btrfs: inline checksum name and driver definitions

There's an unnecessary indirection in the checksum definition table,
pointer and the string itself. The strings are short and the overall
size of one entry is now 24 bytes.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index f948435..bfedbbe 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -31,8 +31,8 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path,
 
 static const struct btrfs_csums {
        u16             size;
-       const char      *name;
-       const char      *driver;
+       const char      name[10];
+       const char      driver[12];
 } btrfs_csums[] = {
        [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
        [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" },
@@ -63,7 +63,8 @@ const char *btrfs_super_csum_name(u16 csum_type)
 const char *btrfs_super_csum_driver(u16 csum_type)
 {
        /* csum type is validated at mount time */
-       return btrfs_csums[csum_type].driver ?:
+       return btrfs_csums[csum_type].driver[0] ?
+               btrfs_csums[csum_type].driver :
                btrfs_csums[csum_type].name;
 }