Re: get_blocks_t semantics

[Badari Pulavarty <pbadari@us.ibm.com>]

Nir Tzachar wrote:

> hello list.
> 
> can someone please explain the exact semantics the get_block_t function 
> (which is passed to mpage_readpage(s)) should implement??
> i could not find any documentation, and existing code kind of baffled
> me...
> 
> my current understanding goes like this:
> if the block is present, call map_bh on the bh, with the physical block
> number.
> else, if "create" is set, allocate a new block for the inode, and again
> update the new physical block number.
> 
> is this all?? 
> 
> thanks.
> 

For a given file offset, get_block() function is supposed to return the
physical disk block# of the block. (and size of the block). If "create"
is one, it needs to allocate the block (if it doesn't already exist). 
Makes sense ?

Thanks,
Badari