On Wed, 21 Sept 2022 at 11:17, Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> Hm, seems like this could avoid the goto into an if-block:
>
> static int fuse_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
> struct file *file, umode_t mode)
> {
> struct fuse_conn *fc = get_fuse_conn(dir);
> int err;
>
> if (fc->no_tmpfile)
> return -EOPNOTSUPP;
>
> err = fuse_create_open(dir, file->f_path.dentry, file, file->f_flags, mode, FUSE_TMPFILE);
> if (err == -ENOSYS) {
> fc->no_tmpfile = 1;
> err = -EOPNOTSUPP;
> }
> return err;
> }
Okay.
> > +
> > static int fuse_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
> > struct dentry *entry, umode_t mode)
> > {
> > @@ -1913,6 +1931,7 @@ static const struct inode_operations fuse_dir_inode_operations = {
> > .setattr = fuse_setattr,
> > .create = fuse_create,
> > .atomic_open = fuse_atomic_open,
> > + .tmpfile = fuse_tmpfile,
> > .mknod = fuse_mknod,
> > .permission = fuse_permission,
> > .getattr = fuse_getattr,
> > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> > index 488b460e046f..98a9cf531873 100644
> > --- a/fs/fuse/fuse_i.h
> > +++ b/fs/fuse/fuse_i.h
> > @@ -784,6 +784,9 @@ struct fuse_conn {
> > /* Does the filesystem support per inode DAX? */
> > unsigned int inode_dax:1;
> >
> > + /* Is tmpfile not implemented by fs? */
> > + unsigned int no_tmpfile:1;
>
> Just a nit, it might be nicer to turn this into a positive, i.e.,
> unsigned int has_tmpfile:1. Easier to understand as people usually
> aren't great at processing negations.
Fuse has zillions of these no_foobar flags. Turning this single one
into a positive would be much more confusing IMO.
Thanks,
Miklos
