Re: [PATCH] block: always allocate genhd->ev if check_events is implemented

[Jens Axboe <axboe@kernel.dk>]

On 2011-05-25 23:06, Tejun Heo wrote:
> 9fd097b149 (block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe
> drivers) removed DISK_EVENT_MEDIA_CHANGE from legacy/fringe block
> drivers which have inadequate ->check_events().  Combined with earlier
> change 7c88a168da (block: don't propagate unlisted DISK_EVENTs to
> userland), this enables using ->check_events() for internal processing
> while avoiding enabling in-kernel block event polling which can lead
> to infinite event loop.
> 
> Unfortunately, this made many drivers including floppy without any bit
> set in disk->events and ->async_events in which case disk_add_events()
> simply skipped allocation of disk->ev, which disables whole event
> handling.  As ->check_events() is still used during open processing
> for revalidation, this can lead to open failure.
> 
> This patch always allocates disk->ev if ->check_events is implemented.
> In the long term, it would make sense to simply include the event
> structure inline into genhd as it's now used by virtually all block
> devices.

Thanks, applied.

-- 
Jens Axboe