Re: FW: change in disk failure policy for non-BBL arrays?

[Artur Paszkiewicz <artur.paszkiewicz@intel.com>]

On 11/03/2017 08:58 PM, Chris Walker wrote:
> Hello,
> I was looking at this again today and it appears that with this change, error handling no longer works correctly in RAID10 (I haven't checked the other levels yet).  Without a BBL configured, an error cycles through fix_read_error until max_read_errors is exceeded, and only then is the drive kicked out of the array.  For example, if I inject errors in response to both read and write commands at sector 16392 of /dev/sda, logs in response to a read of the corresponding md0 sector look like:
>  
> (many repeats)
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: unable to read back corrected sectors (8 sectors at 16392 on sda)
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: sda: failing drive
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: read correction write failed (8 sectors at 16392 on sda)
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: sda: failing drive
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: unable to read back corrected sectors (8 sectors at 16392 on sda)
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: sda: failing drive
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: sda: Raid device exceeded read_error threshold [cur 21:max 20]
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: sda: Failing raid device
> Oct 27 16:15:16 c1 kernel: md/raid10:md0: Disk failure on sda, disabling device.
> 
> Previously, the drive would have been failed out of the array by the call of md_error at the end of r10_sync_page_io.
> 
> Is there an appetite for a patch that takes the easy way out by reverting to the previous behavior with changes like
> 
> -       if (!rdev_set_badblocks(rdev, sector, sectors, 0))
> +       if (!rdev_set_badblocks(rdev, sector, sectors, 0) || rdev->badblocks.shift < 0)

Hi,

Some time ago I sent a patch that fixed this issue but now I see that it
never got applied:
https://marc.info/?l=linux-block&m=145986120124345&w=2. I'll resend it
and hopefully it gets applied this time.

Thanks,
Artur