linux/include
Stanislav Kinsbursky 4a674f34ba ipc: introduce message queue copy feature
This patch is required for checkpoint/restore in userspace.

c/r requires some way to get all pending IPC messages without deleting
them from the queue (checkpoint can fail and in this case tasks will be
resumed, so queue have to be valid).

To achive this, new operation flag MSG_COPY for sys_msgrcv() system call
was introduced.  If this flag was specified, then mtype is interpreted as
number of the message to copy.

If MSG_COPY is set, then kernel will allocate dummy message with passed
size, and then use new copy_msg() helper function to copy desired message
(instead of unlinking it from the queue).

Notes:

1) Return -ENOSYS if MSG_COPY is specified, but
   CONFIG_CHECKPOINT_RESTORE is not set.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:45 -08:00
..
acpi PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
asm-generic include: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
clocksource
crypto crypto: cast5/cast6 - move lookup tables to shared module 2012-12-06 17:16:26 +08:00
drm Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2012-12-30 13:54:12 +10:00
keys
linux ipc: message queue receive cleanup 2013-01-04 16:11:45 -08:00
math-emu
media
memory
misc
net netprio_cgroup: define sk_cgrp_prioidx only if NETPRIO_CGROUP is enabled 2012-12-26 14:16:23 -08:00
pcmcia
ras
rdma UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00
target target/iscsi_target: Add NodeACL tags for initiator group support 2012-12-13 14:18:09 -08:00
trace Various bug fixes for ext4. Perhaps the most serious bug fixed is one 2013-01-02 09:57:34 -08:00
uapi ipc: introduce message queue copy feature 2013-01-04 16:11:45 -08:00
video Merge branch 'omap-for-v3.8/fixes-for-merge-window' into omap-for-v3.8/fixes-for-merge-window-v2 2012-12-16 11:28:10 -08:00
xen Bugfixes: 2012-12-18 12:26:54 -08:00
Kbuild UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00