linux/block/elevator.c, branch v4.19

block: fix deadline elevator drain for zoned block devices

2018-09-27T01:57:24Z

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. Signed-off-by: Damien Le Moal Fixes: 8dc8146f9c92 ("deadline-iosched: Introduce zone locking support") Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe

block: remove unnecessary condition check

2018-08-28T01:16:06Z

kmem_cache_destroy() can handle NULL pointer correctly, so there is no need to check e->icq_cache before calling kmem_cache_destroy(). Signed-off-by: Chengguang Xu Signed-off-by: Jens Axboe

blk-mq: init hctx sched after update ctx and hctx mapping

2018-08-21T15:02:55Z

Currently, when update nr_hw_queues, IO scheduler's init_hctx will be invoked before the mapping between ctx and hctx is adapted correctly by blk_mq_map_swqueue. The IO scheduler init_hctx (kyber) may depend on this mapping and get wrong result and panic finally. A simply way to fix this is that switch the IO scheduler to 'none' before update the nr_hw_queues, and then switch it back after update nr_hw_queues. blk_mq_sched_init_/exit_hctx are removed due to nobody use them any more. Signed-off-by: Jianchao Wang Signed-off-by: Jens Axboe

block: split the blk-mq case from elevator_init

2018-06-01T13:38:21Z

There is almost no shared logic, which leads to a very confusing code flow. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jens Axboe

block: move sysfs_lock into elevator_init

2018-06-01T13:38:19Z

Both callers take just around so function call, so move it in. Also remove the now pointless blk_mq_sched_init wrapper. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jens Axboe

block: remove the always unused name argument to elevator_init

2018-06-01T13:38:17Z

Reported-by: Damien Le Moal Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jens Axboe

block: unexport elevator_init/exit

2018-06-01T13:38:16Z

These are only used by the block core. Also move the declarations to block/blk.h. Reported-by: Damien Le Moal Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jens Axboe

block: move initialization of elevator-related fields to blk_alloc_queue_node

2018-06-01T13:38:14Z

No point in doing this in elevator_init. Signed-off-by: Christoph Hellwig Reported-by: Damien Le Moal Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Jens Axboe

block: Document scheduler modification locking requirements

2018-01-18T19:54:42Z

This patch does not change any functionality. Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe

block: Unexport elv_register_queue() and elv_unregister_queue()

2018-01-18T19:54:41Z

These two functions are only called from inside the block layer so unexport them. Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe