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![Mike Christie](/assets/img/avatar_default.png)
We do not need to set REQ_NOMERGE because when the module calls blk_execute_rq -> blk_execute_rq_nowait, blk_execute_rq_nowait sets it for us. This brings all the modules in sync for those bits. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
803 lines
19 KiB
C
803 lines
19 KiB
C
/*
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* Generic SCSI-3 ALUA SCSI Device Handler
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*
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* Copyright (C) 2007, 2008 Hannes Reinecke, SUSE Linux Products GmbH.
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#include <scsi/scsi.h>
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#include <scsi/scsi_eh.h>
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#include <scsi/scsi_dh.h>
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#define ALUA_DH_NAME "alua"
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#define ALUA_DH_VER "1.2"
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#define TPGS_STATE_OPTIMIZED 0x0
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#define TPGS_STATE_NONOPTIMIZED 0x1
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#define TPGS_STATE_STANDBY 0x2
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#define TPGS_STATE_UNAVAILABLE 0x3
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#define TPGS_STATE_OFFLINE 0xe
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#define TPGS_STATE_TRANSITIONING 0xf
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#define TPGS_SUPPORT_NONE 0x00
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#define TPGS_SUPPORT_OPTIMIZED 0x01
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#define TPGS_SUPPORT_NONOPTIMIZED 0x02
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#define TPGS_SUPPORT_STANDBY 0x04
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#define TPGS_SUPPORT_UNAVAILABLE 0x08
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#define TPGS_SUPPORT_OFFLINE 0x40
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#define TPGS_SUPPORT_TRANSITION 0x80
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#define TPGS_MODE_UNINITIALIZED -1
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#define TPGS_MODE_NONE 0x0
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#define TPGS_MODE_IMPLICIT 0x1
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#define TPGS_MODE_EXPLICIT 0x2
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#define ALUA_INQUIRY_SIZE 36
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#define ALUA_FAILOVER_TIMEOUT (60 * HZ)
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#define ALUA_FAILOVER_RETRIES 5
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struct alua_dh_data {
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int group_id;
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int rel_port;
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int tpgs;
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int state;
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unsigned char inq[ALUA_INQUIRY_SIZE];
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unsigned char *buff;
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int bufflen;
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unsigned char sense[SCSI_SENSE_BUFFERSIZE];
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int senselen;
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};
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#define ALUA_POLICY_SWITCH_CURRENT 0
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#define ALUA_POLICY_SWITCH_ALL 1
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static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev)
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{
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struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
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BUG_ON(scsi_dh_data == NULL);
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return ((struct alua_dh_data *) scsi_dh_data->buf);
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}
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static int realloc_buffer(struct alua_dh_data *h, unsigned len)
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{
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if (h->buff && h->buff != h->inq)
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kfree(h->buff);
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h->buff = kmalloc(len, GFP_NOIO);
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if (!h->buff) {
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h->buff = h->inq;
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h->bufflen = ALUA_INQUIRY_SIZE;
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return 1;
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}
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h->bufflen = len;
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return 0;
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}
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static struct request *get_alua_req(struct scsi_device *sdev,
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void *buffer, unsigned buflen, int rw)
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{
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struct request *rq;
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struct request_queue *q = sdev->request_queue;
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rq = blk_get_request(q, rw, GFP_NOIO);
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if (!rq) {
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sdev_printk(KERN_INFO, sdev,
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"%s: blk_get_request failed\n", __func__);
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return NULL;
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}
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if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
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blk_put_request(rq);
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sdev_printk(KERN_INFO, sdev,
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"%s: blk_rq_map_kern failed\n", __func__);
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return NULL;
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}
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rq->cmd_type = REQ_TYPE_BLOCK_PC;
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rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
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REQ_FAILFAST_DRIVER;
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rq->retries = ALUA_FAILOVER_RETRIES;
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rq->timeout = ALUA_FAILOVER_TIMEOUT;
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return rq;
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}
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/*
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* submit_std_inquiry - Issue a standard INQUIRY command
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* @sdev: sdev the command should be send to
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*/
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static int submit_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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struct request *rq;
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int err = SCSI_DH_RES_TEMP_UNAVAIL;
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rq = get_alua_req(sdev, h->inq, ALUA_INQUIRY_SIZE, READ);
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if (!rq)
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goto done;
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/* Prepare the command. */
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rq->cmd[0] = INQUIRY;
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rq->cmd[1] = 0;
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rq->cmd[2] = 0;
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rq->cmd[4] = ALUA_INQUIRY_SIZE;
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rq->cmd_len = COMMAND_SIZE(INQUIRY);
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rq->sense = h->sense;
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memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
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rq->sense_len = h->senselen = 0;
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err = blk_execute_rq(rq->q, NULL, rq, 1);
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if (err == -EIO) {
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sdev_printk(KERN_INFO, sdev,
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"%s: std inquiry failed with %x\n",
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ALUA_DH_NAME, rq->errors);
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h->senselen = rq->sense_len;
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err = SCSI_DH_IO;
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}
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blk_put_request(rq);
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done:
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return err;
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}
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/*
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* submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command
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* @sdev: sdev the command should be sent to
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*/
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static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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struct request *rq;
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int err = SCSI_DH_RES_TEMP_UNAVAIL;
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rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
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if (!rq)
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goto done;
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/* Prepare the command. */
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rq->cmd[0] = INQUIRY;
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rq->cmd[1] = 1;
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rq->cmd[2] = 0x83;
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rq->cmd[4] = h->bufflen;
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rq->cmd_len = COMMAND_SIZE(INQUIRY);
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rq->sense = h->sense;
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memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
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rq->sense_len = h->senselen = 0;
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err = blk_execute_rq(rq->q, NULL, rq, 1);
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if (err == -EIO) {
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sdev_printk(KERN_INFO, sdev,
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"%s: evpd inquiry failed with %x\n",
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ALUA_DH_NAME, rq->errors);
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h->senselen = rq->sense_len;
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err = SCSI_DH_IO;
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}
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blk_put_request(rq);
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done:
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return err;
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}
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/*
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* submit_rtpg - Issue a REPORT TARGET GROUP STATES command
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* @sdev: sdev the command should be sent to
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*/
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static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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struct request *rq;
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int err = SCSI_DH_RES_TEMP_UNAVAIL;
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rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
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if (!rq)
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goto done;
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/* Prepare the command. */
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rq->cmd[0] = MAINTENANCE_IN;
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rq->cmd[1] = MI_REPORT_TARGET_PGS;
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rq->cmd[6] = (h->bufflen >> 24) & 0xff;
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rq->cmd[7] = (h->bufflen >> 16) & 0xff;
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rq->cmd[8] = (h->bufflen >> 8) & 0xff;
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rq->cmd[9] = h->bufflen & 0xff;
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rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN);
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rq->sense = h->sense;
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memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
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rq->sense_len = h->senselen = 0;
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err = blk_execute_rq(rq->q, NULL, rq, 1);
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if (err == -EIO) {
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sdev_printk(KERN_INFO, sdev,
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"%s: rtpg failed with %x\n",
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ALUA_DH_NAME, rq->errors);
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h->senselen = rq->sense_len;
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err = SCSI_DH_IO;
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}
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blk_put_request(rq);
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done:
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return err;
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}
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/*
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* submit_stpg - Issue a SET TARGET GROUP STATES command
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* @sdev: sdev the command should be sent to
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*
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* Currently we're only setting the current target port group state
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* to 'active/optimized' and let the array firmware figure out
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* the states of the remaining groups.
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*/
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static unsigned submit_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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struct request *rq;
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int err = SCSI_DH_RES_TEMP_UNAVAIL;
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int stpg_len = 8;
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/* Prepare the data buffer */
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memset(h->buff, 0, stpg_len);
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h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f;
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h->buff[6] = (h->group_id >> 8) & 0x0f;
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h->buff[7] = h->group_id & 0x0f;
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rq = get_alua_req(sdev, h->buff, stpg_len, WRITE);
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if (!rq)
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goto done;
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/* Prepare the command. */
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rq->cmd[0] = MAINTENANCE_OUT;
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rq->cmd[1] = MO_SET_TARGET_PGS;
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rq->cmd[6] = (stpg_len >> 24) & 0xff;
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rq->cmd[7] = (stpg_len >> 16) & 0xff;
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rq->cmd[8] = (stpg_len >> 8) & 0xff;
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rq->cmd[9] = stpg_len & 0xff;
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rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT);
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rq->sense = h->sense;
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memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
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rq->sense_len = h->senselen = 0;
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err = blk_execute_rq(rq->q, NULL, rq, 1);
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if (err == -EIO) {
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sdev_printk(KERN_INFO, sdev,
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"%s: stpg failed with %x\n",
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ALUA_DH_NAME, rq->errors);
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h->senselen = rq->sense_len;
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err = SCSI_DH_IO;
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}
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blk_put_request(rq);
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done:
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return err;
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}
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/*
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* alua_std_inquiry - Evaluate standard INQUIRY command
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* @sdev: device to be checked
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*
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* Just extract the TPGS setting to find out if ALUA
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* is supported.
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*/
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static int alua_std_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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int err;
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err = submit_std_inquiry(sdev, h);
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if (err != SCSI_DH_OK)
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return err;
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/* Check TPGS setting */
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h->tpgs = (h->inq[5] >> 4) & 0x3;
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switch (h->tpgs) {
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case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
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sdev_printk(KERN_INFO, sdev,
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"%s: supports implicit and explicit TPGS\n",
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ALUA_DH_NAME);
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break;
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case TPGS_MODE_EXPLICIT:
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sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n",
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ALUA_DH_NAME);
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break;
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case TPGS_MODE_IMPLICIT:
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sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n",
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ALUA_DH_NAME);
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break;
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default:
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h->tpgs = TPGS_MODE_NONE;
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sdev_printk(KERN_INFO, sdev, "%s: not supported\n",
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ALUA_DH_NAME);
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err = SCSI_DH_DEV_UNSUPP;
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break;
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}
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return err;
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}
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/*
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* alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83
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* @sdev: device to be checked
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*
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* Extract the relative target port and the target port group
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* descriptor from the list of identificators.
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*/
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static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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int len;
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unsigned err;
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unsigned char *d;
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retry:
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err = submit_vpd_inquiry(sdev, h);
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if (err != SCSI_DH_OK)
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return err;
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/* Check if vpd page exceeds initial buffer */
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len = (h->buff[2] << 8) + h->buff[3] + 4;
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if (len > h->bufflen) {
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/* Resubmit with the correct length */
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if (realloc_buffer(h, len)) {
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sdev_printk(KERN_WARNING, sdev,
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"%s: kmalloc buffer failed\n",
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ALUA_DH_NAME);
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/* Temporary failure, bypass */
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return SCSI_DH_DEV_TEMP_BUSY;
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}
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goto retry;
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}
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/*
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* Now look for the correct descriptor.
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*/
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d = h->buff + 4;
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while (d < h->buff + len) {
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switch (d[1] & 0xf) {
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case 0x4:
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/* Relative target port */
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h->rel_port = (d[6] << 8) + d[7];
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break;
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case 0x5:
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/* Target port group */
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h->group_id = (d[6] << 8) + d[7];
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break;
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default:
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break;
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}
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d += d[3] + 4;
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}
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if (h->group_id == -1) {
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/*
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* Internal error; TPGS supported but required
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* VPD identification descriptors not present.
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* Disable ALUA support
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*/
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sdev_printk(KERN_INFO, sdev,
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"%s: No target port descriptors found\n",
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ALUA_DH_NAME);
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h->state = TPGS_STATE_OPTIMIZED;
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h->tpgs = TPGS_MODE_NONE;
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err = SCSI_DH_DEV_UNSUPP;
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} else {
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sdev_printk(KERN_INFO, sdev,
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"%s: port group %02x rel port %02x\n",
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ALUA_DH_NAME, h->group_id, h->rel_port);
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}
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return err;
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}
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static char print_alua_state(int state)
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{
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switch (state) {
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case TPGS_STATE_OPTIMIZED:
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return 'A';
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case TPGS_STATE_NONOPTIMIZED:
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return 'N';
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case TPGS_STATE_STANDBY:
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return 'S';
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case TPGS_STATE_UNAVAILABLE:
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return 'U';
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case TPGS_STATE_OFFLINE:
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return 'O';
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case TPGS_STATE_TRANSITIONING:
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return 'T';
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default:
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return 'X';
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}
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}
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static int alua_check_sense(struct scsi_device *sdev,
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struct scsi_sense_hdr *sense_hdr)
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{
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switch (sense_hdr->sense_key) {
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case NOT_READY:
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if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a)
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/*
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* LUN Not Accessible - ALUA state transition
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*/
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return ADD_TO_MLQUEUE;
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if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b)
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/*
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* LUN Not Accessible -- Target port in standby state
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*/
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return SUCCESS;
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if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c)
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/*
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* LUN Not Accessible -- Target port in unavailable state
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*/
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return SUCCESS;
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if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12)
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/*
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* LUN Not Ready -- Offline
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*/
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return SUCCESS;
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break;
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case UNIT_ATTENTION:
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if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
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/*
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* Power On, Reset, or Bus Device Reset, just retry.
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*/
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return ADD_TO_MLQUEUE;
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if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
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/*
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* ALUA state changed
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*/
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return ADD_TO_MLQUEUE;
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}
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if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
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/*
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* Implicit ALUA state transition failed
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*/
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return ADD_TO_MLQUEUE;
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}
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break;
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}
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return SCSI_RETURN_NOT_HANDLED;
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}
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/*
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* alua_stpg - Evaluate SET TARGET GROUP STATES
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* @sdev: the device to be evaluated
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* @state: the new target group state
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*
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* Send a SET TARGET GROUP STATES command to the device.
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* We only have to test here if we should resubmit the command;
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* any other error is assumed as a failure.
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*/
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static int alua_stpg(struct scsi_device *sdev, int state,
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struct alua_dh_data *h)
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{
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struct scsi_sense_hdr sense_hdr;
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unsigned err;
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int retry = ALUA_FAILOVER_RETRIES;
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retry:
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err = submit_stpg(sdev, h);
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if (err == SCSI_DH_IO && h->senselen > 0) {
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err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
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&sense_hdr);
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|
if (!err)
|
|
return SCSI_DH_IO;
|
|
err = alua_check_sense(sdev, &sense_hdr);
|
|
if (retry > 0 && err == ADD_TO_MLQUEUE) {
|
|
retry--;
|
|
goto retry;
|
|
}
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: stpg sense code: %02x/%02x/%02x\n",
|
|
ALUA_DH_NAME, sense_hdr.sense_key,
|
|
sense_hdr.asc, sense_hdr.ascq);
|
|
err = SCSI_DH_IO;
|
|
}
|
|
if (err == SCSI_DH_OK) {
|
|
h->state = state;
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: port group %02x switched to state %c\n",
|
|
ALUA_DH_NAME, h->group_id,
|
|
print_alua_state(h->state) );
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* alua_rtpg - Evaluate REPORT TARGET GROUP STATES
|
|
* @sdev: the device to be evaluated.
|
|
*
|
|
* Evaluate the Target Port Group State.
|
|
* Returns SCSI_DH_DEV_OFFLINED if the path is
|
|
* found to be unuseable.
|
|
*/
|
|
static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
|
|
{
|
|
struct scsi_sense_hdr sense_hdr;
|
|
int len, k, off, valid_states = 0;
|
|
char *ucp;
|
|
unsigned err;
|
|
|
|
retry:
|
|
err = submit_rtpg(sdev, h);
|
|
|
|
if (err == SCSI_DH_IO && h->senselen > 0) {
|
|
err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
|
|
&sense_hdr);
|
|
if (!err)
|
|
return SCSI_DH_IO;
|
|
|
|
err = alua_check_sense(sdev, &sense_hdr);
|
|
if (err == ADD_TO_MLQUEUE)
|
|
goto retry;
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: rtpg sense code %02x/%02x/%02x\n",
|
|
ALUA_DH_NAME, sense_hdr.sense_key,
|
|
sense_hdr.asc, sense_hdr.ascq);
|
|
err = SCSI_DH_IO;
|
|
}
|
|
if (err != SCSI_DH_OK)
|
|
return err;
|
|
|
|
len = (h->buff[0] << 24) + (h->buff[1] << 16) +
|
|
(h->buff[2] << 8) + h->buff[3] + 4;
|
|
|
|
if (len > h->bufflen) {
|
|
/* Resubmit with the correct length */
|
|
if (realloc_buffer(h, len)) {
|
|
sdev_printk(KERN_WARNING, sdev,
|
|
"%s: kmalloc buffer failed\n",__func__);
|
|
/* Temporary failure, bypass */
|
|
return SCSI_DH_DEV_TEMP_BUSY;
|
|
}
|
|
goto retry;
|
|
}
|
|
|
|
for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
|
|
if (h->group_id == (ucp[2] << 8) + ucp[3]) {
|
|
h->state = ucp[0] & 0x0f;
|
|
valid_states = ucp[1];
|
|
}
|
|
off = 8 + (ucp[7] * 4);
|
|
}
|
|
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: port group %02x state %c supports %c%c%c%c%c%c\n",
|
|
ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
|
|
valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
|
|
valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
|
|
valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
|
|
valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
|
|
valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
|
|
valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
|
|
|
|
if (h->tpgs & TPGS_MODE_EXPLICIT) {
|
|
switch (h->state) {
|
|
case TPGS_STATE_TRANSITIONING:
|
|
/* State transition, retry */
|
|
goto retry;
|
|
break;
|
|
case TPGS_STATE_OFFLINE:
|
|
/* Path is offline, fail */
|
|
err = SCSI_DH_DEV_OFFLINED;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
} else {
|
|
/* Only Implicit ALUA support */
|
|
if (h->state == TPGS_STATE_OPTIMIZED ||
|
|
h->state == TPGS_STATE_NONOPTIMIZED ||
|
|
h->state == TPGS_STATE_STANDBY)
|
|
/* Useable path if active */
|
|
err = SCSI_DH_OK;
|
|
else
|
|
/* Path unuseable for unavailable/offline */
|
|
err = SCSI_DH_DEV_OFFLINED;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* alua_initialize - Initialize ALUA state
|
|
* @sdev: the device to be initialized
|
|
*
|
|
* For the prep_fn to work correctly we have
|
|
* to initialize the ALUA state for the device.
|
|
*/
|
|
static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
|
|
{
|
|
int err;
|
|
|
|
err = alua_std_inquiry(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
err = alua_vpd_inquiry(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
err = alua_rtpg(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* alua_activate - activate a path
|
|
* @sdev: device on the path to be activated
|
|
*
|
|
* We're currently switching the port group to be activated only and
|
|
* let the array figure out the rest.
|
|
* There may be other arrays which require us to switch all port groups
|
|
* based on a certain policy. But until we actually encounter them it
|
|
* should be okay.
|
|
*/
|
|
static int alua_activate(struct scsi_device *sdev)
|
|
{
|
|
struct alua_dh_data *h = get_alua_data(sdev);
|
|
int err = SCSI_DH_OK;
|
|
|
|
if (h->group_id != -1) {
|
|
err = alua_rtpg(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
}
|
|
|
|
if (h->tpgs == TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED)
|
|
err = alua_stpg(sdev, TPGS_STATE_OPTIMIZED, h);
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* alua_prep_fn - request callback
|
|
*
|
|
* Fail I/O to all paths not in state
|
|
* active/optimized or active/non-optimized.
|
|
*/
|
|
static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct alua_dh_data *h = get_alua_data(sdev);
|
|
int ret = BLKPREP_OK;
|
|
|
|
if (h->state != TPGS_STATE_OPTIMIZED &&
|
|
h->state != TPGS_STATE_NONOPTIMIZED) {
|
|
ret = BLKPREP_KILL;
|
|
req->cmd_flags |= REQ_QUIET;
|
|
}
|
|
return ret;
|
|
|
|
}
|
|
|
|
static const struct scsi_dh_devlist alua_dev_list[] = {
|
|
{"HP", "MSA VOLUME" },
|
|
{"HP", "HSV101" },
|
|
{"HP", "HSV111" },
|
|
{"HP", "HSV200" },
|
|
{"HP", "HSV210" },
|
|
{"HP", "HSV300" },
|
|
{"IBM", "2107900" },
|
|
{"IBM", "2145" },
|
|
{"Pillar", "Axiom" },
|
|
{NULL, NULL}
|
|
};
|
|
|
|
static int alua_bus_attach(struct scsi_device *sdev);
|
|
static void alua_bus_detach(struct scsi_device *sdev);
|
|
|
|
static struct scsi_device_handler alua_dh = {
|
|
.name = ALUA_DH_NAME,
|
|
.module = THIS_MODULE,
|
|
.devlist = alua_dev_list,
|
|
.attach = alua_bus_attach,
|
|
.detach = alua_bus_detach,
|
|
.prep_fn = alua_prep_fn,
|
|
.check_sense = alua_check_sense,
|
|
.activate = alua_activate,
|
|
};
|
|
|
|
/*
|
|
* alua_bus_attach - Attach device handler
|
|
* @sdev: device to be attached to
|
|
*/
|
|
static int alua_bus_attach(struct scsi_device *sdev)
|
|
{
|
|
struct scsi_dh_data *scsi_dh_data;
|
|
struct alua_dh_data *h;
|
|
unsigned long flags;
|
|
int err = SCSI_DH_OK;
|
|
|
|
scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
|
|
+ sizeof(*h) , GFP_KERNEL);
|
|
if (!scsi_dh_data) {
|
|
sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
|
|
ALUA_DH_NAME);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
scsi_dh_data->scsi_dh = &alua_dh;
|
|
h = (struct alua_dh_data *) scsi_dh_data->buf;
|
|
h->tpgs = TPGS_MODE_UNINITIALIZED;
|
|
h->state = TPGS_STATE_OPTIMIZED;
|
|
h->group_id = -1;
|
|
h->rel_port = -1;
|
|
h->buff = h->inq;
|
|
h->bufflen = ALUA_INQUIRY_SIZE;
|
|
|
|
err = alua_initialize(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto failed;
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
|
goto failed;
|
|
|
|
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
|
|
sdev->scsi_dh_data = scsi_dh_data;
|
|
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
|
|
|
|
return 0;
|
|
|
|
failed:
|
|
kfree(scsi_dh_data);
|
|
sdev_printk(KERN_ERR, sdev, "%s: not attached\n", ALUA_DH_NAME);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* alua_bus_detach - Detach device handler
|
|
* @sdev: device to be detached from
|
|
*/
|
|
static void alua_bus_detach(struct scsi_device *sdev)
|
|
{
|
|
struct scsi_dh_data *scsi_dh_data;
|
|
struct alua_dh_data *h;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
|
|
scsi_dh_data = sdev->scsi_dh_data;
|
|
sdev->scsi_dh_data = NULL;
|
|
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
|
|
|
|
h = (struct alua_dh_data *) scsi_dh_data->buf;
|
|
if (h->buff && h->inq != h->buff)
|
|
kfree(h->buff);
|
|
kfree(scsi_dh_data);
|
|
module_put(THIS_MODULE);
|
|
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", ALUA_DH_NAME);
|
|
}
|
|
|
|
static int __init alua_init(void)
|
|
{
|
|
int r;
|
|
|
|
r = scsi_register_device_handler(&alua_dh);
|
|
if (r != 0)
|
|
printk(KERN_ERR "%s: Failed to register scsi device handler",
|
|
ALUA_DH_NAME);
|
|
return r;
|
|
}
|
|
|
|
static void __exit alua_exit(void)
|
|
{
|
|
scsi_unregister_device_handler(&alua_dh);
|
|
}
|
|
|
|
module_init(alua_init);
|
|
module_exit(alua_exit);
|
|
|
|
MODULE_DESCRIPTION("DM Multipath ALUA support");
|
|
MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(ALUA_DH_VER);
|