On 9/26/18 7:55 PM, Damien Le Moal wrote:
When the deadline scheduler is used with a zoned block device, writes to a zone will be dispatched one at a time. This causes the warning message:
deadline: forced dispatching is broken (nr_sorted=X), please report this
to be displayed when switching to another elevator with the legacy I/O path while write requests to a zone are being retained in the scheduler queue.
Prevent this message from being displayed when executing elv_drain_elevator() for a zoned block device. __blk_drain_queue() will loop until all writes are dispatched and completed, resulting in the desired elevator queue drain without extensive modifications to the deadline code itself to handle forced-dispatch calls.
Dropped the previous one and added this one.