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1sysfs interface
2---------------
3The pktcdvd module (packet writing driver) creates the following files in the
4sysfs: (<devid> is in the format major:minor)
5
6What: /sys/class/pktcdvd/add
7What: /sys/class/pktcdvd/remove
8What: /sys/class/pktcdvd/device_map
9Date: Oct. 2006
10KernelVersion: 2.6.20
11Contact: Thomas Maier <balagi@justmail.de>
12Description:
13
14 ========== ==============================================
15 add (WO) Write a block device id (major:minor) to
16 create a new pktcdvd device and map it to the
17 block device.
18
19 remove (WO) Write the pktcdvd device id (major:minor)
20 to remove the pktcdvd device.
21
22 device_map (RO) Shows the device mapping in format:
23 pktcdvd[0-7] <pktdevid> <blkdevid>
24 ========== ==============================================
25
26
27What: /sys/class/pktcdvd/pktcdvd[0-7]/dev
28What: /sys/class/pktcdvd/pktcdvd[0-7]/uevent
29Date: Oct. 2006
30KernelVersion: 2.6.20
31Contact: Thomas Maier <balagi@justmail.de>
32Description:
33 dev: (RO) Device id
34
35 uevent: (WO) To send a uevent
36
37
38What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_started
39What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_finished
40What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_written
41What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read
42What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read_gather
43What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/reset
44Date: Oct. 2006
45KernelVersion: 2.6.20
46Contact: Thomas Maier <balagi@justmail.de>
47Description:
48 packets_started: (RO) Number of started packets.
49
50 packets_finished: (RO) Number of finished packets.
51
52 kb_written: (RO) kBytes written.
53
54 kb_read: (RO) kBytes read.
55
56 kb_read_gather: (RO) kBytes read to fill write packets.
57
58 reset: (WO) Write any value to it to reset
59 pktcdvd device statistic values, like
60 bytes read/written.
61
62
63What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/size
64What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_off
65What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_on
66Date: Oct. 2006
67KernelVersion: 2.6.20
68Contact: Thomas Maier <balagi@justmail.de>
69Description:
70 ============== ================================================
71 size (RO) Contains the size of the bio write queue.
72
73 congestion_off (RW) If bio write queue size is below this mark,
74 accept new bio requests from the block layer.
75
76 congestion_on (RW) If bio write queue size is higher as this
77 mark, do no longer accept bio write requests
78 from the block layer and wait till the pktcdvd
79 device has processed enough bio's so that bio
80 write queue size is below congestion off mark.
81 A value of <= 0 disables congestion control.
82 ============== ================================================
83
84
85Example:
86--------
87To use the pktcdvd sysfs interface directly, you can do::
88
89 # create a new pktcdvd device mapped to /dev/hdc
90 echo "22:0" >/sys/class/pktcdvd/add
91 cat /sys/class/pktcdvd/device_map
92 # assuming device pktcdvd0 was created, look at stat's
93 cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written
94 # print the device id of the mapped block device
95 fgrep pktcdvd0 /sys/class/pktcdvd/device_map
96 # remove device, using pktcdvd0 device id 253:0
97 echo "253:0" >/sys/class/pktcdvd/remove
1What: /sys/class/pktcdvd/
2Date: Oct. 2006
3KernelVersion: 2.6.20
4Contact: Thomas Maier <balagi@justmail.de>
5Description:
6
7sysfs interface
8---------------
9
10The pktcdvd module (packet writing driver) creates
11these files in the sysfs:
12(<devid> is in format major:minor )
13
14/sys/class/pktcdvd/
15 add (0200) Write a block device id (major:minor)
16 to create a new pktcdvd device and map
17 it to the block device.
18
19 remove (0200) Write the pktcdvd device id (major:minor)
20 to it to remove the pktcdvd device.
21
22 device_map (0444) Shows the device mapping in format:
23 pktcdvd[0-7] <pktdevid> <blkdevid>
24
25/sys/class/pktcdvd/pktcdvd[0-7]/
26 dev (0444) Device id
27 uevent (0200) To send an uevent.
28
29/sys/class/pktcdvd/pktcdvd[0-7]/stat/
30 packets_started (0444) Number of started packets.
31 packets_finished (0444) Number of finished packets.
32
33 kb_written (0444) kBytes written.
34 kb_read (0444) kBytes read.
35 kb_read_gather (0444) kBytes read to fill write packets.
36
37 reset (0200) Write any value to it to reset
38 pktcdvd device statistic values, like
39 bytes read/written.
40
41/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/
42 size (0444) Contains the size of the bio write
43 queue.
44
45 congestion_off (0644) If bio write queue size is below
46 this mark, accept new bio requests
47 from the block layer.
48
49 congestion_on (0644) If bio write queue size is higher
50 as this mark, do no longer accept
51 bio write requests from the block
52 layer and wait till the pktcdvd
53 device has processed enough bio's
54 so that bio write queue size is
55 below congestion off mark.
56 A value of <= 0 disables congestion
57 control.
58
59
60Example:
61--------
62To use the pktcdvd sysfs interface directly, you can do:
63
64# create a new pktcdvd device mapped to /dev/hdc
65echo "22:0" >/sys/class/pktcdvd/add
66cat /sys/class/pktcdvd/device_map
67# assuming device pktcdvd0 was created, look at stat's
68cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written
69# print the device id of the mapped block device
70fgrep pktcdvd0 /sys/class/pktcdvd/device_map
71# remove device, using pktcdvd0 device id 253:0
72echo "253:0" >/sys/class/pktcdvd/remove