[sheepdog] [PATCH] sheep: fix a bug that hangs the cluster during recovery

[Liu Yuan]

On 08/27/2012 06:45 PM, levin li wrote:
> During recovery, a VDI creation request may waits for recovery
> to complete, and VDI creation request is a cluster request which
> prevent other cluster requests being processed, when recovery comes
> to notify_recovery_completion_work, it issues another cluster request
> with SD_OP_COMPLETE_RECOVERY which is blocked by VDI creation, and
> as result, notify_recovery_completion_work blocks the recovery_wqueue,
> if a new recovery comes, it's blocked, at the same time, a VDI creation
> request may waits for this recovery to complete, so it's a dead lock.

With this patch, we can pass 026 again. Applied.

Thanks,
Yuan