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>

1 files changed, 10 insertions, 6 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b59a8d027dff..86d66e0e900c 100644
--- 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)
 {