linux-stable/fs/overlayfs
Amir Goldstein 37ebf056d6 ovl: introduce data-only lower layers
Introduce the format lowerdir=lower1:lower2::lowerdata1::lowerdata2
where the lower layers on the right of the :: separators are not merged
into the overlayfs merge dirs.

Data-only lower layers are only allowed at the bottom of the stack.

The files in those layers are only meant to be accessible via absolute
redirect from metacopy files in lower layers.  Following changes will
implement lookup in the data layers.

This feature was requested for composefs ostree use case, where the
lower data layer should only be accessiable via absolute redirects
from metacopy inodes.

The lower data layers are not required to a have a unique uuid or any
uuid at all, because they are never used to compose the overlayfs inode
st_ino/st_dev.

Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-06-19 14:01:13 +03:00
..
copy_up.c ovl: update of dentry revalidate flags after copy up 2023-06-19 14:01:12 +03:00
dir.c ovl: move ovl_entry into ovl_inode 2023-06-19 14:01:13 +03:00
export.c ovl: deduplicate lowerpath and lowerstack[] 2023-06-19 14:01:13 +03:00
file.c fs: port inode_owner_or_capable() to mnt_idmap 2023-01-19 09:24:29 +01:00
inode.c ovl: deduplicate lowerdata and lowerstack[] 2023-06-19 14:01:13 +03:00
Kconfig ovl: Kconfig: Fix spelling mistake "undelying" -> "underlying" 2022-12-08 10:49:46 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
namei.c ovl: introduce data-only lower layers 2023-06-19 14:01:13 +03:00
overlayfs.h ovl: deduplicate lowerdata and lowerstack[] 2023-06-19 14:01:13 +03:00
ovl_entry.h ovl: introduce data-only lower layers 2023-06-19 14:01:13 +03:00
readdir.c fs: port ->permission() to pass mnt_idmap 2023-01-19 09:24:28 +01:00
super.c ovl: introduce data-only lower layers 2023-06-19 14:01:13 +03:00
util.c ovl: deduplicate lowerdata and lowerstack[] 2023-06-19 14:01:13 +03:00