path: root/block
diff options
authorChristoph Hellwig <hch@lst.de>2019-05-21 07:01:41 (GMT)
committerJens Axboe <axboe@kernel.dk>2019-05-23 16:25:26 (GMT)
commit09324d32d2a0843e66652a087da6f77924358e62 (patch)
tree9d7851cb620f46b7d7564b8fe18ccd2b22f74a8a /block
parenteded341c085bebdd653f8086c02179098cb81748 (diff)
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 <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
1 files changed, 11 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 3facc41..2ae348c 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;
@@ -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;