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LU-12616 obclass: fix MDS start/stop race
[fs/lustre-release.git] / lustre / ldlm / interval_tree.c
index b0e0a9b..1b1bc3a 100644 (file)
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * GPL HEADER START
  *
- *  Interval tree library used by ldlm extent lock code
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- *  Copyright (c) 2007 Cluster File Systems, Inc.
- *   Author: Huang Wei <huangwei@clusterfs.com>
- *   Author: Jay Xiong <jinshan.xiong@sun.com>
+ * 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 file is part of the Lustre file system, http://www.lustre.org
- *   Lustre is a trademark of Cluster File Systems, Inc.
+ * 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 may have signed or agreed to another license before downloading
- *   this software.  If so, you are bound by the terms and conditions
- *   of that agreement, and the following does not apply to you.  See the
- *   LICENSE file included with this distribution for more information.
+ * 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
  *
- *   If you did not agree to a different license, then this copy of Lustre
- *   is open source software; you can redistribute it and/or modify it
- *   under the terms of version 2 of the GNU General Public License as
- *   published by the Free Software Foundation.
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
  *
- *   In either case, Lustre 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
- *   license text for more details.
+ * Copyright (c) 2014, Intel Corporation.
  */
-#ifdef __KERNEL__
-# include <lustre_dlm.h>
-#else
-# include <liblustre.h>
-#endif
-#include <obd_support.h>
+/*
+ * 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
+       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;
+       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;
+       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;
+       return node->in_color == INTERVAL_RED;
 }
 
 static inline int node_is_black(struct interval_node *node)
 {
-        return node->in_color == INTERVAL_BLACK;
+       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;
+                                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)
+                              struct interval_node_extent *e2)
 {
-        return (e1->start == e2->start) && (e1->end == e2->end);
+       return (e1->start == e2->start) && (e1->end == e2->end);
 }
 
-static inline int extent_overlapped(struct interval_node_extent *e1, 
-                                    struct interval_node_extent *e2)
+static inline int extent_overlapped(struct interval_node_extent *e1,
+                                   struct interval_node_extent *e2)
 {
-        return (e1->start <= e2->end) && (e2->start <= e1->end);
+       return (e1->start <= e2->end) && (e2->start <= e1->end);
 }
 
 static inline int node_compare(struct interval_node *n1,
-                               struct interval_node *n2)
+                              struct interval_node *n2)
 {
-        return extent_compare(&n1->in_extent, &n2->in_extent);
+       return extent_compare(&n1->in_extent, &n2->in_extent);
 }
 
-static inline int node_equal(struct interval_node *n1,
-                             struct interval_node *n2)
+int node_equal(struct interval_node *n1, struct interval_node *n2)
 {
-        return extent_equal(&n1->in_extent, &n2->in_extent);
+       return extent_equal(&n1->in_extent, &n2->in_extent);
 }
 
 static inline __u64 max_u64(__u64 x, __u64 y)
 {
-        return x > y ? x : y;
+       return x > y ? x : y;
 }
 
 static inline __u64 min_u64(__u64 x, __u64 y)
 {
-        return x < y ? x : y;
+       return x < y ? x : y;
 }
 
 #define interval_for_each(node, root)                   \
 for (node = interval_first(root); node != NULL;         \
-     node = interval_next(node))
+       node = interval_next(node))
 
 #define interval_for_each_reverse(node, root)           \
 for (node = interval_last(root); node != NULL;          \
-     node = interval_prev(node))
+       node = interval_prev(node))
 
 static struct interval_node *interval_first(struct interval_node *node)
 {
-        ENTRY;
+       ENTRY;
 
-        if (!node)
-                RETURN(NULL);
-        while (node->in_left)
-                node = node->in_left;
-        RETURN(node);
+       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;
+       ENTRY;
 
-        if (!node)
-                RETURN(NULL);
-        while (node->in_right)
-                node = node->in_right;
-        RETURN(node);
+       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;
+       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);
+       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;
+       ENTRY;
 
-        if (!node)
-                RETURN(NULL);
+       if (!node)
+               RETURN(NULL);
 
-        if (node->in_left)
-                RETURN(interval_last(node->in_left));
+       if (node->in_left)
+               RETURN(interval_last(node->in_left));
 
-        while (node->in_parent && node_is_left_child(node))
-                node = node->in_parent;
+       while (node->in_parent && node_is_left_child(node))
+               node = node->in_parent;
 
-        RETURN(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;
-        }
+                                   interval_callback_t func,
+                                   void *data)
+{
+       struct interval_node *node;
+       enum interval_iter rc = INTERVAL_ITER_CONT;
+
+       ENTRY;
 
-        RETURN(rc);
+       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;
-        }
+                                           interval_callback_t func,
+                                           void *data)
+{
+       struct interval_node *node;
+       enum interval_iter rc = INTERVAL_ITER_CONT;
 
-        RETURN(rc);
+       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*/
+ * 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;
-        }
+                                   struct interval_node_extent *ex)
+{
+       struct interval_node *walk = root;
+       int rc;
+
+       ENTRY;
 
-        RETURN(walk);
+       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)
+                                   struct interval_node *rotate)
 {
-        __u64 left_max, right_max;
+       __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));
+       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.  */
+ * - 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;
+                         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);
+       /* 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.  */
+ * - 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;
+                          struct interval_node **root)
+{
+       struct interval_node *left = node->in_left;
+       struct interval_node *parent = node->in_parent;
 
-        /* update max_high for node and left */
-        __rotate_change_maxhigh(node, left);
+       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;      \
+       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 
+ * 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 **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;
+       struct interval_node **p, *parent = NULL;
+
+       ENTRY;
 
-        p = root;
+       LASSERT(!interval_is_intree(node));
+       p = root;
         while (*p) {
                 parent = *p;
                 if (node_equal(parent, node))
@@ -390,198 +407,209 @@ struct interval_node *interval_insert(struct interval_node *node,
                         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;
+       /* 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);
+       interval_insert_color(node, root);
+       node->in_intree = 1;
 
-        RETURN(NULL);
+       RETURN(NULL);
 }
 EXPORT_SYMBOL(interval_insert);
 
 static inline int node_is_black_or_0(struct interval_node *node)
 {
-        return !node || node_is_black(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;
+                                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 
+/*
+ * 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  old_maxhigh)
 {
-        __u64 left_max, right_max;
-        ENTRY;
+       __u64 left_max, right_max;
 
-        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));
+       ENTRY;
 
-                if (node->in_max_high >= old_maxhigh)
-                        break;
-                node = node->in_parent;
-        }
-        EXIT;
+       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;
-
-        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;
-                        parent = node;
-                } 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, node->in_max_high);
-                update_maxhigh(node, old->in_max_high);
-                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, node->in_max_high);
+                   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;
+       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)
+                                      struct interval_node_extent *ext)
 {
-        return (ext->start <= node->in_max_high &&
-                ext->end >= interval_low(node));
+       return (ext->start <= node->in_max_high &&
+               ext->end >= interval_low(node));
 }
 
 /*
@@ -606,75 +634,78 @@ static inline int interval_may_overlap(struct interval_node *node,
  *
  */
 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;
-
-        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;
+                                  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)
+                                             void *args)
 {
-        *(int *)args = 1;
-        return INTERVAL_ITER_STOP;
+       *(int *)args = 1;
+       return INTERVAL_ITER_STOP;
 }
 
 int interval_is_overlapped(struct interval_node *root,
-                           struct interval_node_extent *ext)
+                          struct interval_node_extent *ext)
 {
-        int has = 0;
-        (void)interval_search(root, ext, interval_overlap_cb, &has);
-        return has;
+       int has = 0;
+       (void)interval_search(root, ext, interval_overlap_cb, &has);
+       return has;
 }
 EXPORT_SYMBOL(interval_is_overlapped);
 
@@ -704,48 +735,48 @@ EXPORT_SYMBOL(interval_is_overlapped);
  *        return res;
  * }
  *
- * It's much easy to eliminate the recursion, see interval_search for 
+ * 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;
+       /* 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;
-                }
-        }
+       __u64 result = ~0;
 
-        return result;
+       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);
-}
-EXPORT_SYMBOL(interval_expand);
+                    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);
+}