Documentation/filesystems/overlayfs.rst

90 merged with the 'upper' object.
117 Where both upper and lower objects are directories, a merged directory
121 "upperdir" are combined into a merged directory::
124   workdir=/work /merged
129 Then whenever a lookup is requested in such a merged directory, the
132 actual lookups find directories, both are stored and a merged
136 Only the lists of names from directories are merged.  Other content
151 When a whiteout is found in the upper level of a merged directory, any
169 When a 'readdir' request is made on a merged directory, the upper and
170 lower directories are each read and the name lists merged in the
172 exist are not re-added).  This merged name list is cached in the
179 This means that changes to the merged directory do not appear while a
195 Readdir on directories that are not merged is simply handled by the
201 When renaming a directory that is on the lower layer or merged (i.e. the
252 on the index entry.  On lookup of a merged directory, if the upper
325   mount -t overlay overlay -olowerdir=/lower,upperdir=/upper,... /merged
330   mount --bind /upper /merged
342   mount -t overlay overlay -olowerdir=/lower1:/lower2:/lower3 /merged
354   mount -t overlay overlay -olowerdir=/a\:lower\:\:dir /merged
422   mount -t overlay overlay -olowerdir=/l1:/l2:/l3::/do1::/do2 /merged
425 merged overlayfs directories and the metadata and st_ino/st_dev of files
582 If this feature is disabled, then rename(2) on a lower or merged directory
636 When the NFS export feature is enabled, a lookup of a merged directory,
642 will not be merged with the upper directory.