Commit 60b86642 authored Jan 10, 2018 by Amir Goldstein Committed by Miklos Szeredi Jan 24, 2018

ovl: update documentation of inodes index feature



Document that inode index feature solves breaking hard links on
copy up.

Simplify Kconfig backward compatibility disclaimer.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent 05122443

Documentation/filesystems/overlayfs.txt

+3 −3

Original line number	Diff line number	Diff line
		@@ -281,9 +281,9 @@ filesystem, so both st_dev and st_ino of the file may change.

		Any open files referring to this inode will access the old data.

		If a file with multiple hard links is copied up, then this will
		"break" the link. Changes will not be propagated to other names
		referring to the same inode.
		Unless "inode index" feature is enabled, if a file with multiple hard
		links is copied up, then this will "break" the link. Changes will not be
		propagated to other names referring to the same inode.

		Unless "redirect_dir" feature is enabled, rename(2) on a lower or merged
		directory will fail with EXDEV.

fs/overlayfs/Kconfig

+3 −6

Original line number	Diff line number	Diff line
		@@ -47,9 +47,6 @@ config OVERLAY_FS_INDEX
		The inodes index feature prevents breaking of lower hardlinks on copy
		up.

		Note, that the inodes index feature is read-only backward compatible.
		That is, mounting an overlay which has an index dir on a kernel that
		doesn't support this feature read-only, will not have any negative
		outcomes. However, mounting the same overlay with an old kernel
		read-write and then mounting it again with a new kernel, will have
		unexpected results.
		Note, that the inodes index feature is not backward compatible.
		That is, mounting an overlay which has an inodes index on a kernel
		that doesn't support this feature will have unexpected results.