Souradeep Chakrabarti e0526ec536 hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove ... In commit ac50476717 ("hv_netvsc: Disable NAPI before closing the VMBus channel"), napi_disable was getting called for all channels, including all subchannels without confirming if they are enabled or not. This caused hv_netvsc getting hung at napi_disable, when netvsc_probe() has finished running but nvdev->subchan_work has not started yet. netvsc_subchan_work() -> rndis_set_subchannel() has not created the sub-channels and because of that netvsc_sc_open() is not running. netvsc_remove() calls cancel_work_sync(&nvdev->subchan_work), for which netvsc_subchan_work did not run. netif_napi_add() sets the bit NAPI_STATE_SCHED because it ensures NAPI cannot be scheduled. Then netvsc_sc_open() -> napi_enable will clear the NAPIF_STATE_SCHED bit, so it can be scheduled. napi_disable() does the opposite. Now during netvsc_device_remove(), when napi_disable is called for those subchannels, napi_disable gets stuck on infinite msleep. This fix addresses this problem by ensuring that napi_disable() is not getting called for non-enabled NAPI struct. But netif_napi_del() is still necessary for these non-enabled NAPI struct for cleanup purpose. Call trace: [ 654.559417] task:modprobe state:D stack: 0 pid: 2321 ppid: 1091 flags:0x00004002 [ 654.568030] Call Trace: [ 654.571221] <TASK> [ 654.573790] __schedule+0x2d6/0x960 [ 654.577733] schedule+0x69/0xf0 [ 654.581214] schedule_timeout+0x87/0x140 [ 654.585463] ? __bpf_trace_tick_stop+0x20/0x20 [ 654.590291] msleep+0x2d/0x40 [ 654.593625] napi_disable+0x2b/0x80 [ 654.597437] netvsc_device_remove+0x8a/0x1f0 [hv_netvsc] [ 654.603935] rndis_filter_device_remove+0x194/0x1c0 [hv_netvsc] [ 654.611101] ? do_wait_intr+0xb0/0xb0 [ 654.615753] netvsc_remove+0x7c/0x120 [hv_netvsc] [ 654.621675] vmbus_remove+0x27/0x40 [hv_vmbus] Cc: stable@vger.kernel.org Fixes: ac50476717 ("hv_netvsc: Disable NAPI before closing the VMBus channel") Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/1706686551-28510-1-git-send-email-schakrabarti@linux.microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>		2024-02-01 08:33:43 -08:00
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hyperv_net.h	eth: add missing xdp.h includes in drivers	2023-08-03 08:38:07 -07:00
Kconfig	hv_netvsc: rndis_filter needs to select NLS	2023-12-01 20:12:24 -08:00
Makefile	hv_netvsc: Add XDP support	2020-01-25 10:43:19 +01:00
netvsc_bpf.c	hv_netvsc: Add support for XDP_REDIRECT	2022-04-11 18:25:47 -07:00
netvsc_drv.c	hv_netvsc: Calculate correct ring size when PAGE_SIZE is not 4 Kbytes	2024-01-23 17:19:42 -08:00
netvsc_trace.c
netvsc_trace.h
netvsc.c	hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove	2024-02-01 08:33:43 -08:00
rndis_filter.c	hv_netvsc: remove duplicated including of slab.h	2023-12-15 12:19:00 +00:00