On Sat, Aug 29, 2020 at 11:23:34PM +0200, Florian Margaine wrote: > Al Viro <v...@zeniv.linux.org.uk> writes: > > > On Fri, Aug 28, 2020 at 10:40:35PM +0200, Florian Margaine wrote: > >> There's currently this seemingly unnecessary limitation that rename() > >> cannot work over bind mounts of the same filesystem, > > > > ... is absolutely deliberate - that's how you set a boundary in the > > tree, preventing both links and renames across it. > > Sorry, I'm not not sure I understand what you're saying.
Al's saying this is the way an administrator can intentionally prevent renames. > /* > * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on > * the same mount. Practically, they only need to be on the same file > * system. > */ > if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) > return -EXDEV; clone doesn't change the contents of a file, merely how they're laid out on storage. There's no particular reason for an administrator to prohibit clone across mount points.