Re: [PATCHv4 6/8] nvme: export I/O failure count when no path is available via sysfs

[John Garry <john.g.garry@oracle.com>]

On 16/05/2026 19:36, Nilay Shroff wrote:
> +

I'm just looking at this now for the scsi multipath/libmultipath work.

> +static ssize_t io_fail_no_available_path_count_store(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	int err;
> +	unsigned long fail_cnt;
> +	struct gendisk *disk = dev_to_disk(dev);
> +	struct nvme_ns_head *head = disk->private_data;
> +
> +	err = kstrtoul(buf, 0, &fail_cnt);

is fail_cnt ever going to be non-zero? I assume that we allow the value 
to be stored to just reset the counter (to zero).

> +	if (err)
> +		return -EINVAL;
> +
> +	atomic_long_set(&head->io_fail_no_available_path_count, fail_cnt);
> +
> +	return count;
> +}
> +
> +DEVICE_ATTR_RW(io_fail_no_available_path_count);

Thanks,
John