Revert "block: Fix a lockdep complaint triggered by request queue flushing"

This reverts commit b3c6a59975415bde29cfd76ff1ab008edbf614a9.

Now we can avoid nvme-loop lockdep warning of 'lockdep possible recursive locking'
by nvme-loop's lock class, no need to apply dynamically allocated lock class key,
so revert commit b3c6a5997541("block: Fix a lockdep complaint triggered by request
queue flushing").

This way fixes horrible SCSI probe delay issue on megaraid_sas, and it is reported
the whole probe may take more than half an hour.

Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reported-by: Qian Cai <cai@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-flush.c b/block/blk-flush.c
index bf51588762d8159ccb4ce068e72247ac2642eaa4..996d5d03dadec95c699e92e6d1f994d82f60648e 100644 (file)
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -69,7 +69,6 @@
 #include <linux/blkdev.h>
 #include <linux/gfp.h>
 #include <linux/blk-mq.h>
-#include <linux/lockdep.h>
 
 #include "blk.h"
 #include "blk-mq.h"
@@ -469,9 +468,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
        INIT_LIST_HEAD(&fq->flush_queue[1]);
        INIT_LIST_HEAD(&fq->flush_data_in_flight);
 
-       lockdep_register_key(&fq->key);
-       lockdep_set_class(&fq->mq_flush_lock, &fq->key);
-
        return fq;
 
  fail_rq:
@@ -486,7 +482,6 @@ void blk_free_flush_queue(struct blk_flush_queue *fq)
        if (!fq)
                return;
 
-       lockdep_unregister_key(&fq->key);
        kfree(fq->flush_rq);
        kfree(fq);
 }

diff --git a/block/blk.h b/block/blk.h
index 98f0b1ae264120f39ea78adaf2f6c6979a8664e1..d23d018fd2cd66055ff67860ffd4623541fb3cf1 100644 (file)
--- a/block/blk.h
+++ b/block/blk.h
@@ -25,7 +25,6 @@ struct blk_flush_queue {
        struct list_head        flush_data_in_flight;
        struct request          *flush_rq;
 
-       struct lock_class_key   key;
        spinlock_t              mq_flush_lock;
 };