1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
6 #include <asm/unaligned.h>
11 static bool check_setget_bounds(const struct extent_buffer *eb,
12 const void *ptr, unsigned off, int size)
14 const unsigned long member_offset = (unsigned long)ptr + off;
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);
27 void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb)
30 token->kaddr = folio_address(eb->folios[0]);
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.
40 * - btrfs_set_8 (for 8/16/32/64)
41 * - btrfs_get_8 (for 8/16/32/64)
43 * Generic helpers with a token (cached address of the most recently accessed
45 * - btrfs_set_token_8 (for 8/16/32/64)
46 * - btrfs_get_token_8 (for 8/16/32/64)
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.
53 * The extent buffer pages stored in the array folios may 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.
58 #define DEFINE_BTRFS_SETGET_BITS(bits) \
59 u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \
60 const void *ptr, unsigned long off) \
62 const unsigned long member_offset = (unsigned long)ptr + off; \
63 const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \
64 const unsigned long oil = get_eb_offset_in_folio(token->eb, \
66 const int unit_size = folio_size(token->eb->folios[0]); \
67 const int unit_shift = folio_shift(token->eb->folios[0]); \
68 const int size = sizeof(u##bits); \
69 u8 lebytes[sizeof(u##bits)]; \
70 const int part = unit_size - oil; \
73 ASSERT(token->kaddr); \
74 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
75 if (token->offset <= member_offset && \
76 member_offset + size <= token->offset + unit_size) { \
77 return get_unaligned_le##bits(token->kaddr + oil); \
79 token->kaddr = folio_address(token->eb->folios[idx]); \
80 token->offset = idx << unit_shift; \
81 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \
82 return get_unaligned_le##bits(token->kaddr + oil); \
84 memcpy(lebytes, token->kaddr + oil, part); \
85 token->kaddr = folio_address(token->eb->folios[idx + 1]); \
86 token->offset = (idx + 1) << unit_shift; \
87 memcpy(lebytes + part, token->kaddr, size - part); \
88 return get_unaligned_le##bits(lebytes); \
90 u##bits btrfs_get_##bits(const struct extent_buffer *eb, \
91 const void *ptr, unsigned long off) \
93 const unsigned long member_offset = (unsigned long)ptr + off; \
94 const unsigned long idx = get_eb_folio_index(eb, member_offset);\
95 const unsigned long oil = get_eb_offset_in_folio(eb, \
97 const int unit_size = folio_size(eb->folios[0]); \
98 char *kaddr = folio_address(eb->folios[idx]); \
99 const int size = sizeof(u##bits); \
100 const int part = unit_size - oil; \
101 u8 lebytes[sizeof(u##bits)]; \
103 ASSERT(check_setget_bounds(eb, ptr, off, size)); \
104 if (INLINE_EXTENT_BUFFER_PAGES == 1 || oil + size <= unit_size) \
105 return get_unaligned_le##bits(kaddr + oil); \
107 memcpy(lebytes, kaddr + oil, part); \
108 kaddr = folio_address(eb->folios[idx + 1]); \
109 memcpy(lebytes + part, kaddr, size - part); \
110 return get_unaligned_le##bits(lebytes); \
112 void btrfs_set_token_##bits(struct btrfs_map_token *token, \
113 const void *ptr, unsigned long off, \
116 const unsigned long member_offset = (unsigned long)ptr + off; \
117 const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \
118 const unsigned long oil = get_eb_offset_in_folio(token->eb, \
120 const int unit_size = folio_size(token->eb->folios[0]); \
121 const int unit_shift = folio_shift(token->eb->folios[0]); \
122 const int size = sizeof(u##bits); \
123 u8 lebytes[sizeof(u##bits)]; \
124 const int part = unit_size - oil; \
127 ASSERT(token->kaddr); \
128 ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \
129 if (token->offset <= member_offset && \
130 member_offset + size <= token->offset + unit_size) { \
131 put_unaligned_le##bits(val, token->kaddr + oil); \
134 token->kaddr = folio_address(token->eb->folios[idx]); \
135 token->offset = idx << unit_shift; \
136 if (INLINE_EXTENT_BUFFER_PAGES == 1 || \
137 oil + size <= unit_size) { \
138 put_unaligned_le##bits(val, token->kaddr + oil); \
141 put_unaligned_le##bits(val, lebytes); \
142 memcpy(token->kaddr + oil, lebytes, part); \
143 token->kaddr = folio_address(token->eb->folios[idx + 1]); \
144 token->offset = (idx + 1) << unit_shift; \
145 memcpy(token->kaddr, lebytes + part, size - part); \
147 void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \
148 unsigned long off, u##bits val) \
150 const unsigned long member_offset = (unsigned long)ptr + off; \
151 const unsigned long idx = get_eb_folio_index(eb, member_offset);\
152 const unsigned long oil = get_eb_offset_in_folio(eb, \
154 const int unit_size = folio_size(eb->folios[0]); \
155 char *kaddr = folio_address(eb->folios[idx]); \
156 const int size = sizeof(u##bits); \
157 const int part = unit_size - oil; \
158 u8 lebytes[sizeof(u##bits)]; \
160 ASSERT(check_setget_bounds(eb, ptr, off, size)); \
161 if (INLINE_EXTENT_BUFFER_PAGES == 1 || \
162 oil + size <= unit_size) { \
163 put_unaligned_le##bits(val, kaddr + oil); \
167 put_unaligned_le##bits(val, lebytes); \
168 memcpy(kaddr + oil, lebytes, part); \
169 kaddr = folio_address(eb->folios[idx + 1]); \
170 memcpy(kaddr, lebytes + part, size - part); \
173 DEFINE_BTRFS_SETGET_BITS(8)
174 DEFINE_BTRFS_SETGET_BITS(16)
175 DEFINE_BTRFS_SETGET_BITS(32)
176 DEFINE_BTRFS_SETGET_BITS(64)
178 void btrfs_node_key(const struct extent_buffer *eb,
179 struct btrfs_disk_key *disk_key, int nr)
181 unsigned long ptr = btrfs_node_key_ptr_offset(eb, nr);
182 read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
183 struct btrfs_key_ptr, key, disk_key);