+++ /dev/null
-/*
- * GPL HEADER START
- *
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 only,
- * as published by the Free Software Foundation.
- *
- * 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 version 2 for more details (a copy is included
- * in the LICENSE file that accompanied this code).
- *
- * You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see
- * http://www.gnu.org/licenses/gpl-2.0.html
- *
- * GPL HEADER END
- */
-/*
- * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
- * Use is subject to license terms.
- *
- * Copyright (c) 2014, Intel Corporation.
- */
-/*
- * This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
- *
- * lustre/ldlm/interval_tree.c
- *
- * Interval tree library used by ldlm extent lock code
- *
- * Author: Huang Wei <huangwei@clusterfs.com>
- * Author: Jay Xiong <jinshan.xiong@sun.com>
- */
-
-#include <lustre_dlm.h>
-#include <interval_tree.h>
-
-enum {
- INTERVAL_RED = 0,
- INTERVAL_BLACK = 1
-};
-
-static inline int node_is_left_child(struct interval_node *node)
-{
- LASSERT(node->in_parent != NULL);
- return node == node->in_parent->in_left;
-}
-
-static inline int node_is_right_child(struct interval_node *node)
-{
- LASSERT(node->in_parent != NULL);
- return node == node->in_parent->in_right;
-}
-
-static inline int node_is_red(struct interval_node *node)
-{
- return node->in_color == INTERVAL_RED;
-}
-
-static inline int node_is_black(struct interval_node *node)
-{
- return node->in_color == INTERVAL_BLACK;
-}
-
-static inline int extent_compare(struct interval_node_extent *e1,
- struct interval_node_extent *e2)
-{
- int rc;
-
- if (e1->start == e2->start) {
- if (e1->end < e2->end)
- rc = -1;
- else if (e1->end > e2->end)
- rc = 1;
- else
- rc = 0;
- } else {
- if (e1->start < e2->start)
- rc = -1;
- else
- rc = 1;
- }
- return rc;
-}
-
-static inline int extent_equal(struct interval_node_extent *e1,
- struct interval_node_extent *e2)
-{
- return (e1->start == e2->start) && (e1->end == e2->end);
-}
-
-static inline int extent_overlapped(struct interval_node_extent *e1,
- struct interval_node_extent *e2)
-{
- return (e1->start <= e2->end) && (e2->start <= e1->end);
-}
-
-static inline int node_compare(struct interval_node *n1,
- struct interval_node *n2)
-{
- return extent_compare(&n1->in_extent, &n2->in_extent);
-}
-
-int node_equal(struct interval_node *n1, struct interval_node *n2)
-{
- return extent_equal(&n1->in_extent, &n2->in_extent);
-}
-
-static inline __u64 max_u64(__u64 x, __u64 y)
-{
- return x > y ? x : y;
-}
-
-static inline __u64 min_u64(__u64 x, __u64 y)
-{
- return x < y ? x : y;
-}
-
-#define interval_for_each(node, root) \
-for (node = interval_first(root); node != NULL; \
- node = interval_next(node))
-
-#define interval_for_each_reverse(node, root) \
-for (node = interval_last(root); node != NULL; \
- node = interval_prev(node))
-
-static struct interval_node *interval_first(struct interval_node *node)
-{
- ENTRY;
-
- if (!node)
- RETURN(NULL);
- while (node->in_left)
- node = node->in_left;
- RETURN(node);
-}
-
-static struct interval_node *interval_last(struct interval_node *node)
-{
- ENTRY;
-
- if (!node)
- RETURN(NULL);
- while (node->in_right)
- node = node->in_right;
- RETURN(node);
-}
-
-static struct interval_node *interval_next(struct interval_node *node)
-{
- ENTRY;
-
- if (!node)
- RETURN(NULL);
- if (node->in_right)
- RETURN(interval_first(node->in_right));
- while (node->in_parent && node_is_right_child(node))
- node = node->in_parent;
- RETURN(node->in_parent);
-}
-
-static struct interval_node *interval_prev(struct interval_node *node)
-{
- ENTRY;
-
- if (!node)
- RETURN(NULL);
-
- if (node->in_left)
- RETURN(interval_last(node->in_left));
-
- while (node->in_parent && node_is_left_child(node))
- node = node->in_parent;
-
- RETURN(node->in_parent);
-}
-
-enum interval_iter interval_iterate(struct interval_node *root,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *node;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- ENTRY;
-
- interval_for_each(node, root) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- RETURN(rc);
-}
-EXPORT_SYMBOL(interval_iterate);
-
-enum interval_iter interval_iterate_reverse(struct interval_node *root,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *node;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- ENTRY;
-
- interval_for_each_reverse(node, root) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- RETURN(rc);
-}
-EXPORT_SYMBOL(interval_iterate_reverse);
-
-/* try to find a node with same interval in the tree,
- * if found, return the pointer to the node, otherwise return NULL
- */
-struct interval_node *interval_find(struct interval_node *root,
- struct interval_node_extent *ex)
-{
- struct interval_node *walk = root;
- int rc;
-
- ENTRY;
-
- while (walk) {
- rc = extent_compare(ex, &walk->in_extent);
- if (rc == 0)
- break;
- else if (rc < 0)
- walk = walk->in_left;
- else
- walk = walk->in_right;
- }
-
- RETURN(walk);
-}
-EXPORT_SYMBOL(interval_find);
-
-static void __rotate_change_maxhigh(struct interval_node *node,
- struct interval_node *rotate)
-{
- __u64 left_max, right_max;
-
- rotate->in_max_high = node->in_max_high;
- left_max = node->in_left ? node->in_left->in_max_high : 0;
- right_max = node->in_right ? node->in_right->in_max_high : 0;
- node->in_max_high = max_u64(interval_high(node),
- max_u64(left_max, right_max));
-}
-
-/* The left rotation "pivots" around the link from node to node->right, and
- * - node will be linked to node->right's left child, and
- * - node->right's left child will be linked to node's right child.
- */
-static void __rotate_left(struct interval_node *node,
- struct interval_node **root)
-{
- struct interval_node *right = node->in_right;
- struct interval_node *parent = node->in_parent;
-
- node->in_right = right->in_left;
- if (node->in_right)
- right->in_left->in_parent = node;
-
- right->in_left = node;
- right->in_parent = parent;
- if (parent) {
- if (node_is_left_child(node))
- parent->in_left = right;
- else
- parent->in_right = right;
- } else {
- *root = right;
- }
- node->in_parent = right;
-
- /* update max_high for node and right */
- __rotate_change_maxhigh(node, right);
-}
-
-/* The right rotation "pivots" around the link from node to node->left, and
- * - node will be linked to node->left's right child, and
- * - node->left's right child will be linked to node's left child.
- */
-static void __rotate_right(struct interval_node *node,
- struct interval_node **root)
-{
- struct interval_node *left = node->in_left;
- struct interval_node *parent = node->in_parent;
-
- node->in_left = left->in_right;
- if (node->in_left)
- left->in_right->in_parent = node;
- left->in_right = node;
-
- left->in_parent = parent;
- if (parent) {
- if (node_is_right_child(node))
- parent->in_right = left;
- else
- parent->in_left = left;
- } else {
- *root = left;
- }
- node->in_parent = left;
-
- /* update max_high for node and left */
- __rotate_change_maxhigh(node, left);
-}
-
-#define interval_swap(a, b) do { \
- struct interval_node *c = a; a = b; b = c; \
-} while (0)
-
-/*
- * Operations INSERT and DELETE, when run on a tree with n keys,
- * take O(logN) time.Because they modify the tree, the result
- * may violate the red-black properties.To restore these properties,
- * we must change the colors of some of the nodes in the tree
- * and also change the pointer structure.
- */
-static void interval_insert_color(struct interval_node *node,
- struct interval_node **root)
-{
- struct interval_node *parent, *gparent;
-
- ENTRY;
-
- while ((parent = node->in_parent) && node_is_red(parent)) {
- gparent = parent->in_parent;
- /* Parent is RED, so gparent must not be NULL */
- if (node_is_left_child(parent)) {
- struct interval_node *uncle;
-
- uncle = gparent->in_right;
- if (uncle && node_is_red(uncle)) {
- uncle->in_color = INTERVAL_BLACK;
- parent->in_color = INTERVAL_BLACK;
- gparent->in_color = INTERVAL_RED;
- node = gparent;
- continue;
- }
-
- if (parent->in_right == node) {
- __rotate_left(parent, root);
- interval_swap(node, parent);
- }
-
- parent->in_color = INTERVAL_BLACK;
- gparent->in_color = INTERVAL_RED;
- __rotate_right(gparent, root);
- } else {
- struct interval_node *uncle;
-
- uncle = gparent->in_left;
- if (uncle && node_is_red(uncle)) {
- uncle->in_color = INTERVAL_BLACK;
- parent->in_color = INTERVAL_BLACK;
- gparent->in_color = INTERVAL_RED;
- node = gparent;
- continue;
- }
-
- if (node_is_left_child(node)) {
- __rotate_right(parent, root);
- interval_swap(node, parent);
- }
-
- parent->in_color = INTERVAL_BLACK;
- gparent->in_color = INTERVAL_RED;
- __rotate_left(gparent, root);
- }
- }
-
- (*root)->in_color = INTERVAL_BLACK;
- EXIT;
-}
-
-struct interval_node *interval_insert(struct interval_node *node,
- struct interval_node **root)
-{
- struct interval_node **p, *parent = NULL;
-
- ENTRY;
-
- LASSERT(!interval_is_intree(node));
- p = root;
- while (*p) {
- parent = *p;
- if (node_equal(parent, node))
- RETURN(parent);
-
- /* max_high field must be updated after each iteration */
- if (parent->in_max_high < interval_high(node))
- parent->in_max_high = interval_high(node);
-
- if (node_compare(node, parent) < 0)
- p = &parent->in_left;
- else
- p = &parent->in_right;
- }
-
- /* link node into the tree */
- node->in_parent = parent;
- node->in_color = INTERVAL_RED;
- node->in_left = node->in_right = NULL;
- *p = node;
-
- interval_insert_color(node, root);
- node->in_intree = 1;
-
- RETURN(NULL);
-}
-EXPORT_SYMBOL(interval_insert);
-
-static inline int node_is_black_or_0(struct interval_node *node)
-{
- return !node || node_is_black(node);
-}
-
-static void interval_erase_color(struct interval_node *node,
- struct interval_node *parent,
- struct interval_node **root)
-{
- struct interval_node *tmp;
-
- ENTRY;
-
- while (node_is_black_or_0(node) && node != *root) {
- if (parent->in_left == node) {
- tmp = parent->in_right;
- if (node_is_red(tmp)) {
- tmp->in_color = INTERVAL_BLACK;
- parent->in_color = INTERVAL_RED;
- __rotate_left(parent, root);
- tmp = parent->in_right;
- }
- if (node_is_black_or_0(tmp->in_left) &&
- node_is_black_or_0(tmp->in_right)) {
- tmp->in_color = INTERVAL_RED;
- node = parent;
- parent = node->in_parent;
- } else {
- if (node_is_black_or_0(tmp->in_right)) {
- struct interval_node *o_left;
-
- if ((o_left = tmp->in_left))
- o_left->in_color =
- INTERVAL_BLACK;
- tmp->in_color = INTERVAL_RED;
- __rotate_right(tmp, root);
- tmp = parent->in_right;
- }
- tmp->in_color = parent->in_color;
- parent->in_color = INTERVAL_BLACK;
- if (tmp->in_right)
- tmp->in_right->in_color =
- INTERVAL_BLACK;
- __rotate_left(parent, root);
- node = *root;
- break;
- }
- } else {
- tmp = parent->in_left;
- if (node_is_red(tmp)) {
- tmp->in_color = INTERVAL_BLACK;
- parent->in_color = INTERVAL_RED;
- __rotate_right(parent, root);
- tmp = parent->in_left;
- }
- if (node_is_black_or_0(tmp->in_left) &&
- node_is_black_or_0(tmp->in_right)) {
- tmp->in_color = INTERVAL_RED;
- node = parent;
- parent = node->in_parent;
- } else {
- if (node_is_black_or_0(tmp->in_left)) {
- struct interval_node *o_right;
-
- if ((o_right = tmp->in_right))
- o_right->in_color =
- INTERVAL_BLACK;
- tmp->in_color = INTERVAL_RED;
- __rotate_left(tmp, root);
- tmp = parent->in_left;
- }
- tmp->in_color = parent->in_color;
- parent->in_color = INTERVAL_BLACK;
- if (tmp->in_left)
- tmp->in_left->in_color = INTERVAL_BLACK;
- __rotate_right(parent, root);
- node = *root;
- break;
- }
- }
- }
- if (node)
- node->in_color = INTERVAL_BLACK;
- EXIT;
-}
-
-/*
- * if the @max_high value of @node is changed, this function traverse a path
- * from node up to the root to update max_high for the whole tree.
- */
-static void update_maxhigh(struct interval_node *node,
- __u64 old_maxhigh)
-{
- __u64 left_max, right_max;
-
- ENTRY;
-
- while (node) {
- left_max = node->in_left ? node->in_left->in_max_high : 0;
- right_max = node->in_right ? node->in_right->in_max_high : 0;
- node->in_max_high = max_u64(interval_high(node),
- max_u64(left_max, right_max));
-
- if (node->in_max_high >= old_maxhigh)
- break;
- node = node->in_parent;
- }
- EXIT;
-}
-
-void interval_erase(struct interval_node *node,
- struct interval_node **root)
-{
- struct interval_node *child, *parent;
- int color;
-
- ENTRY;
-
- LASSERT(interval_is_intree(node));
- node->in_intree = 0;
- if (!node->in_left) {
- child = node->in_right;
- } else if (!node->in_right) {
- child = node->in_left;
- } else { /* Both left and right child are not NULL */
- struct interval_node *old = node;
-
- node = interval_next(node);
- child = node->in_right;
- parent = node->in_parent;
- color = node->in_color;
-
- if (child)
- child->in_parent = parent;
- if (parent == old)
- parent->in_right = child;
- else
- parent->in_left = child;
-
- node->in_color = old->in_color;
- node->in_right = old->in_right;
- node->in_left = old->in_left;
- node->in_parent = old->in_parent;
-
- if (old->in_parent) {
- if (node_is_left_child(old))
- old->in_parent->in_left = node;
- else
- old->in_parent->in_right = node;
- } else {
- *root = node;
- }
-
- old->in_left->in_parent = node;
- if (old->in_right)
- old->in_right->in_parent = node;
- update_maxhigh(child ? : parent, node->in_max_high);
- update_maxhigh(node, old->in_max_high);
- if (parent == old)
- parent = node;
- goto color;
- }
- parent = node->in_parent;
- color = node->in_color;
-
- if (child)
- child->in_parent = parent;
- if (parent) {
- if (node_is_left_child(node))
- parent->in_left = child;
- else
- parent->in_right = child;
- } else {
- *root = child;
- }
-
- update_maxhigh(child ? : parent, node->in_max_high);
-
-color:
- if (color == INTERVAL_BLACK)
- interval_erase_color(child, parent, root);
- EXIT;
-}
-EXPORT_SYMBOL(interval_erase);
-
-static inline int interval_may_overlap(struct interval_node *node,
- struct interval_node_extent *ext)
-{
- return (ext->start <= node->in_max_high &&
- ext->end >= interval_low(node));
-}
-
-/*
- * This function finds all intervals that overlap interval ext,
- * and calls func to handle resulted intervals one by one.
- * in lustre, this function will find all conflicting locks in
- * the granted queue and add these locks to the ast work list.
- *
- * {
- * if (node == NULL)
- * return 0;
- * if (ext->end < interval_low(node)) {
- * interval_search(node->in_left, ext, func, data);
- * } else if (interval_may_overlap(node, ext)) {
- * if (extent_overlapped(ext, &node->in_extent))
- * func(node, data);
- * interval_search(node->in_left, ext, func, data);
- * interval_search(node->in_right, ext, func, data);
- * }
- * return 0;
- * }
- *
- */
-enum interval_iter interval_search(struct interval_node *node,
- struct interval_node_extent *ext,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *parent;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- ENTRY;
-
- LASSERT(ext != NULL);
- LASSERT(func != NULL);
-
- while (node) {
- if (ext->end < interval_low(node)) {
- if (node->in_left) {
- node = node->in_left;
- continue;
- }
- } else if (interval_may_overlap(node, ext)) {
- if (extent_overlapped(ext, &node->in_extent)) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- if (node->in_left) {
- node = node->in_left;
- continue;
- }
- if (node->in_right) {
- node = node->in_right;
- continue;
- }
- }
-
- parent = node->in_parent;
- while (parent) {
- if (node_is_left_child(node) &&
- parent->in_right) {
- /* If we ever got the left, it means that the
- * parent met ext->end<interval_low(parent), or
- * may_overlap(parent). If the former is true,
- * we needn't go back. So stop early and check
- * may_overlap(parent) after this loop.
- */
- node = parent->in_right;
- break;
- }
- node = parent;
- parent = parent->in_parent;
- }
- if (parent == NULL || !interval_may_overlap(parent, ext))
- break;
- }
-
- RETURN(rc);
-}
-EXPORT_SYMBOL(interval_search);
-
-static enum interval_iter interval_overlap_cb(struct interval_node *n,
- void *args)
-{
- *(int *)args = 1;
- return INTERVAL_ITER_STOP;
-}
-
-int interval_is_overlapped(struct interval_node *root,
- struct interval_node_extent *ext)
-{
- int has = 0;
- (void)interval_search(root, ext, interval_overlap_cb, &has);
- return has;
-}
-EXPORT_SYMBOL(interval_is_overlapped);
-
-/* Don't expand to low. Expanding downwards is expensive, and meaningless to
- * some extents, because programs seldom do IO backward.
- *
- * The recursive algorithm of expanding low:
- * expand_low {
- * struct interval_node *tmp;
- * static __u64 res = 0;
- *
- * if (root == NULL)
- * return res;
- * if (root->in_max_high < low) {
- * res = max_u64(root->in_max_high + 1, res);
- * return res;
- * } else if (low < interval_low(root)) {
- * interval_expand_low(root->in_left, low);
- * return res;
- * }
- *
- * if (interval_high(root) < low)
- * res = max_u64(interval_high(root) + 1, res);
- * interval_expand_low(root->in_left, low);
- * interval_expand_low(root->in_right, low);
- *
- * return res;
- * }
- *
- * It's much easy to eliminate the recursion, see interval_search for
- * an example. -jay
- */
-static inline __u64 interval_expand_low(struct interval_node *root, __u64 low)
-{
- /* we only concern the empty tree right now. */
- if (root == NULL)
- return 0;
- return low;
-}
-
-static inline __u64 interval_expand_high(struct interval_node *node, __u64 high)
-{
- __u64 result = ~0;
-
- while (node != NULL) {
- if (node->in_max_high < high)
- break;
-
- if (interval_low(node) > high) {
- result = interval_low(node) - 1;
- node = node->in_left;
- } else {
- node = node->in_right;
- }
- }
-
- return result;
-}
-
-/* expanding the extent based on @ext. */
-void interval_expand(struct interval_node *root,
- struct interval_node_extent *ext,
- struct interval_node_extent *limiter)
-{
- /* The assertion of interval_is_overlapped is expensive because we may
- * travel many nodes to find the overlapped node.
- */
- LASSERT(interval_is_overlapped(root, ext) == 0);
- if (!limiter || limiter->start < ext->start)
- ext->start = interval_expand_low(root, ext->start);
- if (!limiter || limiter->end > ext->end)
- ext->end = interval_expand_high(root, ext->end);
- LASSERT(interval_is_overlapped(root, ext) == 0);
-}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff