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 | |
11 | static 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 | |
27 | void 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) \ |
59 | u##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 | } \ |
88 | u##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 | } \ |
108 | void 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 | } \ |
140 | void 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 | |
163 | DEFINE_BTRFS_SETGET_BITS(8) |
164 | DEFINE_BTRFS_SETGET_BITS(16) |
165 | DEFINE_BTRFS_SETGET_BITS(32) |
166 | DEFINE_BTRFS_SETGET_BITS(64) |
167 | |
168 | void 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 | |