Re: [PATCH 5/8] btrfs: Increment device corruption error in case of checksum error

[Josef Bacik <josef@toxicpanda.com>]

On 7/2/20 8:23 AM, Nikolay Borisov wrote:
> Now that btrfs_io_bio have access to btrfs_device we can safely
> increment the device corruption counter on error. There is one notable
> exception - repair bios for raid. Since those don't go through the
> normal submit_stripe_bio callpath but through raid56_parity_recover thus
> repair bios won't have their device set.
> 
> Link: https://lore.kernel.org/linux-btrfs/4857863.FCrPRfMyHP@liv/
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>   fs/btrfs/inode.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index e7600b0fd9b5..c6824d0ce59d 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2822,6 +2822,9 @@ static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio,
>   zeroit:
>   	btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
>   				    io_bio->mirror_num);
> +	if (io_bio->dev)
> +		btrfs_dev_stat_inc_and_print(io_bio->dev,
> +					     BTRFS_DEV_STAT_CORRUPTION_ERRS);
>   	memset(kaddr + pgoff, 1, len);
>   	flush_dcache_page(page);
>   	kunmap_atomic(kaddr);
> --
> 2.17.1
> 

I had to go look this up to see if we were double counting, but no, we only do 
BTRFS_DEV_STAT_CORRUPTION_ERRS for data with scrub, which goes through a 
different IO path than the normal reads.  Just in case anybody else is as 
confused as I was

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef