On 2021/9/17 19:24, Qu Wenruo wrote:

On 2021/9/17 19:19, David Sterba wrote:

quoted

On Wed, Sep 15, 2021 at 03:17:16PM +0800, Qu Wenruo wrote:

quoted

The structure btrfs_bio is used by two different sites:

- bio->bi_private for mirror based profiles
   For those profiles (SINGLE/DUP/RAID1*/RAID10), this structures 
records

Why is SINGLE here?

For single we use the same routine as RAID1/DUP/etc, it's
submit_stripe_bio() doing the remapping.

Thus there is really only two types, non-RAID56 and RAID56.

And there is no really "SINGLE" profile in btrfs.

As even for SINGLE profile, we may need to submit two bios to two 
different devices (one is the current device, the other is the 
dev-replace target).

Thanks,
Qu

Thanks,
Qu