[PATCH RFC v3 87/90] cells: add CONFIG_CELLS

[Josef Bacik]

Everything is in place now. Add the config symbol, and build kernel/cell/,
kernel/embryo.c and fs/cellfs.c if it is set.

Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
 fs/Makefile     |  2 ++
 init/Kconfig    | 16 ++++++++++++++++
 kernel/Makefile |  1 +
 3 files changed, 19 insertions(+)

diff --git a/fs/Makefile b/fs/Makefile
index 16f1108b64e1..6a15893003e3 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -127,3 +127,5 @@ obj-$(CONFIG_VBOXSF_FS)		+= vboxsf/
 obj-$(CONFIG_ZONEFS_FS)		+= zonefs/
 obj-$(CONFIG_BPF_LSM)		+= bpf_fs_kfuncs.o
 obj-$(CONFIG_RESCTRL_FS)	+= resctrl/
+
+obj-$(CONFIG_CELLS)		+= cellfs.o
diff --git a/init/Kconfig b/init/Kconfig
index 4013781e0a02..78690b74e6cb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1264,6 +1264,22 @@ config USER_NS_MAP_KUNIT_TEST
 
 	  If unsure, say N.
 
+config CELLS
+	bool "Cells"
+	depends on USER_NS && PID_NS && NET_NS && IPC_NS && UTS_NS && CGROUPS
+	depends on UNIX
+	help
+	  A cell is a container as one kernel object. It is built from the
+	  outside by filling slots from file descriptors, sealed, and has
+	  tasks spawned into it. A task never changes cell and nothing can
+	  enter one.
+
+	  This reserves the upper half of the uid and gid space for the
+	  kernel to hand out to cells: with it enabled no file on a filesystem
+	  of the host can be given to an id from 2147483648 to 4294901759.
+
+	  If unsure, say N.
+
 config PID_NS
 	bool "PID Namespaces"
 	default y
diff --git a/kernel/Makefile b/kernel/Makefile
index da712b4399ff..ba60039affdb 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -90,6 +90,7 @@ obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_CGROUPS) += cgroup/
 obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_USER_NS) += user_namespace.o
+obj-$(CONFIG_CELLS) += cell/ embryo.o
 obj-$(CONFIG_PID_NS) += pid_namespace.o
 obj-$(CONFIG_IKCONFIG) += configs.o
 obj-$(CONFIG_IKHEADERS) += kheaders.o

-- 
2.55.0