linux/fs/overlayfs
Amir Goldstein f168f1098d ovl: add support for "nfs_export" configuration
Introduce the "nfs_export" config, module and mount options.

The NFS export feature depends on the "index" feature and enables two
implicit overlayfs features: "index_all" and "verify_lower".
The "index_all" feature creates an index on copy up of every file and
directory. The "verify_lower" feature uses the full index to detect
overlay filesystems inconsistencies on lookup, like redirect from
multiple upper dirs to the same lower dir.

NFS export can be enabled for non-upper mount with no index. However,
because lower layer redirects cannot be verified with the index, enabling
NFS export support on an overlay with no upper layer requires turning off
redirect follow (e.g. "redirect_dir=nofollow").

The full index may incur some overhead on mount time, especially when
verifying that lower directory file handles are not stale.

NFS export support, full index and consistency verification will be
implemented by following patches.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-01-24 11:25:37 +01:00
..
copy_up.c ovl: generalize ovl_verify_origin() and helpers 2018-01-24 10:19:54 +01:00
dir.c ovl: take lower dir inode mutex outside upper sb_writers lock 2018-01-19 17:43:23 +01:00
inode.c ovl: hash directory inodes for fsnotify 2018-01-19 13:54:33 +01:00
Kconfig ovl: add support for "nfs_export" configuration 2018-01-24 11:25:37 +01:00
Makefile ovl: split super.c 2016-12-16 11:02:56 +01:00
namei.c ovl: generalize ovl_verify_origin() and helpers 2018-01-24 10:19:54 +01:00
overlayfs.h ovl: add support for "nfs_export" configuration 2018-01-24 11:25:37 +01:00
ovl_entry.h ovl: add support for "nfs_export" configuration 2018-01-24 11:25:37 +01:00
readdir.c ovl: simplify arguments to ovl_check_origin_fh() 2018-01-24 10:19:46 +01:00
super.c ovl: add support for "nfs_export" configuration 2018-01-24 11:25:37 +01:00
util.c ovl: add support for "nfs_export" configuration 2018-01-24 11:25:37 +01:00