Re: [PATCH 1/2] tcm_vhost: Wait for pending requests in vhost_scsi_flush()

[Paolo Bonzini <pbonzini@redhat.com>]

Il 11/03/2013 06:09, Asias He ha scritto:
> This patch makes vhost_scsi_flush() wait for all the pending requests
> issued before the flush operation to be finished.

There is no protection against issuing concurrent flush operations.  If
we later would like to make the flush a ioctl (for example for migration
purposes), it would be confusing, and I'm not sure how you could extend
the during_flush machinery.

What about making vhost_scsi_flush() wait for all pending requests,
including those issues during the flush operation?  Then you can easily
support concurrent flushes; just add a waitqueue and wake_up_all at the
end of the flush operation.

BTW, adding such a ioctl as part of this patch would probably be a good
thing to do anyway.

Paolo