linux-next/fs/overlayfs
Amir Goldstein 695b46e76b ovl: set i_ino to the value of st_ino for NFS export
Eddie Horng reported that readdir of an overlayfs directory that
was exported via NFSv3 returns entries with d_type set to DT_UNKNOWN.
The reason is that while preparing the response for readdirplus, nfsd
checks inside encode_entryplus_baggage() that a child dentry's inode
number matches the value of d_ino returns by overlayfs readdir iterator.

Because the overlayfs inodes use arbitrary inode numbers that are not
correlated with the values of st_ino/d_ino, NFSv3 falls back to not
encoding d_type. Although this is an allowed behavior, we can fix it for
the case of all overlayfs layers on the same underlying filesystem.

When NFS export is enabled and d_ino is consistent with st_ino
(samefs), set the same value also to i_ino in ovl_fill_inode() for all
overlayfs inodes, nfsd readdirplus sanity checks will pass.
ovl_fill_inode() may be called from ovl_new_inode(), before real inode
was created with ino arg 0. In that case, i_ino will be updated to real
upper inode i_ino on ovl_inode_init() or ovl_inode_update().

Reported-by: Eddie Horng <eddiehorng.tw@gmail.com>
Tested-by: Eddie Horng <eddiehorng.tw@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: 8383f17488 ("ovl: wire up NFS export operations")
Cc: <stable@vger.kernel.org> #v4.16
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-04-12 12:04:48 +02:00
..
copy_up.c ovl: copy up of disconnected dentries 2018-01-24 11:25:58 +01:00
dir.c ovl: whiteout index when union nlink drops to zero 2018-01-24 11:25:56 +01:00
export.c ovl: fix ptr_ret.cocci warnings 2018-02-26 12:45:20 +01:00
inode.c ovl: set i_ino to the value of st_ino for NFS export 2018-04-12 12:04:48 +02:00
Kconfig ovl: update Kconfig texts 2018-03-07 11:47:15 +01:00
Makefile ovl: encode pure upper file handles 2018-01-24 11:25:59 +01:00
namei.c ovl: redirect_dir=nofollow should not follow redirect for opaque lower 2018-02-26 16:55:51 +01:00
overlayfs.h ovl: check lower ancestry on encode of lower dir file handle 2018-02-16 15:53:20 +01:00
ovl_entry.h ovl: store 'has_upper' and 'opaque' as bit flags 2018-01-24 11:25:58 +01:00
readdir.c ovl: whiteout orphan index entries on mount 2018-01-24 11:25:56 +01:00
super.c ovl: check lower ancestry on encode of lower dir file handle 2018-02-16 15:53:20 +01:00
util.c ovl: set i_ino to the value of st_ino for NFS export 2018-04-12 12:04:48 +02:00