[PATCHv4] nvmet: implement unique discovery NQN

[Hannes Reinecke]

On 3/22/24 10:43, Chaitanya Kulkarni wrote:
> On 3/22/2024 12:09 AM, Hannes Reinecke wrote:
>> From: Hannes Reinecke <hare at suse.de>
>>
>> Unique discovery NQNs allow to differentiate between discovery
>> services from (typically physically separate) NVMe-oF subsystems.
>> This is required for establishing secured connections as otherwise
>> the credentials won't be unique and the integrity of the connection
>> cannot be guaranteed.
>> This patch adda a configfs attribute 'discovery_nqn' in the 'nvmet'
>> configfs directory to specify the unique discovery NQN.
>>
>> Signed-off-by: Hannes Reinecke <hare at suse.de>
>> ---
> 
> umm change log ?
> 
Just a rebase to latest head and modified the commit message slightly.
Not sure if that warranted a change log.

>>    drivers/nvme/target/configfs.c | 46 ++++++++++++++++++++++++++++++++++
>>    drivers/nvme/target/core.c     |  7 ++++++
>>    2 files changed, 53 insertions(+)
>>
>> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
>> index 77a6e817b315..e8ead4ab35aa 100644
>> --- a/drivers/nvme/target/configfs.c
>> +++ b/drivers/nvme/target/configfs.c
>> @@ -1613,6 +1613,11 @@ static struct config_group *nvmet_subsys_make(struct config_group *group,
>>    		return ERR_PTR(-EINVAL);
>>    	}
>>    
>> +	if (sysfs_streq(name, nvmet_disc_subsys->subsysnqn)) {
>> +		pr_err("can't create subsystem using unique discovery NQN\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>>    	subsys = nvmet_subsys_alloc(name, NVME_NQN_NVME);
>>    	if (IS_ERR(subsys))
>>    		return ERR_CAST(subsys);
>> @@ -2159,7 +2164,48 @@ static const struct config_item_type nvmet_hosts_type = {
>>    
>>    static struct config_group nvmet_hosts_group;
>>    
>> +static ssize_t nvmet_root_discovery_nqn_show(struct config_item *item,
>> +					     char *page)
>> +{
>> +	return sprintf(page, "%s\n", nvmet_disc_subsys->subsysnqn);
>> +}
>> +
> 
> snprintf() with PAGE_SIZE ?
> 
Ok.

>> +static ssize_t nvmet_root_discovery_nqn_store(struct config_item *item,
>> +		const char *page, size_t count)
>> +{
>> +	struct list_head *entry;
>> +	size_t len;
>> +
>> +	len = strcspn(page, "\n");
>> +	if (!len || len > NVMF_NQN_FIELD_LEN - 1)
>> +		return -EINVAL;
>> +
>> +	down_write(&nvmet_config_sem);
>> +	list_for_each(entry, &nvmet_subsystems_group.cg_children) {
>> +		struct config_item *item =
>> +			container_of(entry, struct config_item, ci_entry);
> 
> newline here ?
> 
Blasted configfs always eats into the line length limitation.
I see what I can do.

Thanks for the review.

Cheers,

Hannes