signal/timer/event fds: anonymous inode source

This patch add an anonymous inode source, to be used for files that need
and inode only in order to create a file*. We do not care of having an
inode for each file, and we do not even care of having different names in
the associated dentries (dentry names will be same for classes of file*).
This allow code reuse, and will be used by epoll, signalfd and timerfd
(and whatever else there'll be).

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 322b1f8c21b3..a80bd8326bc6 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -475,9 +475,19 @@ config FUTEX
           support for "fast userspace mutexes".  The resulting kernel may not
           run glibc-based applications correctly.
 
+config ANON_INODES
+        bool "Enable anonymous inode source" if EMBEDDED
+        default y
+        help
+          Anonymous inode source for pseudo-files like epoll, signalfd,
+          timerfd and eventfd.
+
+          If unsure, say Y.
+
 config EPOLL
         bool "Enable eventpoll support" if EMBEDDED
         default y
+        depends on ANON_INODES
         help
           Disabling this option will cause the kernel to be built without
           support for epoll family of system calls.