Wrong inode: corrupted f2fs, fsck.f2fs cannot repair

A f2fs partition on my Android phone has recently become corrupted. It will still mount fine; however, I completely lost access to one directory (/data/media/0 ), which now shows as empty. Yet the disk space hasn't changed at all. When running fsck.f2fs from the terminal, it refuses to check on a mounted filesystem. I cannot unmount the data partition or remount it as read-only. Fine. After rebooting under recovery mode, where the partition is not mounted, I get this when running fsck.f2fs: ~ # fsck.f2fs /dev/block/mmcblk0p39 Info: sector size = 512 Info: total sectors = 21425920 (in 512bytes) Assertion failed! [fsck_chk_dentry_blk: 563] le32_to_cpu(de_blk->dentry[i].hash_code) == hash_code So it still refuses to help me and it now fails with an obscure error… stating the directory gives me: root@victara:/ # stat /data/media/0 File: `/data/media/0' Size: 4096 Blocks: 24 IO Blocks: 4096 directory Device: 10307h/66311d Inode: 4 Links: 35 Access: (770/drwxrwx---) Uid: (1023/media_rw) Gid: (1023/media_rw) Access: 2016-04-04 16:55:56.800148001 Modify: 2016-04-05 02:47:44.314999998 Change: 2016-04-05 02:47:44.314999998 The inode (number?) seemed to be quite low… So I checked other directories: root@victara:/ # stat /data/media/ File: '/data/media/' Size: 4096 Blocks: 16 IO Block: 4096 directory Device: 10307h/66311d Inode: 4078 Links: 4 Access: (0770/drwxrwx---) Uid: ( 1023/media_rw) Gid: ( 1023/media_rw) __bionic_open_tzdata: couldn't find any tzdata when looking for localtime! __bionic_open_tzdata: couldn't find any tzdata when looking for GMT! __bionic_open_tzdata: couldn't find any tzdata when looking for posixrules! Access: 2016-04-04 14:48:25.000000000 Modify: 1970-01-01 02:27:21.000000000 Change: 1970-02-07 02:30:36.000000000 root@victara:/ # stat /data/media/obb File: `/data/media/obb' Size: 4096 Blocks: 16 IO Blocks: 4096 directory Device: 10307h/66311d Inode: 4080 Links: 3 Access: (775/drwxrwxr-x) Uid: (1023/media_rw) Gid: (1023/media_rw) Access: 1970-01-01 03:27:21.519999999 Modify: 2016-03-17 22:38:30.505748550 Change: 2016-04-04 17:42:31.569999988 It looks like the parent dir (/data/media) has inode 4078, another child of the parent (/data/media/obb) has inode 4080. So, logically, /data/media/0 should have inode 4079, but stat tells me it has inode 4. So it looks like the filesystem metadata got corrupted. Without help from fsck.f2fs and debugfs (which sadly doesn't exist for f2fs), and in a pretty minimal Linux environment (Android recovery), is there a way I can correct the inode number or something else I can do to recover access to my data? --- Interestingly, the directory still seems to be taking up disk space, and it is considered as "not empty" so I cannot remove it. root@victara:/data/media # rm -rf 0 rm: 0: Directory not empty 1|root@victara:/data/media # ls 0 obb root@victara:/data/media # ls -al 0 total 0 *IMPORTANT: I cannot test solutions anymore since I need the phone and the storage space and reformatted the partition.*