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  1. 05 12月, 2014 3 次提交
  3. 10 9月, 2014 1 次提交
  5. 30 7月, 2014 1 次提交
    • E
      namespaces: Use task_lock and not rcu to protect nsproxy · 728dba3a
      由 Eric W. Biederman 提交于 
      The synchronous syncrhonize_rcu in switch_task_namespaces makes setns
a sufficiently expensive system call that people have complained.

Upon inspect nsproxy no longer needs rcu protection for remote reads.
remote reads are rare.  So optimize for same process reads and write
by switching using rask_lock instead.

This yields a simpler to understand lock, and a faster setns system call.

In particular this fixes a performance regression observed
by Rafael David Tinoco <rafael.tinoco@canonical.com>.

This is effectively a revert of Pavel Emelyanov's commit
cf7b708c Make access to task's nsproxy lighter
from 2007.  The race this originialy fixed no longer exists as
do_notify_parent uses task_active_pid_ns(parent) instead of
parent->nsproxy.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      728dba3a
  7. 16 5月, 2014 1 次提交
  9. 27 4月, 2014 1 次提交
  11. 31 8月, 2013 1 次提交
  13. 02 5月, 2013 1 次提交
  15. 23 2月, 2013 1 次提交
  17. 15 12月, 2012 1 次提交
    • E
      userns: Require CAP_SYS_ADMIN for most uses of setns. · 5e4a0847
      由 Eric W. Biederman 提交于 
      Andy Lutomirski <luto@amacapital.net> found a nasty little bug in
the permissions of setns.  With unprivileged user namespaces it
became possible to create new namespaces without privilege.

However the setns calls were relaxed to only require CAP_SYS_ADMIN in
the user nameapce of the targed namespace.

Which made the following nasty sequence possible.

pid = clone(CLONE_NEWUSER | CLONE_NEWNS);
if (pid == 0) { /* child */
	system("mount --bind /home/me/passwd /etc/passwd");
}
else if (pid != 0) { /* parent */
	char path[PATH_MAX];
	snprintf(path, sizeof(path), "/proc/%u/ns/mnt");
	fd = open(path, O_RDONLY);
	setns(fd, 0);
	system("su -");
}

Prevent this possibility by requiring CAP_SYS_ADMIN
in the current user namespace when joing all but the user namespace.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      5e4a0847
  19. 20 11月, 2012 2 次提交
    • E
      proc: Usable inode numbers for the namespace file descriptors. · 98f842e6
      由 Eric W. Biederman 提交于 
      Assign a unique proc inode to each namespace, and use that
inode number to ensure we only allocate at most one proc
inode for every namespace in proc.

A single proc inode per namespace allows userspace to test
to see if two processes are in the same namespace.

This has been a long requested feature and only blocked because
a naive implementation would put the id in a global space and
would ultimately require having a namespace for the names of
namespaces, making migration and certain virtualization tricks
impossible.

We still don't have per superblock inode numbers for proc, which
appears necessary for application unaware checkpoint/restart and
migrations (if the application is using namespace file descriptors)
but that is now allowd by the design if it becomes important.

I have preallocated the ipc and uts initial proc inode numbers so
their structures can be statically initialized.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      98f842e6
    • E
      userns: Allow unprivileged use of setns. · 142e1d1d
      由 Eric W. Biederman 提交于 
      - Push the permission check from the core setns syscall into
  the setns install methods where the user namespace of the
  target namespace can be determined, and used in a ns_capable
  call.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      142e1d1d
  21. 19 11月, 2012 4 次提交
  23. 19 7月, 2012 1 次提交
  25. 17 5月, 2012 1 次提交
  27. 18 4月, 2012 1 次提交
  29. 27 1月, 2012 1 次提交
    • E
      netns: fix net_alloc_generic() · 073862ba
      由 Eric Dumazet 提交于 
      When a new net namespace is created, we should attach to it a "struct
net_generic" with enough slots (even empty), or we can hit the following
BUG_ON() :

[  200.752016] kernel BUG at include/net/netns/generic.h:40!
...
[  200.752016]  [<ffffffff825c3cea>] ? get_cfcnfg+0x3a/0x180
[  200.752016]  [<ffffffff821cf0b0>] ? lockdep_rtnl_is_held+0x10/0x20
[  200.752016]  [<ffffffff825c41be>] caif_device_notify+0x2e/0x530
[  200.752016]  [<ffffffff810d61b7>] notifier_call_chain+0x67/0x110
[  200.752016]  [<ffffffff810d67c1>] raw_notifier_call_chain+0x11/0x20
[  200.752016]  [<ffffffff821bae82>] call_netdevice_notifiers+0x32/0x60
[  200.752016]  [<ffffffff821c2b26>] register_netdevice+0x196/0x300
[  200.752016]  [<ffffffff821c2ca9>] register_netdev+0x19/0x30
[  200.752016]  [<ffffffff81c1c67a>] loopback_net_init+0x4a/0xa0
[  200.752016]  [<ffffffff821b5e62>] ops_init+0x42/0x180
[  200.752016]  [<ffffffff821b600b>] setup_net+0x6b/0x100
[  200.752016]  [<ffffffff821b6466>] copy_net_ns+0x86/0x110
[  200.752016]  [<ffffffff810d5789>] create_new_namespaces+0xd9/0x190

net_alloc_generic() should take into account the maximum index into the
ptr array, as a subsystem might use net_generic() anytime.

This also reduces number of reallocations in net_assign_generic()
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Tested-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Sjur Brændeland <sjur.brandeland@stericsson.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      073862ba
  31. 01 11月, 2011 1 次提交
  33. 02 7月, 2011 1 次提交
    • T
      rtnl: provide link dump consistency info · 4e985ada
      由 Thomas Graf 提交于 
      This patch adds a change sequence counter to each net namespace
which is bumped whenever a netdevice is added or removed from
the list. If such a change occurred while a link dump took place,
the dump will have the NLM_F_DUMP_INTR flag set in the first
message which has been interrupted and in all subsequent messages
of the same dump.

Note that links may still be modified or renamed while a dump is
taking place but we can guarantee for userspace to receive a
complete list of links and not miss any.

Testing:
I have added 500 VLAN netdevices to make sure the dump is split
over multiple messages. Then while continuously dumping links in
one process I also continuously deleted and re-added a dummy
netdevice in another process. Multiple dumps per seconds have
had the NLM_F_DUMP_INTR flag set.

I guess we can wait for Johannes patch to hit net-next via the
wireless tree.  I just wanted to give this some testing right away.
Signed-off-by: NThomas Graf <tgraf@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4e985ada
  35. 13 6月, 2011 1 次提交
    • A
      Delay struct net freeing while there's a sysfs instance refering to it · a685e089
      由 Al Viro 提交于 
      	* new refcount in struct net, controlling actual freeing of the memory
	* new method in kobj_ns_type_operations (->drop_ns())
	* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns().  For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped.  Method renamed to ->grab_current_ns().
	* old net_free() callers call net_drop_ns() instead.
	* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL.  That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.

	Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called.  The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      a685e089
  37. 06 6月, 2011 1 次提交
  39. 25 5月, 2011 1 次提交
  41. 11 5月, 2011 2 次提交
  43. 08 5月, 2011 1 次提交
  45. 16 4月, 2011 1 次提交
  47. 26 10月, 2010 1 次提交
  49. 28 4月, 2010 1 次提交
  51. 25 4月, 2010 1 次提交
  53. 04 12月, 2009 3 次提交
  55. 02 12月, 2009 2 次提交
    • E
      net: Automatically allocate per namespace data. · f875bae0
      由 Eric W. Biederman 提交于 
      To get the full benefit of batched network namespace cleanup netowrk
device deletion needs to be performed by the generic code.  When
using register_pernet_gen_device and freeing the data in exit_net
it is impossible to delay allocation until after exit_net has called
as the device uninit methods are no longer safe.

To correct this, and to simplify working with per network namespace data
I have moved allocation and deletion of per network namespace data into
the network namespace core.  The core now frees the data only after
all of the network namespace exit routines have run.

Now it is only required to set the new fields .id and .size
in the pernet_operations structure if you want network namespace
data to be managed for you automatically.

This makes the current register_pernet_gen_device and
register_pernet_gen_subsys routines unnecessary.  For the moment
I have left them as compatibility wrappers in net_namespace.h
They will be removed once all of the users have been updated.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f875bae0
    • E
      net: Batch network namespace destruction. · 2b035b39
      由 Eric W. Biederman 提交于 
      It is fairly common to kill several network namespaces at once.  Either
because they are nested one inside the other or because they are cooperating
in multiple machine networking experiments.  As the network stack control logic
does not parallelize easily batch up multiple network namespaces existing
together.

To get the full benefit of batching the virtual network devices to be
removed must be all removed in one batch.  For that purpose I have added
a loop after the last network device operations have run that batches
up all remaining network devices and deletes them.

An extra benefit is that the reorganization slightly shrinks the size
of the per network namespace data structures replaceing a work_struct
with a list_head.

In a trivial test with 4K namespaces this change reduced the cost of
a destroying 4K namespaces from 7+ minutes (at 12% cpu) to 44 seconds
(at 60% cpu).  The bulk of that 44s was spent in inet_twsk_purge.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2b035b39
  57. 26 11月, 2009 1 次提交
  59. 03 8月, 2009 1 次提交