dev: use name hash for dev_seq_ops (f04565dd) · Commits · 戴 / test

net/core/dev.c

+69 −15

Original line number	Original line	Diff line number	Diff line
	@@ -4093,6 +4093,60 @@ static int dev_ifconf(struct net net, char __user arg)
	}		}

	#ifdef CONFIG_PROC_FS		#ifdef CONFIG_PROC_FS

			#define BUCKET_SPACE (32 - NETDEV_HASHBITS)

			struct dev_iter_state {
			struct seq_net_private p;
			unsigned int pos; /* bucket << BUCKET_SPACE + offset */
			};

			#define get_bucket(x) ((x) >> BUCKET_SPACE)
			#define get_offset(x) ((x) & ((1 << BUCKET_SPACE) - 1))
			#define set_bucket_offset(b, o) ((b) << BUCKET_SPACE \| (o))

			static inline struct net_device dev_from_same_bucket(struct seq_file seq)
			{
			struct dev_iter_state *state = seq->private;
			struct net *net = seq_file_net(seq);
			struct net_device *dev;
			struct hlist_node *p;
			struct hlist_head *h;
			unsigned int count, bucket, offset;

			bucket = get_bucket(state->pos);
			offset = get_offset(state->pos);
			h = &net->dev_name_head[bucket];
			count = 0;
			hlist_for_each_entry_rcu(dev, p, h, name_hlist) {
			if (count++ == offset) {
			state->pos = set_bucket_offset(bucket, count);
			return dev;
			}
			}

			return NULL;
			}

			static inline struct net_device dev_from_new_bucket(struct seq_file seq)
			{
			struct dev_iter_state *state = seq->private;
			struct net_device *dev;
			unsigned int bucket;

			bucket = get_bucket(state->pos);
			do {
			dev = dev_from_same_bucket(seq);
			if (dev)
			return dev;

			bucket++;
			state->pos = set_bucket_offset(bucket, 0);
			} while (bucket < NETDEV_HASHENTRIES);

			return NULL;
			}

	/*		/*
	* This is invoked by the /proc filesystem handler to display a device		* This is invoked by the /proc filesystem handler to display a device
	* in detail.		* in detail.
	@@ -4100,33 +4154,33 @@ static int dev_ifconf(struct net net, char __user arg)
	void dev_seq_start(struct seq_file seq, loff_t *pos)		void dev_seq_start(struct seq_file seq, loff_t *pos)
	__acquires(RCU)		__acquires(RCU)
	{		{
	struct net *net = seq_file_net(seq);		struct dev_iter_state *state = seq->private;
	loff_t off;
	struct net_device *dev;

	rcu_read_lock();		rcu_read_lock();
	if (!*pos)		if (!*pos)
	return SEQ_START_TOKEN;		return SEQ_START_TOKEN;

	off = 1;		/* check for end of the hash */
	for_each_netdev_rcu(net, dev)		if (state->pos == 0 && *pos > 1)
	if (off++ == *pos)
	return dev;

	return NULL;		return NULL;

			return dev_from_new_bucket(seq);
	}		}

	void dev_seq_next(struct seq_file seq, void v, loff_t pos)		void dev_seq_next(struct seq_file seq, void v, loff_t pos)
	{		{
	struct net_device *dev = v;		struct net_device *dev;

			++*pos;

	if (v == SEQ_START_TOKEN)		if (v == SEQ_START_TOKEN)
	dev = first_net_device_rcu(seq_file_net(seq));		return dev_from_new_bucket(seq);
	else
	dev = next_net_device_rcu(dev);

	++*pos;		dev = dev_from_same_bucket(seq);
			if (dev)
	return dev;		return dev;

			return dev_from_new_bucket(seq);
	}		}

	void dev_seq_stop(struct seq_file seq, void v)		void dev_seq_stop(struct seq_file seq, void v)
	@@ -4225,7 +4279,7 @@ static const struct seq_operations dev_seq_ops = {
	static int dev_seq_open(struct inode inode, struct file file)		static int dev_seq_open(struct inode inode, struct file file)
	{		{
	return seq_open_net(inode, file, &dev_seq_ops,		return seq_open_net(inode, file, &dev_seq_ops,
	sizeof(struct seq_net_private));		sizeof(struct dev_iter_state));
	}		}

	static const struct file_operations dev_seq_fops = {		static const struct file_operations dev_seq_fops = {

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