From 2fb98e8414c42cb14698833aac640b143b9ade4f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 19 Feb 2008 11:36:53 +0100 Subject: block: implement request_queue->dma_drain_needed Draining shouldn't be done for commands where overflow may indicate data integrity issues. Add dma_drain_needed callback to request_queue. Drain buffer is appened iff this function returns non-zero. Signed-off-by: Tejun Heo Cc: James Bottomley Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f1fe9fbf1c0..6fe67d1939c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -259,6 +259,7 @@ struct bio_vec; typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *); typedef void (prepare_flush_fn) (struct request_queue *, struct request *); typedef void (softirq_done_fn)(struct request *); +typedef int (dma_drain_needed_fn)(struct request *); enum blk_queue_state { Queue_down, @@ -295,6 +296,7 @@ struct request_queue merge_bvec_fn *merge_bvec_fn; prepare_flush_fn *prepare_flush_fn; softirq_done_fn *softirq_done_fn; + dma_drain_needed_fn *dma_drain_needed; /* * Dispatch queue sorting @@ -699,8 +701,9 @@ extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short); extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); -extern int blk_queue_dma_drain(struct request_queue *q, void *buf, - unsigned int size); +extern int blk_queue_dma_drain(struct request_queue *q, + dma_drain_needed_fn *dma_drain_needed, + void *buf, unsigned int size); extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); -- cgit v1.2.3