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author | Serge E. Hallyn <serue@us.ibm.com> | 2007-10-19 08:39:45 +0200 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 20:53:37 +0200 |
commit | 858d72ead4864da0fb0b89b919524125ce998e27 (patch) | |
tree | 19ea321ca3b505efecb2053a829daf89a6a22529 /kernel/nsproxy.c | |
parent | Add cgroupstats (diff) | |
download | linux-858d72ead4864da0fb0b89b919524125ce998e27.tar.xz linux-858d72ead4864da0fb0b89b919524125ce998e27.zip |
cgroups: implement namespace tracking subsystem
When a task enters a new namespace via a clone() or unshare(), a new cgroup
is created and the task moves into it.
This version names cgroups which are automatically created using
cgroup_clone() as "node_<pid>" where pid is the pid of the unsharing or
cloned process. (Thanks Pavel for the idea) This is safe because if the
process unshares again, it will create
/cgroups/(...)/node_<pid>/node_<pid>
The only possibilities (AFAICT) for a -EEXIST on unshare are
1. pid wraparound
2. a process fails an unshare, then tries again.
Case 1 is unlikely enough that I ignore it (at least for now). In case 2, the
node_<pid> will be empty and can be rmdir'ed to make the subsequent unshare()
succeed.
Changelog:
Name cloned cgroups as "node_<pid>".
[clg@fr.ibm.com: fix order of cgroup subsystems in init/Kconfig]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r-- | kernel/nsproxy.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 049e7c0ac566..ac99837e7a04 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -156,7 +156,14 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) goto out; } + err = ns_cgroup_clone(tsk); + if (err) { + put_nsproxy(new_ns); + goto out; + } + tsk->nsproxy = new_ns; + out: put_nsproxy(old_ns); return err; @@ -196,8 +203,16 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, *new_nsp = create_new_namespaces(unshare_flags, current, new_fs ? new_fs : current->fs); - if (IS_ERR(*new_nsp)) + if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); + goto out; + } + + err = ns_cgroup_clone(current); + if (err) + put_nsproxy(*new_nsp); + +out: return err; } |