[RFC][PATCH] never scan a device which is using the error target

On 10/24/2010 02:55 AM, Mike Snitzer wrote:
> A merged snapshot's DM device is made to use the "error" target as part
> of lvm's transaction to merge a snapshot.  This snapshot merge use-case
> aside, any device using the error target shouldn't be scanned.
> 
> NOTE: I'm not using an ignore_suspended_devices() check like other
> target checks in device_is_usable() -- its not clear to me what such a

IIRC scan for mirrors, snapshots etc is OK.
But during mirror repair or conversion some devices in the middle of stack
can be suspended, so the ignore_suspended_devices() says when it is safe to
scan it. (see that it is set during conversions etc)
IMHO it is quite hack (mainly for clusters where one node runs the conversion
or repair and other just follows the state).

For error device it makes no sense - it is unusable all the time:-)

> +		if (target_type && !strcmp(target_type, "error")) {

Do we have some #define for the error target name?

Anyway, ack.

Milan