From: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, longli@microsoft.com,
yury.norov@gmail.com, leon@kernel.org, cai.huoqing@linux.dev,
ssengar@linux.microsoft.com, vkuznets@redhat.com,
tglx@linutronix.de, linux-hyperv@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rdma@vger.kernel.org
Cc: schakrabarti@microsoft.com,
Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
Subject: [PATCH net] hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove
Date: Tue, 30 Jan 2024 02:16:12 -0800 [thread overview]
Message-ID: <1706609772-5783-1-git-send-email-schakrabarti@linux.microsoft.com> (raw)
In commit ac5047671758 ("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.
Which caused hv_netvsc getting hung at napi_disable, when netvsc_probe()
and netvsc_remove() are happening simultaneously and netvsc_remove()
calls cancel_work_sync(&nvdev->subchan_work) before netvsc_sc_open()
calls napi_enable for the sub channels. Which causes NAPIF_STATE_SCHED
bit not getting cleared for the subchannels.
Now during netvsc_device_remove(), when napi_disable is called for those
subchannels, napi_disable gets stuck on infinite msleep.
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]
Fixes: ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel")
Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
---
drivers/net/hyperv/netvsc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 1dafa44155d0..a6fcbda64ecc 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -708,7 +708,10 @@ void netvsc_device_remove(struct hv_device *device)
/* Disable NAPI and disassociate its context from the device. */
for (i = 0; i < net_device->num_chn; i++) {
/* See also vmbus_reset_channel_cb(). */
- napi_disable(&net_device->chan_table[i].napi);
+ /* only disable enabled NAPI channel */
+ if (i < ndev->real_num_rx_queues)
+ napi_disable(&net_device->chan_table[i].napi);
+
netif_napi_del(&net_device->chan_table[i].napi);
}
--
2.34.1
next reply other threads:[~2024-01-30 10:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-30 10:16 Souradeep Chakrabarti [this message]
2024-01-30 13:19 ` [PATCH net] hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove Haiyang Zhang
2024-01-30 17:32 ` Dexuan Cui
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1706609772-5783-1-git-send-email-schakrabarti@linux.microsoft.com \
--to=schakrabarti@linux.microsoft.com \
--cc=cai.huoqing@linux.dev \
--cc=davem@davemloft.net \
--cc=decui@microsoft.com \
--cc=edumazet@google.com \
--cc=haiyangz@microsoft.com \
--cc=kuba@kernel.org \
--cc=kys@microsoft.com \
--cc=leon@kernel.org \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=longli@microsoft.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=schakrabarti@microsoft.com \
--cc=ssengar@linux.microsoft.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=wei.liu@kernel.org \
--cc=yury.norov@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).