On 14/03/2026 04:48, Benjamin Marzinski wrote:
+ ext_hdr_unsupp = true;
+ goto retry;
+ }
+ /*
+ * If the array returns with 'ALUA state transition'
+ * sense code here it cannot return RTPG data during
+ * transition. So set the state to 'transitioning' directly.
+ */
+ if (sense_hdr.sense_key == NOT_READY &&
+ sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
+ goto out;
This check is odd. First, we don't set the state to 'transitioning' like
the comment says. We don't set alua_state at all, which ends up meaning
that it stays as 0 (SCSI_ACCESS_STATE_OPTIMAL). It seems like we should
explicitly set it and make the comment reflect that, if just to aid
understanding of the logic.
Yeah, I have to admit that this is all bodged the a bit, as
transitioning is not properly handled. Instead of "basic" ALUA support,
this really is limited ALUA support.
I am now looking at a way to have a core scsi ALUA driver to handle all
of this, but it is challenging as we need to continue ALUA DH support.
Nitpick: Also, this is the only place where we goto out. All the other
checks individually free the buffer and return directly. I realize that
all the other checks that exit early are errors, but it seems like we
could just return a variable at the end of the function.
Sure, I can pay attention to this. However, as mentioned above, I am
experimenting with moving any ALUA specifics into scsi core code.
+
+ /*
+ * Retry on any other UNIT ATTENTION occurred.
+ */
+ if (sense_hdr.sense_key == UNIT_ATTENTION) {
+ scsi_print_sense_hdr(sdev, __func__, &sense_hdr);
+ kfree(buff);
+ return -EAGAIN;
+ }
If we get a UNIT ATTENTION, we end up failing scsi_mpath_dev_alloc(),
not retrying. Aside from the comment being wrong, it seems very brittle
to fail here, just because we got a UNIT ATTENTION.
Ack
Thanks,
John
