f96384a621
commit 9c6d8f13e9da10a26ad7f0a020ef86e8ef142835 upstream.
On non-samefs overlay without xino, non pure upper inodes should use a
pseudo_dev assigned to each unique lower fs and pure upper inodes use the
real upper st_dev.
It is fine for an overlay pure upper inode to use the same st_dev;st_ino
values as the real upper inode, because the content of those two different
filesystem objects is always the same.
In this case, however:
- two filesystems, A and B
- upper layer is on A
- lower layer 1 is also on A
- lower layer 2 is on B
Non pure upper overlay inode, whose origin is in layer 1 will have the same
st_dev;st_ino values as the real lower inode. This may result with a false
positive results of 'diff' between the real lower and copied up overlay
inode.
Fix this by using the upper st_dev;st_ino values in this case. This breaks
the property of constant st_dev;st_ino across copy up of this case. This
breakage will be fixed by a later patch.
Fixes: 5148626b806a ("ovl: allocate anon bdev per unique lower fs")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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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
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the problems which may result by upgrading your kernel.