From 60b866420ba7ae0b6a8d338f49be21c601d19064 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 10 Jan 2018 23:15:21 +0200 Subject: 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 Signed-off-by: Miklos Szeredi --- Documentation/filesystems/overlayfs.txt | 6 +++--- fs/overlayfs/Kconfig | 9 +++------ 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt index e6a5f4912b6d..213547cb6d36 100644 --- a/Documentation/filesystems/overlayfs.txt +++ b/Documentation/filesystems/overlayfs.txt @@ -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. diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig index 5ac415466861..9eac01c3e21e 100644 --- a/fs/overlayfs/Kconfig +++ b/fs/overlayfs/Kconfig @@ -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. -- cgit v1.2.3