[GIT PULL] SCSI fixes for 3.17-rc1

From: James Bottomley
Date: Tue Aug 19 2014 - 14:54:39 EST


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);
}



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