Re: [PATCH v7 02/16] block: improve capacity handling during zone revalidation

[Hannes Reinecke <hare@suse.de>]

On 9/8/26 10:57 AM, Damien Le Moal wrote:
> While executing blk_revalidate_disk_zones(), a disk capacity is looked at
> using get_capacity() several times: on entry to
> blk_revalidate_disk_zones(), when allocating zone revalidation arguments
> in disk_revalidate_zone_resources(), while validating zones in
> blk_revalidate_zone_cb() and one last time at the end of
> blk_revalidate_disk_zones() to check that all zones have been inspected.
> 
> Since this is all done while passthrough commands can be issued, it is
> possible that a capacity change operation (e.g. the removal of a storage
> element on a SCSI or SATA disk) is concurrently executed, potentially
> resulting in an inconsistent or conflicting revalidation with potentially
> out-of-bound accesses to the zone condition array.
> 
> Prevent issues by using get_capacity() once on entry to
> blk_revalidate_disk_zones(), remembering this capacity as a field of
> struct blk_revalidate_zone_args and using that field while revalidating
> zones. A final second call to get_capacity() is done at the end of
> blk_revalidate_disk_zones() to ensure that the disk capacity has not
> changed, thus revalidating the capacity (and number of zones) itself.
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> ---
>   block/blk-zoned.c | 19 +++++++++++++------
>   1 file changed, 13 insertions(+), 6 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
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