Re: [PATCH v3 2/6] scsi: Protect INQUIRY sysfs attributes with mutex

[Hannes Reinecke <hare@suse.de>]

On 4/30/26 00:49, Brian Bunker wrote:
> All INQUIRY-derived sysfs attributes (type, scsi_level, vendor, model,
> rev, cdl_supported, and the binary inquiry attribute) read data that
> can be updated during device rescan. These reads must be protected
> against concurrent updates.
> 
> Use the existing inquiry_mutex to protect access to these sysfs
> attributes. This ensures that userspace always sees consistent INQUIRY
> data, even if a rescan is updating the buffer concurrently.
> 
> Replace the sdev_rd_attr macro with two new helpers,
> sdev_rd_inquiry_attr_int and sdev_rd_inquiry_attr_str, which generate
> the show functions for INQUIRY-derived integer and string fields and
> take the inquiry_mutex around the field access.
> 
> This is preparatory work for adding INQUIRY data update support during
> device rescan operations.
> 
> Signed-off-by: Brian Bunker <brian@purestorage.com>
> Signed-off-by: Krishna Kant <krishna.kant@purestorage.com>
> ---
> v3:
>    - Use sysfs_emit() instead of snprintf() in the new show functions.
>    - Use guard(mutex)() for scoped lock acquisition and drop the local
>      ret variable.
> 
> v2:
>    - Protect all INQUIRY-derived fields (type, scsi_level, cdl_supported),
>      not just the string fields (vendor, model, rev) and binary inquiry
>      attribute. If we accept that INQUIRY data can change, we cannot assume
>      which fields will change.
>    - Replace the sdev_rd_attr macro with sdev_rd_inquiry_attr_int and
>      sdev_rd_inquiry_attr_str helpers to avoid duplicating the lock/unlock
>      boilerplate across each show function.
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

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