1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2007 Oracle. All rights reserved. 4 */ 5 6#include <asm/unaligned.h> 7#include "messages.h" 8#include "ctree.h" 9#include "accessors.h" 10 11static bool check_setget_bounds(const struct extent_buffer *eb, 12 const void *ptr, unsigned off, int size) 13{ 14 const unsigned long member_offset = (unsigned long)ptr + off; 15 16 if (unlikely(member_offset + size > eb->len)) { 17 btrfs_warn(eb->fs_info, 18 "bad eb member %s: ptr 0x%lx start %llu member offset %lu size %d", 19 (member_offset > eb->len ? "start" : "end"), 20 (unsigned long)ptr, eb->start, member_offset, size); 21 return false; 22 } 23 24 return true; 25} 26 27void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb) 28{ 29 token->eb = eb; 30 token->kaddr = page_address(eb->pages[0]); 31 token->offset = 0; 32} 33 34/* 35 * Macro templates that define helpers to read/write extent buffer data of a 36 * given size, that are also used via ctree.h for access to item members by 37 * specialized helpers. 38 * 39 * Generic helpers: 40 * - btrfs_set_8 (for 8/16/32/64) 41 * - btrfs_get_8 (for 8/16/32/64) 42 * 43 * Generic helpers with a token (cached address of the most recently accessed 44 * page): 45 * - btrfs_set_token_8 (for 8/16/32/64) 46 * - btrfs_get_token_8 (for 8/16/32/64) 47 * 48 * The set/get functions handle data spanning two pages transparently, in case 49 * metadata block size is larger than page. Every pointer to metadata items is 50 * an offset into the extent buffer page array, cast to a specific type. This 51 * gives us all the type checking. 52 * 53 * The extent buffer pages stored in the array pages do not form a contiguous 54 * phyusical range, but the API functions assume the linear offset to the range 55 * from 0 to metadata node size. 56 */ 57 58#define DEFINE_BTRFS_SETGET_BITS(bits) \ 59u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ 60 const void *ptr, unsigned long off) \ 61{ \ 62 const unsigned long member_offset = (unsigned long)ptr + off; \ 63 const unsigned long idx = get_eb_page_index(member_offset); \ 64 const unsigned long oip = get_eb_offset_in_page(token->eb, \ 65 member_offset); \ 66 const int size = sizeof(u##bits); \ 67 u8 lebytes[sizeof(u##bits)]; \ 68 const int part = PAGE_SIZE - oip; \ 69 \ 70 ASSERT(token); \ 71 ASSERT(token->kaddr); \ 72 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ 73 if (token->offset <= member_offset && \ 74 member_offset + size <= token->offset + PAGE_SIZE) { \ 75 return get_unaligned_le##bits(token->kaddr + oip); \ 76 } \ 77 token->kaddr = page_address(token->eb->pages[idx]); \ 78 token->offset = idx << PAGE_SHIFT; \ 79 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE ) \ 80 return get_unaligned_le##bits(token->kaddr + oip); \ 81 \ 82 memcpy(lebytes, token->kaddr + oip, part); \ 83 token->kaddr = page_address(token->eb->pages[idx + 1]); \ 84 token->offset = (idx + 1) << PAGE_SHIFT; \ 85 memcpy(lebytes + part, token->kaddr, size - part); \ 86 return get_unaligned_le##bits(lebytes); \ 87} \ 88u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ 89 const void *ptr, unsigned long off) \ 90{ \ 91 const unsigned long member_offset = (unsigned long)ptr + off; \ 92 const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ 93 const unsigned long idx = get_eb_page_index(member_offset); \ 94 char *kaddr = page_address(eb->pages[idx]); \ 95 const int size = sizeof(u##bits); \ 96 const int part = PAGE_SIZE - oip; \ 97 u8 lebytes[sizeof(u##bits)]; \ 98 \ 99 ASSERT(check_setget_bounds(eb, ptr, off, size)); \ 100 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE) \ 101 return get_unaligned_le##bits(kaddr + oip); \ 102 \ 103 memcpy(lebytes, kaddr + oip, part); \ 104 kaddr = page_address(eb->pages[idx + 1]); \ 105 memcpy(lebytes + part, kaddr, size - part); \ 106 return get_unaligned_le##bits(lebytes); \ 107} \ 108void btrfs_set_token_##bits(struct btrfs_map_token *token, \ 109 const void *ptr, unsigned long off, \ 110 u##bits val) \ 111{ \ 112 const unsigned long member_offset = (unsigned long)ptr + off; \ 113 const unsigned long idx = get_eb_page_index(member_offset); \ 114 const unsigned long oip = get_eb_offset_in_page(token->eb, \ 115 member_offset); \ 116 const int size = sizeof(u##bits); \ 117 u8 lebytes[sizeof(u##bits)]; \ 118 const int part = PAGE_SIZE - oip; \ 119 \ 120 ASSERT(token); \ 121 ASSERT(token->kaddr); \ 122 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ 123 if (token->offset <= member_offset && \ 124 member_offset + size <= token->offset + PAGE_SIZE) { \ 125 put_unaligned_le##bits(val, token->kaddr + oip); \ 126 return; \ 127 } \ 128 token->kaddr = page_address(token->eb->pages[idx]); \ 129 token->offset = idx << PAGE_SHIFT; \ 130 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE) { \ 131 put_unaligned_le##bits(val, token->kaddr + oip); \ 132 return; \ 133 } \ 134 put_unaligned_le##bits(val, lebytes); \ 135 memcpy(token->kaddr + oip, lebytes, part); \ 136 token->kaddr = page_address(token->eb->pages[idx + 1]); \ 137 token->offset = (idx + 1) << PAGE_SHIFT; \ 138 memcpy(token->kaddr, lebytes + part, size - part); \ 139} \ 140void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \ 141 unsigned long off, u##bits val) \ 142{ \ 143 const unsigned long member_offset = (unsigned long)ptr + off; \ 144 const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ 145 const unsigned long idx = get_eb_page_index(member_offset); \ 146 char *kaddr = page_address(eb->pages[idx]); \ 147 const int size = sizeof(u##bits); \ 148 const int part = PAGE_SIZE - oip; \ 149 u8 lebytes[sizeof(u##bits)]; \ 150 \ 151 ASSERT(check_setget_bounds(eb, ptr, off, size)); \ 152 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oip + size <= PAGE_SIZE) { \ 153 put_unaligned_le##bits(val, kaddr + oip); \ 154 return; \ 155 } \ 156 \ 157 put_unaligned_le##bits(val, lebytes); \ 158 memcpy(kaddr + oip, lebytes, part); \ 159 kaddr = page_address(eb->pages[idx + 1]); \ 160 memcpy(kaddr, lebytes + part, size - part); \ 161} 162 163DEFINE_BTRFS_SETGET_BITS(8) 164DEFINE_BTRFS_SETGET_BITS(16) 165DEFINE_BTRFS_SETGET_BITS(32) 166DEFINE_BTRFS_SETGET_BITS(64) 167 168void btrfs_node_key(const struct extent_buffer *eb, 169 struct btrfs_disk_key *disk_key, int nr) 170{ 171 unsigned long ptr = btrfs_node_key_ptr_offset(eb, nr); 172 read_eb_member(eb, (struct btrfs_key_ptr *)ptr, 173 struct btrfs_key_ptr, key, disk_key); 174} 175