On Tue, Apr 07, 2015 at 07:21:06AM -0700, Christoph Hellwig wrote:
> On Tue, Apr 07, 2015 at 08:09:00AM -0400, Dan Lane wrote:
> > Thanks, but unfortunately your post doesn't have any replies either... Any
> > idea of how I could work around or fix this?
>
> I don't really know the COMPARE AND WRITE code at all, so I can't really
> help with fixing it.
>
> You could try to crudely disable it like in the patch below and hope
> that the initiator has a fallback:
Just removing the caw_sem makes the test complete, although of course
that means the COMPARE AND WRITE won't actually be atomic.
I think this code really needs a conersion to a proper state machine
instead of a pile of hacks and flags.
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 3e72974..14ea2f6 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -394,7 +394,7 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
* Unlock ->caw_sem originally obtained during sbc_compare_and_write()
* before the original READ I/O submission.
*/
- up(&dev->caw_sem);
+// up(&dev->caw_sem);
return TCM_NO_SENSE;
}
@@ -537,7 +537,7 @@ out:
* In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
* sbc_compare_and_write() before the original READ I/O submission.
*/
- up(&dev->caw_sem);
+// up(&dev->caw_sem);
kfree(write_sg);
kfree(buf);
return ret;
@@ -553,11 +553,11 @@ sbc_compare_and_write(struct se_cmd *cmd)
* Submit the READ first for COMPARE_AND_WRITE to perform the
* comparision using SGLs at cmd->t_bidi_data_sg..
*/
- rc = down_interruptible(&dev->caw_sem);
- if ((rc != 0) || signal_pending(current)) {
- cmd->transport_complete_callback = NULL;
- return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- }
+// rc = down_interruptible(&dev->caw_sem);
+// if ((rc != 0) || signal_pending(current)) {
+// cmd->transport_complete_callback = NULL;
+// return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+// }
/*
* Reset cmd->data_length to individual block_size in order to not
* confuse backend drivers that depend on this value matching the
@@ -569,7 +569,7 @@ sbc_compare_and_write(struct se_cmd *cmd)
DMA_FROM_DEVICE);
if (ret) {
cmd->transport_complete_callback = NULL;
- up(&dev->caw_sem);
+// up(&dev->caw_sem);
return ret;
}
/*
--
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