From: David Sterba <dsterba@xxxxxxxx> commit c8a5f8ca9a9c7d5c5bc31d54f47ea9d86f93ed69 upstream. Per user request, print the checksum type and implementation at mount time among the messages. The checksum is user configurable and the actual crypto implementation is useful to see for performance reasons. The same information is also available after mount in /sys/fs/FSID/checksum file. Example: [25.323662] BTRFS info (device vdb): using sha256 (sha256-generic) checksum algorithm Link: https://github.com/kdave/btrfs-progs/issues/483 Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/disk-io.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2318,6 +2318,9 @@ static int btrfs_init_csum_hash(struct b fs_info->csum_shash = csum_shash; + btrfs_info(fs_info, "using %s (%s) checksum algorithm", + btrfs_super_csum_name(csum_type), + crypto_shash_driver_name(csum_shash)); return 0; }