Commit 45686b61 authored Mar 02, 2016 by Christoph Hellwig Committed by Jens Axboe Mar 03, 2016

nvme: fix max_segments integer truncation



The block layer uses an unsigned short for max_segments.  The way we
calculate the value for NVMe tends to generate very large 32-bit values,
which after integer truncation may lead to a zero value instead of
the desired outcome.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Jeff Lien <Jeff.Lien@hgst.com>
Tested-by: Jeff Lien <Jeff.Lien@hgst.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent da35825d

drivers/nvme/host/core.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -844,9 +844,11 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
		struct request_queue *q)
		{
		if (ctrl->max_hw_sectors) {
		u32 max_segments =
		(ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1;

		blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors);
		blk_queue_max_segments(q,
		(ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1);
		blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX));
		}
		if (ctrl->stripe_size)
		blk_queue_chunk_sectors(q, ctrl->stripe_size >> 9);