blk-mq: rework flush sequencing logic
Witch to using a preallocated flush_rq for blk-mq similar to what's done
with the old request path. This allows us to set up the request properly
with a tag from the actually allowed range and ->rq_disk as needed by
some drivers. To make life easier we also switch to dynamic allocation
of ->flush_rq for the old path.
This effectively reverts most of
"blk-mq: fix for flush deadlock"
and
"blk-mq: Don't reserve a tag for flush request"
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0375654..b2d25ec 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -101,7 +101,7 @@
};
union {
struct call_single_data csd;
- struct work_struct mq_flush_data;
+ struct work_struct mq_flush_work;
};
struct request_queue *q;
@@ -451,13 +451,8 @@
unsigned long flush_pending_since;
struct list_head flush_queue[2];
struct list_head flush_data_in_flight;
- union {
- struct request flush_rq;
- struct {
- spinlock_t mq_flush_lock;
- struct work_struct mq_flush_work;
- };
- };
+ struct request *flush_rq;
+ spinlock_t mq_flush_lock;
struct mutex sysfs_lock;