Messages in this thread | | | Date | Tue, 18 Feb 2020 20:42:33 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH v3 09/25] fs: add is_userns_visible() helper |
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On Tue, Feb 18, 2020 at 03:33:55PM +0100, Christian Brauner wrote: > Introduce a helper which makes it possible to detect fileystems whose > superblock is visible in multiple user namespace. This currently only > means proc and sys. Such filesystems usually have special semantics so their > behavior will not be changed with the introduction of fsid mappings.
Hi,
I'm afraid I've got a bit of a hangup about the terminology here. I *think* what you mean is that SB_I_USERNS_VISIBLE is an fs whose uids are always translated per the id mappings, not fsid mappings. But when I see the name it seems to imply that !SB_I_USERNS_VISIBLE filesystems can't be seen by other namespaces at all.
Am I right in my first interpretation? If so, can we talk about the naming?
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> > --- > /* v2 */ > unchanged > > /* v3 */ > unchanged > --- > include/linux/fs.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 3cd4fe6b845e..fdc8fb2d786b 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -3651,4 +3651,9 @@ static inline int inode_drain_writes(struct inode *inode) > return filemap_write_and_wait(inode->i_mapping); > } > > +static inline bool is_userns_visible(unsigned long iflags) > +{ > + return (iflags & SB_I_USERNS_VISIBLE); > +} > + > #endif /* _LINUX_FS_H */ > -- > 2.25.0
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