Re: [PATCH] f2fs: fix up f2fs_get_parent issue to retrieve correctparent inode number

From: Leon Romanovsky
Date: Wed Dec 12 2012 - 12:13:04 EST


On Wed, Dec 12, 2012 at 8:50 AM, Fubo Chen <fubo.chen@xxxxxxxxx> wrote:
> On Wed, Dec 12, 2012 at 5:12 PM, Leon Romanovsky <leon@xxxxxxx> wrote:
>> On Wed, Dec 12, 2012 at 7:05 AM, Fubo Chen <fubo.chen@xxxxxxxxx> wrote:
>>>
>>> On Wed, Dec 12, 2012 at 3:37 PM, Namjae Jeon <linkinjeon@xxxxxxxxx> wrote:
>>> > + /* dot and dotdot dentries should have zero-value hash code */
>>> > + if (!memcmp(name, ".", 1) || !memcmp(name, "..", 2))
>>> > + return 0;
>>>
>>> That looks suspicious. If memcmp(name, "..", 2) == 0 then always
>>> memcmp(name, ".", 1) == 0. Why two tests ?
>>
>> It is not the case vice versa, so you still need to do two checks.
>> You need to distinguish dot(.), dotdot(..) and something with dot at
>> the beginning (for example - .o)
>
> Thanks for replying. I understand that the intention is what you
> explained. But to me the code says something else: "if the first byte
> of name is a dot, return 0". Did I see that correctly ?
Excellent catch, I agree with you It will also return 0 for every file
which starts from the dot.
The right solution must take name length into account.

>
> Fubo.



--
Leon Romanovsky | Independent Linux Consultant
www.leon.nu | leon@xxxxxxx
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