[PATCH] sanitize unshare_files/reset_files_struct

* let unshare_files() give caller the displaced files_struct
* don't bother with grabbing reference only to drop it in the
  caller if it hadn't been shared in the first place
* in that form unshare_files() is trivially implemented via
  unshare_fd(), so we eliminate the duplicate logics in fork.c
* reset_files_struct() is not just only called for current;
  it will break the system if somebody ever calls it for anything
  else (we can't modify ->files of somebody else).  Lose the
  task_struct * argument.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/file.h b/include/linux/file.h
index 653477021e4..69baf5a4f0a 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -117,7 +117,8 @@ struct task_struct;
 
 struct files_struct *get_files_struct(struct task_struct *);
 void put_files_struct(struct files_struct *fs);
-void reset_files_struct(struct task_struct *, struct files_struct *);
+void reset_files_struct(struct files_struct *);
+int unshare_files(struct files_struct **);
 
 extern struct kmem_cache *files_cachep;