Commit 403c37ff authored Dec 18, 2018 by Jaegeuk Kim Committed by Alistair Strachan Jan 23, 2019

UPSTREAM: dm: do not allow readahead to limit IO size



Update DM to set the bdi's io_pages.  This fixes reads to be capped at
the device's max request size (even if user's read IO exceeds the
established readahead setting).

Fixes: 9491ae4a ("mm: don't cap request size based on read-ahead setting")
Cc: stable@vger.kernel.org
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
(cherry picked from commit c6d6e9b0f6b4201c77f2cea3964dd122697e3543)
Bug: 120757803
Link: https://patchwork.kernel.org/patch/10746255/
Change-Id: I876f4c5425253c2a0876d5ef7fefe36c4edcb46c

parent c29a889a

drivers/md/dm-table.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -1937,6 +1937,9 @@ void dm_table_set_restrictions(struct dm_table t, struct request_queue q,
		*/
		if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);

		/* io_pages is used for readahead */
		q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
		}

		unsigned int dm_table_get_num_targets(struct dm_table *t)