Re: [GIT PULL] block fixes for 3.1-rc

From: Linus Torvalds
Date: Tue Sep 27 2011 - 19:53:12 EST


On Wed, Sep 21, 2011 at 5:19 AM, Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> Final round of patches for 3.1.

Apparently better not.

The "block layer oopses on USB device removal" is still there, it seems.

I can even find a patch from it from Alan Stern:

https://lkml.org/lkml/2011/9/18/63

and the reason I found that was that my wife's machine just saw what
looks very much like that bug in elv_put_request().

The call chain on that particular machine was:

- __blk_put_request
blk_put_request
scsi_execute
scsi_execute_req
sd_check_events
disk_events_workfn
process_one_work

in one of the kthread helpers. It sounds like something either
generates disk events after the unplug event (despite a "safely
remove" thing), or doesn't properly wait for the disk events to have
flushed before the elevator is cleared.

The "things go oops at USB removal" reports have been with us for a
*loong* time now. Can we please get this fixed already, and have
somebody really look at it?

And if you can't figure out why it happens, at least apply Alan's
patch (or ack it).

Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/