From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Louis Rilling <louis.rilling@kerlabs.com>,
Pavel Emelyanov <xemul@openvz.org>,
Linux Containers <containers@lists.osdl.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] procfs: move pid_ns_prepare_proc() from copy_process() to create_pid_namespace()
Date: Sat, 19 Jun 2010 21:10:56 +0200 [thread overview]
Message-ID: <20100619191056.GD3424@redhat.com> (raw)
In-Reply-To: <20100619190840.GA3424@redhat.com>
Imho, pid_ns_prepare_proc() in copy_process() looks very ugly.
Now that pid_ns_prepare_proc()->proc_get_sb() does not depend on the
first alloc_pid(), we can move this code into create_pid_namespace().
This looks much more clean to me, and in theory more correct in case
we ever implement sys_unshare(CLONE_NEWPID).
Note: with or without this patch we have a bug. If CLONE_NEWPID fails
after pid_ns_prepare_proc(), nobody frees ns->proc_mnt. This will be
fixed by the next patches.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
kernel/fork.c | 7 -------
kernel/pid_namespace.c | 10 +++++++++-
2 files changed, 9 insertions(+), 8 deletions(-)
--- 35-rc3/kernel/fork.c~PNS_3_KILL_FORK_MOUNT 2010-06-19 19:20:22.000000000 +0200
+++ 35-rc3/kernel/fork.c 2010-06-19 20:17:35.000000000 +0200
@@ -58,7 +58,6 @@
#include <linux/taskstats_kern.h>
#include <linux/random.h>
#include <linux/tty.h>
-#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/fs_struct.h>
#include <linux/magic.h>
@@ -1154,12 +1153,6 @@ static struct task_struct *copy_process(
pid = alloc_pid(p->nsproxy->pid_ns);
if (!pid)
goto bad_fork_cleanup_io;
-
- if (clone_flags & CLONE_NEWPID) {
- retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
- if (retval < 0)
- goto bad_fork_free_pid;
- }
}
p->pid = pid_nr(pid);
--- 35-rc3/kernel/pid_namespace.c~PNS_3_KILL_FORK_MOUNT 2010-06-19 19:20:22.000000000 +0200
+++ 35-rc3/kernel/pid_namespace.c 2010-06-19 19:21:42.000000000 +0200
@@ -10,6 +10,7 @@
#include <linux/pid.h>
#include <linux/pid_namespace.h>
+#include <linux/proc_fs.h>
#include <linux/syscalls.h>
#include <linux/err.h>
#include <linux/acct.h>
@@ -72,6 +73,7 @@ static struct pid_namespace *create_pid_
{
struct pid_namespace *ns;
unsigned int level = parent_pid_ns->level + 1;
+ int err = -ENOMEM;
int i;
ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL);
@@ -96,14 +98,20 @@ static struct pid_namespace *create_pid_
for (i = 1; i < PIDMAP_ENTRIES; i++)
atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE);
+ err = pid_ns_prepare_proc(ns);
+ if (err)
+ goto out_put_parent;
+
return ns;
+out_put_parent:
+ put_pid_ns(parent_pid_ns);
out_free_map:
kfree(ns->pidmap[0].page);
out_free:
kmem_cache_free(pid_ns_cachep, ns);
out:
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(err);
}
static void destroy_pid_namespace(struct pid_namespace *ns)
next prev parent reply other threads:[~2010-06-19 19:13 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-16 16:34 [PATCH] procfs: Do not release pid_ns->proc_mnt too early Louis Rilling
2010-06-17 9:53 ` Pavel Emelyanov
2010-06-17 13:41 ` Eric W. Biederman
2010-06-17 14:20 ` Louis Rilling
2010-06-17 21:36 ` Oleg Nesterov
2010-06-18 8:27 ` Louis Rilling
2010-06-18 16:27 ` Oleg Nesterov
2010-06-21 11:11 ` Louis Rilling
2010-06-21 12:58 ` Eric W. Biederman
2010-06-21 14:15 ` Louis Rilling
2010-06-21 14:26 ` Eric W. Biederman
2010-06-17 21:20 ` Oleg Nesterov
2010-06-18 8:20 ` Louis Rilling
2010-06-18 11:15 ` Oleg Nesterov
2010-06-18 16:08 ` Oleg Nesterov
2010-06-18 17:33 ` Louis Rilling
2010-06-18 17:55 ` Oleg Nesterov
2010-06-18 21:23 ` Oleg Nesterov
2010-06-19 19:08 ` [PATCH 0/4] pid_ns_prepare_proc/unshare cleanups Oleg Nesterov
2010-06-19 19:09 ` [PATCH 1/4] procfs: proc_get_sb: consolidate/cleanup root_inode->pid logic Oleg Nesterov
2010-06-19 19:10 ` [PATCH 2/4] procfs: kill the global proc_mnt variable Oleg Nesterov
2010-06-19 19:10 ` Oleg Nesterov [this message]
2010-06-19 19:11 ` [PATCH RESEND 4/4] sys_unshare: simplify the not-really-implemented CLONE_THREAD/SIGHAND/VM code Oleg Nesterov
2010-06-20 8:42 ` [PATCH 0/6] Unshare support for the pid namespace Eric W. Biederman
2010-06-20 8:44 ` [PATCH 1/6] pid: Remove the child_reaper special case in init/main.c Eric W. Biederman
2010-06-20 18:29 ` Oleg Nesterov
2010-06-20 20:27 ` Oleg Nesterov
2010-06-20 8:45 ` [PATCH 2/6] pidns: Call pid_ns_prepare_proc from create_pid_namespace Eric W. Biederman
2010-06-20 18:19 ` Oleg Nesterov
2010-06-20 8:45 ` [PATCH 3/6] procfs: kill the global proc_mnt variable Eric W. Biederman
2010-06-20 8:47 ` [PATCH 4/6] pidns: Don't allow new pids after the namespace is dead Eric W. Biederman
2010-06-20 18:44 ` Oleg Nesterov
2010-06-20 8:48 ` [PATCH 5/6] pidns: Use task_active_pid_ns where appropriate Eric W. Biederman
2010-06-20 8:49 ` [PATCH 6/6] pidns: Support unsharing the pid namespace Eric W. Biederman
2010-06-20 20:14 ` Oleg Nesterov
2010-06-20 20:42 ` Oleg Nesterov
2010-06-21 1:53 ` Eric W. Biederman
2010-06-20 18:03 ` [PATCH 0/6] Unshare support for " Oleg Nesterov
2010-06-20 18:05 ` [PATCH 0/2] pid_ns_release_proc() fixes Oleg Nesterov
2010-06-20 18:06 ` [PATCH 1/2] pid_ns: move destroy_pid_namespace() into workqueue context Oleg Nesterov
2010-06-20 18:06 ` [PATCH 2/2] pid_ns: refactor the buggy pid_ns_release_proc() logic Oleg Nesterov
2010-06-20 21:00 ` [PATCH 0/6] Unshare support for the pid namespace Eric W. Biederman
2010-06-20 21:48 ` Oleg Nesterov
2010-06-20 21:56 ` Oleg Nesterov
2011-01-26 15:57 ` Daniel Lezcano
2010-06-23 20:36 ` [PATCH 0/1] pid_ns: move pid_ns_release_proc() from proc_flush_task() to zap_pid_ns_processes() Oleg Nesterov
2010-06-23 20:37 ` [PATCH 1/1] " Oleg Nesterov
2010-06-24 6:36 ` Sukadev Bhattiprolu
2010-06-24 12:59 ` Oleg Nesterov
2010-06-24 7:06 ` Eric W. Biederman
2010-06-24 13:01 ` Oleg Nesterov
2010-06-24 8:37 ` [PATCH] pid_ns: Fix proc_flush_task() accessing freed proc_mnt Louis Rilling
2010-06-24 17:08 ` [RESEND PATCH] " Louis Rilling
2010-06-24 19:18 ` Oleg Nesterov
2010-06-25 10:23 ` Louis Rilling
2010-06-25 12:21 ` Oleg Nesterov
2010-06-25 18:37 ` Sukadev Bhattiprolu
2010-06-25 19:29 ` Oleg Nesterov
2010-06-25 21:26 ` Sukadev Bhattiprolu
2010-06-25 21:27 ` Oleg Nesterov
2010-06-25 22:07 ` Sukadev Bhattiprolu
2010-07-09 4:36 ` [RFC][PATCH 1/2] pidns: Add a flag to indicate a pid namespace is dead Eric W. Biederman
2010-07-09 4:39 ` [RFC][PATCH 2/2] pidns: Remove proc flush races when a pid namespaces are exiting Eric W. Biederman
2010-07-09 12:14 ` Louis Rilling
2010-07-09 13:05 ` Eric W. Biederman
2010-07-09 14:13 ` Louis Rilling
2010-07-09 15:58 ` [PATCH 01/24] pidns: Remove races by stopping the caching of proc_mnt Eric W. Biederman
2010-07-09 22:13 ` Serge E. Hallyn
2010-07-11 14:14 ` Louis Rilling
2010-07-11 14:25 ` Eric W. Biederman
2010-07-12 18:09 ` [PATCH] pidns: Fix wait for zombies to be reaped in zap_pid_ns_processes Eric W. Biederman
2010-07-13 21:42 ` Louis Rilling
2010-07-13 22:34 ` Serge E. Hallyn
2010-07-14 1:47 ` Eric W. Biederman
2010-10-30 7:07 ` Sukadev Bhattiprolu
2010-07-14 20:53 ` Sukadev Bhattiprolu
2010-07-14 21:35 ` Eric W. Biederman
2010-06-21 11:09 ` [PATCH] procfs: Do not release pid_ns->proc_mnt too early Louis Rilling
2010-06-21 11:15 ` Louis Rilling
2010-06-21 14:38 ` Oleg Nesterov
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