Subject: Re: [PATCH iproute2-next v2] lib/fs: fix issue when {name,open}_to_handle_at() is not implemented

From: Petr Vorel <[email-masked]>
Date: Fri, 30 Apr 2021 21:29:03 +0200

Hi,

> > +++ b/lib/fs.c
> > @@ -30,6 +30,27 @@
> >  /* if not already mounted cgroup2 is mounted here for iproute2's use */
> >  #define MNT_CGRP2_PATH  "/var/run/cgroup2"

> > +
> > +#ifndef defined HAVE_HANDLE_AT
> This is also wrong, it must be:
> #ifndef HAVE_HANDLE_AT

> > +struct file_handle {
> > +	unsigned handle_bytes;
> > +	int handle_type;
> > +	unsigned char f_handle[];
> > +};
> > +
> > +int name_to_handle_at(int dirfd, const char *pathname,
> > +	struct file_handle *handle, int *mount_id, int flags)
> > +{
> > +	return syscall(name_to_handle_at, 5, dirfd, pathname, handle,
> > +	               mount_id, flags);
> Also I overlooked bogus 5 parameter, why is here? Correct is:

> 	return syscall(__NR_name_to_handle_at, dfd, pathname, handle,
> 			   mount_id, flags);
Uh, one more typo on my side, sorry (dfd => dirfd):
	return syscall(__NR_name_to_handle_at, dirfd, pathname, handle,
 			   mount_id, flags);

Kind regards,
Petr

> > +}
> > +
> > +int open_by_handle_at(int mount_fd, struct file_handle *handle, int flags)
> > +{
> > +	return syscall(open_by_handle_at, 3, mount_fd, handle, flags);
> And here 3, correct version is is:
> 	return syscall(__NR_open_by_handle_at, mount_fd, handle, flags);

> + adding at the top:

> #ifndef HAVE_HANDLE_AT
> # include <sys/syscall.h>
> #endif

> Kind regards,
> Petr