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

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
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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