From 09324d32d2a0843e66652a087da6f77924358e62 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 21 May 2019 09:01:41 +0200 Subject: block: force an unlimited segment size on queues with a virt boundary We currently fail to update the front/back segment size in the bio when deciding to allow an otherwise gappy segement to a device with a virt boundary. The reason why this did not cause problems is that devices with a virt boundary fundamentally don't use segments as we know it and thus don't care. Make that assumption formal by forcing an unlimited segement size in this case. Fixes: f6970f83ef79 ("block: don't check if adjacent bvecs in one bio can be mergeable") Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/blk-settings.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'block') diff --git a/block/blk-settings.c b/block/blk-settings.c index 3facc41476be..2ae348c101a0 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -310,6 +310,9 @@ void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) __func__, max_size); } + /* see blk_queue_virt_boundary() for the explanation */ + WARN_ON_ONCE(q->limits.virt_boundary_mask); + q->limits.max_segment_size = max_size; } EXPORT_SYMBOL(blk_queue_max_segment_size); @@ -742,6 +745,14 @@ EXPORT_SYMBOL(blk_queue_segment_boundary); void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) { q->limits.virt_boundary_mask = mask; + + /* + * Devices that require a virtual boundary do not support scatter/gather + * I/O natively, but instead require a descriptor list entry for each + * page (which might not be idential to the Linux PAGE_SIZE). Because + * of that they are not limited by our notion of "segment size". + */ + q->limits.max_segment_size = UINT_MAX; } EXPORT_SYMBOL(blk_queue_virt_boundary); -- cgit