hpsa: correct handling of HBA device removal

Need to report HBA device removal faster than the
event handler polling interval.

Stop I/O to the removed disk and wait for all
I/O operations to flush before removing the device.

Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 85 insertions, 5 deletions

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 4f8e3285baa9..034624f1ca64 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -294,6 +294,9 @@ static void hpsa_disable_rld_caching(struct ctlr_info *h);
 static inline int hpsa_scsi_do_report_phys_luns(struct ctlr_info *h,
         struct ReportExtendedLUNdata *buf, int bufsize);
 static int hpsa_luns_changed(struct ctlr_info *h);
+static bool hpsa_cmd_dev_match(struct ctlr_info *h, struct CommandList *c,
+                               struct hpsa_scsi_dev_t *dev,
+                               unsigned char *scsi3addr);
 
 static inline struct ctlr_info *sdev_to_hba(struct scsi_device *sdev)
 {
@@ -1745,6 +1748,51 @@ static int hpsa_add_device(struct ctlr_info *h, struct hpsa_scsi_dev_t *device)
         return rc;
 }
 
+static int hpsa_find_outstanding_commands_for_dev(struct ctlr_info *h,
+                                                struct hpsa_scsi_dev_t *dev)
+{
+        int i;
+        int count = 0;
+
+        for (i = 0; i < h->nr_cmds; i++) {
+                struct CommandList *c = h->cmd_pool + i;
+                int refcount = atomic_inc_return(&c->refcount);
+
+                if (refcount > 1 && hpsa_cmd_dev_match(h, c, dev,
+                                dev->scsi3addr)) {
+                        unsigned long flags;
+
+                        spin_lock_irqsave(&h->lock, flags);     /* Implied MB */
+                        if (!hpsa_is_cmd_idle(c))
+                                ++count;
+                        spin_unlock_irqrestore(&h->lock, flags);
+                }
+
+                cmd_free(h, c);
+        }
+
+        return count;
+}
+
+static void hpsa_wait_for_outstanding_commands_for_dev(struct ctlr_info *h,
+                                                struct hpsa_scsi_dev_t *device)
+{
+        int cmds = 0;
+        int waits = 0;
+
+        while (1) {
+                cmds = hpsa_find_outstanding_commands_for_dev(h, device);
+                if (cmds == 0)
+                        break;
+                if (++waits > 20)
+                        break;
+                dev_warn(&h->pdev->dev,
+                        "%s: removing device with %d outstanding commands!\n",
+                        __func__, cmds);
+                msleep(1000);
+        }
+}
+
 static void hpsa_remove_device(struct ctlr_info *h,
                         struct hpsa_scsi_dev_t *device)
 {
@@ -1768,8 +1816,13 @@ static void hpsa_remove_device(struct ctlr_info *h,
                         hpsa_show_dev_msg(KERN_WARNING, h, device,
                                         "didn't find device for removal.");
                 }
-        } else /* HBA */
+        } else { /* HBA */
+
+                device->removed = 1;
+                hpsa_wait_for_outstanding_commands_for_dev(h, device);
+
                 hpsa_remove_sas_device(device);
+        }
 }
 
 static void adjust_hpsa_scsi_table(struct ctlr_info *h,
@@ -2171,7 +2224,8 @@ static void hpsa_unmap_sg_chain_block(struct ctlr_info *h,
 static int handle_ioaccel_mode2_error(struct ctlr_info *h,
                                         struct CommandList *c,
                                         struct scsi_cmnd *cmd,
-                                        struct io_accel2_cmd *c2)
+                                        struct io_accel2_cmd *c2,
+                                        struct hpsa_scsi_dev_t *dev)
 {
         int data_len;
         int retry = 0;
@@ -2235,8 +2289,27 @@ static int handle_ioaccel_mode2_error(struct ctlr_info *h,
                 case IOACCEL2_STATUS_SR_NO_PATH_TO_DEVICE:
                 case IOACCEL2_STATUS_SR_INVALID_DEVICE:
                 case IOACCEL2_STATUS_SR_IOACCEL_DISABLED:
-                        /* We will get an event from ctlr to trigger rescan */
-                        retry = 1;
+                        /*
+                         * Did an HBA disk disappear? We will eventually
+                         * get a state change event from the controller but
+                         * in the meantime, we need to tell the OS that the
+                         * HBA disk is no longer there and stop I/O
+                         * from going down. This allows the potential re-insert
+                         * of the disk to get the same device node.
+                         */
+                        if (dev->physical_device && dev->expose_device) {
+                                cmd->result = DID_NO_CONNECT << 16;
+                                dev->removed = 1;
+                                h->drv_req_rescan = 1;
+                                dev_warn(&h->pdev->dev,
+                                        "%s: device is gone!\n", __func__);
+                        } else
+                                /*
+                                 * Retry by sending down the RAID path.
+                                 * We will get an event from ctlr to
+                                 * trigger rescan regardless.
+                                 */
+                                retry = 1;
                         break;
                 default:
                         retry = 1;
@@ -2368,7 +2441,7 @@ static void process_ioaccel2_completion(struct ctlr_info *h,
                 return hpsa_retry_cmd(h, c);
         }
 
-        if (handle_ioaccel_mode2_error(h, c, cmd, c2))
+        if (handle_ioaccel_mode2_error(h, c, cmd, c2, dev))
                 return hpsa_retry_cmd(h, c);
 
         return hpsa_cmd_free_and_done(h, c, cmd);
@@ -5263,6 +5336,12 @@ static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 
         dev = cmd->device->hostdata;
         if (!dev) {
+                cmd->result = NOT_READY << 16; /* host byte */
+                cmd->scsi_done(cmd);
+                return 0;
+        }
+
+        if (dev->removed) {
                 cmd->result = DID_NO_CONNECT << 16;
                 cmd->scsi_done(cmd);
                 return 0;
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index d06bb7417e36..a1487e67f7a1 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -63,6 +63,7 @@ struct hpsa_scsi_dev_t {
         unsigned char scsi3addr[8];     /* as presented to the HW */
         u8 physical_device : 1;
         u8 expose_device;
+        u8 removed : 1;                 /* device is marked for death */
 #define RAID_CTLR_LUNID "\0\0\0\0\0\0\0\0"
         unsigned char device_id[16];    /* from inquiry pg. 0x83 */
         u64 sas_address;