[GIT PULL] SCSI fixes for 3.17-rc1

[James Bottomley <James.Bottomley@HansenPartnership.com>]

These are the two bug fixes I mentioned in the final merge window pull.
One is a reversed logic check in the device busy tests which can cause a
nasty hang and another crash seen in the new SCSI pool support if the
use count ever goes to zero.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Guenter Roeck (1):
      fix qemu boot hang problem

Juergen Gross (1):
      save command pool address of Scsi_Host

And the diffstat:

 drivers/scsi/scsi.c     | 12 ++++++++++--
 drivers/scsi/scsi_lib.c |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)

With full diff below.

James

---

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index df33060..d81f3cc 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -377,6 +377,10 @@ scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
 		pool->slab_flags |= SLAB_CACHE_DMA;
 		pool->gfp_mask = __GFP_DMA;
 	}
+
+	if (hostt->cmd_size)
+		hostt->cmd_pool = pool;
+
 	return pool;
 }
 
@@ -421,8 +425,10 @@ out:
 out_free_slab:
 	kmem_cache_destroy(pool->cmd_slab);
 out_free_pool:
-	if (hostt->cmd_size)
+	if (hostt->cmd_size) {
 		scsi_free_host_cmd_pool(pool);
+		hostt->cmd_pool = NULL;
+	}
 	goto out;
 }
 
@@ -444,8 +450,10 @@ static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
 	if (!--pool->users) {
 		kmem_cache_destroy(pool->cmd_slab);
 		kmem_cache_destroy(pool->sense_slab);
-		if (hostt->cmd_size)
+		if (hostt->cmd_size) {
 			scsi_free_host_cmd_pool(pool);
+			hostt->cmd_pool = NULL;
+		}
 	}
 	mutex_unlock(&host_cmd_pool_mutex);
 }
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9c44392..ce62e87 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1774,7 +1774,7 @@ static void scsi_request_fn(struct request_queue *q)
 	blk_requeue_request(q, req);
 	atomic_dec(&sdev->device_busy);
 out_delay:
-	if (atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
+	if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
 		blk_delay_queue(q, SCSI_QUEUE_DELAY);
 }