Struct devicemapper::LinearDev

pub struct LinearDev { /* fields omitted */ }

A DM construct of combined Segments

Methods

impl LinearDev

Use DM to concatenate a list of segments together into a linear block device of continuous sectors.

fn setup(
    dm: &DM,
    name: &DmName,
    uuid: Option<&DmUuid>,
    segments: &[Segment]
) -> DmResult<LinearDev>

Construct a new block device by concatenating the given segments into linear space. If the device is already known to the kernel, just verifies that the segments argument passed exactly matches the kernel data.

Warning: If the segments overlap, this method will succeed. However, the behavior of the linear device in that case should be treated as undefined.

Note: A linear device is just a mapping in the kernel from locations in that device to locations on other devices which are specified by their device number. There is usually a device node so that data can be read from and written to the device. Other than that, it really has no existence. Consequently, there is no conflict in overloading this method to mean both "make a wholly new device" and "establish the existence of the requested device". Of course, a linear device is usually expected to hold data, so it is important to get the mapping just right.

fn segments(&self) -> &[Segment]

Return a reference to the segments that back this linear device.

fn set_segments(&mut self, dm: &DM, segments: &[Segment]) -> DmResult<()>

Set the segments for this linear device. Warning: It is the client's responsibility to make sure the designated segments are compatible with the device's existing segments. If they are not, this function will still succeed, but some kind of data corruption will be the inevitable result.

fn set_name(&mut self, dm: &DM, name: &DmName) -> DmResult<()>

Set the name for this LinearDev.

Trait Implementations

impl Debug for LinearDev

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl DmDevice for LinearDev

fn device(&self) -> Device

The device.

fn devnode(&self) -> PathBuf

The device's device node.

fn name(&self) -> &DmName

The device's name.

fn size(&self) -> Sectors

The number of sectors available for user data.

fn teardown(self, dm: &DM) -> DmResult<()>

Erase the kernel's memory of this device.