |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 847 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | |
| 849 | /* Go a level down */ |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 850 | node = entry_to_node(child); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 851 | offset = radix_tree_descend(node, &child, index); |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 852 | slot = &node->slots[offset]; |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 853 | } |
| 854 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 855 | if (nodep) |
| 856 | *nodep = node; |
| 857 | if (slotp) |
Matthew Wilcox | 89148aa | 2016-05-20 17:03:42 -0700 | [diff] [blame] | 858 | *slotp = slot; |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 859 | return 0; |
| 860 | } |
| 861 | |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 862 | /* |
| 863 | * Free any nodes below this node. The tree is presumed to not need |
| 864 | * shrinking, and any user data in the tree is presumed to not need a |
| 865 | * destructor called on it. If we need to add a destructor, we can |
| 866 | * add that functionality later. Note that we may not clear tags or |
| 867 | * slots from the tree as an RCU walker may still have a pointer into |
| 868 | * this subtree. We could replace the entries with RADIX_TREE_RETRY, |
| 869 | * but we'll still have to clear those in rcu_free. |
| 870 | */ |
| 871 | static void radix_tree_free_nodes(struct radix_tree_node *node) |
| 872 | { |
| 873 | unsigned offset = 0; |
| 874 | struct radix_tree_node *child = entry_to_node(node); |
| 875 | |
| 876 | for (;;) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 877 | void *entry = rcu_dereference_raw(child->slots[offset]); |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 878 | if (radix_tree_is_internal_node(entry) && |
| 879 | !is_sibling_entry(child, entry)) { |
| 880 | child = entry_to_node(entry); |
| 881 | offset = 0; |
| 882 | continue; |
| 883 | } |
| 884 | offset++; |
| 885 | while (offset == RADIX_TREE_MAP_SIZE) { |
| 886 | struct radix_tree_node *old = child; |
| 887 | offset = child->offset + 1; |
| 888 | child = child->parent; |
Matthew Wilcox | dd040b6 | 2017-01-24 15:18:16 -0800 | [diff] [blame] | 889 | WARN_ON_ONCE(!list_empty(&old->private_list)); |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 890 | radix_tree_node_free(old); |
| 891 | if (old == entry_to_node(node)) |
| 892 | return; |
| 893 | } |
| 894 | } |
| 895 | } |
| 896 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 897 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 898 | static inline int insert_entries(struct radix_tree_node *node, |
| 899 | void __rcu **slot, void *item, unsigned order, bool replace) |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 900 | { |
| 901 | struct radix_tree_node *child; |
| 902 | unsigned i, n, tag, offset, tags = 0; |
| 903 | |
| 904 | if (node) { |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 905 | if (order > node->shift) |
| 906 | n = 1 << (order - node->shift); |
| 907 | else |
| 908 | n = 1; |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 909 | offset = get_slot_offset(node, slot); |
| 910 | } else { |
| 911 | n = 1; |
| 912 | offset = 0; |
| 913 | } |
| 914 | |
| 915 | if (n > 1) { |
| 916 | offset = offset & ~(n - 1); |
| 917 | slot = &node->slots[offset]; |
| 918 | } |
| 919 | child = node_to_entry(slot); |
| 920 | |
| 921 | for (i = 0; i < n; i++) { |
| 922 | if (slot[i]) { |
| 923 | if (replace) { |
| 924 | node->count--; |
| 925 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 926 | if (tag_get(node, tag, offset + i)) |
| 927 | tags |= 1 << tag; |
| 928 | } else |
| 929 | return -EEXIST; |
| 930 | } |
| 931 | } |
| 932 | |
| 933 | for (i = 0; i < n; i++) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 934 | struct radix_tree_node *old = rcu_dereference_raw(slot[i]); |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 935 | if (i) { |
| 936 | rcu_assign_pointer(slot[i], child); |
| 937 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 938 | if (tags & (1 << tag)) |
| 939 | tag_clear(node, tag, offset + i); |
| 940 | } else { |
| 941 | rcu_assign_pointer(slot[i], item); |
| 942 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 943 | if (tags & (1 << tag)) |
| 944 | tag_set(node, tag, offset); |
| 945 | } |
| 946 | if (radix_tree_is_internal_node(old) && |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 947 | !is_sibling_entry(node, old) && |
| 948 | (old != RADIX_TREE_RETRY)) |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 949 | radix_tree_free_nodes(old); |
| 950 | if (radix_tree_exceptional_entry(old)) |
| 951 | node->exceptional--; |
| 952 | } |
| 953 | if (node) { |
| 954 | node->count += n; |
| 955 | if (radix_tree_exceptional_entry(item)) |
| 956 | node->exceptional += n; |
| 957 | } |
| 958 | return n; |
| 959 | } |
| 960 | #else |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 961 | static inline int insert_entries(struct radix_tree_node *node, |
| 962 | void __rcu **slot, void *item, unsigned order, bool replace) |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 963 | { |
| 964 | if (*slot) |
| 965 | return -EEXIST; |
| 966 | rcu_assign_pointer(*slot, item); |
| 967 | if (node) { |
| 968 | node->count++; |
| 969 | if (radix_tree_exceptional_entry(item)) |
| 970 | node->exceptional++; |
| 971 | } |
| 972 | return 1; |
| 973 | } |
| 974 | #endif |
| 975 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 976 | /** |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 977 | * __radix_tree_insert - insert into a radix tree |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 978 | * @root: radix tree root |
| 979 | * @index: index key |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 980 | * @order: key covers the 2^order indices around index |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 981 | * @item: item to insert |
| 982 | * |
| 983 | * Insert an item into the radix tree at position @index. |
| 984 | */ |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 985 | int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, |
| 986 | unsigned order, void *item) |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 987 | { |
| 988 | struct radix_tree_node *node; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 989 | void __rcu **slot; |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 990 | int error; |
| 991 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 992 | BUG_ON(radix_tree_is_internal_node(item)); |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 993 | |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 994 | error = __radix_tree_create(root, index, order, &node, &slot); |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 995 | if (error) |
| 996 | return error; |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 997 | |
| 998 | error = insert_entries(node, slot, item, order, false); |
| 999 | if (error < 0) |
| 1000 | return error; |
Christoph Lameter | 201b626 | 2005-09-06 15:16:46 -0700 | [diff] [blame] | 1001 | |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1002 | if (node) { |
Matthew Wilcox | 7b60e9a | 2016-05-20 17:02:23 -0700 | [diff] [blame] | 1003 | unsigned offset = get_slot_offset(node, slot); |
Matthew Wilcox | 7b60e9a | 2016-05-20 17:02:23 -0700 | [diff] [blame] | 1004 | BUG_ON(tag_get(node, 0, offset)); |
| 1005 | BUG_ON(tag_get(node, 1, offset)); |
| 1006 | BUG_ON(tag_get(node, 2, offset)); |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1007 | } else { |
Matthew Wilcox | 7b60e9a | 2016-05-20 17:02:23 -0700 | [diff] [blame] | 1008 | BUG_ON(root_tags_get(root)); |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1009 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | return 0; |
| 1012 | } |
Matthew Wilcox | e614523 | 2016-03-17 14:21:54 -0700 | [diff] [blame] | 1013 | EXPORT_SYMBOL(__radix_tree_insert); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1015 | /** |
| 1016 | * __radix_tree_lookup - lookup an item in a radix tree |
| 1017 | * @root: radix tree root |
| 1018 | * @index: index key |
| 1019 | * @nodep: returns node |
| 1020 | * @slotp: returns slot |
| 1021 | * |
| 1022 | * Lookup and return the item at position @index in the radix |
| 1023 | * tree @root. |
| 1024 | * |
| 1025 | * Until there is more than one item in the tree, no nodes are |
| 1026 | * allocated and @root->rnode is used as a direct slot instead of |
| 1027 | * pointing to a node, in which case *@nodep will be NULL. |
Hans Reiser | a433136 | 2005-11-07 00:59:29 -0800 | [diff] [blame] | 1028 | */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1029 | void *__radix_tree_lookup(const struct radix_tree_root *root, |
| 1030 | unsigned long index, struct radix_tree_node **nodep, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1031 | void __rcu ***slotp) |
Hans Reiser | a433136 | 2005-11-07 00:59:29 -0800 | [diff] [blame] | 1032 | { |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1033 | struct radix_tree_node *node, *parent; |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1034 | unsigned long maxindex; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1035 | void __rcu **slot; |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1036 | |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1037 | restart: |
| 1038 | parent = NULL; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1039 | slot = (void __rcu **)&root->rnode; |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1040 | radix_tree_load_root(root, &node, &maxindex); |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1041 | if (index > maxindex) |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1042 | return NULL; |
| 1043 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1044 | while (radix_tree_is_internal_node(node)) { |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1045 | unsigned offset; |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1046 | |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1047 | if (node == RADIX_TREE_RETRY) |
| 1048 | goto restart; |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 1049 | parent = entry_to_node(node); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1050 | offset = radix_tree_descend(parent, &node, index); |
Matthew Wilcox | 8582995 | 2016-05-20 17:02:20 -0700 | [diff] [blame] | 1051 | slot = parent->slots + offset; |
| 1052 | } |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1053 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1054 | if (nodep) |
| 1055 | *nodep = parent; |
| 1056 | if (slotp) |
| 1057 | *slotp = slot; |
| 1058 | return node; |
Huang Shijie | b72b71c | 2009-06-16 15:33:42 -0700 | [diff] [blame] | 1059 | } |
| 1060 | |
| 1061 | /** |
| 1062 | * radix_tree_lookup_slot - lookup a slot in a radix tree |
| 1063 | * @root: radix tree root |
| 1064 | * @index: index key |
| 1065 | * |
| 1066 | * Returns: the slot corresponding to the position @index in the |
| 1067 | * radix tree @root. This is useful for update-if-exists operations. |
| 1068 | * |
| 1069 | * This function can be called under rcu_read_lock iff the slot is not |
| 1070 | * modified by radix_tree_replace_slot, otherwise it must be called |
| 1071 | * exclusive from other writers. Any dereference of the slot must be done |
| 1072 | * using radix_tree_deref_slot. |
| 1073 | */ |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1074 | void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *root, |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1075 | unsigned long index) |
Huang Shijie | b72b71c | 2009-06-16 15:33:42 -0700 | [diff] [blame] | 1076 | { |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1077 | void __rcu **slot; |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1078 | |
| 1079 | if (!__radix_tree_lookup(root, index, NULL, &slot)) |
| 1080 | return NULL; |
| 1081 | return slot; |
Hans Reiser | a433136 | 2005-11-07 00:59:29 -0800 | [diff] [blame] | 1082 | } |
| 1083 | EXPORT_SYMBOL(radix_tree_lookup_slot); |
| 1084 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | /** |
| 1086 | * radix_tree_lookup - perform lookup operation on a radix tree |
| 1087 | * @root: radix tree root |
| 1088 | * @index: index key |
| 1089 | * |
| 1090 | * Lookup the item at the position @index in the radix tree @root. |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1091 | * |
| 1092 | * This function can be called under rcu_read_lock, however the caller |
| 1093 | * must manage lifetimes of leaf nodes (eg. RCU may also be used to free |
| 1094 | * them safely). No RCU barriers are required to access or modify the |
| 1095 | * returned item, however. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1096 | */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1097 | void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1098 | { |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1099 | return __radix_tree_lookup(root, index, NULL, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | } |
| 1101 | EXPORT_SYMBOL(radix_tree_lookup); |
| 1102 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1103 | static inline void replace_sibling_entries(struct radix_tree_node *node, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1104 | void __rcu **slot, int count, int exceptional) |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1105 | { |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1106 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
| 1107 | void *ptr = node_to_entry(slot); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1108 | unsigned offset = get_slot_offset(node, slot) + 1; |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1109 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1110 | while (offset < RADIX_TREE_MAP_SIZE) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 1111 | if (rcu_dereference_raw(node->slots[offset]) != ptr) |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1112 | break; |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1113 | if (count < 0) { |
| 1114 | node->slots[offset] = NULL; |
| 1115 | node->count--; |
| 1116 | } |
| 1117 | node->exceptional += exceptional; |
| 1118 | offset++; |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1119 | } |
| 1120 | #endif |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1121 | } |
| 1122 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1123 | static void replace_slot(void __rcu **slot, void *item, |
| 1124 | struct radix_tree_node *node, int count, int exceptional) |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1125 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1126 | if (WARN_ON_ONCE(radix_tree_is_internal_node(item))) |
| 1127 | return; |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1128 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1129 | if (node && (count || exceptional)) { |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 1130 | node->count += count; |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1131 | node->exceptional += exceptional; |
| 1132 | replace_sibling_entries(node, slot, count, exceptional); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 1133 | } |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1134 | |
| 1135 | rcu_assign_pointer(*slot, item); |
| 1136 | } |
| 1137 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1138 | static bool node_tag_get(const struct radix_tree_root *root, |
| 1139 | const struct radix_tree_node *node, |
| 1140 | unsigned int tag, unsigned int offset) |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1141 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1142 | if (node) |
| 1143 | return tag_get(node, tag, offset); |
| 1144 | return root_tag_get(root, tag); |
| 1145 | } |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1146 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1147 | /* |
| 1148 | * IDR users want to be able to store NULL in the tree, so if the slot isn't |
| 1149 | * free, don't adjust the count, even if it's transitioning between NULL and |
| 1150 | * non-NULL. For the IDA, we mark slots as being IDR_FREE while they still |
| 1151 | * have empty bits, but it only stores NULL in slots when they're being |
| 1152 | * deleted. |
| 1153 | */ |
| 1154 | static int calculate_count(struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1155 | struct radix_tree_node *node, void __rcu **slot, |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1156 | void *item, void *old) |
| 1157 | { |
| 1158 | if (is_idr(root)) { |
| 1159 | unsigned offset = get_slot_offset(node, slot); |
| 1160 | bool free = node_tag_get(root, node, IDR_FREE, offset); |
| 1161 | if (!free) |
| 1162 | return 0; |
| 1163 | if (!old) |
| 1164 | return 1; |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1165 | } |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1166 | return !!item - !!old; |
Matthew Wilcox | a90eb3a | 2016-12-14 15:09:07 -0800 | [diff] [blame] | 1167 | } |
| 1168 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | /** |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1170 | * __radix_tree_replace - replace item in a slot |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 1171 | * @root: radix tree root |
| 1172 | * @node: pointer to tree node |
| 1173 | * @slot: pointer to slot in @node |
| 1174 | * @item: new item to store in the slot. |
| 1175 | * @update_node: callback for changing leaf nodes |
| 1176 | * @private: private data to pass to @update_node |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1177 | * |
| 1178 | * For use with __radix_tree_lookup(). Caller must hold tree write locked |
| 1179 | * across slot lookup and replacement. |
| 1180 | */ |
| 1181 | void __radix_tree_replace(struct radix_tree_root *root, |
| 1182 | struct radix_tree_node *node, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1183 | void __rcu **slot, void *item, |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 1184 | radix_tree_update_node_t update_node, void *private) |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1185 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1186 | void *old = rcu_dereference_raw(*slot); |
| 1187 | int exceptional = !!radix_tree_exceptional_entry(item) - |
| 1188 | !!radix_tree_exceptional_entry(old); |
| 1189 | int count = calculate_count(root, node, slot, item, old); |
| 1190 | |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1191 | /* |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 1192 | * This function supports replacing exceptional entries and |
| 1193 | * deleting entries, but that needs accounting against the |
| 1194 | * node unless the slot is root->rnode. |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1195 | */ |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1196 | WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) && |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1197 | (count || exceptional)); |
| 1198 | replace_slot(slot, item, node, count, exceptional); |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 1199 | |
Johannes Weiner | 4d693d0 | 2016-12-12 16:43:49 -0800 | [diff] [blame] | 1200 | if (!node) |
| 1201 | return; |
| 1202 | |
| 1203 | if (update_node) |
| 1204 | update_node(node, private); |
| 1205 | |
| 1206 | delete_node(root, node, update_node, private); |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1207 | } |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1208 | |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1209 | /** |
| 1210 | * radix_tree_replace_slot - replace item in a slot |
| 1211 | * @root: radix tree root |
| 1212 | * @slot: pointer to slot |
| 1213 | * @item: new item to store in the slot. |
| 1214 | * |
| 1215 | * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(), |
| 1216 | * radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked |
| 1217 | * across slot lookup and replacement. |
| 1218 | * |
| 1219 | * NOTE: This cannot be used to switch between non-entries (empty slots), |
| 1220 | * regular entries, and exceptional entries, as that requires accounting |
Johannes Weiner | f4b109c | 2016-12-12 16:43:46 -0800 | [diff] [blame] | 1221 | * inside the radix tree node. When switching from one type of entry or |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1222 | * deleting, use __radix_tree_lookup() and __radix_tree_replace() or |
| 1223 | * radix_tree_iter_replace(). |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1224 | */ |
| 1225 | void radix_tree_replace_slot(struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1226 | void __rcu **slot, void *item) |
Johannes Weiner | 6d75f36 | 2016-12-12 16:43:43 -0800 | [diff] [blame] | 1227 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1228 | __radix_tree_replace(root, NULL, slot, item, NULL, NULL); |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1229 | } |
Song Liu | 10257d7 | 2017-01-11 10:00:51 -0800 | [diff] [blame] | 1230 | EXPORT_SYMBOL(radix_tree_replace_slot); |
Johannes Weiner | f794243 | 2016-12-12 16:43:41 -0800 | [diff] [blame] | 1231 | |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1232 | /** |
| 1233 | * radix_tree_iter_replace - replace item in a slot |
| 1234 | * @root: radix tree root |
| 1235 | * @slot: pointer to slot |
| 1236 | * @item: new item to store in the slot. |
| 1237 | * |
| 1238 | * For use with radix_tree_split() and radix_tree_for_each_slot(). |
| 1239 | * Caller must hold tree write locked across split and replacement. |
| 1240 | */ |
| 1241 | void radix_tree_iter_replace(struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1242 | const struct radix_tree_iter *iter, |
| 1243 | void __rcu **slot, void *item) |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1244 | { |
| 1245 | __radix_tree_replace(root, iter->node, slot, item, NULL, NULL); |
| 1246 | } |
| 1247 | |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 1248 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
| 1249 | /** |
| 1250 | * radix_tree_join - replace multiple entries with one multiorder entry |
| 1251 | * @root: radix tree root |
| 1252 | * @index: an index inside the new entry |
| 1253 | * @order: order of the new entry |
| 1254 | * @item: new entry |
| 1255 | * |
| 1256 | * Call this function to replace several entries with one larger entry. |
| 1257 | * The existing entries are presumed to not need freeing as a result of |
| 1258 | * this call. |
| 1259 | * |
| 1260 | * The replacement entry will have all the tags set on it that were set |
| 1261 | * on any of the entries it is replacing. |
| 1262 | */ |
| 1263 | int radix_tree_join(struct radix_tree_root *root, unsigned long index, |
| 1264 | unsigned order, void *item) |
| 1265 | { |
| 1266 | struct radix_tree_node *node; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1267 | void __rcu **slot; |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 1268 | int error; |
| 1269 | |
| 1270 | BUG_ON(radix_tree_is_internal_node(item)); |
| 1271 | |
| 1272 | error = __radix_tree_create(root, index, order, &node, &slot); |
| 1273 | if (!error) |
| 1274 | error = insert_entries(node, slot, item, order, true); |
| 1275 | if (error > 0) |
| 1276 | error = 0; |
| 1277 | |
| 1278 | return error; |
| 1279 | } |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1280 | |
| 1281 | /** |
| 1282 | * radix_tree_split - Split an entry into smaller entries |
| 1283 | * @root: radix tree root |
| 1284 | * @index: An index within the large entry |
| 1285 | * @order: Order of new entries |
| 1286 | * |
| 1287 | * Call this function as the first step in replacing a multiorder entry |
| 1288 | * with several entries of lower order. After this function returns, |
| 1289 | * loop over the relevant portion of the tree using radix_tree_for_each_slot() |
| 1290 | * and call radix_tree_iter_replace() to set up each new entry. |
| 1291 | * |
| 1292 | * The tags from this entry are replicated to all the new entries. |
| 1293 | * |
| 1294 | * The radix tree should be locked against modification during the entire |
| 1295 | * replacement operation. Lock-free lookups will see RADIX_TREE_RETRY which |
| 1296 | * should prompt RCU walkers to restart the lookup from the root. |
| 1297 | */ |
| 1298 | int radix_tree_split(struct radix_tree_root *root, unsigned long index, |
| 1299 | unsigned order) |
| 1300 | { |
| 1301 | struct radix_tree_node *parent, *node, *child; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1302 | void __rcu **slot; |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1303 | unsigned int offset, end; |
| 1304 | unsigned n, tag, tags = 0; |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1305 | gfp_t gfp = root_gfp_mask(root); |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1306 | |
| 1307 | if (!__radix_tree_lookup(root, index, &parent, &slot)) |
| 1308 | return -ENOENT; |
| 1309 | if (!parent) |
| 1310 | return -ENOENT; |
| 1311 | |
| 1312 | offset = get_slot_offset(parent, slot); |
| 1313 | |
| 1314 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 1315 | if (tag_get(parent, tag, offset)) |
| 1316 | tags |= 1 << tag; |
| 1317 | |
| 1318 | for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 1319 | if (!is_sibling_entry(parent, |
| 1320 | rcu_dereference_raw(parent->slots[end]))) |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1321 | break; |
| 1322 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 1323 | if (tags & (1 << tag)) |
| 1324 | tag_set(parent, tag, end); |
| 1325 | /* rcu_assign_pointer ensures tags are set before RETRY */ |
| 1326 | rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY); |
| 1327 | } |
| 1328 | rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY); |
| 1329 | parent->exceptional -= (end - offset); |
| 1330 | |
| 1331 | if (order == parent->shift) |
| 1332 | return 0; |
| 1333 | if (order > parent->shift) { |
| 1334 | while (offset < end) |
| 1335 | offset += insert_entries(parent, &parent->slots[offset], |
| 1336 | RADIX_TREE_RETRY, order, true); |
| 1337 | return 0; |
| 1338 | } |
| 1339 | |
| 1340 | node = parent; |
| 1341 | |
| 1342 | for (;;) { |
| 1343 | if (node->shift > order) { |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 1344 | child = radix_tree_node_alloc(gfp, node, root, |
Matthew Wilcox | e8de434 | 2016-12-14 15:09:31 -0800 | [diff] [blame] | 1345 | node->shift - RADIX_TREE_MAP_SHIFT, |
| 1346 | offset, 0, 0); |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1347 | if (!child) |
| 1348 | goto nomem; |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1349 | if (node != parent) { |
| 1350 | node->count++; |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 1351 | rcu_assign_pointer(node->slots[offset], |
| 1352 | node_to_entry(child)); |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1353 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 1354 | if (tags & (1 << tag)) |
| 1355 | tag_set(node, tag, offset); |
| 1356 | } |
| 1357 | |
| 1358 | node = child; |
| 1359 | offset = 0; |
| 1360 | continue; |
| 1361 | } |
| 1362 | |
| 1363 | n = insert_entries(node, &node->slots[offset], |
| 1364 | RADIX_TREE_RETRY, order, false); |
| 1365 | BUG_ON(n > RADIX_TREE_MAP_SIZE); |
| 1366 | |
| 1367 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 1368 | if (tags & (1 << tag)) |
| 1369 | tag_set(node, tag, offset); |
| 1370 | offset += n; |
| 1371 | |
| 1372 | while (offset == RADIX_TREE_MAP_SIZE) { |
| 1373 | if (node == parent) |
| 1374 | break; |
| 1375 | offset = node->offset; |
| 1376 | child = node; |
| 1377 | node = node->parent; |
| 1378 | rcu_assign_pointer(node->slots[offset], |
| 1379 | node_to_entry(child)); |
| 1380 | offset++; |
| 1381 | } |
| 1382 | if ((node == parent) && (offset == end)) |
| 1383 | return 0; |
| 1384 | } |
| 1385 | |
| 1386 | nomem: |
| 1387 | /* Shouldn't happen; did user forget to preload? */ |
| 1388 | /* TODO: free all the allocated nodes */ |
| 1389 | WARN_ON(1); |
| 1390 | return -ENOMEM; |
| 1391 | } |
Matthew Wilcox | 175542f | 2016-12-14 15:08:58 -0800 | [diff] [blame] | 1392 | #endif |
| 1393 | |
Matthew Wilcox | 30b888b | 2017-01-28 09:55:20 -0500 | [diff] [blame] | 1394 | static void node_tag_set(struct radix_tree_root *root, |
| 1395 | struct radix_tree_node *node, |
| 1396 | unsigned int tag, unsigned int offset) |
| 1397 | { |
| 1398 | while (node) { |
| 1399 | if (tag_get(node, tag, offset)) |
| 1400 | return; |
| 1401 | tag_set(node, tag, offset); |
| 1402 | offset = node->offset; |
| 1403 | node = node->parent; |
| 1404 | } |
| 1405 | |
| 1406 | if (!root_tag_get(root, tag)) |
| 1407 | root_tag_set(root, tag); |
| 1408 | } |
| 1409 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | /** |
| 1411 | * radix_tree_tag_set - set a tag on a radix tree node |
| 1412 | * @root: radix tree root |
| 1413 | * @index: index key |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1414 | * @tag: tag index |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | * |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1416 | * Set the search tag (which must be < RADIX_TREE_MAX_TAGS) |
| 1417 | * corresponding to @index in the radix tree. From |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | * the root all the way down to the leaf node. |
| 1419 | * |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1420 | * Returns the address of the tagged item. Setting a tag on a not-present |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1421 | * item is a bug. |
| 1422 | */ |
| 1423 | void *radix_tree_tag_set(struct radix_tree_root *root, |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1424 | unsigned long index, unsigned int tag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | { |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1426 | struct radix_tree_node *node, *parent; |
| 1427 | unsigned long maxindex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1429 | radix_tree_load_root(root, &node, &maxindex); |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1430 | BUG_ON(index > maxindex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1432 | while (radix_tree_is_internal_node(node)) { |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1433 | unsigned offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 1435 | parent = entry_to_node(node); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1436 | offset = radix_tree_descend(parent, &node, index); |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1437 | BUG_ON(!node); |
| 1438 | |
| 1439 | if (!tag_get(parent, tag, offset)) |
| 1440 | tag_set(parent, tag, offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | } |
| 1442 | |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1443 | /* set the root's tag bit */ |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1444 | if (!root_tag_get(root, tag)) |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1445 | root_tag_set(root, tag); |
| 1446 | |
Ross Zwisler | fb96990 | 2016-05-20 17:02:32 -0700 | [diff] [blame] | 1447 | return node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1448 | } |
| 1449 | EXPORT_SYMBOL(radix_tree_tag_set); |
| 1450 | |
Matthew Wilcox | 30b888b | 2017-01-28 09:55:20 -0500 | [diff] [blame] | 1451 | /** |
| 1452 | * radix_tree_iter_tag_set - set a tag on the current iterator entry |
| 1453 | * @root: radix tree root |
| 1454 | * @iter: iterator state |
| 1455 | * @tag: tag to set |
| 1456 | */ |
| 1457 | void radix_tree_iter_tag_set(struct radix_tree_root *root, |
| 1458 | const struct radix_tree_iter *iter, unsigned int tag) |
| 1459 | { |
| 1460 | node_tag_set(root, iter->node, tag, iter_offset(iter)); |
| 1461 | } |
| 1462 | |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 1463 | static void node_tag_clear(struct radix_tree_root *root, |
| 1464 | struct radix_tree_node *node, |
| 1465 | unsigned int tag, unsigned int offset) |
| 1466 | { |
| 1467 | while (node) { |
| 1468 | if (!tag_get(node, tag, offset)) |
| 1469 | return; |
| 1470 | tag_clear(node, tag, offset); |
| 1471 | if (any_tag_set(node, tag)) |
| 1472 | return; |
| 1473 | |
| 1474 | offset = node->offset; |
| 1475 | node = node->parent; |
| 1476 | } |
| 1477 | |
| 1478 | /* clear the root's tag bit */ |
| 1479 | if (root_tag_get(root, tag)) |
| 1480 | root_tag_clear(root, tag); |
| 1481 | } |
| 1482 | |
Matthew Wilcox | 268f42d | 2016-12-14 15:08:55 -0800 | [diff] [blame] | 1483 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | * radix_tree_tag_clear - clear a tag on a radix tree node |
| 1485 | * @root: radix tree root |
| 1486 | * @index: index key |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1487 | * @tag: tag index |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | * |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1489 | * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS) |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1490 | * corresponding to @index in the radix tree. If this causes |
| 1491 | * the leaf node to have no tags set then clear the tag in the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | * next-to-leaf node, etc. |
| 1493 | * |
| 1494 | * Returns the address of the tagged item on success, else NULL. ie: |
| 1495 | * has the same return value and semantics as radix_tree_lookup(). |
| 1496 | */ |
| 1497 | void *radix_tree_tag_clear(struct radix_tree_root *root, |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1498 | unsigned long index, unsigned int tag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | { |
Ross Zwisler | 00f47b5 | 2016-05-20 17:02:35 -0700 | [diff] [blame] | 1500 | struct radix_tree_node *node, *parent; |
| 1501 | unsigned long maxindex; |
Hugh Dickins | e2bdb93 | 2012-01-12 17:20:41 -0800 | [diff] [blame] | 1502 | int uninitialized_var(offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1504 | radix_tree_load_root(root, &node, &maxindex); |
Ross Zwisler | 00f47b5 | 2016-05-20 17:02:35 -0700 | [diff] [blame] | 1505 | if (index > maxindex) |
| 1506 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | |
Ross Zwisler | 00f47b5 | 2016-05-20 17:02:35 -0700 | [diff] [blame] | 1508 | parent = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1509 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1510 | while (radix_tree_is_internal_node(node)) { |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 1511 | parent = entry_to_node(node); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1512 | offset = radix_tree_descend(parent, &node, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | } |
| 1514 | |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 1515 | if (node) |
| 1516 | node_tag_clear(root, parent, tag, offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1517 | |
Ross Zwisler | 00f47b5 | 2016-05-20 17:02:35 -0700 | [diff] [blame] | 1518 | return node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | } |
| 1520 | EXPORT_SYMBOL(radix_tree_tag_clear); |
| 1521 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | /** |
Matthew Wilcox | 30b888b | 2017-01-28 09:55:20 -0500 | [diff] [blame] | 1523 | * radix_tree_iter_tag_clear - clear a tag on the current iterator entry |
| 1524 | * @root: radix tree root |
| 1525 | * @iter: iterator state |
| 1526 | * @tag: tag to clear |
| 1527 | */ |
| 1528 | void radix_tree_iter_tag_clear(struct radix_tree_root *root, |
| 1529 | const struct radix_tree_iter *iter, unsigned int tag) |
| 1530 | { |
| 1531 | node_tag_clear(root, iter->node, tag, iter_offset(iter)); |
| 1532 | } |
| 1533 | |
| 1534 | /** |
Marcelo Tosatti | 32605a1 | 2005-09-06 15:16:48 -0700 | [diff] [blame] | 1535 | * radix_tree_tag_get - get a tag on a radix tree node |
| 1536 | * @root: radix tree root |
| 1537 | * @index: index key |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1538 | * @tag: tag index (< RADIX_TREE_MAX_TAGS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | * |
Marcelo Tosatti | 32605a1 | 2005-09-06 15:16:48 -0700 | [diff] [blame] | 1540 | * Return values: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | * |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1542 | * 0: tag not present or not set |
| 1543 | * 1: tag set |
David Howells | ce82653 | 2010-04-06 22:36:20 +0100 | [diff] [blame] | 1544 | * |
| 1545 | * Note that the return value of this function may not be relied on, even if |
| 1546 | * the RCU lock is held, unless tag modification and node deletion are excluded |
| 1547 | * from concurrency. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1548 | */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1549 | int radix_tree_tag_get(const struct radix_tree_root *root, |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1550 | unsigned long index, unsigned int tag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1551 | { |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1552 | struct radix_tree_node *node, *parent; |
| 1553 | unsigned long maxindex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1554 | |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1555 | if (!root_tag_get(root, tag)) |
| 1556 | return 0; |
| 1557 | |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1558 | radix_tree_load_root(root, &node, &maxindex); |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1559 | if (index > maxindex) |
| 1560 | return 0; |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1561 | |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1562 | while (radix_tree_is_internal_node(node)) { |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1563 | unsigned offset; |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1564 | |
Matthew Wilcox | 4dd6c09 | 2016-05-20 17:03:27 -0700 | [diff] [blame] | 1565 | parent = entry_to_node(node); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1566 | offset = radix_tree_descend(parent, &node, index); |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1567 | |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1568 | if (!tag_get(parent, tag, offset)) |
| 1569 | return 0; |
| 1570 | if (node == RADIX_TREE_RETRY) |
| 1571 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | } |
Ross Zwisler | 4589ba6 | 2016-05-20 17:02:38 -0700 | [diff] [blame] | 1573 | |
| 1574 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | } |
| 1576 | EXPORT_SYMBOL(radix_tree_tag_get); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1577 | |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1578 | static inline void __set_iter_shift(struct radix_tree_iter *iter, |
| 1579 | unsigned int shift) |
| 1580 | { |
| 1581 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
| 1582 | iter->shift = shift; |
| 1583 | #endif |
| 1584 | } |
| 1585 | |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1586 | /* Construct iter->tags bit-mask from node->tags[tag] array */ |
| 1587 | static void set_iter_tags(struct radix_tree_iter *iter, |
| 1588 | struct radix_tree_node *node, unsigned offset, |
| 1589 | unsigned tag) |
| 1590 | { |
| 1591 | unsigned tag_long = offset / BITS_PER_LONG; |
| 1592 | unsigned tag_bit = offset % BITS_PER_LONG; |
| 1593 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1594 | if (!node) { |
| 1595 | iter->tags = 1; |
| 1596 | return; |
| 1597 | } |
| 1598 | |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1599 | iter->tags = node->tags[tag][tag_long] >> tag_bit; |
| 1600 | |
| 1601 | /* This never happens if RADIX_TREE_TAG_LONGS == 1 */ |
| 1602 | if (tag_long < RADIX_TREE_TAG_LONGS - 1) { |
| 1603 | /* Pick tags from next element */ |
| 1604 | if (tag_bit) |
| 1605 | iter->tags |= node->tags[tag][tag_long + 1] << |
| 1606 | (BITS_PER_LONG - tag_bit); |
| 1607 | /* Clip chunk size, here only BITS_PER_LONG tags */ |
| 1608 | iter->next_index = __radix_tree_iter_add(iter, BITS_PER_LONG); |
| 1609 | } |
| 1610 | } |
| 1611 | |
| 1612 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1613 | static void __rcu **skip_siblings(struct radix_tree_node **nodep, |
| 1614 | void __rcu **slot, struct radix_tree_iter *iter) |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1615 | { |
| 1616 | void *sib = node_to_entry(slot - 1); |
| 1617 | |
| 1618 | while (iter->index < iter->next_index) { |
| 1619 | *nodep = rcu_dereference_raw(*slot); |
| 1620 | if (*nodep && *nodep != sib) |
| 1621 | return slot; |
| 1622 | slot++; |
| 1623 | iter->index = __radix_tree_iter_add(iter, 1); |
| 1624 | iter->tags >>= 1; |
| 1625 | } |
| 1626 | |
| 1627 | *nodep = NULL; |
| 1628 | return NULL; |
| 1629 | } |
| 1630 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1631 | void __rcu **__radix_tree_next_slot(void __rcu **slot, |
| 1632 | struct radix_tree_iter *iter, unsigned flags) |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1633 | { |
| 1634 | unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; |
| 1635 | struct radix_tree_node *node = rcu_dereference_raw(*slot); |
| 1636 | |
| 1637 | slot = skip_siblings(&node, slot, iter); |
| 1638 | |
| 1639 | while (radix_tree_is_internal_node(node)) { |
| 1640 | unsigned offset; |
| 1641 | unsigned long next_index; |
| 1642 | |
| 1643 | if (node == RADIX_TREE_RETRY) |
| 1644 | return slot; |
| 1645 | node = entry_to_node(node); |
Matthew Wilcox | 268f42d | 2016-12-14 15:08:55 -0800 | [diff] [blame] | 1646 | iter->node = node; |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1647 | iter->shift = node->shift; |
| 1648 | |
| 1649 | if (flags & RADIX_TREE_ITER_TAGGED) { |
| 1650 | offset = radix_tree_find_next_bit(node, tag, 0); |
| 1651 | if (offset == RADIX_TREE_MAP_SIZE) |
| 1652 | return NULL; |
| 1653 | slot = &node->slots[offset]; |
| 1654 | iter->index = __radix_tree_iter_add(iter, offset); |
| 1655 | set_iter_tags(iter, node, offset, tag); |
| 1656 | node = rcu_dereference_raw(*slot); |
| 1657 | } else { |
| 1658 | offset = 0; |
| 1659 | slot = &node->slots[0]; |
| 1660 | for (;;) { |
| 1661 | node = rcu_dereference_raw(*slot); |
| 1662 | if (node) |
| 1663 | break; |
| 1664 | slot++; |
| 1665 | offset++; |
| 1666 | if (offset == RADIX_TREE_MAP_SIZE) |
| 1667 | return NULL; |
| 1668 | } |
| 1669 | iter->index = __radix_tree_iter_add(iter, offset); |
| 1670 | } |
| 1671 | if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0)) |
| 1672 | goto none; |
| 1673 | next_index = (iter->index | shift_maxindex(iter->shift)) + 1; |
| 1674 | if (next_index < iter->next_index) |
| 1675 | iter->next_index = next_index; |
| 1676 | } |
| 1677 | |
| 1678 | return slot; |
| 1679 | none: |
| 1680 | iter->next_index = 0; |
| 1681 | return NULL; |
| 1682 | } |
| 1683 | EXPORT_SYMBOL(__radix_tree_next_slot); |
| 1684 | #else |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1685 | static void __rcu **skip_siblings(struct radix_tree_node **nodep, |
| 1686 | void __rcu **slot, struct radix_tree_iter *iter) |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1687 | { |
| 1688 | return slot; |
| 1689 | } |
| 1690 | #endif |
| 1691 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1692 | void __rcu **radix_tree_iter_resume(void __rcu **slot, |
| 1693 | struct radix_tree_iter *iter) |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1694 | { |
| 1695 | struct radix_tree_node *node; |
| 1696 | |
| 1697 | slot++; |
| 1698 | iter->index = __radix_tree_iter_add(iter, 1); |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1699 | skip_siblings(&node, slot, iter); |
| 1700 | iter->next_index = iter->index; |
| 1701 | iter->tags = 0; |
| 1702 | return NULL; |
| 1703 | } |
| 1704 | EXPORT_SYMBOL(radix_tree_iter_resume); |
| 1705 | |
Fengguang Wu | 6df8ba4 | 2007-10-16 01:24:33 -0700 | [diff] [blame] | 1706 | /** |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1707 | * radix_tree_next_chunk - find next chunk of slots for iteration |
| 1708 | * |
| 1709 | * @root: radix tree root |
| 1710 | * @iter: iterator state |
| 1711 | * @flags: RADIX_TREE_ITER_* flags and tag index |
| 1712 | * Returns: pointer to chunk first slot, or NULL if iteration is over |
| 1713 | */ |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1714 | void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root, |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1715 | struct radix_tree_iter *iter, unsigned flags) |
| 1716 | { |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1717 | unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1718 | struct radix_tree_node *node, *child; |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1719 | unsigned long index, offset, maxindex; |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1720 | |
| 1721 | if ((flags & RADIX_TREE_ITER_TAGGED) && !root_tag_get(root, tag)) |
| 1722 | return NULL; |
| 1723 | |
| 1724 | /* |
| 1725 | * Catch next_index overflow after ~0UL. iter->index never overflows |
| 1726 | * during iterating; it can be zero only at the beginning. |
| 1727 | * And we cannot overflow iter->next_index in a single step, |
| 1728 | * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG. |
Konstantin Khlebnikov | fffaee3 | 2012-06-05 21:36:33 +0400 | [diff] [blame] | 1729 | * |
| 1730 | * This condition also used by radix_tree_next_slot() to stop |
Matthew Wilcox | 91b9677c | 2016-12-14 15:08:31 -0800 | [diff] [blame] | 1731 | * contiguous iterating, and forbid switching to the next chunk. |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1732 | */ |
| 1733 | index = iter->next_index; |
| 1734 | if (!index && iter->index) |
| 1735 | return NULL; |
| 1736 | |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1737 | restart: |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1738 | radix_tree_load_root(root, &child, &maxindex); |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1739 | if (index > maxindex) |
| 1740 | return NULL; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1741 | if (!child) |
| 1742 | return NULL; |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1743 | |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1744 | if (!radix_tree_is_internal_node(child)) { |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1745 | /* Single-slot tree */ |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1746 | iter->index = index; |
| 1747 | iter->next_index = maxindex + 1; |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1748 | iter->tags = 1; |
Matthew Wilcox | 268f42d | 2016-12-14 15:08:55 -0800 | [diff] [blame] | 1749 | iter->node = NULL; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1750 | __set_iter_shift(iter, 0); |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1751 | return (void __rcu **)&root->rnode; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1752 | } |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1753 | |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1754 | do { |
| 1755 | node = entry_to_node(child); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1756 | offset = radix_tree_descend(node, &child, index); |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1757 | |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1758 | if ((flags & RADIX_TREE_ITER_TAGGED) ? |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1759 | !tag_get(node, tag, offset) : !child) { |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1760 | /* Hole detected */ |
| 1761 | if (flags & RADIX_TREE_ITER_CONTIG) |
| 1762 | return NULL; |
| 1763 | |
| 1764 | if (flags & RADIX_TREE_ITER_TAGGED) |
Matthew Wilcox | bc412fc | 2016-12-14 15:08:40 -0800 | [diff] [blame] | 1765 | offset = radix_tree_find_next_bit(node, tag, |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1766 | offset + 1); |
| 1767 | else |
| 1768 | while (++offset < RADIX_TREE_MAP_SIZE) { |
Matthew Wilcox | 12320d0 | 2017-02-13 15:22:48 -0500 | [diff] [blame] | 1769 | void *slot = rcu_dereference_raw( |
| 1770 | node->slots[offset]); |
Ross Zwisler | 21ef533 | 2016-05-20 17:02:26 -0700 | [diff] [blame] | 1771 | if (is_sibling_entry(node, slot)) |
| 1772 | continue; |
| 1773 | if (slot) |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1774 | break; |
| 1775 | } |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1776 | index &= ~node_maxindex(node); |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1777 | index += offset << node->shift; |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1778 | /* Overflow after ~0UL */ |
| 1779 | if (!index) |
| 1780 | return NULL; |
| 1781 | if (offset == RADIX_TREE_MAP_SIZE) |
| 1782 | goto restart; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1783 | child = rcu_dereference_raw(node->slots[offset]); |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1784 | } |
| 1785 | |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1786 | if (!child) |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1787 | goto restart; |
Matthew Wilcox | e157b55 | 2016-12-14 15:09:01 -0800 | [diff] [blame] | 1788 | if (child == RADIX_TREE_RETRY) |
| 1789 | break; |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1790 | } while (radix_tree_is_internal_node(child)); |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1791 | |
| 1792 | /* Update the iterator state */ |
Matthew Wilcox | 8c1244d | 2016-05-20 17:03:36 -0700 | [diff] [blame] | 1793 | iter->index = (index &~ node_maxindex(node)) | (offset << node->shift); |
| 1794 | iter->next_index = (index | node_maxindex(node)) + 1; |
Matthew Wilcox | 268f42d | 2016-12-14 15:08:55 -0800 | [diff] [blame] | 1795 | iter->node = node; |
Matthew Wilcox | 9e85d81 | 2016-05-20 17:03:48 -0700 | [diff] [blame] | 1796 | __set_iter_shift(iter, node->shift); |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1797 | |
Matthew Wilcox | 148deab | 2016-12-14 15:08:49 -0800 | [diff] [blame] | 1798 | if (flags & RADIX_TREE_ITER_TAGGED) |
| 1799 | set_iter_tags(iter, node, offset, tag); |
Konstantin Khlebnikov | 78c1d78 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1800 | |
| 1801 | return node->slots + offset; |
| 1802 | } |
| 1803 | EXPORT_SYMBOL(radix_tree_next_chunk); |
| 1804 | |
| 1805 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1806 | * radix_tree_gang_lookup - perform multiple lookup on a radix tree |
| 1807 | * @root: radix tree root |
| 1808 | * @results: where the results of the lookup are placed |
| 1809 | * @first_index: start the lookup from this key |
| 1810 | * @max_items: place up to this many items at *results |
| 1811 | * |
| 1812 | * Performs an index-ascending scan of the tree for present items. Places |
| 1813 | * them at *@results and returns the number of items which were placed at |
| 1814 | * *@results. |
| 1815 | * |
| 1816 | * The implementation is naive. |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1817 | * |
| 1818 | * Like radix_tree_lookup, radix_tree_gang_lookup may be called under |
| 1819 | * rcu_read_lock. In this case, rather than the returned results being |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 1820 | * an atomic snapshot of the tree at a single point in time, the |
| 1821 | * semantics of an RCU protected gang lookup are as though multiple |
| 1822 | * radix_tree_lookups have been issued in individual locks, and results |
| 1823 | * stored in 'results'. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1824 | */ |
| 1825 | unsigned int |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1826 | radix_tree_gang_lookup(const struct radix_tree_root *root, void **results, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | unsigned long first_index, unsigned int max_items) |
| 1828 | { |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1829 | struct radix_tree_iter iter; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1830 | void __rcu **slot; |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1831 | unsigned int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1832 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1833 | if (unlikely(!max_items)) |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1834 | return 0; |
| 1835 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1836 | radix_tree_for_each_slot(slot, root, &iter, first_index) { |
Matthew Wilcox | 46437f9 | 2016-02-02 16:57:52 -0800 | [diff] [blame] | 1837 | results[ret] = rcu_dereference_raw(*slot); |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1838 | if (!results[ret]) |
| 1839 | continue; |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1840 | if (radix_tree_is_internal_node(results[ret])) { |
Matthew Wilcox | 46437f9 | 2016-02-02 16:57:52 -0800 | [diff] [blame] | 1841 | slot = radix_tree_iter_retry(&iter); |
| 1842 | continue; |
| 1843 | } |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1844 | if (++ret == max_items) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1846 | } |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1848 | return ret; |
| 1849 | } |
| 1850 | EXPORT_SYMBOL(radix_tree_gang_lookup); |
| 1851 | |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1852 | /** |
| 1853 | * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree |
| 1854 | * @root: radix tree root |
| 1855 | * @results: where the results of the lookup are placed |
Hugh Dickins | 6328650 | 2011-08-03 16:21:18 -0700 | [diff] [blame] | 1856 | * @indices: where their indices should be placed (but usually NULL) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1857 | * @first_index: start the lookup from this key |
| 1858 | * @max_items: place up to this many items at *results |
| 1859 | * |
| 1860 | * Performs an index-ascending scan of the tree for present items. Places |
| 1861 | * their slots at *@results and returns the number of items which were |
| 1862 | * placed at *@results. |
| 1863 | * |
| 1864 | * The implementation is naive. |
| 1865 | * |
| 1866 | * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must |
| 1867 | * be dereferenced with radix_tree_deref_slot, and if using only RCU |
| 1868 | * protection, radix_tree_deref_slot may fail requiring a retry. |
| 1869 | */ |
| 1870 | unsigned int |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1871 | radix_tree_gang_lookup_slot(const struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1872 | void __rcu ***results, unsigned long *indices, |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1873 | unsigned long first_index, unsigned int max_items) |
| 1874 | { |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1875 | struct radix_tree_iter iter; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1876 | void __rcu **slot; |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1877 | unsigned int ret = 0; |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1878 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1879 | if (unlikely(!max_items)) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1880 | return 0; |
| 1881 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1882 | radix_tree_for_each_slot(slot, root, &iter, first_index) { |
| 1883 | results[ret] = slot; |
Hugh Dickins | 6328650 | 2011-08-03 16:21:18 -0700 | [diff] [blame] | 1884 | if (indices) |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1885 | indices[ret] = iter.index; |
| 1886 | if (++ret == max_items) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1887 | break; |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1888 | } |
| 1889 | |
| 1890 | return ret; |
| 1891 | } |
| 1892 | EXPORT_SYMBOL(radix_tree_gang_lookup_slot); |
| 1893 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | /** |
| 1895 | * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree |
| 1896 | * based on a tag |
| 1897 | * @root: radix tree root |
| 1898 | * @results: where the results of the lookup are placed |
| 1899 | * @first_index: start the lookup from this key |
| 1900 | * @max_items: place up to this many items at *results |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1901 | * @tag: the tag index (< RADIX_TREE_MAX_TAGS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | * |
| 1903 | * Performs an index-ascending scan of the tree for present items which |
| 1904 | * have the tag indexed by @tag set. Places the items at *@results and |
| 1905 | * returns the number of items which were placed at *@results. |
| 1906 | */ |
| 1907 | unsigned int |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1908 | radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results, |
Jonathan Corbet | daff89f | 2006-03-25 03:08:05 -0800 | [diff] [blame] | 1909 | unsigned long first_index, unsigned int max_items, |
| 1910 | unsigned int tag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1911 | { |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1912 | struct radix_tree_iter iter; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1913 | void __rcu **slot; |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1914 | unsigned int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1915 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1916 | if (unlikely(!max_items)) |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 1917 | return 0; |
| 1918 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1919 | radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) { |
Matthew Wilcox | 46437f9 | 2016-02-02 16:57:52 -0800 | [diff] [blame] | 1920 | results[ret] = rcu_dereference_raw(*slot); |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1921 | if (!results[ret]) |
| 1922 | continue; |
Matthew Wilcox | b194d16 | 2016-05-20 17:03:30 -0700 | [diff] [blame] | 1923 | if (radix_tree_is_internal_node(results[ret])) { |
Matthew Wilcox | 46437f9 | 2016-02-02 16:57:52 -0800 | [diff] [blame] | 1924 | slot = radix_tree_iter_retry(&iter); |
| 1925 | continue; |
| 1926 | } |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1927 | if (++ret == max_items) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1928 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1929 | } |
Nick Piggin | 7cf9c2c | 2006-12-06 20:33:44 -0800 | [diff] [blame] | 1930 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1931 | return ret; |
| 1932 | } |
| 1933 | EXPORT_SYMBOL(radix_tree_gang_lookup_tag); |
| 1934 | |
| 1935 | /** |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1936 | * radix_tree_gang_lookup_tag_slot - perform multiple slot lookup on a |
| 1937 | * radix tree based on a tag |
| 1938 | * @root: radix tree root |
| 1939 | * @results: where the results of the lookup are placed |
| 1940 | * @first_index: start the lookup from this key |
| 1941 | * @max_items: place up to this many items at *results |
| 1942 | * @tag: the tag index (< RADIX_TREE_MAX_TAGS) |
| 1943 | * |
| 1944 | * Performs an index-ascending scan of the tree for present items which |
| 1945 | * have the tag indexed by @tag set. Places the slots at *@results and |
| 1946 | * returns the number of slots which were placed at *@results. |
| 1947 | */ |
| 1948 | unsigned int |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1949 | radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1950 | void __rcu ***results, unsigned long first_index, |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 1951 | unsigned int max_items, unsigned int tag) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1952 | { |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1953 | struct radix_tree_iter iter; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1954 | void __rcu **slot; |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1955 | unsigned int ret = 0; |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1956 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1957 | if (unlikely(!max_items)) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1958 | return 0; |
| 1959 | |
Konstantin Khlebnikov | cebbd29 | 2012-03-28 14:42:53 -0700 | [diff] [blame] | 1960 | radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) { |
| 1961 | results[ret] = slot; |
| 1962 | if (++ret == max_items) |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1963 | break; |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1964 | } |
| 1965 | |
| 1966 | return ret; |
| 1967 | } |
| 1968 | EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot); |
| 1969 | |
Nick Piggin | 47feff2 | 2008-07-25 19:45:29 -0700 | [diff] [blame] | 1970 | /** |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1971 | * __radix_tree_delete_node - try to free node after clearing a slot |
| 1972 | * @root: radix tree root |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1973 | * @node: node containing @index |
Johannes Weiner | ea07b86 | 2017-01-06 19:21:43 -0500 | [diff] [blame] | 1974 | * @update_node: callback for changing leaf nodes |
| 1975 | * @private: private data to pass to @update_node |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1976 | * |
| 1977 | * After clearing the slot at @index in @node from radix tree |
| 1978 | * rooted at @root, call this function to attempt freeing the |
| 1979 | * node and shrinking the tree. |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1980 | */ |
Johannes Weiner | 14b4687 | 2016-12-12 16:43:52 -0800 | [diff] [blame] | 1981 | void __radix_tree_delete_node(struct radix_tree_root *root, |
Johannes Weiner | ea07b86 | 2017-01-06 19:21:43 -0500 | [diff] [blame] | 1982 | struct radix_tree_node *node, |
| 1983 | radix_tree_update_node_t update_node, |
| 1984 | void *private) |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1985 | { |
Johannes Weiner | ea07b86 | 2017-01-06 19:21:43 -0500 | [diff] [blame] | 1986 | delete_node(root, node, update_node, private); |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 1987 | } |
| 1988 | |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 1989 | static bool __radix_tree_delete(struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 1990 | struct radix_tree_node *node, void __rcu **slot) |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 1991 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1992 | void *old = rcu_dereference_raw(*slot); |
| 1993 | int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0; |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 1994 | unsigned offset = get_slot_offset(node, slot); |
| 1995 | int tag; |
| 1996 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 1997 | if (is_idr(root)) |
| 1998 | node_tag_set(root, node, IDR_FREE, offset); |
| 1999 | else |
| 2000 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 2001 | node_tag_clear(root, node, tag, offset); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2002 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2003 | replace_slot(slot, NULL, node, -1, exceptional); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2004 | return node && delete_node(root, node, NULL, NULL); |
| 2005 | } |
| 2006 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2007 | /** |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2008 | * radix_tree_iter_delete - delete the entry at this iterator position |
| 2009 | * @root: radix tree root |
| 2010 | * @iter: iterator state |
| 2011 | * @slot: pointer to slot |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2012 | * |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2013 | * Delete the entry at the position currently pointed to by the iterator. |
| 2014 | * This may result in the current node being freed; if it is, the iterator |
| 2015 | * is advanced so that it will not reference the freed memory. This |
| 2016 | * function may be called without any locking if there are no other threads |
| 2017 | * which can access this tree. |
| 2018 | */ |
| 2019 | void radix_tree_iter_delete(struct radix_tree_root *root, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 2020 | struct radix_tree_iter *iter, void __rcu **slot) |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2021 | { |
| 2022 | if (__radix_tree_delete(root, iter->node, slot)) |
| 2023 | iter->index = iter->next_index; |
| 2024 | } |
Chris Wilson | d1b48c1 | 2017-08-16 09:52:08 +0100 | [diff] [blame^] | 2025 | EXPORT_SYMBOL(radix_tree_iter_delete); |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2026 | |
| 2027 | /** |
| 2028 | * radix_tree_delete_item - delete an item from a radix tree |
| 2029 | * @root: radix tree root |
| 2030 | * @index: index key |
| 2031 | * @item: expected item |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2032 | * |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2033 | * Remove @item at @index from the radix tree rooted at @root. |
| 2034 | * |
| 2035 | * Return: the deleted entry, or %NULL if it was not present |
| 2036 | * or the entry at the given @index was not @item. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | */ |
Johannes Weiner | 53c59f2 | 2014-04-03 14:47:39 -0700 | [diff] [blame] | 2038 | void *radix_tree_delete_item(struct radix_tree_root *root, |
| 2039 | unsigned long index, void *item) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2040 | { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2041 | struct radix_tree_node *node = NULL; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 2042 | void __rcu **slot; |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2043 | void *entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2044 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2045 | entry = __radix_tree_lookup(root, index, &node, &slot); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2046 | if (!entry && (!is_idr(root) || node_tag_get(root, node, IDR_FREE, |
| 2047 | get_slot_offset(node, slot)))) |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2048 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2050 | if (item && entry != item) |
| 2051 | return NULL; |
| 2052 | |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2053 | __radix_tree_delete(root, node, slot); |
Christoph Lameter | 201b626 | 2005-09-06 15:16:46 -0700 | [diff] [blame] | 2054 | |
Johannes Weiner | 139e561 | 2014-04-03 14:47:54 -0700 | [diff] [blame] | 2055 | return entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2056 | } |
Johannes Weiner | 53c59f2 | 2014-04-03 14:47:39 -0700 | [diff] [blame] | 2057 | EXPORT_SYMBOL(radix_tree_delete_item); |
| 2058 | |
| 2059 | /** |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2060 | * radix_tree_delete - delete an entry from a radix tree |
| 2061 | * @root: radix tree root |
| 2062 | * @index: index key |
Johannes Weiner | 53c59f2 | 2014-04-03 14:47:39 -0700 | [diff] [blame] | 2063 | * |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2064 | * Remove the entry at @index from the radix tree rooted at @root. |
Johannes Weiner | 53c59f2 | 2014-04-03 14:47:39 -0700 | [diff] [blame] | 2065 | * |
Matthew Wilcox | 0ac398e | 2017-01-28 09:56:22 -0500 | [diff] [blame] | 2066 | * Return: The deleted entry, or %NULL if it was not present. |
Johannes Weiner | 53c59f2 | 2014-04-03 14:47:39 -0700 | [diff] [blame] | 2067 | */ |
| 2068 | void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) |
| 2069 | { |
| 2070 | return radix_tree_delete_item(root, index, NULL); |
| 2071 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2072 | EXPORT_SYMBOL(radix_tree_delete); |
| 2073 | |
Johannes Weiner | d3798ae | 2016-10-04 22:02:08 +0200 | [diff] [blame] | 2074 | void radix_tree_clear_tags(struct radix_tree_root *root, |
| 2075 | struct radix_tree_node *node, |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 2076 | void __rcu **slot) |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 2077 | { |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 2078 | if (node) { |
| 2079 | unsigned int tag, offset = get_slot_offset(node, slot); |
| 2080 | for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) |
| 2081 | node_tag_clear(root, node, tag, offset); |
| 2082 | } else { |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2083 | root_tag_clear_all(root); |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 2084 | } |
Matthew Wilcox | d604c32 | 2016-05-20 17:03:45 -0700 | [diff] [blame] | 2085 | } |
| 2086 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2087 | /** |
| 2088 | * radix_tree_tagged - test whether any items in the tree are tagged |
| 2089 | * @root: radix tree root |
| 2090 | * @tag: tag to test |
| 2091 | */ |
Matthew Wilcox | 35534c8 | 2016-12-19 17:43:19 -0500 | [diff] [blame] | 2092 | int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2093 | { |
Nick Piggin | 612d6c1 | 2006-06-23 02:03:22 -0700 | [diff] [blame] | 2094 | return root_tag_get(root, tag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2095 | } |
| 2096 | EXPORT_SYMBOL(radix_tree_tagged); |
| 2097 | |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2098 | /** |
| 2099 | * idr_preload - preload for idr_alloc() |
| 2100 | * @gfp_mask: allocation mask to use for preloading |
| 2101 | * |
| 2102 | * Preallocate memory to use for the next call to idr_alloc(). This function |
| 2103 | * returns with preemption disabled. It will be enabled by idr_preload_end(). |
| 2104 | */ |
| 2105 | void idr_preload(gfp_t gfp_mask) |
| 2106 | { |
| 2107 | __radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE); |
| 2108 | } |
| 2109 | EXPORT_SYMBOL(idr_preload); |
| 2110 | |
Matthew Wilcox | 7ad3d4d | 2016-12-16 11:55:56 -0500 | [diff] [blame] | 2111 | /** |
| 2112 | * ida_pre_get - reserve resources for ida allocation |
| 2113 | * @ida: ida handle |
| 2114 | * @gfp: memory allocation flags |
| 2115 | * |
| 2116 | * This function should be called before calling ida_get_new_above(). If it |
| 2117 | * is unable to allocate memory, it will return %0. On success, it returns %1. |
| 2118 | */ |
| 2119 | int ida_pre_get(struct ida *ida, gfp_t gfp) |
| 2120 | { |
| 2121 | __radix_tree_preload(gfp, IDA_PRELOAD_SIZE); |
| 2122 | /* |
| 2123 | * The IDA API has no preload_end() equivalent. Instead, |
| 2124 | * ida_get_new() can return -EAGAIN, prompting the caller |
| 2125 | * to return to the ida_pre_get() step. |
| 2126 | */ |
| 2127 | preempt_enable(); |
| 2128 | |
| 2129 | if (!this_cpu_read(ida_bitmap)) { |
| 2130 | struct ida_bitmap *bitmap = kmalloc(sizeof(*bitmap), gfp); |
| 2131 | if (!bitmap) |
| 2132 | return 0; |
Matthew Wilcox | 4ecd954 | 2017-03-03 12:16:10 -0500 | [diff] [blame] | 2133 | if (this_cpu_cmpxchg(ida_bitmap, NULL, bitmap)) |
| 2134 | kfree(bitmap); |
Matthew Wilcox | 7ad3d4d | 2016-12-16 11:55:56 -0500 | [diff] [blame] | 2135 | } |
| 2136 | |
| 2137 | return 1; |
| 2138 | } |
| 2139 | EXPORT_SYMBOL(ida_pre_get); |
| 2140 | |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 2141 | void __rcu **idr_get_free(struct radix_tree_root *root, |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2142 | struct radix_tree_iter *iter, gfp_t gfp, int end) |
| 2143 | { |
| 2144 | struct radix_tree_node *node = NULL, *child; |
Matthew Wilcox | d7b6272 | 2017-02-13 15:58:24 -0500 | [diff] [blame] | 2145 | void __rcu **slot = (void __rcu **)&root->rnode; |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2146 | unsigned long maxindex, start = iter->next_index; |
| 2147 | unsigned long max = end > 0 ? end - 1 : INT_MAX; |
| 2148 | unsigned int shift, offset = 0; |
| 2149 | |
| 2150 | grow: |
| 2151 | shift = radix_tree_load_root(root, &child, &maxindex); |
| 2152 | if (!radix_tree_tagged(root, IDR_FREE)) |
| 2153 | start = max(start, maxindex + 1); |
| 2154 | if (start > max) |
| 2155 | return ERR_PTR(-ENOSPC); |
| 2156 | |
| 2157 | if (start > maxindex) { |
| 2158 | int error = radix_tree_extend(root, gfp, start, shift); |
| 2159 | if (error < 0) |
| 2160 | return ERR_PTR(error); |
| 2161 | shift = error; |
| 2162 | child = rcu_dereference_raw(root->rnode); |
| 2163 | } |
| 2164 | |
| 2165 | while (shift) { |
| 2166 | shift -= RADIX_TREE_MAP_SHIFT; |
| 2167 | if (child == NULL) { |
| 2168 | /* Have to add a child node. */ |
Matthew Wilcox | d58275b | 2017-01-16 17:10:21 -0500 | [diff] [blame] | 2169 | child = radix_tree_node_alloc(gfp, node, root, shift, |
| 2170 | offset, 0, 0); |
Matthew Wilcox | 0a835c4 | 2016-12-20 10:27:56 -0500 | [diff] [blame] | 2171 | if (!child) |
| 2172 | return ERR_PTR(-ENOMEM); |
| 2173 | all_tag_set(child, IDR_FREE); |
| 2174 | rcu_assign_pointer(*slot, node_to_entry(child)); |
| 2175 | if (node) |
| 2176 | node->count++; |
| 2177 | } else if (!radix_tree_is_internal_node(child)) |
| 2178 | break; |
| 2179 | |
| 2180 | node = entry_to_node(child); |
| 2181 | offset = radix_tree_descend(node, &child, start); |
| 2182 | if (!tag_get(node, IDR_FREE, offset)) { |
| 2183 | offset = radix_tree_find_next_bit(node, IDR_FREE, |
| 2184 | offset + 1); |
| 2185 | start = next_index(start, node, offset); |
| 2186 | if (start > max) |
| 2187 | return ERR_PTR(-ENOSPC); |
| 2188 | while (offset == RADIX_TREE_MAP_SIZE) { |
| 2189 | offset = node->offset + 1; |
| 2190 | node = node->parent; |
| 2191 | if (!node) |
| 2192 | goto grow; |
| 2193 | shift = node->shift; |
| 2194 | } |
| 2195 | child = rcu_dereference_raw(node->slots[offset]); |
| 2196 | } |
| 2197 | slot = &node->slots[offset]; |
| 2198 | } |
| 2199 | |
| 2200 | iter->index = start; |
| 2201 | if (node) |
| 2202 | iter->next_index = 1 + min(max, (start | node_maxindex(node))); |
| 2203 | else |
| 2204 | iter->next_index = 1; |
| 2205 | iter->node = node; |
| 2206 | __set_iter_shift(iter, shift); |
| 2207 | set_iter_tags(iter, node, offset, IDR_FREE); |
| 2208 | |
| 2209 | return slot; |
| 2210 | } |
| 2211 | |
| 2212 | /** |
| 2213 | * idr_destroy - release all internal memory from an IDR |
| 2214 | * @idr: idr handle |
| 2215 | * |
| 2216 | * After this function is called, the IDR is empty, and may be reused or |
| 2217 | * the data structure containing it may be freed. |
| 2218 | * |
| 2219 | * A typical clean-up sequence for objects stored in an idr tree will use |
| 2220 | * idr_for_each() to free all objects, if necessary, then idr_destroy() to |
| 2221 | * free the memory used to keep track of those objects. |
| 2222 | */ |
| 2223 | void idr_destroy(struct idr *idr) |
| 2224 | { |
| 2225 | struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode); |
| 2226 | if (radix_tree_is_internal_node(node)) |
| 2227 | radix_tree_free_nodes(node); |
| 2228 | idr->idr_rt.rnode = NULL; |
| 2229 | root_tag_set(&idr->idr_rt, IDR_FREE); |
| 2230 | } |
| 2231 | EXPORT_SYMBOL(idr_destroy); |
| 2232 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2233 | static void |
Johannes Weiner | 449dd69 | 2014-04-03 14:47:56 -0700 | [diff] [blame] | 2234 | radix_tree_node_ctor(void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | { |
Johannes Weiner | 449dd69 | 2014-04-03 14:47:56 -0700 | [diff] [blame] | 2236 | struct radix_tree_node *node = arg; |
| 2237 | |
| 2238 | memset(node, 0, sizeof(*node)); |
| 2239 | INIT_LIST_HEAD(&node->private_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2240 | } |
| 2241 | |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 2242 | static __init unsigned long __maxindex(unsigned int height) |
| 2243 | { |
| 2244 | unsigned int width = height * RADIX_TREE_MAP_SHIFT; |
| 2245 | int shift = RADIX_TREE_INDEX_BITS - width; |
| 2246 | |
| 2247 | if (shift < 0) |
| 2248 | return ~0UL; |
| 2249 | if (shift >= BITS_PER_LONG) |
| 2250 | return 0UL; |
| 2251 | return ~0UL >> shift; |
| 2252 | } |
| 2253 | |
| 2254 | static __init void radix_tree_init_maxnodes(void) |
| 2255 | { |
| 2256 | unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1]; |
| 2257 | unsigned int i, j; |
| 2258 | |
| 2259 | for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++) |
| 2260 | height_to_maxindex[i] = __maxindex(i); |
| 2261 | for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) { |
| 2262 | for (j = i; j > 0; j--) |
| 2263 | height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1; |
| 2264 | } |
| 2265 | } |
| 2266 | |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2267 | static int radix_tree_cpu_dead(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2268 | { |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 2269 | struct radix_tree_preload *rtp; |
| 2270 | struct radix_tree_node *node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2271 | |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 2272 | /* Free per-cpu pool of preloaded nodes */ |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2273 | rtp = &per_cpu(radix_tree_preloads, cpu); |
| 2274 | while (rtp->nr) { |
| 2275 | node = rtp->nodes; |
Matthew Wilcox | 1293d5c | 2017-01-16 16:41:29 -0500 | [diff] [blame] | 2276 | rtp->nodes = node->parent; |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2277 | kmem_cache_free(radix_tree_node_cachep, node); |
| 2278 | rtp->nr--; |
Matthew Wilcox | 2fcd900 | 2016-05-20 17:03:04 -0700 | [diff] [blame] | 2279 | } |
Matthew Wilcox | 7ad3d4d | 2016-12-16 11:55:56 -0500 | [diff] [blame] | 2280 | kfree(per_cpu(ida_bitmap, cpu)); |
| 2281 | per_cpu(ida_bitmap, cpu) = NULL; |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2282 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2283 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2284 | |
| 2285 | void __init radix_tree_init(void) |
| 2286 | { |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2287 | int ret; |
Michal Hocko | 7e78442 | 2017-05-03 14:53:09 -0700 | [diff] [blame] | 2288 | |
| 2289 | BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2290 | radix_tree_node_cachep = kmem_cache_create("radix_tree_node", |
| 2291 | sizeof(struct radix_tree_node), 0, |
Christoph Lameter | 488514d | 2008-04-28 02:12:05 -0700 | [diff] [blame] | 2292 | SLAB_PANIC | SLAB_RECLAIM_ACCOUNT, |
| 2293 | radix_tree_node_ctor); |
Kirill A. Shutemov | c78c66d | 2016-07-26 15:26:02 -0700 | [diff] [blame] | 2294 | radix_tree_init_maxnodes(); |
Sebastian Andrzej Siewior | d544abd | 2016-11-03 15:50:01 +0100 | [diff] [blame] | 2295 | ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead", |
| 2296 | NULL, radix_tree_cpu_dead); |
| 2297 | WARN_ON(ret < 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2298 | } |