>From 023f27d3d6fcc9048754d879fe5e7d63402a5b16 Mon Sep 17 00:00:00 2001 From: Tejun Heo <t...@kernel.org> Date: Wed, 19 Dec 2012 11:24:06 -0800
42f8570f43 ("workqueue: use new hashtable implementation") incorrectly made busy workers hashed by the pointer value of worker instead of work. This broke find_worker_executing_work() which in turn broke a lot of fundamental operations of workqueue - non-reentrancy and flushing among others. The flush malfunction triggered warning in disk event code in Fengguang's automated test. write_dev_root_ (3265) used greatest stack depth: 2704 bytes left ------------[ cut here ]------------ WARNING: at /c/kernel-tests/src/stable/block/genhd.c:1574 disk_clear_events+0x\ cf/0x108() Hardware name: Bochs Modules linked in: Pid: 3328, comm: ata_id Not tainted 3.7.0-01930-gbff6343 #1167 Call Trace: [<ffffffff810997c4>] warn_slowpath_common+0x83/0x9c [<ffffffff810997f7>] warn_slowpath_null+0x1a/0x1c [<ffffffff816aea77>] disk_clear_events+0xcf/0x108 [<ffffffff811bd8be>] check_disk_change+0x27/0x59 [<ffffffff822e48e2>] cdrom_open+0x49/0x68b [<ffffffff81ab0291>] idecd_open+0x88/0xb7 [<ffffffff811be58f>] __blkdev_get+0x102/0x3ec [<ffffffff811bea08>] blkdev_get+0x18f/0x30f [<ffffffff811bebfd>] blkdev_open+0x75/0x80 [<ffffffff8118f510>] do_dentry_open+0x1ea/0x295 [<ffffffff8118f5f0>] finish_open+0x35/0x41 [<ffffffff8119c720>] do_last+0x878/0xa25 [<ffffffff8119c993>] path_openat+0xc6/0x333 [<ffffffff8119cf37>] do_filp_open+0x38/0x86 [<ffffffff81190170>] do_sys_open+0x6c/0xf9 [<ffffffff8119021e>] sys_open+0x21/0x23 [<ffffffff82c1c3d9>] system_call_fastpath+0x16/0x1b Signed-off-by: Tejun Heo <t...@kernel.org> Reported-by: Fengguang Wu <fengguang...@intel.com> Cc: Sasha Levin <sasha.le...@oracle.com> --- Sorry that I didn't spot this earlier. Fix applied to wq/for-3.9. Thanks a lot Fengguang. You're awesome! kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index d24a411..7967f34 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2172,7 +2172,7 @@ __acquires(&gcwq->lock) /* claim and dequeue */ debug_work_deactivate(work); - hash_add(gcwq->busy_hash, &worker->hentry, (unsigned long)worker); + hash_add(gcwq->busy_hash, &worker->hentry, (unsigned long)work); worker->current_work = work; worker->current_func = work->func; worker->current_cwq = cwq; -- 1.8.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/