parent inode from the current struct inode

parent inode from the current struct inode

[Jack David]

Hi All,

Is possible to get parent directory's inode structure from the current
inode? If so, how can I do that?
Also, is it possible to get the "struct file" if we have "struct inode" ??

Thanks,
J

parent inode from the current struct inode

[Philipp Ittershagen]

Hi Jack,

On Wed, Feb 8, 2012 at 8:48 AM, Jack David <jd6589@gmail.com> wrote:
> Hi All,
>
> Is possible to get parent directory's inode structure from the current
> inode? If so, how can I do that?

It should be possible to use the container_of macro to get the parent
dentry struct. Then, you can get the parent dentry d_parent and access
its inode. (Please correct me, if I'm wrong. I didn't test it).



Philipp

Re: 答复: parent inode from the current struct inode

[Jack David]

2012/2/8 Tom Lai(IT) <tomlai@utstar.com>:
> Hi Philipp,
>
> I checked 2.6.32 that dentry struct contained parent dentry struct.
>
>
> Hi Jack,
>
> On Wed, Feb 8, 2012 at 8:48 AM, Jack David <jd6589@gmail.com> wrote:
>> Hi All,
>>
>> Is possible to get parent directory's inode structure from the current
>> inode? If so, how can I do that?
>
> It should be possible to use the container_of macro to get the parent
> dentry struct. Then, you can get the parent dentry d_parent and access
> its inode. (Please correct me, if I'm wrong. I didn't test it).
>

Okay, I tried container_of, but it did not work. So I tried
d_obtain_alias() which worked.

But I am not sure if I  have to make a call to dput() as well in order
to free the dentry obtained.
Anyone can confirm this?

J

>
>
> Philipp
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies



-- 
J

Re: 答复: parent inode from the current struct inode

[Philipp Ittershagen]

Hi Jack,

On Wed, Feb 8, 2012 at 2:00 PM, Jack David <jd6589@gmail.com> wrote:
> Okay, I tried container_of, but it did not work. So I tried
> d_obtain_alias() which worked.
>
> But I am not sure if I ?have to make a call to dput() as well in order
> to free the dentry obtained.
> Anyone can confirm this?

since d_obtain_alias() calls dput when something goes wrong after
allocating the dentry, I'm assuming that you also have to call dput to
free the dentry.



Philipp