Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / scsi / device_handler / scsi_dh_rdac.c
diff --git a/kernel/drivers/scsi/device_handler/scsi_dh_rdac.c b/kernel/drivers/scsi/device_handler/scsi_dh_rdac.c
new file mode 100644 (file)
index 0000000..b46ace3
--- /dev/null
@@ -0,0 +1,937 @@
+/*
+ * LSI/Engenio/NetApp E-Series RDAC SCSI Device Handler
+ *
+ * Copyright (C) 2005 Mike Christie. All rights reserved.
+ * Copyright (C) Chandra Seetharaman, IBM Corp. 2007
+ *
+ * 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 <scsi/scsi.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_dh.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define RDAC_NAME "rdac"
+#define RDAC_RETRY_COUNT 5
+
+/*
+ * LSI mode page stuff
+ *
+ * These struct definitions and the forming of the
+ * mode page were taken from the LSI RDAC 2.4 GPL'd
+ * driver, and then converted to Linux conventions.
+ */
+#define RDAC_QUIESCENCE_TIME 20
+/*
+ * Page Codes
+ */
+#define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
+
+/*
+ * Controller modes definitions
+ */
+#define RDAC_MODE_TRANSFER_SPECIFIED_LUNS      0x02
+
+/*
+ * RDAC Options field
+ */
+#define RDAC_FORCED_QUIESENCE 0x02
+
+#define RDAC_TIMEOUT   (60 * HZ)
+#define RDAC_RETRIES   3
+
+struct rdac_mode_6_hdr {
+       u8      data_len;
+       u8      medium_type;
+       u8      device_params;
+       u8      block_desc_len;
+};
+
+struct rdac_mode_10_hdr {
+       u16     data_len;
+       u8      medium_type;
+       u8      device_params;
+       u16     reserved;
+       u16     block_desc_len;
+};
+
+struct rdac_mode_common {
+       u8      controller_serial[16];
+       u8      alt_controller_serial[16];
+       u8      rdac_mode[2];
+       u8      alt_rdac_mode[2];
+       u8      quiescence_timeout;
+       u8      rdac_options;
+};
+
+struct rdac_pg_legacy {
+       struct rdac_mode_6_hdr hdr;
+       u8      page_code;
+       u8      page_len;
+       struct rdac_mode_common common;
+#define MODE6_MAX_LUN  32
+       u8      lun_table[MODE6_MAX_LUN];
+       u8      reserved2[32];
+       u8      reserved3;
+       u8      reserved4;
+};
+
+struct rdac_pg_expanded {
+       struct rdac_mode_10_hdr hdr;
+       u8      page_code;
+       u8      subpage_code;
+       u8      page_len[2];
+       struct rdac_mode_common common;
+       u8      lun_table[256];
+       u8      reserved3;
+       u8      reserved4;
+};
+
+struct c9_inquiry {
+       u8      peripheral_info;
+       u8      page_code;      /* 0xC9 */
+       u8      reserved1;
+       u8      page_len;
+       u8      page_id[4];     /* "vace" */
+       u8      avte_cvp;
+       u8      path_prio;
+       u8      reserved2[38];
+};
+
+#define SUBSYS_ID_LEN  16
+#define SLOT_ID_LEN    2
+#define ARRAY_LABEL_LEN        31
+
+struct c4_inquiry {
+       u8      peripheral_info;
+       u8      page_code;      /* 0xC4 */
+       u8      reserved1;
+       u8      page_len;
+       u8      page_id[4];     /* "subs" */
+       u8      subsys_id[SUBSYS_ID_LEN];
+       u8      revision[4];
+       u8      slot_id[SLOT_ID_LEN];
+       u8      reserved[2];
+};
+
+#define UNIQUE_ID_LEN 16
+struct c8_inquiry {
+       u8      peripheral_info;
+       u8      page_code; /* 0xC8 */
+       u8      reserved1;
+       u8      page_len;
+       u8      page_id[4]; /* "edid" */
+       u8      reserved2[3];
+       u8      vol_uniq_id_len;
+       u8      vol_uniq_id[16];
+       u8      vol_user_label_len;
+       u8      vol_user_label[60];
+       u8      array_uniq_id_len;
+       u8      array_unique_id[UNIQUE_ID_LEN];
+       u8      array_user_label_len;
+       u8      array_user_label[60];
+       u8      lun[8];
+};
+
+struct rdac_controller {
+       u8                      array_id[UNIQUE_ID_LEN];
+       int                     use_ms10;
+       struct kref             kref;
+       struct list_head        node; /* list of all controllers */
+       union                   {
+               struct rdac_pg_legacy legacy;
+               struct rdac_pg_expanded expanded;
+       } mode_select;
+       u8      index;
+       u8      array_name[ARRAY_LABEL_LEN];
+       struct Scsi_Host        *host;
+       spinlock_t              ms_lock;
+       int                     ms_queued;
+       struct work_struct      ms_work;
+       struct scsi_device      *ms_sdev;
+       struct list_head        ms_head;
+};
+
+struct c2_inquiry {
+       u8      peripheral_info;
+       u8      page_code;      /* 0xC2 */
+       u8      reserved1;
+       u8      page_len;
+       u8      page_id[4];     /* "swr4" */
+       u8      sw_version[3];
+       u8      sw_date[3];
+       u8      features_enabled;
+       u8      max_lun_supported;
+       u8      partitions[239]; /* Total allocation length should be 0xFF */
+};
+
+struct rdac_dh_data {
+       struct scsi_dh_data     dh_data;
+       struct rdac_controller  *ctlr;
+#define UNINITIALIZED_LUN      (1 << 8)
+       unsigned                lun;
+
+#define RDAC_MODE              0
+#define RDAC_MODE_AVT          1
+#define RDAC_MODE_IOSHIP       2
+       unsigned char           mode;
+
+#define RDAC_STATE_ACTIVE      0
+#define RDAC_STATE_PASSIVE     1
+       unsigned char           state;
+
+#define RDAC_LUN_UNOWNED       0
+#define RDAC_LUN_OWNED         1
+       char                    lun_state;
+
+#define RDAC_PREFERRED         0
+#define RDAC_NON_PREFERRED     1
+       char                    preferred;
+
+       unsigned char           sense[SCSI_SENSE_BUFFERSIZE];
+       union                   {
+               struct c2_inquiry c2;
+               struct c4_inquiry c4;
+               struct c8_inquiry c8;
+               struct c9_inquiry c9;
+       } inq;
+};
+
+static const char *mode[] = {
+       "RDAC",
+       "AVT",
+       "IOSHIP",
+};
+static const char *lun_state[] =
+{
+       "unowned",
+       "owned",
+};
+
+struct rdac_queue_data {
+       struct list_head        entry;
+       struct rdac_dh_data     *h;
+       activate_complete       callback_fn;
+       void                    *callback_data;
+};
+
+static LIST_HEAD(ctlr_list);
+static DEFINE_SPINLOCK(list_lock);
+static struct workqueue_struct *kmpath_rdacd;
+static void send_mode_select(struct work_struct *work);
+
+/*
+ * module parameter to enable rdac debug logging.
+ * 2 bits for each type of logging, only two types defined for now
+ * Can be enhanced if required at later point
+ */
+static int rdac_logging = 1;
+module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
+               "Default is 1 - failover logging enabled, "
+               "set it to 0xF to enable all the logs");
+
+#define RDAC_LOG_FAILOVER      0
+#define RDAC_LOG_SENSE         2
+
+#define RDAC_LOG_BITS          2
+
+#define RDAC_LOG_LEVEL(SHIFT)  \
+       ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
+
+#define RDAC_LOG(SHIFT, sdev, f, arg...) \
+do { \
+       if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
+               sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
+} while (0);
+
+static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
+{
+       return container_of(sdev->scsi_dh_data, struct rdac_dh_data, dh_data);
+}
+
+static struct request *get_rdac_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,
+                               "get_rdac_req: blk_get_request failed.\n");
+               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,
+                               "get_rdac_req: blk_rq_map_kern failed.\n");
+               return NULL;
+       }
+
+       rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
+                        REQ_FAILFAST_DRIVER;
+       rq->retries = RDAC_RETRIES;
+       rq->timeout = RDAC_TIMEOUT;
+
+       return rq;
+}
+
+static struct request *rdac_failover_get(struct scsi_device *sdev,
+                       struct rdac_dh_data *h, struct list_head *list)
+{
+       struct request *rq;
+       struct rdac_mode_common *common;
+       unsigned data_size;
+       struct rdac_queue_data *qdata;
+       u8 *lun_table;
+
+       if (h->ctlr->use_ms10) {
+               struct rdac_pg_expanded *rdac_pg;
+
+               data_size = sizeof(struct rdac_pg_expanded);
+               rdac_pg = &h->ctlr->mode_select.expanded;
+               memset(rdac_pg, 0, data_size);
+               common = &rdac_pg->common;
+               rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
+               rdac_pg->subpage_code = 0x1;
+               rdac_pg->page_len[0] = 0x01;
+               rdac_pg->page_len[1] = 0x28;
+               lun_table = rdac_pg->lun_table;
+       } else {
+               struct rdac_pg_legacy *rdac_pg;
+
+               data_size = sizeof(struct rdac_pg_legacy);
+               rdac_pg = &h->ctlr->mode_select.legacy;
+               memset(rdac_pg, 0, data_size);
+               common = &rdac_pg->common;
+               rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
+               rdac_pg->page_len = 0x68;
+               lun_table = rdac_pg->lun_table;
+       }
+       common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
+       common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
+       common->rdac_options = RDAC_FORCED_QUIESENCE;
+
+       list_for_each_entry(qdata, list, entry) {
+               lun_table[qdata->h->lun] = 0x81;
+       }
+
+       /* get request for block layer packet command */
+       rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
+       if (!rq)
+               return NULL;
+
+       /* Prepare the command. */
+       if (h->ctlr->use_ms10) {
+               rq->cmd[0] = MODE_SELECT_10;
+               rq->cmd[7] = data_size >> 8;
+               rq->cmd[8] = data_size & 0xff;
+       } else {
+               rq->cmd[0] = MODE_SELECT;
+               rq->cmd[4] = data_size;
+       }
+       rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
+
+       rq->sense = h->sense;
+       memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
+       rq->sense_len = 0;
+
+       return rq;
+}
+
+static void release_controller(struct kref *kref)
+{
+       struct rdac_controller *ctlr;
+       ctlr = container_of(kref, struct rdac_controller, kref);
+
+       list_del(&ctlr->node);
+       kfree(ctlr);
+}
+
+static struct rdac_controller *get_controller(int index, char *array_name,
+                       u8 *array_id, struct scsi_device *sdev)
+{
+       struct rdac_controller *ctlr, *tmp;
+
+       list_for_each_entry(tmp, &ctlr_list, node) {
+               if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
+                         (tmp->index == index) &&
+                         (tmp->host == sdev->host)) {
+                       kref_get(&tmp->kref);
+                       return tmp;
+               }
+       }
+       ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
+       if (!ctlr)
+               return NULL;
+
+       /* initialize fields of controller */
+       memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
+       ctlr->index = index;
+       ctlr->host = sdev->host;
+       memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
+
+       kref_init(&ctlr->kref);
+       ctlr->use_ms10 = -1;
+       ctlr->ms_queued = 0;
+       ctlr->ms_sdev = NULL;
+       spin_lock_init(&ctlr->ms_lock);
+       INIT_WORK(&ctlr->ms_work, send_mode_select);
+       INIT_LIST_HEAD(&ctlr->ms_head);
+       list_add(&ctlr->node, &ctlr_list);
+
+       return ctlr;
+}
+
+static int submit_inquiry(struct scsi_device *sdev, int page_code,
+                         unsigned int len, struct rdac_dh_data *h)
+{
+       struct request *rq;
+       struct request_queue *q = sdev->request_queue;
+       int err = SCSI_DH_RES_TEMP_UNAVAIL;
+
+       rq = get_rdac_req(sdev, &h->inq, len, READ);
+       if (!rq)
+               goto done;
+
+       /* Prepare the command. */
+       rq->cmd[0] = INQUIRY;
+       rq->cmd[1] = 1;
+       rq->cmd[2] = page_code;
+       rq->cmd[4] = len;
+       rq->cmd_len = COMMAND_SIZE(INQUIRY);
+
+       rq->sense = h->sense;
+       memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
+       rq->sense_len = 0;
+
+       err = blk_execute_rq(q, NULL, rq, 1);
+       if (err == -EIO)
+               err = SCSI_DH_IO;
+
+       blk_put_request(rq);
+done:
+       return err;
+}
+
+static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
+                       char *array_name, u8 *array_id)
+{
+       int err, i;
+       struct c8_inquiry *inqp;
+
+       err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
+       if (err == SCSI_DH_OK) {
+               inqp = &h->inq.c8;
+               if (inqp->page_code != 0xc8)
+                       return SCSI_DH_NOSYS;
+               if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
+                   inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
+                       return SCSI_DH_NOSYS;
+               h->lun = inqp->lun[7]; /* Uses only the last byte */
+
+               for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
+                       *(array_name+i) = inqp->array_user_label[(2*i)+1];
+
+               *(array_name+ARRAY_LABEL_LEN-1) = '\0';
+               memset(array_id, 0, UNIQUE_ID_LEN);
+               memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
+       }
+       return err;
+}
+
+static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
+{
+       int err;
+       struct c9_inquiry *inqp;
+
+       h->state = RDAC_STATE_ACTIVE;
+       err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
+       if (err == SCSI_DH_OK) {
+               inqp = &h->inq.c9;
+               /* detect the operating mode */
+               if ((inqp->avte_cvp >> 5) & 0x1)
+                       h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
+               else if (inqp->avte_cvp >> 7)
+                       h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
+               else
+                       h->mode = RDAC_MODE; /* LUN in RDAC mode */
+
+               /* Update ownership */
+               if (inqp->avte_cvp & 0x1)
+                       h->lun_state = RDAC_LUN_OWNED;
+               else {
+                       h->lun_state = RDAC_LUN_UNOWNED;
+                       if (h->mode == RDAC_MODE)
+                               h->state = RDAC_STATE_PASSIVE;
+               }
+
+               /* Update path prio*/
+               if (inqp->path_prio & 0x1)
+                       h->preferred = RDAC_PREFERRED;
+               else
+                       h->preferred = RDAC_NON_PREFERRED;
+       }
+
+       return err;
+}
+
+static int initialize_controller(struct scsi_device *sdev,
+               struct rdac_dh_data *h, char *array_name, u8 *array_id)
+{
+       int err, index;
+       struct c4_inquiry *inqp;
+
+       err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
+       if (err == SCSI_DH_OK) {
+               inqp = &h->inq.c4;
+               /* get the controller index */
+               if (inqp->slot_id[1] == 0x31)
+                       index = 0;
+               else
+                       index = 1;
+
+               spin_lock(&list_lock);
+               h->ctlr = get_controller(index, array_name, array_id, sdev);
+               if (!h->ctlr)
+                       err = SCSI_DH_RES_TEMP_UNAVAIL;
+               spin_unlock(&list_lock);
+       }
+       return err;
+}
+
+static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
+{
+       int err;
+       struct c2_inquiry *inqp;
+
+       err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
+       if (err == SCSI_DH_OK) {
+               inqp = &h->inq.c2;
+               /*
+                * If more than MODE6_MAX_LUN luns are supported, use
+                * mode select 10
+                */
+               if (inqp->max_lun_supported >= MODE6_MAX_LUN)
+                       h->ctlr->use_ms10 = 1;
+               else
+                       h->ctlr->use_ms10 = 0;
+       }
+       return err;
+}
+
+static int mode_select_handle_sense(struct scsi_device *sdev,
+                                       unsigned char *sensebuf)
+{
+       struct scsi_sense_hdr sense_hdr;
+       int err = SCSI_DH_IO, ret;
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+
+       ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
+       if (!ret)
+               goto done;
+
+       switch (sense_hdr.sense_key) {
+       case NO_SENSE:
+       case ABORTED_COMMAND:
+       case UNIT_ATTENTION:
+               err = SCSI_DH_RETRY;
+               break;
+       case NOT_READY:
+               if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
+                       /* LUN Not Ready and is in the Process of Becoming
+                        * Ready
+                        */
+                       err = SCSI_DH_RETRY;
+               break;
+       case ILLEGAL_REQUEST:
+               if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
+                       /*
+                        * Command Lock contention
+                        */
+                       err = SCSI_DH_RETRY;
+               break;
+       default:
+               break;
+       }
+
+       RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+               "MODE_SELECT returned with sense %02x/%02x/%02x",
+               (char *) h->ctlr->array_name, h->ctlr->index,
+               sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
+
+done:
+       return err;
+}
+
+static void send_mode_select(struct work_struct *work)
+{
+       struct rdac_controller *ctlr =
+               container_of(work, struct rdac_controller, ms_work);
+       struct request *rq;
+       struct scsi_device *sdev = ctlr->ms_sdev;
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+       struct request_queue *q = sdev->request_queue;
+       int err, retry_cnt = RDAC_RETRY_COUNT;
+       struct rdac_queue_data *tmp, *qdata;
+       LIST_HEAD(list);
+
+       spin_lock(&ctlr->ms_lock);
+       list_splice_init(&ctlr->ms_head, &list);
+       ctlr->ms_queued = 0;
+       ctlr->ms_sdev = NULL;
+       spin_unlock(&ctlr->ms_lock);
+
+retry:
+       err = SCSI_DH_RES_TEMP_UNAVAIL;
+       rq = rdac_failover_get(sdev, h, &list);
+       if (!rq)
+               goto done;
+
+       RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+               "%s MODE_SELECT command",
+               (char *) h->ctlr->array_name, h->ctlr->index,
+               (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
+
+       err = blk_execute_rq(q, NULL, rq, 1);
+       blk_put_request(rq);
+       if (err != SCSI_DH_OK) {
+               err = mode_select_handle_sense(sdev, h->sense);
+               if (err == SCSI_DH_RETRY && retry_cnt--)
+                       goto retry;
+       }
+       if (err == SCSI_DH_OK) {
+               h->state = RDAC_STATE_ACTIVE;
+               RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
+                               "MODE_SELECT completed",
+                               (char *) h->ctlr->array_name, h->ctlr->index);
+       }
+
+done:
+       list_for_each_entry_safe(qdata, tmp, &list, entry) {
+               list_del(&qdata->entry);
+               if (err == SCSI_DH_OK)
+                       qdata->h->state = RDAC_STATE_ACTIVE;
+               if (qdata->callback_fn)
+                       qdata->callback_fn(qdata->callback_data, err);
+               kfree(qdata);
+       }
+       return;
+}
+
+static int queue_mode_select(struct scsi_device *sdev,
+                               activate_complete fn, void *data)
+{
+       struct rdac_queue_data *qdata;
+       struct rdac_controller *ctlr;
+
+       qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
+       if (!qdata)
+               return SCSI_DH_RETRY;
+
+       qdata->h = get_rdac_data(sdev);
+       qdata->callback_fn = fn;
+       qdata->callback_data = data;
+
+       ctlr = qdata->h->ctlr;
+       spin_lock(&ctlr->ms_lock);
+       list_add_tail(&qdata->entry, &ctlr->ms_head);
+       if (!ctlr->ms_queued) {
+               ctlr->ms_queued = 1;
+               ctlr->ms_sdev = sdev;
+               queue_work(kmpath_rdacd, &ctlr->ms_work);
+       }
+       spin_unlock(&ctlr->ms_lock);
+       return SCSI_DH_OK;
+}
+
+static int rdac_activate(struct scsi_device *sdev,
+                       activate_complete fn, void *data)
+{
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+       int err = SCSI_DH_OK;
+       int act = 0;
+
+       err = check_ownership(sdev, h);
+       if (err != SCSI_DH_OK)
+               goto done;
+
+       switch (h->mode) {
+       case RDAC_MODE:
+               if (h->lun_state == RDAC_LUN_UNOWNED)
+                       act = 1;
+               break;
+       case RDAC_MODE_IOSHIP:
+               if ((h->lun_state == RDAC_LUN_UNOWNED) &&
+                   (h->preferred == RDAC_PREFERRED))
+                       act = 1;
+               break;
+       default:
+               break;
+       }
+
+       if (act) {
+               err = queue_mode_select(sdev, fn, data);
+               if (err == SCSI_DH_OK)
+                       return 0;
+       }
+done:
+       if (fn)
+               fn(data, err);
+       return 0;
+}
+
+static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
+{
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+       int ret = BLKPREP_OK;
+
+       if (h->state != RDAC_STATE_ACTIVE) {
+               ret = BLKPREP_KILL;
+               req->cmd_flags |= REQ_QUIET;
+       }
+       return ret;
+
+}
+
+static int rdac_check_sense(struct scsi_device *sdev,
+                               struct scsi_sense_hdr *sense_hdr)
+{
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+
+       RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
+                       "I/O returned with sense %02x/%02x/%02x",
+                       (char *) h->ctlr->array_name, h->ctlr->index,
+                       sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
+
+       switch (sense_hdr->sense_key) {
+       case NOT_READY:
+               if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
+                       /* LUN Not Ready - Logical Unit Not Ready and is in
+                       * the process of becoming ready
+                       * Just retry.
+                       */
+                       return ADD_TO_MLQUEUE;
+               if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
+                       /* LUN Not Ready - Storage firmware incompatible
+                        * Manual code synchonisation required.
+                        *
+                        * Nothing we can do here. Try to bypass the path.
+                        */
+                       return SUCCESS;
+               if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
+                       /* LUN Not Ready - Quiescense in progress
+                        *
+                        * Just retry and wait.
+                        */
+                       return ADD_TO_MLQUEUE;
+               if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
+                       /* LUN Not Ready - Quiescense in progress
+                        * or has been achieved
+                        * Just retry.
+                        */
+                       return ADD_TO_MLQUEUE;
+               break;
+       case ILLEGAL_REQUEST:
+               if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
+                       /* Invalid Request - Current Logical Unit Ownership.
+                        * Controller is not the current owner of the LUN,
+                        * Fail the path, so that the other path be used.
+                        */
+                       h->state = RDAC_STATE_PASSIVE;
+                       return SUCCESS;
+               }
+               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 == 0x8b && sense_hdr->ascq == 0x02)
+                       /*
+                        * Quiescence in progress , just retry.
+                        */
+                       return ADD_TO_MLQUEUE;
+               break;
+       }
+       /* success just means we do not care what scsi-ml does */
+       return SCSI_RETURN_NOT_HANDLED;
+}
+
+static const struct {
+       char *vendor;
+       char *model;
+} rdac_dev_list[] = {
+       {"IBM", "1722"},
+       {"IBM", "1724"},
+       {"IBM", "1726"},
+       {"IBM", "1742"},
+       {"IBM", "1745"},
+       {"IBM", "1746"},
+       {"IBM", "1813"},
+       {"IBM", "1814"},
+       {"IBM", "1815"},
+       {"IBM", "1818"},
+       {"IBM", "3526"},
+       {"SGI", "TP9"},
+       {"SGI", "IS"},
+       {"STK", "OPENstorage D280"},
+       {"STK", "FLEXLINE 380"},
+       {"SUN", "CSM"},
+       {"SUN", "LCSM100"},
+       {"SUN", "STK6580_6780"},
+       {"SUN", "SUN_6180"},
+       {"SUN", "ArrayStorage"},
+       {"DELL", "MD3"},
+       {"NETAPP", "INF-01-00"},
+       {"LSI", "INF-01-00"},
+       {"ENGENIO", "INF-01-00"},
+       {NULL, NULL},
+};
+
+static bool rdac_match(struct scsi_device *sdev)
+{
+       int i;
+
+       if (scsi_device_tpgs(sdev))
+               return false;
+
+       for (i = 0; rdac_dev_list[i].vendor; i++) {
+               if (!strncmp(sdev->vendor, rdac_dev_list[i].vendor,
+                       strlen(rdac_dev_list[i].vendor)) &&
+                   !strncmp(sdev->model, rdac_dev_list[i].model,
+                       strlen(rdac_dev_list[i].model))) {
+                       return true;
+               }
+       }
+       return false;
+}
+
+static struct scsi_dh_data *rdac_bus_attach(struct scsi_device *sdev)
+{
+       struct rdac_dh_data *h;
+       int err;
+       char array_name[ARRAY_LABEL_LEN];
+       char array_id[UNIQUE_ID_LEN];
+
+       h = kzalloc(sizeof(*h) , GFP_KERNEL);
+       if (!h)
+               return ERR_PTR(-ENOMEM);
+       h->lun = UNINITIALIZED_LUN;
+       h->state = RDAC_STATE_ACTIVE;
+
+       err = get_lun_info(sdev, h, array_name, array_id);
+       if (err != SCSI_DH_OK)
+               goto failed;
+
+       err = initialize_controller(sdev, h, array_name, array_id);
+       if (err != SCSI_DH_OK)
+               goto failed;
+
+       err = check_ownership(sdev, h);
+       if (err != SCSI_DH_OK)
+               goto clean_ctlr;
+
+       err = set_mode_select(sdev, h);
+       if (err != SCSI_DH_OK)
+               goto clean_ctlr;
+
+       sdev_printk(KERN_NOTICE, sdev,
+                   "%s: LUN %d (%s) (%s)\n",
+                   RDAC_NAME, h->lun, mode[(int)h->mode],
+                   lun_state[(int)h->lun_state]);
+
+       return &h->dh_data;
+
+clean_ctlr:
+       spin_lock(&list_lock);
+       kref_put(&h->ctlr->kref, release_controller);
+       spin_unlock(&list_lock);
+
+failed:
+       kfree(h);
+       return ERR_PTR(-EINVAL);
+}
+
+static void rdac_bus_detach( struct scsi_device *sdev )
+{
+       struct rdac_dh_data *h = get_rdac_data(sdev);
+
+       if (h->ctlr && h->ctlr->ms_queued)
+               flush_workqueue(kmpath_rdacd);
+
+       spin_lock(&list_lock);
+       if (h->ctlr)
+               kref_put(&h->ctlr->kref, release_controller);
+       spin_unlock(&list_lock);
+       kfree(h);
+}
+
+static struct scsi_device_handler rdac_dh = {
+       .name = RDAC_NAME,
+       .module = THIS_MODULE,
+       .prep_fn = rdac_prep_fn,
+       .check_sense = rdac_check_sense,
+       .attach = rdac_bus_attach,
+       .detach = rdac_bus_detach,
+       .activate = rdac_activate,
+       .match = rdac_match,
+};
+
+static int __init rdac_init(void)
+{
+       int r;
+
+       r = scsi_register_device_handler(&rdac_dh);
+       if (r != 0) {
+               printk(KERN_ERR "Failed to register scsi device handler.");
+               goto done;
+       }
+
+       /*
+        * Create workqueue to handle mode selects for rdac
+        */
+       kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
+       if (!kmpath_rdacd) {
+               scsi_unregister_device_handler(&rdac_dh);
+               printk(KERN_ERR "kmpath_rdacd creation failed.\n");
+
+               r = -EINVAL;
+       }
+done:
+       return r;
+}
+
+static void __exit rdac_exit(void)
+{
+       destroy_workqueue(kmpath_rdacd);
+       scsi_unregister_device_handler(&rdac_dh);
+}
+
+module_init(rdac_init);
+module_exit(rdac_exit);
+
+MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
+MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
+MODULE_VERSION("01.00.0000.0000");
+MODULE_LICENSE("GPL");