[GIT PULL] SCSI fixes for 4.2-rc2

James Bottomley
2015-07-19T09:37:53Z

Two fairly simple fixes: one is a change that causes us to have a very
low queue depth leading to performance issues and the other is a null
deref occasionally in tapes thanks to use after put.

The patch is available here:

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

The short changelog is:

Jens Axboe (1):
scsi: fix host max depth checking for the 'queue_depth' sysfs interface

Seymour, Shane M (1):
st: null pointer dereference panic caused by use after kref_put by st_open

And the diffstat:

drivers/scsi/scsi_sysfs.c | 2 +-
drivers/scsi/st.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

With full diffs below.

James

---

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 1ac38e7..9ad4116 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -859,7 +859,7 @@ sdev_store_queue_depth(struct device *dev, struct device_attribute *attr,

depth = simple_strtoul(buf, NULL, 0);

- if (depth < 1 || depth > sht->can_queue)
+ if (depth < 1 || depth > sdev->host->can_queue)
return -EINVAL;

retval = sht->change_queue_depth(sdev, depth);
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 3f25b8f..871f355 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -1329,9 +1329,9 @@ static int st_open(struct inode *inode, struct file *filp)
spin_lock(&st_use_lock);
STp->in_use = 0;
spin_unlock(&st_use_lock);
- scsi_tape_put(STp);
if (resumed)
scsi_autopm_put_device(STp->device);
+ scsi_tape_put(STp);
return retval;

}