linux-stable.git/include/linux/init_task.h, branch linux-2.6.24.y

Isolate the explicit usage of signal->pgrp

2007-10-19T18:53:43+00:00

The pgrp field is not used widely around the kernel so it is now marked as
deprecated with appropriate comment.

The initialization of INIT_SIGNALS is trimmed because
a) they are set to 0 automatically;
b) gcc cannot properly initialize two anonymous (the second one
   is the one with the session) unions. In this particular case
   to make it compile we'd have to add some field initialized
   right before the .pgrp.

This is the same patch as the 1ec320afdc9552c92191d5f89fcd1ebe588334ca one
(from Cedric), but for the pgrp field.

Some progress report:

We have to deprecate the pid, tgid, session and pgrp fields on struct
task_struct and struct signal_struct.  The session and pgrp are already
deprecated.  The tgid value is close to being such - the worst known usage
in in fs/locks.c and audit code.  The pid field deprecation is mainly
blocked by numerous printk-s around the kernel that print the tsk->pid to
log.

Signed-off-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: Sukadev Bhattiprolu 
Cc: Cedric Le Goater 
Cc: Serge Hallyn 
Cc: "Eric W. Biederman" 
Cc: Herbert Poetzl 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pid namespaces: remove the struct pid unneeded fields

2007-10-19T18:53:40+00:00

Since we've switched from using pid->nr to pid->upids->nr some
fields on struct pid are no longer needed

Signed-off-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: Sukadev Bhattiprolu 
Cc: Paul Menage 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pid namespaces: introduce struct upid

2007-10-19T18:53:38+00:00

Since task will be visible from different pid namespaces each of them have to
be addressed by multiple pids.  struct upid is to store the information about
which id refers to which namespace.

The constuciton looks like this.  Each struct pid carried the reference
counter and the list of tasks attached to this pid.  At its end it has a
variable length array of struct upid-s.  Each struct upid has a numerical id
(pid itself), pointer to the namespace, this ID is valid in and is hashed into
a pid_hash for searching the pids.

The nr and pid_chain fields are kept in struct pid for a while to make kernel
still work (no patch initialize the upids yet), but it will be removed at the
end of this series when we switch to upids completely.

Signed-off-by: Sukadev Bhattiprolu 
Signed-off-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: Paul Menage 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove unused member from nsproxy

2007-10-17T15:42:59+00:00

The nslock spinlock is not used in the kernel at all.  Remove it.

Signed-off-by: Pavel Emelyanov 
Acked-by: Serge Hallyn 
Cc: Cedric Le Goater 
Cc: "Eric W. Biederman" 
Cc: Herbert Poetzl 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: dirty balancing for tasks

2007-10-17T15:42:45+00:00

Based on ideas of Andrew:
  http://marc.info/?l=linux-kernel&m=102912915020543&w=2

Scale the bdi dirty limit inversly with the tasks dirty rate.
This makes heavy writers have a lower dirty limit than the occasional writer.

Andrea proposed something similar:
  http://lwn.net/Articles/152277/

The main disadvantage to his patch is that he uses an unrelated quantity to
measure time, which leaves him with a workload dependant tunable. Other than
that the two approaches appear quite similar.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[NETNS]: Fix allnoconfig compilation error.

2007-10-10T23:49:21+00:00

When CONFIG_NET=no, init_net is unresolved because net_namespace.c
is not compiled and the include pull init_net definition.

This problem was very similar with the ipc namespace where the kernel
can be compiled with SYSV ipc out.

This patch fix that defining a macro which simply remove init_net
initialization from nsproxy namespace aggregator.

Compiled and booted on qemu-i386 with CONFIG_NET=no and CONFIG_NET=yes.

Signed-off-by: Daniel Lezcano 
Acked-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

[NET]: Add a network namespace parameter to tasks

2007-10-10T23:49:04+00:00

This is the network namespace from which all which all sockets
and anything else under user control ultimately get their network
namespace parameters.

Signed-off-by: Eric W. Biederman 
Signed-off-by: David S. Miller

signalfd simplification

2007-09-20T20:19:59+00:00

This simplifies signalfd code, by avoiding it to remain attached to the
sighand during its lifetime.

In this way, the signalfd remain attached to the sighand only during
poll(2) (and select and epoll) and read(2).  This also allows to remove
all the custom "tsk == current" checks in kernel/signal.c, since
dequeue_signal() will only be called by "current".

I think this is also what Ben was suggesting time ago.

The external effect of this, is that a thread can extract only its own
private signals and the group ones.  I think this is an acceptable
behaviour, in that those are the signals the thread would be able to
fetch w/out signalfd.

Signed-off-by: Davide Libenzi 
Signed-off-by: Linus Torvalds

user namespace: add the framework

2007-07-16T16:05:47+00:00

Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.

A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)

The unshare is not included in this patch.

Changes since [try #4]:
	- Updated get_user_ns and put_user_ns to accept NULL, and
	  get_user_ns to return the namespace.

Changes since [try #3]:
	- moved struct user_namespace to files user_namespace.{c,h}

Changes since [try #2]:
	- removed struct user_namespace* argument from find_user()

Changes since [try #1]:
	- removed struct user_namespace* argument from find_user()
	- added a root_user per user namespace

Signed-off-by: Cedric Le Goater 
Signed-off-by: Serge E. Hallyn 
Acked-by: Pavel Emelianov 
Cc: Herbert Poetzl 
Cc: Kirill Korotaev 
Cc: Eric W. Biederman 
Cc: Chris Wright 
Cc: Stephen Smalley 
Cc: James Morris 
Cc: Andrew Morgan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal/timer/event: signalfd core

2007-05-11T15:29:36+00:00

This patch series implements the new signalfd() system call.

I took part of the original Linus code (and you know how badly it can be
broken :), and I added even more breakage ;) Signals are fetched from the same
signal queue used by the process, so signalfd will compete with standard
kernel delivery in dequeue_signal().  If you want to reliably fetch signals on
the signalfd file, you need to block them with sigprocmask(SIG_BLOCK).  This
seems to be working fine on my Dual Opteron machine.  I made a quick test
program for it:

http://www.xmailserver.org/signafd-test.c

The signalfd() system call implements signal delivery into a file descriptor
receiver.  The signalfd file descriptor if created with the following API:

int signalfd(int ufd, const sigset_t *mask, size_t masksize);

The "ufd" parameter allows to change an existing signalfd sigmask, w/out going
to close/create cycle (Linus idea).  Use "ufd" == -1 if you want a brand new
signalfd file.

The "mask" allows to specify the signal mask of signals that we are interested
in.  The "masksize" parameter is the size of "mask".

The signalfd fd supports the poll(2) and read(2) system calls.  The poll(2)
will return POLLIN when signals are available to be dequeued.  As a direct
consequence of supporting the Linux poll subsystem, the signalfd fd can use
used together with epoll(2) too.

The read(2) system call will return a "struct signalfd_siginfo" structure in
the userspace supplied buffer.  The return value is the number of bytes copied
in the supplied buffer, or -1 in case of error.  The read(2) call can also
return 0, in case the sighand structure to which the signalfd was attached,
has been orphaned.  The O_NONBLOCK flag is also supported, and read(2) will
return -EAGAIN in case no signal is available.

If the size of the buffer passed to read(2) is lower than sizeof(struct
signalfd_siginfo), -EINVAL is returned.  A read from the signalfd can also
return -ERESTARTSYS in case a signal hits the process.  The format of the
struct signalfd_siginfo is, and the valid fields depends of the (->code &
__SI_MASK) value, in the same way a struct siginfo would:

struct signalfd_siginfo {
	__u32 signo;	/* si_signo */
	__s32 err;	/* si_errno */
	__s32 code;	/* si_code */
	__u32 pid;	/* si_pid */
	__u32 uid;	/* si_uid */
	__s32 fd;	/* si_fd */
	__u32 tid;	/* si_fd */
	__u32 band;	/* si_band */
	__u32 overrun;	/* si_overrun */
	__u32 trapno;	/* si_trapno */
	__s32 status;	/* si_status */
	__s32 svint;	/* si_int */
	__u64 svptr;	/* si_ptr */
	__u64 utime;	/* si_utime */
	__u64 stime;	/* si_stime */
	__u64 addr;	/* si_addr */
};

[akpm@linux-foundation.org: fix signalfd_copyinfo() on i386]
Signed-off-by: Davide Libenzi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds