Release 4.10 lib/radix-tree.c

Directory: lib
/*
 * Copyright (C) 2001 Momchil Velikov
 * Portions Copyright (C) 2001 Christoph Hellwig
 * Copyright (C) 2005 SGI, Christoph Lameter
 * Copyright (C) 2006 Nick Piggin
 * Copyright (C) 2012 Konstantin Khlebnikov
 * Copyright (C) 2016 Intel, Matthew Wilcox
 * Copyright (C) 2016 Intel, Ross Zwisler
 *
 * 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/cpu.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/radix-tree.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/kmemleak.h>
#include <linux/cpu.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/rcupdate.h>
#include <linux/preempt.h>		/* in_interrupt() */


/* Number of nodes in fully populated tree of given height */

static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly;

/*
 * Radix tree node cache.
 */

static struct kmem_cache *radix_tree_node_cachep;

/*
 * The radix tree is variable-height, so an insert operation not only has
 * to build the branch to its corresponding item, it also has to build the
 * branch to existing items if the size has to be increased (by
 * radix_tree_extend).
 *
 * The worst case is a zero height tree with just a single item at index 0,
 * and then inserting an item at index ULONG_MAX. This requires 2 new branches
 * of RADIX_TREE_MAX_PATH size to be created, with only the root node shared.
 * Hence:
 */

#define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1)

/*
 * Per-cpu pool of preloaded nodes
 */

struct radix_tree_preload {
	
unsigned nr;
	/* nodes->private_data points to next preallocated node */
	
struct radix_tree_node *nodes;
};
static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };



static inline struct radix_tree_node *entry_to_node(void *ptr)
{
	return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
}

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matthew wilcox matthew wilcox 29 100.00% 1 100.00%
Total 29 100.00% 1 100.00%



static inline void *node_to_entry(void *ptr)
{
	return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE);
}

Contributors
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nick piggin nick piggin 25 92.59% 1 33.33%
matthew wilcox matthew wilcox 2 7.41% 2 66.67%
Total 27 100.00% 3 100.00%


#define RADIX_TREE_RETRY	node_to_entry(NULL)

#ifdef CONFIG_RADIX_TREE_MULTIORDER
/* Sibling slots point directly to another slot in the same node */


static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node)
{
	void **ptr = node;
	return (parent->slots <= ptr) &&
			(ptr < parent->slots + RADIX_TREE_MAP_SIZE);
}
Contributors
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matthew wilcox matthew wilcox 42 100.00% 1 100.00%
Total 42 100.00% 1 100.00%

#else


static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node)
{
	return false;
}
Contributors
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matthew wilcox matthew wilcox 19 100.00% 1 100.00%
Total 19 100.00% 1 100.00%

#endif



static inline unsigned long get_slot_offset(struct radix_tree_node *parent,
						 void **slot)
{
	return slot - parent->slots;
}

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matthew wilcox matthew wilcox 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



static unsigned int radix_tree_descend(struct radix_tree_node *parent,
			struct radix_tree_node **nodep, unsigned long index)
{
	unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK;
	void **entry = rcu_dereference_raw(parent->slots[offset]);

#ifdef CONFIG_RADIX_TREE_MULTIORDER
	if (radix_tree_is_internal_node(entry)) {
		if (is_sibling_entry(parent, entry)) {
			void **sibentry = (void **) entry_to_node(entry);
			offset = get_slot_offset(parent, sibentry);
			entry = rcu_dereference_raw(*sibentry);
		}
	}
#endif

	*nodep = (void *)entry;
	return offset;
}

Contributors
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matthew wilcox matthew wilcox 94 78.33% 3 75.00%
linus torvalds linus torvalds 26 21.67% 1 25.00%
Total 120 100.00% 4 100.00%



static inline gfp_t root_gfp_mask(struct radix_tree_root *root)
{
	return root->gfp_mask & __GFP_BITS_MASK;
}

Contributors
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nick piggin nick piggin 19 100.00% 1 100.00%
Total 19 100.00% 1 100.00%



static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
		int offset)
{
	__set_bit(offset, node->tags[tag]);
}

Contributors
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nick piggin nick piggin 20 64.52% 1 25.00%
andrew morton andrew morton 11 35.48% 3 75.00%
Total 31 100.00% 4 100.00%



static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
		int offset)
{
	__clear_bit(offset, node->tags[tag]);
}

Contributors
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nick piggin nick piggin 26 83.87% 1 50.00%
andrew morton andrew morton 5 16.13% 1 50.00%
Total 31 100.00% 2 100.00%



static inline int tag_get(struct radix_tree_node *node, unsigned int tag,
		int offset)
{
	return test_bit(offset, node->tags[tag]);
}

Contributors
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nick piggin nick piggin 30 93.75% 3 75.00%
andrew morton andrew morton 2 6.25% 1 25.00%
Total 32 100.00% 4 100.00%



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));
}

Contributors
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nick piggin nick piggin 34 100.00% 2 100.00%
Total 34 100.00% 2 100.00%



static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag)
{
	root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT));
}

Contributors
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nick piggin nick piggin 24 70.59% 2 40.00%
andrew morton andrew morton 10 29.41% 3 60.00%
Total 34 100.00% 5 100.00%



static inline void root_tag_clear_all(struct radix_tree_root *root)
{
	root->gfp_mask &= __GFP_BITS_MASK;
}

Contributors
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nick piggin nick piggin 15 83.33% 1 50.00%
andrew morton andrew morton 3 16.67% 1 50.00%
Total 18 100.00% 2 100.00%



static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag)
{
	return (__force int)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT));
}

Contributors
Person Tokens Prop Commits CommitProp
nick piggin nick piggin 32 91.43% 1 33.33%
andrew morton andrew morton 2 5.71% 1 33.33%
matthew wilcox matthew wilcox 1 2.86% 1 33.33%
Total 35 100.00% 3 100.00%



static inline unsigned root_tags_get(struct radix_tree_root *root)
{
	return (__force unsigned)root->gfp_mask >> __GFP_BITS_SHIFT;
}

Contributors
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matthew wilcox matthew wilcox 23 100.00% 1 100.00%
Total 23 100.00% 1 100.00%

/*
 * 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)
{
	unsigned idx;
	for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
		if (node->tags[tag][idx])
			return 1;
	}
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
nick piggin nick piggin 41 78.85% 1 33.33%
andrew morton andrew morton 10 19.23% 1 33.33%
matthew wilcox matthew wilcox 1 1.92% 1 33.33%
Total 52 100.00% 3 100.00%

/**
 * radix_tree_find_next_bit - find the next set bit in a memory region
 *
 * @addr: The address to base the search on
 * @size: The bitmap size in bits
 * @offset: The bitnumber to start searching at
 *
 * Unrollable variant of find_next_bit() for constant size arrays.
 * Tail bits starting from size to roundup(size, BITS_PER_LONG) must be zero.
 * Returns next bit offset, or size if nothing found.
 */

static __always_inline unsigned long

radix_tree_find_next_bit(struct radix_tree_node *node, unsigned int tag,
			 unsigned long offset)
{
	const unsigned long *addr = node->tags[tag];

	if (offset < RADIX_TREE_MAP_SIZE) {
		unsigned long tmp;

		addr += offset / BITS_PER_LONG;
		tmp = *addr >> (offset % BITS_PER_LONG);
		if (tmp)
			return __ffs(tmp) + offset;
		offset = (offset + BITS_PER_LONG) & ~(BITS_PER_LONG - 1);
		while (offset < RADIX_TREE_MAP_SIZE) {
			tmp = *++addr;
			if (tmp)
				return __ffs(tmp) + offset;
			offset += BITS_PER_LONG;
		}
	}
	return RADIX_TREE_MAP_SIZE;
}

Contributors
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konstantin khlebnikov konstantin khlebnikov 103 83.74% 1 50.00%
matthew wilcox matthew wilcox 20 16.26% 1 50.00%
Total 123 100.00% 2 100.00%



static unsigned int iter_offset(const struct radix_tree_iter *iter)
{
	return (iter->index >> iter_shift(iter)) & RADIX_TREE_MAP_MASK;
}

Contributors
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matthew wilcox matthew wilcox 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%

/*
 * The maximum index which can be stored in a radix tree
 */


static inline unsigned long shift_maxindex(unsigned int shift)
{
	return (RADIX_TREE_MAP_SIZE << shift) - 1;
}

Contributors
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matthew wilcox matthew wilcox 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%



static inline unsigned long node_maxindex(struct radix_tree_node *node)
{
	return shift_maxindex(node->shift);
}

Contributors
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matthew wilcox matthew wilcox 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%

#ifndef __KERNEL__


static void dump_node(struct radix_tree_node *node, unsigned long index)
{
	unsigned long i;

	pr_debug("radix node: %p offset %d indices %lu-%lu parent %p tags %lx %lx %lx shift %d count %d exceptional %d\n",
		node, node->offset, index, index | node_maxindex(node),
		node->parent,
		node->tags[0][0], node->tags[1][0], node->tags[2][0],
		node->shift, node->count, node->exceptional);

	for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
		unsigned long first = index | (i << node->shift);
		unsigned long last = first | ((1UL << node->shift) - 1);
		void *entry = node->slots[i];
		if (!entry)
			continue;
		if (entry == RADIX_TREE_RETRY) {
			pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n",
					i, first, last, node);
		} else if (!radix_tree_is_internal_node(entry)) {
			pr_debug("radix entry %p offset %ld indices %lu-%lu parent %p\n",
					entry, i, first, last, node);
		} else if (is_sibling_entry(node, entry)) {
			pr_debug("radix sblng %p offset %ld indices %lu-%lu parent %p val %p\n",
					entry, i, first, last, node,
					*(void **)entry_to_node(entry));
		} else {
			dump_node(entry_to_node(entry), first);
		}
	}
}

Contributors
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ross zwisler ross zwisler 180 72.87% 1 12.50%
matthew wilcox matthew wilcox 66 26.72% 6 75.00%
johannes weiner johannes weiner 1 0.40% 1 12.50%
Total 247 100.00% 8 100.00%

/* For debug */


static void radix_tree_dump(struct radix_tree_root *root)
{
	pr_debug("radix root: %p rnode %p tags %x\n",
			root, root->rnode,
			root->gfp_mask >> __GFP_BITS_SHIFT);
	if (!radix_tree_is_internal_node(root->rnode))
		return;
	dump_node(entry_to_node(root->rnode), 0);
}
Contributors
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ross zwisler ross zwisler 48 94.12% 1 25.00%
matthew wilcox matthew wilcox 3 5.88% 3 75.00%
Total 51 100.00% 4 100.00%

#endif

/*
 * 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,
			struct radix_tree_node *parent,
			unsigned int shift, unsigned int offset,
			unsigned int count, unsigned int exceptional)
{
	struct radix_tree_node *ret = NULL;
	gfp_t gfp_mask = root_gfp_mask(root);

	/*
         * Preload code isn't irq safe and it doesn't make sense to use
         * preloading during an interrupt anyway as all the allocations have
         * to be atomic. So just do normal allocation when in interrupt.
         */
	if (!gfpflags_allow_blocking(gfp_mask) && !in_interrupt()) {
		struct radix_tree_preload *rtp;

		/*
                 * Even if the caller has preloaded, try to allocate from the
                 * cache first for the new node to get accounted to the memory
                 * cgroup.
                 */
		ret = kmem_cache_alloc(radix_tree_node_cachep,
				       gfp_mask | __GFP_NOWARN);
		if (ret)
			goto out;

		/*
                 * Provided the caller has preloaded here, we will always
                 * succeed in getting a node here (and never reach
                 * kmem_cache_alloc)
                 */
		rtp = this_cpu_ptr(&radix_tree_preloads);
		if (rtp->nr) {
			ret = rtp->nodes;
			rtp->nodes = ret->private_data;
			ret->private_data = NULL;
			rtp->nr--;
		}
		/*
                 * Update the allocation stack trace as this is more useful
                 * for debugging.
                 */
		kmemleak_update_trace(ret);
		goto out;
	}
	ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
out:
	BUG_ON(radix_tree_is_internal_node(ret));
	if (ret) {
		ret->parent = parent;
		ret->shift = shift;
		ret->offset = offset;
		ret->count = count;
		ret->exceptional = exceptional;
	}
	return ret;
}

Contributors
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matthew wilcox matthew wilcox 59 29.95% 3 23.08%
nick piggin nick piggin 55 27.92% 1 7.69%
andrew morton andrew morton 37 18.78% 2 15.38%
vladimir davydov vladimir davydov 24 12.18% 2 15.38%
kirill a. shutemov kirill a. shutemov 7 3.55% 1 7.69%
catalin marinas catalin marinas 6 3.05% 1 7.69%
jan kara jan kara 4 2.03% 1 7.69%
mel gorman mel gorman 3 1.52% 1 7.69%
christoph lameter christoph lameter 2 1.02% 1 7.69%
Total 197 100.00% 13 100.00%



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);

	/*
         * Must only free zeroed nodes into the slab.  We can be left with
         * non-NULL entries by radix_tree_free_nodes, so clear the entries
         * and tags here.
         */
	memset(node->slots, 0, sizeof(node->slots));
	memset(node->tags, 0, sizeof(node->tags));
	INIT_LIST_HEAD(&node->private_list);

	kmem_cache_free(radix_tree_node_cachep, node);
}

Contributors
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matthew wilcox matthew wilcox 31 41.89% 2 33.33%
nick piggin nick piggin 26 35.14% 2 33.33%
andrew morton andrew morton 15 20.27% 1 16.67%
al viro al viro 2 2.70% 1 16.67%
Total 74 100.00% 6 100.00%


static inline void

radix_tree_node_free(struct radix_tree_node *node)
{
	call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
}

Contributors
Person Tokens Prop Commits CommitProp
nick piggin nick piggin 22 100.00% 2 100.00%
Total 22 100.00% 2 100.00%

/*
 * 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.
 *
 * To make use of this facility, the radix tree must be initialised without
 * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
 */


static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
{
	struct radix_tree_preload *rtp;
	struct radix_tree_node *node;
	int ret = -ENOMEM;

	/*
         * Nodes preloaded by one cgroup can be be used by another cgroup, so
         * they should never be accounted to any particular memory cgroup.
         */
	gfp_mask &= ~__GFP_ACCOUNT;

	preempt_disable();
	rtp = this_cpu_ptr(&radix_tree_preloads);
	while (rtp->nr < nr) {
		preempt_enable();
		node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
		if (node == NULL)
			goto out;
		preempt_disable();
		rtp = this_cpu_ptr(&radix_tree_preloads);
		if (rtp->nr < nr) {
			node->private_data = rtp->nodes;
			rtp->nodes = node;
			rtp->nr++;
		} else {
			kmem_cache_free(radix_tree_node_cachep, node);
		}
	}
	ret = 0;
out:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
nick piggin nick piggin 105 77.78% 2 25.00%
kirill a. shutemov kirill a. shutemov 17 12.59% 2 25.00%
vladimir davydov vladimir davydov 6 4.44% 1 12.50%
christoph lameter christoph lameter 4 2.96% 1 12.50%
jan kara jan kara 2 1.48% 1 12.50%
matthew wilcox matthew wilcox 1 0.74% 1 12.50%
Total 135 100.00% 8 100.00%

/*
 * 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.
 *
 * To make use of this facility, the radix tree must be initialised without
 * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
 */


int radix_tree_preload(gfp_t gfp_mask)
{
	/* Warn on non-sensical use... */
	WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
	return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE);
}
Contributors
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jan kara jan kara 21 80.77% 1 33.33%
mel gorman mel gorman 3 11.54% 1 33.33%
kirill a. shutemov kirill a. shutemov 2 7.69% 1 33.33%
Total 26 100.00% 3 100.00%


EXPORT_SYMBOL(radix_tree_preload);

/*
 * The same as above function, except we don't guarantee preloading happens.
 * We do it, if we decide it helps. On success, return zero with preemption
 * disabled. On error, return -ENOMEM with preemption not disabled.
 */


int radix_tree_maybe_preload(gfp_t gfp_mask)
{
	if (gfpflags_allow_blocking(gfp_mask))
		return __radix_tree_preload(gfp_mask, RADIX_TREE_PRELOAD_SIZE);
	/* Preloading doesn't help anything with this gfp mask, skip it */
	preempt_disable();
	return 0;
}
Contributors
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jan kara jan kara 25 83.33% 1 33.33%
mel gorman mel gorman 3 10.00% 1 33.33%
kirill a. shutemov kirill a. shutemov 2 6.67% 1 33.33%
Total 30 100.00% 3 100.00%


EXPORT_SYMBOL(radix_tree_maybe_preload);

#ifdef CONFIG_RADIX_TREE_MULTIORDER
/*
 * Preload with enough objects to ensure that we can split a single entry
 * of order @old_order into many entries of size @new_order
 */


int radix_tree_split_preload(unsigned int old_order, unsigned int new_order,
							gfp_t gfp_mask)
{
	unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT);
	unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) -
				(new_order / RADIX_TREE_MAP_SHIFT);
	unsigned nr = 0;

	WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
	BUG_ON(new_order >= old_order);

	while (layers--)
		nr = nr * RADIX_TREE_MAP_SIZE + 1;
	return __radix_tree_preload(gfp_mask, top * nr);
}
Contributors
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matthew wilcox matthew wilcox 86 100.00% 1 100.00%
Total 86 100.00% 1 100.00%

#endif

/*
 * The same as function above, but preload number of nodes required to insert
 * (1 << order) continuous naturally-aligned elements.
 */


int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order)
{
	unsigned long nr_subtrees;
	int nr_nodes, subtree_height;

	/* Preloading doesn't help anything with this gfp mask, skip it */
	if (!gfpflags_allow_blocking(gfp_mask)) {
		preempt_disable();
		return 0;
	}

	/*
         * Calculate number and height of fully populated subtrees it takes to
         * store (1 << order) elements.
         */
	nr_subtrees = 1 << order;
	for (subtree_height = 0; nr_subtrees > RADIX_TREE_MAP_SIZE;
			subtree_height++)
		nr_subtrees >>= RADIX_TREE_MAP_SHIFT;

	/*
         * The worst case is zero height tree with a single item at index 0 and
         * then inserting items starting at ULONG_MAX - (1 << order).
         *
         * This requires RADIX_TREE_MAX_PATH nodes to build branch from root to
         * 0-index item.
         */
	nr_nodes = RADIX_TREE_MAX_PATH;

	/* Plus branch to fully populated subtrees. */
	nr_nodes += RADIX_TREE_MAX_PATH - subtree_height;

	/* Root node is shared. */
	nr_nodes--;

	/* Plus nodes required to build subtrees. */
	nr_nodes += nr_subtrees * height_to_maxnodes[subtree_height];

	return __radix_tree_preload(gfp_mask, nr_nodes);
}

Contributors
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kirill a. shutemov kirill a. shutemov 95 100.00% 1 100.00%
Total 95 100.00% 1 100.00%



static unsigned radix_tree_load_root(struct radix_tree_root *root,
		struct radix_tree_node **nodep, unsigned long *maxindex)
{
	struct radix_tree_node *node = rcu_dereference_raw(root->rnode);

	*nodep = node;

	if (likely(radix_tree_is_internal_node(node))) {
		node = entry_to_node(node);
		*maxindex = node_maxindex(node);
		return node->shift + RADIX_TREE_MAP_SHIFT;
	}

	*maxindex = 0;
	return 0;
}

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matthew wilcox matthew wilcox 81 100.00% 4 100.00%
Total 81 100.00% 4 100.00%

/*
 *      Extend a radix tree so it can store key @index.
 */


static int radix_tree_extend(struct radix_tree_root *root,
				unsigned long index, unsigned int shift)
{
	struct radix_tree_node *slot;
	unsigned int maxshift;
	int tag;

	/* Figure out what the shift should be.  */
	maxshift = shift;
	while (index > shift_maxindex(maxshift))
		maxshift += RADIX_TREE_MAP_SHIFT;

	slot = root->rnode;
	if (!slot)
		goto out;

	do {
		struct radix_tree_node *node = radix_tree_node_alloc(root,
							NULL, shift, 0, 1, 0);
		if (!node)
			return -ENOMEM;

		/* Propagate the aggregated tag info into the new root */
		for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
			if (root_tag_get(root, tag))
				tag_set(node, tag, 0);
		}

		BUG_ON(shift > BITS_PER_LONG);
		if (radix_tree_is_internal_node(slot)) {
			entry_to_node(slot)->parent = node;
		} else if (radix_tree_exceptional_entry(slot)) {
			/* Moving an exceptional root->rnode to a node */
			node->exceptional = 1;
		}
		node->slots[0] = slot;
		slot = node_to_entry(node);
		rcu_assign_pointer(root->rnode, slot);
		shift += RADIX_TREE_MAP_SHIFT;
	} while (shift <= maxshift);
out:
	return maxshift + RADIX_TREE_MAP_SHIFT;
}

Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 94 43.93% 2 11.11%
matthew wilcox matthew wilcox 63 29.44% 9 50.00%
hugh dickins hugh dickins 22 10.28% 1 5.56%
johannes weiner johannes weiner 20 9.35% 2 11.11%
nick piggin nick piggin 14 6.54% 3 16.67%
jonathan corbet jonathan corbet 1 0.47% 1 5.56%
Total 214 100.00% 18 100.00%

/**
 *      radix_tree_shrink    -    shrink radix tree to minimum height
 *      @root           radix tree root
 */


static inline void radix_tree_shrink(struct radix_tree_root *root,
				     radix_tree_update_node_t update_node,
				     void *private)
{
	for (;;) {
		struct radix_tree_node *node = root->rnode;
		struct radix_tree_node *child;

		if (!radix_tree_is_internal_node(node))
			break;
		node = entry_to_node(node);

		/*
                 * The candidate node has more than one child, or its child
                 * is not at the leftmost slot, or the child is a multiorder
                 * entry, we cannot shrink.
                 */
		if (node->count != 1)
			break;
		child = node->slots[0];
		if (!child)
			break;
		if (!radix_tree_is_internal_node(child) && node->shift)
			break;

		if (radix_tree_is_internal_node(child))
			entry_to_node(child)->parent = NULL;

		/*
                 * 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
                 * (node->slots[0]), it will be safe to dereference the new
                 * one (root->rnode) as far as dependent read barriers go.
                 */
		root->rnode = child;

		/*
                 * We have a dilemma here. The node's slot[0] must not be
                 * NULLed in case there are concurrent lookups expecting to
                 * find the item. However if this was a bottom-level node,
                 * then it may be subject to the slot pointer being visible
                 * to callers dereferencing it. If item corresponding to
                 * slot[0] is subsequently deleted, these callers would expect
                 * their slot to become empty sooner or later.
                 *
                 * For example, lockless pagecache will look up a slot, deref
                 * the page pointer, and if the page has 0 refcount it means it
                 * was concurrently deleted from pagecache so try the deref
                 * again. Fortunately there is already a requirement for logic
                 * to retry the entire slot lookup -- the indirect pointer
                 * problem (replacing direct root node with an indirect pointer
                 * also results in a stale slot). So tag the slot as indirect
                 * to force callers to retry.
                 */
		node->count = 0;
		if (!radix_tree_is_internal_node(child)) {
			node->slots[0] = RADIX_TREE_RETRY;
			if (update_node)
				update_node(node, private);
		}

		WARN_ON_ONCE(!list_empty(&node->private_list));
		radix_tree_node_free(node);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 101 59.06% 5 31.25%
andrew morton andrew morton 37 21.64% 1 6.25%
matthew wilcox matthew wilcox 29 16.96% 7 43.75%
hugh dickins hugh dickins 2 1.17% 1 6.25%
nick piggin nick piggin 1 0.58% 1 6.25%
christoph lameter christoph lameter 1 0.58% 1 6.25%
Total 171 100.00% 16 100.00%



static void delete_node(struct radix_tree_root *root,
			struct radix_tree_node *node,
			radix_tree_update_node_t update_node, void *private)
{
	do {
		struct radix_tree_node *parent;

		if (node->count) {
			if (node == entry_to_node(root->rnode))
				radix_tree_shrink(root, update_node, private);
			return;
		}

		parent = node->parent;
		if (parent) {
			parent->slots[node->offset] = NULL;
			parent->count--;
		} else {
			root_tag_clear_all(root);
			root->rnode = NULL;
		}

		WARN_ON_ONCE(!list_empty(&node->private_list));
		radix_tree_node_free(node);

		node = parent;
	} while (node);
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 98 76.56% 5 50.00%
matthew wilcox matthew wilcox 26 20.31% 4 40.00%
andrew morton andrew morton 4 3.12% 1 10.00%
Total 128 100.00% 10 100.00%

/**
 *      __radix_tree_create     -       create a slot in a radix tree
 *      @root:          radix tree root
 *      @index:         index key
 *      @order:         index occupies 2^order aligned slots
 *      @nodep:         returns node
 *      @slotp:         returns slot
 *
 *      Create, if necessary, and return the node and slot for an item
 *      at position @index in the radix tree @root.
 *
 *      Until there is more than one item in the tree, no nodes are
 *      allocated and @root->rnode is used as a direct slot instead of
 *      pointing to a node, in which case *@nodep will be NULL.
 *
 *      Returns -ENOMEM, or 0 for success.
 */


int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
			unsigned order, struct radix_tree_node **nodep,
			void ***slotp)
{
	struct radix_tree_node *node = NULL, *child;
	void **slot = (void **)&root->rnode;
	unsigned long maxindex;
	unsigned int shift, offset = 0;
	unsigned long max = index | ((1UL << order) - 1);

	shift = radix_tree_load_root(root, &child, &maxindex);

	/* Make sure the tree is high enough.  */
	if (order > 0 && max == ((1UL << order) - 1))
		max++;
	if (max > maxindex) {
		int error = radix_tree_extend(root, max, shift);
		if (error < 0)
			return error;
		shift = error;
		child = root->rnode;
	}

	while (shift > order) {
		shift -= RADIX_TREE_MAP_SHIFT;
		if (child == NULL) {
			/* Have to add a child node.  */
			child = radix_tree_node_alloc(root, node, shift,
							offset, 0, 0);
			if (!child)
				return -ENOMEM;
			rcu_assign_pointer(*slot, node_to_entry(child));
			if (node)
				node->count++;
		} else if (!radix_tree_is_internal_node(child))
			break;

		/* Go a level down */
		node = entry_to_node(child);
		offset = radix_tree_descend(node, &child, index);
		slot = &node->slots[offset];
	}

	if (nodep)
		*nodep = node;
	if (slotp)
		*slotp = slot;
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 155 54.58% 15 71.43%
andrew morton andrew morton 66 23.24% 2 9.52%
johannes weiner johannes weiner 54 19.01% 1 4.76%
nick piggin nick piggin 8 2.82% 2 9.52%
christoph lameter christoph lameter 1 0.35% 1 4.76%
Total 284 100.00% 21 100.00%

#ifdef CONFIG_RADIX_TREE_MULTIORDER
/*
 * Free any nodes below this node.  The tree is presumed to not need
 * shrinking, and any user data in the tree is presumed to not need a
 * destructor called on it.  If we need to add a destructor, we can
 * add that functionality later.  Note that we may not clear tags or
 * slots from the tree as an RCU walker may still have a pointer into
 * this subtree.  We could replace the entries with RADIX_TREE_RETRY,
 * but we'll still have to clear those in rcu_free.
 */


static void radix_tree_free_nodes(struct radix_tree_node *node)
{
	unsigned offset = 0;
	struct radix_tree_node *child = entry_to_node(node);

	for (;;) {
		void *entry = child->slots[offset];
		if (radix_tree_is_internal_node(entry) &&
					!is_sibling_entry(child, entry)) {
			child = entry_to_node(entry);
			offset = 0;
			continue;
		}
		offset++;
		while (offset == RADIX_TREE_MAP_SIZE) {
			struct radix_tree_node *old = child;
			offset = child->offset + 1;
			child = child->parent;
			WARN_ON_ONCE(!list_empty(&old->private_list));
			radix_tree_node_free(old);
			if (old == entry_to_node(node))
				return;
		}
	}
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 107 81.06% 3 60.00%
johannes weiner johannes weiner 25 18.94% 2 40.00%
Total 132 100.00% 5 100.00%



static inline int insert_entries(struct radix_tree_node *node, void **slot,
				void *item, unsigned order, bool replace)
{
	struct radix_tree_node *child;
	unsigned i, n, tag, offset, tags = 0;

	if (node) {
		if (order > node->shift)
			n = 1 << (order - node->shift);
		else
			n = 1;
		offset = get_slot_offset(node, slot);
	} else {
		n = 1;
		offset = 0;
	}

	if (n > 1) {
		offset = offset & ~(n - 1);
		slot = &node->slots[offset];
	}
	child = node_to_entry(slot);

	for (i = 0; i < n; i++) {
		if (slot[i]) {
			if (replace) {
				node->count--;
				for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
					if (tag_get(node, tag, offset + i))
						tags |= 1 << tag;
			} else
				return -EEXIST;
		}
	}

	for (i = 0; i < n; i++) {
		struct radix_tree_node *old = slot[i];
		if (i) {
			rcu_assign_pointer(slot[i], child);
			for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
				if (tags & (1 << tag))
					tag_clear(node, tag, offset + i);
		} else {
			rcu_assign_pointer(slot[i], item);
			for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
				if (tags & (1 << tag))
					tag_set(node, tag, offset);
		}
		if (radix_tree_is_internal_node(old) &&
					!is_sibling_entry(node, old) &&
					(old != RADIX_TREE_RETRY))
			radix_tree_free_nodes(old);
		if (radix_tree_exceptional_entry(old))
			node->exceptional--;
	}
	if (node) {
		node->count += n;
		if (radix_tree_exceptional_entry(item))
			node->exceptional += n;
	}
	return n;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 390 100.00% 2 100.00%
Total 390 100.00% 2 100.00%

#else


static inline int insert_entries(struct radix_tree_node *node, void **slot,
				void *item, unsigned order, bool replace)
{
	if (*slot)
		return -EEXIST;
	rcu_assign_pointer(*slot, item);
	if (node) {
		node->count++;
		if (radix_tree_exceptional_entry(item))
			node->exceptional++;
	}
	return 1;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 70 100.00% 1 100.00%
Total 70 100.00% 1 100.00%

#endif

/**
 *      __radix_tree_insert    -    insert into a radix tree
 *      @root:          radix tree root
 *      @index:         index key
 *      @order:         key covers the 2^order indices around index
 *      @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,
			unsigned order, void *item)
{
	struct radix_tree_node *node;
	void **slot;
	int error;

	BUG_ON(radix_tree_is_internal_node(item));

	error = __radix_tree_create(root, index, order, &node, &slot);
	if (error)
		return error;

	error = insert_entries(node, slot, item, order, false);
	if (error < 0)
		return error;

	if (node) {
		unsigned offset = get_slot_offset(node, slot);
		BUG_ON(tag_get(node, 0, offset));
		BUG_ON(tag_get(node, 1, offset));
		BUG_ON(tag_get(node, 2, offset));
	} else {
		BUG_ON(root_tags_get(root));
	}

	return 0;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 79 50.64% 3 37.50%
johannes weiner johannes weiner 31 19.87% 1 12.50%
andrew morton andrew morton 27 17.31% 3 37.50%
nick piggin nick piggin 19 12.18% 1 12.50%
Total 156 100.00% 8 100.00%


EXPORT_SYMBOL(__radix_tree_insert);

/**
 *      __radix_tree_lookup     -       lookup an item in a radix tree
 *      @root:          radix tree root
 *      @index:         index key
 *      @nodep:         returns node
 *      @slotp:         returns slot
 *
 *      Lookup and return the item at position @index in the radix
 *      tree @root.
 *
 *      Until there is more than one item in the tree, no nodes are
 *      allocated and @root->rnode is used as a direct slot instead of
 *      pointing to a node, in which case *@nodep will be NULL.
 */


void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,
			  struct radix_tree_node **nodep, void ***slotp)
{
	struct radix_tree_node *node, *parent;
	unsigned long maxindex;
	void **slot;

 restart:
	parent = NULL;
	slot = (void **)&root->rnode;
	radix_tree_load_root(root, &node, &maxindex);
	if (index > maxindex)
		return NULL;

	while (radix_tree_is_internal_node(node)) {
		unsigned offset;

		if (node == RADIX_TREE_RETRY)
			goto restart;
		parent = entry_to_node(node);
		offset = radix_tree_descend(parent, &node, index);
		slot = parent->slots + offset;
	}

	if (nodep)
		*nodep = parent;
	if (slotp)
		*slotp = slot;
	return node;
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 56 37.09% 5 35.71%
johannes weiner johannes weiner 47 31.13% 2 14.29%
nick piggin nick piggin 22 14.57% 3 21.43%
andrew morton andrew morton 19 12.58% 2 14.29%
huang shijie huang shijie 4 2.65% 1 7.14%
hans reiser hans reiser 3 1.99% 1 7.14%
Total 151 100.00% 14 100.00%

/**
 *      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)
{
	void **slot;

	if (!__radix_tree_lookup(root, index, NULL, &slot))
		return NULL;
	return slot;
}
Contributors
Person Tokens Prop Commits CommitProp
huang shijie huang shijie 22 52.38% 1 33.33%
johannes weiner johannes weiner 18 42.86% 1 33.33%
hans reiser hans reiser 2 4.76% 1 33.33%
Total 42 100.00% 3 100.00%


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.
 *
 *      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.
 */


void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
{
	return __radix_tree_lookup(root, index, NULL, NULL);
}
Contributors
Person Tokens Prop Commits CommitProp
hans reiser hans reiser 15 55.56% 1 16.67%
nick piggin nick piggin 4 14.81% 2 33.33%
johannes weiner johannes weiner 4 14.81% 1 16.67%
huang shijie huang shijie 3 11.11% 1 16.67%
andrew morton andrew morton 1 3.70% 1 16.67%
Total 27 100.00% 6 100.00%


EXPORT_SYMBOL(radix_tree_lookup);



static inline int slot_count(struct radix_tree_node *node,
						void **slot)
{
	int n = 1;
#ifdef CONFIG_RADIX_TREE_MULTIORDER
	void *ptr = node_to_entry(slot);
	unsigned offset = get_slot_offset(node, slot);
	int i;

	for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) {
		if (node->slots[offset + i] != ptr)
			break;
		n++;
	}
#endif
	return n;
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 86 100.00% 1 100.00%
Total 86 100.00% 1 100.00%



static void replace_slot(struct radix_tree_root *root,
			 struct radix_tree_node *node,
			 void **slot, void *item,
			 bool warn_typeswitch)
{
	void *old = rcu_dereference_raw(*slot);
	int count, exceptional;

	WARN_ON_ONCE(radix_tree_is_internal_node(item));

	count = !!item - !!old;
	exceptional = !!radix_tree_exceptional_entry(item) -
		      !!radix_tree_exceptional_entry(old);

	WARN_ON_ONCE(warn_typeswitch && (count || exceptional));

	if (node) {
		node->count += count;
		if (exceptional) {
			exceptional *= slot_count(node, slot);
			node->exceptional += exceptional;
		}
	}

	rcu_assign_pointer(*slot, item);
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 114 88.37% 3 75.00%
matthew wilcox matthew wilcox 15 11.63% 1 25.00%
Total 129 100.00% 4 100.00%



static inline void delete_sibling_entries(struct radix_tree_node *node,
						void **slot)
{
#ifdef CONFIG_RADIX_TREE_MULTIORDER
	bool exceptional = radix_tree_exceptional_entry(*slot);
	void *ptr = node_to_entry(slot);
	unsigned offset = get_slot_offset(node, slot);
	int i;

	for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) {
		if (node->slots[offset + i] != ptr)
			break;
		node->slots[offset + i] = NULL;
		node->count--;
		if (exceptional)
			node->exceptional--;
	}
#endif
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 109 100.00% 1 100.00%
Total 109 100.00% 1 100.00%

/**
 * __radix_tree_replace         - replace item in a slot
 * @root:               radix tree root
 * @node:               pointer to tree node
 * @slot:               pointer to slot in @node
 * @item:               new item to store in the slot.
 * @update_node:        callback for changing leaf nodes
 * @private:            private data to pass to @update_node
 *
 * For use with __radix_tree_lookup().  Caller must hold tree write locked
 * across slot lookup and replacement.
 */


void __radix_tree_replace(struct radix_tree_root *root,
			  struct radix_tree_node *node,
			  void **slot, void *item,
			  radix_tree_update_node_t update_node, void *private)
{
	if (!item)
		delete_sibling_entries(node, slot);
	/*
         * This function supports replacing exceptional entries and
         * deleting entries, but that needs accounting against the
         * node unless the slot is root->rnode.
         */
	replace_slot(root, node, slot, item,
		     !node && slot != (void **)&root->rnode);

	if (!node)
		return;

	if (update_node)
		update_node(node, private);

	delete_node(root, node, update_node, private);
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 86 87.76% 4 80.00%
matthew wilcox matthew wilcox 12 12.24% 1 20.00%
Total 98 100.00% 5 100.00%

/**
 * radix_tree_replace_slot      - replace item in a slot
 * @root:       radix tree root
 * @slot:       pointer to slot
 * @item:       new item to store in the slot.
 *
 * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(),
 * radix_tree_gang_lookup_tag_slot().  Caller must hold tree write locked
 * across slot lookup and replacement.
 *
 * NOTE: This cannot be used to switch between non-entries (empty slots),
 * regular entries, and exceptional entries, as that requires accounting
 * inside the radix tree node. When switching from one type of entry or
 * deleting, use __radix_tree_lookup() and __radix_tree_replace() or
 * radix_tree_iter_replace().
 */


void radix_tree_replace_slot(struct radix_tree_root *root,
			     void **slot, void *item)
{
	replace_slot(root, NULL, slot, item, true);
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 32 100.00% 2 100.00%
Total 32 100.00% 2 100.00%

/**
 * radix_tree_iter_replace - replace item in a slot
 * @root:       radix tree root
 * @slot:       pointer to slot
 * @item:       new item to store in the slot.
 *
 * For use with radix_tree_split() and radix_tree_for_each_slot().
 * Caller must hold tree write locked across split and replacement.
 */


void radix_tree_iter_replace(struct radix_tree_root *root,
		const struct radix_tree_iter *iter, void **slot, void *item)
{
	__radix_tree_replace(root, iter->node, slot, item, NULL, NULL);
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 42 100.00% 1 100.00%
Total 42 100.00% 1 100.00%

#ifdef CONFIG_RADIX_TREE_MULTIORDER
/**
 * radix_tree_join - replace multiple entries with one multiorder entry
 * @root: radix tree root
 * @index: an index inside the new entry
 * @order: order of the new entry
 * @item: new entry
 *
 * Call this function to replace several entries with one larger entry.
 * The existing entries are presumed to not need freeing as a result of
 * this call.
 *
 * The replacement entry will have all the tags set on it that were set
 * on any of the entries it is replacing.
 */


int radix_tree_join(struct radix_tree_root *root, unsigned long index,
			unsigned order, void *item)
{
	struct radix_tree_node *node;
	void **slot;
	int error;

	BUG_ON(radix_tree_is_internal_node(item));

	error = __radix_tree_create(root, index, order, &node, &slot);
	if (!error)
		error = insert_entries(node, slot, item, order, true);
	if (error > 0)
		error = 0;

	return error;
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 92 100.00% 1 100.00%
Total 92 100.00% 1 100.00%

/**
 * radix_tree_split - Split an entry into smaller entries
 * @root: radix tree root
 * @index: An index within the large entry
 * @order: Order of new entries
 *
 * Call this function as the first step in replacing a multiorder entry
 * with several entries of lower order.  After this function returns,
 * loop over the relevant portion of the tree using radix_tree_for_each_slot()
 * and call radix_tree_iter_replace() to set up each new entry.
 *
 * The tags from this entry are replicated to all the new entries.
 *
 * The radix tree should be locked against modification during the entire
 * replacement operation.  Lock-free lookups will see RADIX_TREE_RETRY which
 * should prompt RCU walkers to restart the lookup from the root.
 */


int radix_tree_split(struct radix_tree_root *root, unsigned long index,
				unsigned order)
{
	struct radix_tree_node *parent, *node, *child;
	void **slot;
	unsigned int offset, end;
	unsigned n, tag, tags = 0;

	if (!__radix_tree_lookup(root, index, &parent, &slot))
		return -ENOENT;
	if (!parent)
		return -ENOENT;

	offset = get_slot_offset(parent, slot);

	for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
		if (tag_get(parent, tag, offset))
			tags |= 1 << tag;

	for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) {
		if (!is_sibling_entry(parent, parent->slots[end]))
			break;
		for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
			if (tags & (1 << tag))
				tag_set(parent, tag, end);
		/* rcu_assign_pointer ensures tags are set before RETRY */
		rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY);
	}
	rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY);
	parent->exceptional -= (end - offset);

	if (order == parent->shift)
		return 0;
	if (order > parent->shift) {
		while (offset < end)
			offset += insert_entries(parent, &parent->slots[offset],
					RADIX_TREE_RETRY, order, true);
		return 0;
	}

	node = parent;

	for (;;) {
		if (node->shift > order) {
			child = radix_tree_node_alloc(root, node,
					node->shift - RADIX_TREE_MAP_SHIFT,
					offset, 0, 0);
			if (!child)
				goto nomem;
			if (node != parent) {
				node->count++;
				node->slots[offset] = node_to_entry(child);
				for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
					if (tags & (1 << tag))
						tag_set(node, tag, offset);
			}

			node = child;
			offset = 0;
			continue;
		}

		n = insert_entries(node, &node->slots[offset],
					RADIX_TREE_RETRY, order, false);
		BUG_ON(n > RADIX_TREE_MAP_SIZE);

		for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
			if (tags & (1 << tag))
				tag_set(node, tag, offset);
		offset += n;

		while (offset == RADIX_TREE_MAP_SIZE) {
			if (node == parent)
				break;
			offset = node->offset;
			child = node;
			node = node->parent;
			rcu_assign_pointer(node->slots[offset],
						node_to_entry(child));
			offset++;
		}
		if ((node == parent) && (offset == end))
			return 0;
	}

 nomem:
	/* Shouldn't happen; did user forget to preload? */
	/* TODO: free all the allocated nodes */
	WARN_ON(1);
	return -ENOMEM;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 468 88.97% 4 50.00%
andrew morton andrew morton 23 4.37% 1 12.50%
ross zwisler ross zwisler 22 4.18% 1 12.50%
nick piggin nick piggin 12 2.28% 1 12.50%
jonathan corbet jonathan corbet 1 0.19% 1 12.50%
Total 526 100.00% 8 100.00%

#endif

/**
 *      radix_tree_tag_set - set a tag on a radix tree node
 *      @root:          radix tree root
 *      @index:         index key
 *      @tag:           tag index
 *
 *      Set the search tag (which must be < RADIX_TREE_MAX_TAGS)
 *      corresponding to @index in the radix tree.  From
 *      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,
			unsigned long index, unsigned int tag)
{
	struct radix_tree_node *node, *parent;
	unsigned long maxindex;

	radix_tree_load_root(root, &node, &maxindex);
	BUG_ON(index > maxindex);

	while (radix_tree_is_internal_node(node)) {
		unsigned offset;

		parent = entry_to_node(node);
		offset = radix_tree_descend(parent, &node, index);
		BUG_ON(!node);

		if (!tag_get(parent, tag, offset))
			tag_set(parent, tag, offset);
	}

	/* set the root's tag bit */
	if (!root_tag_get(root, tag))
		root_tag_set(root, tag);

	return node;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 128 100.00% 1 100.00%
Total 128 100.00% 1 100.00%


EXPORT_SYMBOL(radix_tree_tag_set);



static void node_tag_clear(struct radix_tree_root *root,
				struct radix_tree_node *node,
				unsigned int tag, unsigned int offset)
{
	while (node) {
		if (!tag_get(node, tag, offset))
			return;
		tag_clear(node, tag, offset);
		if (any_tag_set(node, tag))
			return;

		offset = node->offset;
		node = node->parent;
	}

	/* clear the root's tag bit */
	if (root_tag_get(root, tag))
		root_tag_clear(root, tag);
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 91 100.00% 1 100.00%
Total 91 100.00% 1 100.00%



static void node_tag_set(struct radix_tree_root *root,
				struct radix_tree_node *node,
				unsigned int tag, unsigned int offset)
{
	while (node) {
		if (tag_get(node, tag, offset))
			return;
		tag_set(node, tag, offset);
		offset = node->offset;
		node = node->parent;
	}

	if (!root_tag_get(root, tag))
		root_tag_set(root, tag);
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 80 100.00% 1 100.00%
Total 80 100.00% 1 100.00%

/**
 * radix_tree_iter_tag_set - set a tag on the current iterator entry
 * @root:       radix tree root
 * @iter:       iterator state
 * @tag:        tag to set
 */


void radix_tree_iter_tag_set(struct radix_tree_root *root,
			const struct radix_tree_iter *iter, unsigned int tag)
{
	node_tag_set(root, iter->node, tag, iter_offset(iter));
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%

/**
 *      radix_tree_tag_clear - clear a tag on a radix tree node
 *      @root:          radix tree root
 *      @index:         index key
 *      @tag:           tag index
 *
 *      Clear the search tag (which must be < RADIX_TREE_MAX_TAGS)
 *      corresponding to @index in the radix tree.  If 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,
			unsigned long index, unsigned int tag)
{
	struct radix_tree_node *node, *parent;
	unsigned long maxindex;
	int uninitialized_var(offset);

	radix_tree_load_root(root, &node, &maxindex);
	if (index > maxindex)
		return NULL;

	parent = NULL;

	while (radix_tree_is_internal_node(node)) {
		parent = entry_to_node(node);
		offset = radix_tree_descend(parent, &node, index);
	}

	if (node)
		node_tag_clear(root, parent, tag, offset);

	return node;
}
Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 46 42.99% 1 8.33%
ross zwisler ross zwisler 39 36.45% 1 8.33%
hugh dickins hugh dickins 8 7.48% 1 8.33%
matthew wilcox matthew wilcox 8 7.48% 5 41.67%
nick piggin nick piggin 3 2.80% 2 16.67%
christoph lameter christoph lameter 2 1.87% 1 8.33%
jonathan corbet jonathan corbet 1 0.93% 1 8.33%
Total 107 100.00% 12 100.00%


EXPORT_SYMBOL(radix_tree_tag_clear);

/**
 * radix_tree_tag_get - get a tag on a radix tree node
 * @root:               radix tree root
 * @index:              index key
 * @tag:                tag index (< RADIX_TREE_MAX_TAGS)
 *
 * Return values:
 *
 *  0: tag not present or not set
 *  1: tag set
 *
 * 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.
 */


int radix_tree_tag_get(struct radix_tree_root *root,
			unsigned long index, unsigned int tag)
{
	struct radix_tree_node *node, *parent;
	unsigned long maxindex;

	if (!root_tag_get(root, tag))
		return 0;

	radix_tree_load_root(root, &node, &maxindex);
	if (index > maxindex)
		return 0;
	if (node == NULL)
		return 0;

	while (radix_tree_is_internal_node(node)) {
		unsigned offset;

		parent = entry_to_node(node);
		offset = radix_tree_descend(parent, &node, index);

		if (!node)
			return 0;
		if (!tag_get(parent, tag, offset))
			return 0;
		if (node == RADIX_TREE_RETRY)
			break;
	}

	return 1;
}
Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 48 35.29% 1 9.09%
ross zwisler ross zwisler 42 30.88% 1 9.09%
nick piggin nick piggin 34 25.00% 3 27.27%
matthew wilcox matthew wilcox 8 5.88% 4 36.36%
hugh dickins hugh dickins 3 2.21% 1 9.09%
jonathan corbet jonathan corbet 1 0.74% 1 9.09%
Total 136 100.00% 11 100.00%


EXPORT_SYMBOL(radix_tree_tag_get);



static inline void __set_iter_shift(struct radix_tree_iter *iter,
					unsigned int shift)
{
#ifdef CONFIG_RADIX_TREE_MULTIORDER
	iter->shift = shift;
#endif
}

Contributors
Person Tokens Prop Commits CommitProp
ross zwisler ross zwisler 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%

/* Construct iter->tags bit-mask from node->tags[tag] array */


static void set_iter_tags(struct radix_tree_iter *iter,
				struct radix_tree_node *node, unsigned offset,
				unsigned tag)
{
	unsigned tag_long = offset / BITS_PER_LONG;
	unsigned tag_bit  = offset % BITS_PER_LONG;

	iter->tags = node->tags[tag][tag_long] >> tag_bit;

	/* This never happens if RADIX_TREE_TAG_LONGS == 1 */
	if (tag_long < RADIX_TREE_TAG_LONGS - 1) {
		/* Pick tags from next element */
		if (tag_bit)
			iter->tags |= node->tags[tag][tag_long + 1] <<
						(BITS_PER_LONG - tag_bit);
		/* Clip chunk size, here only BITS_PER_LONG tags */
		iter->next_index = __radix_tree_iter_add(iter, BITS_PER_LONG);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 60 58.82% 1 33.33%
konstantin khlebnikov konstantin khlebnikov 36 35.29% 1 33.33%
ross zwisler ross zwisler 6 5.88% 1 33.33%
Total 102 100.00% 3 100.00%

#ifdef CONFIG_RADIX_TREE_MULTIORDER


static void **skip_siblings(struct radix_tree_node **nodep,
			void **slot, struct radix_tree_iter *iter)
{
	void *sib = node_to_entry(slot - 1);

	while (iter->index < iter->next_index) {
		*nodep = rcu_dereference_raw(*slot);
		if (*nodep && *nodep != sib)
			return slot;
		slot++;
		iter->index = __radix_tree_iter_add(iter, 1);
		iter->tags >>= 1;
	}

	*nodep = NULL;
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 97 100.00% 2 100.00%
Total 97 100.00% 2 100.00%



void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
					unsigned flags)
{
	unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
	struct radix_tree_node *node = rcu_dereference_raw(*slot);

	slot = skip_siblings(&node, slot, iter);

	while (radix_tree_is_internal_node(node)) {
		unsigned offset;
		unsigned long next_index;

		if (node == RADIX_TREE_RETRY)
			return slot;
		node = entry_to_node(node);
		iter->node = node;
		iter->shift = node->shift;

		if (flags & RADIX_TREE_ITER_TAGGED) {
			offset = radix_tree_find_next_bit(node, tag, 0);
			if (offset == RADIX_TREE_MAP_SIZE)
				return NULL;
			slot = &node->slots[offset];
			iter->index = __radix_tree_iter_add(iter, offset);
			set_iter_tags(iter, node, offset, tag);
			node = rcu_dereference_raw(*slot);
		} else {
			offset = 0;
			slot = &node->slots[0];
			for (;;) {
				node = rcu_dereference_raw(*slot);
				if (node)
					break;
				slot++;
				offset++;
				if (offset == RADIX_TREE_MAP_SIZE)
					return NULL;
			}
			iter->index = __radix_tree_iter_add(iter, offset);
		}
		if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0))
			goto none;
		next_index = (iter->index | shift_maxindex(iter->shift)) + 1;
		if (next_index < iter->next_index)
			iter->next_index = next_index;
	}

	return slot;
 none:
	iter->next_index = 0;
	return NULL;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 289 100.00% 2 100.00%
Total 289 100.00% 2 100.00%


EXPORT_SYMBOL(__radix_tree_next_slot);
#else


static void **skip_siblings(struct radix_tree_node **nodep,
			void **slot, struct radix_tree_iter *iter)
{
	return slot;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%

#endif



void **radix_tree_iter_resume(void **slot, struct radix_tree_iter *iter)
{
	struct radix_tree_node *node;

	slot++;
	iter->index = __radix_tree_iter_add(iter, 1);
	node = rcu_dereference_raw(*slot);
	skip_siblings(&node, slot, iter);
	iter->next_index = iter->index;
	iter->tags = 0;
	return NULL;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 71 100.00% 1 100.00%
Total 71 100.00% 1 100.00%


EXPORT_SYMBOL(radix_tree_iter_resume);

/**
 * radix_tree_next_chunk - find next chunk of slots for iteration
 *
 * @root:       radix tree root
 * @iter:       iterator state
 * @flags:      RADIX_TREE_ITER_* flags and tag index
 * Returns:     pointer to chunk first slot, or NULL if iteration is over
 */


void **radix_tree_next_chunk(struct radix_tree_root *root,
			     struct radix_tree_iter *iter, unsigned flags)
{
	unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
	struct radix_tree_node *node, *child;
	unsigned long index, offset, maxindex;

	if ((flags & RADIX_TREE_ITER_TAGGED) && !root_tag_get(root, tag))
		return NULL;

	/*
         * Catch next_index overflow after ~0UL. iter->index never overflows
         * during iterating; it can be zero only at the beginning.
         * And we cannot overflow iter->next_index in a single step,
         * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG.
         *
         * This condition also used by radix_tree_next_slot() to stop
         * contiguous iterating, and forbid switching to the next chunk.
         */
	index = iter->next_index;
	if (!index && iter->index)
		return NULL;

 restart:
	radix_tree_load_root(root, &child, &maxindex);
	if (index > maxindex)
		return NULL;
	if (!child)
		return NULL;

	if (!radix_tree_is_internal_node(child)) {
		/* Single-slot tree */
		iter->index = index;
		iter->next_index = maxindex + 1;
		iter->tags = 1;
		iter->node = NULL;
		__set_iter_shift(iter, 0);
		return (void **)&root->rnode;
	}

	do {
		node = entry_to_node(child);
		offset = radix_tree_descend(node, &child, index);

		if ((flags & RADIX_TREE_ITER_TAGGED) ?
				!tag_get(node, tag, offset) : !child) {
			/* Hole detected */
			if (flags & RADIX_TREE_ITER_CONTIG)
				return NULL;

			if (flags & RADIX_TREE_ITER_TAGGED)
				offset = radix_tree_find_next_bit(node, tag,
						offset + 1);
			else
				while (++offset	< RADIX_TREE_MAP_SIZE) {
					void *slot = node->slots[offset];
					if (is_sibling_entry(node, slot))
						continue;
					if (slot)
						break;
				}
			index &= ~node_maxindex(node);
			index += offset << node->shift;
			/* Overflow after ~0UL */
			if (!index)
				return NULL;
			if (offset == RADIX_TREE_MAP_SIZE)
				goto restart;
			child = rcu_dereference_raw(node->slots[offset]);
		}

		if (!child)
			goto restart;
		if (child == RADIX_TREE_RETRY)
			break;
	} while (radix_tree_is_internal_node(child));

	/* Update the iterator state */
	iter->index = (index &~ node_maxindex(node)) | (offset << node->shift);
	iter->next_index = (index | node_maxindex(node)) + 1;
	iter->node = node;
	__set_iter_shift(iter, node->shift);

	if (flags & RADIX_TREE_ITER_TAGGED)
		set_iter_tags(iter, node, offset, tag);

	return node->slots + offset;
}
Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 238 56.40% 8 80.00%
konstantin khlebnikov konstantin khlebnikov 144 34.12% 1 10.00%
ross zwisler ross zwisler 40 9.48% 1 10.00%
Total 422 100.00% 10 100.00%


EXPORT_SYMBOL(radix_tree_next_chunk);

/**
 *      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.
 *
 *      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'.
 */

unsigned int

radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
			unsigned long first_index, unsigned int max_items)
{
	struct radix_tree_iter iter;
	void **slot;
	unsigned int ret = 0;

	if (unlikely(!max_items))
		return 0;

	radix_tree_for_each_slot(slot, root, &iter, first_index) {
		results[ret] = rcu_dereference_raw(*slot);
		if (!results[ret])
			continue;
		if (radix_tree_is_internal_node(results[ret])) {
			slot = radix_tree_iter_retry(&iter);
			continue;
		}
		if (++ret == max_items)
			break;
	}

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
nick piggin nick piggin 50 43.86% 1 20.00%
konstantin khlebnikov konstantin khlebnikov 42 36.84% 1 20.00%
matthew wilcox matthew wilcox 21 18.42% 2 40.00%
paul e. mckenney paul e. mckenney 1 0.88% 1 20.00%
Total 114 100.00% 5 100.00%


EXPORT_SYMBOL(radix_tree_gang_lookup);

/**
 *      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
 *      @indices:       where their indices should be placed (but usually NULL)
 *      @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 *indices,
			unsigned long first_index, unsigned int max_items)
{
	struct radix_tree_iter iter;
	void **slot;
	unsigned int ret = 0;

	if (unlikely(!max_items))
		return 0;

	radix_tree_for_each_slot(slot, root, &iter, first_index) {
		results[ret] = slot;
		if (indices)
			indices[ret] = iter.index;
		if (++ret == max_items)
			break;
	}

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
konstantin khlebnikov konstantin khlebnikov 69 69.70% 1 25.00%
nick piggin nick piggin 25 25.25% 1 25.00%
andrew morton andrew morton 5 5.05% 2 50.00%
Total 99 100.00% 4 100.00%


EXPORT_SYMBOL(radix_tree_gang_lookup_slot);

/**
 *      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
 *      @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 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,
		unsigned long first_index, unsigned int max_items,
		unsigned int tag)
{
	struct radix_tree_iter iter;
	void **slot;
	unsigned int ret = 0;

	if (unlikely(!max_items))
		return 0;

	radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
		results[ret] = rcu_dereference_raw(*slot);
		if (!results[ret])
			continue;
		if (radix_tree_is_internal_node(results[ret])) {
			slot = radix_tree_iter_retry(&iter);
			continue;
		}
		if (++ret == max_items)
			break;
	}

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
konstantin khlebnikov konstantin khlebnikov 39 32.50% 1 10.00%
matthew wilcox matthew wilcox 33 27.50% 6 60.00%
hugh dickins hugh dickins 24 20.00% 1 10.00%
nick piggin nick piggin 23 19.17% 1 10.00%
paul e. mckenney paul e. mckenney 1 0.83% 1 10.00%
Total 120 100.00% 10 100.00%


EXPORT_SYMBOL(radix_tree_gang_lookup_tag);

/**
 *      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_iter iter;
	void **slot;
	unsigned int ret = 0;

	if (unlikely(!max_items))
		return 0;

	radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
		results[ret] = slot;
		if (++ret == max_items)
			break;
	}

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
konstantin khlebnikov konstantin khlebnikov 42 48.28% 1 33.33%
hugh dickins hugh dickins 31 35.63% 1 33.33%
nick piggin nick piggin 14 16.09% 1 33.33%
Total 87 100.00% 3 100.00%


EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);

/**
 *      __radix_tree_delete_node    -    try to free node after clearing a slot
 *      @root:          radix tree root
 *      @node:          node containing @index
 *      @update_node:   callback for changing leaf nodes
 *      @private:       private data to pass to @update_node
 *
 *      After clearing the slot at @index in @node from radix tree
 *      rooted at @root, call this function to attempt freeing the
 *      node and shrinking the tree.
 */


void __radix_tree_delete_node(struct radix_tree_root *root,
			      struct radix_tree_node *node,
			      radix_tree_update_node_t update_node,
			      void *private)
{
	delete_node(root, node, update_node, private);
}

Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 20 60.61% 5 55.56%
andrew morton andrew morton 8 24.24% 1 11.11%
nick piggin nick piggin 3 9.09% 2 22.22%
hugh dickins hugh dickins 2 6.06% 1 11.11%
Total 33 100.00% 9 100.00%

/**
 *      radix_tree_delete_item    -    delete an item from a radix tree
 *      @root:          radix tree root
 *      @index:         index key
 *      @item:          expected item
 *
 *      Remove @item at @index from the radix tree rooted at @root.
 *
 *      Returns the address of the deleted item, or NULL if it was not present
 *      or the entry at the given @index was not @item.
 */


void *radix_tree_delete_item(struct radix_tree_root *root,
			     unsigned long index, void *item)
{
	struct radix_tree_node *node;
	unsigned int offset;
	void **slot;
	void *entry;
	int tag;

	entry = __radix_tree_lookup(root, index, &node, &slot);
	if (!entry)
		return NULL;

	if (item && entry != item)
		return NULL;

	if (!node) {
		root_tag_clear_all(root);
		root->rnode = NULL;
		return entry;
	}

	offset = get_slot_offset(node, slot);

	/* Clear all tags associated with the item to be deleted.  */
	for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
		node_tag_clear(root, node, tag, offset);

	__radix_tree_replace(root, node, slot, NULL, NULL, NULL);

	return entry;
}
Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 98 66.67% 4 26.67%
nick piggin nick piggin 20 13.61% 3 20.00%
andrew morton andrew morton 16 10.88% 3 20.00%
matthew wilcox matthew wilcox 10 6.80% 2 13.33%
jonathan corbet jonathan corbet 1 0.68% 1 6.67%
christoph lameter christoph lameter 1 0.68% 1 6.67%
hugh dickins hugh dickins 1 0.68% 1 6.67%
Total 147 100.00% 15 100.00%


EXPORT_SYMBOL(radix_tree_delete_item);

/**
 *      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)
{
	return radix_tree_delete_item(root, index, NULL);
}
Contributors
Person Tokens Prop Commits CommitProp
johannes weiner johannes weiner 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%


EXPORT_SYMBOL(radix_tree_delete);



void radix_tree_clear_tags(struct radix_tree_root *root,
			   struct radix_tree_node *node,
			   void **slot)
{
	if (node) {
		unsigned int tag, offset = get_slot_offset(node, slot);
		for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
			node_tag_clear(root, node, tag, offset);
	} else {
		/* Clear root node tags */
		root->gfp_mask &= __GFP_BITS_MASK;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 68 93.15% 1 50.00%
johannes weiner johannes weiner 5 6.85% 1 50.00%
Total 73 100.00% 2 100.00%

/**
 *      radix_tree_tagged - test whether any items in the tree are tagged
 *      @root:          radix tree root
 *      @tag:           tag to test
 */


int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag)
{
	return root_tag_get(root, tag);
}
Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 15 68.18% 1 25.00%
nick piggin nick piggin 6 27.27% 2 50.00%
jonathan corbet jonathan corbet 1 4.55% 1 25.00%
Total 22 100.00% 4 100.00%


EXPORT_SYMBOL(radix_tree_tagged);


static void

radix_tree_node_ctor(void *arg)
{
	struct radix_tree_node *node = arg;

	memset(node, 0, sizeof(*node));
	INIT_LIST_HEAD(&node->private_list);
}

Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 18 47.37% 1 33.33%
johannes weiner johannes weiner 18 47.37% 1 33.33%
christoph lameter christoph lameter 2 5.26% 1 33.33%
Total 38 100.00% 3 100.00%



static __init unsigned long __maxindex(unsigned int height)
{
	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;
}

Contributors
Person Tokens Prop Commits CommitProp
kirill a. shutemov kirill a. shutemov 52 100.00% 1 100.00%
Total 52 100.00% 1 100.00%



static __init void radix_tree_init_maxnodes(void)
{
	unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1];
	unsigned int i, j;

	for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++)
		height_to_maxindex[i] = __maxindex(i);
	for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) {
		for (j = i; j > 0; j--)
			height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
kirill a. shutemov kirill a. shutemov 95 100.00% 1 100.00%
Total 95 100.00% 1 100.00%



static int radix_tree_cpu_dead(unsigned int cpu)
{
	struct radix_tree_preload *rtp;
	struct radix_tree_node *node;

	/* Free per-cpu pool of preloaded nodes */
	rtp = &per_cpu(radix_tree_preloads, cpu);
	while (rtp->nr) {
		node = rtp->nodes;
		rtp->nodes = node->private_data;
		kmem_cache_free(radix_tree_node_cachep, node);
		rtp->nr--;
	}
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
rusty russell rusty russell 46 67.65% 1 25.00%
kirill a. shutemov kirill a. shutemov 17 25.00% 1 25.00%
sebastian andrzej siewior sebastian andrzej siewior 4 5.88% 1 25.00%
matthew wilcox matthew wilcox 1 1.47% 1 25.00%
Total 68 100.00% 4 100.00%



void __init radix_tree_init(void)
{
	int ret;
	radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
			sizeof(struct radix_tree_node), 0,
			SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
			radix_tree_node_ctor);
	radix_tree_init_maxnodes();
	ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead",
					NULL, radix_tree_cpu_dead);
	WARN_ON(ret < 0);
}
Contributors
Person Tokens Prop Commits CommitProp
andrew morton andrew morton 27 49.09% 2 33.33%
sebastian andrzej siewior sebastian andrzej siewior 18 32.73% 1 16.67%
rusty russell rusty russell 5 9.09% 1 16.67%
kirill a. shutemov kirill a. shutemov 3 5.45% 1 16.67%
christoph lameter christoph lameter 2 3.64% 1 16.67%
Total 55 100.00% 6 100.00%

Overall Contributors
Person Tokens Prop Commits CommitProp
matthew wilcox matthew wilcox 3793 49.97% 39 37.86%
johannes weiner johannes weiner 808 10.64% 10 9.71%
nick piggin nick piggin 760 10.01% 11 10.68%
andrew morton andrew morton 633 8.34% 9 8.74%
konstantin khlebnikov konstantin khlebnikov 489 6.44% 2 1.94%
ross zwisler ross zwisler 407 5.36% 5 4.85%
kirill a. shutemov kirill a. shutemov 304 4.00% 2 1.94%
hugh dickins hugh dickins 96 1.26% 3 2.91%
jan kara jan kara 61 0.80% 1 0.97%
rusty russell rusty russell 54 0.71% 1 0.97%
huang shijie huang shijie 30 0.40% 1 0.97%
vladimir davydov vladimir davydov 30 0.40% 2 1.94%
linus torvalds linus torvalds 29 0.38% 2 1.94%
hans reiser hans reiser 25 0.33% 1 0.97%
sebastian andrzej siewior sebastian andrzej siewior 22 0.29% 1 0.97%
christoph lameter christoph lameter 17 0.22% 5 4.85%
mel gorman mel gorman 11 0.14% 1 0.97%
catalin marinas catalin marinas 9 0.12% 1 0.97%
jonathan corbet jonathan corbet 6 0.08% 1 0.97%
al viro al viro 2 0.03% 1 0.97%
paul e. mckenney paul e. mckenney 2 0.03% 1 0.97%
harvey harrison harvey harrison 1 0.01% 1 0.97%
paul gortmaker paul gortmaker 1 0.01% 1 0.97%
frederic weisbecker frederic weisbecker 1 0.01% 1 0.97%
Total 7591 100.00% 103 100.00%
Directory: lib

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
	Person	Tokens	Prop	Commits	CommitProp
matthew wilcox	matthew wilcox	29	100.00%	1	100.00%
	Total	29	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.10 lib/radix-tree.c

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