Re: [PATCH 04/17] block: add a blk_steal_bios helper
From: Max Gurtovoy <hidden>
Date: 2017-10-24 08:44:26
Also in:
linux-nvme
On 10/23/2017 5:51 PM, Christoph Hellwig wrote:
quoted hunk ↗ jump to hunk
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. + */
Maybe we can add to the comment that "list" is the destination for the stolen bio.
+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;if list->tail != NULL don't we lose the "list->tail->bi_next = rq->bio;" assignment after assigning "list->tail = rq->biotail;" ?
+ } + + rq->bio = NULL;
we can add this NULL assignment inside the big "if", but I'm not sure regarding the next 2 assignments. Anyway not a big deal.
+ rq->biotail = NULL; + rq->__data_len = 0; +} +EXPORT_SYMBOL_GPL(blk_steal_bios); +