Messages in this thread | | | Date | Sat, 29 Aug 2020 23:12:04 +0100 | From | Matthew Wilcox <> | Subject | Re: [PATCH] fs: allow do_renameat2() over bind mounts of the same filesystem. |
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On Sat, Aug 29, 2020 at 11:23:34PM +0200, Florian Margaine wrote: > Al Viro <viro@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.
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