[Samsung Galaxy S 5 Unified Development] lexridge:
I have never had a stock 6.0.1 on this phone. The last official version I had was TW 5.1.1. Could that perhaps make a difference in the partitioning tables (and EFS)? Could this be a possible explanation of why EFS tools cannot find any of my partitions when 14.1 is installed? Or perhaps none of the EFS tools have been updated to support the new AOSP 7 API.

This is my current mount table under CM-13-klteusc (#df):

Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 866608 92 866516 1% /dev
none 866608 0 866608 0% /sys/fs/cgroup
tmpfs 866608 0 866608 0% /mnt
/dev/block/mmcblk0p23 2345408 933516 1411892 40% /system
/dev/block/mmcblk0p26 12096020 11368056 727964 94% /data
/dev/block/mmcblk0p24 503944 23004 480940 5% /cache
/dev/block/mmcblk0p1 78800 7360 71440 10% /firmware
/dev/block/mmcblk0p2 65488 53728 11760 83% /firmware-modem
/dev/fuse 12096020 11368056 727964 94% /storage/emulated
/dev/fuse 62529568 46332064 16197504 75% /storage/11E5-2FE6

and this is the results of #cat /proc/mounts:

$ cat /proc/mounts
rootfs / rootfs ro,seclabel,relatime 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,size=866608k,nr_inodes=128920,mode=755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
/sys/kernel/debug /sys/kernel/debug debugfs rw,seclabel,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
none /sys/fs/cgroup tmpfs rw,seclabel,relatime,size=866608k,nr_inodes=128920,mode=750,gid=1000 0 0
none /sys/fs/cgroup/memory cgroup rw,relatime,memory 0 0
tmpfs /mnt tmpfs rw,seclabel,relatime,size=866608k,nr_inodes=128920,mode=755,gid=1000 0 0
none /dev/memcg cgroup rw,relatime,memory 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
none /sys/fs/cgroup/bfqio cgroup rw,relatime,bfqio 0 0
/dev/block/platform/msm_sdcc.1/by-name/system /system ext4 ro,seclabel,relatime,errors=panic,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 rw,seclabel,nosuid,nodev,noatime,noauto_da_alloc,errors=continue,commit=20,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/cache /cache ext4 rw,seclabel,nosuid,nodev,noatime,noauto_da_alloc,errors=continue,commit=20,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/apnhlos /firmware vfat ro,context=u:object_r:firmware_file:s0,relatime,uid=1000,gid=1026,fmask=0337,dmask=0227,codepage=cp437,iocharset=iso8859-1,shortname=lower,errors=remount-ro 0 0
/dev/block/platform/msm_sdcc.1/by-name/modem /firmware-modem vfat ro,context=u:object_r:firmware_file:s0,relatime,uid=1000,gid=1026,fmask=0337,dmask=0227,codepage=cp437,iocharset=iso8859-1,shortname=lower,errors=remount-ro 0 0
/dev/block/platform/msm_sdcc.1/by-name/efs /efs ext4 rw,seclabel,nosuid,nodev,noatime,journal_checksum,journal_async_commit,noauto_da_alloc,data=ordered 0 0
tmpfs /storage tmpfs rw,seclabel,relatime,size=866608k,nr_inodes=128920,mode=755,gid=1000 0 0
/dev/fuse /mnt/runtime/default/emulated fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /storage/emulated fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /mnt/runtime/read/emulated fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /mnt/runtime/write/emulated fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/block/vold/public:179_65 /mnt/media_rw/11E5-2FE6 vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1023,gid=1023,fmask=0007,dmask=0007,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
/dev/fuse /mnt/runtime/default/11E5-2FE6 fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /storage/11E5-2FE6 fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /mnt/runtime/read/11E5-2FE6 fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
/dev/fuse /mnt/runtime/write/11E5-2FE6 fuse rw,nosuid,nodev,noexec,noatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0

and last but not least, the command # ls -al /dev/block/platform/msm_sdcc.1/by-name:

drwxr-xr-x 2 root root 560 2014-07-23 00:02 .
drwxr-xr-x 4 root root 640 2014-07-23 00:02 ..
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 aboot -> /dev/block/mmcblk0p6
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 apnhlos -> /dev/block/mmcblk0p1
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 backup -> /dev/block/mmcblk0p18
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 boot -> /dev/block/mmcblk0p15
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 cache -> /dev/block/mmcblk0p24
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 carrier -> /dev/block/mmcblk0p25
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 dbi -> /dev/block/mmcblk0p4
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 ddr -> /dev/block/mmcblk0p5
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 efs -> /dev/block/mmcblk0p12
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 fota -> /dev/block/mmcblk0p17
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 fsc -> /dev/block/mmcblk0p19
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 fsg -> /dev/block/mmcblk0p9
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 modem -> /dev/block/mmcblk0p2
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 modemst1 -> /dev/block/mmcblk0p13
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 modemst2 -> /dev/block/mmcblk0p14
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 pad -> /dev/block/mmcblk0p10
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 param -> /dev/block/mmcblk0p11
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 persdata -> /dev/block/mmcblk0p22
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 persist -> /dev/block/mmcblk0p21
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 recovery -> /dev/block/mmcblk0p16
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 rpm -> /dev/block/mmcblk0p7
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 sbl1 -> /dev/block/mmcblk0p3
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 ssd -> /dev/block/mmcblk0p20
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 system -> /dev/block/mmcblk0p23
lrwxrwxrwx 1 root root 20 2014-07-23 00:02 tz -> /dev/block/mmcblk0p8
lrwxrwxrwx 1 root root 21 2014-07-23 00:02 userdata -> /dev/block/mmcblk0p26

I will do a comparison when I get back to putting cm14.1 back on, perhaps later this evening.