[PATCH] fork.c: Add doc about usage of CLONE_FS flags and namespaces

[Marcos Paulo de Souza]

All other places that deals with namespaces have an explanation of why
the restriction is there. The description added in this commit was based
in e66eded8309eb.

Signed-off-by: Marcos Paulo de Souza <marcos.souza....@gmail.com>
---
 kernel/fork.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/fork.c b/kernel/fork.c
index 07cc743698d3..29cb72b64900 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1549,6 +1549,10 @@ static __latent_entropy struct task_struct *copy_process(
        int retval;
        struct task_struct *p;
 
+       /*
+        * Don't allow sharing the root directory with processes in a different
+        * namespace
+        */
        if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
                return ERR_PTR(-EINVAL);
 
-- 
2.13.6