I've been trying to implement a file size validator in django on a filefield, but I can't really make it work.

Everything works right until I add this validator. After I add it, I can't upload files anymore at all. The error says "File field does not have a full_clean attribute".

views.py

from django.shortcuts import render, get_object_or_404
from .models import Oferta, CV
from django.contrib import messages
from django.core.paginator import Paginator

def incarcarecv(req):
    context = {
        'title': "Incarcare CV | Best DAVNIC73"
    }
    if req.method == 'POST':
        nume = req.POST['nume']
        prenume = req.POST['prenume']
        telefon = req.POST['telefon']
        email = req.POST['email']
        cv = req.FILES['CV']
        if(req.user.is_authenticated):
            cv_upload = CV(
            solicitant=req.user,
            nume=nume,
            prenume=prenume,
            telefon=telefon,
            emailContact=email
            )
            cv_upload.CVFile.full_clean()
            cv_upload.CVFile.save(cv.name, cv)  
            cv_upload.save()
            req.user.profile.cvuri.append(cv_upload.id)
            req.user.profile.save()
            messages.success(req, 'CV depus cu succes!')
        else:
            messages.error(req, 'Trebuie sa fii logat pentru a depune CV-ul!')
    return render(req, "../templates/pagini/incarcare-cv.html", context)

models.py

from django.db import models
from django.contrib.auth.models import User
from .validators import validate_file_size

# Create your models here.
class Oferta(models.Model):
    solicitant = models.ForeignKey(User, on_delete=models.CASCADE)
    dataSolicitare = models.DateField(auto_now_add=True)
    cor = models.CharField(max_length=25)
    denumireMeserie = models.CharField(max_length=12)
    locuri = models.IntegerField()
    agentEconomic = models.CharField(max_length=50)
    adresa = models.CharField(max_length=150)
    dataExpirare = models.DateField()
    experientaSolicitata = models.CharField(max_length=200)
    studiiSolicitate = models.CharField(max_length=200)
    judet = models.CharField(max_length=20)
    localitate = models.CharField(max_length=25)
    telefon = models.CharField(max_length=12)
    emailContact = models.EmailField(max_length=40)
    rezolvata = models.BooleanField(default=False)
    def __str__(self):
        return self.cor

class CV(models.Model):
    solicitant = models.ForeignKey(User, on_delete=models.CASCADE)
    dataUploadCV = models.DateField(auto_now_add=True)
    nume = models.CharField(max_length=12)
    prenume = models.CharField(max_length=12)
    telefon = models.CharField(max_length=12)
    emailContact = models.EmailField(max_length=40)
    CVFile = models.FileField(upload_to='documents/%d/%m/%Y', validators=[validate_file_size])
    rezolvata = models.BooleanField(default=False)
    def __str__(self):
        return self.nume + " " + self.prenume + ": " + str(self.CVFile)

validators.py

from django.core.exceptions import ValidationError


def validate_file_size(value):
    filesize=value.size

    if filesize > 5000000:
        raise ValidationError("Maximum 5MB!")    

I just can't seem to get why. Can you help me fix my code? As far as I know, .full_clean() runs some default django validators + the ones set in the model.

But actually it does not work.

Exception Value:    
'FieldFile' object has no attribute 'full_clean'

Can you explain to me why is this happening and how can I make my validator run?

Thanks.

//by the way, someone recommended to change the order of the lines like this -

cv_upload.CVFile.save(cv.name, cv) 
cv_upload.CVFile.full_clean()    

but it does not work anyway.