Didn't allow discard request merge temporarily, as SCSI layer isn't ready for discard merge as Martin Petersen pointed out. This isn't fair for non-scsi device, but looks this is the only way I can do currently. We should have the same issue before, but maybe because discard merge is very rare case. But now raid0/10 makes the merge quite possible, so we need disable it explicitly. Signed-off-by: Shaohua Li <shli@xxxxxxxxxxxx> --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/include/linux/blkdev.h =================================================================== --- linux.orig/include/linux/blkdev.h 2012-03-14 09:20:06.787261188 +0800 +++ linux/include/linux/blkdev.h 2012-03-14 09:20:47.797261248 +0800 @@ -575,7 +575,7 @@ static inline void blk_clear_queue_full( * it already be started by driver. */ #define RQ_NOMERGE_FLAGS \ - (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA) + (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_DISCARD) #define rq_mergeable(rq) \ (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ (((rq)->cmd_flags & REQ_DISCARD) || \ -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
