[PATCH 0/3] fiemap extension to add physical extent length

[Sweet Tea Dorminy <sweettea-kernel@dorminy.me>]

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 physical extent length 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 new field
will be unaffected by its presence.

This is based on next-20240307. 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, but I'm still waiting on more
tests. Please let me know what you think of the general idea!

Sweet Tea Dorminy (3):
  fs: add physical_length field to fiemap extents
  fs: update fiemap_fill_next_extent() signature
  btrfs: fiemap: return extent physical size

 Documentation/filesystems/fiemap.rst | 29 +++++++++----
 fs/bcachefs/fs.c                     |  6 ++-
 fs/btrfs/extent_io.c                 | 63 +++++++++++++++++-----------
 fs/ext4/extents.c                    |  1 +
 fs/f2fs/data.c                       |  8 ++--
 fs/f2fs/inline.c                     |  3 +-
 fs/ioctl.c                           |  8 ++--
 fs/iomap/fiemap.c                    |  2 +-
 fs/nilfs2/inode.c                    |  8 ++--
 fs/ntfs3/frecord.c                   |  6 ++-
 fs/ocfs2/extent_map.c                |  4 +-
 fs/smb/client/smb2ops.c              |  1 +
 include/linux/fiemap.h               |  2 +-
 include/uapi/linux/fiemap.h          | 24 +++++++----
 14 files changed, 108 insertions(+), 57 deletions(-)


base-commit: 1843e16d2df9d98427ef8045589571749d627cf7
-- 
2.44.0