ovl: doc: add non-standard corner cases (5d3211b6) · Commits · 戴 / test

Documentation/filesystems/overlayfs.txt

+14 −2

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		@@ -336,8 +336,20 @@ the copied layers will fail the verification of the lower root file handle.
		Non-standard behavior
		---------------------

		Overlayfs can now act as a POSIX compliant filesystem with the following
		features turned on:
		Current version of overlayfs can act as a mostly POSIX compliant
		filesystem.

		This is the list of cases that overlayfs doesn't currently handle:

		a) POSIX mandates updating st_atime for reads. This is currently not
		done in the case when the file resides on a lower layer.

		b) If a file residing on a lower layer is opened for read-only and then
		memory mapped with MAP_SHARED, then subsequent changes to the file are not
		reflected in the memory mapping.

		The following options allow overlayfs to act more like a standards
		compliant filesystem:

		1) "redirect_dir"