1config OVERLAY_FS 2 tristate "Overlay filesystem support" 3 select EXPORTFS 4 help 5 An overlay filesystem combines two filesystems - an 'upper' filesystem 6 and a 'lower' filesystem. When a name exists in both filesystems, the 7 object in the 'upper' filesystem is visible while the object in the 8 'lower' filesystem is either hidden or, in the case of directories, 9 merged with the 'upper' object. 10 11 For more information see Documentation/filesystems/overlayfs.txt 12 13config OVERLAY_FS_REDIRECT_DIR 14 bool "Overlayfs: turn on redirect dir feature by default" 15 depends on OVERLAY_FS 16 help 17 If this config option is enabled then overlay filesystems will use 18 redirects when renaming directories by default. In this case it is 19 still possible to turn off redirects globally with the 20 "redirect_dir=off" module option or on a filesystem instance basis 21 with the "redirect_dir=off" mount option. 22 23 Note, that redirects are not backward compatible. That is, mounting 24 an overlay which has redirects on a kernel that doesn't support this 25 feature will have unexpected results. 26