docs: block: convert to ReST

Rename the block documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

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>

block/Kconfig

@@ -110,7 +110,7 @@ config BLK_CMDLINE_PARSER
 	which don't otherwise have any standardized method for listing the
 	partitions on a block device.
 
-	See Documentation/block/cmdline-partition.txt for more information.
+	See Documentation/block/cmdline-partition.rst for more information.
 
 config BLK_WBT
 	bool "Enable support for block device writeback throttling"

block/Kconfig.iosched

@@ -26,7 +26,7 @@ config IOSCHED_BFQ
 	regardless of the device parameters and with any workload. It
 	also guarantees a low latency to interactive and soft
 	real-time applications.  Details in
-	Documentation/block/bfq-iosched.txt
+	Documentation/block/bfq-iosched.rst
 
 config BFQ_GROUP_IOSCHED
        bool "BFQ hierarchical scheduling support"

block/bfq-iosched.c

@@ -17,7 +17,7 @@
  * low-latency capabilities. BFQ also supports full hierarchical
  * scheduling through cgroups. Next paragraphs provide an introduction
  * on BFQ inner workings. Details on BFQ benefits, usage and
- * limitations can be found in Documentation/block/bfq-iosched.txt.
+ * limitations can be found in Documentation/block/bfq-iosched.rst.
  *
  * BFQ is a proportional-share storage-I/O scheduling algorithm based
  * on the slice-by-slice service scheme of CFQ. But BFQ assigns

block/blk-integrity.c

@@ -383,7 +383,7 @@ static const struct blk_integrity_profile nop_profile = {
  * send/receive integrity metadata it must use this function to register
  * the capability with the block layer. The template is a blk_integrity
  * struct with values appropriate for the underlying hardware. See
- * Documentation/block/data-integrity.txt.
+ * Documentation/block/data-integrity.rst.
  */
 void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 {

block/ioprio.c

@@ -17,7 +17,7 @@
  *
  * ioprio_set(PRIO_PROCESS, pid, prio);
  *
- * See also Documentation/block/ioprio.txt
+ * See also Documentation/block/ioprio.rst
  *
  */
 #include <linux/gfp.h>

block/mq-deadline.c

@@ -25,7 +25,7 @@
 #include "blk-mq-sched.h"
 
 /*
- * See Documentation/block/deadline-iosched.txt
+ * See Documentation/block/deadline-iosched.rst
  */
 static const int read_expire = HZ / 2;  /* max time before a read is submitted. */
 static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */

block/partitions/cmdline.c

@@ -11,7 +11,7 @@
  *
  * The format for the command line is just like mtdparts.
  *
- * For further information, see "Documentation/block/cmdline-partition.txt"
+ * For further information, see "Documentation/block/cmdline-partition.rst"
  *
  */