On Sat, Feb 27, 2021 at 10:07:02PM +0200, Dāvis Mosāns wrote:
> Currently only single checksum byte is outputted.
> This fixes it so that full checksum is outputted.
Thanks, that really needs fixing.
> Signed-off-by: Dāvis Mosāns <davis...@gmail.com>
> ---
> kernel-shared/disk-io.c | 47 ++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 42 insertions(+), 5 deletions(-)
>
> diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
> index 6f584986..8773eed7 100644
> --- a/kernel-shared/disk-io.c
> +++ b/kernel-shared/disk-io.c
> @@ -160,10 +160,45 @@ int btrfs_csum_data(u16 csum_type, const u8 *data, u8
> *out, size_t len)
> return -1;
> }
>
> +int btrfs_format_csum(u16 csum_type, const char *data, char *output)
> +{
> + int i;
> + int csum_len = 0;
> + int position = 0;
> + int direction = 1;
> + switch (csum_type) {
> + case BTRFS_CSUM_TYPE_CRC32:
> + csum_len = 4;
This duplicates the per-csum size, you could use btrfs_csum_type_size
> + position = csum_len - 1;
> + direction = -1;
> + break;
> + case BTRFS_CSUM_TYPE_XXHASH:
> + csum_len = 8;
> + position = csum_len - 1;
> + direction = -1;
So the direction says if it's big endian or little endian, right, so for
xxhash it's bigendian but the crc32c above it's little.
In kernel the format is 0x%*phN, which translates to 'hexadecimal with
variable length', so all the work is hidden inside printk. But still
there are no changes in the 'direction'.
I haven't actually checked if the printed format matches what kernel
does but would think that there should be no direction adjustment
needed.
> + break;
> + case BTRFS_CSUM_TYPE_SHA256:
> + case BTRFS_CSUM_TYPE_BLAKE2:
> + csum_len = 32;
> + break;
> + default:
> + fprintf(stderr, "ERROR: unknown csum type: %d\n",
> csum_type);
> + ASSERT(0);
> + }
> +
> + for (i = 0; i < csum_len; i++) {
> + sprintf(output + i*2, "%02X", data[position + i*direction] &
> 0xFF);
> + }
> +
> + return csum_len;
> +}
> +
> static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
> int verify, int silent, u16 csum_type)
> {
> u8 result[BTRFS_CSUM_SIZE];
> + char found[BTRFS_CSUM_SIZE * 2 + 1]; // 2 hex chars for each byte + null
> + char expected[BTRFS_CSUM_SIZE * 2 + 1];
> u32 len;
>
> len = buf->len - BTRFS_CSUM_SIZE;
> @@ -172,12 +207,14 @@ static int __csum_tree_block_size(struct extent_buffer
> *buf, u16 csum_size,
>
> if (verify) {
> if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
> - /* FIXME: format */
> - if (!silent)
> - printk("checksum verify failed on %llu found
> %08X wanted %08X\n",
> + if (!silent) {
> + btrfs_format_csum(csum_type, (char *)result,
> found);
> + btrfs_format_csum(csum_type, buf->data,
> expected);
> + printk("checksum verify failed on %llu found %s
> wanted %s\n",
> (unsigned long long)buf->start,
> - result[0],
> - buf->data[0]);
> + found,
> + expected);
> + }
> return 1;
> }
> } else {
> --
> 2.30.1
