On Tue, Jan 6, 2009 at 11:06 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote:
> On Tue, Jan 6, 2009 at 10:58 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote:
>> On Tue, Jan 6, 2009 at 10:55 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote:
>>> We can find out no. of block currently being used by the donor inode,
>>> The data we read from donor inode has to be in some buffer or page,
>>
>> Since we know the blocknumber of donor inode, it should be possible to
>> do a raw read and get the memory address of the data page using
>> sb_bread() and then accessing bh->b_data . Isn't it ?
>
> Yes that's the way we can read blocks but the major issue here
> is copying this content to newly allocated block.
Apart from performance, is there anything else you are worried about ?
Thanks -
Manish
>>
>> Thanks -
>> Manish
>>
>>> is there a way we can associate this buffer with the reciever inode
>>> or write the contents of the buffer to the new inode.
>>>
>>>
>>> On Tue, Jan 6, 2009 at 10:46 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote:
>>>> On Tue, Jan 6, 2009 at 10:43 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote:
>>>>> On Tue, Jan 6, 2009 at 10:15 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote:
>>>>>> On Tue, Jan 6, 2009 at 7:42 PM, rishi agrawal <postrishi@xxxxxxxxx> wrote:
>>>>>>> yes i suppose the donor inode is known
>>>>>>> moreover the receiver inode's number is also known
>>>>>>>
>>>>>>> On Tue, Jan 6, 2009 at 6:54 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote:
>>>>>>>>
>>>>>>>> On Tue, Jan 6, 2009 at 4:06 PM, Rohit Sharma <imreckless@xxxxxxxxx> wrote:
>>>>>>>> > I want to read data blocks from one inode
>>>>>>>> > and copy it to other inode.
>>>>>>>> >
>>>>>>>> > I mean to copy data from data blocks associated with one inode
>>>>>>>> > to the data blocks associated with other inode.
>>>>>>>>
>>>>>>>> Copying 4K chunk of data itself is a costly operation. and depending
>>>>>>
>>>>>> Yes its a costly operation, but if this can be done then
>>>>>> we can definitely copy n blocks at a time.
>>>>>>
>>>>>>>> on the size of your donor inode this can be huge . Why do you want to
>>>>>>>> do that ? Do you know the inode of the donor inode ?
>>>>>>
>>>>>> For physically relocating a file from one disk to other.
>>>>>>
>>>>>> Yes Manish, i know the donor inode and i will create the reciever inode.
>>>>>
>>>>> I am guessing .......will something like this work ?
>>>>>
>>>>> ino_t donor_inode_num;
>>>>> struct inode *donor_inode = FS_iget(sb , donor_inode_num);
>>>>> struct FS_inode_info * fsi = FSI(donor_inode) ; // Do the regular
>>>>> container_of stuff here
>>>>>
>>>>> for ( i = 0; i < (donor_inode->i_size + sb->s_blocksize -
>>>>> 1)/sb->s_blocksize ; i ++ ) {
>>>>> // Do a memmove or memcpy here from fsi->i_data[i]
>>>>> }
>>>>>
>>>>> I am not sure though how will you prevent the donor inode from being
>>>>> changed/resized during this period.
>>>>
>>>> I am thinking of remounting ext2 in readonly mode, or i'll change the
>>>> mount flags to readonly. But i m not sure if internally i can copy the
>>>> data from one block to other.
>>>>
>>>>>
>>>>> Thanks -
>>>>> Manish
>>>>>
>>>>>
>>>>>>
>>>>>> Can we do that in kernel space.?
>>>>>>>>
>>>>>>>> thanks -
>>>>>>>> Manish
>>>>>>>> >
>>>>>>>> > Is that possible in kernel space.?
>>>>>>>> > --
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>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Regards,
>>>>>>> Rishi B. Agrawal
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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