This patch causes boot failures when using REQ_FLUSH requests. Also the
following statement in the commit log:
For non mq calls, the block layer will free the bios when
blk_finish_request is called.
For mq calls, the blk mq code wants the caller to do this.
Seems incorrect as far as I can follow the code as blk_finish_request only
calls __blk_put_request which then completes the bios if req->end_io is
not set. This matches the blk-mq behaviour before this patch, so reverting
it makes the code more similar to the legacy case in addition to fixing the
boot failure.
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
block/blk-flush.c | 2 +-
block/blk-mq.c | 14 ++++++++++----
block/blk-mq.h | 1 +
3 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 3e4cc9c..c56c37d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -231,7 +231,7 @@ static void flush_end_io(struct request *flush_rq, int
error)
unsigned long flags = 0;
if (q->mq_ops) {
- blk_mq_free_request(flush_rq);
+ blk_mq_finish_request(flush_rq, error);
spin_lock_irqsave(&q->mq_flush_lock, flags);
}
running = &q->flush_queue[q->flush_running_idx];
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 93563e0..423089d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -270,7 +270,7 @@ void blk_mq_free_request(struct request *rq)
}
EXPORT_SYMBOL(blk_mq_free_request);
-static void blk_mq_finish_request(struct request *rq, int error)
+void blk_mq_finish_request(struct request *rq, int error)
{
struct bio *bio = rq->bio;
unsigned int bytes = 0;
@@ -286,17 +286,22 @@ static void blk_mq_finish_request(struct request *rq, int
error)
blk_account_io_completion(rq, bytes);
blk_account_io_done(rq);
+ blk_mq_free_request(rq);
}
void blk_mq_complete_request(struct request *rq, int error)
{
trace_block_rq_complete(rq->q, rq);
- blk_mq_finish_request(rq, error);
+ /*
+ * If ->end_io is set, it's responsible for doing the rest of the
+ * completion.
+ */
if (rq->end_io)
rq->end_io(rq, error);
else
- blk_mq_free_request(rq);
+ blk_mq_finish_request(rq, error);
+
}
void __blk_mq_end_io(struct request *rq, int error)
@@ -984,7 +989,8 @@ int blk_mq_execute_rq(struct request_queue *q, struct
request *rq)
if (rq->errors)
err = -EIO;
- blk_mq_free_request(rq);
+ blk_mq_finish_request(rq, rq->errors);
+
return err;
}
EXPORT_SYMBOL(blk_mq_execute_rq);
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 52bf1f9..42d0110 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -27,6 +27,7 @@ void blk_mq_complete_request(struct request *rq, int error);
void blk_mq_run_request(struct request *rq, bool run_queue, bool async);
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_init_flush(struct request_queue *q);
+void blk_mq_finish_request(struct request *rq, int error);
/*
* CPU hotplug helpers
--
1.7.10.4
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