On Tue, Mar 8, 2016 at 1:16 AM, Alexander Larsson <alexl@xxxxxxxxxx> wrote: > On mån, 2016-03-07 at 20:59 -0800, Andy Lutomirski wrote: >> On Thu, May 28, 2015 at 12:42 PM, Eric W. Biederman >> <ebiederm@xxxxxxxxxxxx> wrote: >> > Andy Lutomirski <luto@xxxxxxxxxxxxxx> writes: >> > >> Apparently alexl is encountering some annoyances related to the >> current workaround, and the workaround is certainly ugly. > > It works, but it introduces an extra namespace that gets exposed to the > world, which is pretty ugly. For instance, entering the namespace > becomes hard. I can setns() into the intermediate user+mount namespace > without problems, but if i try to setns into the final user+mount ns > (it gets its own implicit mount ns) i get EPERM. I'm not sure exactly > why though... > >> Your proposal seems like it could break some use cases involving >> fscaps on a mount or mount-like binary. >> >> What if we change it to use the owner of the userns that owns the >> current mount ns? For anything that doesn't explicitly use >> namespaces, this will be zero. For namespace users, it should do the >> right thing. > > Any of these is fine with me. One nice thing would if i could somehow > detect whether this was supported or not so that i can fall back on the > old workaround. I'll send a patch. I suppose the straightforward, if slightly awkward, way to detect it is just to try it -- create a namespace and try to mount devpts. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
