block: remove pktcdvd driver

This driver has long outlived it's utility, and it's broken and unloved.
The main use case for this was direct mount with UDF of cd-rw drives
that required 32kb packets. It would collect writes into that size and
write them out in multiples of that. That's not a common use case
anymore, the world has moved on from those kinds of media. To make
matters worse, it's actively breaking setups where it's not even
required or useful.

Link: https://lore.kernel.org/linux-block/fxg6dksau4jsk3u5xldlyo2m7qgiux6vtdrz5rywseotsouqdv@urcrwz6qtd3r/
Link: https://lore.kernel.org/linux-block/dcc4836e-6da9-4208-ad27-bbd44b3a2063@kernel.dk/
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 0 insertions, 255 deletions

diff --git a/Documentation/ABI/testing/debugfs-pktcdvd b/Documentation/ABI/testing/debugfs-pktcdvd
deleted file mode 100644
index f6f65a4faea0..000000000000
--- a/Documentation/ABI/testing/debugfs-pktcdvd
+++ /dev/null
@@ -1,18 +0,0 @@
-What:           /sys/kernel/debug/pktcdvd/pktcdvd[0-7]
-Date:           Oct. 2006
-KernelVersion:  2.6.20
-Contact:        Thomas Maier <balagi@justmail.de>
-Description:
-
-The pktcdvd module (packet writing driver) creates
-these files in debugfs:
-
-/sys/kernel/debug/pktcdvd/pktcdvd[0-7]/
-
-    ====            ====== ====================================
-    info            0444   Lots of driver statistics and infos.
-    ====            ====== ====================================
-
-Example::
-
-    cat /sys/kernel/debug/pktcdvd/pktcdvd0/info
diff --git a/Documentation/ABI/testing/sysfs-class-pktcdvd b/Documentation/ABI/testing/sysfs-class-pktcdvd
deleted file mode 100644
index ba1ce626591d..000000000000
--- a/Documentation/ABI/testing/sysfs-class-pktcdvd
+++ /dev/null
@@ -1,97 +0,0 @@
-sysfs interface
----------------
-The pktcdvd module (packet writing driver) creates the following files in the
-sysfs: (<devid> is in the format major:minor)
-
-What:		/sys/class/pktcdvd/add
-What:		/sys/class/pktcdvd/remove
-What:		/sys/class/pktcdvd/device_map
-Date:		Oct. 2006
-KernelVersion:	2.6.20
-Contact:	Thomas Maier <balagi@justmail.de>
-Description:
-
-		==========	==============================================
-		add		(WO) Write a block device id (major:minor) to
-				create a new pktcdvd device and map it to the
-				block device.
-
-		remove		(WO) Write the pktcdvd device id (major:minor)
-				to remove the pktcdvd device.
-
-		device_map	(RO) Shows the device mapping in format:
-				pktcdvd[0-7] <pktdevid> <blkdevid>
-		==========	==============================================
-
-
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/dev
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/uevent
-Date:		Oct. 2006
-KernelVersion:	2.6.20
-Contact:	Thomas Maier <balagi@justmail.de>
-Description:
-		dev:	(RO) Device id
-
-		uevent:	(WO) To send a uevent
-
-
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_started
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_finished
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_written
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read_gather
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/stat/reset
-Date:		Oct. 2006
-KernelVersion:	2.6.20
-Contact:	Thomas Maier <balagi@justmail.de>
-Description:
-		packets_started:	(RO) Number of started packets.
-
-		packets_finished:	(RO) Number of finished packets.
-
-		kb_written:		(RO) kBytes written.
-
-		kb_read:		(RO) kBytes read.
-
-		kb_read_gather:		(RO) kBytes read to fill write packets.
-
-		reset:			(WO) Write any value to it to reset
-					pktcdvd device statistic values, like
-					bytes read/written.
-
-
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/size
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_off
-What:		/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_on
-Date:		Oct. 2006
-KernelVersion:	2.6.20
-Contact:	Thomas Maier <balagi@justmail.de>
-Description:
-		==============	================================================
-		size		(RO) Contains the size of the bio write queue.
-
-		congestion_off	(RW) If bio write queue size is below this mark,
-				accept new bio requests from the block layer.
-
-		congestion_on	(RW) If bio write queue size is higher as this
-				mark, do no longer accept bio write requests
-				from the block layer and wait till the pktcdvd
-				device has processed enough bio's so that bio
-				write queue size is below congestion off mark.
-				A value of <= 0 disables congestion control.
-		==============	================================================
-
-
-Example:
---------
-To use the pktcdvd sysfs interface directly, you can do::
-
-    # create a new pktcdvd device mapped to /dev/hdc
-    echo "22:0" >/sys/class/pktcdvd/add
-    cat /sys/class/pktcdvd/device_map
-    # assuming device pktcdvd0 was created, look at stat's
-    cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written
-    # print the device id of the mapped block device
-    fgrep pktcdvd0 /sys/class/pktcdvd/device_map
-    # remove device, using pktcdvd0 device id   253:0
-    echo "253:0" >/sys/class/pktcdvd/remove
diff --git a/Documentation/cdrom/packet-writing.rst b/Documentation/cdrom/packet-writing.rst
deleted file mode 100644
index 43db58c50d29..000000000000
--- a/Documentation/cdrom/packet-writing.rst
+++ /dev/null
@@ -1,139 +0,0 @@
-==============
-Packet writing
-==============
-
-Getting started quick
----------------------
-
-- Select packet support in the block device section and UDF support in
-  the file system section.
-
-- Compile and install kernel and modules, reboot.
-
-- You need the udftools package (pktsetup, mkudffs, cdrwtool).
-  Download from https://github.com/pali/udftools
-
-- Grab a new CD-RW disc and format it (assuming CD-RW is hdc, substitute
-  as appropriate)::
-
-	# cdrwtool -d /dev/hdc -q
-
-- Setup your writer::
-
-	# pktsetup dev_name /dev/hdc
-
-- Now you can mount /dev/pktcdvd/dev_name and copy files to it. Enjoy::
-
-	# mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
-
-
-Packet writing for DVD-RW media
--------------------------------
-
-DVD-RW discs can be written to much like CD-RW discs if they are in
-the so called "restricted overwrite" mode. To put a disc in restricted
-overwrite mode, run::
-
-	# dvd+rw-format /dev/hdc
-
-You can then use the disc the same way you would use a CD-RW disc::
-
-	# pktsetup dev_name /dev/hdc
-	# mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
-
-
-Packet writing for DVD+RW media
--------------------------------
-
-According to the DVD+RW specification, a drive supporting DVD+RW discs
-shall implement "true random writes with 2KB granularity", which means
-that it should be possible to put any filesystem with a block size >=
-2KB on such a disc. For example, it should be possible to do::
-
-	# dvd+rw-format /dev/hdc   (only needed if the disc has never
-	                            been formatted)
-	# mkudffs /dev/hdc
-	# mount /dev/hdc /cdrom -t udf -o rw,noatime
-
-However, some drives don't follow the specification and expect the
-host to perform aligned writes at 32KB boundaries. Other drives do
-follow the specification, but suffer bad performance problems if the
-writes are not 32KB aligned.
-
-Both problems can be solved by using the pktcdvd driver, which always
-generates aligned writes::
-
-	# dvd+rw-format /dev/hdc
-	# pktsetup dev_name /dev/hdc
-	# mkudffs /dev/pktcdvd/dev_name
-	# mount /dev/pktcdvd/dev_name /cdrom -t udf -o rw,noatime
-
-
-Packet writing for DVD-RAM media
---------------------------------
-
-DVD-RAM discs are random writable, so using the pktcdvd driver is not
-necessary. However, using the pktcdvd driver can improve performance
-in the same way it does for DVD+RW media.
-
-
-Notes
------
-
-- CD-RW media can usually not be overwritten more than about 1000
-  times, so to avoid unnecessary wear on the media, you should always
-  use the noatime mount option.
-
-- Defect management (ie automatic remapping of bad sectors) has not
-  been implemented yet, so you are likely to get at least some
-  filesystem corruption if the disc wears out.
-
-- Since the pktcdvd driver makes the disc appear as a regular block
-  device with a 2KB block size, you can put any filesystem you like on
-  the disc. For example, run::
-
-	# /sbin/mke2fs /dev/pktcdvd/dev_name
-
-  to create an ext2 filesystem on the disc.
-
-
-Using the pktcdvd sysfs interface
----------------------------------
-
-Since Linux 2.6.20, the pktcdvd module has a sysfs interface
-and can be controlled by it. For example the "pktcdvd" tool uses
-this interface. (see http://tom.ist-im-web.de/linux/software/pktcdvd )
-
-"pktcdvd" works similar to "pktsetup", e.g.::
-
-	# pktcdvd -a dev_name /dev/hdc
-	# mkudffs /dev/pktcdvd/dev_name
-	# mount -t udf -o rw,noatime /dev/pktcdvd/dev_name /dvdram
-	# cp files /dvdram
-	# umount /dvdram
-	# pktcdvd -r dev_name
-
-
-For a description of the sysfs interface look into the file:
-
-  Documentation/ABI/testing/sysfs-class-pktcdvd
-
-
-Using the pktcdvd debugfs interface
------------------------------------
-
-To read pktcdvd device infos in human readable form, do::
-
-	# cat /sys/kernel/debug/pktcdvd/pktcdvd[0-7]/info
-
-For a description of the debugfs interface look into the file:
-
-  Documentation/ABI/testing/debugfs-pktcdvd
-
-
-
-Links
------
-
-See http://fy.chalmers.se/~appro/linux/DVD+RW/ for more information
-about DVD writing.
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index bc91756bde73..4f1532a251d2 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -220,7 +220,6 @@ Code  Seq#    Include File                                           Comments
              include/linux/falloc.h,
              linux/fs.h,
 'X'   all    fs/ocfs2/ocfs_fs.h                                      conflict!
-'X'   01     linux/pktcdvd.h                                         conflict!
 'Z'   14-15  drivers/message/fusion/mptctl.h
 '['   00-3F  linux/usb/tmc.h                                         USB Test and Measurement Devices
                                                                      <mailto:gregkh@linuxfoundation.org>