• Christian Brauner's avatar
    nsproxy: add struct nsset · f2a8d52e
    Christian Brauner authored
    Add a simple struct nsset. It holds all necessary pieces to switch to a new
    set of namespaces without leaving a task in a half-switched state which we
    will make use of in the next patch. This patch switches the existing setns
    logic over without causing a change in setns() behavior. This brings
    setns() closer to how unshare() works(). The prepare_ns() function is
    responsible to prepare all necessary information. This has two reasons.
    First it minimizes dependencies between individual namespaces, i.e. all
    install handler can expect that all fields are properly initialized
    independent in what order they are called in. Second, this makes the code
    easier to maintain and easier to follow if it needs to be changed.
    
    The prepare_ns() helper will only be switched over to use a flags argument
    in the next patch. Here it will still use nstype as a simple integer
    argument which was argued would be clearer. I'm not particularly
    opinionated about this if it really helps or not. The struct nsset itself
    already contains the flags field since its name already indicates that it
    can contain information required by different namespaces. None of this
    should have functional consequences.
    Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
    Reviewed-by: default avatarSerge Hallyn <serge@hallyn.com>
    Cc: Eric W. Biederman <ebiederm@xmission.com>
    Cc: Serge Hallyn <serge@hallyn.com>
    Cc: Jann Horn <jannh@google.com>
    Cc: Michael Kerrisk <mtk.manpages@gmail.com>
    Cc: Aleksa Sarai <cyphar@cyphar.com>
    Link: https://lore.kernel.org/r/20200505140432.181565-2-christian.brauner@ubuntu.com
    f2a8d52e
namespace.c 4.59 KB