+
+ /* register with device with a supported BM */
+ list_for_each_entry(bt, &nvm_bms, list) {
+ ret = bt->register_bm(dev);
+ if (ret < 0)
+ goto err; /* initialization failed */
+ if (ret > 0) {
+ dev->bm = bt;
+ break; /* successfully initialized */
+ }
+ }
Why just search it from head to tail? Can user specific it
in nvm_create_target()?
Hi Yang,
Currently only the rrpc and a couple of out of tree block managers are
built. The register_bm only tries to find a block manager that supports
the device, when it finds it, that one is initialized. It is an open
question on how we choose the right block manager, e.g. a proprietary
and a open-source block manager is in place. Priorities might be a way
to go? or mark certain block managers as a catch all?
Hopefully we will get away with only a single or two block managers in
the future, so we won't have one for each type of device.
+
+ if (!ret) {
+ pr_info("nvm: no compatible bm was found.\n");
+ return 0;
+ }
If we allow nvm_device registered with no bm, we would get
a NULL pointer reference problem in later using.
Yes, definitely.
In the care that happens, I envision it should be
possible to register a block manager after a device is loaded, and then
any outstanding devices (which does not have a registered block
manager), will be probed again.
As mentioned above, why we have to choose bm for nvm in nvm_register?
Without a block manager, we don't know the structure of the device and
how to interact with it. I want to initialize that as soon as possible.
So that layers on top can start interacting.
.
Thanx
Yang