How to atomically defragment ext4 directories

Fragmentation seems to create a lot of unnecessary seeks when traversing a directory tree on a HDD: # stat -c %F 00 01 02 directory directory directory # filefrag -v 00 01 02 Filesystem type is: ef53 File size of 00 is 12288 (3 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 0: 428351942.. 428351942: 1: 1: 1.. 2: 428352760.. 428352761: 2: 428351943: last,eof 00: 2 extents found File size of 01 is 12288 (3 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 0: 428351771.. 428351771: 1: 1: 1.. 2: 428891667.. 428891668: 2: 428351772: last,eof 01: 2 extents found File size of 02 is 12288 (3 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 0: 428351795.. 428351795: 1: 1: 1.. 2: 428352705.. 428352706: 2: 428351796: last,eof 02: 2 extents found e4defrag isn't able to defrag them # e4defrag -v 00 ext4 defragmentation for directory(00) [1/116] "00" File is not regular file [ NG ] So how do I defragment a directory? Not its contents, but the directory itself. The directories are in use, so it should be done atomically, just like defragmenting regular files does not interfere with their use.