From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konstantin Khlebnikov Subject: [PATCH] block: keep bdi->io_pages in sync with max_sectors_kb for stacked devices Date: Fri, 28 Feb 2020 17:51:48 +0300 Message-ID: <158290150891.4423.13566449569964563258.stgit@buzz> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-block-owner@vger.kernel.org To: linux-block@vger.kernel.org, Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org, Song Liu , Dmitry Monakhov List-Id: linux-raid.ids Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting") removes unneeded split of read requests. Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they setup limits of their devices by blk_set_stacking_limits() + disk_stack_limits(). Field bio->io_pages stays zero until user set max_sectors_kb via sysfs. This patch updates io_pages after merging limits in disk_stack_limits(). Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed the same problem for device-mapper devices, this one fixes MD RAIDs. Signed-off-by: Konstantin Khlebnikov --- block/blk-settings.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-settings.c b/block/blk-settings.c index c8eda2e7b91e..66c45fd79545 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -664,6 +664,8 @@ void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", top, bottom); } + + t->backing_dev_info->io_pages = t->limits.max_sectors >> (PAGE_SHIFT-9); } EXPORT_SYMBOL(disk_stack_limits);