On 6/7/23 08:38, Martin Wilck wrote:
On Wed, 2023-06-07 at 07:05 -0700, Bart Van Assche wrote:
On 6/7/23 02:26, Martin Wilck wrote:
On Wed, 2023-06-07 at 07:27 +0200, Christoph Hellwig wrote:
On Tue, Jun 06, 2023 at 09:38:45PM +0200, mwilck@xxxxxxxx wrote:
scsi_target_block(struct device *dev)
{
+ struct Scsi_Host *shost = dev_to_shost(dev);
+
if (scsi_is_target_device(dev))
starget_for_each_device(to_scsi_target(dev),
NULL,
device_block);
else
device_for_each_child(dev, NULL,
target_block);
+
+ /* Wait for ongoing scsi_queue_rq() calls to finish. */
+ if (!WARN_ON_ONCE(!shost))
How could host ever be NULL here? I can't see why we'd want this
check.
The reason is simple: I wasn't certain if dev_to_shost() could
return
NULL, and preferred skipping the wait over an Oops. I hear you say
that
dev_to_shost() can't go wrong, so I'll remove the NULL test.
I propose to pass shost as the first argument to scsi_target_block()
instead of using dev_to_shost() inside scsi_target_block(). Except in
__iscsi_block_session(), shost is already available as a local
variable.
If we do this, it might actually be cleaner to just pass the tag set to
wait for.
Wouldn't that be close to a layering violation? Shouldn't SCSI APIs accept
pointers to SCSI objects instead of pointers to block layer abstractions?
Thanks,
Bart.
