From eac7cc52c6b410e542af431b2ee93f3d7dbfb6af Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Tue, 6 Nov 2012 11:47:13 +0100 Subject: [PATCH] floppy: destroy floppy workqueue before cleaning up the queue We need to first destroy the floppy_wq workqueue before cleaning up the queue. Otherwise we might race with still pending work with the workqueue, but all the block queue already gone. This might lead to various oopses, such as CPU 0 Pid: 6, comm: kworker/u:0 Not tainted 3.7.0-rc4 #1 Bochs Bochs RIP: 0010:[] [] blk_peek_request+0xd5/0x1c0 RSP: 0000:ffff88000dc7dd88 EFLAGS: 00010092 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88000f602688 RSI: ffffffff81fd95d8 RDI: 6b6b6b6b6b6b6b6b RBP: ffff88000dc7dd98 R08: ffffffff81fd95c8 R09: 0000000000000000 R10: ffffffff81fd9480 R11: 0000000000000001 R12: 6b6b6b6b6b6b6b6b R13: ffff88000dc7dfd8 R14: ffff88000dc7dfd8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001e11000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kworker/u:0 (pid: 6, threadinfo ffff88000dc7c000, task ffff88000dc5ecc0) Stack: 0000000000000000 0000000000000000 ffff88000dc7ddb8 ffffffff8134efee ffff88000dc7ddb8 0000000000000000 ffff88000dc7dde8 ffffffff814aef3c ffffffff81e75d80 ffff88000dc0c640 ffff88000fbfb000 ffffffff814aed90 Call Trace: [] blk_fetch_request+0xe/0x30 [] redo_fd_request+0x1ac/0x400 [] ? start_motor+0x130/0x130 [] process_one_work+0x136/0x450 [] ? manage_workers+0x205/0x2e0 [] worker_thread+0x14d/0x420 [] ? rescuer_thread+0x1a0/0x1a0 [] kthread+0xba/0xc0 [] ? __kthread_parkme+0x80/0x80 [] ret_from_fork+0x7a/0xb0 [] ? __kthread_parkme+0x80/0x80 Code: 0f 84 c0 00 00 00 83 f8 01 0f 85 e2 00 00 00 81 4b 40 00 00 80 00 48 89 df e8 58 f8 ff ff be fb ff ff ff fe ff ff <49> 8b 1c 24 49 39 dc 0f 85 2e ff ff ff 41 0f b6 84 24 28 04 00 RIP [] blk_peek_request+0xd5/0x1c0 RSP Reported-by: Fengguang Wu Tested-by: Fengguang Wu Signed-off-by: Jiri Kosina Signed-off-by: Jens Axboe --- drivers/block/floppy.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 1c49d7173966..2ddd64a9ffde 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4330,6 +4330,7 @@ static int __init do_floppy_init(void) out_unreg_blkdev: unregister_blkdev(FLOPPY_MAJOR, "fd"); out_put_disk: + destroy_workqueue(floppy_wq); for (drive = 0; drive < N_DRIVE; drive++) { if (!disks[drive]) break; @@ -4340,7 +4341,6 @@ static int __init do_floppy_init(void) } put_disk(disks[drive]); } - destroy_workqueue(floppy_wq); return err; } @@ -4555,6 +4555,8 @@ static void __exit floppy_module_exit(void) unregister_blkdev(FLOPPY_MAJOR, "fd"); platform_driver_unregister(&floppy_driver); + destroy_workqueue(floppy_wq); + for (drive = 0; drive < N_DRIVE; drive++) { del_timer_sync(&motor_off_timer[drive]); @@ -4578,7 +4580,6 @@ static void __exit floppy_module_exit(void) cancel_delayed_work_sync(&fd_timeout); cancel_delayed_work_sync(&fd_timer); - destroy_workqueue(floppy_wq); if (atomic_read(&usage_count)) floppy_release_irq_and_dma(); -- GitLab