dentry object

dentry object

[Ashish Khurange]

Hi,
 From a given dentry, i want to generate that files absolute path. I 
don't want to use d_path, because it doesn't cross mount points.
Here is the algorithm what I have decided.

1. From dentry object get dname.
2. store in string
3. if IS_ROOT (dentry) goto stop
3. find its parent using dentry->parent
4. go to 1.

Stop.

Will this work?

I have one more question, when I have dentry of a file, then if dentries 
of all its parents up to '/' are present in the dcache?

Regards,
- Ashish K.

Re: dentry object

[phillip]

ashishk@it.iitb.ac.in wrote:
> Hi,
>  From a given dentry, i want to generate that files absolute path. I 
> don't want to use d_path, because it doesn't cross mount points.
> Here is the algorithm what I have decided.
> 
> 1. From dentry object get dname.
> 2. store in string
> 3. if IS_ROOT (dentry) goto stop
> 3. find its parent using dentry->parent
> 4. go to 1.
> 
> Stop.
> 
> Will this work?
> 
> I have one more question, when I have dentry of a file, then if dentries 
> of all its parents up to '/' are present in the dcache?
> 

AFAIK yes, unless the filesystem is being exported in which case this may
not hold.  Read Documentation/filesystems/Exporting.

Phillip

> Regards,
> - Ashish K.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
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> 

Re: dentry object

[Ashish Khurange]

phillip@lougher.demon.co.uk wrote:

I am sorry, if I am not using right terms. Please consider.

I have one basic query. I tried to google for 'dentry object' but didnt 
found the right answer. When I have dentry object of a file. Can I 
traverse till root's dentry using dentry->d_parent, step by step?

How does kernel shrinks dentry cache? Does it removes any of the dentry 
which is in 'parent path' of the concerned dentry object?

If kernel can remove such parent dentry, what happens when I access 
dentry->d_parent.

Thanks,
- Ashish

>
>
>  
>

>ashishk@it.iitb.ac.in wrote:
>  
>
>>Hi,
>> From a given dentry, i want to generate that files absolute path. I 
>>don't want to use d_path, because it doesn't cross mount points.
>>Here is the algorithm what I have decided.
>>
>>1. From dentry object get dname.
>>2. store in string
>>3. if IS_ROOT (dentry) goto stop
>>3. find its parent using dentry->parent
>>4. go to 1.
>>
>>Stop.
>>
>>Will this work?
>>
>>I have one more question, when I have dentry of a file, then if dentries 
>>of all its parents up to '/' are present in the dcache?
>>
>>    
>>
>
>AFAIK yes, unless the filesystem is being exported in which case this may
>not hold.  Read Documentation/filesystems/Exporting.
>
>Phillip
>
>  
>
>>Regards,
>>- Ashish K.
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
>>the body of a message to majordomo@vger.kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>    
>>
>
>  
>

Re: dentry object

[Ian Kent]

On Tue, 28 Feb 2006, Ashish Khurange wrote:

> Hi,
> From a given dentry, i want to generate that files absolute path. I don't want
> to use d_path, because it doesn't cross mount points.

Don't think this will cross mountpoints.

dentry->d_parent -> dentry at the root of a filesystem.

Check out fs/dcache.c:__d_path and look moe closely at d_path.

> Here is the algorithm what I have decided.
> 
> 1. From dentry object get dname.
> 2. store in string
> 3. if IS_ROOT (dentry) goto stop
> 3. find its parent using dentry->parent
> 4. go to 1.
> 
> Stop.
> 
> Will this work?
> 
> I have one more question, when I have dentry of a file, then if dentries of
> all its parents up to '/' are present in the dcache?
> 
> Regards,
> - Ashish K.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>