docs: convert docs to ReST and rename to *.rst

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 108 deletions

diff --git a/Documentation/device-mapper/era.txt b/Documentation/device-mapper/era.txt
deleted file mode 100644
index 3c6d01be3560..000000000000
--- a/Documentation/device-mapper/era.txt
+++ /dev/null
@@ -1,108 +0,0 @@
-Introduction
-============
-
-dm-era is a target that behaves similar to the linear target.  In
-addition it keeps track of which blocks were written within a user
-defined period of time called an 'era'.  Each era target instance
-maintains the current era as a monotonically increasing 32-bit
-counter.
-
-Use cases include tracking changed blocks for backup software, and
-partially invalidating the contents of a cache to restore cache
-coherency after rolling back a vendor snapshot.
-
-Constructor
-===========
-
- era <metadata dev> <origin dev> <block size>
-
- metadata dev    : fast device holding the persistent metadata
- origin dev	 : device holding data blocks that may change
- block size      : block size of origin data device, granularity that is
-		     tracked by the target
-
-Messages
-========
-
-None of the dm messages take any arguments.
-
-checkpoint
-----------
-
-Possibly move to a new era.  You shouldn't assume the era has
-incremented.  After sending this message, you should check the
-current era via the status line.
-
-take_metadata_snap
-------------------
-
-Create a clone of the metadata, to allow a userland process to read it.
-
-drop_metadata_snap
-------------------
-
-Drop the metadata snapshot.
-
-Status
-======
-
-<metadata block size> <#used metadata blocks>/<#total metadata blocks>
-<current era> <held metadata root | '-'>
-
-metadata block size	 : Fixed block size for each metadata block in
-			     sectors
-#used metadata blocks	 : Number of metadata blocks used
-#total metadata blocks	 : Total number of metadata blocks
-current era		 : The current era
-held metadata root	 : The location, in blocks, of the metadata root
-			     that has been 'held' for userspace read
-			     access. '-' indicates there is no held root
-
-Detailed use case
-=================
-
-The scenario of invalidating a cache when rolling back a vendor
-snapshot was the primary use case when developing this target:
-
-Taking a vendor snapshot
-------------------------
-
-- Send a checkpoint message to the era target
-- Make a note of the current era in its status line
-- Take vendor snapshot (the era and snapshot should be forever
-  associated now).
-
-Rolling back to an vendor snapshot
-----------------------------------
-
-- Cache enters passthrough mode (see: dm-cache's docs in cache.txt)
-- Rollback vendor storage
-- Take metadata snapshot
-- Ascertain which blocks have been written since the snapshot was taken
-  by checking each block's era
-- Invalidate those blocks in the caching software
-- Cache returns to writeback/writethrough mode
-
-Memory usage
-============
-
-The target uses a bitset to record writes in the current era.  It also
-has a spare bitset ready for switching over to a new era.  Other than
-that it uses a few 4k blocks for updating metadata.
-
-   (4 * nr_blocks) bytes + buffers
-
-Resilience
-==========
-
-Metadata is updated on disk before a write to a previously unwritten
-block is performed.  As such dm-era should not be effected by a hard
-crash such as power failure.
-
-Userland tools
-==============
-
-Userland tools are found in the increasingly poorly named
-thin-provisioning-tools project:
-
-    https://github.com/jthornber/thin-provisioning-tools