ee52acae6f
[ Upstream commit 43bb40c5b92659966bdf4bfe584fde0a3575a049 ] When a virtio pci device undergo surprise removal (aka async removal in PCIe spec), mark the device as broken so that any upper layer drivers can abort any outstanding operation. When a virtio net pci device undergo surprise removal which is used by a NetworkManager, a below call trace was observed. kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:1:27059] watchdog: BUG: soft lockup - CPU#1 stuck for 52s! [kworker/1:1:27059] CPU: 1 PID: 27059 Comm: kworker/1:1 Tainted: G S W I L 5.13.0-hotplug+ #8 Hardware name: Dell Inc. PowerEdge R640/0H28RR, BIOS 2.9.4 11/06/2020 Workqueue: events linkwatch_event RIP: 0010:virtnet_send_command+0xfc/0x150 [virtio_net] Call Trace: virtnet_set_rx_mode+0xcf/0x2a7 [virtio_net] ? __hw_addr_create_ex+0x85/0xc0 __dev_mc_add+0x72/0x80 igmp6_group_added+0xa7/0xd0 ipv6_mc_up+0x3c/0x60 ipv6_find_idev+0x36/0x80 addrconf_add_dev+0x1e/0xa0 addrconf_dev_config+0x71/0x130 addrconf_notify+0x1f5/0xb40 ? rtnl_is_locked+0x11/0x20 ? __switch_to_asm+0x42/0x70 ? finish_task_switch+0xaf/0x2c0 ? raw_notifier_call_chain+0x3e/0x50 raw_notifier_call_chain+0x3e/0x50 netdev_state_change+0x67/0x90 linkwatch_do_dev+0x3c/0x50 __linkwatch_run_queue+0xd2/0x220 linkwatch_event+0x21/0x30 process_one_work+0x1c8/0x370 worker_thread+0x30/0x380 ? process_one_work+0x370/0x370 kthread+0x118/0x140 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 Hence, add the ability to abort the command on surprise removal which prevents infinite loop and system lockup. Signed-off-by: Parav Pandit <parav@nvidia.com> Link: https://lore.kernel.org/r/20210721142648.1525924-5-parav@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.