3 files changed, 111 insertions, 2 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index f15b17708537..4e5441baa49d 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -51,6 +51,7 @@
 #include <scsi/scsi_ioctl.h>
 #include <linux/cdrom.h>
 #include <linux/scatterlist.h>
+#include <linux/kthread.h>
 
 #define CCISS_DRIVER_VERSION(maj,min,submin) ((maj<<16)|(min<<8)|(submin))
 #define DRIVER_NAME "HP CISS Driver (v 3.6.20)"
@@ -186,6 +187,8 @@ static int sendcmd_withirq(__u8 cmd, int ctlr, void *buff, size_t size,
                            __u8 page_code, int cmd_type);
 
 static void fail_all_cmds(unsigned long ctlr);
+static int scan_thread(void *data);
+static int check_for_unit_attention(ctlr_info_t *h, CommandList_struct *c);
 
 #ifdef CONFIG_PROC_FS
 static void cciss_procinit(int i);
@@ -735,6 +738,12 @@ static int cciss_getgeo(struct block_device *bdev, struct hd_geometry *geo)
         return 0;
 }
 
+static void check_ioctl_unit_attention(ctlr_info_t *host, CommandList_struct *c)
+{
+        if (c->err_info->CommandStatus == CMD_TARGET_STATUS &&
+                        c->err_info->ScsiStatus != SAM_STAT_CHECK_CONDITION)
+                (void)check_for_unit_attention(host, c);
+}
 /*
  * ioctl
  */
@@ -1029,6 +1038,8 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
                                          iocommand.buf_size,
                                          PCI_DMA_BIDIRECTIONAL);
 
+                        check_ioctl_unit_attention(host, c);
+
                         /* Copy the error information out */
                         iocommand.error_info = *(c->err_info);
                         if (copy_to_user
@@ -1180,6 +1191,7 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
                                         (dma_addr_t) temp64.val, buff_size[i],
                                         PCI_DMA_BIDIRECTIONAL);
                         }
+                        check_ioctl_unit_attention(host, c);
                         /* Copy the error information out */
                         ioc->error_info = *(c->err_info);
                         if (copy_to_user(argp, ioc, sizeof(*ioc))) {
@@ -2593,12 +2605,14 @@ static inline unsigned int make_status_bytes(unsigned int scsi_status_byte,
                 ((driver_byte & 0xff) << 24);
 }
 
-static inline int evaluate_target_status(CommandList_struct *cmd)
+static inline int evaluate_target_status(ctlr_info_t *h,
+                        CommandList_struct *cmd, int *retry_cmd)
 {
         unsigned char sense_key;
         unsigned char status_byte, msg_byte, host_byte, driver_byte;
         int error_value;
 
+        *retry_cmd = 0;
         /* If we get in here, it means we got "target status", that is, scsi status */
         status_byte = cmd->err_info->ScsiStatus;
         driver_byte = DRIVER_OK;
@@ -2626,6 +2640,11 @@ static inline int evaluate_target_status(CommandList_struct *cmd)
         if (((sense_key == 0x0) || (sense_key == 0x1)) && !blk_pc_request(cmd->rq))
                 error_value = 0;
 
+        if (check_for_unit_attention(h, cmd)) {
+                *retry_cmd = !blk_pc_request(cmd->rq);
+                return 0;
+        }
+
         if (!blk_pc_request(cmd->rq)) { /* Not SG_IO or similar? */
                 if (error_value != 0)
                         printk(KERN_WARNING "cciss: cmd %p has CHECK CONDITION"
@@ -2665,7 +2684,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 
         switch (cmd->err_info->CommandStatus) {
         case CMD_TARGET_STATUS:
-                rq->errors = evaluate_target_status(cmd);
+                rq->errors = evaluate_target_status(h, cmd, &retry_cmd);
                 break;
         case CMD_DATA_UNDERRUN:
                 if (blk_fs_request(cmd->rq)) {
@@ -3016,6 +3035,63 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
+static int scan_thread(void *data)
+{
+        ctlr_info_t *h = data;
+        int rc;
+        DECLARE_COMPLETION_ONSTACK(wait);
+        h->rescan_wait = &wait;
+
+        for (;;) {
+                rc = wait_for_completion_interruptible(&wait);
+                if (kthread_should_stop())
+                        break;
+                if (!rc)
+                        rebuild_lun_table(h, 0);
+        }
+        return 0;
+}
+
+static int check_for_unit_attention(ctlr_info_t *h, CommandList_struct *c)
+{
+        if (c->err_info->SenseInfo[2] != UNIT_ATTENTION)
+                return 0;
+
+        switch (c->err_info->SenseInfo[12]) {
+        case STATE_CHANGED:
+                printk(KERN_WARNING "cciss%d: a state change "
+                        "detected, command retried\n", h->ctlr);
+                return 1;
+        break;
+        case LUN_FAILED:
+                printk(KERN_WARNING "cciss%d: LUN failure "
+                        "detected, action required\n", h->ctlr);
+                return 1;
+        break;
+        case REPORT_LUNS_CHANGED:
+                printk(KERN_WARNING "cciss%d: report LUN data "
+                        "changed\n", h->ctlr);
+                if (h->rescan_wait)
+                        complete(h->rescan_wait);
+                return 1;
+        break;
+        case POWER_OR_RESET:
+                printk(KERN_WARNING "cciss%d: a power on "
+                        "or device reset detected\n", h->ctlr);
+                return 1;
+        break;
+        case UNIT_ATTENTION_CLEARED:
+                printk(KERN_WARNING "cciss%d: unit attention "
+                    "cleared by another initiator\n", h->ctlr);
+                return 1;
+        break;
+        default:
+                printk(KERN_WARNING "cciss%d: unknown "
+                        "unit attention detected\n", h->ctlr);
+                                return 1;
+        }
+}
+
 /*
  *  We cannot read the structure directly, for portability we must use
  *   the io functions.
@@ -3761,6 +3837,11 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
         hba[i]->busy_initializing = 0;
 
         rebuild_lun_table(hba[i], 1);
+        hba[i]->cciss_scan_thread = kthread_run(scan_thread, hba[i],
+                                "cciss_scan%02d", i);
+        if (IS_ERR(hba[i]->cciss_scan_thread))
+                return PTR_ERR(hba[i]->cciss_scan_thread);
+
         return 1;
 
 clean4:
@@ -3836,6 +3917,7 @@ static void __devexit cciss_remove_one(struct pci_dev *pdev)
                 printk(KERN_ERR "cciss: Unable to remove device \n");
                 return;
         }
+
         tmp_ptr = pci_get_drvdata(pdev);
         i = tmp_ptr->ctlr;
         if (hba[i] == NULL) {
@@ -3844,6 +3926,8 @@ static void __devexit cciss_remove_one(struct pci_dev *pdev)
                 return;
         }
 
+        kthread_stop(hba[i]->cciss_scan_thread);
+
         remove_proc_entry(hba[i]->devname, proc_cciss);
         unregister_blkdev(hba[i]->major, hba[i]->devname);
 
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 15e2b84734e3..703e08038fb9 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -121,6 +121,8 @@ struct ctlr_info
         struct sendcmd_reject_list scsi_rejects;
 #endif
         unsigned char alive;
+        struct completion *rescan_wait;
+        struct task_struct *cciss_scan_thread;
 };
 
 /*  Defining the diffent access_menthods */
diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h
index 24e22dea1a99..40b1b92dae7f 100644
--- a/drivers/block/cciss_cmd.h
+++ b/drivers/block/cciss_cmd.h
@@ -25,6 +25,29 @@
 #define CMD_TIMEOUT             0x000B
 #define CMD_UNABORTABLE         0x000C
 
+/* Unit Attentions ASC's as defined for the MSA2012sa */
+#define POWER_OR_RESET                  0x29
+#define STATE_CHANGED                   0x2a
+#define UNIT_ATTENTION_CLEARED          0x2f
+#define LUN_FAILED                      0x3e
+#define REPORT_LUNS_CHANGED             0x3f
+
+/* Unit Attentions ASCQ's as defined for the MSA2012sa */
+
+        /* These ASCQ's defined for ASC = POWER_OR_RESET */
+#define POWER_ON_RESET                  0x00
+#define POWER_ON_REBOOT                 0x01
+#define SCSI_BUS_RESET                  0x02
+#define MSA_TARGET_RESET                0x03
+#define CONTROLLER_FAILOVER             0x04
+#define TRANSCEIVER_SE                  0x05
+#define TRANSCEIVER_LVD                 0x06
+
+        /* These ASCQ's defined for ASC = STATE_CHANGED */
+#define RESERVATION_PREEMPTED           0x03
+#define ASYM_ACCESS_CHANGED             0x06
+#define LUN_CAPACITY_CHANGED            0x09
+
 //transfer direction
 #define XFER_NONE               0x00
 #define XFER_WRITE              0x01