target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export

The following fixes a divide by zero OOPs with TYPE_TAPE
due to pscsi_tape_read_blocksize() failing causing a zero
sd->sector_size being propigated up via dev_attrib.hw_block_size.

It also fixes another long-standing bug where TYPE_TAPE and
TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(),
which does not call scsi_device_get() to take the device
reference.  Instead, rename pscsi_create_type_rom() to
pscsi_create_type_nondisk() and use it for all cases.

Finally, also drop a dump_stack() in pscsi_get_blocks() for
non TYPE_DISK, which in modern target-core can get invoked
via target_sense_desc_format() during CHECK_CONDITION.

Reported-by: Malcolm Haak <insanemal@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 12 insertions, 35 deletions

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index a8f8e53f2f57..44d92f23a3f0 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -154,7 +154,7 @@ static void pscsi_tape_read_blocksize(struct se_device *dev,
 
         buf = kzalloc(12, GFP_KERNEL);
         if (!buf)
-                return;
+                goto out_free;
 
         memset(cdb, 0, MAX_COMMAND_SIZE);
         cdb[0] = MODE_SENSE;
@@ -169,9 +169,10 @@ static void pscsi_tape_read_blocksize(struct se_device *dev,
          * If MODE_SENSE still returns zero, set the default value to 1024.
          */
         sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
+out_free:
         if (!sdev->sector_size)
                 sdev->sector_size = 1024;
-out_free:
+
         kfree(buf);
 }
 
@@ -314,9 +315,10 @@ static int pscsi_add_device_to_list(struct se_device *dev,
                                 sd->lun, sd->queue_depth);
         }
 
-        dev->dev_attrib.hw_block_size = sd->sector_size;
+        dev->dev_attrib.hw_block_size =
+                min_not_zero((int)sd->sector_size, 512);
         dev->dev_attrib.hw_max_sectors =
-                min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
+                min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
         dev->dev_attrib.hw_queue_depth = sd->queue_depth;
 
         /*
@@ -339,8 +341,10 @@ static int pscsi_add_device_to_list(struct se_device *dev,
         /*
          * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
          */
-        if (sd->type == TYPE_TAPE)
+        if (sd->type == TYPE_TAPE) {
                 pscsi_tape_read_blocksize(dev, sd);
+                dev->dev_attrib.hw_block_size = sd->sector_size;
+        }
         return 0;
 }
 
@@ -406,7 +410,7 @@ static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
 /*
  * Called with struct Scsi_Host->host_lock called.
  */
-static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
+static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
         __releases(sh->host_lock)
 {
         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
@@ -433,28 +437,6 @@ static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
         return 0;
 }
 
-/*
- * Called with struct Scsi_Host->host_lock called.
- */
-static int pscsi_create_type_other(struct se_device *dev,
-                struct scsi_device *sd)
-        __releases(sh->host_lock)
-{
-        struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
-        struct Scsi_Host *sh = sd->host;
-        int ret;
-
-        spin_unlock_irq(sh->host_lock);
-        ret = pscsi_add_device_to_list(dev, sd);
-        if (ret)
-                return ret;
-
-        pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
-                phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
-                sd->channel, sd->id, sd->lun);
-        return 0;
-}
-
 static int pscsi_configure_device(struct se_device *dev)
 {
         struct se_hba *hba = dev->se_hba;
@@ -542,11 +524,8 @@ static int pscsi_configure_device(struct se_device *dev)
                 case TYPE_DISK:
                         ret = pscsi_create_type_disk(dev, sd);
                         break;
-                case TYPE_ROM:
-                        ret = pscsi_create_type_rom(dev, sd);
-                        break;
                 default:
-                        ret = pscsi_create_type_other(dev, sd);
+                        ret = pscsi_create_type_nondisk(dev, sd);
                         break;
                 }
 
@@ -611,8 +590,7 @@ static void pscsi_free_device(struct se_device *dev)
                 else if (pdv->pdv_lld_host)
                         scsi_host_put(pdv->pdv_lld_host);
 
-                if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
-                        scsi_device_put(sd);
+                scsi_device_put(sd);
 
                 pdv->pdv_sd = NULL;
         }
@@ -1064,7 +1042,6 @@ static sector_t pscsi_get_blocks(struct se_device *dev)
         if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
                 return pdv->pdv_bd->bd_part->nr_sects;
 
-        dump_stack();
         return 0;
 }