[PATCH 23/27] block: add a bdev_max_discard_sectors helper

[David Sterba]

On Wed, Apr 06, 2022 at 08:05:12AM +0200, Christoph Hellwig wrote:
> Add a helper to query the number of sectors support per each discard bio
> based on the block device and use this helper to stop various places from
> poking into the request_queue to see if discard is supported and if so how
> much.  This mirrors what is done e.g. for write zeroes as well.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  block/blk-core.c                    |  2 +-
>  block/blk-lib.c                     |  2 +-
>  block/ioctl.c                       |  3 +--
>  drivers/block/drbd/drbd_main.c      |  2 +-
>  drivers/block/drbd/drbd_nl.c        | 12 +++++++-----
>  drivers/block/drbd/drbd_receiver.c  |  5 ++---
>  drivers/block/loop.c                |  9 +++------
>  drivers/block/rnbd/rnbd-srv-dev.h   |  6 +-----
>  drivers/block/xen-blkback/xenbus.c  |  2 +-
>  drivers/md/bcache/request.c         |  4 ++--
>  drivers/md/bcache/super.c           |  2 +-
>  drivers/md/bcache/sysfs.c           |  2 +-
>  drivers/md/dm-cache-target.c        |  9 +--------
>  drivers/md/dm-clone-target.c        |  9 +--------
>  drivers/md/dm-io.c                  |  2 +-
>  drivers/md/dm-log-writes.c          |  3 +--
>  drivers/md/dm-raid.c                |  9 ++-------
>  drivers/md/dm-table.c               |  4 +---
>  drivers/md/dm-thin.c                |  9 +--------
>  drivers/md/dm.c                     |  2 +-
>  drivers/md/md-linear.c              |  4 ++--
>  drivers/md/raid0.c                  |  2 +-
>  drivers/md/raid1.c                  |  6 +++---
>  drivers/md/raid10.c                 |  8 ++++----
>  drivers/md/raid5-cache.c            |  2 +-
>  drivers/target/target_core_device.c |  8 +++-----

For

>  fs/btrfs/extent-tree.c              |  4 ++--
>  fs/btrfs/ioctl.c                    |  2 +-

Acked-by: David Sterba <dsterba at suse.com>