blob: b1c3f0263359150017e37081baa5f0aeb01c2121 [file] [log] [blame]
What: /sys/class/pktcdvd/
Date: Oct. 2006
KernelVersion: 2.6.20
Contact: Thomas Maier <>
sysfs interface
The pktcdvd module (packet writing driver) creates
these files in the sysfs:
(<devid> is in format major:minor )
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>
dev (0444) Device id
uevent (0200) To send an uevent.
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.
size (0444) Contains the size of the bio write
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
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