On Wed, May 23, 2018 at 02:19:40PM +0200, Christoph Hellwig wrote: > -static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) > - __releases(hctx->srcu) > -{ > - if (!(hctx->flags & BLK_MQ_F_BLOCKING)) > - rcu_read_unlock(); > - else > - srcu_read_unlock(hctx->srcu, srcu_idx); > -} > - > -static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) > - __acquires(hctx->srcu) > -{ > - if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { > - /* shut up gcc false positive */ > - *srcu_idx = 0; > - rcu_read_lock(); > - } else > - *srcu_idx = srcu_read_lock(hctx->srcu); > -}
I may have too ambitious on removing hctx_lock. That's actually nothing to do with the completion issues, but it is necessary for quiesce to work reliably. Otherwise, I still think there is some promise to the reset of the approach.