On Thu, Aug 08, 2024 at 12:33:37PM -0600, Martin Oliveira wrote: > The next patch is going to remove .page_mkwrite from kernfs and will > WARN if an mmap implementation sets .page_mkwrite. > > In preparation for that change, and to make it consistent, add a WARN to > the ->close check. > > Co-developed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Signed-off-by: Martin Oliveira <martin.oliveira@xxxxxxxxxxxxx> > --- > fs/kernfs/file.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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 :(
