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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-01 07:29:41 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-01 07:29:41 +0300
commitcf393195c3ba5d4c0a8e237eb00f7ef104876ee5 (patch)
tree8aa515ca0e0c00bffbc8dccb9d36ea319f251a12 /include
parent5ecc5ac215bc4d88243a2f4909e70ccc1bda710f (diff)
parentc6ce3e2fe3dacda5e8afb0036c814ae9c3fee9b9 (diff)
downloadlinux-cf393195c3ba5d4c0a8e237eb00f7ef104876ee5.tar.xz
Merge branch 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax
Pull IDR rewrite from Matthew Wilcox: "The most significant part of the following is the patch to rewrite the IDR & IDA to be clients of the radix tree. But there's much more, including an enhancement of the IDA to be significantly more space efficient, an IDR & IDA test suite, some improvements to the IDR API (and driver changes to take advantage of those improvements), several improvements to the radix tree test suite and RCU annotations. The IDR & IDA rewrite had a good spin in linux-next and Andrew's tree for most of the last cycle. Coupled with the IDR test suite, I feel pretty confident that any remaining bugs are quite hard to hit. 0-day did a great job of watching my git tree and pointing out problems; as it hit them, I added new test-cases to be sure not to be caught the same way twice" Willy goes on to expand a bit on the IDR rewrite rationale: "The radix tree and the IDR use very similar data structures. Merging the two codebases lets us share the memory allocation pools, and results in a net deletion of 500 lines of code. It also opens up the possibility of exposing more of the features of the radix tree to users of the IDR (and I have some interesting patches along those lines waiting for 4.12) It also shrinks the size of the 'struct idr' from 40 bytes to 24 which will shrink a fair few data structures that embed an IDR" * 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax: (32 commits) radix tree test suite: Add config option for map shift idr: Add missing __rcu annotations radix-tree: Fix __rcu annotations radix-tree: Add rcu_dereference and rcu_assign_pointer calls radix tree test suite: Run iteration tests for longer radix tree test suite: Fix split/join memory leaks radix tree test suite: Fix leaks in regression2.c radix tree test suite: Fix leaky tests radix tree test suite: Enable address sanitizer radix_tree_iter_resume: Fix out of bounds error radix-tree: Store a pointer to the root in each node radix-tree: Chain preallocated nodes through ->parent radix tree test suite: Dial down verbosity with -v radix tree test suite: Introduce kmalloc_verbose idr: Return the deleted entry from idr_remove radix tree test suite: Build separate binaries for some tests ida: Use exceptional entries for small IDAs ida: Move ida_bitmap to a percpu variable Reimplement IDR and IDA using the radix tree radix-tree: Add radix_tree_iter_delete ...
Diffstat (limited to 'include')
-rw-r--r--include/linux/idr.h148
-rw-r--r--include/linux/radix-tree.h179
2 files changed, 179 insertions, 148 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 3c01b89aed67..bf70b3ef0a07 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -12,47 +12,29 @@
#ifndef __IDR_H__
#define __IDR_H__
-#include <linux/types.h>
-#include <linux/bitops.h>
-#include <linux/init.h>
-#include <linux/rcupdate.h>
+#include <linux/radix-tree.h>
+#include <linux/gfp.h>
+#include <linux/percpu.h>
+
+struct idr {
+ struct radix_tree_root idr_rt;
+ unsigned int idr_next;
+};
/*
- * Using 6 bits at each layer allows us to allocate 7 layers out of each page.
- * 8 bits only gave us 3 layers out of every pair of pages, which is less
- * efficient except for trees with a largest element between 192-255 inclusive.
+ * The IDR API does not expose the tagging functionality of the radix tree
+ * to users. Use tag 0 to track whether a node has free space below it.
*/
-#define IDR_BITS 6
-#define IDR_SIZE (1 << IDR_BITS)
-#define IDR_MASK ((1 << IDR_BITS)-1)
-
-struct idr_layer {
- int prefix; /* the ID prefix of this idr_layer */
- int layer; /* distance from leaf */
- struct idr_layer __rcu *ary[1<<IDR_BITS];
- int count; /* When zero, we can release it */
- union {
- /* A zero bit means "space here" */
- DECLARE_BITMAP(bitmap, IDR_SIZE);
- struct rcu_head rcu_head;
- };
-};
+#define IDR_FREE 0
-struct idr {
- struct idr_layer __rcu *hint; /* the last layer allocated from */
- struct idr_layer __rcu *top;
- int layers; /* only valid w/o concurrent changes */
- int cur; /* current pos for cyclic allocation */
- spinlock_t lock;
- int id_free_cnt;
- struct idr_layer *id_free;
-};
+/* Set the IDR flag and the IDR_FREE tag */
+#define IDR_RT_MARKER ((__force gfp_t)(3 << __GFP_BITS_SHIFT))
-#define IDR_INIT(name) \
+#define IDR_INIT \
{ \
- .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
+ .idr_rt = RADIX_TREE_INIT(IDR_RT_MARKER) \
}
-#define DEFINE_IDR(name) struct idr name = IDR_INIT(name)
+#define DEFINE_IDR(name) struct idr name = IDR_INIT
/**
* idr_get_cursor - Return the current position of the cyclic allocator
@@ -62,9 +44,9 @@ struct idr {
* idr_alloc_cyclic() if it is free (otherwise the search will start from
* this position).
*/
-static inline unsigned int idr_get_cursor(struct idr *idr)
+static inline unsigned int idr_get_cursor(const struct idr *idr)
{
- return READ_ONCE(idr->cur);
+ return READ_ONCE(idr->idr_next);
}
/**
@@ -77,7 +59,7 @@ static inline unsigned int idr_get_cursor(struct idr *idr)
*/
static inline void idr_set_cursor(struct idr *idr, unsigned int val)
{
- WRITE_ONCE(idr->cur, val);
+ WRITE_ONCE(idr->idr_next, val);
}
/**
@@ -97,22 +79,31 @@ static inline void idr_set_cursor(struct idr *idr, unsigned int val)
* period).
*/
-/*
- * This is what we export.
- */
-
-void *idr_find_slowpath(struct idr *idp, int id);
void idr_preload(gfp_t gfp_mask);
-int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t gfp_mask);
-int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask);
-int idr_for_each(struct idr *idp,
+int idr_alloc(struct idr *, void *entry, int start, int end, gfp_t);
+int idr_alloc_cyclic(struct idr *, void *entry, int start, int end, gfp_t);
+int idr_for_each(const struct idr *,
int (*fn)(int id, void *p, void *data), void *data);
-void *idr_get_next(struct idr *idp, int *nextid);
-void *idr_replace(struct idr *idp, void *ptr, int id);
-void idr_remove(struct idr *idp, int id);
-void idr_destroy(struct idr *idp);
-void idr_init(struct idr *idp);
-bool idr_is_empty(struct idr *idp);
+void *idr_get_next(struct idr *, int *nextid);
+void *idr_replace(struct idr *, void *, int id);
+void idr_destroy(struct idr *);
+
+static inline void *idr_remove(struct idr *idr, int id)
+{
+ return radix_tree_delete_item(&idr->idr_rt, id, NULL);
+}
+
+static inline void idr_init(struct idr *idr)
+{
+ INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER);
+ idr->idr_next = 0;
+}
+
+static inline bool idr_is_empty(const struct idr *idr)
+{
+ return radix_tree_empty(&idr->idr_rt) &&
+ radix_tree_tagged(&idr->idr_rt, IDR_FREE);
+}
/**
* idr_preload_end - end preload section started with idr_preload()
@@ -137,19 +128,14 @@ static inline void idr_preload_end(void)
* This function can be called under rcu_read_lock(), given that the leaf
* pointers lifetimes are correctly managed.
*/
-static inline void *idr_find(struct idr *idr, int id)
+static inline void *idr_find(const struct idr *idr, int id)
{
- struct idr_layer *hint = rcu_dereference_raw(idr->hint);
-
- if (hint && (id & ~IDR_MASK) == hint->prefix)
- return rcu_dereference_raw(hint->ary[id & IDR_MASK]);
-
- return idr_find_slowpath(idr, id);
+ return radix_tree_lookup(&idr->idr_rt, id);
}
/**
* idr_for_each_entry - iterate over an idr's elements of a given type
- * @idp: idr handle
+ * @idr: idr handle
* @entry: the type * to use as cursor
* @id: id entry's key
*
@@ -157,57 +143,60 @@ static inline void *idr_find(struct idr *idr, int id)
* after normal terminatinon @entry is left with the value NULL. This
* is convenient for a "not found" value.
*/
-#define idr_for_each_entry(idp, entry, id) \
- for (id = 0; ((entry) = idr_get_next(idp, &(id))) != NULL; ++id)
+#define idr_for_each_entry(idr, entry, id) \
+ for (id = 0; ((entry) = idr_get_next(idr, &(id))) != NULL; ++id)
/**
- * idr_for_each_entry - continue iteration over an idr's elements of a given type
- * @idp: idr handle
+ * idr_for_each_entry_continue - continue iteration over an idr's elements of a given type
+ * @idr: idr handle
* @entry: the type * to use as cursor
* @id: id entry's key
*
* Continue to iterate over list of given type, continuing after
* the current position.
*/
-#define idr_for_each_entry_continue(idp, entry, id) \
- for ((entry) = idr_get_next((idp), &(id)); \
+#define idr_for_each_entry_continue(idr, entry, id) \
+ for ((entry) = idr_get_next((idr), &(id)); \
entry; \
- ++id, (entry) = idr_get_next((idp), &(id)))
+ ++id, (entry) = idr_get_next((idr), &(id)))
/*
* IDA - IDR based id allocator, use when translation from id to
* pointer isn't necessary.
- *
- * IDA_BITMAP_LONGS is calculated to be one less to accommodate
- * ida_bitmap->nr_busy so that the whole struct fits in 128 bytes.
*/
#define IDA_CHUNK_SIZE 128 /* 128 bytes per chunk */
-#define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long) - 1)
+#define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long))
#define IDA_BITMAP_BITS (IDA_BITMAP_LONGS * sizeof(long) * 8)
struct ida_bitmap {
- long nr_busy;
unsigned long bitmap[IDA_BITMAP_LONGS];
};
+DECLARE_PER_CPU(struct ida_bitmap *, ida_bitmap);
+
struct ida {
- struct idr idr;
- struct ida_bitmap *free_bitmap;
+ struct radix_tree_root ida_rt;
};
-#define IDA_INIT(name) { .idr = IDR_INIT((name).idr), .free_bitmap = NULL, }
-#define DEFINE_IDA(name) struct ida name = IDA_INIT(name)
+#define IDA_INIT { \
+ .ida_rt = RADIX_TREE_INIT(IDR_RT_MARKER | GFP_NOWAIT), \
+}
+#define DEFINE_IDA(name) struct ida name = IDA_INIT
int ida_pre_get(struct ida *ida, gfp_t gfp_mask);
int ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
void ida_remove(struct ida *ida, int id);
void ida_destroy(struct ida *ida);
-void ida_init(struct ida *ida);
int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
gfp_t gfp_mask);
void ida_simple_remove(struct ida *ida, unsigned int id);
+static inline void ida_init(struct ida *ida)
+{
+ INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT);
+}
+
/**
* ida_get_new - allocate new ID
* @ida: idr handle
@@ -220,11 +209,8 @@ static inline int ida_get_new(struct ida *ida, int *p_id)
return ida_get_new_above(ida, 0, p_id);
}
-static inline bool ida_is_empty(struct ida *ida)
+static inline bool ida_is_empty(const struct ida *ida)
{
- return idr_is_empty(&ida->idr);
+ return radix_tree_empty(&ida->ida_rt);
}
-
-void __init idr_init_cache(void);
-
#endif /* __IDR_H__ */
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 52bda854593b..3e5735064b71 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -22,11 +22,13 @@
#define _LINUX_RADIX_TREE_H
#include <linux/bitops.h>
-#include <linux/preempt.h>
-#include <linux/types.h>
#include <linux/bug.h>
#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/preempt.h>
#include <linux/rcupdate.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
/*
* The bottom two bits of the slot determine how the remaining bits in the
@@ -94,7 +96,7 @@ struct radix_tree_node {
unsigned char count; /* Total entry count */
unsigned char exceptional; /* Exceptional entry count */
struct radix_tree_node *parent; /* Used when ascending tree */
- void *private_data; /* For tree user */
+ struct radix_tree_root *root; /* The tree we belong to */
union {
struct list_head private_list; /* For tree user */
struct rcu_head rcu_head; /* Used when freeing node */
@@ -103,7 +105,10 @@ struct radix_tree_node {
unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
};
-/* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */
+/* The top bits of gfp_mask are used to store the root tags and the IDR flag */
+#define ROOT_IS_IDR ((__force gfp_t)(1 << __GFP_BITS_SHIFT))
+#define ROOT_TAG_SHIFT (__GFP_BITS_SHIFT + 1)
+
struct radix_tree_root {
gfp_t gfp_mask;
struct radix_tree_node __rcu *rnode;
@@ -123,7 +128,7 @@ do { \
(root)->rnode = NULL; \
} while (0)
-static inline bool radix_tree_empty(struct radix_tree_root *root)
+static inline bool radix_tree_empty(const struct radix_tree_root *root)
{
return root->rnode == NULL;
}
@@ -216,10 +221,8 @@ static inline unsigned int iter_shift(const struct radix_tree_iter *iter)
*/
/**
- * radix_tree_deref_slot - dereference a slot
- * @pslot: pointer to slot, returned by radix_tree_lookup_slot
- * Returns: item that was stored in that slot with any direct pointer flag
- * removed.
+ * radix_tree_deref_slot - dereference a slot
+ * @slot: slot pointer, returned by radix_tree_lookup_slot
*
* For use with radix_tree_lookup_slot(). Caller must hold tree at least read
* locked across slot lookup and dereference. Not required if write lock is
@@ -227,26 +230,27 @@ static inline unsigned int iter_shift(const struct radix_tree_iter *iter)
*
* radix_tree_deref_retry must be used to confirm validity of the pointer if
* only the read lock is held.
+ *
+ * Return: entry stored in that slot.
*/
-static inline void *radix_tree_deref_slot(void **pslot)
+static inline void *radix_tree_deref_slot(void __rcu **slot)
{
- return rcu_dereference(*pslot);
+ return rcu_dereference(*slot);
}
/**
- * radix_tree_deref_slot_protected - dereference a slot without RCU lock but with tree lock held
- * @pslot: pointer to slot, returned by radix_tree_lookup_slot
- * Returns: item that was stored in that slot with any direct pointer flag
- * removed.
- *
- * Similar to radix_tree_deref_slot but only used during migration when a pages
- * mapping is being moved. The caller does not hold the RCU read lock but it
- * must hold the tree lock to prevent parallel updates.
+ * radix_tree_deref_slot_protected - dereference a slot with tree lock held
+ * @slot: slot pointer, returned by radix_tree_lookup_slot
+ *
+ * Similar to radix_tree_deref_slot. The caller does not hold the RCU read
+ * lock but it must hold the tree lock to prevent parallel updates.
+ *
+ * Return: entry stored in that slot.
*/
-static inline void *radix_tree_deref_slot_protected(void **pslot,
+static inline void *radix_tree_deref_slot_protected(void __rcu **slot,
spinlock_t *treelock)
{
- return rcu_dereference_protected(*pslot, lockdep_is_held(treelock));
+ return rcu_dereference_protected(*slot, lockdep_is_held(treelock));
}
/**
@@ -282,9 +286,9 @@ static inline int radix_tree_exception(void *arg)
return unlikely((unsigned long)arg & RADIX_TREE_ENTRY_MASK);
}
-int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
+int __radix_tree_create(struct radix_tree_root *, unsigned long index,
unsigned order, struct radix_tree_node **nodep,
- void ***slotp);
+ void __rcu ***slotp);
int __radix_tree_insert(struct radix_tree_root *, unsigned long index,
unsigned order, void *);
static inline int radix_tree_insert(struct radix_tree_root *root,
@@ -292,55 +296,56 @@ static inline int radix_tree_insert(struct radix_tree_root *root,
{
return __radix_tree_insert(root, index, 0, entry);
}
-void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,
- struct radix_tree_node **nodep, void ***slotp);
-void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
-void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
+void *__radix_tree_lookup(const struct radix_tree_root *, unsigned long index,
+ struct radix_tree_node **nodep, void __rcu ***slotp);
+void *radix_tree_lookup(const struct radix_tree_root *, unsigned long);
+void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *,
+ unsigned long index);
typedef void (*radix_tree_update_node_t)(struct radix_tree_node *, void *);
-void __radix_tree_replace(struct radix_tree_root *root,
- struct radix_tree_node *node,
- void **slot, void *item,
+void __radix_tree_replace(struct radix_tree_root *, struct radix_tree_node *,
+ void __rcu **slot, void *entry,
radix_tree_update_node_t update_node, void *private);
void radix_tree_iter_replace(struct radix_tree_root *,
- const struct radix_tree_iter *, void **slot, void *item);
-void radix_tree_replace_slot(struct radix_tree_root *root,
- void **slot, void *item);
-void __radix_tree_delete_node(struct radix_tree_root *root,
- struct radix_tree_node *node,
+ const struct radix_tree_iter *, void __rcu **slot, void *entry);
+void radix_tree_replace_slot(struct radix_tree_root *,
+ void __rcu **slot, void *entry);
+void __radix_tree_delete_node(struct radix_tree_root *,
+ struct radix_tree_node *,
radix_tree_update_node_t update_node,
void *private);
+void radix_tree_iter_delete(struct radix_tree_root *,
+ struct radix_tree_iter *iter, void __rcu **slot);
void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *);
void *radix_tree_delete(struct radix_tree_root *, unsigned long);
-void radix_tree_clear_tags(struct radix_tree_root *root,
- struct radix_tree_node *node,
- void **slot);
-unsigned int radix_tree_gang_lookup(struct radix_tree_root *root,
+void radix_tree_clear_tags(struct radix_tree_root *, struct radix_tree_node *,
+ void __rcu **slot);
+unsigned int radix_tree_gang_lookup(const struct radix_tree_root *,
void **results, unsigned long first_index,
unsigned int max_items);
-unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root,
- void ***results, unsigned long *indices,
+unsigned int radix_tree_gang_lookup_slot(const struct radix_tree_root *,
+ void __rcu ***results, unsigned long *indices,
unsigned long first_index, unsigned int max_items);
int radix_tree_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order);
void radix_tree_init(void);
-void *radix_tree_tag_set(struct radix_tree_root *root,
+void *radix_tree_tag_set(struct radix_tree_root *,
unsigned long index, unsigned int tag);
-void *radix_tree_tag_clear(struct radix_tree_root *root,
+void *radix_tree_tag_clear(struct radix_tree_root *,
unsigned long index, unsigned int tag);
-int radix_tree_tag_get(struct radix_tree_root *root,
+int radix_tree_tag_get(const struct radix_tree_root *,
unsigned long index, unsigned int tag);
-void radix_tree_iter_tag_set(struct radix_tree_root *root,
+void radix_tree_iter_tag_set(struct radix_tree_root *,
+ const struct radix_tree_iter *iter, unsigned int tag);
+void radix_tree_iter_tag_clear(struct radix_tree_root *,
const struct radix_tree_iter *iter, unsigned int tag);
-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);
-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);
-int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
+unsigned int radix_tree_gang_lookup_tag(const struct radix_tree_root *,
+ void **results, unsigned long first_index,
+ unsigned int max_items, unsigned int tag);
+unsigned int radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *,
+ void __rcu ***results, unsigned long first_index,
+ unsigned int max_items, unsigned int tag);
+int radix_tree_tagged(const struct radix_tree_root *, unsigned int tag);
static inline void radix_tree_preload_end(void)
{
@@ -352,10 +357,14 @@ int radix_tree_split(struct radix_tree_root *, unsigned long index,
unsigned new_order);
int radix_tree_join(struct radix_tree_root *, unsigned long index,
unsigned new_order, void *);
+void __rcu **idr_get_free(struct radix_tree_root *, struct radix_tree_iter *,
+ gfp_t, int end);
-#define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */
-#define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */
-#define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */
+enum {
+ RADIX_TREE_ITER_TAG_MASK = 0x0f, /* tag index in lower nybble */
+ RADIX_TREE_ITER_TAGGED = 0x10, /* lookup tagged slots */
+ RADIX_TREE_ITER_CONTIG = 0x20, /* stop at first hole */
+};
/**
* radix_tree_iter_init - initialize radix tree iterator
@@ -364,7 +373,7 @@ int radix_tree_join(struct radix_tree_root *, unsigned long index,
* @start: iteration starting index
* Returns: NULL
*/
-static __always_inline void **
+static __always_inline void __rcu **
radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
{
/*
@@ -393,10 +402,46 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
* Also it fills @iter with data about chunk: position in the tree (index),
* its end (next_index), and constructs a bit mask for tagged iterating (tags).
*/
-void **radix_tree_next_chunk(struct radix_tree_root *root,
+void __rcu **radix_tree_next_chunk(const struct radix_tree_root *,
struct radix_tree_iter *iter, unsigned flags);
/**
+ * radix_tree_iter_lookup - look up an index in the radix tree
+ * @root: radix tree root
+ * @iter: iterator state
+ * @index: key to look up
+ *
+ * If @index is present in the radix tree, this function returns the slot
+ * containing it and updates @iter to describe the entry. If @index is not
+ * present, it returns NULL.
+ */
+static inline void __rcu **
+radix_tree_iter_lookup(const struct radix_tree_root *root,
+ struct radix_tree_iter *iter, unsigned long index)
+{
+ radix_tree_iter_init(iter, index);
+ return radix_tree_next_chunk(root, iter, RADIX_TREE_ITER_CONTIG);
+}
+
+/**
+ * radix_tree_iter_find - find a present entry
+ * @root: radix tree root
+ * @iter: iterator state
+ * @index: start location
+ *
+ * This function returns the slot containing the entry with the lowest index
+ * which is at least @index. If @index is larger than any present entry, this
+ * function returns NULL. The @iter is updated to describe the entry found.
+ */
+static inline void __rcu **
+radix_tree_iter_find(const struct radix_tree_root *root,
+ struct radix_tree_iter *iter, unsigned long index)
+{
+ radix_tree_iter_init(iter, index);
+ return radix_tree_next_chunk(root, iter, 0);
+}
+
+/**
* radix_tree_iter_retry - retry this chunk of the iteration
* @iter: iterator state
*
@@ -406,7 +451,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
* and continue the iteration.
*/
static inline __must_check
-void **radix_tree_iter_retry(struct radix_tree_iter *iter)
+void __rcu **radix_tree_iter_retry(struct radix_tree_iter *iter)
{
iter->next_index = iter->index;
iter->tags = 0;
@@ -429,7 +474,7 @@ __radix_tree_iter_add(struct radix_tree_iter *iter, unsigned long slots)
* have been invalidated by an insertion or deletion. Call this function
* before releasing the lock to continue the iteration from the next index.
*/
-void **__must_check radix_tree_iter_resume(void **slot,
+void __rcu **__must_check radix_tree_iter_resume(void __rcu **slot,
struct radix_tree_iter *iter);
/**
@@ -445,11 +490,11 @@ radix_tree_chunk_size(struct radix_tree_iter *iter)
}
#ifdef CONFIG_RADIX_TREE_MULTIORDER
-void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
- unsigned flags);
+void __rcu **__radix_tree_next_slot(void __rcu **slot,
+ struct radix_tree_iter *iter, unsigned flags);
#else
/* Can't happen without sibling entries, but the compiler can't tell that */
-static inline void ** __radix_tree_next_slot(void **slot,
+static inline void __rcu **__radix_tree_next_slot(void __rcu **slot,
struct radix_tree_iter *iter, unsigned flags)
{
return slot;
@@ -475,8 +520,8 @@ static inline void ** __radix_tree_next_slot(void **slot,
* b) we are doing non-tagged iteration, and iter->index and iter->next_index
* have been set up so that radix_tree_chunk_size() returns 1 or 0.
*/
-static __always_inline void **
-radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
+static __always_inline void __rcu **radix_tree_next_slot(void __rcu **slot,
+ struct radix_tree_iter *iter, unsigned flags)
{
if (flags & RADIX_TREE_ITER_TAGGED) {
iter->tags >>= 1;
@@ -514,7 +559,7 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
return NULL;
found:
- if (unlikely(radix_tree_is_internal_node(*slot)))
+ if (unlikely(radix_tree_is_internal_node(rcu_dereference_raw(*slot))))
return __radix_tree_next_slot(slot, iter, flags);
return slot;
}