cc0918b358
[ Upstream commit 24e16e385f2272b1a9df51337a5c32d28a29c7ad ] Add new mount options lowerdir+ and datadir+ that can be used to add layers to lower layers stack one by one. Unlike the legacy lowerdir mount option, special characters (i.e. colons and cammas) are not unescaped with these new mount options. The new mount options can be repeated to compose a large stack of lower layers, but they may not be mixed with the lagacy lowerdir mount option, because for displaying lower layers in mountinfo, we do not want to mix escaped with unescaped lower layers path syntax. Similar to data-only layer rules with the lowerdir mount option, the datadir+ option must follow at least one lowerdir+ option and the lowerdir+ option must not follow the datadir+ option. If the legacy lowerdir mount option follows lowerdir+ and datadir+ mount options, it overrides them. Sepcifically, calling: fsconfig(FSCONFIG_SET_STRING, "lowerdir", "", 0); can be used to reset previously setup lower layers. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Link: https://lore.kernel.org/r/CAJfpegt7VC94KkRtb1dfHG8+4OzwPBLYqhtc8=QFUxpFJE+=RQ@mail.gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Stable-dep-of: 2824083db76c ("ovl: Always reject mounting over case-insensitive directories") Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.