| 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 |
