Minor comment. Oren Laadan [[email protected]] wrote: | From 0fd2795c29fec51eec75f76ea21394367b6801db Mon Sep 17 00:00:00 2001 | From: Oren Laadan <[email protected]> | Date: Tue, 21 Oct 2008 16:26:10 -0400 | Subject: [PATCH 13/29] External checkpoint of a task other than ourself | | Now we can do "external" checkpoint, i.e. act on another task. | | sys_checkpoint() now looks up the target pid (in our namespace) and | checkpoints that corresponding task. That task should be the root of | a container. | | sys_restart() remains the same, as the restart is always done in the | context of the restarting task. | | Changelog[v14]: | - Refuse non-self checkpoint if target task isn't frozen | | Changelog[v12]: | - Replace obsolete cr_debug() with pr_debug() | | Changelog[v11]: | - Copy contents of 'init->fs->root' instead of pointing to them | | Changelog[v10]: | - Grab vfs root of container init, rather than current process | | Signed-off-by: Oren Laadan <[email protected]> | Acked-by: Serge Hallyn <[email protected]> | --- | checkpoint/checkpoint.c | 73 ++++++++++++++++++++++++++++++++++++++++++- | checkpoint/restart.c | 4 +- | checkpoint/sys.c | 6 +++ | include/linux/checkpoint.h | 2 + | 4 files changed, 81 insertions(+), 4 deletions(-) | | diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c | index d4e0007..25229d3 100644 | --- a/checkpoint/checkpoint.c | +++ b/checkpoint/checkpoint.c | @@ -10,6 +10,8 @@ | | #include <linux/version.h> | #include <linux/sched.h> | +#include <linux/freezer.h> | +#include <linux/ptrace.h> | #include <linux/time.h> | #include <linux/fs.h> | #include <linux/file.h> | @@ -242,6 +244,11 @@ static int cr_write_task(struct cr_ctx *ctx, struct task_struct *t) | { | int ret; | | + if (t->state == TASK_DEAD) { | + pr_warning("c/r: task may not be in state TASK_DEAD\n"); | + return -EAGAIN; | + } | + | ret = cr_write_task_struct(ctx, t); | cr_debug("task_struct: ret %d\n", ret); | if (ret < 0) | @@ -264,22 +271,84 @@ static int cr_write_task(struct cr_ctx *ctx, struct task_struct *t) | return ret; | } | | +static int cr_get_container(struct cr_ctx *ctx, pid_t pid) | +{ | + struct task_struct *task = NULL; | + struct nsproxy *nsproxy = NULL; | + int err = -ESRCH; | + | + ctx->root_pid = pid; | + | + read_lock(&tasklist_lock); | + task = find_task_by_vpid(pid); | + if (task) | + get_task_struct(task); | + read_unlock(&tasklist_lock); | + | + if (!task) | + goto out; | + | +#if 0 /* enable to use containers */ | + if (!is_container_init(task)) { | + err = -EINVAL; | + goto out; | + } | +#endif | + | + if (!ptrace_may_access(task, PTRACE_MODE_READ)) { | + err = -EPERM; | + goto out; | + } | + | + /* verify that the task is frozen (unless self) */ | + if (task != current && !frozen(task)) | + return -EBUSY; | + | + rcu_read_lock(); | + if (task_nsproxy(task)) { | + nsproxy = task_nsproxy(task);
Nit: why call task_nproxy() twice ? | + get_nsproxy(nsproxy); | + } | + rcu_read_unlock(); | + | + if (!nsproxy) | + goto out; Sukadev _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
