For many years, various btrfs users have written programs to discover the actual disk space used by files, using root-only interfaces. However, this information is a great fit for fiemap: it is inherently tied to extent information, all filesystems can use it, and the capabilities required for FIEMAP make sense for this additional information also. Hence, this patchset adds various additional information to fiemap, and extends btrfs to return it. This uses some of the reserved padding in the fiemap extent structure, so programs unaware of the changes will be unaffected. This is based on next-20240325. I've tested the btrfs part of this with the standard btrfs testing matrix locally, and verified that the physical extent information returned there is correct. Changelog: v2: - Adopted PHYS_LEN flag and COMPRESSED flag from the previous version, as per Andreas Dilger' comment. https://patchwork.ozlabs.org/project/linux-ext4/patch/4f8d5dc5b51a43efaf16c39398c23a6276e40a30.1386778303.git.dsterba@xxxxxxx/ v1: https://lore.kernel.org/linux-fsdevel/20240315030334.GQ6184@frogsfrogsfrogs/T/#t Sweet Tea Dorminy (5): fs: fiemap: add physical_length field to extents fs: fiemap: update fiemap_fill_next_extent() signature fs: fiemap: add new COMPRESSED extent state btrfs: fiemap: emit new COMPRESSED fiemap state. btrfs: fiemap: return extent physical size Documentation/filesystems/fiemap.rst | 35 ++++++++++---- fs/bcachefs/fs.c | 7 +-- fs/btrfs/extent_io.c | 72 ++++++++++++++++++---------- fs/ext4/extents.c | 1 + fs/f2fs/data.c | 8 ++-- fs/f2fs/inline.c | 3 +- fs/ioctl.c | 11 +++-- fs/iomap/fiemap.c | 2 +- fs/nilfs2/inode.c | 6 +-- fs/ntfs3/frecord.c | 7 +-- fs/ocfs2/extent_map.c | 4 +- fs/smb/client/smb2ops.c | 1 + include/linux/fiemap.h | 2 +- include/uapi/linux/fiemap.h | 34 ++++++++++--- 14 files changed, 130 insertions(+), 63 deletions(-) base-commit: 1fdad13606e104ff103ca19d2d660830cb36d43e -- 2.43.0