diff options
Diffstat (limited to 'lib/radix-tree.c')
| -rw-r--r-- | lib/radix-tree.c | 375 |
1 files changed, 287 insertions, 88 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 7bf7d4e60e43..eaea14b8f2ca 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -22,20 +22,21 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#include <linux/bitmap.h> +#include <linux/bitops.h> #include <linux/cpu.h> #include <linux/errno.h> +#include <linux/export.h> +#include <linux/idr.h> #include <linux/init.h> #include <linux/kernel.h> -#include <linux/export.h> -#include <linux/radix-tree.h> +#include <linux/kmemleak.h> #include <linux/percpu.h> +#include <linux/preempt.h> /* in_interrupt() */ +#include <linux/radix-tree.h> +#include <linux/rcupdate.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 */ @@ -60,6 +61,15 @@ static struct kmem_cache *radix_tree_node_cachep; #define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1) /* + * The IDR does not have to be as high as the radix tree since it uses + * signed integers, not unsigned longs. + */ +#define IDR_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(int) - 1) +#define IDR_MAX_PATH (DIV_ROUND_UP(IDR_INDEX_BITS, \ + RADIX_TREE_MAP_SHIFT)) +#define IDR_PRELOAD_SIZE (IDR_MAX_PATH * 2 - 1) + +/* * Per-cpu pool of preloaded nodes */ struct radix_tree_preload { @@ -149,27 +159,32 @@ static inline int tag_get(const struct radix_tree_node *node, unsigned int tag, static inline void root_tag_set(struct radix_tree_root *root, unsigned tag) { - root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT)); + root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT)); } static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag) { - root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT)); + root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT)); } static inline void root_tag_clear_all(struct radix_tree_root *root) { - root->gfp_mask &= __GFP_BITS_MASK; + root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1; } static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag) { - return (__force int)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); + return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT)); } static inline unsigned root_tags_get(const struct radix_tree_root *root) { - return (__force unsigned)root->gfp_mask >> __GFP_BITS_SHIFT; + return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT; +} + +static inline bool is_idr(const struct radix_tree_root *root) +{ + return !!(root->gfp_mask & ROOT_IS_IDR); } /* @@ -187,6 +202,11 @@ static inline int any_tag_set(const struct radix_tree_node *node, return 0; } +static inline void all_tag_set(struct radix_tree_node *node, unsigned int tag) +{ + bitmap_fill(node->tags[tag], RADIX_TREE_MAP_SIZE); +} + /** * radix_tree_find_next_bit - find the next set bit in a memory region * @@ -240,6 +260,13 @@ static inline unsigned long node_maxindex(const struct radix_tree_node *node) return shift_maxindex(node->shift); } +static unsigned long next_index(unsigned long index, + const struct radix_tree_node *node, + unsigned long offset) +{ + return (index & ~node_maxindex(node)) + (offset << node->shift); +} + #ifndef __KERNEL__ static void dump_node(struct radix_tree_node *node, unsigned long index) { @@ -278,11 +305,52 @@ 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); + root->gfp_mask >> ROOT_TAG_SHIFT); if (!radix_tree_is_internal_node(root->rnode)) return; dump_node(entry_to_node(root->rnode), 0); } + +static void dump_ida_node(void *entry, unsigned long index) +{ + unsigned long i; + + if (!entry) + return; + + if (radix_tree_is_internal_node(entry)) { + struct radix_tree_node *node = entry_to_node(entry); + + pr_debug("ida node: %p offset %d indices %lu-%lu parent %p free %lx shift %d count %d\n", + node, node->offset, index * IDA_BITMAP_BITS, + ((index | node_maxindex(node)) + 1) * + IDA_BITMAP_BITS - 1, + node->parent, node->tags[0][0], node->shift, + node->count); + for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) + dump_ida_node(node->slots[i], + index | (i << node->shift)); + } else { + struct ida_bitmap *bitmap = entry; + + pr_debug("ida btmp: %p offset %d indices %lu-%lu data", bitmap, + (int)(index & RADIX_TREE_MAP_MASK), + index * IDA_BITMAP_BITS, + (index + 1) * IDA_BITMAP_BITS - 1); + for (i = 0; i < IDA_BITMAP_LONGS; i++) + pr_cont(" %lx", bitmap->bitmap[i]); + pr_cont("\n"); + } +} + +static void ida_dump(struct ida *ida) +{ + struct radix_tree_root *root = &ida->ida_rt; + pr_debug("ida: %p %p free %d bitmap %p\n", ida, root->rnode, + root->gfp_mask >> ROOT_TAG_SHIFT, + ida->free_bitmap); + dump_ida_node(root->rnode, 0); +} #endif /* @@ -290,13 +358,11 @@ static void radix_tree_dump(struct radix_tree_root *root) * 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, +radix_tree_node_alloc(gfp_t gfp_mask, 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 @@ -533,7 +599,7 @@ static unsigned radix_tree_load_root(const struct radix_tree_root *root, /* * Extend a radix tree so it can store key @index. */ -static int radix_tree_extend(struct radix_tree_root *root, +static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, unsigned long index, unsigned int shift) { struct radix_tree_node *slot; @@ -546,19 +612,27 @@ static int radix_tree_extend(struct radix_tree_root *root, maxshift += RADIX_TREE_MAP_SHIFT; slot = root->rnode; - if (!slot) + if (!slot && (!is_idr(root) || root_tag_get(root, IDR_FREE))) goto out; do { - struct radix_tree_node *node = radix_tree_node_alloc(root, - NULL, shift, 0, 1, 0); + struct radix_tree_node *node = radix_tree_node_alloc(gfp, 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); + if (is_idr(root)) { + all_tag_set(node, IDR_FREE); + if (!root_tag_get(root, IDR_FREE)) { + tag_clear(node, IDR_FREE, 0); + root_tag_set(root, IDR_FREE); + } + } else { + /* Propagate the aggregated tag info to the new child */ + 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); @@ -619,6 +693,8 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root, * one (root->rnode) as far as dependent read barriers go. */ root->rnode = child; + if (is_idr(root) && !tag_get(node, IDR_FREE, 0)) + root_tag_clear(root, IDR_FREE); /* * We have a dilemma here. The node's slot[0] must not be @@ -674,7 +750,12 @@ static bool delete_node(struct radix_tree_root *root, parent->slots[node->offset] = NULL; parent->count--; } else { - root_tag_clear_all(root); + /* + * Shouldn't the tags already have all been cleared + * by the caller? + */ + if (!is_idr(root)) + root_tag_clear_all(root); root->rnode = NULL; } @@ -714,6 +795,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, unsigned long maxindex; unsigned int shift, offset = 0; unsigned long max = index | ((1UL << order) - 1); + gfp_t gfp = root_gfp_mask(root); shift = radix_tree_load_root(root, &child, &maxindex); @@ -721,7 +803,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, if (order > 0 && max == ((1UL << order) - 1)) max++; if (max > maxindex) { - int error = radix_tree_extend(root, max, shift); + int error = radix_tree_extend(root, gfp, max, shift); if (error < 0) return error; shift = error; @@ -732,7 +814,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, shift -= RADIX_TREE_MAP_SHIFT; if (child == NULL) { /* Have to add a child node. */ - child = radix_tree_node_alloc(root, node, shift, + child = radix_tree_node_alloc(gfp, node, shift, offset, 0, 0); if (!child) return -ENOMEM; @@ -755,7 +837,6 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, return 0; } -#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 @@ -791,6 +872,7 @@ static void radix_tree_free_nodes(struct radix_tree_node *node) } } +#ifdef CONFIG_RADIX_TREE_MULTIORDER static inline int insert_entries(struct radix_tree_node *node, void **slot, void *item, unsigned order, bool replace) { @@ -996,69 +1078,70 @@ void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index) } EXPORT_SYMBOL(radix_tree_lookup); -static inline int slot_count(struct radix_tree_node *node, - void **slot) +static inline void replace_sibling_entries(struct radix_tree_node *node, + void **slot, int count, int exceptional) { - int n = 1; #ifdef CONFIG_RADIX_TREE_MULTIORDER void *ptr = node_to_entry(slot); - unsigned offset = get_slot_offset(node, slot); - int i; + unsigned offset = get_slot_offset(node, slot) + 1; - for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { - if (node->slots[offset + i] != ptr) + while (offset < RADIX_TREE_MAP_SIZE) { + if (node->slots[offset] != ptr) break; - n++; + if (count < 0) { + node->slots[offset] = NULL; + node->count--; + } + node->exceptional += exceptional; + offset++; } #endif - return n; } -static void replace_slot(struct radix_tree_root *root, - struct radix_tree_node *node, - void **slot, void *item, - bool warn_typeswitch) +static void replace_slot(void **slot, void *item, struct radix_tree_node *node, + int count, int exceptional) { - 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 (WARN_ON_ONCE(radix_tree_is_internal_node(item))) + return; - if (node) { + if (node && (count || exceptional)) { node->count += count; - if (exceptional) { - exceptional *= slot_count(node, slot); - node->exceptional += exceptional; - } + node->exceptional += exceptional; + replace_sibling_entries(node, slot, count, exceptional); } rcu_assign_pointer(*slot, item); } -static inline void delete_sibling_entries(struct radix_tree_node *node, - void **slot) +static bool node_tag_get(const struct radix_tree_root *root, + const struct radix_tree_node *node, + unsigned int tag, unsigned int offset) { -#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; + if (node) + return tag_get(node, tag, offset); + return root_tag_get(root, tag); +} - 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--; +/* + * IDR users want to be able to store NULL in the tree, so if the slot isn't + * free, don't adjust the count, even if it's transitioning between NULL and + * non-NULL. For the IDA, we mark slots as being IDR_FREE while they still + * have empty bits, but it only stores NULL in slots when they're being + * deleted. + */ +static int calculate_count(struct radix_tree_root *root, + struct radix_tree_node *node, void **slot, + void *item, void *old) +{ + if (is_idr(root)) { + unsigned offset = get_slot_offset(node, slot); + bool free = node_tag_get(root, node, IDR_FREE, offset); + if (!free) + return 0; + if (!old) + return 1; } -#endif + return !!item - !!old; } /** @@ -1078,15 +1161,19 @@ void __radix_tree_replace(struct radix_tree_root *root, void **slot, void *item, radix_tree_update_node_t update_node, void *private) { - if (!item) - delete_sibling_entries(node, slot); + void *old = rcu_dereference_raw(*slot); + int exceptional = !!radix_tree_exceptional_entry(item) - + !!radix_tree_exceptional_entry(old); + int count = calculate_count(root, node, slot, item, old); + /* * 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); + WARN_ON_ONCE(!node && (slot != (void **)&root->rnode) && + (count || exceptional)); + replace_slot(slot, item, node, count, exceptional); if (!node) return; @@ -1116,7 +1203,7 @@ void __radix_tree_replace(struct radix_tree_root *root, void radix_tree_replace_slot(struct radix_tree_root *root, void **slot, void *item) { - replace_slot(root, NULL, slot, item, true); + __radix_tree_replace(root, NULL, slot, item, NULL, NULL); } /** @@ -1191,6 +1278,7 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index, void **slot; unsigned int offset, end; unsigned n, tag, tags = 0; + gfp_t gfp = root_gfp_mask(root); if (!__radix_tree_lookup(root, index, &parent, &slot)) return -ENOENT; @@ -1228,7 +1316,7 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index, for (;;) { if (node->shift > order) { - child = radix_tree_node_alloc(root, node, + child = radix_tree_node_alloc(gfp, node, node->shift - RADIX_TREE_MAP_SHIFT, offset, 0, 0); if (!child) @@ -1444,8 +1532,6 @@ int radix_tree_tag_get(const struct radix_tree_root *root, 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; @@ -1453,8 +1539,6 @@ int radix_tree_tag_get(const struct radix_tree_root *root, 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) @@ -1481,6 +1565,11 @@ static void set_iter_tags(struct radix_tree_iter *iter, unsigned tag_long = offset / BITS_PER_LONG; unsigned tag_bit = offset % BITS_PER_LONG; + if (!node) { + iter->tags = 1; + return; + } + iter->tags = node->tags[tag][tag_long] >> tag_bit; /* This never happens if RADIX_TREE_TAG_LONGS == 1 */ @@ -1873,13 +1962,18 @@ void __radix_tree_delete_node(struct radix_tree_root *root, static bool __radix_tree_delete(struct radix_tree_root *root, struct radix_tree_node *node, void **slot) { + void *old = rcu_dereference_raw(*slot); + int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0; unsigned offset = get_slot_offset(node, slot); int tag; - for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) - node_tag_clear(root, node, tag, offset); + if (is_idr(root)) + node_tag_set(root, node, IDR_FREE, offset); + else + for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) + node_tag_clear(root, node, tag, offset); - replace_slot(root, node, slot, NULL, true); + replace_slot(slot, NULL, node, -1, exceptional); return node && delete_node(root, node, NULL, NULL); } @@ -1916,12 +2010,13 @@ void radix_tree_iter_delete(struct radix_tree_root *root, void *radix_tree_delete_item(struct radix_tree_root *root, unsigned long index, void *item) { - struct radix_tree_node *node; + struct radix_tree_node *node = NULL; void **slot; void *entry; entry = __radix_tree_lookup(root, index, &node, &slot); - if (!entry) + if (!entry && (!is_idr(root) || node_tag_get(root, node, IDR_FREE, + get_slot_offset(node, slot)))) return NULL; if (item && entry != item) @@ -1957,8 +2052,7 @@ void radix_tree_clear_tags(struct radix_tree_root *root, 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; + root_tag_clear_all(root); } } @@ -1973,6 +2067,111 @@ int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag) } EXPORT_SYMBOL(radix_tree_tagged); +/** + * idr_preload - preload for idr_alloc() + * @gfp_mask: allocation mask to use for preloading + * + * Preallocate memory to use for the next call to idr_alloc(). This function + * returns with preemption disabled. It will be enabled by idr_preload_end(). + */ +void idr_preload(gfp_t gfp_mask) +{ + __radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE); +} +EXPORT_SYMBOL(idr_preload); + +void **idr_get_free(struct radix_tree_root *root, + struct radix_tree_iter *iter, gfp_t gfp, int end) +{ + struct radix_tree_node *node = NULL, *child; + void **slot = (void **)&root->rnode; + unsigned long maxindex, start = iter->next_index; + unsigned long max = end > 0 ? end - 1 : INT_MAX; + unsigned int shift, offset = 0; + + grow: + shift = radix_tree_load_root(root, &child, &maxindex); + if (!radix_tree_tagged(root, IDR_FREE)) + start = max(start, maxindex + 1); + if (start > max) + return ERR_PTR(-ENOSPC); + + if (start > maxindex) { + int error = radix_tree_extend(root, gfp, start, shift); + if (error < 0) + return ERR_PTR(error); + shift = error; + child = rcu_dereference_raw(root->rnode); + } + + while (shift) { + shift -= RADIX_TREE_MAP_SHIFT; + if (child == NULL) { + /* Have to add a child node. */ + child = radix_tree_node_alloc(gfp, node, shift, offset, + 0, 0); + if (!child) + return ERR_PTR(-ENOMEM); + all_tag_set(child, IDR_FREE); + rcu_assign_pointer(*slot, node_to_entry(child)); + if (node) + node->count++; + } else if (!radix_tree_is_internal_node(child)) + break; + + node = entry_to_node(child); + offset = radix_tree_descend(node, &child, start); + if (!tag_get(node, IDR_FREE, offset)) { + offset = radix_tree_find_next_bit(node, IDR_FREE, + offset + 1); + start = next_index(start, node, offset); + if (start > max) + return ERR_PTR(-ENOSPC); + while (offset == RADIX_TREE_MAP_SIZE) { + offset = node->offset + 1; + node = node->parent; + if (!node) + goto grow; + shift = node->shift; + } + child = rcu_dereference_raw(node->slots[offset]); + } + slot = &node->slots[offset]; + } + + iter->index = start; + if (node) + iter->next_index = 1 + min(max, (start | node_maxindex(node))); + else + iter->next_index = 1; + iter->node = node; + __set_iter_shift(iter, shift); + set_iter_tags(iter, node, offset, IDR_FREE); + + return slot; +} + +/** + * idr_destroy - release all internal memory from an IDR + * @idr: idr handle + * + * After this function is called, the IDR is empty, and may be reused or + * the data structure containing it may be freed. + * + * A typical clean-up sequence for objects stored in an idr tree will use + * idr_for_each() to free all objects, if necessary, then idr_destroy() to + * free the memory used to keep track of those objects. + */ +void idr_destroy(struct idr *idr) +{ + struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode); + if (radix_tree_is_internal_node(node)) + radix_tree_free_nodes(node); + idr->idr_rt.rnode = NULL; + root_tag_set(&idr->idr_rt, IDR_FREE); +} +EXPORT_SYMBOL(idr_destroy); + static void radix_tree_node_ctor(void *arg) { |