From 4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 18 Jun 2015 14:32:31 +0100 Subject: overlayfs: Make f_path always point to the overlay and f_inode to the underlay Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5 /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5 /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/internal.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/internal.h') diff --git a/fs/internal.h b/fs/internal.h index 01dce1d..4d5af58 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -107,6 +107,7 @@ extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, extern long do_handle_open(int mountdirfd, struct file_handle __user *ufh, int open_flag); extern int open_check_o_direct(struct file *f); +extern int vfs_open(const struct path *, struct file *, const struct cred *); /* * inode.c -- cgit v1.1