On Monday, April 20, 2009 10:39 AM, Grant Grundler wrote: > > u8 is_logical_volume; /* is > this logical volume */ > > "is this logical volume" comment is just repeating the > variable name. :) > Maybe point at a description (e.g. "See page XX of Programmers Guide") > or omit this comment. This is a boolean variable meaning whether the device object is a raid volume or not. If its a raid volume, this is set to 1. If its not a raid volume, this is set to zero. When its set to zero, then it means the device could be bare drive, hidden raid component, or some other periphial like tape, cdrom, etc. > > > + /* this belongs to volume */ > > + u8 is_hidden_raid_component; > > Does "belongs to a volume" mean a "logical volume"? This is a boolean variable meaning whether the device object is a hidden raid component. A hidden raid component is a drive belonging to a raid volume set. > > Suggestion: replace with something like /* is physical dev > part of volume? */ > > > + /* this valid when is_hidden_raid_component set */ > > + u8 volume_id; > > When looking at code, I would have associated volume_id > with "is_logical_volume" variable. Maybe call this "hidden_raid_VID" ? This is the target id for the volume when the device object happens to be a hidden raid component. > > > + /* cached data for a removed device */ > > + u8 is_cached; > > "cached data" generally refers to user payload data. > I'm pretty sure that's not meant here. > Suggestion: /* Device info is cached (or not) */ > > It's interesting to know this if the device has been removed. > But the act of caching has to take place before the device is > gone and thus, this flag will tell us the data was > read once "before" and may not be current. > > Some devices will change the SCSI model string after > they've spun up and loaded the full firmware from reserved > tracks on the media. > No it doesn't mean that. What this variable means that this device object is still live in the link list after the bare drive has been deleted, hence the data for this object is cached. The reason we are caching the device object is due to a customer request. This particular customer want us to support reporting hidden raid components after then have been removed. They want their storage apps to report this information so the service support reps can identify which drive was pulled or failed. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
