On 2021/05/06 22:18, Niklas Cassel wrote:
> From: Niklas Cassel <niklas.cassel@xxxxxxx>
>
> A common problem is that users upgrade their kernel to support NVMe ZNS
> devices, however, they still use the kernel uapi headers provided by their
> distro.
>
> This means that even if the kernel will populate the zone capacity fields
> for each zone in the zone report returned by the ioctl, fio will not know
> how to interpret that data.
>
> This leads to fio writing past the zone capacity, which will lead to
> I/O errors.
>
> It is not trivial for a user to realize that the kernel uapi headers
> provided by their distro is the reason for these I/O errors.
>
> In order to make it easier for these users, provide a copy of the current
> zoned block device kernel uapi structs.
>
> If the kernel uapi headers installed on the system are too old to support
> zone capacity, use the locally defined structs instead.
> If the installed headers are new enough to support zone capacity, use the
> installed headers.
>
> This way, fio will always be able to handle zone capacity (if the kernel
> supports it). At the same time, we will not redefine any structs from the
> installed headers if they are newer than our locally defined structs.
>
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxx>
> ---
> oslib/linux-blkzoned.c | 33 +++++++++++++++++++++++++++++++--
> 1 file changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/oslib/linux-blkzoned.c b/oslib/linux-blkzoned.c
> index f37c67fc..81e4e7f0 100644
> --- a/oslib/linux-blkzoned.c
> +++ b/oslib/linux-blkzoned.c
> @@ -23,6 +23,37 @@
>
> #include <linux/blkzoned.h>
>
> +/*
> + * If the uapi headers installed on the system lacks zone capacity support,
> + * use our local versions. If the installed headers are recent enough to
> + * support zone capacity, do not redefine any structs.
> + */
> +#ifndef CONFIG_HAVE_REP_CAPACITY
> +#define BLK_ZONE_REP_CAPACITY (1 << 0)
> +
> +struct blk_zone_v2 {
> + __u64 start; /* Zone start sector */
> + __u64 len; /* Zone length in number of sectors */
> + __u64 wp; /* Zone write pointer position */
> + __u8 type; /* Zone type */
> + __u8 cond; /* Zone condition */
> + __u8 non_seq; /* Non-sequential write resources active */
> + __u8 reset; /* Reset write pointer recommended */
> + __u8 resv[4];
> + __u64 capacity; /* Zone capacity in number of sectors */
> + __u8 reserved[24];
> +};
> +#define blk_zone blk_zone_v2
> +
> +struct blk_zone_report_v2 {
> + __u64 sector;
> + __u32 nr_zones;
> + __u32 flags;
> +struct blk_zone zones[0];
> +};
> +#define blk_zone_report blk_zone_report_v2
> +#endif /* CONFIG_HAVE_REP_CAPACITY */
> +
> /*
> * Read up to 255 characters from the first line of a file. Strip the trailing
> * newline.
> @@ -116,10 +147,8 @@ out:
> static uint64_t zone_capacity(struct blk_zone_report *hdr,
> struct blk_zone *blkz)
> {
> -#ifdef CONFIG_HAVE_REP_CAPACITY
> if (hdr->flags & BLK_ZONE_REP_CAPACITY)
> return blkz->capacity << 9;
> -#endif
> return blkz->len << 9;
> }
>
>
Looks good to me.
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
--
Damien Le Moal
Western Digital Research
