Messages in this thread Patch in this message | | | Date | Mon, 21 Apr 2014 15:54:42 +0400 | From | Sergei Shtylyov <> | Subject | Re: [PATCH 1/1] net: Add rtnl_lock for netif_device_attach/detach |
| |
Hello.
On 21-04-2014 10:30, Li, ZhenHua wrote:
> The comment is trying to explain why add a lock here.
I can read, thanks. :-) I was wondering about the kernel-doc comment style you've used; AFAIK, it's only good for documenting functions and data structures. The normal multi-line comment style in the networking code is this:
/* bla * bla */
>>> From: "Li, Zhen-Hua" <zhen-hual@hp.com>
>>> As netif_running is called in netif_device_attach/detach. There should be >>> rtnl_lock/unlock called, to avoid dev stat change during netif_device_attach >>> and detach being called. >>> I checked NIC some drivers, some of them have netif_device_attach/detach >>> called between rtnl_lock/unlock, while some drivers do not.
>>> This patch is tring to find a generic way to fix this for all NIC drivers.
>>> Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com> >>> --- >>> net/core/dev.c | 18 ++++++++++++++++++ >>> 1 file changed, 18 insertions(+)
>>> diff --git a/net/core/dev.c b/net/core/dev.c >>> index 5b3042e..795bbc5 100644 >>> --- a/net/core/dev.c >>> +++ b/net/core/dev.c >>> @@ -2190,10 +2190,19 @@ EXPORT_SYMBOL(__dev_kfree_skb_any); >>> */ >>> void netif_device_detach(struct net_device *dev) >>> { >>> + /**
>> Hm, why kernel-doc style comment here?
>>> + * As netif_running is called , rtnl_lock and unlock are needed to
Space before comma not needed.
>>> + * avoid __LINK_STATE_START bit changes during this function call. >>> + */ >>> + int need_unlock; >>> + >>> + need_unlock = rtnl_trylock(); >>> if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) && >>> netif_running(dev)) { >>> netif_tx_stop_all_queues(dev); >>> } >>> + if (need_unlock) >>> + rtnl_unlock(); >>> } >>> EXPORT_SYMBOL(netif_device_detach); >>> >>> @@ -2205,11 +2214,20 @@ EXPORT_SYMBOL(netif_device_detach); >>> */ >>> void netif_device_attach(struct net_device *dev) >>> { >>> + /**
>> ... and here?
>>> + * As netif_running is called , rtnl_lock and unlock are needed to
Space before comma not needed.
>>> + * avoid __LINK_STATE_START bit changes during this function call. >>> + */
WBR, Sergei
| |