On Wed, 22 Apr 2020 14:44:46 -0600 Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: > e.g. from a 10m file created with truncate on two Btrfs file systems > > original holes format (default) > > item 6 key (257 EXTENT_DATA 0) itemoff 15768 itemsize 53 > generation 7412 type 1 (regular) > extent data disk byte 0 nr 0 > extent data offset 0 nr 10485760 ram 10485760 > extent compression 0 (none) > > On a file system with no-holes feature set, this item simply doesn't > exist. I think basically it works by inference. Both kinds of files > have size in the INODE_ITEM, e.g. > > item 4 key (257 INODE_ITEM 0) itemoff 32245 itemsize 160 > generation 889509 transid 889509 size 10485760 nbytes 0 > > Sparse extents are explicitly stated in the original format with disk > byte 0 in an EXTENT_DATA item; whereas in the newer format, sparse > extents exist whenever EXTENT_DATA items don't completely describe the > file's size. Ok this means that U-Boot currently gained support for the original sparse extents. I fear that current u-boot does not handle the new no-holes feature.
