Commits
Tejun Heo committed 4eabc941259
block: don't kick empty queue in blk_drain_queue() 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> Signed-off-by: Jens Axboe <axboe@kernel.dk>