fs/btrfs/accessors.c

28 void btrfs_init_map_token(struct btrfs_map_token *token, struct extent_buffer *eb)
30 	token->eb = eb;
31 	token->kaddr = folio_address(eb->folios[0]);
32 	token->offset = 0;
44  * Generic helpers with a token (cached address of the most recently accessed
60 u##bits btrfs_get_token_##bits(struct btrfs_map_token *token,		\
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,	\
67 	const int unit_size = token->eb->folio_size;			\
68 	const int unit_shift = token->eb->folio_shift;			\
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);	\
80 	token->kaddr = folio_address(token->eb->folios[idx]);		\
81 	token->offset = idx << unit_shift;				\
83 		return get_unaligned_le##bits(token->kaddr + oil);	\
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);		\
113 void btrfs_set_token_##bits(struct btrfs_map_token *token,		\
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,	\
121 	const int unit_size = token->eb->folio_size;			\
122 	const int unit_shift = token->eb->folio_shift;			\
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);	\
135 	token->kaddr = folio_address(token->eb->folios[idx]);		\
136 	token->offset = idx << unit_shift;				\
139 		put_unaligned_le##bits(val, token->kaddr + oil);	\
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);		\