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Ming Lei authored
In case of block device backend, if the backend supports write zeros, the loop device will set queue flag of QUEUE_FLAG_DISCARD. However, limits.discard_granularity isn't setup, and this way is wrong, see the following description in Documentation/ABI/testing/sysfs-block: A discard_granularity of 0 means that the device does not support discard functionality. Especially 9b15d109 ("block: improve discard bio alignment in __blkdev_issue_discard()") starts to take q->limits.discard_granularity for computing max discard sectors. And zero discard granularity may cause kernel oops, or fail discard request even though the loop queue claims discard support via QUEUE_FLAG_DISCARD. Fix the issue by setup discard granularity and alignment. Fixes: c52abf56 ("loop: Better discard support for block devices") Signed-off-by:
Ming Lei <ming.lei@redhat.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Acked-by:
Coly Li <colyli@suse.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Xiao Ni <xni@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Evan Green <evgreen@chromium.org> Cc: Gwendal Grignou <gwendal@chromium.org> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
bcb21c8c