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authorChristoph Hellwig <hch@lst.de>2017-11-02 21:29:51 +0300
committerJens Axboe <axboe@kernel.dk>2017-11-03 10:31:48 -0600
commitef71de8b15d891b27b8c983a9a8972b11cb4576a (patch)
tree8fd5ab57df5aa233aeb784d12a6533e696d9df51 /block/blk-core.c
parentf421e1d9ade4e1b88183e54425cf50e390d16a7f (diff)
downloadlinux-ef71de8b15d891b27b8c983a9a8972b11cb4576a.tar.bz2
block: add a blk_steal_bios helper
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> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 96aaa3a419a3..68cfe6780a9b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2769,6 +2769,27 @@ struct request *blk_fetch_request(struct request_queue *q)
}
EXPORT_SYMBOL(blk_fetch_request);
+/*
+ * Steal bios from a request and add them to a bio list.
+ * 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