btrfs: struct-funcs, constify readers
We have reader helpers for most of the on-disk structures that use
an extent_buffer and pointer as offset into the buffer that are
read-only. We should mark them as const and, in turn, allow consumers
of these interfaces to mark the buffers const as well.
No impact on code, but serves as documentation that a buffer is intended
not to be modified.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index 875c757..5e2b92d 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -50,8 +50,8 @@ static inline void put_unaligned_le8(u8 val, void *p)
*/
#define DEFINE_BTRFS_SETGET_BITS(bits) \
-u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr, \
- unsigned long off, \
+u##bits btrfs_get_token_##bits(const struct extent_buffer *eb, \
+ const void *ptr, unsigned long off, \
struct btrfs_map_token *token) \
{ \
unsigned long part_offset = (unsigned long)ptr; \
@@ -90,7 +90,8 @@ u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr, \
return res; \
} \
void btrfs_set_token_##bits(struct extent_buffer *eb, \
- void *ptr, unsigned long off, u##bits val, \
+ const void *ptr, unsigned long off, \
+ u##bits val, \
struct btrfs_map_token *token) \
{ \
unsigned long part_offset = (unsigned long)ptr; \
@@ -133,7 +134,7 @@ DEFINE_BTRFS_SETGET_BITS(16)
DEFINE_BTRFS_SETGET_BITS(32)
DEFINE_BTRFS_SETGET_BITS(64)
-void btrfs_node_key(struct extent_buffer *eb,
+void btrfs_node_key(const struct extent_buffer *eb,
struct btrfs_disk_key *disk_key, int nr)
{
unsigned long ptr = btrfs_node_key_ptr_offset(nr);