2016-05-23 17:16 GMT+08:00 Matias Bjørling <mb@xxxxxxxxxxx>:
> On 05/23/2016 11:13 AM, Wenwei Tao wrote:
>>
>> From: Wenwei Tao <ww.tao0320@xxxxxxxxx>
>>
>> We may create targets with same name on different
>> backend devices, this is not what we want, so append
>> the device name to target name to make the new target
>> name unique in the system.
>>
>> Signed-off-by: Wenwei Tao <ww.tao0320@xxxxxxxxx>
>> ---
>> drivers/lightnvm/gennvm.c | 13 +++++++++++--
>> 1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
>> index 39ff0af..ecb09cb 100644
>> --- a/drivers/lightnvm/gennvm.c
>> +++ b/drivers/lightnvm/gennvm.c
>> @@ -43,9 +43,18 @@ static int gen_create_tgt(struct nvm_dev *dev, struct
>> nvm_ioctl_create *create)
>> struct gendisk *tdisk;
>> struct nvm_tgt_type *tt;
>> struct nvm_target *t;
>> + char tgtname[DISK_NAME_LEN];
>> void *targetdata;
>> int ret = -ENOMEM;
>>
>> + if (strlen(dev->name) + strlen(create->tgtname) + 1 >
>> DISK_NAME_LEN) {
>> + pr_err("nvm: target name too long. %s:%s\n",
>> + dev->name, create->tgtname);
>> + return -EINVAL;
>> + }
>> +
>> + sprintf(tgtname, "%s%s", dev->name, create->tgtname);
>> +
>> tt = nvm_find_target_type(create->tgttype, 1);
>> if (!tt) {
>> pr_err("nvm: target type %s not found\n",
>> create->tgttype);
>> @@ -53,7 +62,7 @@ static int gen_create_tgt(struct nvm_dev *dev, struct
>> nvm_ioctl_create *create)
>> }
>>
>> mutex_lock(&gn->lock);
>> - t = gen_find_target(gn, create->tgtname);
>> + t = gen_find_target(gn, tgtname);
>> if (t) {
>> pr_err("nvm: target name already exists.\n");
>> ret = -EINVAL;
>> @@ -73,7 +82,7 @@ static int gen_create_tgt(struct nvm_dev *dev, struct
>> nvm_ioctl_create *create)
>> if (!tdisk)
>> goto err_queue;
>>
>> - sprintf(tdisk->disk_name, "%s", create->tgtname);
>> + sprintf(tdisk->disk_name, "%s", tgtname);
>> tdisk->flags = GENHD_FL_EXT_DEVT;
>> tdisk->major = 0;
>> tdisk->first_minor = 0;
>>
>
> Hi Wenwei, what about the case where a target instance has multiple devices
> associated?
>
You mean a target may be build on multiple backend devices ?
> I am okay with having the user choosing a unique name for the target to be
> exposed.
You mean user should check the name before create the target?
Before move target mgmt into media mgr, that would be okay(after apply
lightnvm: hold lock until finish the target creation), since all
targets are in the global list.
Now consider below case:
There are two users A and B. A want to create target test0 upon
device0 B want to create test0 upon device1,
before creation they both check whether test0 is exist (e.g. by list
/dev/test0) , they all find test0 is not exist now, and they continue
their
creation. Both of them use disk name test0 to call add_disk, that
would cause panic.
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