Changing i_blocks field from ext4_inode.

[Ganesh Patil]

Hello,
        Can we change both the fields(struct ext4_extent_header and struct
ext4_extent) from i_blocks[..] of any file manually?
from i_block I got header & first extent of file as follows.

     struct ext4_extent_header  *eeh = (struct ext4_extent_header
*)EXT4_I(d_inode1)->i_data;
     struct ext4_extent *eex = EXT_FIRST_EXTENT(eeh);

from extent I got physical block numbers of file as follows.

     printk(KERN_INFO "high 16 bits of physical block=%d",eex->ee_start_hi);
     printk(KERN_INFO "low 32 bits of physical block=%d",
eex->ee_start_lo);

Now,I have to change this whole structure of i_blocks[..] so that new
structure of i_blocks[..] contains new header as well as new physical
blocks. I have tried in following way:

**for ext4_extent_header:
        eeh->eh_entries=myeeh->eh_entries;
        eeh->eh_magic=myeeh->eh_magic;
        eeh->eh_max=myeeh->eh_max;
        eeh->eh_depth=myeeh->eh_depth;
        eeh->eh_generation=myeeh->eh_generation
      where myeeh is the old ext4_extent_header from which I have to copy
fields in to new header i.e in eeh which contains the current header of
file.

**for  ext4_extent :
        eex->ee_block=myeex->ee_block;
        eex->ee_len=myeex->ee_len;
        eex->ee_start_hi=eex->ee_start_hi;
        eex->ee_start_lo=myeex->ee_start_lo;

     where myeex is the old ext4_extent from which I have to copy fields in
to new extent i.e in eex which contain the current extent of file.

I have done above code by writing my own module but it is not directly
making change in files ext4_inode i.e file content does not change even
though I have changed physical block numbers. If above method is wrong then
what is the correct way?
-- 
Regards,
Ganesh Patil.
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