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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
0f82731f CM |
2 | /* |
3 | * Copyright (C) 2007 Oracle. All rights reserved. | |
0f82731f CM |
4 | */ |
5 | ||
18077bb4 | 6 | #include <asm/unaligned.h> |
d352ac68 | 7 | |
18077bb4 LZ |
8 | #include "ctree.h" |
9 | ||
10 | static inline u8 get_unaligned_le8(const void *p) | |
11 | { | |
12 | return *(u8 *)p; | |
13 | } | |
14 | ||
15 | static inline void put_unaligned_le8(u8 val, void *p) | |
16 | { | |
17 | *(u8 *)p = val; | |
18 | } | |
19 | ||
5e394689 DS |
20 | static bool check_setget_bounds(const struct extent_buffer *eb, |
21 | const void *ptr, unsigned off, int size) | |
22 | { | |
23 | const unsigned long member_offset = (unsigned long)ptr + off; | |
24 | ||
25 | if (member_offset > eb->len) { | |
26 | btrfs_warn(eb->fs_info, | |
27 | "bad eb member start: ptr 0x%lx start %llu member offset %lu size %d", | |
28 | (unsigned long)ptr, eb->start, member_offset, size); | |
29 | return false; | |
30 | } | |
31 | if (member_offset + size > eb->len) { | |
32 | btrfs_warn(eb->fs_info, | |
33 | "bad eb member end: ptr 0x%lx start %llu member offset %lu size %d", | |
34 | (unsigned long)ptr, eb->start, member_offset, size); | |
35 | return false; | |
36 | } | |
37 | ||
38 | return true; | |
39 | } | |
40 | ||
18077bb4 LZ |
41 | /* |
42 | * this is some deeply nasty code. | |
d352ac68 CM |
43 | * |
44 | * The end result is that anyone who #includes ctree.h gets a | |
18077bb4 | 45 | * declaration for the btrfs_set_foo functions and btrfs_foo functions, |
01327610 | 46 | * which are wrappers of btrfs_set_token_#bits functions and |
18077bb4 | 47 | * btrfs_get_token_#bits functions, which are defined in this file. |
d352ac68 CM |
48 | * |
49 | * These setget functions do all the extent_buffer related mapping | |
50 | * required to efficiently read and write specific fields in the extent | |
51 | * buffers. Every pointer to metadata items in btrfs is really just | |
52 | * an unsigned long offset into the extent buffer which has been | |
53 | * cast to a specific type. This gives us all the gcc type checking. | |
54 | * | |
18077bb4 LZ |
55 | * The extent buffer api is used to do the page spanning work required to |
56 | * have a metadata blocksize different from the page size. | |
cb495113 DS |
57 | * |
58 | * There are 2 variants defined, one with a token pointer and one without. | |
d352ac68 CM |
59 | */ |
60 | ||
18077bb4 | 61 | #define DEFINE_BTRFS_SETGET_BITS(bits) \ |
cc4c13d5 DS |
62 | u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ |
63 | const void *ptr, unsigned long off) \ | |
0f82731f | 64 | { \ |
8f9da810 DS |
65 | const unsigned long member_offset = (unsigned long)ptr + off; \ |
66 | const unsigned long idx = member_offset >> PAGE_SHIFT; \ | |
67 | const unsigned long oip = offset_in_page(member_offset); \ | |
68 | const int size = sizeof(u##bits); \ | |
69 | __le##bits leres; \ | |
18077bb4 | 70 | \ |
48bc3950 | 71 | ASSERT(token); \ |
870b388d | 72 | ASSERT(token->kaddr); \ |
5e394689 | 73 | ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ |
8f9da810 DS |
74 | if (token->offset <= member_offset && \ |
75 | member_offset + size <= token->offset + PAGE_SIZE) { \ | |
76 | return get_unaligned_le##bits(token->kaddr + oip); \ | |
18077bb4 | 77 | } \ |
8f9da810 DS |
78 | if (oip + size <= PAGE_SIZE) { \ |
79 | token->kaddr = page_address(token->eb->pages[idx]); \ | |
80 | token->offset = idx << PAGE_SHIFT; \ | |
81 | return get_unaligned_le##bits(token->kaddr + oip); \ | |
18077bb4 | 82 | } \ |
8f9da810 DS |
83 | token->kaddr = page_address(token->eb->pages[idx + 1]); \ |
84 | token->offset = (idx + 1) << PAGE_SHIFT; \ | |
85 | read_extent_buffer(token->eb, &leres, member_offset, size); \ | |
86 | return le##bits##_to_cpu(leres); \ | |
0f82731f | 87 | } \ |
cb495113 DS |
88 | u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ |
89 | const void *ptr, unsigned long off) \ | |
90 | { \ | |
1441ed9b DS |
91 | const unsigned long member_offset = (unsigned long)ptr + off; \ |
92 | const unsigned long oip = offset_in_page(member_offset); \ | |
93 | const int size = sizeof(u##bits); \ | |
94 | __le##bits leres; \ | |
cb495113 | 95 | \ |
5e394689 | 96 | ASSERT(check_setget_bounds(eb, ptr, off, size)); \ |
1441ed9b DS |
97 | if (oip + size <= PAGE_SIZE) { \ |
98 | const unsigned long idx = member_offset >> PAGE_SHIFT; \ | |
99 | const char *kaddr = page_address(eb->pages[idx]); \ | |
100 | return get_unaligned_le##bits(kaddr + oip); \ | |
cb495113 | 101 | } \ |
1441ed9b DS |
102 | read_extent_buffer(eb, &leres, member_offset, size); \ |
103 | return le##bits##_to_cpu(leres); \ | |
cb495113 | 104 | } \ |
cc4c13d5 | 105 | void btrfs_set_token_##bits(struct btrfs_map_token *token, \ |
1cbb1f45 | 106 | const void *ptr, unsigned long off, \ |
cc4c13d5 | 107 | u##bits val) \ |
0f82731f | 108 | { \ |
18077bb4 LZ |
109 | unsigned long part_offset = (unsigned long)ptr; \ |
110 | unsigned long offset = part_offset + off; \ | |
111 | void *p; \ | |
112 | int err; \ | |
113 | char *kaddr; \ | |
114 | unsigned long map_start; \ | |
115 | unsigned long map_len; \ | |
116 | int size = sizeof(u##bits); \ | |
117 | \ | |
48bc3950 | 118 | ASSERT(token); \ |
870b388d | 119 | ASSERT(token->kaddr); \ |
5e394689 | 120 | ASSERT(check_setget_bounds(token->eb, ptr, off, size)); \ |
870b388d | 121 | if (token->offset <= offset && \ |
ea1754a0 | 122 | (token->offset + PAGE_SIZE >= offset + size)) { \ |
18077bb4 LZ |
123 | kaddr = token->kaddr; \ |
124 | p = kaddr + part_offset - token->offset; \ | |
125 | put_unaligned_le##bits(val, p + off); \ | |
126 | return; \ | |
127 | } \ | |
4dae666a | 128 | err = map_private_extent_buffer(token->eb, offset, size, \ |
18077bb4 LZ |
129 | &kaddr, &map_start, &map_len); \ |
130 | if (err) { \ | |
131 | __le##bits val2; \ | |
132 | \ | |
133 | val2 = cpu_to_le##bits(val); \ | |
4dae666a | 134 | write_extent_buffer(token->eb, &val2, offset, size); \ |
18077bb4 LZ |
135 | return; \ |
136 | } \ | |
137 | p = kaddr + part_offset - map_start; \ | |
138 | put_unaligned_le##bits(val, p + off); \ | |
48bc3950 DS |
139 | token->kaddr = kaddr; \ |
140 | token->offset = map_start; \ | |
cb495113 DS |
141 | } \ |
142 | void btrfs_set_##bits(struct extent_buffer *eb, void *ptr, \ | |
143 | unsigned long off, u##bits val) \ | |
144 | { \ | |
029e4a42 DS |
145 | const unsigned long member_offset = (unsigned long)ptr + off; \ |
146 | const unsigned long oip = offset_in_page(member_offset); \ | |
147 | const int size = sizeof(u##bits); \ | |
148 | __le##bits leres; \ | |
cb495113 | 149 | \ |
5e394689 | 150 | ASSERT(check_setget_bounds(eb, ptr, off, size)); \ |
029e4a42 DS |
151 | if (oip + size <= PAGE_SIZE) { \ |
152 | const unsigned long idx = member_offset >> PAGE_SHIFT; \ | |
153 | char *kaddr = page_address(eb->pages[idx]); \ | |
154 | put_unaligned_le##bits(val, kaddr + oip); \ | |
cb495113 DS |
155 | return; \ |
156 | } \ | |
029e4a42 DS |
157 | leres = cpu_to_le##bits(val); \ |
158 | write_extent_buffer(eb, &leres, member_offset, size); \ | |
18077bb4 | 159 | } |
0f82731f | 160 | |
18077bb4 LZ |
161 | DEFINE_BTRFS_SETGET_BITS(8) |
162 | DEFINE_BTRFS_SETGET_BITS(16) | |
163 | DEFINE_BTRFS_SETGET_BITS(32) | |
164 | DEFINE_BTRFS_SETGET_BITS(64) | |
0f82731f | 165 | |
1cbb1f45 | 166 | void btrfs_node_key(const struct extent_buffer *eb, |
e644d021 CM |
167 | struct btrfs_disk_key *disk_key, int nr) |
168 | { | |
169 | unsigned long ptr = btrfs_node_key_ptr_offset(nr); | |
e644d021 CM |
170 | read_eb_member(eb, (struct btrfs_key_ptr *)ptr, |
171 | struct btrfs_key_ptr, key, disk_key); | |
172 | } |