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| author | Qingfang Deng <qingfang.deng@linux.dev> | 2026-07-27 11:28:00 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-07-28 19:13:51 -0700 |
| commit | 2bb54b49e9d522f54dc9c0fe10ba40fbc56041c8 (patch) | |
| tree | 87570d330b621bd9620829faf42352304c1193ae | |
| parent | 11291f123073aa143709770ba988cba41bfc4057 (diff) | |
| download | linux-next-2bb54b49e9d522f54dc9c0fe10ba40fbc56041c8.tar.gz linux-next-2bb54b49e9d522f54dc9c0fe10ba40fbc56041c8.zip | |
ppp: convert chan_sem to a mutex
chan_sem's read-side lock is taken under another mutex, so there is no
benefit in keeping it as an rwsem. Replace the rwsem with a mutex.
Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Link: https://patch.msgid.link/20260727032802.4090-1-qingfang.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index cacc4c3a37d2..08bb89765487 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -39,7 +39,6 @@ #include <linux/ip.h> #include <linux/tcp.h> #include <linux/spinlock.h> -#include <linux/rwsem.h> #include <linux/stddef.h> #include <linux/device.h> #include <linux/mutex.h> @@ -176,7 +175,7 @@ struct channel { struct ppp_file file; /* stuff for read/write/poll */ struct list_head list; /* link in all/new_channels list */ struct ppp_channel *chan; /* public channel data structure */ - struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ + struct mutex chan_sem; /* protects `chan' during chan ioctl */ spinlock_t downl; /* protects `chan', file.xq dequeue */ struct ppp __rcu *ppp; /* ppp unit we're connected to */ struct net *chan_net; /* the net channel belongs to */ @@ -788,12 +787,12 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; default: - down_read(&pch->chan_sem); + mutex_lock(&pch->chan_sem); chan = pch->chan; err = -ENOTTY; if (chan && chan->ops->ioctl) err = chan->ops->ioctl(chan, cmd, arg); - up_read(&pch->chan_sem); + mutex_unlock(&pch->chan_sem); } goto out; } @@ -2922,7 +2921,7 @@ int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) #ifdef CONFIG_PPP_MULTILINK pch->lastseq = -1; #endif /* CONFIG_PPP_MULTILINK */ - init_rwsem(&pch->chan_sem); + mutex_init(&pch->chan_sem); spin_lock_init(&pch->downl); spin_lock_init(&pch->upl); @@ -3005,11 +3004,11 @@ ppp_unregister_channel(struct ppp_channel *chan) * the channel's start_xmit or ioctl routine before we proceed. */ ppp_disconnect_channel(pch); - down_write(&pch->chan_sem); + mutex_lock(&pch->chan_sem); spin_lock_bh(&pch->downl); pch->chan = NULL; spin_unlock_bh(&pch->downl); - up_write(&pch->chan_sem); + mutex_unlock(&pch->chan_sem); pn = ppp_pernet(pch->chan_net); spin_lock_bh(&pn->all_channels_lock); @@ -3600,6 +3599,7 @@ static void ppp_release_channel(struct channel *pch) pr_err("ppp: destroying undead channel %p !\n", pch); return; } + mutex_destroy(&pch->chan_sem); call_rcu(&pch->rcu, ppp_release_channel_free); } |