[PATCH 04/17] block: add a blk_steal_bios helper
From: Christoph Hellwig <hch@lst.de>
Date: 2017-10-23 14:51:13
Also in:
linux-nvme
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
This helpers allows to bounce steal the uncompleted bios from a request so that they can be reissued on another path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> --- block/blk-core.c | 20 ++++++++++++++++++++ include/linux/blkdev.h | 2 ++ 2 files changed, 22 insertions(+)
diff --git a/block/blk-core.c b/block/blk-core.c
index b8c80f39f5fe..e804529e65a5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c@@ -2767,6 +2767,26 @@ struct request *blk_fetch_request(struct request_queue *q) } EXPORT_SYMBOL(blk_fetch_request); +/* + * Steal bios from a request. The request must not have been partially + * completed before. + */ +void blk_steal_bios(struct bio_list *list, struct request *rq) +{ + if (rq->bio) { + if (list->tail) + list->tail->bi_next = rq->bio; + else + list->head = rq->bio; + list->tail = rq->biotail; + } + + rq->bio = NULL; + rq->biotail = NULL; + rq->__data_len = 0; +} +EXPORT_SYMBOL_GPL(blk_steal_bios); + /** * blk_update_request - Special helper function for request stacking drivers * @req: the request being processed
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 780f01db5899..45c63764a14e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h@@ -1110,6 +1110,8 @@ extern struct request *blk_peek_request(struct request_queue *q); extern void blk_start_request(struct request *rq); extern struct request *blk_fetch_request(struct request_queue *q); +void blk_steal_bios(struct bio_list *list, struct request *rq); + /* * Request completion related functions. *
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2.14.2