On Mon, May 08, 2017 at 07:24:57PM +0800, Ming Lei wrote: > If hw queue is stopped, the following hang can be triggered > when doing pci reset/remove and running heavy I/O load > meantime. > > This patch fixes the issue by calling nvme_uninit_ctrl() > just after nvme_dev_disable(dev, true) in nvme_remove(). > > [ 492.232593] INFO: task nvme-test:5939 blocked for more than 120 seconds. > [ 492.240081] Not tainted 4.11.0.nvme_v4.11_debug_hang+ #3 > [ 492.246600] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [ 492.255346] nvme-test D 0 5939 5938 0x00000080 > [ 492.261475] Call Trace: > [ 492.264215] __schedule+0x289/0x8f0 > [ 492.268105] ? write_cache_pages+0x14c/0x510 > [ 492.272873] schedule+0x36/0x80 > [ 492.276381] io_schedule+0x16/0x40 > [ 492.280181] wait_on_page_bit_common+0x137/0x220 > [ 492.285336] ? page_cache_tree_insert+0x120/0x120 > [ 492.290589] __filemap_fdatawait_range+0x128/0x1a0 > [ 492.295941] filemap_fdatawait_range+0x14/0x30 > [ 492.300902] filemap_fdatawait+0x23/0x30 > [ 492.305282] filemap_write_and_wait+0x4c/0x80 > [ 492.310151] __sync_blockdev+0x1f/0x40 > [ 492.314336] fsync_bdev+0x44/0x50 > [ 492.318039] invalidate_partition+0x24/0x50 > [ 492.322710] del_gendisk+0xcd/0x2e0 > [ 492.326608] nvme_ns_remove+0x105/0x130 [nvme_core] > [ 492.332054] nvme_remove_namespaces+0x32/0x50 [nvme_core] > [ 492.338082] nvme_uninit_ctrl+0x2d/0xa0 [nvme_core] > [ 492.343519] nvme_remove+0x5d/0x170 [nvme] > [ 492.348096] pci_device_remove+0x39/0xc0 > [ 492.352477] device_release_driver_internal+0x141/0x1f0 > [ 492.358311] device_release_driver+0x12/0x20 > [ 492.363072] pci_stop_bus_device+0x8c/0xa0 > [ 492.367646] pci_stop_and_remove_bus_device_locked+0x1a/0x30 > [ 492.373965] remove_store+0x7c/0x90 > [ 492.377852] dev_attr_store+0x18/0x30 > [ 492.381941] sysfs_kf_write+0x3a/0x50 > [ 492.386028] kernfs_fop_write+0xff/0x180 > [ 492.390409] __vfs_write+0x37/0x160 > [ 492.394304] ? selinux_file_permission+0xe5/0x120 > [ 492.399556] ? security_file_permission+0x3b/0xc0 > [ 492.404807] vfs_write+0xb2/0x1b0 > [ 492.408508] ? syscall_trace_enter+0x1d0/0x2b0 > [ 492.413462] SyS_write+0x55/0xc0 > [ 492.417064] do_syscall_64+0x67/0x180 > [ 492.421155] entry_SYSCALL64_slow_path+0x25/0x25 > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> > --- > drivers/nvme/host/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index c8541c3dcd19..ebe13e157c00 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -2185,8 +2185,8 @@ static void nvme_remove(struct pci_dev *pdev) > } > > flush_work(&dev->reset_work); > - nvme_uninit_ctrl(&dev->ctrl); > nvme_dev_disable(dev, true); > + nvme_uninit_ctrl(&dev->ctrl); > nvme_dev_remove_admin(dev); > nvme_free_queues(dev, 0); > nvme_release_cmb(dev); This patch should be wrong, and looks the correct fix should be flushing 'dev->remove_work' before calling nvme_uninit_ctrl(). But it might cause deadloack by calling flush_work(&dev->remove_work) here simply. Thanks, Ming