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Subject: Re: [PATCH v1 7/8] null_blk: add error handling support for
 add_disk()
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     axboe@kernel.dk, bvanassche@acm.org, ming.lei@redhat.com,
        hch@infradead.org, jack@suse.cz, osandov@fb.com,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210512064629.13899-1-mcgrof@kernel.org>
 <20210512064629.13899-8-mcgrof@kernel.org>
 <842b6a8d-8880-a0da-a38b-39378dc6ebb9@suse.de>
 <20210512164709.GA4332@42.do-not-panic.com>
From:   Hannes Reinecke <hare@suse.de>
Message-ID: <d519b9ce-ad28-a266-786f-4128e0b91b9f@suse.de>
Date:   Wed, 12 May 2021 19:12:03 +0200
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On 5/12/21 6:47 PM, Luis Chamberlain wrote:
> On Wed, May 12, 2021 at 05:16:39PM +0200, Hannes Reinecke wrote:
>> On 5/12/21 8:46 AM, Luis Chamberlain wrote:
>>> We never checked for errors on add_disk() as this function
>>> returned void. Now that this is fixed, use the shiny new
>>> error handling.
>>>
>>> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
>>> ---
>>>    drivers/block/null_blk/main.c | 9 +++++++--
>>>    1 file changed, 7 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
>>> index 5f006d9e1472..2346d1292b26 100644
>>> --- a/drivers/block/null_blk/main.c
>>> +++ b/drivers/block/null_blk/main.c
>>> @@ -1699,6 +1699,7 @@ static int init_driver_queues(struct nullb *nullb)
>>>    static int null_gendisk_register(struct nullb *nullb)
>>>    {
>>> +	int ret;
>>>    	sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT;
>>>    	struct gendisk *disk;
>>> @@ -1719,13 +1720,17 @@ static int null_gendisk_register(struct nullb *nullb)
>>>    	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
>>>    	if (nullb->dev->zoned) {
>>> -		int ret = null_register_zoned_dev(nullb);
>>> +		ret = null_register_zoned_dev(nullb);
>>>    		if (ret)
>>>    			return ret;
>>>    	}
>>> -	add_disk(disk);
>>> +	ret = add_disk(disk);
>>> +	if (ret) {
>>
>> unregister_zoned_device() ?
> 
> That function does not exist, do you mean null_free_zoned_dev()? If so
> that is done by the caller.
> 
What I intended to say is that you are calling 
'null_register_zoned_dev()' at one point, but don't call a cleanup 
function if there is an error later in the path, leaving the caller to 
guess whether null_register_zoned_dev() has been called or not.
So we should call the cleanup function here, too.

Cheers,

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