diff options
| -rw-r--r-- | block/blk-merge.c | 25 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 10 |
2 files changed, 21 insertions, 14 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 99c9759f3a8a..ee618cdb141e 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -519,24 +519,23 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio, * map a request to scatterlist, return number of sg entries setup. Caller * must make sure sg can hold rq->nr_phys_segments entries */ -int blk_rq_map_sg(struct request_queue *q, struct request *rq, - struct scatterlist *sglist) +int __blk_rq_map_sg(struct request_queue *q, struct request *rq, + struct scatterlist *sglist, struct scatterlist **last_sg) { - struct scatterlist *sg = NULL; int nsegs = 0; if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) - nsegs = __blk_bvec_map_sg(rq->special_vec, sglist, &sg); + nsegs = __blk_bvec_map_sg(rq->special_vec, sglist, last_sg); else if (rq->bio && bio_op(rq->bio) == REQ_OP_WRITE_SAME) - nsegs = __blk_bvec_map_sg(bio_iovec(rq->bio), sglist, &sg); + nsegs = __blk_bvec_map_sg(bio_iovec(rq->bio), sglist, last_sg); else if (rq->bio) - nsegs = __blk_bios_map_sg(q, rq->bio, sglist, &sg); + nsegs = __blk_bios_map_sg(q, rq->bio, sglist, last_sg); if (blk_rq_bytes(rq) && (blk_rq_bytes(rq) & q->dma_pad_mask)) { unsigned int pad_len = (q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1; - sg->length += pad_len; + (*last_sg)->length += pad_len; rq->extra_len += pad_len; } @@ -544,9 +543,9 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, if (op_is_write(req_op(rq))) memset(q->dma_drain_buffer, 0, q->dma_drain_size); - sg_unmark_end(sg); - sg = sg_next(sg); - sg_set_page(sg, virt_to_page(q->dma_drain_buffer), + sg_unmark_end(*last_sg); + *last_sg = sg_next(*last_sg); + sg_set_page(*last_sg, virt_to_page(q->dma_drain_buffer), q->dma_drain_size, ((unsigned long)q->dma_drain_buffer) & (PAGE_SIZE - 1)); @@ -554,8 +553,8 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, rq->extra_len += q->dma_drain_size; } - if (sg) - sg_mark_end(sg); + if (*last_sg) + sg_mark_end(*last_sg); /* * Something must have been wrong if the figured number of @@ -565,7 +564,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, return nsegs; } -EXPORT_SYMBOL(blk_rq_map_sg); +EXPORT_SYMBOL(__blk_rq_map_sg); static inline int ll_new_hw_segment(struct request *req, struct bio *bio, unsigned int nr_phys_segs) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 76da162b6ae9..496dc9491026 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1136,7 +1136,15 @@ static inline unsigned short blk_rq_nr_discard_segments(struct request *rq) return max_t(unsigned short, rq->nr_phys_segments, 1); } -extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); +int __blk_rq_map_sg(struct request_queue *q, struct request *rq, + struct scatterlist *sglist, struct scatterlist **last_sg); +static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq, + struct scatterlist *sglist) +{ + struct scatterlist *last_sg = NULL; + + return __blk_rq_map_sg(q, rq, sglist, &last_sg); +} extern void blk_dump_rq_flags(struct request *, char *); extern long nr_blockdev_pages(void); |