The original FIEMAP patch did not define the bits, btrfs would like to use a
flag for compressed extents. The PHYS_LENGTH flag emerged during patchset
revisions to keep backward compatibility and flexible fiemap API.
Currently, the 'filefrag' utility has no way to recognize and denote a
compressed extent. As implemented in btrfs right now, the compression step
splits a big extent into smaller chunks and this is reported as a heavily
fragmented file. Adding the flag to filefrag will at least give some
explanation why, this has been confusing users for some time already.
fiemap_fill_next_extent is extended and takes argument to fill the physical
Physical length is by default undefined. Btrfs use of compressed flag was
enhanced to reflect the fiemap changes. Patches reordered so the generic fiemap
The physical length is always set and equal to logical, or different and
then sets the COMPRESSED flag.
fiemap_extent::fe_length renamed to fe_logi_length
Based on feedback from Andreas, implement #1 from V2, current users of
fiemap_fill_next_extent (fs/, ext4, gfs2, ocfs2, nilfs2, xfs) updated
accordingly, no functional change.
Based on feedback from Andreas, the fiemap_extent is now able to hold the
physical extent length, to be filled by the filesystem callback.
1) extend fiemap_fill_next_extent to take phys_length and update all
users (ext4, gfs2, ocfs2, nilfs2, xfs)
David Sterba (6):
fiemap: fix comment at EXTENT_DATA_ENCRYPTED
fiemap: add fe_phys_length and EXTENT_PHYS_LENGTH flag
fiemap: add FIEMAP_EXTENT_DATA_COMPRESSED flag
Documentation/fiemap: Document DATA_COMPRESSED and PHYS_LENGTH flags
fiemap: rename fe_length to fe_logi_length
btrfs: set FIEMAP_EXTENT_DATA_COMPRESSED for compressed extents
Documentation/filesystems/fiemap.txt | 24 ++++++++++++++++++++----
fs/btrfs/extent_io.c | 11 ++++++++---
fs/ext4/extents.c | 4 ++--
fs/ext4/inline.c | 2 +-
fs/gfs2/inode.c | 2 +-
fs/ioctl.c | 21 ++++++++++++++-------
fs/nilfs2/inode.c | 8 +++++---
fs/ocfs2/extent_map.c | 4 ++--
fs/xfs/xfs_iops.c | 2 +-
include/linux/fs.h | 2 +-
include/uapi/linux/fiemap.h | 16 +++++++++++++---
11 files changed, 68 insertions(+), 28 deletions(-)