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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2007 Oracle. All rights reserved.4 */5 6#include <linux/unaligned.h>7#include "messages.h"8#include "extent_io.h"9#include "fs.h"10#include "accessors.h"11 12static bool check_setget_bounds(const struct extent_buffer *eb,13 const void *ptr, unsigned off, int size)14{15 const unsigned long member_offset = (unsigned long)ptr + off;16 17 if (unlikely(member_offset + size > eb->len)) {18 btrfs_warn(eb->fs_info,19 "bad eb member %s: ptr 0x%lx start %llu member offset %lu size %d",20 (member_offset > eb->len ? "start" : "end"),21 (unsigned long)ptr, eb->start, member_offset, size);22 return false;23 }24 25 return true;26}27 28void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb)29{30 token->eb = eb;31 token->kaddr = folio_address(eb->folios[0]);32 token->offset = 0;33}34 35/*36 * Macro templates that define helpers to read/write extent buffer data of a37 * given size, that are also used via ctree.h for access to item members by38 * specialized helpers.39 *40 * Generic helpers:41 * - btrfs_set_8 (for 8/16/32/64)42 * - btrfs_get_8 (for 8/16/32/64)43 *44 * Generic helpers with a token (cached address of the most recently accessed45 * page):46 * - btrfs_set_token_8 (for 8/16/32/64)47 * - btrfs_get_token_8 (for 8/16/32/64)48 *49 * The set/get functions handle data spanning two pages transparently, in case50 * metadata block size is larger than page. Every pointer to metadata items is51 * an offset into the extent buffer page array, cast to a specific type. This52 * gives us all the type checking.53 *54 * The extent buffer pages stored in the array folios may not form a contiguous55 * phyusical range, but the API functions assume the linear offset to the range56 * from 0 to metadata node size.57 */58 59#define DEFINE_BTRFS_SETGET_BITS(bits) \60u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \61 const void *ptr, unsigned long off) \62{ \63 const unsigned long member_offset = (unsigned long)ptr + off; \64 const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \65 const unsigned long oil = get_eb_offset_in_folio(token->eb, \66 member_offset);\67 const int unit_size = token->eb->folio_size; \68 const int unit_shift = token->eb->folio_shift; \69 const int size = sizeof(u##bits); \70 u8 lebytes[sizeof(u##bits)]; \71 const int part = unit_size - oil; \72 \73 ASSERT(token); \74 ASSERT(token->kaddr); \75 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \76 if (token->offset <= member_offset && \77 member_offset + size <= token->offset + unit_size) { \78 return get_unaligned_le##bits(token->kaddr + oil); \79 } \80 token->kaddr = folio_address(token->eb->folios[idx]); \81 token->offset = idx << unit_shift; \82 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \83 return get_unaligned_le##bits(token->kaddr + oil); \84 \85 memcpy(lebytes, token->kaddr + oil, part); \86 token->kaddr = folio_address(token->eb->folios[idx + 1]); \87 token->offset = (idx + 1) << unit_shift; \88 memcpy(lebytes + part, token->kaddr, size - part); \89 return get_unaligned_le##bits(lebytes); \90} \91u##bits btrfs_get_##bits(const struct extent_buffer *eb, \92 const void *ptr, unsigned long off) \93{ \94 const unsigned long member_offset = (unsigned long)ptr + off; \95 const unsigned long idx = get_eb_folio_index(eb, member_offset);\96 const unsigned long oil = get_eb_offset_in_folio(eb, \97 member_offset);\98 const int unit_size = eb->folio_size; \99 char *kaddr = folio_address(eb->folios[idx]); \100 const int size = sizeof(u##bits); \101 const int part = unit_size - oil; \102 u8 lebytes[sizeof(u##bits)]; \103 \104 ASSERT(check_setget_bounds(eb, ptr, off, size)); \105 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \106 return get_unaligned_le##bits(kaddr + oil); \107 \108 memcpy(lebytes, kaddr + oil, part); \109 kaddr = folio_address(eb->folios[idx + 1]); \110 memcpy(lebytes + part, kaddr, size - part); \111 return get_unaligned_le##bits(lebytes); \112} \113void btrfs_set_token_##bits(struct btrfs_map_token *token, \114 const void *ptr, unsigned long off, \115 u##bits val) \116{ \117 const unsigned long member_offset = (unsigned long)ptr + off; \118 const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \119 const unsigned long oil = get_eb_offset_in_folio(token->eb, \120 member_offset);\121 const int unit_size = token->eb->folio_size; \122 const int unit_shift = token->eb->folio_shift; \123 const int size = sizeof(u##bits); \124 u8 lebytes[sizeof(u##bits)]; \125 const int part = unit_size - oil; \126 \127 ASSERT(token); \128 ASSERT(token->kaddr); \129 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \130 if (token->offset <= member_offset && \131 member_offset + size <= token->offset + unit_size) { \132 put_unaligned_le##bits(val, token->kaddr + oil); \133 return; \134 } \135 token->kaddr = folio_address(token->eb->folios[idx]); \136 token->offset = idx << unit_shift; \137 if (INLINE_EXTENT_BUFFER_PAGES == 1 || \138 oil + size <= unit_size) { \139 put_unaligned_le##bits(val, token->kaddr + oil); \140 return; \141 } \142 put_unaligned_le##bits(val, lebytes); \143 memcpy(token->kaddr + oil, lebytes, part); \144 token->kaddr = folio_address(token->eb->folios[idx + 1]); \145 token->offset = (idx + 1) << unit_shift; \146 memcpy(token->kaddr, lebytes + part, size - part); \147} \148void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \149 unsigned long off, u##bits val) \150{ \151 const unsigned long member_offset = (unsigned long)ptr + off; \152 const unsigned long idx = get_eb_folio_index(eb, member_offset);\153 const unsigned long oil = get_eb_offset_in_folio(eb, \154 member_offset);\155 const int unit_size = eb->folio_size; \156 char *kaddr = folio_address(eb->folios[idx]); \157 const int size = sizeof(u##bits); \158 const int part = unit_size - oil; \159 u8 lebytes[sizeof(u##bits)]; \160 \161 ASSERT(check_setget_bounds(eb, ptr, off, size)); \162 if (INLINE_EXTENT_BUFFER_PAGES == 1 || \163 oil + size <= unit_size) { \164 put_unaligned_le##bits(val, kaddr + oil); \165 return; \166 } \167 \168 put_unaligned_le##bits(val, lebytes); \169 memcpy(kaddr + oil, lebytes, part); \170 kaddr = folio_address(eb->folios[idx + 1]); \171 memcpy(kaddr, lebytes + part, size - part); \172}173 174DEFINE_BTRFS_SETGET_BITS(8)175DEFINE_BTRFS_SETGET_BITS(16)176DEFINE_BTRFS_SETGET_BITS(32)177DEFINE_BTRFS_SETGET_BITS(64)178 179void btrfs_node_key(const struct extent_buffer *eb,180 struct btrfs_disk_key *disk_key, int nr)181{182 unsigned long ptr = btrfs_node_key_ptr_offset(eb, nr);183 read_eb_member(eb, (struct btrfs_key_ptr *)ptr,184 struct btrfs_key_ptr, key, disk_key);185}186