From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 30 Mar 2009 11:20:30 +0000 (-0400)
Subject: New locking/refcounting for fs_struct
X-Git-Tag: v2.6.30-rc1~244^2~9
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=498052bba55ecaff58db6a1436b0e25bfd75a7ff;p=pandora-kernel.git

New locking/refcounting for fs_struct

* all changes of current->fs are done under task_lock and write_lock of
  old fs->lock
* refcount is not atomic anymore (same protection)
* its decrements are done when removing reference from current; at the
  same time we decide whether to free it.
* put_fs_struct() is gone
* new field - ->in_exec.  Set by check_unsafe_exec() if we are trying to do
  execve() and only subthreads share fs_struct.  Cleared when finishing exec
  (success and failure alike).  Makes CLONE_FS fail with -EAGAIN if set.
* check_unsafe_exec() may fail with -EAGAIN if another execve() from subthread
  is in progress.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

Reading git-diff-tree failed