what's relationship between VFS inode and ext3_inode?

[Theodore Tso]

On Tue, Jun 02, 2009 at 04:56:33PM +0800, Zhang Shukun wrote:
> hi,
> 
> in kernel space ,if i get the i_ino(inode mumber ) of a file, and next how
> could i get the block number of this file? in VFS layer the inode struct
> haven't i_block[] array to point to the blocks. but in ext3_inode struct, it
> has. what's the relationship between the VFS inode and ext3_inode?
> 
> 
> how do i get the block number of a file ?  the path is as follow:
> 
> filp_open("/bin/ls",O_RDONLY,0)---- -->struct file *------->struct dentry
> *f_dentry----->struct inode *d_inode-------->struct inode{}------------->
> ???------------>struct ext3_inode{}---------->__le32
> i_block[EXT2_N_BLOCKS];
> 
> from VFS inode to ext3_inode , i don't know how to transfer?? Thanks!

What are you trying to do?  For userspace programs, just use the
FIBMAP (or FIEMAP) ioctl's.

						- Ted