Documentation/block: drop the request.rst file

Documentation/block/request.rst is outdated and should be removed.
Also delete its entry in the block/index.rst file.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20230507182606.12647-1-rdunlap@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: stub out and deprecated the capability attribute on the gendisk

The capability attribute was added in 2017 to expose the kernel internal
GENHD_FL_MEDIA_CHANGE_NOTIFY to userspace without ever adding a value to
an UAPI header, and without ever setting it in any driver until it was
finally removed in Linux 5.7.

Deprecate the file and always return 0 instead of exposing the other
internal and frequently renumbered other gendisk flags.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230203150209.3199115-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Documentation: document ublk

Add documentation for ublk subsystem. It was supposed to be documented when
merging the driver, but missing at that time.

Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Richard W.M. Jones <rjones@redhat.com>
Cc: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
[axboe: correct MAINTAINERS addition]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove biodoc.rst

This document is completely out of date and extremely misleading. In
general the existing kerneldoc comment serve as a much better
documentation of the still existing functionality, while the history
blurbs are pretty much irrelevant today.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220215081047.3693582-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

docs: block: remove queue-sysfs.rst

This has been replaced by Documentation/ABI/stable/sysfs-block, which is
the correct place for sysfs documentation.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20211209003833.6396-8-ebiggers@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

docs: block: Create blk-mq documentation

Create a documentation providing a background and explanation around the
operation of the Multi-Queue Block IO Queueing Mechanism (blk-mq).

The reference for writing this documentation was the source code and
"Linux Block IO: Introducing Multi-queue SSD Access on Multi-core
Systems", by Axboe et al.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200620002036.113000-1-andrealmeid@collabora.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation: Document the blk-crypto framework

The blk-crypto framework adds support for inline encryption. There are
numerous changes throughout the storage stack. This patch documents the
main design choices in the block layer, the API presented to users of
the block layer (like fscrypt or layered devices) and the API presented
to drivers for adding support for inline encryption.

Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

docs: add some documentation dirs to the driver-api book

Those are subsystem docs, with a mix of kABI and user-faced
docs. While they're not split, keep the dirs where they are,
adding just a pointer to the main index.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

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>