From 66cb45aa41315d1d9972cada354fbdf7870d7714 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 24 Jun 2014 16:22:24 -0600 Subject: block: add support for limiting gaps in SG lists Another restriction inherited for NVMe - those devices don't support SG lists that have "gaps" in them. Gaps refers to cases where the previous SG entry doesn't end on a page boundary. For NVMe, all SG entries must start at offset 0 (except the first) and end on a page boundary (except the last). Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 713f8b62b435..8699bcf5f099 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -512,6 +512,7 @@ struct request_queue { #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ +#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ -- cgit v1.2.3-59-g8ed1b