Commit 5ecbebc9 authored by Qingfang Deng's avatar Qingfang Deng Committed by Jakub Kicinski
Browse files

ppp: consolidate refcount decrements 



ppp_destroy_{channel,interface} are always called after
refcount_dec_and_test().

To reduce boilerplate code, consolidate the decrements by moving them
into the two functions. To reflect this change in semantics, rename the
functions to ppp_release_*.

Signed-off-by: default avatarQingfang Deng <qingfang.deng@linux.dev>
Link: https://patch.msgid.link/20260407094058.257246-1-qingfang.deng@linux.dev


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 84c5a3f0

drivers/net/ppp/ppp_generic.c

+28 −33
Original line number Diff line number Diff line
@@ -286,12 +286,12 @@ static struct compressor *find_compressor(int type); 
static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);

static int ppp_create_interface(struct net *net, struct file *file, int *unit);

static void init_ppp_file(struct ppp_file *pf, int kind);

static void ppp_destroy_interface(struct ppp *ppp);

static void ppp_release_interface(struct ppp *ppp);

static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);

static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);

static int ppp_connect_channel(struct channel *pch, int unit);

static int ppp_disconnect_channel(struct channel *pch);

static void ppp_destroy_channel(struct channel *pch);

static void ppp_release_channel(struct channel *pch);

static int unit_get(struct idr *p, void *ptr, int min);

static int unit_set(struct idr *p, void *ptr, int n);

static void unit_put(struct idr *p, int n);
@@ -407,24 +407,20 @@ static int ppp_release(struct inode *unused, struct file *file) 


	if (pf) {

		file->private_data = NULL;

		if (pf->kind == INTERFACE) {

		switch (pf->kind) {

		case INTERFACE:

			ppp = PF_TO_PPP(pf);

			rtnl_lock();

			if (file == ppp->owner)

				unregister_netdevice(ppp->dev);

			rtnl_unlock();

		}

		if (refcount_dec_and_test(&pf->refcnt)) {

			switch (pf->kind) {

			case INTERFACE:

				ppp_destroy_interface(PF_TO_PPP(pf));

			ppp_release_interface(ppp);

			break;

		case CHANNEL:

				ppp_destroy_channel(PF_TO_CHANNEL(pf));

			ppp_release_channel(PF_TO_CHANNEL(pf));

			break;

		}

	}

	}

	return 0;

}
@@ -675,8 +671,7 @@ static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 
	synchronize_rcu();



	if (pchb)

		if (refcount_dec_and_test(&pchb->file.refcnt))

			ppp_destroy_channel(pchb);

		ppp_release_channel(pchb);



	return -EALREADY;

}
@@ -708,11 +703,9 @@ static int ppp_unbridge_channels(struct channel *pch) 
	synchronize_rcu();



	if (pchbb == pch)

		if (refcount_dec_and_test(&pch->file.refcnt))

			ppp_destroy_channel(pch);

		ppp_release_channel(pch);



	if (refcount_dec_and_test(&pchb->file.refcnt))

		ppp_destroy_channel(pchb);

	ppp_release_channel(pchb);



	return 0;

}
@@ -786,8 +779,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
				break;

			err = ppp_bridge_channels(pch, pchb);

			/* Drop earlier refcount now bridge establishment is complete */

			if (refcount_dec_and_test(&pchb->file.refcnt))

				ppp_destroy_channel(pchb);

			ppp_release_channel(pchb);

			break;



		case PPPIOCUNBRIDGECHAN:
@@ -1584,8 +1576,7 @@ static void ppp_dev_priv_destructor(struct net_device *dev) 
	struct ppp *ppp;



	ppp = netdev_priv(dev);

	if (refcount_dec_and_test(&ppp->file.refcnt))

		ppp_destroy_interface(ppp);

	ppp_release_interface(ppp);

}



static int ppp_fill_forward_path(struct net_device_path_ctx *ctx,
@@ -3022,8 +3013,7 @@ ppp_unregister_channel(struct ppp_channel *chan) 
	pch->file.dead = 1;

	wake_up_interruptible(&pch->file.rwait);



	if (refcount_dec_and_test(&pch->file.refcnt))

		ppp_destroy_channel(pch);

	ppp_release_channel(pch);

}



/*
@@ -3404,12 +3394,14 @@ init_ppp_file(struct ppp_file *pf, int kind) 
}



/*

 * Free the memory used by a ppp unit.  This is only called once

 * there are no channels connected to the unit and no file structs

 * that reference the unit.

 * Drop a reference to a ppp unit and free its memory if the refcount reaches

 * zero.

 */

static void ppp_destroy_interface(struct ppp *ppp)

static void ppp_release_interface(struct ppp *ppp)

{

	if (!refcount_dec_and_test(&ppp->file.refcnt))

		return;



	atomic_dec(&ppp_unit_count);



	if (!ppp->file.dead || ppp->n_channels) {
@@ -3561,18 +3553,21 @@ ppp_disconnect_channel(struct channel *pch) 
			wake_up_interruptible(&ppp->file.rwait);

		ppp_unlock(ppp);

		synchronize_net();

		if (refcount_dec_and_test(&ppp->file.refcnt))

			ppp_destroy_interface(ppp);

		ppp_release_interface(ppp);

		err = 0;

	}

	return err;

}



/*

 * Free up the resources used by a ppp channel.

 * Drop a reference to a ppp channel and free its memory if the refcount reaches

 * zero.

 */

static void ppp_destroy_channel(struct channel *pch)

static void ppp_release_channel(struct channel *pch)

{

	if (!refcount_dec_and_test(&pch->file.refcnt))

		return;



	put_net_track(pch->chan_net, &pch->ns_tracker);

	pch->chan_net = NULL;