btrfs: add xxhash64 to checksumming algorithms

Add xxhash64 to the list of possible checksumming algorithms used by
BTRFS.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 38651fa..6d5a01c 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -5,6 +5,7 @@
 	select CRYPTO
 	select CRYPTO_CRC32C
 	select LIBCRC32C
+	select CRYPTO_XXHASH
 	select ZLIB_INFLATE
 	select ZLIB_DEFLATE
 	select LZO_COMPRESS
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 7397579..7463c12 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -34,6 +34,7 @@ static const struct btrfs_csums {
 	const char	*name;
 } btrfs_csums[] = {
 	[BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
+	[BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" },
 };
 
 int btrfs_super_csum_size(const struct btrfs_super_block *s)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5d32deb..82a2fa7 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -352,6 +352,7 @@ static bool btrfs_supported_super_csum(u16 csum_type)
 {
 	switch (csum_type) {
 	case BTRFS_CSUM_TYPE_CRC32:
+	case BTRFS_CSUM_TYPE_XXHASH:
 		return true;
 	default:
 		return false;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d5d15a1..c91cdf12 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2462,3 +2462,4 @@ module_exit(exit_btrfs_fs)
 
 MODULE_LICENSE("GPL");
 MODULE_SOFTDEP("pre: crc32c");
+MODULE_SOFTDEP("pre: xxhash64");