Re: [PATCH v2 13/13] block: flag zoned disks with GENHD_FL_NO_PART

On 8/6/26 6:04 PM, Damien Le Moal wrote:
> Zoned block devices do not support partitions. However, the partition
> table is nevertheless still inspected, and any partition found ignored
> with a warning in add_partition(). While this is generally not a problem,
> and in fact beneficial to the user as it indicates an invalid use of a
> zoned block device, scanning for a partition table on the device may
> result in issuing read operations to offline zones (e.g. after a disk head
> is depopulated for disks that support head management operations).
> 
> Since partitions are ignored anyway, completely disable partition scanning
> for zoned gendisks by setting the flag GENHD_FL_NO_PART in __add_disk().
> The existing check in add_partition() is left as-is to ensure that we
> still get a warning if for whatever reason, despite GENHD_FL_NO_PART, we
> still endup trying to add partitions.
> 
> Flagging zoned disks with GENHD_FL_NO_PART also has the benefit to expose
> through sysfs the ext_range attribute with the value of 1 instead of the
> default DISK_MAX_PARTS, thus correctly advertizing the fact that zoned
> disks do not support partitions.
> 
> Signed-off-by: Damien Le Moal <[email protected]>
> ---
>   block/genhd.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
Long overdue, if you ask me, and arguably not directly related to this 
patchset. But anyway.

Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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