Hi, I've been working on a patchset to get rid of the ->bmap infrastructure. FIBMAP ioctl should be supported forever, so, basically I'm using Dave's idea to use ->fiemap() implementation to handle FIBMAP ioctl, however, I've been facing an issue with Ext4 FIEMAP in this case; basically: When issuing a FIEMAP ioctl to Ext4with something like this: fiemap->fm_start = block_num * blocksize; fiemap->fm_length = 1; fmap->fm_extent_count = 1; I was expecting the fiemap_extent returned, to contain the physical block from the logical request above, so: physical block == fiemap_ext.fe_physical / blocksize This works on XFS, which is using iomap_fiemap infrastructure. However, it doesn't work on Ext4. Ext4 always returns in fiemap_ext.fe_physical, the start of the extent, and not the offset requested initially (if it lies somewhere beyond the first block in the extent). Ted, is there any restriction why ext4_fiemap isn't using iomap_fiemap()? Or any reason why ext4 fiemap always returns the offset from the beginning of the extent? Would you oppose to have it updated to return the offset initially requested? Or maybe, change ext4_fiemap() to use iomap_fiemap()? I read the fiemap documentation, but I didn't get a clear understanding if fiemap should be returning the beginning of the extent, the offset initially requested, or if it depends on FS implementation. Cheers. -- Carlos
