CentOS – Extend Virtual Volumes on VM, New Space Not Occupied by /dev/mapper

I have a CentOS VM (on a windows host, managed with virtualbox) that ran out of disk space.

I extended the virtual disk size, then used gparted to assign the new space to the existing partition

Then I used lvextend to assign halves of the free space to /dev/cl/home and /dev/cl/root

However df show that the /dev/mapper/cl-home and /dev/mapper/cl-root haven't grown into the now available space even after a reboot.

What am I missing ? Any tutos I found about extending existing logical volumes considered the job done with lvextend…

df gives :

/dev/mapper/cl-root    39G     37G  1,2G  98% /
/dev/mapper/cl-home    19G     13G  5,7G  70% /home
/dev/sda1             976M    672M  238M  74% /boot

and lsblk :

NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    0  150G  0 disk 
├─sda1        8:1    0    1G  0 part /boot
└─sda2        8:2    0  149G  0 part 
  ├─cl-root 253:0    0   81G  0 lvm  /
  ├─cl-swap 253:1    0  6,4G  0 lvm  [SWAP]
  └─cl-home 253:2    0 61,6G  0 lvm  /home

and lvdisplay

  --- Logical volume ---
  LV Path                /dev/cl/swap
  LV Name                swap
  VG Name                cl
  LV UUID                <redacted>
  LV Write Access        read/write
  LV Creation host, time <redacted>
  LV Status              available
  # open                 2
  LV Size                6,40 GiB
  Current LE             1639
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/cl/home
  LV Name                home
  VG Name                cl
  LV UUID                <redacted>
  LV Write Access        read/write
  LV Creation host, time <redacted>
  LV Status              available
  # open                 1
  LV Size                <61,57 GiB
  Current LE             15761
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                <redacted>
  LV Write Access        read/write
  LV Creation host, time <redacted>
  LV Status              available
  # open                 1
  LV Size                <81,03 GiB
  Current LE             20743
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0