On Aug 19, 2019, at 12:11 PM, Guilherme G. Piccoli [off-list ref] wrote:

On 19/08/2019 15:57, Song Liu wrote:

quoted

[...] 

I was thinking, if we can set MD_BROKEN when the device fails, we can 
just test MD_BROKEN in array_state_show() (instead of iterating through 
all devices). 

Would this work?

Thanks,
Song

This could work, but will require some refactors; it'll simplify the
check for a healthy array (no need for is_missing_dev() function) but
will complicate the criteria to clear MD_BROKEN and the detection of
more members failing (we would stop the detection after the 1st failure
if we only test MD_BROKEN).

We will always need to test the GENHD_FL_UP in some code path, to be
able to show users device recovered from a failure.
Where do you suggest to test this flag?

How about we test this when we do clear_bit(Faulty..)? And maybe also in 
add_new_disk()?

Thanks,
Song