1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/kernel.h> 37 #include <sys/sysctl.h> 38 39 #include <linux/slab.h> 40 #include <linux/kernel.h> 41 #include <linux/radix-tree.h> 42 #include <linux/err.h> 43 44 static MALLOC_DEFINE(M_RADIX, "radix", "Linux radix compat"); 45 46 static inline int 47 radix_max(struct radix_tree_root *root) 48 { 49 return (1 << (root->height * RADIX_TREE_MAP_SHIFT)) - 1; 50 } 51 52 static inline int 53 radix_pos(long id, int height) 54 { 55 return (id >> (RADIX_TREE_MAP_SHIFT * height)) & RADIX_TREE_MAP_MASK; 56 } 57 58 void * 59 radix_tree_lookup(struct radix_tree_root *root, unsigned long index) 60 { 61 struct radix_tree_node *node; 62 void *item; 63 int height; 64 65 item = NULL; 66 node = root->rnode; 67 height = root->height - 1; 68 if (index > radix_max(root)) 69 goto out; 70 while (height && node) 71 node = node->slots[radix_pos(index, height--)]; 72 if (node) 73 item = node->slots[radix_pos(index, 0)]; 74 75 out: 76 return (item); 77 } 78 79 void * 80 radix_tree_delete(struct radix_tree_root *root, unsigned long index) 81 { 82 struct radix_tree_node *stack[RADIX_TREE_MAX_HEIGHT]; 83 struct radix_tree_node *node; 84 void *item; 85 int height; 86 int idx; 87 88 item = NULL; 89 node = root->rnode; 90 height = root->height - 1; 91 if (index > radix_max(root)) 92 goto out; 93 /* 94 * Find the node and record the path in stack. 95 */ 96 while (height && node) { 97 stack[height] = node; 98 node = node->slots[radix_pos(index, height--)]; 99 } 100 idx = radix_pos(index, 0); 101 if (node) 102 item = node->slots[idx]; 103 /* 104 * If we removed something reduce the height of the tree. 105 */ 106 if (item) 107 for (;;) { 108 node->slots[idx] = NULL; 109 node->count--; 110 if (node->count > 0) 111 break; 112 free(node, M_RADIX); 113 if (node == root->rnode) { 114 root->rnode = NULL; 115 root->height = 0; 116 break; 117 } 118 height++; 119 node = stack[height]; 120 idx = radix_pos(index, height); 121 } 122 out: 123 return (item); 124 } 125 126 int 127 radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item) 128 { 129 struct radix_tree_node *node; 130 struct radix_tree_node *temp[RADIX_TREE_MAX_HEIGHT - 1]; 131 int height; 132 int idx; 133 134 /* bail out upon insertion of a NULL item */ 135 if (item == NULL) 136 return (-EINVAL); 137 138 /* get root node, if any */ 139 node = root->rnode; 140 141 /* allocate root node, if any */ 142 if (node == NULL) { 143 node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO); 144 if (node == NULL) 145 return (-ENOMEM); 146 root->rnode = node; 147 root->height++; 148 } 149 150 /* expand radix tree as needed */ 151 while (radix_max(root) < index) { 152 153 /* check if the radix tree is getting too big */ 154 if (root->height == RADIX_TREE_MAX_HEIGHT) 155 return (-E2BIG); 156 157 /* 158 * If the root radix level is not empty, we need to 159 * allocate a new radix level: 160 */ 161 if (node->count != 0) { 162 node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO); 163 if (node == NULL) 164 return (-ENOMEM); 165 node->slots[0] = root->rnode; 166 node->count++; 167 root->rnode = node; 168 } 169 root->height++; 170 } 171 172 /* get radix tree height index */ 173 height = root->height - 1; 174 175 /* walk down the tree until the first missing node, if any */ 176 for ( ; height != 0; height--) { 177 idx = radix_pos(index, height); 178 if (node->slots[idx] == NULL) 179 break; 180 node = node->slots[idx]; 181 } 182 183 /* allocate the missing radix levels, if any */ 184 for (idx = 0; idx != height; idx++) { 185 temp[idx] = malloc(sizeof(*node), M_RADIX, 186 root->gfp_mask | M_ZERO); 187 if (temp[idx] == NULL) { 188 while(idx--) 189 free(temp[idx], M_RADIX); 190 /* Check if we should free the root node as well. */ 191 if (root->rnode->count == 0) { 192 free(root->rnode, M_RADIX); 193 root->rnode = NULL; 194 root->height = 0; 195 } 196 return (-ENOMEM); 197 } 198 } 199 200 /* setup new radix levels, if any */ 201 for ( ; height != 0; height--) { 202 idx = radix_pos(index, height); 203 node->slots[idx] = temp[height - 1]; 204 node->count++; 205 node = node->slots[idx]; 206 } 207 208 /* 209 * Insert and adjust count if the item does not already exist. 210 */ 211 idx = radix_pos(index, 0); 212 if (node->slots[idx]) 213 return (-EEXIST); 214 node->slots[idx] = item; 215 node->count++; 216 217 return (0); 218 } 219