On Wed, Oct 22, 2014 at 08:28:53AM -0400, Bob Peterson wrote: > Yes, I thought about that. > One of my early prototypes had a separate function used by fiemap. > Function __generic_block_fiemap would call get_block() which > returned an indication of a hole as it does today. When it saw > the hole, fiemap called a new function get_hole_size() that was > passed in like get_block. The problem is: it's grossly inefficient, > since the new function get_hole_size() has to redo most of the work > that get_block just did (at least in the case of GFS2). (Which in the > case of a 1PB sparse file is non-trivial, since it involves several > levels of metadata indirection). Combining it with get_block made it > much more efficient. > > Making a separate get_block_map_fiemap() function just seems like an > exercise in redundancy. I was thinking of replacing get_blocks entirely. We're not actually using a buffer_head in fiemap, so the interface seems somewhat awkward. If it used something like the iomap interface proposed by Dave long time ago we'd have a much saner interface that for example XFS could use as well. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
