linux-toradex.git/drivers/block/rbd.c, branch v3.7

rbd: BUG on invalid layout

2012-10-01T22:20:00+00:00

This shouldn't actually be possible because the layout struct is
constructed from the RBD header and validated then.

[elder@inktank.com: converted BUG() call to equivalent rbd_assert()]

Signed-off-by: Sage Weil 
Reviewed-by: Alex Elder

rbd: update remaining header fields for v2

2012-10-01T19:30:54+00:00

There are three fields that are not yet updated for format 2 rbd
image headers:  the version of the header object; the encryption
type; and the compression type.  There is no interface defined for
fetching the latter two, so just initialize them explicitly to 0 for
now.

Change rbd_dev_v2_snap_context() so the caller can be supplied the
version for the header object.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: get snapshot name for a v2 image

2012-10-01T19:30:54+00:00

Define rbd_dev_v2_snap_name() to fetch the name for a particular
snapshot in a format 2 rbd image.

Define rbd_dev_v2_snap_info() to to be a wrapper for getting the
name, size, and features for a particular snapshot, using an
interface that matches the equivalent function for version 1 images.

Define rbd_dev_snap_info() wrapper function and use it to call the
appropriate function for getting the snapshot name, size, and
features, dependent on the rbd image format.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: get the snapshot context for a v2 image

2012-10-01T19:30:53+00:00

Fetch the snapshot context for an rbd format 2 image by calling
the "get_snapcontext" method on its header object.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: get image features for a v2 image

2012-10-01T19:30:53+00:00

The features values for an rbd format 2 image are fetched from the
server using a "get_features" method.  The same method is used for
getting the features for a snapshot, so structure this addition with
a generic helper routine that can get this information for either.

The server will provide two 64-bit feature masks, one representing
the features potentially in use for this image (or its snapshot),
and one representing features that must be supported by the client
in order to work with the image.

For the time being, neither of these is really used so we keep
things simple and just record the first feature vector.  Once we
start using these feature masks, what we record and what we expose
to the user will most likely change.

Signed-off-by: Alex Elder

rbd: get the object prefix for a v2 rbd image

2012-10-01T19:30:53+00:00

The object prefix of an rbd format 2 image is fetched from the
server using a "get_object_prefix" method.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: add code to get the size of a v2 rbd image

2012-10-01T19:30:53+00:00

The size of an rbd format 2 image is fetched from the server using a
"get_size" method.  The same method is used for getting the size of
a snapshot, so structure this addition with a generic helper routine
that we can get this information for either.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: lay out header probe infrastructure

2012-10-01T19:30:53+00:00

This defines a new function rbd_dev_probe() as a top-level
function for populating detailed information about an rbd device.

It first checks for the existence of a format 2 rbd image id object.
If it exists, the image is assumed to be a format 2 rbd image, and
another function rbd_dev_v2() is called to finish populating
header data for that image.  If it does not exist, it is assumed to
be an old (format 1) rbd image, and calls a similar function
rbd_dev_v1() to populate its header information.

A new field, rbd_dev->format, is defined to record which version
of the rbd image format the device represents.  For a valid mapped
rbd device it will have one of two values, 1 or 2.

So far, the format 2 images are not really supported; this is
laying out the infrastructure for fleshing out that support.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: encapsulate code that gets snapshot info

2012-10-01T19:30:53+00:00

Create a function that encapsulates looking up the name, size and
features related to a given snapshot, which is indicated by its
index in an rbd device's snapshot context array of snapshot ids.

This interface will be used to hide differences between the format 1
and format 2 images.

At the moment this (looking up the name anyway) is slightly less
efficient than what's done currently, but we may be able to optimize
this a bit later on by cacheing the last lookup if it proves to be a
problem.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

rbd: add an rbd features field

2012-10-01T19:30:53+00:00

Record the features values for each rbd image and each of its
snapshots.  This is really something that only becomes meaningful
for version 2 images, so this is just putting in place code
that will form common infrastructure.

It may be useful to expand the sysfs entries--and therefore the
information we maintain--for the image and for each snapshot.
But I'm going to hold off doing that until we start making
active use of the feature bits.

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin