From 958229a7c55f219b1cff99f939dabbc1b6ba7161 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 21 May 2021 07:50:54 +0200 Subject: block: add a flag to make put_disk on partially initalized disks safer Add a flag to indicate that __device_add_disk did grab a queue reference so that disk_release only drops it if we actually had it. This sort out one of the major pitfals with partially initialized gendisk that a lot of drivers did get wrong or still do. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Luis Chamberlain Reviewed-by: Ulf Hansson Link: https://lore.kernel.org/r/20210521055116.1053587-5-hch@lst.de Signed-off-by: Jens Axboe --- block/genhd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'block/genhd.c') diff --git a/block/genhd.c b/block/genhd.c index 9fa734cb9cbd..c826db33a73e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -539,7 +539,10 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk, * Take an extra ref on queue which will be put on disk_release() * so that it sticks around as long as @disk is there. */ - WARN_ON_ONCE(!blk_get_queue(disk->queue)); + if (blk_get_queue(disk->queue)) + set_bit(GD_QUEUE_REF, &disk->state); + else + WARN_ON_ONCE(1); disk_add_events(disk); blk_integrity_add(disk); @@ -1107,7 +1110,7 @@ static void disk_release(struct device *dev) kfree(disk->random); xa_destroy(&disk->part_tbl); bdput(disk->part0); - if (disk->queue) + if (test_bit(GD_QUEUE_REF, &disk->state) && disk->queue) blk_put_queue(disk->queue); kfree(disk); } -- cgit v1.2.3