Rob, Minor comments below. > -----Original Message----- > From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Rob Evers > Sent: Wednesday, May 16, 2012 9:15 AM > To: linux-scsi@xxxxxxxxxxxxxxx > Subject: [PATCH 2/3] alua: retry alua rtpg extended header for illegal request > response > > From: Rob Evers <revers@xxxxxxxxxx> > > Some storage arrays are known to return 'illegal request' > when an rtpg extended header request is made. T10 says the > array should ignore the bit, and return the non-extended > rtpg as the array doesn't support the request. Working > around this by retrying the rtpg request without the extended > header bit set when the extended rtpg request results in > illegal request. > > Signed-off-by: Rob Evers <revers@xxxxxxxxxx> > --- > drivers/scsi/device_handler/scsi_dh_alua.c | 25 > ++++++++++++++++++++++--- > 1 files changed, 22 insertions(+), 3 deletions(-) > > diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c > b/drivers/scsi/device_handler/scsi_dh_alua.c > index 6a7efd3..ca414ae 100644 > --- a/drivers/scsi/device_handler/scsi_dh_alua.c > +++ b/drivers/scsi/device_handler/scsi_dh_alua.c > @@ -173,7 +173,8 @@ done: > * submit_rtpg - Issue a REPORT TARGET GROUP STATES command > * @sdev: sdev the command should be sent to > */ > -static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data > *h) > +static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data > *h, > + bool rtpg_ext_hdr_req) > { > struct request *rq; > int err = SCSI_DH_RES_TEMP_UNAVAIL; > @@ -184,7 +185,10 @@ static unsigned submit_rtpg(struct scsi_device > *sdev, struct alua_dh_data *h) > > /* Prepare the command. */ > rq->cmd[0] = MAINTENANCE_IN; > - rq->cmd[1] = MI_REPORT_TARGET_PGS | > MI_EXT_HDR_PARAM_FMT; > + if (rtpg_ext_hdr_req) > + rq->cmd[1] = MI_REPORT_TARGET_PGS | > MI_EXT_HDR_PARAM_FMT; > + else > + rq->cmd[1] = MI_REPORT_TARGET_PGS; > rq->cmd[6] = (h->bufflen >> 24) & 0xff; > rq->cmd[7] = (h->bufflen >> 16) & 0xff; > rq->cmd[8] = (h->bufflen >> 8) & 0xff; > @@ -517,6 +521,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct > alua_dh_data *h) > int len, k, off, valid_states = 0; > unsigned char *ucp; > unsigned err; > + bool rtpg_ext_hdr_req = 1; > unsigned long expiry, interval = 1000; > unsigned int tpg_desc_tbl_off; > unsigned char orig_transition_tmo; > @@ -527,7 +532,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct > alua_dh_data *h) > expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); > > retry: > - err = submit_rtpg(sdev, h); > + err = submit_rtpg(sdev, h, rtpg_ext_hdr_req); > > if (err == SCSI_DH_IO && h->senselen > 0) { > err = scsi_normalize_sense(h->sense, > SCSI_SENSE_BUFFERSIZE, > @@ -535,6 +540,20 @@ static int alua_rtpg(struct scsi_device *sdev, struct > alua_dh_data *h) > if (!err) > return SCSI_DH_IO; > > + /* > + * submit_rtpb() has failed on existing arrays There is a typo. Should be submit_rtpg. > + * when requesting extended header info, and > + * the array doesn't support extended headers, > + * even though it shouldn't according to T10. > + * The retry without the ALUA_RTPG_EXT_HDR_REQ > + * handles this. > + */ > + if (sense_hdr.sense_key == ILLEGAL_REQUEST && > + sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { > + rtpg_ext_hdr_req = 0; > + goto retry; We should probably have an exit criteria here. What if target misbehaves (with ILLEGAL_REQUEST) even with rtpg_ext_hdr_req = 0. > + } > + > err = alua_check_sense(sdev, &sense_hdr); > if (err == ADD_TO_MLQUEUE && time_before(jiffies, > expiry)) > goto retry; > -- > 1.7.7.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
