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lib/radix-tree.c
34.6 KB
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/* * Copyright (C) 2001 Momchil Velikov * Portions Copyright (C) 2001 Christoph Hellwig |
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* Copyright (C) 2005 SGI, Christoph Lameter |
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* Copyright (C) 2006 Nick Piggin |
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* * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/errno.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/radix-tree.h> #include <linux/percpu.h> #include <linux/slab.h> #include <linux/notifier.h> #include <linux/cpu.h> |
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#include <linux/string.h> #include <linux/bitops.h> |
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#include <linux/rcupdate.h> |
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#ifdef __KERNEL__ |
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#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) |
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#else #define RADIX_TREE_MAP_SHIFT 3 /* For more stressful testing */ #endif |
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#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT) #define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1) #define RADIX_TREE_TAG_LONGS \ ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG) struct radix_tree_node { |
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unsigned int height; /* Height from the bottom */ |
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unsigned int count; |
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struct rcu_head rcu_head; |
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void *slots[RADIX_TREE_MAP_SIZE]; |
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unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; |
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}; struct radix_tree_path { |
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struct radix_tree_node *node; |
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int offset; }; #define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) |
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#define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \ RADIX_TREE_MAP_SHIFT)) |
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/* * The height_to_maxindex array needs to be one deeper than the maximum * path as height 0 holds only 1 entry. */ static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1] __read_mostly; |
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/* * Radix tree node cache. */ |
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static struct kmem_cache *radix_tree_node_cachep; |
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/* * Per-cpu pool of preloaded nodes */ struct radix_tree_preload { int nr; struct radix_tree_node *nodes[RADIX_TREE_MAX_PATH]; }; |
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static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; |
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static inline gfp_t root_gfp_mask(struct radix_tree_root *root) { return root->gfp_mask & __GFP_BITS_MASK; } |
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static inline void tag_set(struct radix_tree_node *node, unsigned int tag, int offset) { __set_bit(offset, node->tags[tag]); } static inline void tag_clear(struct radix_tree_node *node, unsigned int tag, int offset) { __clear_bit(offset, node->tags[tag]); } static inline int tag_get(struct radix_tree_node *node, unsigned int tag, int offset) { return test_bit(offset, node->tags[tag]); } static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag) { root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT)); } static inline void root_tag_clear(struct radix_tree_root *root, unsigned int tag) { root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT)); } static inline void root_tag_clear_all(struct radix_tree_root *root) { root->gfp_mask &= __GFP_BITS_MASK; } static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag) { return (__force unsigned)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); } /* * Returns 1 if any slot in the node has this tag set. * Otherwise returns 0. */ static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag) { int idx; for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { if (node->tags[tag][idx]) return 1; } return 0; } |
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/* * This assumes that the caller has performed appropriate preallocation, and * that the caller has pinned this thread of control to the current CPU. */ static struct radix_tree_node * radix_tree_node_alloc(struct radix_tree_root *root) { |
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struct radix_tree_node *ret = NULL; |
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gfp_t gfp_mask = root_gfp_mask(root); |
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|
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if (!(gfp_mask & __GFP_WAIT)) { |
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struct radix_tree_preload *rtp; |
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/* * Provided the caller has preloaded here, we will always * succeed in getting a node here (and never reach * kmem_cache_alloc) */ |
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rtp = &__get_cpu_var(radix_tree_preloads); if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; rtp->nodes[rtp->nr - 1] = NULL; rtp->nr--; } } |
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if (ret == NULL) |
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ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); |
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|
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BUG_ON(radix_tree_is_indirect_ptr(ret)); |
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return ret; } |
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static void radix_tree_node_rcu_free(struct rcu_head *head) { struct radix_tree_node *node = container_of(head, struct radix_tree_node, rcu_head); |
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/* * must only free zeroed nodes into the slab. radix_tree_shrink * can leave us with a non-NULL entry in the first slot, so clear * that here to make sure. */ tag_clear(node, 0, 0); tag_clear(node, 1, 0); node->slots[0] = NULL; node->count = 0; |
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kmem_cache_free(radix_tree_node_cachep, node); } |
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static inline void radix_tree_node_free(struct radix_tree_node *node) { |
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call_rcu(&node->rcu_head, radix_tree_node_rcu_free); |
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} /* * Load up this CPU's radix_tree_node buffer with sufficient objects to * ensure that the addition of a single element in the tree cannot fail. On * success, return zero, with preemption disabled. On error, return -ENOMEM * with preemption not disabled. |
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* * To make use of this facility, the radix tree must be initialised without * __GFP_WAIT being passed to INIT_RADIX_TREE(). |
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*/ |
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int radix_tree_preload(gfp_t gfp_mask) |
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{ struct radix_tree_preload *rtp; struct radix_tree_node *node; int ret = -ENOMEM; preempt_disable(); rtp = &__get_cpu_var(radix_tree_preloads); while (rtp->nr < ARRAY_SIZE(rtp->nodes)) { preempt_enable(); |
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node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); |
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if (node == NULL) goto out; preempt_disable(); rtp = &__get_cpu_var(radix_tree_preloads); if (rtp->nr < ARRAY_SIZE(rtp->nodes)) rtp->nodes[rtp->nr++] = node; else kmem_cache_free(radix_tree_node_cachep, node); } ret = 0; out: return ret; } |
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EXPORT_SYMBOL(radix_tree_preload); |
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|
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/* |
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* Return the maximum key which can be store into a * radix tree with height HEIGHT. */ static inline unsigned long radix_tree_maxindex(unsigned int height) { return height_to_maxindex[height]; } /* * Extend a radix tree so it can store key @index. */ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) { struct radix_tree_node *node; unsigned int height; |
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int tag; /* Figure out what the height should be. */ height = root->height + 1; while (index > radix_tree_maxindex(height)) height++; if (root->rnode == NULL) { root->height = height; goto out; } |
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do { |
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unsigned int newheight; |
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if (!(node = radix_tree_node_alloc(root))) return -ENOMEM; /* Increase the height. */ |
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node->slots[0] = radix_tree_indirect_to_ptr(root->rnode); |
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/* Propagate the aggregated tag info into the new root */ |
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for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { |
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if (root_tag_get(root, tag)) |
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tag_set(node, tag, 0); } |
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newheight = root->height+1; node->height = newheight; |
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node->count = 1; |
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node = radix_tree_ptr_to_indirect(node); |
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rcu_assign_pointer(root->rnode, node); root->height = newheight; |
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} while (height > root->height); out: return 0; } /** * radix_tree_insert - insert into a radix tree * @root: radix tree root * @index: index key * @item: item to insert * * Insert an item into the radix tree at position @index. */ int radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item) { |
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struct radix_tree_node *node = NULL, *slot; |
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unsigned int height, shift; int offset; int error; |
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BUG_ON(radix_tree_is_indirect_ptr(item)); |
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|
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/* Make sure the tree is high enough. */ |
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if (index > radix_tree_maxindex(root->height)) { |
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error = radix_tree_extend(root, index); if (error) return error; } |
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slot = radix_tree_indirect_to_ptr(root->rnode); |
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height = root->height; shift = (height-1) * RADIX_TREE_MAP_SHIFT; offset = 0; /* uninitialised var warning */ |
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while (height > 0) { |
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if (slot == NULL) { |
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/* Have to add a child node. */ |
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if (!(slot = radix_tree_node_alloc(root))) |
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return -ENOMEM; |
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slot->height = height; |
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if (node) { |
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rcu_assign_pointer(node->slots[offset], slot); |
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node->count++; |
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} else |
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rcu_assign_pointer(root->rnode, radix_tree_ptr_to_indirect(slot)); |
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} /* Go a level down */ offset = (index >> shift) & RADIX_TREE_MAP_MASK; |
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node = slot; slot = node->slots[offset]; |
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shift -= RADIX_TREE_MAP_SHIFT; height--; |
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} |
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|
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if (slot != NULL) |
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return -EEXIST; |
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if (node) { node->count++; |
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rcu_assign_pointer(node->slots[offset], item); |
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BUG_ON(tag_get(node, 0, offset)); BUG_ON(tag_get(node, 1, offset)); } else { |
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rcu_assign_pointer(root->rnode, item); |
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BUG_ON(root_tag_get(root, 0)); BUG_ON(root_tag_get(root, 1)); } |
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return 0; } EXPORT_SYMBOL(radix_tree_insert); |
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/* * is_slot == 1 : search for the slot. * is_slot == 0 : search for the node. |
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*/ |
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static void *radix_tree_lookup_element(struct radix_tree_root *root, unsigned long index, int is_slot) |
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{ unsigned int height, shift; |
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struct radix_tree_node *node, **slot; |
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|
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node = rcu_dereference_raw(root->rnode); |
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if (node == NULL) |
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return NULL; |
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if (!radix_tree_is_indirect_ptr(node)) { |
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if (index > 0) return NULL; |
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return is_slot ? (void *)&root->rnode : node; |
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} |
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node = radix_tree_indirect_to_ptr(node); |
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height = node->height; if (index > radix_tree_maxindex(height)) return NULL; |
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|
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shift = (height-1) * RADIX_TREE_MAP_SHIFT; |
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do { slot = (struct radix_tree_node **) (node->slots + ((index>>shift) & RADIX_TREE_MAP_MASK)); |
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node = rcu_dereference_raw(*slot); |
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if (node == NULL) |
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return NULL; |
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shift -= RADIX_TREE_MAP_SHIFT; height--; |
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} while (height > 0); |
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return is_slot ? (void *)slot:node; } /** * radix_tree_lookup_slot - lookup a slot in a radix tree * @root: radix tree root * @index: index key * * Returns: the slot corresponding to the position @index in the * radix tree @root. This is useful for update-if-exists operations. * * This function can be called under rcu_read_lock iff the slot is not * modified by radix_tree_replace_slot, otherwise it must be called * exclusive from other writers. Any dereference of the slot must be done * using radix_tree_deref_slot. */ void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) { return (void **)radix_tree_lookup_element(root, index, 1); |
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} |
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EXPORT_SYMBOL(radix_tree_lookup_slot); /** * radix_tree_lookup - perform lookup operation on a radix tree * @root: radix tree root * @index: index key * * Lookup the item at the position @index in the radix tree @root. |
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* * This function can be called under rcu_read_lock, however the caller * must manage lifetimes of leaf nodes (eg. RCU may also be used to free * them safely). No RCU barriers are required to access or modify the * returned item, however. |
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*/ void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) { |
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return radix_tree_lookup_element(root, index, 0); |
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} EXPORT_SYMBOL(radix_tree_lookup); /** * radix_tree_tag_set - set a tag on a radix tree node * @root: radix tree root * @index: index key * @tag: tag index * |
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* Set the search tag (which must be < RADIX_TREE_MAX_TAGS) * corresponding to @index in the radix tree. From |
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* the root all the way down to the leaf node. * * Returns the address of the tagged item. Setting a tag on a not-present * item is a bug. */ void *radix_tree_tag_set(struct radix_tree_root *root, |
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unsigned long index, unsigned int tag) |
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{ unsigned int height, shift; |
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struct radix_tree_node *slot; |
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height = root->height; |
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BUG_ON(index > radix_tree_maxindex(height)); |
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|
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slot = radix_tree_indirect_to_ptr(root->rnode); |
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shift = (height - 1) * RADIX_TREE_MAP_SHIFT; |
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while (height > 0) { int offset; offset = (index >> shift) & RADIX_TREE_MAP_MASK; |
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if (!tag_get(slot, tag, offset)) tag_set(slot, tag, offset); |
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slot = slot->slots[offset]; BUG_ON(slot == NULL); |
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shift -= RADIX_TREE_MAP_SHIFT; height--; } |
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/* set the root's tag bit */ if (slot && !root_tag_get(root, tag)) root_tag_set(root, tag); |
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return slot; |
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} EXPORT_SYMBOL(radix_tree_tag_set); /** * radix_tree_tag_clear - clear a tag on a radix tree node * @root: radix tree root * @index: index key * @tag: tag index * |
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* Clear the search tag (which must be < RADIX_TREE_MAX_TAGS) * corresponding to @index in the radix tree. If |
1da177e4c Linux-2.6.12-rc2 |
472 473 474 475 476 477 478 |
* this causes the leaf node to have no tags set then clear the tag in the * next-to-leaf node, etc. * * Returns the address of the tagged item on success, else NULL. ie: * has the same return value and semantics as radix_tree_lookup(). */ void *radix_tree_tag_clear(struct radix_tree_root *root, |
daff89f32 [PATCH] radix-tre... |
479 |
unsigned long index, unsigned int tag) |
1da177e4c Linux-2.6.12-rc2 |
480 |
{ |
26fb1589c fix the max path ... |
481 482 483 484 485 |
/* * The radix tree path needs to be one longer than the maximum path * since the "list" is null terminated. */ struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path; |
612d6c19d [PATCH] radix-tre... |
486 |
struct radix_tree_node *slot = NULL; |
1da177e4c Linux-2.6.12-rc2 |
487 |
unsigned int height, shift; |
1da177e4c Linux-2.6.12-rc2 |
488 489 490 491 492 493 494 |
height = root->height; if (index > radix_tree_maxindex(height)) goto out; shift = (height - 1) * RADIX_TREE_MAP_SHIFT; pathp->node = NULL; |
c0bc9875b radix-tree: use i... |
495 |
slot = radix_tree_indirect_to_ptr(root->rnode); |
1da177e4c Linux-2.6.12-rc2 |
496 497 498 |
while (height > 0) { int offset; |
201b6264f [PATCH] radix-tre... |
499 |
if (slot == NULL) |
1da177e4c Linux-2.6.12-rc2 |
500 501 502 503 |
goto out; offset = (index >> shift) & RADIX_TREE_MAP_MASK; pathp[1].offset = offset; |
201b6264f [PATCH] radix-tre... |
504 505 |
pathp[1].node = slot; slot = slot->slots[offset]; |
1da177e4c Linux-2.6.12-rc2 |
506 507 508 509 |
pathp++; shift -= RADIX_TREE_MAP_SHIFT; height--; } |
612d6c19d [PATCH] radix-tre... |
510 |
if (slot == NULL) |
1da177e4c Linux-2.6.12-rc2 |
511 |
goto out; |
612d6c19d [PATCH] radix-tre... |
512 |
while (pathp->node) { |
d5274261e [PATCH] radix tre... |
513 514 |
if (!tag_get(pathp->node, tag, pathp->offset)) goto out; |
201b6264f [PATCH] radix-tre... |
515 |
tag_clear(pathp->node, tag, pathp->offset); |
6e954b9e9 [PATCH] radix tre... |
516 517 |
if (any_tag_set(pathp->node, tag)) goto out; |
1da177e4c Linux-2.6.12-rc2 |
518 |
pathp--; |
612d6c19d [PATCH] radix-tre... |
519 520 521 522 523 |
} /* clear the root's tag bit */ if (root_tag_get(root, tag)) root_tag_clear(root, tag); |
1da177e4c Linux-2.6.12-rc2 |
524 |
out: |
612d6c19d [PATCH] radix-tre... |
525 |
return slot; |
1da177e4c Linux-2.6.12-rc2 |
526 527 |
} EXPORT_SYMBOL(radix_tree_tag_clear); |
1da177e4c Linux-2.6.12-rc2 |
528 |
/** |
32605a181 [PATCH] radix_tag... |
529 530 531 |
* radix_tree_tag_get - get a tag on a radix tree node * @root: radix tree root * @index: index key |
daff89f32 [PATCH] radix-tre... |
532 |
* @tag: tag index (< RADIX_TREE_MAX_TAGS) |
1da177e4c Linux-2.6.12-rc2 |
533 |
* |
32605a181 [PATCH] radix_tag... |
534 |
* Return values: |
1da177e4c Linux-2.6.12-rc2 |
535 |
* |
612d6c19d [PATCH] radix-tre... |
536 537 |
* 0: tag not present or not set * 1: tag set |
ce82653d6 radix_tree_tag_ge... |
538 539 540 541 |
* * Note that the return value of this function may not be relied on, even if * the RCU lock is held, unless tag modification and node deletion are excluded * from concurrency. |
1da177e4c Linux-2.6.12-rc2 |
542 543 |
*/ int radix_tree_tag_get(struct radix_tree_root *root, |
daff89f32 [PATCH] radix-tre... |
544 |
unsigned long index, unsigned int tag) |
1da177e4c Linux-2.6.12-rc2 |
545 546 |
{ unsigned int height, shift; |
7cf9c2c76 [PATCH] radix-tre... |
547 |
struct radix_tree_node *node; |
1da177e4c Linux-2.6.12-rc2 |
548 |
int saw_unset_tag = 0; |
612d6c19d [PATCH] radix-tre... |
549 550 551 |
/* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; |
2676a58c9 radix-tree: Disab... |
552 |
node = rcu_dereference_raw(root->rnode); |
7cf9c2c76 [PATCH] radix-tre... |
553 554 |
if (node == NULL) return 0; |
c0bc9875b radix-tree: use i... |
555 |
if (!radix_tree_is_indirect_ptr(node)) |
7cf9c2c76 [PATCH] radix-tre... |
556 |
return (index == 0); |
c0bc9875b radix-tree: use i... |
557 |
node = radix_tree_indirect_to_ptr(node); |
7cf9c2c76 [PATCH] radix-tre... |
558 559 560 561 |
height = node->height; if (index > radix_tree_maxindex(height)) return 0; |
612d6c19d [PATCH] radix-tre... |
562 |
|
1da177e4c Linux-2.6.12-rc2 |
563 |
shift = (height - 1) * RADIX_TREE_MAP_SHIFT; |
1da177e4c Linux-2.6.12-rc2 |
564 565 566 |
for ( ; ; ) { int offset; |
7cf9c2c76 [PATCH] radix-tre... |
567 |
if (node == NULL) |
1da177e4c Linux-2.6.12-rc2 |
568 569 570 571 572 573 574 575 |
return 0; offset = (index >> shift) & RADIX_TREE_MAP_MASK; /* * This is just a debug check. Later, we can bale as soon as * we see an unset tag. */ |
7cf9c2c76 [PATCH] radix-tre... |
576 |
if (!tag_get(node, tag, offset)) |
1da177e4c Linux-2.6.12-rc2 |
577 |
saw_unset_tag = 1; |
ce82653d6 radix_tree_tag_ge... |
578 579 |
if (height == 1) return !!tag_get(node, tag, offset); |
2676a58c9 radix-tree: Disab... |
580 |
node = rcu_dereference_raw(node->slots[offset]); |
1da177e4c Linux-2.6.12-rc2 |
581 582 583 584 585 |
shift -= RADIX_TREE_MAP_SHIFT; height--; } } EXPORT_SYMBOL(radix_tree_tag_get); |
1da177e4c Linux-2.6.12-rc2 |
586 |
|
6df8ba4f8 radixtree: introd... |
587 |
/** |
ebf8aa44b radix-tree: omple... |
588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 |
* radix_tree_range_tag_if_tagged - for each item in given range set given * tag if item has another tag set * @root: radix tree root * @first_indexp: pointer to a starting index of a range to scan * @last_index: last index of a range to scan * @nr_to_tag: maximum number items to tag * @iftag: tag index to test * @settag: tag index to set if tested tag is set * * This function scans range of radix tree from first_index to last_index * (inclusive). For each item in the range if iftag is set, the function sets * also settag. The function stops either after tagging nr_to_tag items or * after reaching last_index. * * The function returns number of leaves where the tag was set and sets * *first_indexp to the first unscanned index. */ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, unsigned long *first_indexp, unsigned long last_index, unsigned long nr_to_tag, unsigned int iftag, unsigned int settag) { unsigned int height = root->height, shift; unsigned long tagged = 0, index = *first_indexp; struct radix_tree_node *open_slots[height], *slot; last_index = min(last_index, radix_tree_maxindex(height)); if (index > last_index) return 0; if (!nr_to_tag) return 0; if (!root_tag_get(root, iftag)) { *first_indexp = last_index + 1; return 0; } if (height == 0) { *first_indexp = last_index + 1; root_tag_set(root, settag); return 1; } shift = (height - 1) * RADIX_TREE_MAP_SHIFT; slot = radix_tree_indirect_to_ptr(root->rnode); for (;;) { int offset; offset = (index >> shift) & RADIX_TREE_MAP_MASK; if (!slot->slots[offset]) goto next; if (!tag_get(slot, iftag, offset)) goto next; tag_set(slot, settag, offset); if (height == 1) { tagged++; goto next; } /* Go down one level */ height--; shift -= RADIX_TREE_MAP_SHIFT; open_slots[height] = slot; slot = slot->slots[offset]; continue; next: /* Go to next item at level determined by 'shift' */ index = ((index >> shift) + 1) << shift; if (index > last_index) break; if (tagged >= nr_to_tag) break; while (((index >> shift) & RADIX_TREE_MAP_MASK) == 0) { /* * We've fully scanned this node. Go up. Because * last_index is guaranteed to be in the tree, what * we do below cannot wander astray. */ slot = open_slots[height]; height++; shift += RADIX_TREE_MAP_SHIFT; } } /* * The iftag must have been set somewhere because otherwise * we would return immediated at the beginning of the function */ root_tag_set(root, settag); *first_indexp = index; return tagged; } EXPORT_SYMBOL(radix_tree_range_tag_if_tagged); /** |
6df8ba4f8 radixtree: introd... |
682 683 684 685 686 687 688 689 690 691 |
* radix_tree_next_hole - find the next hole (not-present entry) * @root: tree root * @index: index key * @max_scan: maximum range to search * * Search the set [index, min(index+max_scan-1, MAX_INDEX)] for the lowest * indexed hole. * * Returns: the index of the hole if found, otherwise returns an index * outside of the set specified (in which case 'return - index >= max_scan' |
8e6bdb7f8 trivial: radix-tr... |
692 |
* will be true). In rare cases of index wrap-around, 0 will be returned. |
6df8ba4f8 radixtree: introd... |
693 694 |
* * radix_tree_next_hole may be called under rcu_read_lock. However, like |
8e6bdb7f8 trivial: radix-tr... |
695 696 697 698 699 |
* radix_tree_gang_lookup, this will not atomically search a snapshot of * the tree at a single point in time. For example, if a hole is created * at index 5, then subsequently a hole is created at index 10, * radix_tree_next_hole covering both indexes may return 10 if called * under rcu_read_lock. |
6df8ba4f8 radixtree: introd... |
700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 |
*/ unsigned long radix_tree_next_hole(struct radix_tree_root *root, unsigned long index, unsigned long max_scan) { unsigned long i; for (i = 0; i < max_scan; i++) { if (!radix_tree_lookup(root, index)) break; index++; if (index == 0) break; } return index; } EXPORT_SYMBOL(radix_tree_next_hole); |
dc566127d radix-tree: add r... |
717 718 719 720 721 722 723 724 725 726 727 |
/** * radix_tree_prev_hole - find the prev hole (not-present entry) * @root: tree root * @index: index key * @max_scan: maximum range to search * * Search backwards in the range [max(index-max_scan+1, 0), index] * for the first hole. * * Returns: the index of the hole if found, otherwise returns an index * outside of the set specified (in which case 'index - return >= max_scan' |
edcd1d843 radix-tree: fix r... |
728 |
* will be true). In rare cases of wrap-around, ULONG_MAX will be returned. |
dc566127d radix-tree: add r... |
729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 |
* * radix_tree_next_hole may be called under rcu_read_lock. However, like * radix_tree_gang_lookup, this will not atomically search a snapshot of * the tree at a single point in time. For example, if a hole is created * at index 10, then subsequently a hole is created at index 5, * radix_tree_prev_hole covering both indexes may return 5 if called under * rcu_read_lock. */ unsigned long radix_tree_prev_hole(struct radix_tree_root *root, unsigned long index, unsigned long max_scan) { unsigned long i; for (i = 0; i < max_scan; i++) { if (!radix_tree_lookup(root, index)) break; index--; |
edcd1d843 radix-tree: fix r... |
746 |
if (index == ULONG_MAX) |
dc566127d radix-tree: add r... |
747 748 749 750 751 752 |
break; } return index; } EXPORT_SYMBOL(radix_tree_prev_hole); |
1da177e4c Linux-2.6.12-rc2 |
753 |
static unsigned int |
47feff2c8 radix-tree: add g... |
754 |
__lookup(struct radix_tree_node *slot, void ***results, unsigned long index, |
1da177e4c Linux-2.6.12-rc2 |
755 756 757 |
unsigned int max_items, unsigned long *next_index) { unsigned int nr_found = 0; |
201b6264f [PATCH] radix-tre... |
758 |
unsigned int shift, height; |
201b6264f [PATCH] radix-tre... |
759 |
unsigned long i; |
7cf9c2c76 [PATCH] radix-tre... |
760 761 |
height = slot->height; if (height == 0) |
201b6264f [PATCH] radix-tre... |
762 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
763 |
shift = (height-1) * RADIX_TREE_MAP_SHIFT; |
1da177e4c Linux-2.6.12-rc2 |
764 |
|
201b6264f [PATCH] radix-tre... |
765 |
for ( ; height > 1; height--) { |
7cf9c2c76 [PATCH] radix-tre... |
766 767 |
i = (index >> shift) & RADIX_TREE_MAP_MASK; for (;;) { |
1da177e4c Linux-2.6.12-rc2 |
768 769 770 771 772 773 |
if (slot->slots[i] != NULL) break; index &= ~((1UL << shift) - 1); index += 1UL << shift; if (index == 0) goto out; /* 32-bit wraparound */ |
7cf9c2c76 [PATCH] radix-tre... |
774 775 776 |
i++; if (i == RADIX_TREE_MAP_SIZE) goto out; |
1da177e4c Linux-2.6.12-rc2 |
777 |
} |
1da177e4c Linux-2.6.12-rc2 |
778 |
|
1da177e4c Linux-2.6.12-rc2 |
779 |
shift -= RADIX_TREE_MAP_SHIFT; |
2676a58c9 radix-tree: Disab... |
780 |
slot = rcu_dereference_raw(slot->slots[i]); |
7cf9c2c76 [PATCH] radix-tre... |
781 782 |
if (slot == NULL) goto out; |
1da177e4c Linux-2.6.12-rc2 |
783 |
} |
201b6264f [PATCH] radix-tre... |
784 785 786 787 |
/* Bottom level: grab some items */ for (i = index & RADIX_TREE_MAP_MASK; i < RADIX_TREE_MAP_SIZE; i++) { index++; |
47feff2c8 radix-tree: add g... |
788 789 |
if (slot->slots[i]) { results[nr_found++] = &(slot->slots[i]); |
201b6264f [PATCH] radix-tre... |
790 791 792 793 |
if (nr_found == max_items) goto out; } } |
1da177e4c Linux-2.6.12-rc2 |
794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 |
out: *next_index = index; return nr_found; } /** * radix_tree_gang_lookup - perform multiple lookup on a radix tree * @root: radix tree root * @results: where the results of the lookup are placed * @first_index: start the lookup from this key * @max_items: place up to this many items at *results * * Performs an index-ascending scan of the tree for present items. Places * them at *@results and returns the number of items which were placed at * *@results. * * The implementation is naive. |
7cf9c2c76 [PATCH] radix-tre... |
811 812 813 814 815 816 |
* * Like radix_tree_lookup, radix_tree_gang_lookup may be called under * rcu_read_lock. In this case, rather than the returned results being * an atomic snapshot of the tree at a single point in time, the semantics * of an RCU protected gang lookup are as though multiple radix_tree_lookups * have been issued in individual locks, and results stored in 'results'. |
1da177e4c Linux-2.6.12-rc2 |
817 818 819 820 821 |
*/ unsigned int radix_tree_gang_lookup(struct radix_tree_root *root, void **results, unsigned long first_index, unsigned int max_items) { |
7cf9c2c76 [PATCH] radix-tre... |
822 823 |
unsigned long max_index; struct radix_tree_node *node; |
1da177e4c Linux-2.6.12-rc2 |
824 |
unsigned long cur_index = first_index; |
7cf9c2c76 [PATCH] radix-tre... |
825 |
unsigned int ret; |
2676a58c9 radix-tree: Disab... |
826 |
node = rcu_dereference_raw(root->rnode); |
7cf9c2c76 [PATCH] radix-tre... |
827 828 |
if (!node) return 0; |
1da177e4c Linux-2.6.12-rc2 |
829 |
|
c0bc9875b radix-tree: use i... |
830 |
if (!radix_tree_is_indirect_ptr(node)) { |
7cf9c2c76 [PATCH] radix-tre... |
831 832 |
if (first_index > 0) return 0; |
c0bc9875b radix-tree: use i... |
833 |
results[0] = node; |
7cf9c2c76 [PATCH] radix-tre... |
834 835 |
return 1; } |
c0bc9875b radix-tree: use i... |
836 |
node = radix_tree_indirect_to_ptr(node); |
7cf9c2c76 [PATCH] radix-tre... |
837 838 839 840 |
max_index = radix_tree_maxindex(node->height); ret = 0; |
1da177e4c Linux-2.6.12-rc2 |
841 |
while (ret < max_items) { |
47feff2c8 radix-tree: add g... |
842 |
unsigned int nr_found, slots_found, i; |
1da177e4c Linux-2.6.12-rc2 |
843 844 845 846 |
unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; |
47feff2c8 radix-tree: add g... |
847 |
slots_found = __lookup(node, (void ***)results + ret, cur_index, |
1da177e4c Linux-2.6.12-rc2 |
848 |
max_items - ret, &next_index); |
47feff2c8 radix-tree: add g... |
849 850 851 852 853 854 |
nr_found = 0; for (i = 0; i < slots_found; i++) { struct radix_tree_node *slot; slot = *(((void ***)results)[ret + i]); if (!slot) continue; |
2676a58c9 radix-tree: Disab... |
855 |
results[ret + nr_found] = rcu_dereference_raw(slot); |
47feff2c8 radix-tree: add g... |
856 857 |
nr_found++; } |
1da177e4c Linux-2.6.12-rc2 |
858 859 860 861 862 |
ret += nr_found; if (next_index == 0) break; cur_index = next_index; } |
7cf9c2c76 [PATCH] radix-tre... |
863 |
|
1da177e4c Linux-2.6.12-rc2 |
864 865 866 |
return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup); |
47feff2c8 radix-tree: add g... |
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 |
/** * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree * @root: radix tree root * @results: where the results of the lookup are placed * @first_index: start the lookup from this key * @max_items: place up to this many items at *results * * Performs an index-ascending scan of the tree for present items. Places * their slots at *@results and returns the number of items which were * placed at *@results. * * The implementation is naive. * * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must * be dereferenced with radix_tree_deref_slot, and if using only RCU * protection, radix_tree_deref_slot may fail requiring a retry. */ unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results, unsigned long first_index, unsigned int max_items) { unsigned long max_index; struct radix_tree_node *node; unsigned long cur_index = first_index; unsigned int ret; |
2676a58c9 radix-tree: Disab... |
892 |
node = rcu_dereference_raw(root->rnode); |
47feff2c8 radix-tree: add g... |
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 |
if (!node) return 0; if (!radix_tree_is_indirect_ptr(node)) { if (first_index > 0) return 0; results[0] = (void **)&root->rnode; return 1; } node = radix_tree_indirect_to_ptr(node); max_index = radix_tree_maxindex(node->height); ret = 0; while (ret < max_items) { unsigned int slots_found; unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; slots_found = __lookup(node, results + ret, cur_index, max_items - ret, &next_index); ret += slots_found; if (next_index == 0) break; cur_index = next_index; } return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup_slot); |
1da177e4c Linux-2.6.12-rc2 |
924 925 926 927 928 |
/* * FIXME: the two tag_get()s here should use find_next_bit() instead of * open-coding the search. */ static unsigned int |
47feff2c8 radix-tree: add g... |
929 |
__lookup_tag(struct radix_tree_node *slot, void ***results, unsigned long index, |
daff89f32 [PATCH] radix-tre... |
930 |
unsigned int max_items, unsigned long *next_index, unsigned int tag) |
1da177e4c Linux-2.6.12-rc2 |
931 932 |
{ unsigned int nr_found = 0; |
7cf9c2c76 [PATCH] radix-tre... |
933 |
unsigned int shift, height; |
1da177e4c Linux-2.6.12-rc2 |
934 |
|
7cf9c2c76 [PATCH] radix-tre... |
935 936 |
height = slot->height; if (height == 0) |
612d6c19d [PATCH] radix-tre... |
937 |
goto out; |
7cf9c2c76 [PATCH] radix-tre... |
938 |
shift = (height-1) * RADIX_TREE_MAP_SHIFT; |
1da177e4c Linux-2.6.12-rc2 |
939 |
|
7cf9c2c76 [PATCH] radix-tre... |
940 941 |
while (height > 0) { unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK ; |
1da177e4c Linux-2.6.12-rc2 |
942 |
|
7cf9c2c76 [PATCH] radix-tre... |
943 944 |
for (;;) { if (tag_get(slot, tag, i)) |
1da177e4c Linux-2.6.12-rc2 |
945 |
break; |
1da177e4c Linux-2.6.12-rc2 |
946 947 948 949 |
index &= ~((1UL << shift) - 1); index += 1UL << shift; if (index == 0) goto out; /* 32-bit wraparound */ |
7cf9c2c76 [PATCH] radix-tre... |
950 951 952 |
i++; if (i == RADIX_TREE_MAP_SIZE) goto out; |
1da177e4c Linux-2.6.12-rc2 |
953 |
} |
1da177e4c Linux-2.6.12-rc2 |
954 955 956 957 958 959 |
height--; if (height == 0) { /* Bottom level: grab some items */ unsigned long j = index & RADIX_TREE_MAP_MASK; for ( ; j < RADIX_TREE_MAP_SIZE; j++) { index++; |
7cf9c2c76 [PATCH] radix-tre... |
960 961 |
if (!tag_get(slot, tag, j)) continue; |
7cf9c2c76 [PATCH] radix-tre... |
962 963 964 965 966 967 968 969 970 971 |
/* * Even though the tag was found set, we need to * recheck that we have a non-NULL node, because * if this lookup is lockless, it may have been * subsequently deleted. * * Similar care must be taken in any place that * lookup ->slots[x] without a lock (ie. can't * rely on its value remaining the same). */ |
47feff2c8 radix-tree: add g... |
972 973 |
if (slot->slots[j]) { results[nr_found++] = &(slot->slots[j]); |
1da177e4c Linux-2.6.12-rc2 |
974 975 976 977 978 979 |
if (nr_found == max_items) goto out; } } } shift -= RADIX_TREE_MAP_SHIFT; |
2676a58c9 radix-tree: Disab... |
980 |
slot = rcu_dereference_raw(slot->slots[i]); |
7cf9c2c76 [PATCH] radix-tre... |
981 982 983 |
if (slot == NULL) break; } |
1da177e4c Linux-2.6.12-rc2 |
984 985 986 987 988 989 990 991 992 993 994 995 |
out: *next_index = index; return nr_found; } /** * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree * based on a tag * @root: radix tree root * @results: where the results of the lookup are placed * @first_index: start the lookup from this key * @max_items: place up to this many items at *results |
daff89f32 [PATCH] radix-tre... |
996 |
* @tag: the tag index (< RADIX_TREE_MAX_TAGS) |
1da177e4c Linux-2.6.12-rc2 |
997 998 999 1000 1001 1002 1003 |
* * Performs an index-ascending scan of the tree for present items which * have the tag indexed by @tag set. Places the items at *@results and * returns the number of items which were placed at *@results. */ unsigned int radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, |
daff89f32 [PATCH] radix-tre... |
1004 1005 |
unsigned long first_index, unsigned int max_items, unsigned int tag) |
1da177e4c Linux-2.6.12-rc2 |
1006 |
{ |
7cf9c2c76 [PATCH] radix-tre... |
1007 1008 |
struct radix_tree_node *node; unsigned long max_index; |
1da177e4c Linux-2.6.12-rc2 |
1009 |
unsigned long cur_index = first_index; |
7cf9c2c76 [PATCH] radix-tre... |
1010 |
unsigned int ret; |
1da177e4c Linux-2.6.12-rc2 |
1011 |
|
612d6c19d [PATCH] radix-tre... |
1012 1013 1014 |
/* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; |
2676a58c9 radix-tree: Disab... |
1015 |
node = rcu_dereference_raw(root->rnode); |
7cf9c2c76 [PATCH] radix-tre... |
1016 1017 |
if (!node) return 0; |
c0bc9875b radix-tree: use i... |
1018 |
if (!radix_tree_is_indirect_ptr(node)) { |
7cf9c2c76 [PATCH] radix-tre... |
1019 1020 |
if (first_index > 0) return 0; |
c0bc9875b radix-tree: use i... |
1021 |
results[0] = node; |
7cf9c2c76 [PATCH] radix-tre... |
1022 1023 |
return 1; } |
c0bc9875b radix-tree: use i... |
1024 |
node = radix_tree_indirect_to_ptr(node); |
7cf9c2c76 [PATCH] radix-tre... |
1025 1026 1027 1028 |
max_index = radix_tree_maxindex(node->height); ret = 0; |
1da177e4c Linux-2.6.12-rc2 |
1029 |
while (ret < max_items) { |
47feff2c8 radix-tree: add g... |
1030 |
unsigned int nr_found, slots_found, i; |
1da177e4c Linux-2.6.12-rc2 |
1031 1032 1033 1034 |
unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; |
47feff2c8 radix-tree: add g... |
1035 1036 1037 1038 1039 1040 1041 1042 |
slots_found = __lookup_tag(node, (void ***)results + ret, cur_index, max_items - ret, &next_index, tag); nr_found = 0; for (i = 0; i < slots_found; i++) { struct radix_tree_node *slot; slot = *(((void ***)results)[ret + i]); if (!slot) continue; |
2676a58c9 radix-tree: Disab... |
1043 |
results[ret + nr_found] = rcu_dereference_raw(slot); |
47feff2c8 radix-tree: add g... |
1044 1045 |
nr_found++; } |
1da177e4c Linux-2.6.12-rc2 |
1046 1047 1048 1049 1050 |
ret += nr_found; if (next_index == 0) break; cur_index = next_index; } |
7cf9c2c76 [PATCH] radix-tre... |
1051 |
|
1da177e4c Linux-2.6.12-rc2 |
1052 1053 1054 1055 1056 |
return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup_tag); /** |
47feff2c8 radix-tree: add g... |
1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 |
* radix_tree_gang_lookup_tag_slot - perform multiple slot lookup on a * radix tree based on a tag * @root: radix tree root * @results: where the results of the lookup are placed * @first_index: start the lookup from this key * @max_items: place up to this many items at *results * @tag: the tag index (< RADIX_TREE_MAX_TAGS) * * Performs an index-ascending scan of the tree for present items which * have the tag indexed by @tag set. Places the slots at *@results and * returns the number of slots which were placed at *@results. */ unsigned int radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, unsigned long first_index, unsigned int max_items, unsigned int tag) { struct radix_tree_node *node; unsigned long max_index; unsigned long cur_index = first_index; unsigned int ret; /* check the root's tag bit */ if (!root_tag_get(root, tag)) return 0; |
2676a58c9 radix-tree: Disab... |
1082 |
node = rcu_dereference_raw(root->rnode); |
47feff2c8 radix-tree: add g... |
1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 |
if (!node) return 0; if (!radix_tree_is_indirect_ptr(node)) { if (first_index > 0) return 0; results[0] = (void **)&root->rnode; return 1; } node = radix_tree_indirect_to_ptr(node); max_index = radix_tree_maxindex(node->height); ret = 0; while (ret < max_items) { unsigned int slots_found; unsigned long next_index; /* Index of next search */ if (cur_index > max_index) break; slots_found = __lookup_tag(node, results + ret, cur_index, max_items - ret, &next_index, tag); ret += slots_found; if (next_index == 0) break; cur_index = next_index; } return ret; } EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot); /** |
a5f51c966 [PATCH] radix-tre... |
1117 1118 1119 1120 1121 1122 |
* radix_tree_shrink - shrink height of a radix tree to minimal * @root radix tree root */ static inline void radix_tree_shrink(struct radix_tree_root *root) { /* try to shrink tree height */ |
c0bc9875b radix-tree: use i... |
1123 |
while (root->height > 0) { |
a5f51c966 [PATCH] radix-tre... |
1124 |
struct radix_tree_node *to_free = root->rnode; |
7cf9c2c76 [PATCH] radix-tre... |
1125 |
void *newptr; |
a5f51c966 [PATCH] radix-tre... |
1126 |
|
c0bc9875b radix-tree: use i... |
1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 |
BUG_ON(!radix_tree_is_indirect_ptr(to_free)); to_free = radix_tree_indirect_to_ptr(to_free); /* * The candidate node has more than one child, or its child * is not at the leftmost slot, we cannot shrink. */ if (to_free->count != 1) break; if (!to_free->slots[0]) break; |
7cf9c2c76 [PATCH] radix-tre... |
1138 1139 1140 1141 1142 1143 1144 1145 |
/* * We don't need rcu_assign_pointer(), since we are simply * moving the node from one part of the tree to another. If * it was safe to dereference the old pointer to it * (to_free->slots[0]), it will be safe to dereference the new * one (root->rnode). */ newptr = to_free->slots[0]; |
c0bc9875b radix-tree: use i... |
1146 1147 |
if (root->height > 1) newptr = radix_tree_ptr_to_indirect(newptr); |
7cf9c2c76 [PATCH] radix-tre... |
1148 |
root->rnode = newptr; |
a5f51c966 [PATCH] radix-tre... |
1149 |
root->height--; |
a5f51c966 [PATCH] radix-tre... |
1150 1151 1152 1153 1154 |
radix_tree_node_free(to_free); } } /** |
1da177e4c Linux-2.6.12-rc2 |
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 |
* radix_tree_delete - delete an item from a radix tree * @root: radix tree root * @index: index key * * Remove the item at @index from the radix tree rooted at @root. * * Returns the address of the deleted item, or NULL if it was not present. */ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) { |
26fb1589c fix the max path ... |
1165 1166 1167 1168 1169 |
/* * The radix tree path needs to be one longer than the maximum path * since the "list" is null terminated. */ struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path; |
612d6c19d [PATCH] radix-tre... |
1170 |
struct radix_tree_node *slot = NULL; |
7cf9c2c76 [PATCH] radix-tre... |
1171 |
struct radix_tree_node *to_free; |
1da177e4c Linux-2.6.12-rc2 |
1172 |
unsigned int height, shift; |
d5274261e [PATCH] radix tre... |
1173 1174 |
int tag; int offset; |
1da177e4c Linux-2.6.12-rc2 |
1175 1176 1177 1178 |
height = root->height; if (index > radix_tree_maxindex(height)) goto out; |
612d6c19d [PATCH] radix-tre... |
1179 |
slot = root->rnode; |
c0bc9875b radix-tree: use i... |
1180 |
if (height == 0) { |
612d6c19d [PATCH] radix-tre... |
1181 1182 1183 1184 |
root_tag_clear_all(root); root->rnode = NULL; goto out; } |
c0bc9875b radix-tree: use i... |
1185 |
slot = radix_tree_indirect_to_ptr(slot); |
612d6c19d [PATCH] radix-tre... |
1186 |
|
1da177e4c Linux-2.6.12-rc2 |
1187 1188 |
shift = (height - 1) * RADIX_TREE_MAP_SHIFT; pathp->node = NULL; |
1da177e4c Linux-2.6.12-rc2 |
1189 |
|
612d6c19d [PATCH] radix-tre... |
1190 |
do { |
201b6264f [PATCH] radix-tre... |
1191 |
if (slot == NULL) |
1da177e4c Linux-2.6.12-rc2 |
1192 |
goto out; |
d5274261e [PATCH] radix tre... |
1193 |
pathp++; |
1da177e4c Linux-2.6.12-rc2 |
1194 |
offset = (index >> shift) & RADIX_TREE_MAP_MASK; |
d5274261e [PATCH] radix tre... |
1195 1196 |
pathp->offset = offset; pathp->node = slot; |
201b6264f [PATCH] radix-tre... |
1197 |
slot = slot->slots[offset]; |
1da177e4c Linux-2.6.12-rc2 |
1198 |
shift -= RADIX_TREE_MAP_SHIFT; |
612d6c19d [PATCH] radix-tre... |
1199 1200 |
height--; } while (height > 0); |
1da177e4c Linux-2.6.12-rc2 |
1201 |
|
612d6c19d [PATCH] radix-tre... |
1202 |
if (slot == NULL) |
1da177e4c Linux-2.6.12-rc2 |
1203 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
1204 1205 1206 |
/* * Clear all tags associated with the just-deleted item */ |
daff89f32 [PATCH] radix-tre... |
1207 |
for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { |
612d6c19d [PATCH] radix-tre... |
1208 1209 |
if (tag_get(pathp->node, tag, pathp->offset)) radix_tree_tag_clear(root, index, tag); |
d5274261e [PATCH] radix tre... |
1210 |
} |
1da177e4c Linux-2.6.12-rc2 |
1211 |
|
7cf9c2c76 [PATCH] radix-tre... |
1212 |
to_free = NULL; |
201b6264f [PATCH] radix-tre... |
1213 |
/* Now free the nodes we do not need anymore */ |
612d6c19d [PATCH] radix-tre... |
1214 |
while (pathp->node) { |
201b6264f [PATCH] radix-tre... |
1215 |
pathp->node->slots[pathp->offset] = NULL; |
a5f51c966 [PATCH] radix-tre... |
1216 |
pathp->node->count--; |
7cf9c2c76 [PATCH] radix-tre... |
1217 1218 1219 1220 1221 1222 |
/* * Queue the node for deferred freeing after the * last reference to it disappears (set NULL, above). */ if (to_free) radix_tree_node_free(to_free); |
a5f51c966 [PATCH] radix-tre... |
1223 1224 |
if (pathp->node->count) { |
c0bc9875b radix-tree: use i... |
1225 1226 |
if (pathp->node == radix_tree_indirect_to_ptr(root->rnode)) |
a5f51c966 [PATCH] radix-tre... |
1227 |
radix_tree_shrink(root); |
201b6264f [PATCH] radix-tre... |
1228 |
goto out; |
a5f51c966 [PATCH] radix-tre... |
1229 |
} |
201b6264f [PATCH] radix-tre... |
1230 1231 |
/* Node with zero slots in use so free it */ |
7cf9c2c76 [PATCH] radix-tre... |
1232 |
to_free = pathp->node; |
612d6c19d [PATCH] radix-tre... |
1233 |
pathp--; |
7cf9c2c76 [PATCH] radix-tre... |
1234 |
|
1da177e4c Linux-2.6.12-rc2 |
1235 |
} |
612d6c19d [PATCH] radix-tre... |
1236 |
root_tag_clear_all(root); |
201b6264f [PATCH] radix-tre... |
1237 |
root->height = 0; |
612d6c19d [PATCH] radix-tre... |
1238 |
root->rnode = NULL; |
7cf9c2c76 [PATCH] radix-tre... |
1239 1240 |
if (to_free) radix_tree_node_free(to_free); |
612d6c19d [PATCH] radix-tre... |
1241 |
|
1da177e4c Linux-2.6.12-rc2 |
1242 |
out: |
612d6c19d [PATCH] radix-tre... |
1243 |
return slot; |
1da177e4c Linux-2.6.12-rc2 |
1244 1245 1246 1247 1248 1249 1250 1251 |
} EXPORT_SYMBOL(radix_tree_delete); /** * radix_tree_tagged - test whether any items in the tree are tagged * @root: radix tree root * @tag: tag to test */ |
daff89f32 [PATCH] radix-tre... |
1252 |
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) |
1da177e4c Linux-2.6.12-rc2 |
1253 |
{ |
612d6c19d [PATCH] radix-tre... |
1254 |
return root_tag_get(root, tag); |
1da177e4c Linux-2.6.12-rc2 |
1255 1256 1257 1258 |
} EXPORT_SYMBOL(radix_tree_tagged); static void |
51cc50685 SL*B: drop kmem c... |
1259 |
radix_tree_node_ctor(void *node) |
1da177e4c Linux-2.6.12-rc2 |
1260 1261 1262 1263 1264 1265 |
{ memset(node, 0, sizeof(struct radix_tree_node)); } static __init unsigned long __maxindex(unsigned int height) { |
430d275a3 avoid negative (a... |
1266 1267 1268 1269 1270 1271 1272 1273 |
unsigned int width = height * RADIX_TREE_MAP_SHIFT; int shift = RADIX_TREE_INDEX_BITS - width; if (shift < 0) return ~0UL; if (shift >= BITS_PER_LONG) return 0UL; return ~0UL >> shift; |
1da177e4c Linux-2.6.12-rc2 |
1274 1275 1276 1277 1278 1279 1280 1281 1282 |
} static __init void radix_tree_init_maxindex(void) { unsigned int i; for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++) height_to_maxindex[i] = __maxindex(i); } |
1da177e4c Linux-2.6.12-rc2 |
1283 1284 1285 1286 1287 1288 1289 1290 |
static int radix_tree_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { int cpu = (long)hcpu; struct radix_tree_preload *rtp; /* Free per-cpu pool of perloaded nodes */ |
8bb784428 Add suspend-relat... |
1291 |
if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { |
1da177e4c Linux-2.6.12-rc2 |
1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 |
rtp = &per_cpu(radix_tree_preloads, cpu); while (rtp->nr) { kmem_cache_free(radix_tree_node_cachep, rtp->nodes[rtp->nr-1]); rtp->nodes[rtp->nr-1] = NULL; rtp->nr--; } } return NOTIFY_OK; } |
1da177e4c Linux-2.6.12-rc2 |
1302 1303 1304 1305 1306 |
void __init radix_tree_init(void) { radix_tree_node_cachep = kmem_cache_create("radix_tree_node", sizeof(struct radix_tree_node), 0, |
488514d17 Remove set_migrat... |
1307 1308 |
SLAB_PANIC | SLAB_RECLAIM_ACCOUNT, radix_tree_node_ctor); |
1da177e4c Linux-2.6.12-rc2 |
1309 1310 1311 |
radix_tree_init_maxindex(); hotcpu_notifier(radix_tree_callback, 0); } |