diff options
Diffstat (limited to 'kernel-lib')
| -rw-r--r-- | kernel-lib/crc32c.c | 222 | ||||
| -rw-r--r-- | kernel-lib/crc32c.h | 33 | ||||
| -rw-r--r-- | kernel-lib/interval_tree_generic.h | 193 | ||||
| -rw-r--r-- | kernel-lib/list.h | 486 | ||||
| -rw-r--r-- | kernel-lib/list_sort.c | 144 | ||||
| -rw-r--r-- | kernel-lib/list_sort.h | 14 | ||||
| -rw-r--r-- | kernel-lib/radix-tree.c | 849 | ||||
| -rw-r--r-- | kernel-lib/radix-tree.h | 97 | ||||
| -rw-r--r-- | kernel-lib/rbtree.c | 548 | ||||
| -rw-r--r-- | kernel-lib/rbtree.h | 118 | ||||
| -rw-r--r-- | kernel-lib/rbtree_augmented.h | 249 |
11 files changed, 2953 insertions, 0 deletions
diff --git a/kernel-lib/crc32c.c b/kernel-lib/crc32c.c new file mode 100644 index 00000000..dfa4e6c1 --- /dev/null +++ b/kernel-lib/crc32c.c @@ -0,0 +1,222 @@ +/* + * Copied from the kernel source code, lib/libcrc32c.c. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ +#include "kerncompat.h" +#include "crc32c.h" +#include <inttypes.h> +#include <string.h> +#include <unistd.h> +#include <stdlib.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/wait.h> + +u32 __crc32c_le(u32 crc, unsigned char const *data, size_t length); +static u32 (*crc_function)(u32 crc, unsigned char const *data, size_t length) = __crc32c_le; + +#ifdef __x86_64__ + +/* + * Based on a posting to lkml by Austin Zhang <austin.zhang@intel.com> + * + * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal. + * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE) + * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at: + * http://www.intel.com/products/processor/manuals/ + * Intel(R) 64 and IA-32 Architectures Software Developer's Manual + * Volume 2A: Instruction Set Reference, A-M + */ +#if __SIZEOF_LONG__ == 8 +#define REX_PRE "0x48, " +#define SCALE_F 8 +#else +#define REX_PRE +#define SCALE_F 4 +#endif + +static int crc32c_probed = 0; +static int crc32c_intel_available = 0; + +static uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data, + unsigned long length) +{ + while (length--) { + __asm__ __volatile__( + ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1" + :"=S"(crc) + :"0"(crc), "c"(*data) + ); + data++; + } + + return crc; +} + +/* + * Steps through buffer one byte at at time, calculates reflected + * crc using table. + */ +static uint32_t crc32c_intel(u32 crc, unsigned char const *data, unsigned long length) +{ + unsigned int iquotient = length / SCALE_F; + unsigned int iremainder = length % SCALE_F; + unsigned long *ptmp = (unsigned long *)data; + + while (iquotient--) { + __asm__ __volatile__( + ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;" + :"=S"(crc) + :"0"(crc), "c"(*ptmp) + ); + ptmp++; + } + + if (iremainder) + crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp, + iremainder); + + return crc; +} + +static void do_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx, + unsigned int *edx) +{ + int id = *eax; + + asm("movl %4, %%eax;" + "cpuid;" + "movl %%eax, %0;" + "movl %%ebx, %1;" + "movl %%ecx, %2;" + "movl %%edx, %3;" + : "=r" (*eax), "=r" (*ebx), "=r" (*ecx), "=r" (*edx) + : "r" (id) + : "eax", "ebx", "ecx", "edx"); +} + +static void crc32c_intel_probe(void) +{ + if (!crc32c_probed) { + unsigned int eax, ebx, ecx, edx; + + eax = 1; + + do_cpuid(&eax, &ebx, &ecx, &edx); + crc32c_intel_available = (ecx & (1 << 20)) != 0; + crc32c_probed = 1; + } +} + +void crc32c_optimization_init(void) +{ + crc32c_intel_probe(); + if (crc32c_intel_available) + crc_function = crc32c_intel; +} +#else + +void crc32c_optimization_init(void) +{ +} + +#endif /* __x86_64__ */ + +/* + * This is the CRC-32C table + * Generated with: + * width = 32 bits + * poly = 0x1EDC6F41 + * reflect input bytes = true + * reflect output bytes = true + */ + +static const u32 crc32c_table[256] = { + 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L, + 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL, + 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL, + 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L, + 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL, + 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L, + 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L, + 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL, + 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL, + 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L, + 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L, + 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL, + 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L, + 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL, + 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL, + 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L, + 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L, + 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L, + 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L, + 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L, + 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L, + 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L, + 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L, + 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L, + 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L, + 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L, + 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L, + 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L, + 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L, + 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L, + 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L, + 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L, + 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL, + 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L, + 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L, + 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL, + 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L, + 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL, + 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL, + 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L, + 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L, + 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL, + 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL, + 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L, + 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL, + 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L, + 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L, + 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL, + 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L, + 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL, + 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL, + 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L, + 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL, + 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L, + 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L, + 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL, + 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL, + 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L, + 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L, + 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL, + 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L, + 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL, + 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL, + 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L +}; + +/* + * Steps through buffer one byte at at time, calculates reflected + * crc using table. + */ + +u32 __crc32c_le(u32 crc, unsigned char const *data, size_t length) +{ + while (length--) + crc = + crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8); + return crc; +} + +u32 crc32c_le(u32 crc, unsigned char const *data, size_t length) +{ + return crc_function(crc, data, length); +} diff --git a/kernel-lib/crc32c.h b/kernel-lib/crc32c.h new file mode 100644 index 00000000..c552ef6e --- /dev/null +++ b/kernel-lib/crc32c.h @@ -0,0 +1,33 @@ +/* + * Copyright (C) 2007 Red Hat. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 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 for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef __CRC32C__ +#define __CRC32C__ + +#if BTRFS_FLAT_INCLUDES +#include "kerncompat.h" +#else +#include <btrfs/kerncompat.h> +#endif /* BTRFS_FLAT_INCLUDES */ + +u32 crc32c_le(u32 seed, unsigned char const *data, size_t length); +void crc32c_optimization_init(void); + +#define crc32c(seed, data, length) crc32c_le(seed, (unsigned char const *)data, length) +#define btrfs_crc32c crc32c +#endif diff --git a/kernel-lib/interval_tree_generic.h b/kernel-lib/interval_tree_generic.h new file mode 100644 index 00000000..e26c7322 --- /dev/null +++ b/kernel-lib/interval_tree_generic.h @@ -0,0 +1,193 @@ +/* + Interval Trees + (C) 2012 Michel Lespinasse <walken@google.com> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + 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 for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + include/linux/interval_tree_generic.h +*/ + +#include <stdbool.h> + +#include "rbtree_augmented.h" + +/* + * Template for implementing interval trees + * + * ITSTRUCT: struct type of the interval tree nodes + * ITRB: name of struct rb_node field within ITSTRUCT + * ITTYPE: type of the interval endpoints + * ITSUBTREE: name of ITTYPE field within ITSTRUCT holding last-in-subtree + * ITSTART(n): start endpoint of ITSTRUCT node n + * ITLAST(n): last endpoint of ITSTRUCT node n + * ITSTATIC: 'static' or empty + * ITPREFIX: prefix to use for the inline tree definitions + * + * Note - before using this, please consider if non-generic version + * (interval_tree.h) would work for you... + */ + +#define INTERVAL_TREE_DEFINE(ITSTRUCT, ITRB, ITTYPE, ITSUBTREE, \ + ITSTART, ITLAST, ITSTATIC, ITPREFIX) \ + \ +/* Callbacks for augmented rbtree insert and remove */ \ + \ +static inline ITTYPE ITPREFIX ## _compute_subtree_last(ITSTRUCT *node) \ +{ \ + ITTYPE max = ITLAST(node), subtree_last; \ + if (node->ITRB.rb_left) { \ + subtree_last = rb_entry(node->ITRB.rb_left, \ + ITSTRUCT, ITRB)->ITSUBTREE; \ + if (max < subtree_last) \ + max = subtree_last; \ + } \ + if (node->ITRB.rb_right) { \ + subtree_last = rb_entry(node->ITRB.rb_right, \ + ITSTRUCT, ITRB)->ITSUBTREE; \ + if (max < subtree_last) \ + max = subtree_last; \ + } \ + return max; \ +} \ + \ +RB_DECLARE_CALLBACKS(static, ITPREFIX ## _augment, ITSTRUCT, ITRB, \ + ITTYPE, ITSUBTREE, ITPREFIX ## _compute_subtree_last) \ + \ +/* Insert / remove interval nodes from the tree */ \ + \ +ITSTATIC void ITPREFIX ## _insert(ITSTRUCT *node, struct rb_root *root) \ +{ \ + struct rb_node **link = &root->rb_node, *rb_parent = NULL; \ + ITTYPE start = ITSTART(node), last = ITLAST(node); \ + ITSTRUCT *parent; \ + \ + while (*link) { \ + rb_parent = *link; \ + parent = rb_entry(rb_parent, ITSTRUCT, ITRB); \ + if (parent->ITSUBTREE < last) \ + parent->ITSUBTREE = last; \ + if (start < ITSTART(parent)) \ + link = &parent->ITRB.rb_left; \ + else \ + link = &parent->ITRB.rb_right; \ + } \ + \ + node->ITSUBTREE = last; \ + rb_link_node(&node->ITRB, rb_parent, link); \ + rb_insert_augmented(&node->ITRB, root, &ITPREFIX ## _augment); \ +} \ + \ +ITSTATIC void ITPREFIX ## _remove(ITSTRUCT *node, struct rb_root *root) \ +{ \ + rb_erase_augmented(&node->ITRB, root, &ITPREFIX ## _augment); \ +} \ + \ +/* \ + * Iterate over intervals intersecting [start;last] \ + * \ + * Note that a node's interval intersects [start;last] iff: \ + * Cond1: ITSTART(node) <= last \ + * and \ + * Cond2: start <= ITLAST(node) \ + */ \ + \ +static ITSTRUCT * \ +ITPREFIX ## _subtree_search(ITSTRUCT *node, ITTYPE start, ITTYPE last) \ +{ \ + while (true) { \ + /* \ + * Loop invariant: start <= node->ITSUBTREE \ + * (Cond2 is satisfied by one of the subtree nodes) \ + */ \ + if (node->ITRB.rb_left) { \ + ITSTRUCT *left = rb_entry(node->ITRB.rb_left, \ + ITSTRUCT, ITRB); \ + if (start <= left->ITSUBTREE) { \ + /* \ + * Some nodes in left subtree satisfy Cond2. \ + * Iterate to find the leftmost such node N. \ + * If it also satisfies Cond1, that's the \ + * match we are looking for. Otherwise, there \ + * is no matching interval as nodes to the \ + * right of N can't satisfy Cond1 either. \ + */ \ + node = left; \ + continue; \ + } \ + } \ + if (ITSTART(node) <= last) { /* Cond1 */ \ + if (start <= ITLAST(node)) /* Cond2 */ \ + return node; /* node is leftmost match */ \ + if (node->ITRB.rb_right) { \ + node = rb_entry(node->ITRB.rb_right, \ + ITSTRUCT, ITRB); \ + if (start <= node->ITSUBTREE) \ + continue; \ + } \ + } \ + return NULL; /* No match */ \ + } \ +} \ + \ +ITSTATIC ITSTRUCT * \ +ITPREFIX ## _iter_first(struct rb_root *root, ITTYPE start, ITTYPE last) \ +{ \ + ITSTRUCT *node; \ + \ + if (!root->rb_node) \ + return NULL; \ + node = rb_entry(root->rb_node, ITSTRUCT, ITRB); \ + if (node->ITSUBTREE < start) \ + return NULL; \ + return ITPREFIX ## _subtree_search(node, start, last); \ +} \ + \ +ITSTATIC ITSTRUCT * \ +ITPREFIX ## _iter_next(ITSTRUCT *node, ITTYPE start, ITTYPE last) \ +{ \ + struct rb_node *rb = node->ITRB.rb_right, *prev; \ + \ + while (true) { \ + /* \ + * Loop invariants: \ + * Cond1: ITSTART(node) <= last \ + * rb == node->ITRB.rb_right \ + * \ + * First, search right subtree if suitable \ + */ \ + if (rb) { \ + ITSTRUCT *right = rb_entry(rb, ITSTRUCT, ITRB); \ + if (start <= right->ITSUBTREE) \ + return ITPREFIX ## _subtree_search(right, \ + start, last); \ + } \ + \ + /* Move up the tree until we come from a node's left child */ \ + do { \ + rb = rb_parent(&node->ITRB); \ + if (!rb) \ + return NULL; \ + prev = &node->ITRB; \ + node = rb_entry(rb, ITSTRUCT, ITRB); \ + rb = node->ITRB.rb_right; \ + } while (prev == rb); \ + \ + /* Check if the node intersects [start;last] */ \ + if (last < ITSTART(node)) /* !Cond1 */ \ + return NULL; \ + else if (start <= ITLAST(node)) /* Cond2 */ \ + return node; \ + } \ +} diff --git a/kernel-lib/list.h b/kernel-lib/list.h new file mode 100644 index 00000000..db7a58c7 --- /dev/null +++ b/kernel-lib/list.h @@ -0,0 +1,486 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 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 for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef _LINUX_LIST_H +#define _LINUX_LIST_H + +#define LIST_POISON1 ((struct list_head *) 0x00100100) +#define LIST_POISON2 ((struct list_head *) 0x00200200) + +/* + * Simple doubly linked list implementation. + * + * Some of the internal functions ("__xxx") are useful when + * manipulating whole lists rather than single entries, as + * sometimes we already know the next/prev entries and we can + * generate better code by using them directly rather than + * using the generic single-entry routines. + */ + +struct list_head { + struct list_head *next, *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +static inline void INIT_LIST_HEAD(struct list_head *list) +{ + list->next = list; + list->prev = list; +} + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +#ifndef CONFIG_DEBUG_LIST +static inline void __list_add(struct list_head *xnew, + struct list_head *prev, + struct list_head *next) +{ + next->prev = xnew; + xnew->next = next; + xnew->prev = prev; + prev->next = xnew; +} +#else +extern void __list_add(struct list_head *xnew, + struct list_head *prev, + struct list_head *next); +#endif + +/** + * list_add - add a new entry + * @new: new entry to be added + * @head: list head to add it after + * + * Insert a new entry after the specified head. + * This is good for implementing stacks. + */ +#ifndef CONFIG_DEBUG_LIST +static inline void list_add(struct list_head *xnew, struct list_head *head) +{ + __list_add(xnew, head, head->next); +} +#else +extern void list_add(struct list_head *xnew, struct list_head *head); +#endif + + +/** + * list_add_tail - add a new entry + * @new: new entry to be added + * @head: list head to add it before + * + * Insert a new entry before the specified head. + * This is useful for implementing queues. + */ +static inline void list_add_tail(struct list_head *xnew, struct list_head *head) +{ + __list_add(xnew, head->prev, head); +} + +/* + * Delete a list entry by making the prev/next entries + * point to each other. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static inline void __list_del(struct list_head * prev, struct list_head * next) +{ + next->prev = prev; + prev->next = next; +} + +/** + * list_del - deletes entry from list. + * @entry: the element to delete from the list. + * Note: list_empty on entry does not return true after this, the entry is + * in an undefined state. + */ +#ifndef CONFIG_DEBUG_LIST +static inline void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + entry->next = LIST_POISON1; + entry->prev = LIST_POISON2; +} +#else +extern void list_del(struct list_head *entry); +#endif + +/** + * list_replace - replace old entry by new one + * @old : the element to be replaced + * @new : the new element to insert + * Note: if 'old' was empty, it will be overwritten. + */ +static inline void list_replace(struct list_head *old, + struct list_head *xnew) +{ + xnew->next = old->next; + xnew->next->prev = xnew; + xnew->prev = old->prev; + xnew->prev->next = xnew; +} + +static inline void list_replace_init(struct list_head *old, + struct list_head *xnew) +{ + list_replace(old, xnew); + INIT_LIST_HEAD(old); +} +/** + * list_del_init - deletes entry from list and reinitialize it. + * @entry: the element to delete from the list. + */ +static inline void list_del_init(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + INIT_LIST_HEAD(entry); +} + +/** + * list_move - delete from one list and add as another's head + * @list: the entry to move + * @head: the head that will precede our entry + */ +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add(list, head); +} + +/** + * list_move_tail - delete from one list and add as another's tail + * @list: the entry to move + * @head: the head that will follow our entry + */ +static inline void list_move_tail(struct list_head *list, + struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); +} + +/** + * list_is_last - tests whether @list is the last entry in list @head + * @list: the entry to test + * @head: the head of the list + */ +static inline int list_is_last(const struct list_head *list, + const struct list_head *head) +{ + return list->next == head; +} + +/** + * list_empty - tests whether a list is empty + * @head: the list to test. + */ +static inline int list_empty(const struct list_head *head) +{ + return head->next == head; +} + +/** + * list_empty_careful - tests whether a list is empty and not being modified + * @head: the list to test + * + * Description: + * tests whether a list is empty _and_ checks that no other CPU might be + * in the process of modifying either member (next or prev) + * + * NOTE: using list_empty_careful() without synchronization + * can only be safe if the only activity that can happen + * to the list entry is list_del_init(). Eg. it cannot be used + * if another CPU could re-list_add() it. + */ +static inline int list_empty_careful(const struct list_head *head) +{ + struct list_head *next = head->next; + return (next == head) && (next == head->prev); +} + +static inline void __list_splice(const struct list_head *list, + struct list_head *prev, + struct list_head *next) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + + first->prev = prev; + prev->next = first; + + last->next = next; + next->prev = last; +} + +/** + * list_splice - join two lists + * @list: the new list to add. + * @head: the place to add it in the first list. + */ +static inline void list_splice(struct list_head *list, struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head, head->next); +} + +/** + * list_splice_tail - join two lists, each list being a queue + * @list: the new list to add. + * @head: the place to add it in the first list. + */ +static inline void list_splice_tail(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head->prev, head); +} + +/** + * list_splice_init - join two lists and reinitialise the emptied list. + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * The list at @list is reinitialised + */ +static inline void list_splice_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head, head->next); + INIT_LIST_HEAD(list); + } +} + +/** + * list_splice_tail_init - join two lists and reinitialise the emptied list + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * Each of the lists is a queue. + * The list at @list is reinitialised + */ +static inline void list_splice_tail_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head->prev, head); + INIT_LIST_HEAD(list); + } +} + +/** + * list_entry - get the struct for this entry + * @ptr: the &struct list_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + */ +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +/** + * list_first_entry - get the first element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/** + * list_next_entry - get the next element from a list + * @ptr: the list head to take the element from. + * @member: the name of the list_struct within the struct. + * + * Note, that next is expected to be not null. + */ +#define list_next_entry(ptr, member) \ + list_entry((ptr)->member.next, typeof(*ptr), member) + +/** + * list_for_each - iterate over a list + * @pos: the &struct list_head to use as a loop cursor. + * @head: the head for your list. + */ +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); \ + pos = pos->next) + +/** + * __list_for_each - iterate over a list + * @pos: the &struct list_head to use as a loop cursor. + * @head: the head for your list. + * + * This variant differs from list_for_each() in that it's the + * simplest possible list iteration code, no prefetching is done. + * Use this for code that knows the list to be very short (empty + * or 1 entry) most of the time. + */ +#define __list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); pos = pos->next) + +/** + * list_for_each_prev - iterate over a list backwards + * @pos: the &struct list_head to use as a loop cursor. + * @head: the head for your list. + */ +#define list_for_each_prev(pos, head) \ + for (pos = (head)->prev; pos != (head); \ + pos = pos->prev) + +/** + * list_for_each_safe - iterate over a list safe against removal of list entry + * @pos: the &struct list_head to use as a loop cursor. + * @n: another &struct list_head to use as temporary storage + * @head: the head for your list. + */ +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +/** + * list_for_each_entry - iterate over list of given type + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +/** + * list_for_each_entry_reverse - iterate backwards over list of given type. + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_entry((head)->prev, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.prev, typeof(*pos), member)) + +/** + * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue + * @pos: the type * to use as a start point + * @head: the head of the list + * @member: the name of the list_struct within the struct. + * + * Prepares a pos entry for use as a start point in list_for_each_entry_continue. + */ +#define list_prepare_entry(pos, head, member) \ + ((pos) ? : list_entry(head, typeof(*pos), member)) + +/** + * list_for_each_entry_continue - continue iteration over list of given type + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Continue to iterate over list of given type, continuing after + * the current position. + */ +#define list_for_each_entry_continue(pos, head, member) \ + for (pos = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +/** + * list_for_each_entry_from - iterate over list of given type from the current point + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Iterate over list of given type, continuing from current position. + */ +#define list_for_each_entry_from(pos, head, member) \ + for (; &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +/** + * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + +/** + * list_for_each_entry_safe_continue + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Iterate over list of given type, continuing after current point, + * safe against removal of list entry. + */ +#define list_for_each_entry_safe_continue(pos, n, head, member) \ + for (pos = list_entry(pos->member.next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + +/** + * list_for_each_entry_safe_from + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Iterate over list of given type from current point, safe against + * removal of list entry. + */ +#define list_for_each_entry_safe_from(pos, n, head, member) \ + for (n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + +/** + * list_for_each_entry_safe_reverse + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Iterate backwards over list of given type, safe against removal + * of list entry. + */ +#define list_for_each_entry_safe_reverse(pos, n, head, member) \ + for (pos = list_entry((head)->prev, typeof(*pos), member), \ + n = list_entry(pos->member.prev, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.prev, typeof(*n), member)) + +#endif diff --git a/kernel-lib/list_sort.c b/kernel-lib/list_sort.c new file mode 100644 index 00000000..9e2c2024 --- /dev/null +++ b/kernel-lib/list_sort.c @@ -0,0 +1,144 @@ +/* + * taken from linux kernel lib/list_sort.c, removed unneeded code and adapted + * for btrfsprogs + */ + +#include "kerncompat.h" +#include "list_sort.h" +#include "list.h" + +#define MAX_LIST_LENGTH_BITS 20 + +/* + * Returns a list organized in an intermediate format suited + * to chaining of merge() calls: null-terminated, no reserved or + * sentinel head node, "prev" links not maintained. + */ +static struct list_head *merge(void *priv, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b), + struct list_head *a, struct list_head *b) +{ + struct list_head head, *tail = &head; + + while (a && b) { + /* if equal, take 'a' -- important for sort stability */ + if ((*cmp)(priv, a, b) <= 0) { + tail->next = a; + a = a->next; + } else { + tail->next = b; + b = b->next; + } + tail = tail->next; + } + tail->next = a?:b; + return head.next; +} + +/* + * Combine final list merge with restoration of standard doubly-linked + * list structure. This approach duplicates code from merge(), but + * runs faster than the tidier alternatives of either a separate final + * prev-link restoration pass, or maintaining the prev links + * throughout. + */ +static void merge_and_restore_back_links(void *priv, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b), + struct list_head *head, + struct list_head *a, struct list_head *b) +{ + struct list_head *tail = head; + + while (a && b) { + /* if equal, take 'a' -- important for sort stability */ + if ((*cmp)(priv, a, b) <= 0) { + tail->next = a; + a->prev = tail; + a = a->next; + } else { + tail->next = b; + b->prev = tail; + b = b->next; + } + tail = tail->next; + } + tail->next = a ? : b; + + do { + /* + * In worst cases this loop may run many iterations. + * Continue callbacks to the client even though no + * element comparison is needed, so the client's cmp() + * routine can invoke cond_resched() periodically. + */ + (*cmp)(priv, tail->next, tail->next); + + tail->next->prev = tail; + tail = tail->next; + } while (tail->next); + + tail->next = head; + head->prev = tail; +} + +/** + * list_sort - sort a list + * @priv: private data, opaque to list_sort(), passed to @cmp + * @head: the list to sort + * @cmp: the elements comparison function + * + * This function implements "merge sort", which has O(nlog(n)) + * complexity. + * + * The comparison function @cmp must return a negative value if @a + * should sort before @b, and a positive value if @a should sort after + * @b. If @a and @b are equivalent, and their original relative + * ordering is to be preserved, @cmp must return 0. + */ +void list_sort(void *priv, struct list_head *head, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b)) +{ + struct list_head *part[MAX_LIST_LENGTH_BITS+1]; /* sorted partial lists + -- last slot is a sentinel */ + int lev; /* index into part[] */ + int max_lev = 0; + struct list_head *list; + + if (list_empty(head)) + return; + + memset(part, 0, sizeof(part)); + + head->prev->next = NULL; + list = head->next; + + while (list) { + struct list_head *cur = list; + list = list->next; + cur->next = NULL; + + for (lev = 0; part[lev]; lev++) { + cur = merge(priv, cmp, part[lev], cur); + part[lev] = NULL; + } + if (lev > max_lev) { + if (lev >= ARRAY_SIZE(part)-1) { + printf("list_sort: list passed to" + " list_sort() too long for" + " efficiency\n"); + lev--; + } + max_lev = lev; + } + part[lev] = cur; + } + + for (lev = 0; lev < max_lev; lev++) + if (part[lev]) + list = merge(priv, cmp, part[lev], list); + + merge_and_restore_back_links(priv, cmp, head, part[max_lev], list); +} diff --git a/kernel-lib/list_sort.h b/kernel-lib/list_sort.h new file mode 100644 index 00000000..987cd5c4 --- /dev/null +++ b/kernel-lib/list_sort.h @@ -0,0 +1,14 @@ +/* + * taken from linux kernel include/list_sort.h + */ +#ifndef _LINUX_LIST_SORT_H +#define _LINUX_LIST_SORT_H + +#include "kerncompat.h" + +struct list_head; + +void list_sort(void *priv, struct list_head *head, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b)); +#endif diff --git a/kernel-lib/radix-tree.c b/kernel-lib/radix-tree.c new file mode 100644 index 00000000..f259ab56 --- /dev/null +++ b/kernel-lib/radix-tree.c @@ -0,0 +1,849 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 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 for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +/* + * Copyright (C) 2001 Momchil Velikov + * Portions Copyright (C) 2001 Christoph Hellwig + * Copyright (C) 2005 SGI, Christoph Lameter <clameter@sgi.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2, or (at + * your option) any later version. + * + * 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include "kerncompat.h" +#include "radix-tree.h" +#ifdef __KERNEL__ +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) +#else +#define RADIX_TREE_MAP_SHIFT 3 /* For more stressful testing */ +#endif + +#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT) +#define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1) + +#define RADIX_TREE_TAG_LONGS \ + ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG) + +struct radix_tree_node { + unsigned int count; + void *slots[RADIX_TREE_MAP_SIZE]; + unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; +}; + +struct radix_tree_path { + struct radix_tree_node *node; + int offset; +}; + +#define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) +#define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2) + +static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH] __read_mostly; + +/* + * Per-cpu pool of preloaded nodes + */ +struct radix_tree_preload { + int nr; + struct radix_tree_node *nodes[RADIX_TREE_MAX_PATH]; +}; +static struct radix_tree_preload radix_tree_preloads = { 0, }; + +static int internal_nodes = 0; +/* + * This assumes that the caller has performed appropriate preallocation, and + * 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 *ret; + ret = malloc(sizeof(struct radix_tree_node)); + if (ret) { + memset(ret, 0, sizeof(struct radix_tree_node)); + internal_nodes++; + } + return ret; +} + +static inline void +radix_tree_node_free(struct radix_tree_node *node) +{ + internal_nodes--; + free(node); +} + +/* + * Load up this CPU's radix_tree_node buffer with sufficient objects to + * ensure that the addition of a single element in the tree cannot fail. On + * success, return zero, with preemption disabled. On error, return -ENOMEM + * with preemption not disabled. + */ +int radix_tree_preload(gfp_t gfp_mask) +{ + struct radix_tree_preload *rtp; + struct radix_tree_node *node; + int ret = -ENOMEM; + + preempt_disable(); + rtp = &__get_cpu_var(radix_tree_preloads); + while (rtp->nr < ARRAY_SIZE(rtp->nodes)) { + preempt_enable(); + node = radix_tree_node_alloc(NULL); + if (node == NULL) + goto out; + preempt_disable(); + rtp = &__get_cpu_var(radix_tree_preloads); + if (rtp->nr < ARRAY_SIZE(rtp->nodes)) + rtp->nodes[rtp->nr++] = node; + else + radix_tree_node_free(node); + } + ret = 0; +out: + return ret; +} + +static inline void tag_set(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + __set_bit(offset, node->tags[tag]); +} + +static inline void tag_clear(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + __clear_bit(offset, node->tags[tag]); +} + +static inline int tag_get(struct radix_tree_node *node, unsigned int tag, + int offset) +{ + return test_bit(offset, node->tags[tag]); +} + +static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT)); +} + + +static inline void root_tag_clear(struct radix_tree_root *root, unsigned int tag) +{ + root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT)); +} + +static inline void root_tag_clear_all(struct radix_tree_root *root) +{ + root->gfp_mask &= __GFP_BITS_MASK; +} + +static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag) +{ + return (__force unsigned)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); +} + +/* + * Returns 1 if any slot in the node has this tag set. + * Otherwise returns 0. + */ +static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag) +{ + int idx; + for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { + if (node->tags[tag][idx]) + return 1; + } + return 0; +} + +/* + * Return the maximum key which can be store into a + * radix tree with height HEIGHT. + */ +static inline unsigned long radix_tree_maxindex(unsigned int height) +{ + return height_to_maxindex[height]; +} + +/* + * Extend a radix tree so it can store key @index. + */ +static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) +{ + struct radix_tree_node *node; + unsigned int height; + int tag; + + /* Figure out what the height should be. */ + height = root->height + 1; + while (index > radix_tree_maxindex(height)) + height++; + + if (root->rnode == NULL) { + root->height = height; + goto out; + } + + do { + if (!(node = radix_tree_node_alloc(root))) + return -ENOMEM; + + /* Increase the height. */ + node->slots[0] = root->rnode; + + /* 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); + } + + node->count = 1; + root->rnode = node; + root->height++; + } while (height > root->height); +out: + return 0; +} + +/** + * radix_tree_insert - insert into a radix tree + * @root: radix tree root + * @index: index key + * @item: item to insert + * + * Insert an item into the radix tree at position @index. + */ +int radix_tree_insert(struct radix_tree_root *root, + unsigned long index, void *item) +{ + struct radix_tree_node *node = NULL, *slot; + unsigned int height, shift; + int offset; + int error; + + /* Make sure the tree is high enough. */ + if (index > radix_tree_maxindex(root->height)) { + error = radix_tree_extend(root, index); + if (error) + return error; + } + + slot = root->rnode; + height = root->height; + shift = (height-1) * RADIX_TREE_MAP_SHIFT; + + offset = 0; /* uninitialised var warning */ + while (height > 0) { + if (slot == NULL) { + /* Have to add a child node. */ + if (!(slot = radix_tree_node_alloc(root))) + return -ENOMEM; + if (node) { + node->slots[offset] = slot; + node->count++; + } else + root->rnode = slot; + } + + /* Go a level down */ + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + node = slot; + slot = node->slots[offset]; + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } + + if (slot != NULL) + return -EEXIST; + + if (node) { + node->count++; + node->slots[offset] = item; + BUG_ON(tag_get(node, 0, offset)); + BUG_ON(tag_get(node, 1, offset)); + } else { + root->rnode = item; + BUG_ON(root_tag_get(root, 0)); + BUG_ON(root_tag_get(root, 1)); + } + + return 0; +} + +static inline void **__lookup_slot(struct radix_tree_root *root, + unsigned long index) +{ + unsigned int height, shift; + struct radix_tree_node **slot; + + height = root->height; + + if (index > radix_tree_maxindex(height)) + return NULL; + + if (height == 0 && root->rnode) + return (void *)&root->rnode; + + shift = (height-1) * RADIX_TREE_MAP_SHIFT; + slot = &root->rnode; + + while (height > 0) { + if (*slot == NULL) + return NULL; + + slot = (struct radix_tree_node **) + ((*slot)->slots + + ((index >> shift) & RADIX_TREE_MAP_MASK)); + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } + + return (void **)slot; +} + +/** + * radix_tree_lookup_slot - lookup a slot in a radix tree + * @root: radix tree root + * @index: index key + * + * Lookup the slot corresponding to the position @index in the radix tree + * @root. This is useful for update-if-exists operations. + */ +void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) +{ + return __lookup_slot(root, index); +} + +/** + * radix_tree_lookup - perform lookup operation on a radix tree + * @root: radix tree root + * @index: index key + * + * Lookup the item at the position @index in the radix tree @root. + */ +void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) +{ + void **slot; + + slot = __lookup_slot(root, index); + return slot != NULL ? *slot : NULL; +} + +/** + * radix_tree_tag_set - set a tag on a radix tree node + * @root: radix tree root + * @index: index key + * @tag: tag index + * + * Set the search tag (which must be < RADIX_TREE_MAX_TAGS) + * corresponding to @index in the radix tree. From + * the root all the way down to the leaf node. + * + * Returns the address of the tagged item. Setting a tag on a not-present + * item is a bug. + */ +void *radix_tree_tag_set(struct radix_tree_root *root, + unsigned long index, unsigned int tag) +{ + unsigned int height, shift; + struct radix_tree_node *slot; + + height = root->height; + BUG_ON(index > radix_tree_maxindex(height)); + + slot = root->rnode; + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + + while (height > 0) { + int offset; + + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + if (!tag_get(slot, tag, offset)) + tag_set(slot, tag, offset); + slot = slot->slots[offset]; + BUG_ON(slot == NULL); + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } + + /* set the root's tag bit */ + if (slot && !root_tag_get(root, tag)) + root_tag_set(root, tag); + + return slot; +} + +/** + * radix_tree_tag_clear - clear a tag on a radix tree node + * @root: radix tree root + * @index: index key + * @tag: tag index + * + * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS) + * corresponding to @index in the radix tree. If + * this causes the leaf node to have no tags set then clear the tag in the + * next-to-leaf node, etc. + * + * Returns the address of the tagged item on success, else NULL. ie: + * has the same return value and semantics as radix_tree_lookup(). + */ +void *radix_tree_tag_clear(struct radix_tree_root *root, + unsigned long index, unsigned int tag) +{ + struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; + struct radix_tree_node *slot = NULL; + unsigned int height, shift; + + height = root->height; + if (index > radix_tree_maxindex(height)) + goto out; + + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + pathp->node = NULL; + slot = root->rnode; + + while (height > 0) { + int offset; + + if (slot == NULL) + goto out; + + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + pathp[1].offset = offset; + pathp[1].node = slot; + slot = slot->slots[offset]; + pathp++; + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } + + if (slot == NULL) + goto out; + + while (pathp->node) { + if (!tag_get(pathp->node, tag, pathp->offset)) + goto out; + tag_clear(pathp->node, tag, pathp->offset); + if (any_tag_set(pathp->node, tag)) + goto out; + pathp--; + } + + /* clear the root's tag bit */ + if (root_tag_get(root, tag)) + root_tag_clear(root, tag); + +out: + return slot; +} + +#ifndef __KERNEL__ /* Only the test harness uses this at present */ +/** + * radix_tree_tag_get - get a tag on a radix tree node + * @root: radix tree root + * @index: index key + * @tag: tag index (< RADIX_TREE_MAX_TAGS) + * + * Return values: + * + * 0: tag not present or not set + * 1: tag set + */ +int radix_tree_tag_get(struct radix_tree_root *root, + unsigned long index, unsigned int tag) +{ + unsigned int height, shift; + struct radix_tree_node *slot; + int saw_unset_tag = 0; + + height = root->height; + if (index > radix_tree_maxindex(height)) + return 0; + + /* check the root's tag bit */ + if (!root_tag_get(root, tag)) + return 0; + + if (height == 0) + return 1; + + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + slot = root->rnode; + + for ( ; ; ) { + int offset; + + if (slot == NULL) + return 0; + + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + + /* + * This is just a debug check. Later, we can bale as soon as + * we see an unset tag. + */ + if (!tag_get(slot, tag, offset)) + saw_unset_tag = 1; + if (height == 1) { + int ret = tag_get(slot, tag, offset); + + BUG_ON(ret && saw_unset_tag); + return !!ret; + } + slot = slot->slots[offset]; + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } +} +#endif + +static unsigned int +__lookup(struct radix_tree_root *root, void **results, unsigned long index, + unsigned int max_items, unsigned long *next_index) +{ + unsigned int nr_found = 0; + unsigned int shift, height; + struct radix_tree_node *slot; + unsigned long i; + + height = root->height; + if (height == 0) { + if (root->rnode && index == 0) + results[nr_found++] = root->rnode; + goto out; + } + + shift = (height-1) * RADIX_TREE_MAP_SHIFT; + slot = root->rnode; + + for ( ; height > 1; height--) { + + for (i = (index >> shift) & RADIX_TREE_MAP_MASK ; + i < RADIX_TREE_MAP_SIZE; i++) { + if (slot->slots[i] != NULL) + break; + index &= ~((1UL << shift) - 1); + index += 1UL << shift; + if (index == 0) + goto out; /* 32-bit wraparound */ + } + if (i == RADIX_TREE_MAP_SIZE) + goto out; + + shift -= RADIX_TREE_MAP_SHIFT; + slot = slot->slots[i]; + } + + /* Bottom level: grab some items */ + for (i = index & RADIX_TREE_MAP_MASK; i < RADIX_TREE_MAP_SIZE; i++) { + index++; + if (slot->slots[i]) { + results[nr_found++] = slot->slots[i]; + if (nr_found == max_items) + goto out; + } + } +out: + *next_index = index; + return nr_found; +} + +/** + * radix_tree_gang_lookup - perform multiple lookup on a radix tree + * @root: radix tree root + * @results: where the results of the lookup are placed + * @first_index: start the lookup from this key + * @max_items: place up to this many items at *results + * + * Performs an index-ascending scan of the tree for present items. Places + * them at *@results and returns the number of items which were placed at + * *@results. + * + * The implementation is naive. + */ +unsigned int +radix_tree_gang_lookup(struct radix_tree_root *root, void **results, + unsigned long first_index, unsigned int max_items) +{ + const unsigned long max_index = radix_tree_maxindex(root->height); + unsigned long cur_index = first_index; + unsigned int ret = 0; + + while (ret < max_items) { + unsigned int nr_found; + unsigned long next_index; /* Index of next search */ + + if (cur_index > max_index) + break; + nr_found = __lookup(root, results + ret, cur_index, + max_items - ret, &next_index); + ret += nr_found; + if (next_index == 0) + break; + cur_index = next_index; + } + return ret; +} + +/* + * FIXME: the two tag_get()s here should use find_next_bit() instead of + * open-coding the search. + */ +static unsigned int +__lookup_tag(struct radix_tree_root *root, void **results, unsigned long index, + unsigned int max_items, unsigned long *next_index, unsigned int tag) +{ + unsigned int nr_found = 0; + unsigned int shift; + unsigned int height = root->height; + struct radix_tree_node *slot; + + if (height == 0) { + if (root->rnode && index == 0) + results[nr_found++] = root->rnode; + goto out; + } + + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + slot = root->rnode; + + do { + unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK; + + for ( ; i < RADIX_TREE_MAP_SIZE; i++) { + if (tag_get(slot, tag, i)) { + BUG_ON(slot->slots[i] == NULL); + break; + } + index &= ~((1UL << shift) - 1); + index += 1UL << shift; + if (index == 0) + goto out; /* 32-bit wraparound */ + } + if (i == RADIX_TREE_MAP_SIZE) + goto out; + height--; + if (height == 0) { /* Bottom level: grab some items */ + unsigned long j = index & RADIX_TREE_MAP_MASK; + + for ( ; j < RADIX_TREE_MAP_SIZE; j++) { + index++; + if (tag_get(slot, tag, j)) { + BUG_ON(slot->slots[j] == NULL); + results[nr_found++] = slot->slots[j]; + if (nr_found == max_items) + goto out; + } + } + } + shift -= RADIX_TREE_MAP_SHIFT; + slot = slot->slots[i]; + } while (height > 0); +out: + *next_index = index; + return nr_found; +} + +/** + * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree + * based on a tag + * @root: radix tree root + * @results: where the results of the lookup are placed + * @first_index: start the lookup from this key + * @max_items: place up to this many items at *results + * @tag: the tag index (< RADIX_TREE_MAX_TAGS) + * + * Performs an index-ascending scan of the tree for present items which + * have the tag indexed by @tag set. Places the items at *@results and + * returns the number of items which were placed at *@results. + */ +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) +{ + const unsigned long max_index = radix_tree_maxindex(root->height); + unsigned long cur_index = first_index; + unsigned int ret = 0; + + /* check the root's tag bit */ + if (!root_tag_get(root, tag)) + return 0; + + while (ret < max_items) { + unsigned int nr_found; + unsigned long next_index; /* Index of next search */ + + if (cur_index > max_index) + break; + nr_found = __lookup_tag(root, results + ret, cur_index, + max_items - ret, &next_index, tag); + ret += nr_found; + if (next_index == 0) + break; + cur_index = next_index; + } + return ret; +} + +/** + * radix_tree_shrink - shrink height of a radix tree to minimal + * @root radix tree root + */ +static inline void radix_tree_shrink(struct radix_tree_root *root) +{ + /* try to shrink tree height */ + while (root->height > 0 && + root->rnode->count == 1 && + root->rnode->slots[0]) { + struct radix_tree_node *to_free = root->rnode; + + root->rnode = to_free->slots[0]; + root->height--; + /* must only free zeroed nodes into the slab */ + tag_clear(to_free, 0, 0); + tag_clear(to_free, 1, 0); + to_free->slots[0] = NULL; + to_free->count = 0; + radix_tree_node_free(to_free); + } +} + +/** + * radix_tree_delete - delete an item from a radix tree + * @root: radix tree root + * @index: index key + * + * Remove the item at @index from the radix tree rooted at @root. + * + * Returns the address of the deleted item, or NULL if it was not present. + */ +void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) +{ + struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; + struct radix_tree_node *slot = NULL; + unsigned int height, shift; + int tag; + int offset; + + height = root->height; + if (index > radix_tree_maxindex(height)) + goto out; + + slot = root->rnode; + if (height == 0 && root->rnode) { + root_tag_clear_all(root); + root->rnode = NULL; + goto out; + } + + shift = (height - 1) * RADIX_TREE_MAP_SHIFT; + pathp->node = NULL; + + do { + if (slot == NULL) + goto out; + + pathp++; + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + pathp->offset = offset; + pathp->node = slot; + slot = slot->slots[offset]; + shift -= RADIX_TREE_MAP_SHIFT; + height--; + } while (height > 0); + + if (slot == NULL) + goto out; + + /* + * Clear all tags associated with the just-deleted item + */ + for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { + if (tag_get(pathp->node, tag, pathp->offset)) + radix_tree_tag_clear(root, index, tag); + } + + /* Now free the nodes we do not need anymore */ + while (pathp->node) { + pathp->node->slots[pathp->offset] = NULL; + pathp->node->count--; + + if (pathp->node->count) { + if (pathp->node == root->rnode) + radix_tree_shrink(root); + goto out; + } + + /* Node with zero slots in use so free it */ + radix_tree_node_free(pathp->node); + + pathp--; + } + root_tag_clear_all(root); + root->height = 0; + root->rnode = NULL; + +out: + return slot; +} + +/** + * radix_tree_tagged - test whether any items in the tree are tagged + * @root: radix tree root + * @tag: tag to test + */ +int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) +{ + return root_tag_get(root, tag); +} + +static unsigned long __maxindex(unsigned int height) +{ + unsigned int tmp = height * RADIX_TREE_MAP_SHIFT; + unsigned long index = ~0UL; + + if (tmp < RADIX_TREE_INDEX_BITS) + index = (index >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1; + return index; +} + +static void radix_tree_init_maxindex(void) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++) + height_to_maxindex[i] = __maxindex(i); +} + +void radix_tree_init(void) +{ + radix_tree_init_maxindex(); +} diff --git a/kernel-lib/radix-tree.h b/kernel-lib/radix-tree.h new file mode 100644 index 00000000..bf96d839 --- /dev/null +++ b/kernel-lib/radix-tree.h @@ -0,0 +1,97 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 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 for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +/* + * Copyright (C) 2001 Momchil Velikov + * Portions Copyright (C) 2001 Christoph Hellwig + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2, or (at + * your option) any later version. + * + * 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +#ifndef _LINUX_RADIX_TREE_H +#define _LINUX_RADIX_TREE_H + +#if BTRFS_FLAT_INCLUDES +#include "kerncompat.h" +#else +#include <btrfs/kerncompat.h> +#endif /* BTRFS_FLAT_INCLUDES */ + +#define RADIX_TREE_MAX_TAGS 2 + +/* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */ +struct radix_tree_root { + unsigned int height; + gfp_t gfp_mask; + struct radix_tree_node *rnode; +}; + +#define RADIX_TREE_INIT(mask) { \ + .height = 0, \ + .gfp_mask = (mask), \ + .rnode = NULL, \ +} + +#define RADIX_TREE(name, mask) \ + struct radix_tree_root name = RADIX_TREE_INIT(mask) + +#define INIT_RADIX_TREE(root, mask) \ +do { \ + (root)->height = 0; \ + (root)->gfp_mask = (mask); \ + (root)->rnode = NULL; \ +} while (0) + +int radix_tree_insert(struct radix_tree_root *, unsigned long, void *); +void *radix_tree_lookup(struct radix_tree_root *, unsigned long); +void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long); +void *radix_tree_delete(struct radix_tree_root *, unsigned long); +unsigned int +radix_tree_gang_lookup(struct radix_tree_root *root, void **results, + unsigned long first_index, unsigned int max_items); +int radix_tree_preload(gfp_t gfp_mask); +void radix_tree_init(void); +void *radix_tree_tag_set(struct radix_tree_root *root, + unsigned long index, unsigned int tag); +void *radix_tree_tag_clear(struct radix_tree_root *root, + unsigned long index, unsigned int tag); +int radix_tree_tag_get(struct radix_tree_root *root, + unsigned long index, 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); +int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag); + +static inline void radix_tree_preload_end(void) +{ + preempt_enable(); +} + +#endif /* _LINUX_RADIX_TREE_H */ diff --git a/kernel-lib/rbtree.c b/kernel-lib/rbtree.c new file mode 100644 index 00000000..92590a57 --- /dev/null +++ b/kernel-lib/rbtree.c @@ -0,0 +1,548 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli <andrea@suse.de> + (C) 2002 David Woodhouse <dwmw2@infradead.org> + (C) 2012 Michel Lespinasse <walken@google.com> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + 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 for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + linux/lib/rbtree.c +*/ + +#include "rbtree_augmented.h" + +/* + * red-black trees properties: http://en.wikipedia.org/wiki/Rbtree + * + * 1) A node is either red or black + * 2) The root is black + * 3) All leaves (NULL) are black + * 4) Both children of every red node are black + * 5) Every simple path from root to leaves contains the same number + * of black nodes. + * + * 4 and 5 give the O(log n) guarantee, since 4 implies you cannot have two + * consecutive red nodes in a path and every red node is therefore followed by + * a black. So if B is the number of black nodes on every simple path (as per + * 5), then the longest possible path due to 4 is 2B. + * + * We shall indicate color with case, where black nodes are uppercase and red + * nodes will be lowercase. Unknown color nodes shall be drawn as red within + * parentheses and have some accompanying text comment. + */ + +static inline void rb_set_black(struct rb_node *rb) +{ + rb->__rb_parent_color |= RB_BLACK; +} + +static inline struct rb_node *rb_red_parent(struct rb_node *red) +{ + return (struct rb_node *)red->__rb_parent_color; +} + +/* + * Helper function for rotations: + * - old's parent and color get assigned to new + * - old gets assigned new as a parent and 'color' as a color. + */ +static inline void +__rb_rotate_set_parents(struct rb_node *old, struct rb_node *new, + struct rb_root *root, int color) +{ + struct rb_node *parent = rb_parent(old); + new->__rb_parent_color = old->__rb_parent_color; + rb_set_parent_color(old, new, color); + __rb_change_child(old, new, parent, root); +} + +static __always_inline void +__rb_insert(struct rb_node *node, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) +{ + struct rb_node *parent = rb_red_parent(node), *gparent, *tmp; + + while (true) { + /* + * Loop invariant: node is red + * + * If there is a black parent, we are done. + * Otherwise, take some corrective action as we don't + * want a red root or two consecutive red nodes. + */ + if (!parent) { + rb_set_parent_color(node, NULL, RB_BLACK); + break; + } else if (rb_is_black(parent)) + break; + + gparent = rb_red_parent(parent); + + tmp = gparent->rb_right; + if (parent != tmp) { /* parent == gparent->rb_left */ + if (tmp && rb_is_red(tmp)) { + /* + * Case 1 - color flips + * + * G g + * / \ / \ + * p u --> P U + * / / + * n n + * + * However, since g's parent might be red, and + * 4) does not allow this, we need to recurse + * at g. + */ + rb_set_parent_color(tmp, gparent, RB_BLACK); + rb_set_parent_color(parent, gparent, RB_BLACK); + node = gparent; + parent = rb_parent(node); + rb_set_parent_color(node, parent, RB_RED); + continue; + } + + tmp = parent->rb_right; + if (node == tmp) { + /* + * Case 2 - left rotate at parent + * + * G G + * / \ / \ + * p U --> n U + * \ / + * n p + * + * This still leaves us in violation of 4), the + * continuation into Case 3 will fix that. + */ + parent->rb_right = tmp = node->rb_left; + node->rb_left = parent; + if (tmp) + rb_set_parent_color(tmp, parent, + RB_BLACK); + rb_set_parent_color(parent, node, RB_RED); + augment_rotate(parent, node); + parent = node; + tmp = node->rb_right; + } + + /* + * Case 3 - right rotate at gparent + * + * G P + * / \ / \ + * p U --> n g + * / \ + * n U + */ + gparent->rb_left = tmp; /* == parent->rb_right */ + parent->rb_right = gparent; + if (tmp) + rb_set_parent_color(tmp, gparent, RB_BLACK); + __rb_rotate_set_parents(gparent, parent, root, RB_RED); + augment_rotate(gparent, parent); + break; + } else { + tmp = gparent->rb_left; + if (tmp && rb_is_red(tmp)) { + /* Case 1 - color flips */ + rb_set_parent_color(tmp, gparent, RB_BLACK); + rb_set_parent_color(parent, gparent, RB_BLACK); + node = gparent; + parent = rb_parent(node); + rb_set_parent_color(node, parent, RB_RED); + continue; + } + + tmp = parent->rb_left; + if (node == tmp) { + /* Case 2 - right rotate at parent */ + parent->rb_left = tmp = node->rb_right; + node->rb_right = parent; + if (tmp) + rb_set_parent_color(tmp, parent, + RB_BLACK); + rb_set_parent_color(parent, node, RB_RED); + augment_rotate(parent, node); + parent = node; + tmp = node->rb_left; + } + + /* Case 3 - left rotate at gparent */ + gparent->rb_right = tmp; /* == parent->rb_left */ + parent->rb_left = gparent; + if (tmp) + rb_set_parent_color(tmp, gparent, RB_BLACK); + __rb_rotate_set_parents(gparent, parent, root, RB_RED); + augment_rotate(gparent, parent); + break; + } + } +} + +/* + * Inline version for rb_erase() use - we want to be able to inline + * and eliminate the dummy_rotate callback there + */ +static __always_inline void +____rb_erase_color(struct rb_node *parent, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) +{ + struct rb_node *node = NULL, *sibling, *tmp1, *tmp2; + + while (true) { + /* + * Loop invariants: + * - node is black (or NULL on first iteration) + * - node is not the root (parent is not NULL) + * - All leaf paths going through parent and node have a + * black node count that is 1 lower than other leaf paths. + */ + sibling = parent->rb_right; + if (node != sibling) { /* node == parent->rb_left */ + if (rb_is_red(sibling)) { + /* + * Case 1 - left rotate at parent + * + * P S + * / \ / \ + * N s --> p Sr + * / \ / \ + * Sl Sr N Sl + */ + parent->rb_right = tmp1 = sibling->rb_left; + sibling->rb_left = parent; + rb_set_parent_color(tmp1, parent, RB_BLACK); + __rb_rotate_set_parents(parent, sibling, root, + RB_RED); + augment_rotate(parent, sibling); + sibling = tmp1; + } + tmp1 = sibling->rb_right; + if (!tmp1 || rb_is_black(tmp1)) { + tmp2 = sibling->rb_left; + if (!tmp2 || rb_is_black(tmp2)) { + /* + * Case 2 - sibling color flip + * (p could be either color here) + * + * (p) (p) + * / \ / \ + * N S --> N s + * / \ / \ + * Sl Sr Sl Sr + * + * This leaves us violating 5) which + * can be fixed by flipping p to black + * if it was red, or by recursing at p. + * p is red when coming from Case 1. + */ + rb_set_parent_color(sibling, parent, + RB_RED); + if (rb_is_red(parent)) + rb_set_black(parent); + else { + node = parent; + parent = rb_parent(node); + if (parent) + continue; + } + break; + } + /* + * Case 3 - right rotate at sibling + * (p could be either color here) + * + * (p) (p) + * / \ / \ + * N S --> N Sl + * / \ \ + * sl Sr s + * \ + * Sr + */ + sibling->rb_left = tmp1 = tmp2->rb_right; + tmp2->rb_right = sibling; + parent->rb_right = tmp2; + if (tmp1) + rb_set_parent_color(tmp1, sibling, + RB_BLACK); + augment_rotate(sibling, tmp2); + tmp1 = sibling; + sibling = tmp2; + } + /* + * Case 4 - left rotate at parent + color flips + * (p and sl could be either color here. + * After rotation, p becomes black, s acquires + * p's color, and sl keeps its color) + * + * (p) (s) + * / \ / \ + * N S --> P Sr + * / \ / \ + * (sl) sr N (sl) + */ + parent->rb_right = tmp2 = sibling->rb_left; + sibling->rb_left = parent; + rb_set_parent_color(tmp1, sibling, RB_BLACK); + if (tmp2) + rb_set_parent(tmp2, parent); + __rb_rotate_set_parents(parent, sibling, root, + RB_BLACK); + augment_rotate(parent, sibling); + break; + } else { + sibling = parent->rb_left; + if (rb_is_red(sibling)) { + /* Case 1 - right rotate at parent */ + parent->rb_left = tmp1 = sibling->rb_right; + sibling->rb_right = parent; + rb_set_parent_color(tmp1, parent, RB_BLACK); + __rb_rotate_set_parents(parent, sibling, root, + RB_RED); + augment_rotate(parent, sibling); + sibling = tmp1; + } + tmp1 = sibling->rb_left; + if (!tmp1 || rb_is_black(tmp1)) { + tmp2 = sibling->rb_right; + if (!tmp2 || rb_is_black(tmp2)) { + /* Case 2 - sibling color flip */ + rb_set_parent_color(sibling, parent, + RB_RED); + if (rb_is_red(parent)) + rb_set_black(parent); + else { + node = parent; + parent = rb_parent(node); + if (parent) + continue; + } + break; + } + /* Case 3 - right rotate at sibling */ + sibling->rb_right = tmp1 = tmp2->rb_left; + tmp2->rb_left = sibling; + parent->rb_left = tmp2; + if (tmp1) + rb_set_parent_color(tmp1, sibling, + RB_BLACK); + augment_rotate(sibling, tmp2); + tmp1 = sibling; + sibling = tmp2; + } + /* Case 4 - left rotate at parent + color flips */ + parent->rb_left = tmp2 = sibling->rb_right; + sibling->rb_right = parent; + rb_set_parent_color(tmp1, sibling, RB_BLACK); + if (tmp2) + rb_set_parent(tmp2, parent); + __rb_rotate_set_parents(parent, sibling, root, + RB_BLACK); + augment_rotate(parent, sibling); + break; + } + } +} + +/* Non-inline version for rb_erase_augmented() use */ +void __rb_erase_color(struct rb_node *parent, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) +{ + ____rb_erase_color(parent, root, augment_rotate); +} + +/* + * Non-augmented rbtree manipulation functions. + * + * We use dummy augmented callbacks here, and have the compiler optimize them + * out of the rb_insert_color() and rb_erase() function definitions. + */ + +static inline void dummy_propagate(struct rb_node *node, struct rb_node *stop) {} +static inline void dummy_copy(struct rb_node *old, struct rb_node *new) {} +static inline void dummy_rotate(struct rb_node *old, struct rb_node *new) {} + +static const struct rb_augment_callbacks dummy_callbacks = { + dummy_propagate, dummy_copy, dummy_rotate +}; + +void rb_insert_color(struct rb_node *node, struct rb_root *root) +{ + __rb_insert(node, root, dummy_rotate); +} + +void rb_erase(struct rb_node *node, struct rb_root *root) +{ + struct rb_node *rebalance; + rebalance = __rb_erase_augmented(node, root, &dummy_callbacks); + if (rebalance) + ____rb_erase_color(rebalance, root, dummy_rotate); +} + +/* + * Augmented rbtree manipulation functions. + * + * This instantiates the same __always_inline functions as in the non-augmented + * case, but this time with user-defined callbacks. + */ + +void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) +{ + __rb_insert(node, root, augment_rotate); +} + +/* + * This function returns the first node (in sort order) of the tree. + */ +struct rb_node *rb_first(const struct rb_root *root) +{ + struct rb_node *n; + + n = root->rb_node; + if (!n) + return NULL; + while (n->rb_left) + n = n->rb_left; + return n; +} + +struct rb_node *rb_last(const struct rb_root *root) +{ + struct rb_node *n; + + n = root->rb_node; + if (!n) + return NULL; + while (n->rb_right) + n = n->rb_right; + return n; +} + +struct rb_node *rb_next(const struct rb_node *node) +{ + struct rb_node *parent; + + if (RB_EMPTY_NODE(node)) + return NULL; + + /* + * If we have a right-hand child, go down and then left as far + * as we can. + */ + if (node->rb_right) { + node = node->rb_right; + while (node->rb_left) + node=node->rb_left; + return (struct rb_node *)node; + } + + /* + * No right-hand children. Everything down and left is smaller than us, + * so any 'next' node must be in the general direction of our parent. + * Go up the tree; any time the ancestor is a right-hand child of its + * parent, keep going up. First time it's a left-hand child of its + * parent, said parent is our 'next' node. + */ + while ((parent = rb_parent(node)) && node == parent->rb_right) + node = parent; + + return parent; +} + +struct rb_node *rb_prev(const struct rb_node *node) +{ + struct rb_node *parent; + + if (RB_EMPTY_NODE(node)) + return NULL; + + /* + * If we have a left-hand child, go down and then right as far + * as we can. + */ + if (node->rb_left) { + node = node->rb_left; + while (node->rb_right) + node=node->rb_right; + return (struct rb_node *)node; + } + + /* + * No left-hand children. Go up till we find an ancestor which + * is a right-hand child of its parent. + */ + while ((parent = rb_parent(node)) && node == parent->rb_left) + node = parent; + + return parent; +} + +void rb_replace_node(struct rb_node *victim, struct rb_node *new, + struct rb_root *root) +{ + struct rb_node *parent = rb_parent(victim); + + /* Set the surrounding nodes to point to the replacement */ + __rb_change_child(victim, new, parent, root); + if (victim->rb_left) + rb_set_parent(victim->rb_left, new); + if (victim->rb_right) + rb_set_parent(victim->rb_right, new); + + /* Copy the pointers/colour from the victim to the replacement */ + *new = *victim; +} + +static struct rb_node *rb_left_deepest_node(const struct rb_node *node) +{ + for (;;) { + if (node->rb_left) + node = node->rb_left; + else if (node->rb_right) + node = node->rb_right; + else + return (struct rb_node *)node; + } +} + +struct rb_node *rb_next_postorder(const struct rb_node *node) +{ + const struct rb_node *parent; + if (!node) + return NULL; + parent = rb_parent(node); + + /* If we're sitting on node, we've already seen our children */ + if (parent && node == parent->rb_left && parent->rb_right) { + /* If we are the parent's left node, go to the parent's right + * node then all the way down to the left */ + return rb_left_deepest_node(parent->rb_right); + } else + /* Otherwise we are the parent's right node, and the parent + * should be next */ + return (struct rb_node *)parent; +} + +struct rb_node *rb_first_postorder(const struct rb_root *root) +{ + if (!root->rb_node) + return NULL; + + return rb_left_deepest_node(root->rb_node); +} diff --git a/kernel-lib/rbtree.h b/kernel-lib/rbtree.h new file mode 100644 index 00000000..47b662a3 --- /dev/null +++ b/kernel-lib/rbtree.h @@ -0,0 +1,118 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli <andrea@suse.de> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + 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 for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + linux/include/linux/rbtree.h + + To use rbtrees you'll have to implement your own insert and search cores. + This will avoid us to use callbacks and to drop drammatically performances. + I know it's not the cleaner way, but in C (not in C++) to get + performances and genericity... + + See Documentation/rbtree.txt for documentation and samples. +*/ + +#ifndef _LINUX_RBTREE_H +#define _LINUX_RBTREE_H +#if BTRFS_FLAT_INCLUDES +#include "kerncompat.h" +#else +#include <btrfs/kerncompat.h> +#endif /* BTRFS_FLAT_INCLUDES */ + +#ifdef __cplusplus +extern "C" { +#endif + +struct rb_node { + unsigned long __rb_parent_color; + struct rb_node *rb_right; + struct rb_node *rb_left; +} __attribute__((aligned(sizeof(long)))); + /* The alignment might seem pointless, but allegedly CRIS needs it */ + +struct rb_root { + struct rb_node *rb_node; +}; + + +#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) + +#define RB_ROOT (struct rb_root) { NULL, } +#define rb_entry(ptr, type, member) container_of(ptr, type, member) + +#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL) + +/* 'empty' nodes are nodes that are known not to be inserted in an rtbree */ +#define RB_EMPTY_NODE(node) \ + ((node)->__rb_parent_color == (unsigned long)(node)) +#define RB_CLEAR_NODE(node) \ + ((node)->__rb_parent_color = (unsigned long)(node)) + + +extern void rb_insert_color(struct rb_node *, struct rb_root *); +extern void rb_erase(struct rb_node *, struct rb_root *); + + +/* Find logical next and previous nodes in a tree */ +extern struct rb_node *rb_next(const struct rb_node *); +extern struct rb_node *rb_prev(const struct rb_node *); +extern struct rb_node *rb_first(const struct rb_root *); +extern struct rb_node *rb_last(const struct rb_root *); + +/* Postorder iteration - always visit the parent after its children */ +extern struct rb_node *rb_first_postorder(const struct rb_root *); +extern struct rb_node *rb_next_postorder(const struct rb_node *); + +/* Fast replacement of a single node without remove/rebalance/add/rebalance */ +extern void rb_replace_node(struct rb_node *victim, struct rb_node *new_node, + struct rb_root *root); + +static inline void rb_link_node(struct rb_node * node, struct rb_node * parent, + struct rb_node ** rb_link) +{ + node->__rb_parent_color = (unsigned long)parent; + node->rb_left = node->rb_right = NULL; + + *rb_link = node; +} + +#define rb_entry_safe(ptr, type, member) \ + ({ typeof(ptr) ____ptr = (ptr); \ + ____ptr ? rb_entry(____ptr, type, member) : NULL; \ + }) + +/** + * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of + * given type safe against removal of rb_node entry + * + * @pos: the 'type *' to use as a loop cursor. + * @n: another 'type *' to use as temporary storage + * @root: 'rb_root *' of the rbtree. + * @field: the name of the rb_node field within 'type'. + */ +#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ + for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ + pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ + typeof(*pos), field); 1; }); \ + pos = n) + +#ifdef __cplusplus +} +#endif + +#endif /* _LINUX_RBTREE_H */ diff --git a/kernel-lib/rbtree_augmented.h b/kernel-lib/rbtree_augmented.h new file mode 100644 index 00000000..5d269784 --- /dev/null +++ b/kernel-lib/rbtree_augmented.h @@ -0,0 +1,249 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli <andrea@suse.de> + (C) 2002 David Woodhouse <dwmw2@infradead.org> + (C) 2012 Michel Lespinasse <walken@google.com> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + 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 for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + linux/include/linux/rbtree_augmented.h +*/ + +#ifndef _LINUX_RBTREE_AUGMENTED_H +#define _LINUX_RBTREE_AUGMENTED_H + +#include "rbtree.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * Please note - only struct rb_augment_callbacks and the prototypes for + * rb_insert_augmented() and rb_erase_augmented() are intended to be public. + * The rest are implementation details you are not expected to depend on. + * + * See Documentation/rbtree.txt for documentation and samples. + */ + +struct rb_augment_callbacks { + void (*propagate)(struct rb_node *node, struct rb_node *stop); + void (*copy)(struct rb_node *old, struct rb_node *new); + void (*rotate)(struct rb_node *old, struct rb_node *new); +}; + +extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); +/* + * Fixup the rbtree and update the augmented information when rebalancing. + * + * On insertion, the user must update the augmented information on the path + * leading to the inserted node, then call rb_link_node() as usual and + * rb_augment_inserted() instead of the usual rb_insert_color() call. + * If rb_augment_inserted() rebalances the rbtree, it will callback into + * a user provided function to update the augmented information on the + * affected subtrees. + */ +static inline void +rb_insert_augmented(struct rb_node *node, struct rb_root *root, + const struct rb_augment_callbacks *augment) +{ + __rb_insert_augmented(node, root, augment->rotate); +} + +#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \ + rbtype, rbaugmented, rbcompute) \ +static inline void \ +rbname ## _propagate(struct rb_node *rb, struct rb_node *stop) \ +{ \ + while (rb != stop) { \ + rbstruct *node = rb_entry(rb, rbstruct, rbfield); \ + rbtype augmented = rbcompute(node); \ + if (node->rbaugmented == augmented) \ + break; \ + node->rbaugmented = augmented; \ + rb = rb_parent(&node->rbfield); \ + } \ +} \ +static inline void \ +rbname ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ +{ \ + rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ + rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ + new->rbaugmented = old->rbaugmented; \ +} \ +static void \ +rbname ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \ +{ \ + rbstruct *old = rb_entry(rb_old, rbstruct, rbfield); \ + rbstruct *new = rb_entry(rb_new, rbstruct, rbfield); \ + new->rbaugmented = old->rbaugmented; \ + old->rbaugmented = rbcompute(old); \ +} \ +rbstatic const struct rb_augment_callbacks rbname = { \ + rbname ## _propagate, rbname ## _copy, rbname ## _rotate \ +}; + + +#define RB_RED 0 +#define RB_BLACK 1 + +#define __rb_parent(pc) ((struct rb_node *)(pc & ~3)) + +#define __rb_color(pc) ((pc) & 1) +#define __rb_is_black(pc) __rb_color(pc) +#define __rb_is_red(pc) (!__rb_color(pc)) +#define rb_color(rb) __rb_color((rb)->__rb_parent_color) +#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color) +#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color) + +static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) +{ + rb->__rb_parent_color = rb_color(rb) | (unsigned long)p; +} + +static inline void rb_set_parent_color(struct rb_node *rb, + struct rb_node *p, int color) +{ + rb->__rb_parent_color = (unsigned long)p | color; +} + +static inline void +__rb_change_child(struct rb_node *old, struct rb_node *new, + struct rb_node *parent, struct rb_root *root) +{ + if (parent) { + if (parent->rb_left == old) + parent->rb_left = new; + else + parent->rb_right = new; + } else + root->rb_node = new; +} + +extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); + +static __always_inline struct rb_node * +__rb_erase_augmented(struct rb_node *node, struct rb_root *root, + const struct rb_augment_callbacks *augment) +{ + struct rb_node *child = node->rb_right, *tmp = node->rb_left; + struct rb_node *parent, *rebalance; + unsigned long pc; + + if (!tmp) { + /* + * Case 1: node to erase has no more than 1 child (easy!) + * + * Note that if there is one child it must be red due to 5) + * and node must be black due to 4). We adjust colors locally + * so as to bypass __rb_erase_color() later on. + */ + pc = node->__rb_parent_color; + parent = __rb_parent(pc); + __rb_change_child(node, child, parent, root); + if (child) { + child->__rb_parent_color = pc; + rebalance = NULL; + } else + rebalance = __rb_is_black(pc) ? parent : NULL; + tmp = parent; + } else if (!child) { + /* Still case 1, but this time the child is node->rb_left */ + tmp->__rb_parent_color = pc = node->__rb_parent_color; + parent = __rb_parent(pc); + __rb_change_child(node, tmp, parent, root); + rebalance = NULL; + tmp = parent; + } else { + struct rb_node *successor = child, *child2; + tmp = child->rb_left; + if (!tmp) { + /* + * Case 2: node's successor is its right child + * + * (n) (s) + * / \ / \ + * (x) (s) -> (x) (c) + * \ + * (c) + */ + parent = successor; + child2 = successor->rb_right; + augment->copy(node, successor); + } else { + /* + * Case 3: node's successor is leftmost under + * node's right child subtree + * + * (n) (s) + * / \ / \ + * (x) (y) -> (x) (y) + * / / + * (p) (p) + * / / + * (s) (c) + * \ + * (c) + */ + do { + parent = successor; + successor = tmp; + tmp = tmp->rb_left; + } while (tmp); + parent->rb_left = child2 = successor->rb_right; + successor->rb_right = child; + rb_set_parent(child, successor); + augment->copy(node, successor); + augment->propagate(parent, successor); + } + + successor->rb_left = tmp = node->rb_left; + rb_set_parent(tmp, successor); + + pc = node->__rb_parent_color; + tmp = __rb_parent(pc); + __rb_change_child(node, successor, tmp, root); + if (child2) { + successor->__rb_parent_color = pc; + rb_set_parent_color(child2, parent, RB_BLACK); + rebalance = NULL; + } else { + unsigned long pc2 = successor->__rb_parent_color; + successor->__rb_parent_color = pc; + rebalance = __rb_is_black(pc2) ? parent : NULL; + } + tmp = successor; + } + + augment->propagate(tmp, NULL); + return rebalance; +} + +static __always_inline void +rb_erase_augmented(struct rb_node *node, struct rb_root *root, + const struct rb_augment_callbacks *augment) +{ + struct rb_node *rebalance = __rb_erase_augmented(node, root, augment); + if (rebalance) + __rb_erase_color(rebalance, root, augment->rotate); +} + +#ifdef __cplusplus +} +#endif + +#endif /* _LINUX_RBTREE_AUGMENTED_H */ |