Re: [PATCH] scsi: fix scsi device attributes registration

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 2021/11/11 19:35, Steffen Maier wrote:
> On 11/11/21 09:45, Damien Le Moal wrote:
>> Since the sdev_gendev device of a scsi device defines its attributes
>> using scsi_sdev_attr_groups as the groups field value of its device
>> type, the execution of device_add() in scsi_sysfs_add_sdev() register
>> with sysfs only the attributes defined using scsi_sdev_attr_groups. As
>> a results, the attributes defined by an LLD using the scsi host
>> sdev_groups attribute groups are never registered with sysfs and not
>> visible to the users.
>>
>> Fix this problem by removing scsi_sdev_attr_groups and manually setting
>> the groups field of a scsi device sdev_gendev to point to the scsi
>> device gendev_attr_groups. As the first entry of this array of
>> attribute groups is scsi_sdev_attr_group, using gendev_attr_groups as
>> the gendev groups result in all defined attributes to be created in
>> sysfs when device_add() is called.
>>
>> Fixes: 92c4b58b15c5 ("scsi: core: Register sysfs attributes earlier")
>> cc: Bart Van Assche <bvanassche@acm.org>
>> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
>> ---
>>   drivers/scsi/scsi_sysfs.c | 7 +------
>>   1 file changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
>> index d3d362289ecc..92c92853f516 100644
>> --- a/drivers/scsi/scsi_sysfs.c
>> +++ b/drivers/scsi/scsi_sysfs.c
>> @@ -1301,11 +1301,6 @@ static struct attribute_group scsi_sdev_attr_group = {
>>   	.is_bin_visible = scsi_sdev_bin_attr_is_visible,
>>   };
>>   
>> -static const struct attribute_group *scsi_sdev_attr_groups[] = {
>> -	&scsi_sdev_attr_group,
>> -	NULL
>> -};
>> -
>>   static int scsi_target_add(struct scsi_target *starget)
>>   {
>>   	int error;
>> @@ -1575,7 +1570,6 @@ int scsi_sysfs_add_host(struct Scsi_Host *shost)
>>   static struct device_type scsi_dev_type = {
>>   	.name =		"scsi_device",
>>   	.release =	scsi_device_dev_release,
>> -	.groups =	scsi_sdev_attr_groups,
>>   };
>>   
>>   void scsi_sysfs_device_initialize(struct scsi_device *sdev)
>> @@ -1601,6 +1595,7 @@ void scsi_sysfs_device_initialize(struct scsi_device *sdev)
>>   		}
>>   	}
>>   	WARN_ON_ONCE(j >= ARRAY_SIZE(sdev->gendev_attr_groups));
>> +	sdev->sdev_gendev.groups = sdev->gendev_attr_groups;
>>   
>>   	device_initialize(&sdev->sdev_dev);
>>   	sdev->sdev_dev.parent = get_device(&sdev->sdev_gendev);
>>
> 
> Damien, which kernel were you using?
> 
> Isn't this fixed by?:
> 
> next:
> 
> https://lore.kernel.org/linux-scsi/163478764102.7011.9375895285870786953.b4-ty@oracle.com/t/#mab0eeb4a8d8db95c3ace0013bfef775736e124cb
> ("scsi: core: Fix early registration of sysfs attributes for scsi_device")
> https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/commit/?h=5.16/scsi-staging&id=3a71f0f7a51259b3cb95d79cac1e19dcc5e89ce9
> https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/commit/?h=5.16/scsi-queue&id=3a71f0f7a51259b3cb95d79cac1e19dcc5e89ce9
> https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/commit/?h=for-next&id=3a71f0f7a51259b3cb95d79cac1e19dcc5e89ce9
> =>
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next-history.git/commit/?h=next-20211028&id=503f375baa99edff894eb1a534d2ac0b4f799573
> 
> soon in vanilla:
> 
> https://lore.kernel.org/linux-scsi/163612851260.17201.4106345384610850520.pr-tracker-bot@kernel.org/t/#md79869a3966ccceb30eef658b85743e49cf31dc1

I discovered the problem while testing libata tree which is currently based on
Linus master. So I completely missed this fix, which is even simpler than what I
sent :) I should have checked Martin's tree first !
Thanks for pointing this out. I tested and everything is fine.

Martin, Bart,

My apologies for the noise :)

-- 
Damien Le Moal
Western Digital Research