[PATCH v3] scsi: sg: Avoid race in error handling & drop bogus warn

[Alexander Wetzel]

On 04.04.24 01:24, Bart Van Assche wrote:
> On 4/1/24 12:10 PM, Alexander Wetzel wrote:
>> @@ -301,11 +302,12 @@ sg_open(struct inode *inode, struct file *filp)
>>       /* This driver's module count bumped by fops_get in <linux/fs.h> */
>>       /* Prevent the device driver from vanishing while we sleep */
>> -    retval = scsi_device_get(sdp->device);
>> +    device = sdp->device;
>> +    retval = scsi_device_get(device);
>>       if (retval)
>>           goto sg_put;
> 
> Are all the sdp->device -> device changes essential? Isn't there a
> preference to minimize patches that will end up in the stable trees?
> 

Only the very last change is essential:
-       scsi_device_put(sdp->device);
-       goto sg_put;
+       kref_put(&sdp->d_ref, sg_device_destroy);
+       scsi_device_put(device);
+       return retval;

Not using a (required) local variable and de-referencing it again and 
looks strange for anyone reading the code. While the additional lines in 
the patch are trivial to review...

Alexander