Hi, This is V2 of patches. Fixed the function format issue and also I was using CONFIG_CGROUP instead of CONFIG_CGROUPS. That led to crash at boot. Fixed that. Some applications like sssd want to know the cgroup of connected peer over unix stream socket. They want to use this information to map the cgroup to the container client belongs to and then decide what kind of policies apply on the container. Well why not use SO_PEERCRED, extract pid from it and lookup in /proc/pid/cgroup to figure out cgroup of client. Problem there is that it is racy. By the time we look up in /proc, it might happen that client exited (possibly after handing over socket fd to a child), and client pid can possibly be assigned to another process. That's the reason people are looking for more reliable mechanism. There are others like journald who want similar information over unix datagram sockets. A patchset to provide that functionality was posted here. https://lkml.org/lkml/2014/1/13/43 But this was rejected because of overhead it will cause for rest of the cases. https://lkml.org/lkml/2014/1/15/480 This patch series implements SO_PEERCGROUP, which gives the cgroup of client at the time of opening the connection. So overhead is involved only during connection setup and there should not be any overhead after that. So it does not solve all the use cases out there but can solve the needs of sssd. Hence I am posting this patch. Please consider it for inclusion. Thanks Vivek Vivek Goyal (2): cgroup: Provide empty definition of task_cgroup_path() net: Implement SO_PEERCGROUP arch/alpha/include/uapi/asm/socket.h | 1 + arch/avr32/include/uapi/asm/socket.h | 1 + arch/cris/include/uapi/asm/socket.h | 2 ++ arch/frv/include/uapi/asm/socket.h | 1 + arch/ia64/include/uapi/asm/socket.h | 2 ++ arch/m32r/include/uapi/asm/socket.h | 1 + arch/mips/include/uapi/asm/socket.h | 1 + arch/mn10300/include/uapi/asm/socket.h | 1 + arch/parisc/include/uapi/asm/socket.h | 1 + arch/powerpc/include/uapi/asm/socket.h | 1 + arch/s390/include/uapi/asm/socket.h | 1 + arch/sparc/include/uapi/asm/socket.h | 2 ++ arch/xtensa/include/uapi/asm/socket.h | 1 + include/linux/cgroup.h | 6 +++++ include/net/sock.h | 1 + include/uapi/asm-generic/socket.h | 2 ++ net/core/sock.c | 19 ++++++++++++++ net/unix/af_unix.c | 48 ++++++++++++++++++++++++++++++++++ 18 files changed, 92 insertions(+) -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
