Re: [PATCH 2/2] lightnvm: hold nvm_lock until finish the target creation

From: Wenwei Tao
Date: Thu May 19 2016 - 11:19:42 EST


Okay, I will rebase it on for-4.8/core.

2016-05-19 20:42 GMT+08:00 Matias BjÃrling <mb@xxxxxxxxxxx>:
> On 05/19/2016 08:38 AM, Wenwei Tao wrote:
>>
>> From: Wenwei Tao <ww.tao0320@xxxxxxxxx>
>>
>> When create a target, we check whether the target is
>> already exist first. If the answer is no, we release
>> the lock and continue the creation. This cannot prevent
>> concurrent creation of the same target, so hold the lock
>> until finish the target creation.
>>
>> Signed-off-by: Wenwei Tao <ww.tao0320@xxxxxxxxx>
>> ---
>> drivers/lightnvm/core.c | 18 +++++++++---------
>> 1 file changed, 9 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
>> index 160c1a6..a622081 100644
>> --- a/drivers/lightnvm/core.c
>> +++ b/drivers/lightnvm/core.c
>> @@ -791,6 +791,7 @@ static int nvm_create_target(struct nvm_dev *dev,
>> struct nvm_tgt_type *tt;
>> struct nvm_target *t;
>> void *targetdata;
>> + int ret = -ENOMEM;
>>
>> if (!dev->mt) {
>> pr_info("nvm: device has no media manager registered.\n");
>> @@ -801,21 +802,20 @@ static int nvm_create_target(struct nvm_dev *dev,
>> tt = nvm_find_target_type(create->tgttype);
>> if (!tt) {
>> pr_err("nvm: target type %s not found\n",
>> create->tgttype);
>> - up_write(&nvm_lock);
>> - return -EINVAL;
>> + ret = -EINVAL;
>> + goto err_unlock;
>> }
>>
>> t = nvm_find_target(create->tgtname);
>> if (t) {
>> pr_err("nvm: target name already exists.\n");
>> - up_write(&nvm_lock);
>> - return -EINVAL;
>> + ret = -EINVAL;
>> + goto err_unlock;
>> }
>> - up_write(&nvm_lock);
>>
>> t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
>> if (!t)
>> - return -ENOMEM;
>> + goto err_unlock;
>>
>> tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
>> if (!tqueue)
>> @@ -848,8 +848,6 @@ static int nvm_create_target(struct nvm_dev *dev,
>> t->type = tt;
>> t->disk = tdisk;
>> t->dev = dev;
>> -
>> - down_write(&nvm_lock);
>> list_add_tail(&t->list, &nvm_targets);
>> up_write(&nvm_lock);
>>
>> @@ -860,7 +858,9 @@ err_queue:
>> blk_cleanup_queue(tqueue);
>> err_t:
>> kfree(t);
>> - return -ENOMEM;
>> +err_unlock:
>> + up_write(&nvm_lock);
>> + return ret;
>> }
>>
>> static int __nvm_configure_create(struct nvm_ioctl_create *create)
>>
>
> Thanks. There is a couple of patches in the for-4.8/core that moves this
> logic to the gennvm media manager. Could you rebase this on top?