[PATCH v2] nvme: fix error handling in nvme_ns_report_zones

[Damien Le Moal]

On 2020/08/30 19:25, Christoph Hellwig wrote:
> nvme_submit_sync_cmd can return positive NVMe error codes in addition to
> the negative Linux error code, which are currently ignored.  Fix this
> by removing __nvme_ns_report_zones and handling the errors from
> nvme_submit_sync_cmd in the caller instead of multiplexing the return
> value and the zone size into a single return value.

s/zone size/number of zones reported/

> 
> Fixes: 240e6ee272c0 ("nvme: support for zoned namespaces")
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/nvme/host/zns.c | 38 +++++++++++++-------------------------
>  1 file changed, 13 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
> index 57cfd78731fbbe..b4f0543d74700e 100644
> --- a/drivers/nvme/host/zns.c
> +++ b/drivers/nvme/host/zns.c
> @@ -133,28 +133,6 @@ static void *nvme_zns_alloc_report_buffer(struct nvme_ns *ns,
>  	return NULL;
>  }
>  
> -static int __nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
> -				  struct nvme_zone_report *report,
> -				  size_t buflen)
> -{
> -	struct nvme_command c = { };
> -	int ret;
> -
> -	c.zmr.opcode = nvme_cmd_zone_mgmt_recv;
> -	c.zmr.nsid = cpu_to_le32(ns->head->ns_id);
> -	c.zmr.slba = cpu_to_le64(nvme_sect_to_lba(ns, sector));
> -	c.zmr.numd = cpu_to_le32(nvme_bytes_to_numd(buflen));
> -	c.zmr.zra = NVME_ZRA_ZONE_REPORT;
> -	c.zmr.zrasf = NVME_ZRASF_ZONE_REPORT_ALL;
> -	c.zmr.pr = NVME_REPORT_ZONE_PARTIAL;
> -
> -	ret = nvme_submit_sync_cmd(ns->queue, &c, report, buflen);
> -	if (ret)
> -		return ret;
> -
> -	return le64_to_cpu(report->nr_zones);
> -}
> -
>  static int nvme_zone_parse_entry(struct nvme_ns *ns,
>  				 struct nvme_zone_descriptor *entry,
>  				 unsigned int idx, report_zones_cb cb,
> @@ -182,6 +160,7 @@ static int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
>  			unsigned int nr_zones, report_zones_cb cb, void *data)
>  {
>  	struct nvme_zone_report *report;
> +	struct nvme_command c = { };
>  	int ret, zone_idx = 0;
>  	unsigned int nz, i;
>  	size_t buflen;
> @@ -190,14 +169,23 @@ static int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
>  	if (!report)
>  		return -ENOMEM;
>  
> +	c.zmr.opcode = nvme_cmd_zone_mgmt_recv;
> +	c.zmr.nsid = cpu_to_le32(ns->head->ns_id);
> +	c.zmr.numd = cpu_to_le32(nvme_bytes_to_numd(buflen));
> +	c.zmr.zra = NVME_ZRA_ZONE_REPORT;
> +	c.zmr.zrasf = NVME_ZRASF_ZONE_REPORT_ALL;
> +	c.zmr.pr = NVME_REPORT_ZONE_PARTIAL;
> +
>  	sector &= ~(ns->zsze - 1);
>  	while (zone_idx < nr_zones && sector < get_capacity(ns->disk)) {
>  		memset(report, 0, buflen);
> -		ret = __nvme_ns_report_zones(ns, sector, report, buflen);
> -		if (ret < 0)
> +
> +		c.zmr.slba = cpu_to_le64(nvme_sect_to_lba(ns, sector));
> +		ret = nvme_submit_sync_cmd(ns->queue, &c, report, buflen);
> +		if (ret)
>  			goto out_free;

Isn't there a problem here ? goto out_free will do "return ret;" and if ret is a
positive error code, then that value will be interpreted as a number of zones
reported. ret must be a standard "-Exxx" error code since this is a file method
and the caller does not expect an NVMe error code.

>  
> -		nz = min_t(unsigned int, ret, nr_zones);
> +		nz = min((unsigned int)le64_to_cpu(report->nr_zones), nr_zones);
>  		if (!nz)
>  			break;
>  
> 


-- 
Damien Le Moal
Western Digital Research