| Message ID | 20210521055116.1053587-5-hch@lst.de (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 958229a7c55f219b1cff99f939dabbc1b6ba7161 |
| Headers | show |
| Series | [01/26] block: refactor device number setup in __device_add_disk | expand |
On Fri, May 21, 2021 at 07:50:54AM +0200, Christoph Hellwig wrote: > 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 <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Luis
On 5/21/21 7:50 AM, Christoph Hellwig wrote: > 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 pitfalls > a lot of drivers did get wrong or still do. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > block/genhd.c | 7 +++++-- > include/linux/genhd.h | 1 + > 2 files changed, 6 insertions(+), 2 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/block/genhd.c b/block/genhd.c index eec266c9318d..e4974af3d729 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -541,7 +541,10 @@ 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); @@ -1116,7 +1119,7 @@ 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); } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 7e9660ea967d..a5443f0b139d 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -153,6 +153,7 @@ struct gendisk { unsigned long state; #define GD_NEED_PART_SCAN 0 #define GD_READ_ONLY 1 +#define GD_QUEUE_REF 2 struct kobject *slave_dir; struct timer_rand_state *random;
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 <hch@lst.de> --- block/genhd.c | 7 +++++-- include/linux/genhd.h | 1 + 2 files changed, 6 insertions(+), 2 deletions(-)