block-2023-01-06

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Merge tag 'block-2023-01-06' of git://git.kernel.dk/linux

Pull block fixes from Jens Axboe:
 "The big change here is obviously the revert of the pktcdvd driver
  removal. Outside of that, just minor tweaks. In detail:

   - Re-instate the pktcdvd driver, which necessitates adding back
     bio_copy_data_iter() and the fops->devnode() hook for now (me)

   - Fix for splitting of a bio marked as NOWAIT, causing either nowait
     reads or writes to error with EAGAIN even if parts of the IO
     completed (me)

   - Fix for ublk, punting management commands to io-wq as they can all
     easily block for extended periods of time (Ming)

   - Removal of SRCU dependency for the block layer (Paul)"

* tag 'block-2023-01-06' of git://git.kernel.dk/linux:
  block: Remove "select SRCU"
  Revert "pktcdvd: remove driver."
  Revert "block: remove devnode callback from struct block_device_operations"
  Revert "block: bio_copy_data_iter"
  ublk: honor IO_URING_F_NONBLOCK for handling control command
  block: don't allow splitting of a REQ_NOWAIT bio
  block: handle bio_split_to_limits() NULL return

Documentation/ABI/testing/debugfs-pktcdvd

@@ -0,0 +1,18 @@
+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

Documentation/ABI/testing/sysfs-class-pktcdvd

@@ -0,0 +1,97 @@
+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

MAINTAINERS

@@ -16610,6 +16610,13 @@ S:	Supported
 F:	Documentation/devicetree/bindings/input/pine64,pinephone-keyboard.yaml
 F:	drivers/input/keyboard/pinephone-keyboard.c
 
+PKTCDVD DRIVER
+M:	linux-block@vger.kernel.org
+S:	Orphan
+F:	drivers/block/pktcdvd.c
+F:	include/linux/pktcdvd.h
+F:	include/uapi/linux/pktcdvd.h
+
 PLANTOWER PMS7003 AIR POLLUTION SENSOR DRIVER
 M:	Tomasz Duszynski <tduszyns@gmail.com>
 S:	Maintained

block/Kconfig

@@ -6,7 +6,6 @@ menuconfig BLOCK
        bool "Enable the block layer" if EXPERT
        default y
        select SBITMAP
-       select SRCU
        help
 	 Provide block layer support for the kernel.
 

block/bio.c

@@ -1401,6 +1401,27 @@ void __bio_advance(struct bio *bio, unsigned bytes)
 }
 EXPORT_SYMBOL(__bio_advance);
 
+void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
+			struct bio *src, struct bvec_iter *src_iter)
+{
+	while (src_iter->bi_size && dst_iter->bi_size) {
+		struct bio_vec src_bv = bio_iter_iovec(src, *src_iter);
+		struct bio_vec dst_bv = bio_iter_iovec(dst, *dst_iter);
+		unsigned int bytes = min(src_bv.bv_len, dst_bv.bv_len);
+		void *src_buf = bvec_kmap_local(&src_bv);
+		void *dst_buf = bvec_kmap_local(&dst_bv);
+
+		memcpy(dst_buf, src_buf, bytes);
+
+		kunmap_local(dst_buf);
+		kunmap_local(src_buf);
+
+		bio_advance_iter_single(src, src_iter, bytes);
+		bio_advance_iter_single(dst, dst_iter, bytes);
+	}
+}
+EXPORT_SYMBOL(bio_copy_data_iter);
+
 /**
  * bio_copy_data - copy contents of data buffers from one bio to another
  * @src: source bio
@@ -1414,21 +1435,7 @@ void bio_copy_data(struct bio *dst, struct bio *src)
 	struct bvec_iter src_iter = src->bi_iter;
 	struct bvec_iter dst_iter = dst->bi_iter;
 
-	while (src_iter.bi_size && dst_iter.bi_size) {
-		struct bio_vec src_bv = bio_iter_iovec(src, src_iter);
-		struct bio_vec dst_bv = bio_iter_iovec(dst, dst_iter);
-		unsigned int bytes = min(src_bv.bv_len, dst_bv.bv_len);
-		void *src_buf = bvec_kmap_local(&src_bv);
-		void *dst_buf = bvec_kmap_local(&dst_bv);
-
-		memcpy(dst_buf, src_buf, bytes);
-
-		kunmap_local(dst_buf);
-		kunmap_local(src_buf);
-
-		bio_advance_iter_single(src, &src_iter, bytes);
-		bio_advance_iter_single(dst, &dst_iter, bytes);
-	}
+	bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
 }
 EXPORT_SYMBOL(bio_copy_data);
 

block/blk-merge.c

@@ -309,6 +309,16 @@ static struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
 	*segs = nsegs;
 	return NULL;
 split:
+	/*
+	 * We can't sanely support splitting for a REQ_NOWAIT bio. End it
+	 * with EAGAIN if splitting is required and return an error pointer.
+	 */
+	if (bio->bi_opf & REQ_NOWAIT) {
+		bio->bi_status = BLK_STS_AGAIN;
+		bio_endio(bio);
+		return ERR_PTR(-EAGAIN);
+	}
+
 	*segs = nsegs;
 
 	/*
@@ -358,11 +368,13 @@ struct bio *__bio_split_to_limits(struct bio *bio,
 	default:
 		split = bio_split_rw(bio, lim, nr_segs, bs,
 				get_max_io_size(bio, lim) << SECTOR_SHIFT);
+		if (IS_ERR(split))
+			return NULL;
 		break;
 	}
 
 	if (split) {
-		/* there isn't chance to merge the splitted bio */
+		/* there isn't chance to merge the split bio */
 		split->bi_opf |= REQ_NOMERGE;
 
 		blkcg_bio_issue_init(split);

block/blk-mq.c

@@ -2951,8 +2951,11 @@ void blk_mq_submit_bio(struct bio *bio)
 	blk_status_t ret;
 
 	bio = blk_queue_bounce(bio, q);
-	if (bio_may_exceed_limits(bio, &q->limits))
+	if (bio_may_exceed_limits(bio, &q->limits)) {
 		bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
+		if (!bio)
+			return;
+	}
 
 	if (!bio_integrity_prep(bio))
 		return;

block/genhd.c

@@ -1201,10 +1201,21 @@ struct class block_class = {
 	.dev_uevent	= block_uevent,
 };
 
+static char *block_devnode(struct device *dev, umode_t *mode,
+			   kuid_t *uid, kgid_t *gid)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	if (disk->fops->devnode)
+		return disk->fops->devnode(disk, mode);
+	return NULL;
+}
+
 const struct device_type disk_type = {
 	.name		= "disk",
 	.groups		= disk_attr_groups,
 	.release	= disk_release,
+	.devnode	= block_devnode,
 };
 
 #ifdef CONFIG_PROC_FS

drivers/block/Kconfig

@@ -285,6 +285,49 @@ config BLK_DEV_RAM_SIZE
 	  The default value is 4096 kilobytes. Only change this if you know
 	  what you are doing.
 
+config CDROM_PKTCDVD
+	tristate "Packet writing on CD/DVD media (DEPRECATED)"
+	depends on !UML
+	depends on SCSI
+	select CDROM
+	help
+	  Note: This driver is deprecated and will be removed from the
+	  kernel in the near future!
+
+	  If you have a CDROM/DVD drive that supports packet writing, say
+	  Y to include support. It should work with any MMC/Mt Fuji
+	  compliant ATAPI or SCSI drive, which is just about any newer
+	  DVD/CD writer.
+
+	  Currently only writing to CD-RW, DVD-RW, DVD+RW and DVDRAM discs
+	  is possible.
+	  DVD-RW disks must be in restricted overwrite mode.
+
+	  See the file <file:Documentation/cdrom/packet-writing.rst>
+	  for further information on the use of this driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called pktcdvd.
+
+config CDROM_PKTCDVD_BUFFERS
+	int "Free buffers for data gathering"
+	depends on CDROM_PKTCDVD
+	default "8"
+	help
+	  This controls the maximum number of active concurrent packets. More
+	  concurrent packets can increase write performance, but also require
+	  more memory. Each concurrent packet will require approximately 64Kb
+	  of non-swappable kernel memory, memory which will be allocated when
+	  a disc is opened for writing.
+
+config CDROM_PKTCDVD_WCACHE
+	bool "Enable write caching"
+	depends on CDROM_PKTCDVD
+	help
+	  If enabled, write caching will be set for the CD-R/W device. For now
+	  this option is dangerous unless the CD-RW media is known good, as we
+	  don't do deferred write error handling yet.
+
 config ATA_OVER_ETH
 	tristate "ATA over Ethernet support"
 	depends on NET

drivers/block/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_AMIGA_Z2RAM)	+= z2ram.o
 obj-$(CONFIG_N64CART)		+= n64cart.o
 obj-$(CONFIG_BLK_DEV_RAM)	+= brd.o
 obj-$(CONFIG_BLK_DEV_LOOP)	+= loop.o
+obj-$(CONFIG_CDROM_PKTCDVD)	+= pktcdvd.o
 obj-$(CONFIG_SUNVDC)		+= sunvdc.o
 
 obj-$(CONFIG_BLK_DEV_NBD)	+= nbd.o

drivers/block/drbd/drbd_req.c

@@ -1607,6 +1607,8 @@ void drbd_submit_bio(struct bio *bio)
 	struct drbd_device *device = bio->bi_bdev->bd_disk->private_data;
 
 	bio = bio_split_to_limits(bio);
+	if (!bio)
+		return;
 
 	/*
 	 * what we "blindly" assume:

drivers/block/ps3vram.c

@@ -587,6 +587,8 @@ static void ps3vram_submit_bio(struct bio *bio)
 	dev_dbg(&dev->core, "%s\n", __func__);
 
 	bio = bio_split_to_limits(bio);
+	if (!bio)
+		return;
 
 	spin_lock_irq(&priv->lock);
 	busy = !bio_list_empty(&priv->list);

drivers/block/ublk_drv.c

@@ -1992,6 +1992,9 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd;
 	int ret = -EINVAL;
 
+	if (issue_flags & IO_URING_F_NONBLOCK)
+		return -EAGAIN;
+
 	ublk_ctrl_cmd_dump(cmd);
 
 	if (!(issue_flags & IO_URING_F_SQE128))

drivers/md/dm.c

@@ -1742,6 +1742,8 @@ static void dm_split_and_process_bio(struct mapped_device *md,
 		 * otherwise associated queue_limits won't be imposed.
 		 */
 		bio = bio_split_to_limits(bio);
+		if (!bio)
+			return;
 	}
 
 	init_clone_info(&ci, md, map, bio, is_abnormal);

drivers/md/md.c

@@ -455,6 +455,8 @@ static void md_submit_bio(struct bio *bio)
 	}
 
 	bio = bio_split_to_limits(bio);
+	if (!bio)
+		return;
 
 	if (mddev->ro == MD_RDONLY && unlikely(rw == WRITE)) {
 		if (bio_sectors(bio) != 0)

drivers/nvme/host/multipath.c

@@ -376,6 +376,8 @@ static void nvme_ns_head_submit_bio(struct bio *bio)
 	 * pool from the original queue to allocate the bvecs from.
 	 */
 	bio = bio_split_to_limits(bio);
+	if (!bio)
+		return;
 
 	srcu_idx = srcu_read_lock(&head->srcu);
 	ns = nvme_find_path(head);

drivers/s390/block/dcssblk.c

@@ -865,6 +865,8 @@ dcssblk_submit_bio(struct bio *bio)
 	unsigned long bytes_done;
 
 	bio = bio_split_to_limits(bio);
+	if (!bio)
+		return;
 
 	bytes_done = 0;
 	dev_info = bio->bi_bdev->bd_disk->private_data;

include/linux/bio.h

@@ -475,6 +475,8 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty);
 extern void bio_set_pages_dirty(struct bio *bio);
 extern void bio_check_pages_dirty(struct bio *bio);
 
+extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
+			       struct bio *src, struct bvec_iter *src_iter);
 extern void bio_copy_data(struct bio *dst, struct bio *src);
 extern void bio_free_pages(struct bio *bio);
 void guard_bio_eod(struct bio *bio);

include/linux/blkdev.h

@@ -1395,6 +1395,7 @@ struct block_device_operations {
 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
 	int (*report_zones)(struct gendisk *, sector_t sector,
 			unsigned int nr_zones, report_zones_cb cb, void *data);
+	char *(*devnode)(struct gendisk *disk, umode_t *mode);
 	/* returns the length of the identifier or a negative errno: */
 	int (*get_unique_id)(struct gendisk *disk, u8 id[16],
 			enum blk_unique_id id_type);

include/linux/pktcdvd.h

@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
+ * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License.  See linux/COPYING for more information.
+ *
+ * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
+ * DVD-RW devices.
+ *
+ */
+#ifndef __PKTCDVD_H
+#define __PKTCDVD_H
+
+#include <linux/blkdev.h>
+#include <linux/completion.h>
+#include <linux/cdrom.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/mempool.h>
+#include <uapi/linux/pktcdvd.h>
+
+/* default bio write queue congestion marks */
+#define PKT_WRITE_CONGESTION_ON    10000
+#define PKT_WRITE_CONGESTION_OFF   9000
+
+
+struct packet_settings
+{
+	__u32			size;		/* packet size in (512 byte) sectors */
+	__u8			fp;		/* fixed packets */
+	__u8			link_loss;	/* the rest is specified
+						 * as per Mt Fuji */
+	__u8			write_type;
+	__u8			track_mode;
+	__u8			block_mode;
+};
+
+/*
+ * Very crude stats for now
+ */
+struct packet_stats
+{
+	unsigned long		pkt_started;
+	unsigned long		pkt_ended;
+	unsigned long		secs_w;
+	unsigned long		secs_rg;
+	unsigned long		secs_r;
+};
+
+struct packet_cdrw
+{
+	struct list_head	pkt_free_list;
+	struct list_head	pkt_active_list;
+	spinlock_t		active_list_lock; /* Serialize access to pkt_active_list */
+	struct task_struct	*thread;
+	atomic_t		pending_bios;
+};
+
+/*
+ * Switch to high speed reading after reading this many kilobytes
+ * with no interspersed writes.
+ */
+#define HI_SPEED_SWITCH 512
+
+struct packet_iosched
+{
+	atomic_t		attention;	/* Set to non-zero when queue processing is needed */
+	int			writing;	/* Non-zero when writing, zero when reading */
+	spinlock_t		lock;		/* Protecting read/write queue manipulations */
+	struct bio_list		read_queue;
+	struct bio_list		write_queue;
+	sector_t		last_write;	/* The sector where the last write ended */
+	int			successive_reads;
+};
+
+/*
+ * 32 buffers of 2048 bytes
+ */
+#if (PAGE_SIZE % CD_FRAMESIZE) != 0
+#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
+#endif
+#define PACKET_MAX_SIZE		128
+#define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
+#define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
+
+enum packet_data_state {
+	PACKET_IDLE_STATE,			/* Not used at the moment */
+	PACKET_WAITING_STATE,			/* Waiting for more bios to arrive, so */
+						/* we don't have to do as much */
+						/* data gathering */
+	PACKET_READ_WAIT_STATE,			/* Waiting for reads to fill in holes */
+	PACKET_WRITE_WAIT_STATE,		/* Waiting for the write to complete */
+	PACKET_RECOVERY_STATE,			/* Recover after read/write errors */
+	PACKET_FINISHED_STATE,			/* After write has finished */
+
+	PACKET_NUM_STATES			/* Number of possible states */
+};
+
+/*
+ * Information needed for writing a single packet
+ */
+struct pktcdvd_device;
+
+struct packet_data
+{
+	struct list_head	list;
+
+	spinlock_t		lock;		/* Lock protecting state transitions and */
+						/* orig_bios list */
+
+	struct bio_list		orig_bios;	/* Original bios passed to pkt_make_request */
+						/* that will be handled by this packet */
+	int			write_size;	/* Total size of all bios in the orig_bios */
+						/* list, measured in number of frames */
+
+	struct bio		*w_bio;		/* The bio we will send to the real CD */
+						/* device once we have all data for the */
+						/* packet we are going to write */
+	sector_t		sector;		/* First sector in this packet */
+	int			frames;		/* Number of frames in this packet */
+
+	enum packet_data_state	state;		/* Current state */
+	atomic_t		run_sm;		/* Incremented whenever the state */
+						/* machine needs to be run */
+	long			sleep_time;	/* Set this to non-zero to make the state */
+						/* machine run after this many jiffies. */
+
+	atomic_t		io_wait;	/* Number of pending IO operations */
+	atomic_t		io_errors;	/* Number of read/write errors during IO */
+
+	struct bio		*r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
+	struct page		*pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
+
+	int			cache_valid;	/* If non-zero, the data for the zone defined */
+						/* by the sector variable is completely cached */
+						/* in the pages[] vector. */
+
+	int			id;		/* ID number for debugging */
+	struct pktcdvd_device	*pd;
+};
+
+struct pkt_rb_node {
+	struct rb_node		rb_node;
+	struct bio		*bio;
+};
+
+struct packet_stacked_data
+{
+	struct bio		*bio;		/* Original read request bio */
+	struct pktcdvd_device	*pd;
+};
+#define PSD_POOL_SIZE		64
+
+struct pktcdvd_device
+{
+	struct block_device	*bdev;		/* dev attached */
+	dev_t			pkt_dev;	/* our dev */
+	char			name[20];
+	struct packet_settings	settings;
+	struct packet_stats	stats;
+	int			refcnt;		/* Open count */
+	int			write_speed;	/* current write speed, kB/s */
+	int			read_speed;	/* current read speed, kB/s */
+	unsigned long		offset;		/* start offset */
+	__u8			mode_offset;	/* 0 / 8 */
+	__u8			type;
+	unsigned long		flags;
+	__u16			mmc3_profile;
+	__u32			nwa;		/* next writable address */
+	__u32			lra;		/* last recorded address */
+	struct packet_cdrw	cdrw;
+	wait_queue_head_t	wqueue;
+
+	spinlock_t		lock;		/* Serialize access to bio_queue */
+	struct rb_root		bio_queue;	/* Work queue of bios we need to handle */
+	int			bio_queue_size;	/* Number of nodes in bio_queue */
+	bool			congested;	/* Someone is waiting for bio_queue_size
+						 * to drop. */
+	sector_t		current_sector;	/* Keep track of where the elevator is */
+	atomic_t		scan_queue;	/* Set to non-zero when pkt_handle_queue */
+						/* needs to be run. */
+	mempool_t		rb_pool;	/* mempool for pkt_rb_node allocations */
+
+	struct packet_iosched   iosched;
+	struct gendisk		*disk;
+
+	int			write_congestion_off;
+	int			write_congestion_on;
+
+	struct device		*dev;		/* sysfs pktcdvd[0-7] dev */
+
+	struct dentry		*dfs_d_root;	/* debugfs: devname directory */
+	struct dentry		*dfs_f_info;	/* debugfs: info file */
+};
+
+#endif /* __PKTCDVD_H */

include/uapi/linux/pktcdvd.h

@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
+ * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License.  See linux/COPYING for more information.
+ *
+ * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
+ * DVD-RW devices.
+ *
+ */
+#ifndef _UAPI__PKTCDVD_H
+#define _UAPI__PKTCDVD_H
+
+#include <linux/types.h>
+
+/*
+ * 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
+ */
+#define PACKET_DEBUG		1
+
+#define	MAX_WRITERS		8
+
+#define PKT_RB_POOL_SIZE	512
+
+/*
+ * How long we should hold a non-full packet before starting data gathering.
+ */
+#define PACKET_WAIT_TIME	(HZ * 5 / 1000)
+
+/*
+ * use drive write caching -- we need deferred error handling to be
+ * able to successfully recover with this option (drive will return good
+ * status as soon as the cdb is validated).
+ */
+#if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
+#define USE_WCACHING		1
+#else
+#define USE_WCACHING		0
+#endif
+
+/*
+ * No user-servicable parts beyond this point ->
+ */
+
+/*
+ * device types
+ */
+#define PACKET_CDR		1
+#define	PACKET_CDRW		2
+#define PACKET_DVDR		3
+#define PACKET_DVDRW		4
+
+/*
+ * flags
+ */
+#define PACKET_WRITABLE		1	/* pd is writable */
+#define PACKET_NWA_VALID	2	/* next writable address valid */
+#define PACKET_LRA_VALID	3	/* last recorded address valid */
+#define PACKET_MERGE_SEGS	4	/* perform segment merging to keep */
+					/* underlying cdrom device happy */
+
+/*
+ * Disc status -- from READ_DISC_INFO
+ */
+#define PACKET_DISC_EMPTY	0
+#define PACKET_DISC_INCOMPLETE	1
+#define PACKET_DISC_COMPLETE	2
+#define PACKET_DISC_OTHER	3
+
+/*
+ * write type, and corresponding data block type
+ */
+#define PACKET_MODE1		1
+#define PACKET_MODE2		2
+#define PACKET_BLOCK_MODE1	8
+#define PACKET_BLOCK_MODE2	10
+
+/*
+ * Last session/border status
+ */
+#define PACKET_SESSION_EMPTY		0
+#define PACKET_SESSION_INCOMPLETE	1
+#define PACKET_SESSION_RESERVED		2
+#define PACKET_SESSION_COMPLETE		3
+
+#define PACKET_MCN			"4a656e734178626f65323030300000"
+
+#undef PACKET_USE_LS
+
+#define PKT_CTRL_CMD_SETUP	0
+#define PKT_CTRL_CMD_TEARDOWN	1
+#define PKT_CTRL_CMD_STATUS	2
+
+struct pkt_ctrl_command {
+	__u32 command;				/* in: Setup, teardown, status */
+	__u32 dev_index;			/* in/out: Device index */
+	__u32 dev;				/* in/out: Device nr for cdrw device */
+	__u32 pkt_dev;				/* in/out: Device nr for packet device */
+	__u32 num_devices;			/* out: Largest device index + 1 */
+	__u32 padding;				/* Not used */
+};
+
+/*
+ * packet ioctls
+ */
+#define PACKET_IOCTL_MAGIC	('X')
+#define PACKET_CTRL_CMD		_IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)
+
+
+#endif /* _UAPI__PKTCDVD_H */