[RFC net-next 1/3] ppp: use file.dead to check channel unregistration
From: Qingfang Deng <hidden>
Date: 2026-04-16 08:27:12
Also in:
lkml
Subsystem:
networking drivers, ppp protocol drivers and compressors, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Currently, ppp_generic checks if pch->chan is NULL to determine if a channel is being unregistered. However, struct ppp_file already has a 'dead' flag for this purpose, which is used by ppp units and other parts of the driver. Switch all pch->chan NULL checks to pch->file.dead checks. In ppp_unregister_channel, move the setting of pch->file.dead inside the locked section to ensure atomicity and remove the now redundant pch->chan = NULL assignment. This is a preparation to eventually unify 'struct ppp_channel' and 'struct channel' into a single struct. Signed-off-by: Qingfang Deng <redacted> --- drivers/net/ppp/ppp_generic.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index b0d3bc49c685..fd2889e374c9 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c@@ -790,7 +790,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) down_read(&pch->chan_sem); chan = pch->chan; err = -ENOTTY; - if (chan && chan->ops->ioctl) + if (!pch->file.dead && chan->ops->ioctl) err = chan->ops->ioctl(chan, cmd, arg); up_read(&pch->chan_sem); }
@@ -2167,7 +2167,7 @@ static void __ppp_channel_push(struct channel *pch, struct ppp *ppp) struct sk_buff *skb; spin_lock(&pch->downl); - if (pch->chan) { + if (!pch->file.dead) { while (!skb_queue_empty(&pch->file.xq)) { skb = skb_dequeue(&pch->file.xq); if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
@@ -2288,7 +2288,7 @@ static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) goto out_rcu; spin_lock_bh(&pchb->downl); - if (!pchb->chan) { + if (pchb->file.dead) { /* channel got unregistered */ kfree_skb(skb); goto outl;
@@ -3002,7 +3002,7 @@ ppp_unregister_channel(struct ppp_channel *chan) ppp_disconnect_channel(pch); down_write(&pch->chan_sem); spin_lock_bh(&pch->downl); - pch->chan = NULL; + pch->file.dead = 1; spin_unlock_bh(&pch->downl); up_write(&pch->chan_sem);
@@ -3013,7 +3013,6 @@ ppp_unregister_channel(struct ppp_channel *chan) ppp_unbridge_channels(pch); - pch->file.dead = 1; wake_up_interruptible(&pch->file.rwait); ppp_release_channel(pch);
@@ -3505,7 +3504,7 @@ ppp_connect_channel(struct channel *pch, int unit) ppp_lock(ppp); spin_lock_bh(&pch->downl); - if (!pch->chan) { + if (pch->file.dead) { /* Don't connect unregistered channels */ spin_unlock_bh(&pch->downl); ppp_unlock(ppp);
--
2.43.0