From 8e67ce6072a0ab7fcefbbd2913fa4eaf3fdd8d68 Mon Sep 17 00:00:00 2001 From: Rob Evers Date: Fri, 18 May 2012 14:08:55 -0400 Subject: [PATCH] [SCSI] scsi_dh_alua: retry alua rtpg extended header for illegal request response 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 Reviewed-by: Babu Moger Signed-off-by: James Bottomley --- drivers/scsi/device_handler/scsi_dh_alua.c | 26 +++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index ac6fddf99e99..5a3448856962 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -178,7 +178,8 @@ 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; @@ -189,7 +190,10 @@ 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; @@ -522,6 +526,7 @@ 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; @@ -532,7 +537,7 @@ 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, @@ -540,6 +545,21 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) if (!err) return SCSI_DH_IO; + /* + * submit_rtpg() has failed on existing arrays + * when requesting extended header info, and + * the array doesn't support extended headers, + * even though it shouldn't according to T10. + * The retry without rtpg_ext_hdr_req set + * handles this. + */ + if (rtpg_ext_hdr_req == 1 && + sense_hdr.sense_key == ILLEGAL_REQUEST && + sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) { + rtpg_ext_hdr_req = 0; + goto retry; + } + err = alua_check_sense(sdev, &sense_hdr); if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry)) goto retry;