blk-mq: allow drivers to hook into I/O completion

Split out the bottom half of blk_mq_end_io so that drivers can perform
work when they know a request has been completed, but before it has been
freed.  This also obsoletes blk_mq_end_io_partial as drivers can now
pass any value to blk_update_request directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b59a8d027dff956ec2c45b59b9f61008fb1e483c..86d66e0e900c37cf0c7f270d27db5986596b932f 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -294,20 +294,24 @@ void blk_mq_clone_flush_request(struct request *flush_rq,
                hctx->cmd_size);
 }
 
-bool blk_mq_end_io_partial(struct request *rq, int error, unsigned int nr_bytes)
+inline void __blk_mq_end_io(struct request *rq, int error)
 {
-       if (blk_update_request(rq, error, blk_rq_bytes(rq)))
-               return true;
-
        blk_account_io_done(rq);
 
        if (rq->end_io)
                rq->end_io(rq, error);
        else
                blk_mq_free_request(rq);
-       return false;
 }
-EXPORT_SYMBOL(blk_mq_end_io_partial);
+EXPORT_SYMBOL(__blk_mq_end_io);
+
+void blk_mq_end_io(struct request *rq, int error)
+{
+       if (blk_update_request(rq, error, blk_rq_bytes(rq)))
+               BUG();
+       __blk_mq_end_io(rq, error);
+}
+EXPORT_SYMBOL(blk_mq_end_io);
 
 static void __blk_mq_complete_request_remote(void *data)
 {

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a4ea0ce83b07b140ddb200763aff016354a5528a..a81b474b794fbf7a91c9fd57bc15dc0e8c0d8da1 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -149,13 +149,8 @@ struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_ind
 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 
-bool blk_mq_end_io_partial(struct request *rq, int error,
-               unsigned int nr_bytes);
-static inline void blk_mq_end_io(struct request *rq, int error)
-{
-       bool done = !blk_mq_end_io_partial(rq, error, blk_rq_bytes(rq));
-       BUG_ON(!done);
-}
+void blk_mq_end_io(struct request *rq, int error);
+void __blk_mq_end_io(struct request *rq, int error);
 
 void blk_mq_complete_request(struct request *rq);