From: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx> [ Upstream commit 6b40bec3b13278d21fa6c1ae7a0bdf2e550eed5f ] Don't call quiesce(1) and quiesce(0) if array is already suspended, otherwise in level_store, the array is writable after mddev_detach in below part though the intention is to make array writable after resume. mddev_suspend(mddev); mddev_detach(mddev); ... mddev_resume(mddev); And it also causes calltrace as follows in [1]. [48005.653834] WARNING: CPU: 1 PID: 45380 at kernel/kthread.c:510 kthread_park+0x77/0x90 [...] [48005.653976] CPU: 1 PID: 45380 Comm: mdadm Tainted: G OE 5.4.10-arch1-1 #1 [48005.653979] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4105-ITX, BIOS P1.40 08/06/2018 [48005.653984] RIP: 0010:kthread_park+0x77/0x90 [48005.654015] Call Trace: [48005.654039] r5l_quiesce+0x3c/0x70 [raid456] [48005.654052] raid5_quiesce+0x228/0x2e0 [raid456] [48005.654073] mddev_detach+0x30/0x70 [md_mod] [48005.654090] level_store+0x202/0x670 [md_mod] [48005.654099] ? security_capable+0x40/0x60 [48005.654114] md_attr_store+0x7b/0xc0 [md_mod] [48005.654123] kernfs_fop_write+0xce/0x1b0 [48005.654132] vfs_write+0xb6/0x1a0 [48005.654138] ksys_write+0x67/0xe0 [48005.654146] do_syscall_64+0x4e/0x140 [48005.654155] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [48005.654161] RIP: 0033:0x7fa0c8737497 [1]: https://bugzilla.kernel.org/show_bug.cgi?id=206161 Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxxxxxxxx> Signed-off-by: Song Liu <songliubraving@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 4e7c9f398bc66..6b69a12ca2d80 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6040,7 +6040,7 @@ EXPORT_SYMBOL_GPL(md_stop_writes); static void mddev_detach(struct mddev *mddev) { md_bitmap_wait_behind_writes(mddev); - if (mddev->pers && mddev->pers->quiesce) { + if (mddev->pers && mddev->pers->quiesce && !mddev->suspended) { mddev->pers->quiesce(mddev, 1); mddev->pers->quiesce(mddev, 0); } -- 2.20.1
