[SCSI] scsi_dh: Update hp_sw hardware handler
authorHannes Reinecke <hare@suse.de>
Thu, 17 Jul 2008 23:53:09 +0000 (16:53 -0700)
committerJames Bottomley <James.Bottomley@HansenPartnership.com>
Sat, 26 Jul 2008 19:14:52 +0000 (15:14 -0400)
This patch updates the hp_sw device handler to properly
check the return codes etc.
And adds the 'correct' machine definitions.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
drivers/scsi/device_handler/scsi_dh_hp_sw.c

index 78259bc..9c7a1f8 100644 (file)
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
  * Copyright (C) 2006 Mike Christie
+ * Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
  *
  * 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
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_dh.h>
 
-#define HP_SW_NAME     "hp_sw"
+#define HP_SW_NAME                     "hp_sw"
 
-#define HP_SW_TIMEOUT (60 * HZ)
-#define HP_SW_RETRIES 3
+#define HP_SW_TIMEOUT                  (60 * HZ)
+#define HP_SW_RETRIES                  3
+
+#define HP_SW_PATH_UNINITIALIZED       -1
+#define HP_SW_PATH_ACTIVE              0
+#define HP_SW_PATH_PASSIVE             1
 
 struct hp_sw_dh_data {
        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+       int path_state;
        int retries;
 };
 
@@ -42,51 +48,161 @@ static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
        return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
 }
 
-static int hp_sw_done(struct scsi_device *sdev)
+/*
+ * tur_done - Handle TEST UNIT READY return status
+ * @sdev: sdev the command has been sent to
+ * @errors: blk error code
+ *
+ * Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
+ */
+static int tur_done(struct scsi_device *sdev, unsigned char *sense)
 {
-       struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
        struct scsi_sense_hdr sshdr;
-       int rc;
-
-       sdev_printk(KERN_INFO, sdev, "hp_sw_done\n");
+       int ret;
 
-       rc = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
-       if (!rc)
+       ret = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
+       if (!ret) {
+               sdev_printk(KERN_WARNING, sdev,
+                           "%s: sending tur failed, no sense available\n",
+                           HP_SW_NAME);
+               ret = SCSI_DH_IO;
                goto done;
+       }
        switch (sshdr.sense_key) {
+       case UNIT_ATTENTION:
+               ret = SCSI_DH_IMM_RETRY;
+               break;
        case NOT_READY:
-               if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
-                       rc = SCSI_DH_RETRY;
-                       h->retries++;
+               if ((sshdr.asc == 0x04) && (sshdr.ascq == 2)) {
+                       /*
+                        * LUN not ready - Initialization command required
+                        *
+                        * This is the passive path
+                        */
+                       ret = SCSI_DH_DEV_OFFLINED;
                        break;
                }
-               /* fall through */
+               /* Fallthrough */
        default:
-               h->retries++;
-               rc = SCSI_DH_IMM_RETRY;
+               sdev_printk(KERN_WARNING, sdev,
+                          "%s: sending tur failed, sense %x/%x/%x\n",
+                          HP_SW_NAME, sshdr.sense_key, sshdr.asc,
+                          sshdr.ascq);
+               break;
        }
 
 done:
-       if (rc == SCSI_DH_OK || rc == SCSI_DH_IO)
-               h->retries = 0;
-       else if (h->retries > HP_SW_RETRIES) {
-               h->retries = 0;
+       return ret;
+}
+
+/*
+ * hp_sw_tur - Send TEST UNIT READY
+ * @sdev: sdev command should be sent to
+ *
+ * Use the TEST UNIT READY command to determine
+ * the path state.
+ */
+static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
+{
+       struct request *req;
+       int ret;
+
+       req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
+       if (!req)
+               return SCSI_DH_RES_TEMP_UNAVAIL;
+
+       req->cmd_type = REQ_TYPE_BLOCK_PC;
+       req->cmd_flags |= REQ_FAILFAST;
+       req->cmd_len = COMMAND_SIZE(TEST_UNIT_READY);
+       memset(req->cmd, 0, MAX_COMMAND_SIZE);
+       req->cmd[0] = TEST_UNIT_READY;
+       req->timeout = HP_SW_TIMEOUT;
+       req->sense = h->sense;
+       memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
+       req->sense_len = 0;
+
+retry:
+       ret = blk_execute_rq(req->q, NULL, req, 1);
+       if (ret == -EIO) {
+               if (req->sense_len > 0) {
+                       ret = tur_done(sdev, h->sense);
+               } else {
+                       sdev_printk(KERN_WARNING, sdev,
+                                   "%s: sending tur failed with %x\n",
+                                   HP_SW_NAME, req->errors);
+                       ret = SCSI_DH_IO;
+               }
+       } else {
+               h->path_state = HP_SW_PATH_ACTIVE;
+               ret = SCSI_DH_OK;
+       }
+       if (ret == SCSI_DH_IMM_RETRY)
+               goto retry;
+       if (ret == SCSI_DH_DEV_OFFLINED) {
+               h->path_state = HP_SW_PATH_PASSIVE;
+               ret = SCSI_DH_OK;
+       }
+
+       blk_put_request(req);
+
+       return ret;
+}
+
+/*
+ * start_done - Handle START STOP UNIT return status
+ * @sdev: sdev the command has been sent to
+ * @errors: blk error code
+ */
+static int start_done(struct scsi_device *sdev, unsigned char *sense)
+{
+       struct scsi_sense_hdr sshdr;
+       int rc;
+
+       rc = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
+       if (!rc) {
+               sdev_printk(KERN_WARNING, sdev,
+                           "%s: sending start_stop_unit failed, "
+                           "no sense available\n",
+                           HP_SW_NAME);
+               return SCSI_DH_IO;
+       }
+       switch (sshdr.sense_key) {
+       case NOT_READY:
+               if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
+                       /*
+                        * LUN not ready - manual intervention required
+                        *
+                        * Switch-over in progress, retry.
+                        */
+                       rc = SCSI_DH_RETRY;
+                       break;
+               }
+               /* fall through */
+       default:
+               sdev_printk(KERN_WARNING, sdev,
+                          "%s: sending start_stop_unit failed, sense %x/%x/%x\n",
+                          HP_SW_NAME, sshdr.sense_key, sshdr.asc,
+                          sshdr.ascq);
                rc = SCSI_DH_IO;
        }
+
        return rc;
 }
 
-static int hp_sw_activate(struct scsi_device *sdev)
+/*
+ * hp_sw_start_stop - Send START STOP UNIT command
+ * @sdev: sdev command should be sent to
+ *
+ * Sending START STOP UNIT activates the SP.
+ */
+static int hp_sw_start_stop(struct scsi_device *sdev, struct hp_sw_dh_data *h)
 {
-       struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
        struct request *req;
-       int ret = SCSI_DH_RES_TEMP_UNAVAIL;
+       int ret, retry;
 
-       req = blk_get_request(sdev->request_queue, WRITE, GFP_ATOMIC);
+       req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
        if (!req)
-               goto done;
-
-       sdev_printk(KERN_INFO, sdev, "sending START_STOP.");
+               return SCSI_DH_RES_TEMP_UNAVAIL;
 
        req->cmd_type = REQ_TYPE_BLOCK_PC;
        req->cmd_flags |= REQ_FAILFAST;
@@ -98,19 +214,78 @@ static int hp_sw_activate(struct scsi_device *sdev)
        req->sense = h->sense;
        memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
        req->sense_len = 0;
+       retry = h->retries;
 
+retry:
        ret = blk_execute_rq(req->q, NULL, req, 1);
-       if (!ret) /* SUCCESS */
-               ret = hp_sw_done(sdev);
-       else
+       if (ret == -EIO) {
+               if (req->sense_len > 0) {
+                       ret = start_done(sdev, h->sense);
+               } else {
+                       sdev_printk(KERN_WARNING, sdev,
+                                   "%s: sending start_stop_unit failed with %x\n",
+                                   HP_SW_NAME, req->errors);
+                       ret = SCSI_DH_IO;
+               }
+       } else
+               ret = SCSI_DH_OK;
+
+       if (ret == SCSI_DH_RETRY) {
+               if (--retry)
+                       goto retry;
                ret = SCSI_DH_IO;
-done:
+       }
+
+       blk_put_request(req);
+
+       return ret;
+}
+
+static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
+{
+       struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+       int ret = BLKPREP_OK;
+
+       if (h->path_state != HP_SW_PATH_ACTIVE) {
+               ret = BLKPREP_KILL;
+               req->cmd_flags |= REQ_QUIET;
+       }
+       return ret;
+
+}
+
+/*
+ * hp_sw_activate - Activate a path
+ * @sdev: sdev on the path to be activated
+ *
+ * The HP Active/Passive firmware is pretty simple;
+ * the passive path reports NOT READY with sense codes
+ * 0x04/0x02; a START STOP UNIT command will then
+ * activate the passive path (and deactivate the
+ * previously active one).
+ */
+static int hp_sw_activate(struct scsi_device *sdev)
+{
+       int ret = SCSI_DH_OK;
+       struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+
+       ret = hp_sw_tur(sdev, h);
+
+       if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE) {
+               ret = hp_sw_start_stop(sdev, h);
+               if (ret == SCSI_DH_OK)
+                       sdev_printk(KERN_INFO, sdev,
+                                   "%s: activated path\n",
+                                   HP_SW_NAME);
+       }
+
        return ret;
 }
 
 const struct scsi_dh_devlist hp_sw_dh_data_list[] = {
-       {"COMPAQ", "MSA"},
-       {"HP", "HSV"},
+       {"COMPAQ", "MSA1000 VOLUME"},
+       {"COMPAQ", "HSV110"},
+       {"HP", "HSV100"},
        {"DEC", "HSG80"},
        {NULL, NULL},
 };
@@ -125,30 +300,51 @@ static struct scsi_device_handler hp_sw_dh = {
        .attach         = hp_sw_bus_attach,
        .detach         = hp_sw_bus_detach,
        .activate       = hp_sw_activate,
+       .prep_fn        = hp_sw_prep_fn,
 };
 
 static int hp_sw_bus_attach(struct scsi_device *sdev)
 {
        struct scsi_dh_data *scsi_dh_data;
+       struct hp_sw_dh_data *h;
        unsigned long flags;
+       int ret;
 
        scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
                               + sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
        if (!scsi_dh_data) {
-               sdev_printk(KERN_ERR, sdev, "Attach Failed %s.\n",
+               sdev_printk(KERN_ERR, sdev, "%s: Attach Failed\n",
                            HP_SW_NAME);
                return 0;
        }
 
        scsi_dh_data->scsi_dh = &hp_sw_dh;
+       h = (struct hp_sw_dh_data *) scsi_dh_data->buf;
+       h->path_state = HP_SW_PATH_UNINITIALIZED;
+       h->retries = HP_SW_RETRIES;
+
+       ret = hp_sw_tur(sdev, h);
+       if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
+               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);
-       try_module_get(THIS_MODULE);
 
-       sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", HP_SW_NAME);
+       sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
+                   HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
+                   "active":"passive");
 
        return 0;
+
+failed:
+       kfree(scsi_dh_data);
+       sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
+                   HP_SW_NAME);
+       return -EINVAL;
 }
 
 static void hp_sw_bus_detach( struct scsi_device *sdev )
@@ -162,7 +358,7 @@ static void hp_sw_bus_detach( struct scsi_device *sdev )
        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
        module_put(THIS_MODULE);
 
-       sdev_printk(KERN_NOTICE, sdev, "Detached %s\n", HP_SW_NAME);
+       sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", HP_SW_NAME);
 
        kfree(scsi_dh_data);
 }
@@ -180,6 +376,6 @@ static void __exit hp_sw_exit(void)
 module_init(hp_sw_init);
 module_exit(hp_sw_exit);
 
-MODULE_DESCRIPTION("HP MSA 1000");
+MODULE_DESCRIPTION("HP Active/Passive driver");
 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
 MODULE_LICENSE("GPL");