Currently pdu of the flush rq is simlpy copied from another rq,
turns out it isn't a good approach:
- it isn't enough to initialize pointer field well, and
easy to cause bugs if some pointers filed are included
in pdu
- the copy isn't necessary, because the pdu should just
serve for submitting flush req purpose, like non-flush
case, and flush case of legacy block driver
- actually init_flush_rq/exit_flush_rq is needed for
seting up flush request.
So introduce these two callbacks for driver to handle the case
easily.
Signed-off-by: Ming Lei <ming....@canonical.com>
---
block/blk-flush.c | 11 +++++++++++
block/blk-mq.c | 2 ++
block/blk-mq.h | 1 +
include/linux/blk-mq.h | 9 +++++++++
4 files changed, 23 insertions(+)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 75ca6cd0..14654e1 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -485,5 +485,16 @@ int blk_mq_init_flush(struct request_queue *q)
GFP_KERNEL);
if (!q->flush_rq)
return -ENOMEM;
+
+ if (q->mq_ops->init_flush_rq)
+ return q->mq_ops->init_flush_rq(q, q->flush_rq);
+
return 0;
}
+
+void blk_mq_exit_flush(struct request_queue *q)
+{
+ /* flush_rq is freed centrally for both mq and legacy queue */
+ if (q->mq_ops->exit_flush_rq)
+ q->mq_ops->exit_flush_rq(q, q->flush_rq);
+}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 23386c0..1daef32 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1868,6 +1868,8 @@ void blk_mq_free_queue(struct request_queue *q)
{
struct blk_mq_tag_set *set = q->tag_set;
+ blk_mq_exit_flush(q);
+
blk_mq_del_queue_tag_set(q);
blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
diff --git a/block/blk-mq.h b/block/blk-mq.h
index b0bd9bc..ea9974f 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -28,6 +28,7 @@ struct blk_mq_ctx {
void __blk_mq_complete_request(struct request *rq);
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
int blk_mq_init_flush(struct request_queue *q);
+void blk_mq_exit_flush(struct request_queue *q);
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_free_queue(struct request_queue *q);
void blk_mq_clone_flush_request(struct request *flush_rq,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a1e31f2..d24c13e 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -85,6 +85,8 @@ typedef int (init_request_fn)(void *, struct request *,
unsigned int,
unsigned int, unsigned int);
typedef void (exit_request_fn)(void *, struct request *, unsigned int,
unsigned int);
+typedef int (init_flush_rq_fn)(struct request_queue *, struct request *);
+typedef void (exit_flush_rq_fn)(struct request_queue *, struct request *);
struct blk_mq_ops {
/*
@@ -119,6 +121,13 @@ struct blk_mq_ops {
*/
init_request_fn *init_request;
exit_request_fn *exit_request;
+
+ /*
+ * Called after flush request allocated by the block layer to
+ * allow the driver to set up driver specific data.
+ */
+ init_flush_rq_fn *init_flush_rq;
+ exit_flush_rq_fn *exit_flush_rq;
};
enum {
--
1.7.9.5
--
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