netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: netdev@vger.kernel.org
Cc: devel@linuxdriverproject.org,
	Haiyang Zhang <haiyangz@microsoft.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 5/6] hv_netvsc: synchronize netvsc_change_mtu()/netvsc_set_channels() with netvsc_remove()
Date: Thu, 12 May 2016 14:49:37 +0200	[thread overview]
Message-ID: <1463057378-21118-6-git-send-email-vkuznets@redhat.com> (raw)
In-Reply-To: <1463057378-21118-1-git-send-email-vkuznets@redhat.com>

When netvsc device is removed during mtu change or channels setup we get
into troubles as both paths are trying to remove the device. Synchronize
them with start_remove flag and rtnl lock.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 drivers/net/hyperv/netvsc_drv.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 393403a..71b9125 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -707,7 +707,7 @@ static int netvsc_set_channels(struct net_device *net,
 	int ret = 0;
 	bool recovering = false;
 
-	if (!nvdev || nvdev->destroy)
+	if (net_device_ctx->start_remove || !nvdev || nvdev->destroy)
 		return -ENODEV;
 
 	num_chn = nvdev->num_chn;
@@ -855,7 +855,7 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 	u32 num_chn;
 	int ret = 0;
 
-	if (nvdev == NULL || nvdev->destroy)
+	if (ndevctx->start_remove || !nvdev || nvdev->destroy)
 		return -ENODEV;
 
 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
@@ -1206,7 +1206,12 @@ static int netvsc_remove(struct hv_device *dev)
 	ndev_ctx = netdev_priv(net);
 	net_device = ndev_ctx->nvdev;
 
+	/* Avoid racing with netvsc_change_mtu()/netvsc_set_channels()
+	 * removing the device.
+	 */
+	rtnl_lock();
 	ndev_ctx->start_remove = true;
+	rtnl_unlock();
 
 	cancel_delayed_work_sync(&ndev_ctx->dwork);
 	cancel_work_sync(&ndev_ctx->work);
-- 
2.5.5

  parent reply	other threads:[~2016-05-12 12:49 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-12 12:49 [PATCH 0/6] hv_netvsc: avoid races on mtu change/set channels Vitaly Kuznetsov
2016-05-12 12:49 ` [PATCH 1/6] hv_netvsc: move start_remove flag to net_device_context Vitaly Kuznetsov
2016-05-12 12:49 ` [PATCH 2/6] hv_netvsc: use start_remove flag to protect netvsc_link_change() Vitaly Kuznetsov
2016-05-12 12:49 ` [PATCH 3/6] hv_netvsc: untangle the pointer mess Vitaly Kuznetsov
2016-05-12 12:49 ` [PATCH 4/6] hv_netvsc: get rid of struct net_device pointer in struct netvsc_device Vitaly Kuznetsov
2016-05-12 12:49 ` Vitaly Kuznetsov [this message]
2016-05-12 12:49 ` [PATCH 6/6] hv_netvsc: set nvdev link after populating chn_table Vitaly Kuznetsov
2016-05-12 14:58 ` Aw: [PATCH 0/6] hv_netvsc: avoid races on mtu change/set channels Lino Sanfilippo
2016-05-12 15:09   ` Vitaly Kuznetsov
2016-05-12 16:19     ` Aw: " Lino Sanfilippo

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=1463057378-21118-6-git-send-email-vkuznets@redhat.com \
    --to=vkuznets@redhat.com \
    --cc=devel@linuxdriverproject.org \
    --cc=haiyangz@microsoft.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /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 NNTP newsgroup(s).