Re: [PATCH 3/3] nvme: change the interface between nvme and lightnvm

[Wenwei Tao]

You are right. Reset it to zero is not necessary.

2015-11-25 23:13 GMT+08:00 Matias BjÃrling <mb@xxxxxxxxxxx>:
> On 11/25/2015 01:42 PM, Wenwei Tao wrote:
>>
>> When nvme devices were removed, we need to handle the targets
>> build upon them properly: remove the existing targets, block
>> creations of new ones. To do this clean up job well, we
>> need to change the interface between nvme and lightnvm.
>>
>> Signed-off-by: Wenwei Tao <ww.tao0320@xxxxxxxxx>
>> ---
>>   drivers/nvme/host/lightnvm.c | 17 ++++++++++++++++-
>>   drivers/nvme/host/nvme.h     |  1 +
>>   drivers/nvme/host/pci.c      | 10 ++++++----
>>   3 files changed, 23 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
>> index e0b7b95..3f4ffb7 100644
>> --- a/drivers/nvme/host/lightnvm.c
>> +++ b/drivers/nvme/host/lightnvm.c
>> @@ -468,6 +468,14 @@ static void nvme_nvm_dev_dma_free(void *pool, void
>> *ppa_list,
>>         dma_pool_free(pool, ppa_list, dma_handler);
>>   }
>>
>> +static void nvme_nvm_dev_remove(struct request_queue *q)
>> +{
>> +       struct nvme_ns *ns = q->queuedata;
>> +
>> +       kref_put(&ns->kref, nvme_free_ns);
>> +
>> +}
>> +
>>   static struct nvm_dev_ops nvme_nvm_dev_ops = {
>>         .identity               = nvme_nvm_identity,
>>
>> @@ -482,13 +490,20 @@ static struct nvm_dev_ops nvme_nvm_dev_ops = {
>>         .destroy_dma_pool       = nvme_nvm_destroy_dma_pool,
>>         .dev_dma_alloc          = nvme_nvm_dev_dma_alloc,
>>         .dev_dma_free           = nvme_nvm_dev_dma_free,
>> +       .dev_remove             = nvme_nvm_dev_remove,
>>
>>         .max_phys_sect          = 64,
>>   };
>>
>>   int nvme_nvm_register(struct request_queue *q, char *disk_name)
>>   {
>> -       return nvm_register(q, disk_name, &nvme_nvm_dev_ops);
>> +       int ret;
>> +       struct nvme_ns *ns = q->queuedata;
>> +
>> +       ret = nvm_register(q, disk_name, &nvme_nvm_dev_ops);
>> +       if (!ret)
>> +               kref_get(&ns->kref);
>> +       return ret;
>>   }
>>
>>   void nvme_nvm_unregister(struct request_queue *q, char *disk_name)
>> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
>> index fdb4e5b..251ec9d 100644
>> --- a/drivers/nvme/host/nvme.h
>> +++ b/drivers/nvme/host/nvme.h
>> @@ -116,6 +116,7 @@ static inline u64 nvme_block_nr(struct nvme_ns *ns,
>> sector_t sector)
>>         return (sector >> (ns->lba_shift - 9));
>>   }
>>
>> +void nvme_free_ns(struct kref *kref);
>>   int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command
>> *cmd,
>>                 void *buf, unsigned bufflen);
>>   int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command
>> *cmd,
>> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
>> index 8187df2..f63223d 100644
>> --- a/drivers/nvme/host/pci.c
>> +++ b/drivers/nvme/host/pci.c
>> @@ -1960,13 +1960,10 @@ static int nvme_compat_ioctl(struct block_device
>> *bdev, fmode_t mode,
>>   #endif
>>
>>   static void nvme_free_dev(struct kref *kref);
>> -static void nvme_free_ns(struct kref *kref)
>> +void nvme_free_ns(struct kref *kref)
>>   {
>>         struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
>>
>> -       if (ns->type == NVME_NS_LIGHTNVM)
>> -               nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
>> -
>>         spin_lock(&dev_list_lock);
>>         ns->disk->private_data = NULL;
>>         spin_unlock(&dev_list_lock);
>> @@ -2533,6 +2530,11 @@ static void nvme_ns_remove(struct nvme_ns *ns)
>>   {
>>         bool kill = nvme_io_incapable(ns->dev) &&
>> !blk_queue_dying(ns->queue);
>>
>> +       if (ns->type == NVME_NS_LIGHTNVM) {
>> +               nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
>> +               ns->type = 0;
>
>
> Do we need to set it to zero, since we won't use it after its been removed?
>
>
>> +       }
>> +
>>         if (kill)
>>                 blk_set_queue_dying(ns->queue);
>>         if (ns->disk->flags & GENHD_FL_UP)
>>
>
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