[PATCH 0/7] overlayfs: fix ro/rw fd data inconsistecies

From: Miklos Szeredi
Date: Thu Nov 24 2016 - 05:55:52 EST


A file is opened for read-only, opened read-write (resulting in a copy up)
and modified. The data read back from the the read-only fd will be stale
in this case (the read-only file descriptor still refers to the lower,
unmodified file).

This patchset fixes issues related to this corner case.

The VFS impact is minimal and performance in the non-corner cases shouldn't
suffer.
---
Miklos Szeredi (7):
vfs: allow overlayfs to intercept file ops
vfs: export filp_clone_open()
mm: ovl: copy-up on MAP_SHARED
ovl: add infrastructure for intercepting file ops
ovl: intercept read_iter
ovl: intercept mmap
ovl: intercept fsync

fs/internal.h | 1 -
fs/open.c | 2 +-
fs/overlayfs/inode.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++
fs/overlayfs/overlayfs.h | 2 +
fs/overlayfs/super.c | 1 +
include/linux/fs.h | 1 +
mm/util.c | 22 +++++
7 files changed, 252 insertions(+), 2 deletions(-)

--
2.5.5