docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eCryptfs: allow userspace messaging to be disabled

When the userspace messaging (for the less common case of userspace key
wrap/unwrap via ecryptfsd) is not needed, allow eCryptfs to build with
it removed. This saves on kernel code size and reduces potential attack
surface by removing the /dev/ecryptfs node.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

fs/ecryptfs: remove depends on CONFIG_EXPERIMENTAL

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Tyler Hicks <tyhicks@canonical.com>
CC: Dustin Kirkland <dustin.kirkland@gazzang.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Tyler Hicks <tyhicks@canonical.com>

eCryptfs: fix compile error

This patch fixes the compile error reported at the address:

https://bugzilla.kernel.org/show_bug.cgi?id=40292

The problem arises when compiling eCryptfs as built-in and the 'encrypted'
key type as a module. The patch prevents this combination from being set in
the kernel configuration, by fixing the eCryptfs dependencies.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Reported-by: David Hill <hilld@binarystorm.net>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

eCryptfs: Remove Kconfig NET dependency and select MD5

eCryptfs no longer uses a netlink interface to communicate with
ecryptfsd, so NET is not a valid dependency anymore.

MD5 is required and must be built for eCryptfs to be of any use.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

ecryptfs: depends on CRYPTO

ecryptfs uses crypto APIs so it should depend on CRYPTO.
Otherwise many build errors occur. [63 lines not pasted]

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: ecryptfs-devel@lists.launchpad.net
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

ecryptfs: improved dependency checking and reporting

So, I compiled a 2.6.31-rc5 kernel with ecryptfs and loaded its module.
When it came time to mount my filesystem, I got this in dmesg, and it
refused to mount:

[93577.776637] Unable to allocate crypto cipher with name [aes]; rc = [-2]
[93577.783280] Error attempting to initialize key TFM cipher with name = [aes]; rc = [-2]
[93577.791183] Error attempting to initialize cipher with name = [aes] and key size = [32]; rc = [-2]
[93577.800113] Error parsing options; rc = [-22]

I figured from the error message that I'd either forgotten to load "aes"
or that my key size was bogus. Neither one of those was the case. In
fact, I was missing the CRYPTO_ECB config option and the 'ecb' module.
Unfortunately, there's no trace of 'ecb' in that error message.

I've done two things to fix this. First, I've modified ecryptfs's
Kconfig entry to select CRYPTO_ECB and CRYPTO_CBC. I also took CRYPTO
out of the dependencies since the 'select' will take care of it for us.

I've also modified the error messages to print a string that should
contain both 'ecb' and 'aes' in my error case. That will give any
future users a chance of finding the right modules and Kconfig options.

I also wonder if we should:

select CRYPTO_AES if !EMBEDDED

since I think most ecryptfs users are using AES like me.

Cc: ecryptfs-devel@lists.launchpad.net
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
[tyhicks@linux.vnet.ibm.com: Removed extra newline, 80-char violation]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

fs/Kconfig: move ecryptfs out

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>