808 lines
20 KiB
C
808 lines
20 KiB
C
/*
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* Generic SCSI-3 ALUA SCSI Device Handler
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*
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* Copyright (C) 2007-2010 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 <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <asm/unaligned.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_dbg.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 "1.3"
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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_LBA_DEPENDENT 0x4
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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_LBA_DEPENDENT 0x10
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#define TPGS_SUPPORT_OFFLINE 0x40
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#define TPGS_SUPPORT_TRANSITION 0x80
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#define RTPG_FMT_MASK 0x70
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#define RTPG_FMT_EXT_HDR 0x10
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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
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#define ALUA_FAILOVER_RETRIES 5
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/* device handler flags */
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#define ALUA_OPTIMIZE_STPG 1
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#define ALUA_RTPG_EXT_HDR_UNSUPP 2
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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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int pref;
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unsigned flags; /* used for optimizing STPG */
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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 transition_tmo;
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unsigned char sense[SCSI_SENSE_BUFFERSIZE];
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struct scsi_device *sdev;
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activate_complete callback_fn;
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void *callback_data;
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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 char print_alua_state(int);
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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 (IS_ERR(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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blk_rq_set_block_pc(rq);
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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_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 * HZ;
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return rq;
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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, unsigned char *buff,
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int bufflen, unsigned char *sense, int flags)
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{
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struct request *rq;
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int err = 0;
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rq = get_alua_req(sdev, buff, bufflen, READ);
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if (!rq) {
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err = DRIVER_BUSY << 24;
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goto done;
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}
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/* Prepare the command. */
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rq->cmd[0] = MAINTENANCE_IN;
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if (!(flags & ALUA_RTPG_EXT_HDR_UNSUPP))
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rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
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else
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rq->cmd[1] = MI_REPORT_TARGET_PGS;
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put_unaligned_be32(bufflen, &rq->cmd[6]);
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rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN);
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rq->sense = sense;
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memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
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rq->sense_len = 0;
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blk_execute_rq(rq->q, NULL, rq, 1);
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if (rq->errors)
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err = rq->errors;
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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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* stpg_endio - 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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* Evaluate a SET TARGET GROUP STATES command response.
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*/
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static void stpg_endio(struct request *req, int error)
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{
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struct alua_dh_data *h = req->end_io_data;
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struct scsi_sense_hdr sense_hdr;
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unsigned err = SCSI_DH_OK;
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if (host_byte(req->errors) != DID_OK ||
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msg_byte(req->errors) != COMMAND_COMPLETE) {
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err = SCSI_DH_IO;
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goto done;
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}
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if (scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
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&sense_hdr)) {
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if (sense_hdr.sense_key == NOT_READY &&
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sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) {
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/* ALUA state transition already in progress */
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err = SCSI_DH_OK;
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goto done;
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}
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if (sense_hdr.sense_key == UNIT_ATTENTION) {
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err = SCSI_DH_RETRY;
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goto done;
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}
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sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n",
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ALUA_DH_NAME);
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scsi_print_sense_hdr(h->sdev, ALUA_DH_NAME, &sense_hdr);
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err = SCSI_DH_IO;
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} else if (error)
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err = SCSI_DH_IO;
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if (err == SCSI_DH_OK) {
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h->state = TPGS_STATE_OPTIMIZED;
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sdev_printk(KERN_INFO, h->sdev,
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"%s: port group %02x switched to state %c\n",
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ALUA_DH_NAME, h->group_id,
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print_alua_state(h->state));
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}
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done:
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req->end_io_data = NULL;
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__blk_put_request(req->q, req);
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if (h->callback_fn) {
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h->callback_fn(h->callback_data, err);
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h->callback_fn = h->callback_data = NULL;
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}
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return;
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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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*
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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 alua_dh_data *h)
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{
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struct request *rq;
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int stpg_len = 8;
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struct scsi_device *sdev = h->sdev;
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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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put_unaligned_be16(h->group_id, &h->buff[6]);
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rq = get_alua_req(sdev, h->buff, stpg_len, WRITE);
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if (!rq)
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return SCSI_DH_RES_TEMP_UNAVAIL;
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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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put_unaligned_be32(stpg_len, &rq->cmd[6]);
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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 = 0;
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rq->end_io_data = h;
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blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio);
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return SCSI_DH_OK;
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}
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/*
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* alua_check_tpgs - Evaluate TPGS setting
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* @sdev: device to be checked
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*
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* Examine the TPGS setting of the sdev to find out if ALUA
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* is supported.
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*/
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static int alua_check_tpgs(struct scsi_device *sdev)
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{
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int tpgs = TPGS_MODE_NONE;
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/*
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* ALUA support for non-disk devices is fraught with
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* difficulties, so disable it for now.
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*/
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if (sdev->type != TYPE_DISK) {
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sdev_printk(KERN_INFO, sdev,
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"%s: disable for non-disk devices\n",
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ALUA_DH_NAME);
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return tpgs;
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}
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tpgs = scsi_device_tpgs(sdev);
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switch (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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case 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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break;
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default:
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sdev_printk(KERN_INFO, sdev,
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"%s: unsupported TPGS setting %d\n",
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ALUA_DH_NAME, tpgs);
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tpgs = TPGS_MODE_NONE;
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break;
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}
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return tpgs;
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}
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/*
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* alua_check_vpd - 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_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
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{
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int rel_port = -1, group_id;
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group_id = scsi_vpd_tpg_id(sdev, &rel_port);
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if (group_id < 0) {
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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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return SCSI_DH_DEV_UNSUPP;
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}
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h->state = TPGS_STATE_OPTIMIZED;
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h->group_id = group_id;
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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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return 0;
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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_LBA_DEPENDENT:
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return 'L';
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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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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 == 0x29 && sense_hdr->ascq == 0x04)
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/*
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* Device internal reset
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*/
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return ADD_TO_MLQUEUE;
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if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01)
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/*
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* Mode Parameters Changed
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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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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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if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03)
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/*
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* Inquiry data has changed
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*/
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return ADD_TO_MLQUEUE;
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if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e)
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/*
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* REPORTED_LUNS_DATA_HAS_CHANGED is reported
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* when switching controllers on targets like
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* Intel Multi-Flex. We can just retry.
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*/
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return ADD_TO_MLQUEUE;
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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_rtpg - Evaluate REPORT TARGET GROUP STATES
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* @sdev: the device to be evaluated.
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* @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state
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*
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* Evaluate the Target Port Group State.
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* Returns SCSI_DH_DEV_OFFLINED if the path is
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* found to be unusable.
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*/
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static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition)
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{
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struct scsi_sense_hdr sense_hdr;
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int len, k, off, valid_states = 0;
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unsigned char *ucp;
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unsigned err, retval;
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unsigned long expiry, interval = 0;
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unsigned int tpg_desc_tbl_off;
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unsigned char orig_transition_tmo;
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if (!h->transition_tmo)
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expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ);
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else
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expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ);
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retry:
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retval = submit_rtpg(sdev, h->buff, h->bufflen, h->sense, h->flags);
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if (retval) {
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if (!scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
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&sense_hdr)) {
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sdev_printk(KERN_INFO, sdev,
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"%s: rtpg failed, result %d\n",
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ALUA_DH_NAME, retval);
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if (driver_byte(retval) == DRIVER_BUSY)
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return SCSI_DH_DEV_TEMP_BUSY;
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return SCSI_DH_IO;
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}
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/*
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* submit_rtpg() has failed on existing arrays
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* when requesting extended header info, and
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* the array doesn't support extended headers,
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* even though it shouldn't according to T10.
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* The retry without rtpg_ext_hdr_req set
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* handles this.
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*/
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if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
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sense_hdr.sense_key == ILLEGAL_REQUEST &&
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sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
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h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
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goto retry;
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}
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/*
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* Retry on ALUA state transition or if any
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* UNIT ATTENTION occurred.
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*/
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if (sense_hdr.sense_key == NOT_READY &&
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sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
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err = SCSI_DH_RETRY;
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else if (sense_hdr.sense_key == UNIT_ATTENTION)
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err = SCSI_DH_RETRY;
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if (err == SCSI_DH_RETRY && time_before(jiffies, expiry)) {
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sdev_printk(KERN_ERR, sdev, "%s: rtpg retry\n",
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ALUA_DH_NAME);
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scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
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goto retry;
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}
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sdev_printk(KERN_ERR, sdev, "%s: rtpg failed\n",
|
|
ALUA_DH_NAME);
|
|
scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
|
|
return SCSI_DH_IO;
|
|
}
|
|
|
|
len = get_unaligned_be32(&h->buff[0]) + 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;
|
|
}
|
|
|
|
orig_transition_tmo = h->transition_tmo;
|
|
if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0)
|
|
h->transition_tmo = h->buff[5];
|
|
else
|
|
h->transition_tmo = ALUA_FAILOVER_TIMEOUT;
|
|
|
|
if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) {
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: transition timeout set to %d seconds\n",
|
|
ALUA_DH_NAME, h->transition_tmo);
|
|
expiry = jiffies + h->transition_tmo * HZ;
|
|
}
|
|
|
|
if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR)
|
|
tpg_desc_tbl_off = 8;
|
|
else
|
|
tpg_desc_tbl_off = 4;
|
|
|
|
for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off;
|
|
k < len;
|
|
k += off, ucp += off) {
|
|
|
|
if (h->group_id == get_unaligned_be16(&ucp[2])) {
|
|
h->state = ucp[0] & 0x0f;
|
|
h->pref = ucp[0] >> 7;
|
|
valid_states = ucp[1];
|
|
}
|
|
off = 8 + (ucp[7] * 4);
|
|
}
|
|
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n",
|
|
ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
|
|
h->pref ? "preferred" : "non-preferred",
|
|
valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
|
|
valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
|
|
valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
|
|
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');
|
|
|
|
switch (h->state) {
|
|
case TPGS_STATE_TRANSITIONING:
|
|
if (wait_for_transition) {
|
|
if (time_before(jiffies, expiry)) {
|
|
/* State transition, retry */
|
|
interval += 2000;
|
|
msleep(interval);
|
|
goto retry;
|
|
}
|
|
err = SCSI_DH_RETRY;
|
|
} else {
|
|
err = SCSI_DH_OK;
|
|
}
|
|
|
|
/* Transitioning time exceeded, set port to standby */
|
|
h->state = TPGS_STATE_STANDBY;
|
|
break;
|
|
case TPGS_STATE_OFFLINE:
|
|
/* Path unusable */
|
|
err = SCSI_DH_DEV_OFFLINED;
|
|
break;
|
|
default:
|
|
/* Useable path if active */
|
|
err = SCSI_DH_OK;
|
|
break;
|
|
}
|
|
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 = SCSI_DH_DEV_UNSUPP;
|
|
|
|
h->tpgs = alua_check_tpgs(sdev);
|
|
if (h->tpgs == TPGS_MODE_NONE)
|
|
goto out;
|
|
|
|
err = alua_check_vpd(sdev, h);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
err = alua_rtpg(sdev, h, 0);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
/*
|
|
* alua_set_params - set/unset the optimize flag
|
|
* @sdev: device on the path to be activated
|
|
* params - parameters in the following format
|
|
* "no_of_params\0param1\0param2\0param3\0...\0"
|
|
* For example, to set the flag pass the following parameters
|
|
* from multipath.conf
|
|
* hardware_handler "2 alua 1"
|
|
*/
|
|
static int alua_set_params(struct scsi_device *sdev, const char *params)
|
|
{
|
|
struct alua_dh_data *h = sdev->handler_data;
|
|
unsigned int optimize = 0, argc;
|
|
const char *p = params;
|
|
int result = SCSI_DH_OK;
|
|
|
|
if ((sscanf(params, "%u", &argc) != 1) || (argc != 1))
|
|
return -EINVAL;
|
|
|
|
while (*p++)
|
|
;
|
|
if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1))
|
|
return -EINVAL;
|
|
|
|
if (optimize)
|
|
h->flags |= ALUA_OPTIMIZE_STPG;
|
|
else
|
|
h->flags &= ~ALUA_OPTIMIZE_STPG;
|
|
|
|
return result;
|
|
}
|
|
|
|
static uint optimize_stpg;
|
|
module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR);
|
|
MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0.");
|
|
|
|
/*
|
|
* 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,
|
|
activate_complete fn, void *data)
|
|
{
|
|
struct alua_dh_data *h = sdev->handler_data;
|
|
int err = SCSI_DH_OK;
|
|
int stpg = 0;
|
|
|
|
err = alua_rtpg(sdev, h, 1);
|
|
if (err != SCSI_DH_OK)
|
|
goto out;
|
|
|
|
if (optimize_stpg)
|
|
h->flags |= ALUA_OPTIMIZE_STPG;
|
|
|
|
if (h->tpgs & TPGS_MODE_EXPLICIT) {
|
|
switch (h->state) {
|
|
case TPGS_STATE_NONOPTIMIZED:
|
|
stpg = 1;
|
|
if ((h->flags & ALUA_OPTIMIZE_STPG) &&
|
|
(!h->pref) &&
|
|
(h->tpgs & TPGS_MODE_IMPLICIT))
|
|
stpg = 0;
|
|
break;
|
|
case TPGS_STATE_STANDBY:
|
|
case TPGS_STATE_UNAVAILABLE:
|
|
stpg = 1;
|
|
break;
|
|
case TPGS_STATE_OFFLINE:
|
|
err = SCSI_DH_IO;
|
|
break;
|
|
case TPGS_STATE_TRANSITIONING:
|
|
err = SCSI_DH_RETRY;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (stpg) {
|
|
h->callback_fn = fn;
|
|
h->callback_data = data;
|
|
err = submit_stpg(h);
|
|
if (err == SCSI_DH_OK)
|
|
return 0;
|
|
h->callback_fn = h->callback_data = NULL;
|
|
}
|
|
|
|
out:
|
|
if (fn)
|
|
fn(data, err);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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 = sdev->handler_data;
|
|
int ret = BLKPREP_OK;
|
|
|
|
if (h->state == TPGS_STATE_TRANSITIONING)
|
|
ret = BLKPREP_DEFER;
|
|
else if (h->state != TPGS_STATE_OPTIMIZED &&
|
|
h->state != TPGS_STATE_NONOPTIMIZED &&
|
|
h->state != TPGS_STATE_LBA_DEPENDENT) {
|
|
ret = BLKPREP_KILL;
|
|
req->cmd_flags |= REQ_QUIET;
|
|
}
|
|
return ret;
|
|
|
|
}
|
|
|
|
/*
|
|
* alua_bus_attach - Attach device handler
|
|
* @sdev: device to be attached to
|
|
*/
|
|
static int alua_bus_attach(struct scsi_device *sdev)
|
|
{
|
|
struct alua_dh_data *h;
|
|
int err;
|
|
|
|
h = kzalloc(sizeof(*h) , GFP_KERNEL);
|
|
if (!h)
|
|
return -ENOMEM;
|
|
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;
|
|
h->sdev = sdev;
|
|
|
|
err = alua_initialize(sdev, h);
|
|
if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED)
|
|
goto failed;
|
|
|
|
sdev->handler_data = h;
|
|
return 0;
|
|
failed:
|
|
kfree(h);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* alua_bus_detach - Detach device handler
|
|
* @sdev: device to be detached from
|
|
*/
|
|
static void alua_bus_detach(struct scsi_device *sdev)
|
|
{
|
|
struct alua_dh_data *h = sdev->handler_data;
|
|
|
|
if (h->buff && h->inq != h->buff)
|
|
kfree(h->buff);
|
|
sdev->handler_data = NULL;
|
|
kfree(h);
|
|
}
|
|
|
|
static struct scsi_device_handler alua_dh = {
|
|
.name = ALUA_DH_NAME,
|
|
.module = THIS_MODULE,
|
|
.attach = alua_bus_attach,
|
|
.detach = alua_bus_detach,
|
|
.prep_fn = alua_prep_fn,
|
|
.check_sense = alua_check_sense,
|
|
.activate = alua_activate,
|
|
.set_params = alua_set_params,
|
|
};
|
|
|
|
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);
|