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 "extent_io.h" |
9 | #include "fs.h" |
10 | #include "accessors.h" |
11 | |
12 | static 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 | |
28 | void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb) |
29 | { |
30 | token->eb = eb; |
31 | token->kaddr = folio_address(folio: eb->folios[0]); |
32 | token->offset = 0; |
33 | } |
34 | |
35 | /* |
36 | * Macro templates that define helpers to read/write extent buffer data of a |
37 | * given size, that are also used via ctree.h for access to item members by |
38 | * 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 accessed |
45 | * 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 case |
50 | * metadata block size is larger than page. Every pointer to metadata items is |
51 | * an offset into the extent buffer page array, cast to a specific type. This |
52 | * gives us all the type checking. |
53 | * |
54 | * The extent buffer pages stored in the array folios may not form a contiguous |
55 | * phyusical range, but the API functions assume the linear offset to the range |
56 | * from 0 to metadata node size. |
57 | */ |
58 | |
59 | #define DEFINE_BTRFS_SETGET_BITS(bits) \ |
60 | u##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 | } \ |
91 | u##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 | } \ |
113 | void 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 | } \ |
148 | void 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 | |
174 | DEFINE_BTRFS_SETGET_BITS(8) |
175 | DEFINE_BTRFS_SETGET_BITS(16) |
176 | DEFINE_BTRFS_SETGET_BITS(32) |
177 | DEFINE_BTRFS_SETGET_BITS(64) |
178 | |
179 | void 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 | |