[PATCH 2/9] block: avoid repeated work in blk_mark_disk_dead

[Christoph Hellwig <hch@xxxxxx>]

Check if GD_DEAD is already set in blk_mark_disk_dead, and don't
duplicate the work already done.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 block/genhd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/genhd.c b/block/genhd.c
index 461999e9489937..9a35b8443f0b5f 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -586,7 +586,9 @@ void blk_mark_disk_dead(struct gendisk *disk)
 	/*
 	 * Fail any new I/O.
 	 */
-	set_bit(GD_DEAD, &disk->state);
+	if (test_and_set_bit(GD_DEAD, &disk->state))
+		return;
+
 	if (test_bit(GD_OWNS_QUEUE, &disk->state))
 		blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
 
-- 
2.39.2