[PATCH] pktcdvd: add sysfs and debugfs interface

Add a sysfs and debugfs interface to the pktcdvd driver.

Look into the Documentation/ABI/testing/* files in the patch for more info.
Signed-off-by: Thomas Maier <balagi@justmail.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/ABI/testing/debugfs-pktcdvd

+What:           /debug/pktcdvd/pktcdvd[0-7]
+Date:           Oct. 2006
+KernelVersion:  2.6.19
+Contact:        Thomas Maier <balagi@justmail.de>
+Description:
+
+debugfs interface
+-----------------
+
+The pktcdvd module (packet writing driver) creates
+these files in debugfs:
+
+/debug/pktcdvd/pktcdvd[0-7]/
+    info            (0444) Lots of human readable driver
+                           statistics and infos. Multiple lines!
+
+Example:
+-------
+
+cat /debug/pktcdvd/pktcdvd0/info

Documentation/ABI/testing/sysfs-class-pktcdvd

+What:           /sys/class/pktcdvd/
+Date:           Oct. 2006
+KernelVersion:  2.6.19
+Contact:        Thomas Maier <balagi@justmail.de>
+Description:
+
+sysfs interface
+---------------
+
+The pktcdvd module (packet writing driver) creates
+these files in the sysfs:
+(<devid> is in format  major:minor )
+
+/sys/class/pktcdvd/
+    add            (0200)  Write a block device id (major:minor)
+                           to create a new pktcdvd device and map
+                           it to the block device.
+
+    remove         (0200)  Write the pktcdvd device id (major:minor)
+                           to it to remove the pktcdvd device.
+
+    device_map     (0444)  Shows the device mapping in format:
+                             pktcdvd[0-7] <pktdevid> <blkdevid>
+
+/sys/class/pktcdvd/pktcdvd[0-7]/
+    dev                   (0444) Device id
+    uevent                (0200) To send an uevent.
+
+/sys/class/pktcdvd/pktcdvd[0-7]/stat/
+    packets_started       (0444) Number of started packets.
+    packets_finished      (0444) Number of finished packets.
+
+    kb_written            (0444) kBytes written.
+    kb_read               (0444) kBytes read.
+    kb_read_gather        (0444) kBytes read to fill write packets.
+
+    reset                 (0200) Write any value to it to reset
+                                 pktcdvd device statistic values, like
+                                 bytes read/written.
+
+/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/
+    size                  (0444) Contains the size of the bio write
+                                 queue.
+
+    congestion_off        (0644) If bio write queue size is below
+                                 this mark, accept new bio requests
+                                 from the block layer.
+
+    congestion_on         (0644) 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

Documentation/cdrom/packet-writing.txt

@@ -90,6 +90,41 @@ Notes
   to create an ext2 filesystem on the disc.
 
 
+Using the pktcdvd sysfs interface
+---------------------------------
+
+Since Linux 2.6.19, the pktcdvd module has a sysfs interface
+and can be controlled by it. For example the "pktcdvd" tool uses
+this interface. (see http://people.freenet.de/BalaGi#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-block-pktcdvd
+
+
+Using the pktcdvd debugfs interface
+-----------------------------------
+
+To read pktcdvd device infos in human readable form, do:
+
+	# cat /debug/pktcdvd/pktcdvd[0-7]/info
+
+For a description of the debugfs interface look into the file:
+
+  Documentation/ABI/testing/debugfs-pktcdvd
+
+
+
 Links
 -----
 

include/linux/pktcdvd.h

@@ -111,7 +111,8 @@ struct pkt_ctrl_command {
 #include <linux/blkdev.h>
 #include <linux/completion.h>
 #include <linux/cdrom.h>
-
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
 
 /* default bio write queue congestion marks */
 #define PKT_WRITE_CONGESTION_ON    10000
@@ -247,6 +248,14 @@ struct packet_stacked_data
 };
 #define PSD_POOL_SIZE		64
 
+struct pktcdvd_kobj
+{
+	struct kobject		kobj;
+	struct pktcdvd_device	*pd;
+};
+#define to_pktcdvdkobj(_k) \
+  ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))
+
 struct pktcdvd_device
 {
 	struct block_device	*bdev;		/* dev attached */
@@ -280,6 +289,13 @@ struct pktcdvd_device
 
 	int			write_congestion_off;
 	int			write_congestion_on;
+
+	struct class_device	*clsdev;	/* sysfs pktcdvd[0-7] class dev */
+	struct pktcdvd_kobj	*kobj_stat;	/* sysfs pktcdvd[0-7]/stat/     */
+	struct pktcdvd_kobj	*kobj_wqueue;	/* sysfs pktcdvd[0-7]/write_queue/ */
+
+	struct dentry		*dfs_d_root;	/* debugfs: devname directory */
+	struct dentry		*dfs_f_info;	/* debugfs: info file */
 };
 
 #endif /* __KERNEL__ */