Add the interface to handle pids as proper c/r shared objects. This
is the first step in converting the c/r code to hanlde pid as pids
objects that are namespace aware. Also remote the unused field
@root_pid from struct ckpt_ctx.
Signed-off-by: Oren Laadan <or...@cs.columbia.edu>
---
include/linux/checkpoint_hdr.h | 6 +++++-
include/linux/checkpoint_types.h | 1 -
kernel/checkpoint/checkpoint.c | 2 --
kernel/checkpoint/restart.c | 1 -
kernel/pid.c | 28 ++++++++++++++++++++++++++++
5 files changed, 33 insertions(+), 5 deletions(-)
diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
index b12d586..922eff0 100644
--- a/include/linux/checkpoint_hdr.h
+++ b/include/linux/checkpoint_hdr.h
@@ -245,6 +245,8 @@ struct ckpt_hdr_objref {
enum obj_type {
CKPT_OBJ_IGNORE = 0,
#define CKPT_OBJ_IGNORE CKPT_OBJ_IGNORE
+ CKPT_OBJ_PID,
+#define CKPT_OBJ_PID CKPT_OBJ_PID
CKPT_OBJ_INODE,
#define CKPT_OBJ_INODE CKPT_OBJ_INODE
CKPT_OBJ_FILE_TABLE,
@@ -373,7 +375,9 @@ struct ckpt_pids {
} __attribute__((aligned(8)));
/* pids */
-#define CKPT_PID_NULL -1
+/* (negative but not valid error) */
+#define CKPT_PID_NULL (-4096) /* null pid pointer */
+#define CKPT_PID_ROOT (-4097) /* pid same as root task */
/* task data */
struct ckpt_hdr_task {
diff --git a/include/linux/checkpoint_types.h b/include/linux/checkpoint_types.h
index cf74d3e..87a569a 100644
--- a/include/linux/checkpoint_types.h
+++ b/include/linux/checkpoint_types.h
@@ -35,7 +35,6 @@ struct ckpt_ctx {
ktime_t ktime_begin; /* operation start time */
int root_init; /* [container] root init ? */
- pid_t root_pid; /* [container] root pid */
struct task_struct *root_task; /* [container] root task */
struct nsproxy *root_nsproxy; /* [container] root nsproxy */
struct task_struct *root_freezer; /* [container] root task */
diff --git a/kernel/checkpoint/checkpoint.c b/kernel/checkpoint/checkpoint.c
index 01653d7..a850423 100644
--- a/kernel/checkpoint/checkpoint.c
+++ b/kernel/checkpoint/checkpoint.c
@@ -628,8 +628,6 @@ static int init_checkpoint_ctx(struct ckpt_ctx *ctx, pid_t
pid)
* occurs then ckpt_ctx_free() is eventually called.
*/
- ctx->root_pid = pid;
-
/* root task */
rcu_read_lock();
task = find_task_by_vpid(pid);
diff --git a/kernel/checkpoint/restart.c b/kernel/checkpoint/restart.c
index 66b6625..9aaab4f 100644
--- a/kernel/checkpoint/restart.c
+++ b/kernel/checkpoint/restart.c
@@ -1178,7 +1178,6 @@ static struct task_struct *choose_root_task(struct
ckpt_ctx *ctx, pid_t pid)
struct task_struct *task;
if (ctx->uflags & RESTART_TASKSELF) {
- ctx->root_pid = pid;
ctx->root_task = current;
get_task_struct(current);
return current;
diff --git a/kernel/pid.c b/kernel/pid.c
index f08f40a..0269991 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -36,6 +36,7 @@
#include <linux/pid_namespace.h>
#include <linux/init_task.h>
#include <linux/syscalls.h>
+#include <linux/checkpoint.h>
#define pid_hashfn(nr, ns) \
hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
@@ -571,6 +572,30 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return pid;
}
+#ifdef CONFIG_CHECKPOINT
+
+/* pid-related checkpoint objects */
+
+static int obj_pid_grab(void *ptr)
+{
+ get_pid((struct pid *) ptr);
+ return 0;
+}
+
+static void obj_pid_drop(void *ptr, int lastref)
+{
+ put_pid((struct pid *) ptr);
+}
+
+static const struct ckpt_obj_ops ckpt_obj_pid_ops = {
+ .obj_name = "PID",
+ .obj_type = CKPT_OBJ_PID,
+ .ref_drop = obj_pid_drop,
+ .ref_grab = obj_pid_grab,
+};
+
+#endif /* CONFIG_CHECKPOINT */
+
/*
* The pid hash table is scaled according to the amount of memory in the
* machine. From a minimum of 16 slots up to 4096 slots at one gigabyte or
@@ -605,4 +630,7 @@ void __init pidmap_init(void)
init_pid_ns.pid_cachep = KMEM_CACHE(pid,
SLAB_HWCACHE_ALIGN | SLAB_PANIC);
+#ifdef CONFIG_CHECKPOINT
+ register_checkpoint_obj(&ckpt_obj_pid_ops);
+#endif
}
--
1.7.1
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