[REVIEW][PATCH 0/4] /proc/thread-self

This patchset implements /proc/thread-self a magic symlink that
solves a couple of problems.

- It makes it easy to get to a specific threads directory in /proc
  with gettid() not being exported in glibc this is currently a pain.

- It allows fixing the problem present in /proc/mounts and /proc/net
  that when the thread group leader exits but the entire thread group
  remains /proc/self/net and /proc/self/mounts and thus /proc/mounts and
  /proc/net become empty.

- As mount and network namespaces are per thread it allows /proc/net and
  /proc/mounts to reflect this.

This is small chance changing /proc/net and /proc/mounts will cause
userspace regressions (although nothing has shown up in my testing) if
that happens we can just point the change that moves them from
/proc/self/... to /proc/thread-self/...

Eric W. Biederman (4):
      proc: Have net show up under /proc/<tgid>/task/<tid>
      proc: Implement /proc/thread-self to point at the directory of the current thread
      proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net
      proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts

 fs/proc/Makefile              |  1 +
 fs/proc/base.c                | 18 ++++++---
 fs/proc/inode.c               |  7 +++-
 fs/proc/internal.h            |  6 +++
 fs/proc/proc_net.c            |  2 +-
 fs/proc/root.c                |  5 ++-
 fs/proc/thread_self.c         | 85 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/pid_namespace.h |  1 +
 8 files changed, 117 insertions(+), 8 deletions(-)

Eric

On 07/31/14 17:30, Eric W. Biederman wrote:

This patchset implements /proc/thread-self a magic symlink that
solves a couple of problems.

- It makes it easy to get to a specific threads directory in /proc
  with gettid() not being exported in glibc this is currently a pain.

- It allows fixing the problem present in /proc/mounts and /proc/net
  that when the thread group leader exits but the entire thread group
  remains /proc/self/net and /proc/self/mounts and thus /proc/mounts and
  /proc/net become empty.

- As mount and network namespaces are per thread it allows /proc/net and
  /proc/mounts to reflect this.

Hi Eric,

Any changes/additions to Documentation/ ?

Thanks.

This is small chance changing /proc/net and /proc/mounts will cause
userspace regressions (although nothing has shown up in my testing) if
that happens we can just point the change that moves them from
/proc/self/... to /proc/thread-self/...

Eric W. Biederman (4):
      proc: Have net show up under /proc/<tgid>/task/<tid>
      proc: Implement /proc/thread-self to point at the directory of the current thread
      proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net
      proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts

 fs/proc/Makefile              |  1 +
 fs/proc/base.c                | 18 ++++++---
 fs/proc/inode.c               |  7 +++-
 fs/proc/internal.h            |  6 +++
 fs/proc/proc_net.c            |  2 +-
 fs/proc/root.c                |  5 ++-
 fs/proc/thread_self.c         | 85 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/pid_namespace.h |  1 +
 8 files changed, 117 insertions(+), 8 deletions(-)

-- 
~Randy

ebiederm@xmission.com (Eric W. Biederman)
writes:

This patchset implements /proc/thread-self a magic symlink that
solves a couple of problems.

- It makes it easy to get to a specific threads directory in /proc
  with gettid() not being exported in glibc this is currently a pain.

syscall(__NR_gettid);

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only