From d0c3914ffbe4c00f0a131bae83f811d5606699bc Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Tue, 18 Dec 2018 05:43:41 -0800 Subject: [PATCH] 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 Signed-off-by: Jaegeuk Kim Signed-off-by: Mike Snitzer (cherry picked from commit c6d6e9b0f6b4201c77f2cea3964dd122697e3543) Bug: 120757803 Link: https://patchwork.kernel.org/patch/10746255/ Change-Id: I876f4c5425253c2a0876d5ef7fefe36c4edcb46c --- drivers/md/dm-table.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 33b4afc6a687..a37bdf6cd66f 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1542,6 +1542,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, smp_mb(); if (dm_table_request_based(t)) queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, 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)