| /* |
| * Generic SCSI-3 ALUA SCSI Device Handler |
| * |
| * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH. |
| * All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| * |
| */ |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/module.h> |
| #include <scsi/scsi.h> |
| #include <scsi/scsi_eh.h> |
| #include <scsi/scsi_dh.h> |
| |
| #define ALUA_DH_NAME "alua" |
| #define ALUA_DH_VER "1.3" |
| |
| #define TPGS_STATE_OPTIMIZED 0x0 |
| #define TPGS_STATE_NONOPTIMIZED 0x1 |
| #define TPGS_STATE_STANDBY 0x2 |
| #define TPGS_STATE_UNAVAILABLE 0x3 |
| #define TPGS_STATE_LBA_DEPENDENT 0x4 |
| #define TPGS_STATE_OFFLINE 0xe |
| #define TPGS_STATE_TRANSITIONING 0xf |
| |
| #define TPGS_SUPPORT_NONE 0x00 |
| #define TPGS_SUPPORT_OPTIMIZED 0x01 |
| #define TPGS_SUPPORT_NONOPTIMIZED 0x02 |
| #define TPGS_SUPPORT_STANDBY 0x04 |
| #define TPGS_SUPPORT_UNAVAILABLE 0x08 |
| #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 |
| #define TPGS_SUPPORT_OFFLINE 0x40 |
| #define TPGS_SUPPORT_TRANSITION 0x80 |
| |
| #define RTPG_FMT_MASK 0x70 |
| #define RTPG_FMT_EXT_HDR 0x10 |
| |
| #define TPGS_MODE_UNINITIALIZED -1 |
| #define TPGS_MODE_NONE 0x0 |
| #define TPGS_MODE_IMPLICIT 0x1 |
| #define TPGS_MODE_EXPLICIT 0x2 |
| |
| #define ALUA_INQUIRY_SIZE 36 |
| #define ALUA_FAILOVER_TIMEOUT 60 |
| #define ALUA_FAILOVER_RETRIES 5 |
| |
| /* flags passed from user level */ |
| #define ALUA_OPTIMIZE_STPG 1 |
| |
| struct alua_dh_data { |
| int group_id; |
| int rel_port; |
| int tpgs; |
| int state; |
| int pref; |
| unsigned flags; /* used for optimizing STPG */ |
| unsigned char inq[ALUA_INQUIRY_SIZE]; |
| unsigned char *buff; |
| int bufflen; |
| unsigned char transition_tmo; |
| unsigned char sense[SCSI_SENSE_BUFFERSIZE]; |
| int senselen; |
| struct scsi_device *sdev; |
| activate_complete callback_fn; |
| void *callback_data; |
| }; |
| |
| #define ALUA_POLICY_SWITCH_CURRENT 0 |
| #define ALUA_POLICY_SWITCH_ALL 1 |
| |
| static char print_alua_state(int); |
| static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); |
| |
| static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev) |
| { |
| struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; |
| BUG_ON(scsi_dh_data == NULL); |
| return ((struct alua_dh_data *) scsi_dh_data->buf); |
| } |
| |
| static int realloc_buffer(struct alua_dh_data *h, unsigned len) |
| { |
| if (h->buff && h->buff != h->inq) |
| kfree(h->buff); |
| |
| h->buff = kmalloc(len, GFP_NOIO); |
| if (!h->buff) { |
| h->buff = h->inq; |
| h->bufflen = ALUA_INQUIRY_SIZE; |
| return 1; |
| } |
| h->bufflen = len; |
| return 0; |
| } |
| |
| static struct request *get_alua_req(struct scsi_device *sdev, |
| void *buffer, unsigned buflen, int rw) |
| { |
| struct request *rq; |
| struct request_queue *q = sdev->request_queue; |
| |
| rq = blk_get_request(q, rw, GFP_NOIO); |
| |
| if (IS_ERR(rq)) { |
| sdev_printk(KERN_INFO, sdev, |
| "%s: blk_get_request failed\n", __func__); |
| return NULL; |
| } |
| blk_rq_set_block_pc(rq); |
| |
| if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) { |
| blk_put_request(rq); |
| sdev_printk(KERN_INFO, sdev, |
| "%s: blk_rq_map_kern failed\n", __func__); |
| return NULL; |
| } |
| |
| rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | |
| REQ_FAILFAST_DRIVER; |
| rq->retries = ALUA_FAILOVER_RETRIES; |
| rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; |
| |
| return rq; |
| } |
| |
| /* |
| * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command |
| * @sdev: sdev the command should be sent to |
| */ |
| static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) |
| { |
| struct request *rq; |
| int err = SCSI_DH_RES_TEMP_UNAVAIL; |
| |
| rq = get_alua_req(sdev, h->buff, h->bufflen, READ); |
| if (!rq) |
| goto done; |
| |
| /* Prepare the command. */ |
| rq->cmd[0] = INQUIRY; |
| rq->cmd[1] = 1; |
| rq->cmd[2] = 0x83; |
| rq->cmd[4] = h->bufflen; |
| rq->cmd_len = COMMAND_SIZE(INQUIRY); |
| |
| rq->sense = h->sense; |
| memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); |
| rq->sense_len = h->senselen = 0; |
| |
| err = blk_execute_rq(rq->q, NULL, rq, 1); |
| if (err == -EIO) { |
| sdev_printk(KERN_INFO, sdev, |
| "%s: evpd inquiry failed with %x\n", |
| ALUA_DH_NAME, rq->errors); |
| h->senselen = rq->sense_len; |
| err = SCSI_DH_IO; |
| } |
| blk_put_request(rq); |
| done: |
| return err; |
| } |
| |
| /* |
| * 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, |
| bool rtpg_ext_hdr_req) |
| { |
| struct request *rq; |
| int err = SCSI_DH_RES_TEMP_UNAVAIL; |
| |
| rq = get_alua_req(sdev, h->buff, h->bufflen, READ); |
| if (!rq) |
| goto done; |
| |
| /* Prepare the command. */ |
| rq->cmd[0] = MAINTENANCE_IN; |
| 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; |
| rq->cmd[9] = h->bufflen & 0xff; |
| rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN); |
| |
| rq->sense = h->sense; |
| memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); |
| rq->sense_len = h->senselen = 0; |
| |
| err = blk_execute_rq(rq->q, NULL, rq, 1); |
| if (err == -EIO) { |
| sdev_printk(KERN_INFO, sdev, |
| "%s: rtpg failed with %x\n", |
| ALUA_DH_NAME, rq->errors); |
| h->senselen = rq->sense_len; |
| err = SCSI_DH_IO; |
| } |
| blk_put_request(rq); |
| done: |
| return err; |
| } |
| |
| /* |
| * alua_stpg - Evaluate SET TARGET GROUP STATES |
| * @sdev: the device to be evaluated |
| * @state: the new target group state |
| * |
| * Send a SET TARGET GROUP STATES command to the device. |
| * We only have to test here if we should resubmit the command; |
| * any other error is assumed as a failure. |
| */ |
| static void stpg_endio(struct request *req, int error) |
| { |
| struct alua_dh_data *h = req->end_io_data; |
| struct scsi_sense_hdr sense_hdr; |
| unsigned err = SCSI_DH_OK; |
| |
| if (host_byte(req->errors) != DID_OK || |
| msg_byte(req->errors) != COMMAND_COMPLETE) { |
| err = SCSI_DH_IO; |
| goto done; |
| } |
| |
| if (req->sense_len > 0) { |
| err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, |
| &sense_hdr); |
| if (!err) { |
| err = SCSI_DH_IO; |
| goto done; |
| } |
| err = alua_check_sense(h->sdev, &sense_hdr); |
| if (err == ADD_TO_MLQUEUE) { |
| err = SCSI_DH_RETRY; |
| goto done; |
| } |
| sdev_printk(KERN_INFO, h->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; |
| } else if (error) |
| err = SCSI_DH_IO; |
| |
| if (err == SCSI_DH_OK) { |
| h->state = TPGS_STATE_OPTIMIZED; |
| sdev_printk(KERN_INFO, h->sdev, |
| "%s: port group %02x switched to state %c\n", |
| ALUA_DH_NAME, h->group_id, |
| print_alua_state(h->state)); |
| } |
| done: |
| req->end_io_data = NULL; |
| __blk_put_request(req->q, req); |
| if (h->callback_fn) { |
| h->callback_fn(h->callback_data, err); |
| h->callback_fn = h->callback_data = NULL; |
| } |
| return; |
| } |
| |
| /* |
| * submit_stpg - Issue a SET TARGET GROUP STATES command |
| * |
| * Currently we're only setting the current target port group state |
| * to 'active/optimized' and let the array firmware figure out |
| * the states of the remaining groups. |
| */ |
| static unsigned submit_stpg(struct alua_dh_data *h) |
| { |
| struct request *rq; |
| int stpg_len = 8; |
| struct scsi_device *sdev = h->sdev; |
| |
| /* Prepare the data buffer */ |
| memset(h->buff, 0, stpg_len); |
| h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f; |
| h->buff[6] = (h->group_id >> 8) & 0xff; |
| h->buff[7] = h->group_id & 0xff; |
| |
| rq = get_alua_req(sdev, h->buff, stpg_len, WRITE); |
| if (!rq) |
| return SCSI_DH_RES_TEMP_UNAVAIL; |
| |
| /* Prepare the command. */ |
| rq->cmd[0] = MAINTENANCE_OUT; |
| rq->cmd[1] = MO_SET_TARGET_PGS; |
| rq->cmd[6] = (stpg_len >> 24) & 0xff; |
| rq->cmd[7] = (stpg_len >> 16) & 0xff; |
| rq->cmd[8] = (stpg_len >> 8) & 0xff; |
| rq->cmd[9] = stpg_len & 0xff; |
| rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT); |
| |
| rq->sense = h->sense; |
| memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); |
| rq->sense_len = h->senselen = 0; |
| rq->end_io_data = h; |
| |
| blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio); |
| return SCSI_DH_OK; |
| } |
| |
| /* |
| * alua_check_tpgs - Evaluate TPGS setting |
| * @sdev: device to be checked |
| * |
| * Examine the TPGS setting of the sdev to find out if ALUA |
| * is supported. |
| */ |
| static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h) |
| { |
| int err = SCSI_DH_OK; |
| |
| h->tpgs = scsi_device_tpgs(sdev); |
| switch (h->tpgs) { |
| case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT: |
| sdev_printk(KERN_INFO, sdev, |
| "%s: supports implicit and explicit TPGS\n", |
| ALUA_DH_NAME); |
| break; |
| case TPGS_MODE_EXPLICIT: |
| sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n", |
| ALUA_DH_NAME); |
| break; |
| case TPGS_MODE_IMPLICIT: |
| sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n", |
| ALUA_DH_NAME); |
| break; |
| default: |
| h->tpgs = TPGS_MODE_NONE; |
| sdev_printk(KERN_INFO, sdev, "%s: not supported\n", |
| ALUA_DH_NAME); |
| err = SCSI_DH_DEV_UNSUPP; |
| break; |
| } |
| |
| return err; |
| } |
| |
| /* |
| * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83 |
| * @sdev: device to be checked |
| * |
| * Extract the relative target port and the target port group |
| * descriptor from the list of identificators. |
| */ |
| static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h) |
| { |
| int len; |
| unsigned err; |
| unsigned char *d; |
| |
| retry: |
| err = submit_vpd_inquiry(sdev, h); |
| |
| if (err != SCSI_DH_OK) |
| return err; |
| |
| /* Check if vpd page exceeds initial buffer */ |
| len = (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", |
| ALUA_DH_NAME); |
| /* Temporary failure, bypass */ |
| return SCSI_DH_DEV_TEMP_BUSY; |
| } |
| goto retry; |
| } |
| |
| /* |
| * Now look for the correct descriptor. |
| */ |
| d = h->buff + 4; |
| while (d < h->buff + len) { |
| switch (d[1] & 0xf) { |
| case 0x4: |
| /* Relative target port */ |
| h->rel_port = (d[6] << 8) + d[7]; |
| break; |
| case 0x5: |
| /* Target port group */ |
| h->group_id = (d[6] << 8) + d[7]; |
| break; |
| default: |
| break; |
| } |
| d += d[3] + 4; |
| } |
| |
| if (h->group_id == -1) { |
| /* |
| * Internal error; TPGS supported but required |
| * VPD identification descriptors not present. |
| * Disable ALUA support |
| */ |
| sdev_printk(KERN_INFO, sdev, |
| "%s: No target port descriptors found\n", |
| ALUA_DH_NAME); |
| h->state = TPGS_STATE_OPTIMIZED; |
| h->tpgs = TPGS_MODE_NONE; |
| err = SCSI_DH_DEV_UNSUPP; |
| } else { |
| sdev_printk(KERN_INFO, sdev, |
| "%s: port group %02x rel port %02x\n", |
| ALUA_DH_NAME, h->group_id, h->rel_port); |
| } |
| |
| return err; |
| } |
| |
| static char print_alua_state(int state) |
| { |
| switch (state) { |
| case TPGS_STATE_OPTIMIZED: |
| return 'A'; |
| case TPGS_STATE_NONOPTIMIZED: |
| return 'N'; |
| case TPGS_STATE_STANDBY: |
| return 'S'; |
| case TPGS_STATE_UNAVAILABLE: |
| return 'U'; |
| case TPGS_STATE_LBA_DEPENDENT: |
| return 'L'; |
| case TPGS_STATE_OFFLINE: |
| return 'O'; |
| case TPGS_STATE_TRANSITIONING: |
| return 'T'; |
| default: |
| return 'X'; |
| } |
| } |
| |
| static int alua_check_sense(struct scsi_device *sdev, |
| struct scsi_sense_hdr *sense_hdr) |
| { |
| switch (sense_hdr->sense_key) { |
| case NOT_READY: |
| if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0a) |
| /* |
| * LUN Not Accessible - ALUA state transition |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0b) |
| /* |
| * LUN Not Accessible -- Target port in standby state |
| */ |
| return SUCCESS; |
| if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x0c) |
| /* |
| * LUN Not Accessible -- Target port in unavailable state |
| */ |
| return SUCCESS; |
| if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x12) |
| /* |
| * LUN Not Ready -- Offline |
| */ |
| return SUCCESS; |
| if (sdev->allow_restart && |
| sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x02) |
| /* |
| * if the device is not started, we need to wake |
| * the error handler to start the motor |
| */ |
| return FAILED; |
| break; |
| case UNIT_ATTENTION: |
| if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) |
| /* |
| * Power On, Reset, or Bus Device Reset, just retry. |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) |
| /* |
| * Device internal reset |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) |
| /* |
| * Mode Parameters Changed |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) |
| /* |
| * ALUA state changed |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) |
| /* |
| * Implicit ALUA state transition failed |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x03) |
| /* |
| * Inquiry data has changed |
| */ |
| return ADD_TO_MLQUEUE; |
| if (sense_hdr->asc == 0x3f && sense_hdr->ascq == 0x0e) |
| /* |
| * REPORTED_LUNS_DATA_HAS_CHANGED is reported |
| * when switching controllers on targets like |
| * Intel Multi-Flex. We can just retry. |
| */ |
| return ADD_TO_MLQUEUE; |
| break; |
| } |
| |
| return SCSI_RETURN_NOT_HANDLED; |
| } |
| |
| /* |
| * alua_rtpg - Evaluate REPORT TARGET GROUP STATES |
| * @sdev: the device to be evaluated. |
| * @wait_for_transition: if nonzero, wait ALUA_FAILOVER_TIMEOUT seconds for device to exit transitioning state |
| * |
| * Evaluate the Target Port Group State. |
| * Returns SCSI_DH_DEV_OFFLINED if the path is |
| * found to be unusable. |
| */ |
| static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition) |
| { |
| struct scsi_sense_hdr sense_hdr; |
| int len, k, off, valid_states = 0; |
| unsigned char *ucp; |
| unsigned err; |
| bool rtpg_ext_hdr_req = 1; |
| unsigned long expiry, interval = 0; |
| unsigned int tpg_desc_tbl_off; |
| unsigned char orig_transition_tmo; |
| |
| if (!h->transition_tmo) |
| expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ); |
| else |
| expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); |
| |
| retry: |
| 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, |
| &sense_hdr); |
| 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; |
| 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; |
| } |
| |
| 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 == (ucp[2] << 8) + ucp[3]) { |
| 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; |
| |
| err = alua_check_tpgs(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, 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 = get_alua_data(sdev); |
| 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 = get_alua_data(sdev); |
| 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 = get_alua_data(sdev); |
| 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; |
| |
| } |
| |
| static bool alua_match(struct scsi_device *sdev) |
| { |
| return (scsi_device_tpgs(sdev) != 0); |
| } |
| |
| 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, |
| .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, |
| .match = alua_match, |
| }; |
| |
| /* |
| * 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(*scsi_dh_data) |
| + 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; |
| h->sdev = sdev; |
| |
| err = alua_initialize(sdev, h); |
| if ((err != SCSI_DH_OK) && (err != SCSI_DH_DEV_OFFLINED)) |
| 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); |
| sdev_printk(KERN_NOTICE, sdev, "%s: Attached\n", ALUA_DH_NAME); |
| |
| 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); |