blk-flush: count inflight flush_data requests
The flush state machine use a double list to link all inflight
flush_data requests, to avoid issuing separate post-flushes for
these flush_data requests which shared PREFLUSH.
So we can't reuse rq->queuelist, this is why we need rq->flush.list
In preparation of the next patch that reuse rq->queuelist for flush
state machine, we change the double linked list to unsigned long
counter, which count all inflight flush_data requests.
This is ok since we only need to know if there is any inflight
flush_data request, so unsigned long counter is good.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230717040058.3993930-4-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk.h b/block/blk.h
index 608c5dc..686712e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -15,15 +15,14 @@ struct elevator_type;
extern struct dentry *blk_debugfs_root;
struct blk_flush_queue {
+ spinlock_t mq_flush_lock;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
blk_status_t rq_status;
unsigned long flush_pending_since;
struct list_head flush_queue[2];
- struct list_head flush_data_in_flight;
+ unsigned long flush_data_in_flight;
struct request *flush_rq;
-
- spinlock_t mq_flush_lock;
};
bool is_flush_rq(struct request *req);
