[dm-devel] [PATCH] multipath: Retry host transient errors for rdac checker
Christophe Varoqui
christophe.varoqui at gmail.com
Mon Mar 7 23:00:54 UTC 2011
On mar., 2011-03-01 at 12:08 -0700, Moger, Babu wrote:
> Sometimes if the host is in transient state, we need to wait till the devloss timeout to
> expire before switching path group. We have seen in some cases path group switch happens
> even before the devloss timeout expire. This patch fixes the problem for rdac checker..
>
I did not see comments on this patch.
It's now applied upstream.
--
Christophe Varoqui <christophe.varoqui at opensvc.com>
OpenSVC
> Signed-off-by: Babu Moger <babu.moger at lsi.com>
> ---
> --- multipath-tools/libmultipath/checkers/rdac.c.orig 2011-02-16 13:58:06.000000000 -0600
> +++ multipath-tools/libmultipath/checkers/rdac.c 2011-02-17 12:01:23.000000000 -0600
> @@ -48,7 +48,9 @@
> unsigned char inqCmdBlk[INQUIRY_CMDLEN] = { INQUIRY_CMD, 1, 0, 0, 0, 0 };
> unsigned char sense_b[SENSE_BUFF_LEN];
> struct sg_io_hdr io_hdr;
> + int retry_rdac = 5;
>
> +retry:
> inqCmdBlk[2] = (unsigned char) pg_op;
> inqCmdBlk[4] = (unsigned char) (mx_resp_len & 0xff);
> memset(&io_hdr, 0, sizeof (struct sg_io_hdr));
> @@ -72,6 +74,22 @@
> if ((0 == io_hdr.status) && (0 == io_hdr.host_status) &&
> (0 == io_hdr.driver_status))
> return 0;
> +
> + /* check if we need to retry this error */
> + if (io_hdr.info & SG_INFO_OK_MASK) {
> + switch (io_hdr.host_status) {
> + case DID_BUS_BUSY:
> + case DID_ERROR:
> + case DID_TRANSPORT_DISRUPTED:
> + /* Transport error, retry */
> + if (--retry_rdac)
> + goto retry;
> + break;
> + default:
> + break;
> + }
> + }
> +
> if ((SCSI_CHECK_CONDITION == io_hdr.status) ||
> (SCSI_COMMAND_TERMINATED == io_hdr.status) ||
> (SG_ERR_DRIVER_SENSE == (0xf & io_hdr.driver_status))) {
>
>
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