Amir Goldstein e506ac1dab ovl: hash directory inodes for fsnotify ... commit 31747eda41 upstream. fsnotify pins a watched directory inode in cache, but if directory dentry is released, new lookup will allocate a new dentry and a new inode. Directory events will be notified on the new inode, while fsnotify listener is watching the old pinned inode. Hash all directory inodes to reuse the pinned inode on lookup. Pure upper dirs are hashes by real upper inode, merge and lower dirs are hashed by real lower inode. The reference to lower inode was being held by the lower dentry object in the overlay dentry (oe->lowerstack[0]). Releasing the overlay dentry may drop lower inode refcount to zero. Add a refcount on behalf of the overlay inode to prevent that. As a by-product, hashing directory inodes also detects multiple redirected dirs to the same lower dir and uncovered redirected dir target on and returns -ESTALE on lookup. The reported issue dates back to initial version of overlayfs, but this patch depends on ovl_inode code that was introduced in kernel v4.13. Cc: <stable@vger.kernel.org> #v4.13 Reported-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-02-22 15:42:33 +01:00
..
Kconfig	ovl: introduce the inodes index dir feature	2017-07-04 22:03:17 +02:00
Makefile	ovl: split super.c	2016-12-16 11:02:56 +01:00
copy_up.c	ovl: fix missing unlock_rename() in ovl_do_copy_up()	2017-10-05 15:53:18 +02:00
dir.c	ovl: fix missing unlock_rename() in ovl_do_copy_up()	2017-10-05 15:53:18 +02:00
inode.c	ovl: hash directory inodes for fsnotify	2018-02-22 15:42:33 +01:00
namei.c	ovl: Pass ovl_get_nlink() parameters in right order	2017-12-20 10:10:18 +01:00
overlayfs.h	ovl: fix EIO from lookup of non-indexed upper	2017-10-24 16:06:16 +02:00
ovl_entry.h	locking/barriers: Convert users of lockless_dereference() to READ_ONCE()	2017-12-25 14:26:21 +01:00
readdir.c	ovl: take mnt_want_write() for removing impure xattr	2018-02-16 20:23:10 +01:00
super.c	ovl: hash directory inodes for fsnotify	2018-02-22 15:42:33 +01:00
util.c	ovl: hash directory inodes for fsnotify	2018-02-22 15:42:33 +01:00