On 2024-08-08 23:37, Greg Kroah-Hartman wrote: >> diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c >> index 8502ef68459b..72cc51dcf870 100644 >> --- a/fs/kernfs/file.c >> +++ b/fs/kernfs/file.c >> @@ -479,7 +479,7 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma) >> * It is not possible to successfully wrap close. >> * So error if someone is trying to use close. >> */ >> - if (vma->vm_ops && vma->vm_ops->close) >> + if (WARN_ON_ONCE(vma->vm_ops && vma->vm_ops->close)) > > So you just rebooted a machine that hits this, loosing data everywhere. > Not nice :( Well, apologies for that, but there's no way to know what every single machine out there is doing... However if this machine is using ->close when that's clearly marked as unsupported then shouldn't we fix that?