02:48, Goffredo Baroncelli wrote:
> On Wednesday, 15 December, 2010, Li Zefan wrote:
>> Goffredo Baroncelli wrote:
>>> On Wednesday, 15 December, 2010, Li Zefan wrote:
>>>> h4) objectid asis, type asis, offset++ -> we should get the correct
> result.
>>> This fix the problem of the "missing subvolume". But for the other case
>>> (searching for more than one type) the problem still here.
>>>
>> I don't think so. And the above "h4" has showed how we search for more
>> than one type.
>>
>> The generic userland code for next search is:
>>
>> /* this is in essence the same as how we advance key in kernel code */
>> if (sk->min_offset < (u64)-1 && sk->min_offset < sk->max_offset)
>> sk->min_offset++;
>> else if (sk->min_type < (u8)-1 && sk->min_type < sk->max_type) {
>> sk->min_offset = 0;
>> sk->min_type++;
>> } else if (sk->min_objectid < (u64)-1 && sk->min_objectid < sk-
>> max_objectid){
>> sk->min_offset = 0;
>> sk->min_type = 0;
>
> Sorry but if you reset the sk->min_type to 0, this means that the min_type
> lost its purpose (act as lover bound of the acceptance criteria).
>
Yep, the changelog of Chris' commit has said that userland has to do this.
>> sk->min_objectid++;
>> } else
>> break;
>>
>> ioctl(...);
>>
>> for (i = 0; i < nr_items; i++) {
>> if (!filter(items[i]))
>> continue;
>
> So you are suggesting: "Move all tree items from kernel to user space and
> filter it in userspace ?". This mean a lot of un-needed kernel-space <->
> userspace transition...
>
Right, but it's fine so far. I'm not suggesting anything, but explaining
how the ioctl is working.
> Sorry I don't understand if we are talking about a workaround or a solution.
>
As Chris said, it's not perfect but we can just live along with it, until
we find some killer app that requests us to improve/expand this ioctl.
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