Hi, On 12/13/2013 09:03 PM, James Bottomley wrote: <snip>
Actually, I think I have this figured out. There's a thinko in one of the scsi_target_reap() cases. The original (and still existing) problem with targets is that nothing creates them and nothing destroys them, so, while we could rely on the refcounting of the device model to preserve the actual target object, we had no idea when to remove it from visibility. That was the job of the reap reference, to track visibility. It looks like the reap on device last put is occurring too late. I think we should reap immediately after doing the sdev device_del, so does this fix the warn on? (I'm not sure because no-one has actually posted a backtrace, but it sounds like this is the problem). James --- diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 8ff62c2..98d4eb3 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -399,8 +399,6 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) /* NULL queue means the device can't be used */ sdev->request_queue = NULL; - scsi_target_reap(scsi_target(sdev)); - kfree(sdev->inquiry); kfree(sdev); @@ -1044,6 +1042,8 @@ void __scsi_remove_device(struct scsi_device *sdev) } else put_device(&sdev->sdev_dev); + scsi_target_reap(scsi_target(sdev)); + /* * Stop accepting new requests and wait until all queuecommand() and * scsi_run_queue() invocations have finished before tearing down the
I've given this patch a try and it fixes the blk-tag.c: 89 BUG() I was seeing. As for the other patch you (James) have send for that problem: diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 8ff62c2..98d4eb3 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -399,8 +399,6 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) /* NULL queue means the device can't be used */ sdev->request_queue = NULL; - scsi_target_reap(scsi_target(sdev)); - kfree(sdev->inquiry); kfree(sdev); @@ -1044,6 +1042,8 @@ void __scsi_remove_device(struct scsi_device *sdev) } else put_device(&sdev->sdev_dev); + scsi_target_reap(scsi_target(sdev)); + /* * Stop accepting new requests and wait until all queuecommand() and * scsi_run_queue() invocations have finished before tearing down the That too fixes the blk-tag.c: 89 BUG() I was seeing. Either patch by itself seems to be enough to fix this issue for me. Thanks & Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
