In message <1256152779-10054-39-git-send-email-vaurora@xxxxxxxxxx>, Valerie Aurora writes: > When moving a union mount, follow it down to the bottom layer and move > that instead of just the top layer. > > Signed-off-by: Valerie Aurora <vaurora@xxxxxxxxxx> > --- > fs/namespace.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/fs/namespace.c b/fs/namespace.c > index 9b71743..6ac5fc1 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -2282,6 +2282,15 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, > if (d_unlinked(old.dentry)) > goto out2; > error = -EBUSY; > + /* > + * follow_union_down() only goes one layer down. We want the > + * bottom-most layer here - if we move that around, all the > + * layers on top move with it. But if we ever allow more than > + * two layers, the below two will both need to be in while() > + * loops. > + */ Given the nature of this comment, I'd stick an "XXX" there for easier ability to grep-the-src-for-issues. > + follow_union_down(&new.mnt, &new.dentry); > + follow_union_down(&root.mnt, &root.dentry); > if (new.mnt == root.mnt || > old.mnt == root.mnt) > goto out2; /* loop, on the same file system */ > -- > 1.6.3.3 > > -- > 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 Erez. -- 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
