On 07/11/2012 03:25 PM, Alex Elder wrote:
On 07/11/2012 02:36 PM, Josh Durgin wrote:
On 07/11/2012 07:02 AM, Alex Elder wrote:
An rbd device's pool name is used to specify the pool to use for an
rbd image when it gets mapped (via rbd_add()). However, only the
pool id can be relied on to be invariant--the name of a pool can
change at any time.
This means that the name of the pool is potentially stale as soon as
the image is mapped, so it's a bad idea to record this information.
So only store the pool id, not its name, in an rbd_dev.
Here are a few specific notes about this change:
- The "pool" name device attribute (/sys/bus/rbd/devices/<N>/pool)
goes away. In its place is a "pool_id" attribute that provide
the numeric pool id for the rbd image.
We're using the pool name for udev to provide a predictable device name
(/dev/rbd/poolname/imagename[@snapname]), so we probably want to keep
the sysfs attribute. I don't think there's a good way for us to detect
pool renames right now though, so we should document that the pool
name reported does not reflect any potential renames.
OK. I'll put the "pool" name entry back, but will still include the
new "pool_id" entry as well. Do you want me to re-post after that,
or can I consider this reviewed?
Consider it reviewed. The same goes for the rest of this series,
since it was just minor changes.
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