block: don't allow enabling a cache on devices that don't support it

Browse source

Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.

Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.

Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.

Fixes: 93e9d8e836 ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

...

This commit is contained in:

Christoph Hellwig 2023-07-07 11:42:39 +02:00 • committed by Jens Axboe

parent c4e21bcd0f

commit 43c9835b14

3 changed files with 13 additions and 6 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

7

block/blk-settings.c

View file

11

block/blk-sysfs.c

View file

1

include/linux/blkdev.h

View file