[dm-devel] [PATCH 1/1] multipath-tools: Change path checker for IBM IPR devices
Christoph Hellwig
hch at infradead.org
Thu Sep 25 16:57:43 UTC 2014
On Thu, Sep 25, 2014 at 11:47:42AM -0500, Brian King wrote:
> The issue we've run into started when this patch started making its
> way into distros:
>
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/scsi/scsi_error.c?id=14216561e164671ce147458653b1fea06a4ada1e
>
> That changed the behaviour for user initiated TUR commands. After an ipr
> adapter gets reset, all disk array devices require a start unit command
> to be issued to them before they will accept commands. So, with the SCSI
> EH change, we now end up in a scenario with dual ipr adapters where the
> TUR getting issued from the health checker returns with a Not Ready response
> and since SCSI EH no longer triggers the Start Unit in this scenario,
> the path never recovers.
>
> The alternative solution would be to change the TUR path checker in multipath-tools
> to issue a Start Unit if it sees a 02/04/02.
Or we could fix up the check introduced by the commit, with something
ala:
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index a2c3d3d..7228d9e 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -459,13 +459,18 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
if (! scsi_command_normalize_sense(scmd, &sshdr))
return FAILED; /* no valid sense data */
- if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
+ if (scmd->cmnd[0] == TEST_UNIT_READY &&
+ scmd->request->cmd_type == REQ_TYPE_FS &&
+ scmd->scsi_done != scsi_eh_done) {
/*
* nasty: for mid-layer issued TURs, we need to return the
* actual sense data without any recovery attempt. For eh
- * issued ones, we need to try to recover and interpret
+ * issued ones, we need to try to recover and interpret,
+ * and for pass through TURs we just need to stay out of the
+ * way, so that the device handlers can do the right thing.
*/
return SUCCESS;
+ }
scsi_report_sense(sdev, &sshdr);
>
> Thanks,
>
> Brian
>
> --
> Brian King
> Power Linux I/O
> IBM Linux Technology Center
>
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
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