| Message ID | 20220720130541.1323531-2-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] blk-mq: fix error handling in __blk_mq_alloc_disk | expand |
On Wed, Jul 20, 2022 at 03:05:41PM +0200, Christoph Hellwig wrote: > To undo the all initialization from blk_mq_init_allocated_queue in case > of a probe failure where add_disk is never called we have to call > blk_mq_exit_queue from put_disk. > > This relies on the fact that drivers always call blk_mq_free_tag_set > after calling put_disk in the probe error path if they have a gendisk > at all. > > We should be doing this in general, but can't do it for the normal > teardown case (yet) as the tagset can be gone by the time the disk is > released once it was added. I hope to sort this out properly eventually > but for now this isolated hack will do it. > > Fixes: 6f8191fdf41d ("block: simplify disk shutdown") > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- Reviewed-by: Ming Lei <ming.lei@redhat.com>
diff --git a/block/genhd.c b/block/genhd.c index 44dfcf67ed96a..e1d5b10ac1931 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1138,6 +1138,18 @@ static void disk_release(struct device *dev) might_sleep(); WARN_ON_ONCE(disk_live(disk)); + /* + * To undo the all initialization from blk_mq_init_allocated_queue in + * case of a probe failure where add_disk is never called we have to + * call blk_mq_exit_queue here. We can't do this for the more common + * teardown case (yet) as the tagset can be gone by the time the disk + * is released once it was added. + */ + if (queue_is_mq(disk->queue) && + test_bit(GD_OWNS_QUEUE, &disk->state) && + !test_bit(GD_ADDED, &disk->state)) + blk_mq_exit_queue(disk->queue); + blkcg_exit_queue(disk->queue); disk_release_events(disk); @@ -1403,6 +1415,9 @@ EXPORT_SYMBOL(__blk_alloc_disk); * This decrements the refcount for the struct gendisk. When this reaches 0 * we'll have disk_release() called. * + * Note: for blk-mq disk put_disk must be called before freeing the tag_set + * when handling probe errors (that is before add_disk() is called). + * * Context: Any context, but the last reference must not be dropped from * atomic context. */
To undo the all initialization from blk_mq_init_allocated_queue in case of a probe failure where add_disk is never called we have to call blk_mq_exit_queue from put_disk. This relies on the fact that drivers always call blk_mq_free_tag_set after calling put_disk in the probe error path if they have a gendisk at all. We should be doing this in general, but can't do it for the normal teardown case (yet) as the tagset can be gone by the time the disk is released once it was added. I hope to sort this out properly eventually but for now this isolated hack will do it. Fixes: 6f8191fdf41d ("block: simplify disk shutdown") Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/genhd.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)