On Fri, Oct 12, 2018 at 12:26:59AM +0200, Martin Wilck wrote:
> A checker shouldn't set the path state to PATH_DOWN if it fails
> to obtain information about the path in the first place. Add logic
> to the checker to distinguish a failed path from an unsupported path.
>
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> libmultipath/checkers/emc_clariion.c | 50 ++++++++++++++++++++++++++--
> 1 file changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/libmultipath/checkers/emc_clariion.c b/libmultipath/checkers/emc_clariion.c
> index f8e55b93..a277a004 100644
> --- a/libmultipath/checkers/emc_clariion.c
> +++ b/libmultipath/checkers/emc_clariion.c
> @@ -20,6 +20,11 @@
> #define INQUIRY_CMD 0x12
> #define INQUIRY_CMDLEN 6
> #define HEAVY_CHECK_COUNT 10
> +#define SCSI_COMMAND_TERMINATED 0x22
> +#define SCSI_CHECK_CONDITION 0x2
> +#define RECOVERED_ERROR 0x01
> +#define ILLEGAL_REQUEST 0x05
> +#define SG_ERR_DRIVER_SENSE 0x08
>
> /*
> * Mechanism to track CLARiiON inactive snapshot LUs.
> @@ -130,7 +135,9 @@ int libcheck_check (struct checker * c)
> (struct emc_clariion_checker_path_context *)c->context;
> char wwnstr[33];
> int ret;
> + int retry_emc = 5;
>
> +retry:
> memset(&io_hdr, 0, sizeof (struct sg_io_hdr));
> memset(sense_buffer, 0, 128);
> memset(sb, 0, SENSE_BUFF_LEN);
> @@ -145,12 +152,51 @@ int libcheck_check (struct checker * c)
> io_hdr.timeout = c->timeout * 1000;
> io_hdr.pack_id = 0;
> if (ioctl(c->fd, SG_IO, &io_hdr) < 0) {
> + if (errno == ENOTTY) {
> + c->msgid = CHECKER_MSGID_UNSUPPORTED;
> + return PATH_WILD;
> + }
> c->msgid = MSG_CLARIION_QUERY_FAILED;
> return PATH_DOWN;
> }
> +
> if (io_hdr.info & SG_INFO_OK_MASK) {
> - c->msgid = MSG_CLARIION_QUERY_ERROR;
> - return PATH_DOWN;
Previously, if (io_hdr.info & SG_INFO_OK_MASK) the checker would always
return PATH_DOWN. Both the tur and rdac checker always return either
PATH_DOWN or PATH_WILD if (io_hdr.info & SG_INFO_OK_MASK && sense_key
!= RECOVERED_ERROR). With the clariion checker, it now appears possible
to have (io_hdr.info & SG_INFO_OK_MASK && sense_key != RECOVERED_ERROR)
and still return PATH_UP. Is this intentional? Am I missing something
here?
> + switch (io_hdr.host_status) {
> + case DID_BUS_BUSY:
> + case DID_ERROR:
> + case DID_SOFT_ERROR:
> + case DID_TRANSPORT_DISRUPTED:
> + /* Transport error, retry */
> + if (--retry_emc)
> + 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)) {
> + if (io_hdr.sbp && (io_hdr.sb_len_wr > 2)) {
> + unsigned char *sbp = io_hdr.sbp;
> + int sense_key;
> +
> + if (sbp[0] & 0x2)
> + sense_key = sbp[1] & 0xf;
> + else
> + sense_key = sbp[2] & 0xf;
> +
> + if (sense_key == ILLEGAL_REQUEST) {
> + c->msgid = CHECKER_MSGID_UNSUPPORTED;
> + return PATH_WILD;
> + } else if (sense_key != RECOVERED_ERROR) {
> + condlog(1, "emc_clariion_checker: INQUIRY failed with sense key %02x",
> + sense_key);
> + c->msgid = MSG_CLARIION_QUERY_ERROR;
> + return PATH_DOWN;
> + }
> + }
> }
> if (/* Verify the code page - right page & revision */
> sense_buffer[1] != 0xc0 || sense_buffer[9] != 0x00) {
> --
> 2.19.0
--
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