flush request isn't queueable in some drives. Add a flag to let driver notify block layer about this. We can optimize flush performance with the knowledge. Signed-off-by: Shaohua Li --- include/linux/blkdev.h | 11 +++++++++++ 1 file changed, 11 insertions(+) Index: linux/include/linux/blkdev.h =================================================================== --- linux.orig/include/linux/blkdev.h 2011-05-04 14:23:42.000000000 +0800 +++ linux/include/linux/blkdev.h 2011-05-04 14:24:40.000000000 +0800 @@ -364,6 +364,7 @@ struct request_queue * for flush operations */ unsigned int flush_flags; + unsigned int flush_not_queueable:1; unsigned int flush_pending_idx:1; unsigned int flush_running_idx:1; unsigned long flush_pending_since; @@ -549,6 +550,16 @@ static inline void blk_clear_queue_full( queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q); } +static inline void blk_set_queue_flush_queueable(struct request_queue *q, + bool queueable) +{ + q->flush_not_queueable = !queueable; +} + +static inline bool blk_queue_flush_queueable(struct request_queue *q) +{ + return !q->flush_not_queueable; +} /* * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/