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 length. V5: Physical length is by default undefined. Btrfs use of compressed flag was enhanced to reflect the fiemap changes. Patches reordered so the generic fiemap go first. V4: 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 V3: 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. V2: 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(-) -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
