Lines Matching full:lower
26 non-directory objects may report an st_dev from the lower filesystem or
85 Upper and Lower
89 and a 'lower' filesystem. When a name exists in both filesystems, the
91 'lower' filesystem is either hidden or, in the case of directories,
94 It would be more correct to refer to an upper and lower 'directory
98 lower.
100 The lower filesystem can be any filesystem supported by Linux and does
101 not need to be writable. The lower filesystem can even be another
113 upper and lower filesystems and refers to a non-directory in either,
114 then the lower object is hidden - the name refers only to the upper
117 Where both upper and lower objects are directories, a merged directory
123 mount -t overlay overlay -olowerdir=/lower,upperdir=/upper,\
134 exists, else the lower.
138 directory only. These attributes of the lower directory are hidden.
143 In order to support rm and rmdir without changing the lower
150 matching name in the lower level is ignored, and the whiteout itself
155 directory in the lower filesystem with the same name is ignored.
161 lower directories are each read and the name lists merged in the
162 obvious way (upper is read first, then lower - entries that already
187 underlying directory (upper or lower).
192 When renaming a directory that is on the lower layer or merged (i.e. the
242 indexed by the file handle of the lower inode and a file handle of the
247 lower directory. In that case, lookup returns an error and warns about
250 Because lower layer redirects cannot be verified with the index, enabling
259 files etc.) are presented either from the upper or lower filesystem as
260 appropriate. When a file in the lower filesystem is accessed in a way
262 some metadata etc., the file is first copied from the lower filesystem
274 data is copied from the lower to the upper filesystem. Finally any
294 compared to direct access on underlying lower or upper filesystems
301 b) check if mounting task would be allowed real operation on lower or
317 mount -t overlay overlay -olowerdir=/lower,upperdir=/upper,... /merged
321 cp -a /lower /upper
328 Multiple lower layers
331 Multiple lower layers can now be given using the colon (":") as a
339 The specified lower directories will be stacked beginning from the
361 Do not use metacopy=on with untrusted upper/lower directories. Otherwise
363 appropriate REDIRECT and METACOPY xattrs, and gain access to file on lower
377 Lower layers may be shared among several overlay mounts and that is indeed
378 a very common practice. An overlay mount may use the same lower layer
379 path as another overlay mount and it may use a lower layer path that is
380 beneath or above the path of another overlay lower layer path.
391 different lower layer path, is allowed, unless the "inodes index" feature
395 handle of the lower layer root directory, along with the UUID of the lower
398 the lower root directory file handle and lower filesystem UUID are compared
400 lower root origin, mount will fail with ESTALE. An overlayfs mount with
401 "inodes index" enabled will fail with EOPNOTSUPP if the lower filesystem
402 does not support NFS export, lower filesystem does not have a valid UUID or
406 mount time. So if same upper is mounted with different set of lower, mount
412 the copied layers will fail the verification of the lower root file handle.
424 done in the case when the file resides on a lower layer.
426 b) If a file residing on a lower layer is opened for read-only and then
438 If this feature is disabled, then rename(2) on a lower or merged directory
471 the upper or the lower trees.
479 behavior on offline changes of the underlying lower layer is different
482 On every copy_up, an NFS file handle of the lower inode, along with the
483 UUID of the lower filesystem, are encoded and stored in an extended
487 that found a lower directory at the lookup path or at the path pointed
489 that the found lower directory file handle and lower filesystem UUID
491 found lower directory does not match the stored origin, that directory
502 With the "nfs_export" feature, on copy_up of any lower object, an index
513 1. For a non-upper object, encode a lower file handle from lower inode
514 2. For an indexed object, encode a lower file handle from copy_up origin
519 - Header including path type information (e.g. lower/upper)
530 3. For a lower file handle, lookup the handle in index directory by name.
542 When overlay filesystem has multiple lower layers, a middle layer
543 directory may have a "redirect" to lower directory. Because middle layer
544 "redirects" are not indexed, a lower file handle that was encoded from the
546 layer directory. Similarly, a lower file handle that was encoded from a
549 directories that cannot be decoded from a lower file handle, these