docs: filesystems: convert efivarfs.txt to ReST

Trivial changes:

- Add a SPDX header;
- Adjust document title;
- Mark a literal block as such;
- Add it to filesystems/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/215691d747055c4ccb038ec7d78d8d1fe87fe2c0.1581955849.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/filesystems/efivarfs.rst b/Documentation/filesystems/efivarfs.rst
new file mode 100644 (file)
index 0000000..90ac656
--- /dev/null
+++ b/Documentation/filesystems/efivarfs.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+efivarfs - a (U)EFI variable filesystem
+=======================================
+
+The efivarfs filesystem was created to address the shortcomings of
+using entries in sysfs to maintain EFI variables. The old sysfs EFI
+variables code only supported variables of up to 1024 bytes. This
+limitation existed in version 0.99 of the EFI specification, but was
+removed before any full releases. Since variables can now be larger
+than a single page, sysfs isn't the best interface for this.
+
+Variables can be created, deleted and modified with the efivarfs
+filesystem.
+
+efivarfs is typically mounted like this::
+
+       mount -t efivarfs none /sys/firmware/efi/efivars
+
+Due to the presence of numerous firmware bugs where removing non-standard
+UEFI variables causes the system firmware to fail to POST, efivarfs
+files that are not well-known standardized variables are created
+as immutable files.  This doesn't prevent removal - "chattr -i" will work -
+but it does prevent this kind of failure from being accomplished
+accidentally.

diff --git a/Documentation/filesystems/efivarfs.txt b/Documentation/filesystems/efivarfs.txt
deleted file mode 100644 (file)
index 686a64b..0000000
--- a/Documentation/filesystems/efivarfs.txt
+++ /dev/null
@@ -1,23 +0,0 @@
-
-efivarfs - a (U)EFI variable filesystem
-
-The efivarfs filesystem was created to address the shortcomings of
-using entries in sysfs to maintain EFI variables. The old sysfs EFI
-variables code only supported variables of up to 1024 bytes. This
-limitation existed in version 0.99 of the EFI specification, but was
-removed before any full releases. Since variables can now be larger
-than a single page, sysfs isn't the best interface for this.
-
-Variables can be created, deleted and modified with the efivarfs
-filesystem.
-
-efivarfs is typically mounted like this,
-
-       mount -t efivarfs none /sys/firmware/efi/efivars
-
-Due to the presence of numerous firmware bugs where removing non-standard
-UEFI variables causes the system firmware to fail to POST, efivarfs
-files that are not well-known standardized variables are created
-as immutable files.  This doesn't prevent removal - "chattr -i" will work -
-but it does prevent this kind of failure from being accomplished
-accidentally.

diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index d6d69f1..4230f49 100644 (file)
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -60,6 +60,7 @@ Documentation for filesystem implementations.
    debugfs
    dlmfs
    ecryptfs
+   efivarfs
    fuse
    overlayfs
    virtiofs