On 2019/7/25 5:33 PM, Johannes Thumshirn wrote:
Create a structure to encode the type and length for the known on-disk
checksums. Also add a table and a convenience macro for adding the
checksum types to the table.
This makes it easier to add new checksums later.
Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
fs/btrfs/ctree.h | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index da97ff10f421..099401f5dd47 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -82,9 +82,15 @@ struct btrfs_ref;
*/
#define BTRFS_LINK_MAX 65535U
-/* four bytes for CRC32 */
-static const int btrfs_csum_sizes[] = { 4 };
-static const char *btrfs_csum_names[] = { "crc32c" };
+#define BTRFS_CHECKSUM_TYPE(_type, _size, _name) \
+ [_type] = { .size = _size, .name = _name }
+
+static const struct btrfs_csums {
+ u16 size;
+ const char *name;
+} btrfs_csums[] = {
+ BTRFS_CHECKSUM_TYPE(BTRFS_CSUM_TYPE_CRC32, 4, "crc32c"),
+};
How about:
struct btrfs_csum {
u16 size;
const char *name;
};
static const struct btrfs_csum btrfs_csums[] = {
#define BTRFS_CHECKSUM_TYPE(_type, _size, _name) \
[_type] = { .size = _size, .name = _name }
BTRFS_CHECKSUM_TYPE(BTRFS_CSUM_TYPE_CRC32, 4, "crc32c"),
};
Since the macro BTRFS_CHECKSUM_TYPE is only used in array btrfs_csum
btrfs_csums. And this makes the struct btrfs_csum clear.
---
Su
#define BTRFS_EMPTY_DIR_SIZE 0
@@ -2373,13 +2379,13 @@ static inline int btrfs_super_csum_size(const struct btrfs_super_block *s)
/*
* csum type is validated at mount time
*/
- return btrfs_csum_sizes[t];
+ return btrfs_csums[t].size;
}
static inline const char *btrfs_super_csum_name(u16 csum_type)
{
/* csum type is validated at mount time */
- return btrfs_csum_names[csum_type];
+ return btrfs_csums[csum_type].name;
}
/*
