Messages in this thread | | | Date | Thu, 15 Dec 2011 20:01:38 +0100 | From | Jens Axboe <> | Subject | Re: [PATCH 3.2-rc5] block: don't kick empty queue in blk_drain_queue() |
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On 2011-12-15 19:58, Tejun Heo wrote: > While probing, fd sets up queue, probes hardware and tears down the > queue if probing fails. In the process, blk_drain_queue() kicks the > queue which failed to finish initialization and fd is unhappy about > that. > > floppy0: no floppy controllers found > ------------[ cut here ]------------ > WARNING: at drivers/block/floppy.c:2929 do_fd_request+0xbf/0xd0() > Hardware name: To Be Filled By O.E.M. > VFS: do_fd_request called on non-open device > Modules linked in: > Pid: 1, comm: swapper Not tainted 3.2.0-rc4-00077-g5983fe2 #2 > Call Trace: > [<ffffffff81039a6a>] warn_slowpath_common+0x7a/0xb0 > [<ffffffff81039b41>] warn_slowpath_fmt+0x41/0x50 > [<ffffffff813d657f>] do_fd_request+0xbf/0xd0 > [<ffffffff81322b95>] blk_drain_queue+0x65/0x80 > [<ffffffff81322c93>] blk_cleanup_queue+0xe3/0x1a0 > [<ffffffff818a809d>] floppy_init+0xdeb/0xe28 > [<ffffffff818a72b2>] ? daring+0x6b/0x6b > [<ffffffff810002af>] do_one_initcall+0x3f/0x170 > [<ffffffff81884b34>] kernel_init+0x9d/0x11e > [<ffffffff810317c2>] ? schedule_tail+0x22/0xa0 > [<ffffffff815dbb14>] kernel_thread_helper+0x4/0x10 > [<ffffffff81884a97>] ? start_kernel+0x2be/0x2be > [<ffffffff815dbb10>] ? gs_change+0xb/0xb > > Avoid it by making blk_drain_queue() kick queue iff dispatch queue has > something on it. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Reported-by: Ralf Hildebrandt <Ralf.Hildebrandt@charite.de> > Reported-by: Wu Fengguang <fengguang.wu@intel.com> > Tested-by: Sergei Trofimovich <slyich@gmail.com> > --- > block/blk-core.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > diff --git a/block/blk-core.c b/block/blk-core.c > index ea70e6c..e9aa3d5 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -366,7 +366,14 @@ void blk_drain_queue(struct request_queue *q, bool drain_all) > if (drain_all) > blk_throtl_drain(q); > > - __blk_run_queue(q); > + /* > + * This function might be called on a queue which failed > + * driver init after queue creation. Some drivers > + * (e.g. fd) get unhappy in such cases. Kick queue iff > + * dispatch queue has something on it. > + */ > + if (!list_empty(&q->queue_head)) > + __blk_run_queue(q); > > if (drain_all) > nr_rqs = q->rq.count[0] + q->rq.count[1];
Thanks, I'll queue this up. Coincidentally, it also exposed a bug in the fusion-io driver.
-- Jens Axboe
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