[PATCH v3] USB: usb-skeleton.c: fix compilation error and restored kref_put on fail in skel_open

From: Constantine Shulyupin
Date: Wed Oct 10 2012 - 10:14:06 EST


From: Constantine Shulyupin <const@xxxxxxxxxxxxx>

Fixing compilaton error.
Incrementing usage counter only on successful execution of skel_open.
Removing redundant locking

Some last changes in function skel_open and finally commit
52a7499 Revert "USB: usb-skeleton.c: fix open/disconnect race"
introduced a bug in function skel_open, which this patch fixes.

--

Changelog:
Changes since v2:
- refactoring
- Removing redundant mutex synchronization.

Changes since v1:
- Fixed accordingly feedback of Oliver Neukum oneukum@xxxxxxx: also need to drop the lock.

Signed-off-by: Constantine Shulyupin <const@xxxxxxxxxxxxx>
---
drivers/usb/usb-skeleton.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 0616f23..ce31017 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -105,20 +105,15 @@ static int skel_open(struct inode *inode, struct file *file)
goto exit;
}

- /* increment our usage count for the device */
- kref_get(&dev->kref);
-
- /* lock the device to allow correctly handling errors
- * in resumption */
- mutex_lock(&dev->io_mutex);
-
retval = usb_autopm_get_interface(interface);
if (retval)
- goto out_err;
+ goto exit;
+
+ /* increment our usage count for the device */
+ kref_get(&dev->kref);

/* save our object in the file's private structure */
file->private_data = dev;
- mutex_unlock(&dev->io_mutex);

exit:
return retval;
--
1.7.9.5

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