[PATCH 10/20] nvme: freeze the queue over ->lba_shift updates

[Damien Le Moal]

On 2020/09/28 21:35, Christoph Hellwig wrote:
> Ensure that there can't be any I/O in flight went we change the disk
> geometry in nvme_update_ns_info, most notable the LBA size by lifting
> the queue free from nvme_update_disk_info into the caller
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/nvme/host/core.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 443aba9c9fdd11..82cd03c0ba21ba 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2021,7 +2021,7 @@ static void nvme_update_disk_info(struct gendisk *disk,
>  		/* unsupported block size, set capacity to 0 later */
>  		bs = (1 << 9);
>  	}
> -	blk_mq_freeze_queue(disk->queue);
> +
>  	blk_integrity_unregister(disk);
>  
>  	atomic_bs = phys_bs = bs;
> @@ -2086,8 +2086,6 @@ static void nvme_update_disk_info(struct gendisk *disk,
>  		set_disk_ro(disk, true);
>  	else
>  		set_disk_ro(disk, false);
> -
> -	blk_mq_unfreeze_queue(disk->queue);
>  }
>  
>  static inline bool nvme_first_scan(struct gendisk *disk)
> @@ -2133,6 +2131,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
>  	struct nvme_ctrl *ctrl = ns->ctrl;
>  	int ret;
>  
> +	blk_mq_freeze_queue(ns->disk->queue);
>  	/*
>  	 * If identify namespace failed, use default 512 byte block size so
>  	 * block layer can use before failing read/write for 0 capacity.
> @@ -2150,30 +2149,39 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
>  			dev_warn(ctrl->device,
>  				"failed to add zoned namespace:%u ret:%d\n",
>  				ns->head->ns_id, ret);
> -			return ret;
> +			goto out_unfreeze;
>  		}
>  		break;
>  	default:
>  		dev_warn(ctrl->device, "unknown csi:%u ns:%u\n",
>  			ns->head->ids.csi, ns->head->ns_id);
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto out_unfreeze;
>  	}
>  
>  	ret = nvme_configure_metadata(ns, id);
>  	if (ret)
> -		return ret;
> +		goto out_unfreeze;
>  	nvme_set_chunk_sectors(ns, id);
>  	nvme_update_disk_info(ns->disk, ns, id);
> +	blk_mq_unfreeze_queue(ns->disk->queue);
> +
>  #ifdef CONFIG_NVME_MULTIPATH
>  	if (ns->head->disk) {
> +		blk_mq_freeze_queue(ns->head->disk->queue);
>  		nvme_update_disk_info(ns->head->disk, ns, id);
>  		blk_stack_limits(&ns->head->disk->queue->limits,
>  				 &ns->queue->limits, 0);
>  		blk_queue_update_readahead(ns->head->disk->queue);
>  		nvme_update_bdev_size(ns->head->disk);
> +		blk_mq_unfreeze_queue(ns->head->disk->queue);
>  	}
>  #endif
>  	return 0;
> +
> +out_unfreeze:
> +	blk_mq_unfreeze_queue(ns->disk->queue);
> +	return ret;
>  }
>  
>  static int nvme_validate_ns(struct nvme_ns *ns)
> 

Looks good.

Reviewed-by: Damien Le Moal <damien.lemoal at wdc.com>

-- 
Damien Le Moal
Western Digital Research