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Commit 2def16ae authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: fix /proc/net/dev regression 



Commit f04565dd (dev: use name hash for dev_seq_ops) added a second
regression, as some devices are missing from /proc/net/dev if many
devices are defined.

When seq_file buffer is filled, the last ->next/show() method is
canceled (pos value is reverted to value prior ->next() call)

Problem is after above commit, we dont restart the lookup at right
position in ->start() method.

Fix this by removing the internal 'pos' pointer added in commit, since
we need to use the 'loff_t *pos' provided by seq_file layer.

This also reverts commit 5cac98dd (net: Fix corruption
in /proc/*/net/dev_mcast), since its not needed anymore.

Reported-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Cc: Mihai Maruseac <mmaruseac@ixiacom.com>
Tested-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 01627d96

include/linux/netdevice.h

+0 −2
Original line number Diff line number Diff line
@@ -2604,8 +2604,6 @@ extern void net_disable_timestamp(void); 
extern void *dev_seq_start(struct seq_file *seq, loff_t *pos);

extern void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos);

extern void dev_seq_stop(struct seq_file *seq, void *v);

extern int dev_seq_open_ops(struct inode *inode, struct file *file,

			    const struct seq_operations *ops);

#endif



extern int netdev_class_create_file(struct class_attribute *class_attr);

net/core/dev.c

+13 −45
Original line number Diff line number Diff line
@@ -4028,54 +4028,41 @@ static int dev_ifconf(struct net *net, char __user *arg) 


#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 BUCKET_SPACE (32 - NETDEV_HASHBITS - 1)



#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)

static inline struct net_device *dev_from_same_bucket(struct seq_file *seq, loff_t *pos)

{

	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;

	unsigned int count = 0, offset = get_offset(*pos);



	bucket = get_bucket(state->pos);

	offset = get_offset(state->pos);

	h = &net->dev_name_head[bucket];

	count = 0;

	h = &net->dev_name_head[get_bucket(*pos)];

	hlist_for_each_entry_rcu(dev, p, h, name_hlist) {

		if (count++ == offset) {

			state->pos = set_bucket_offset(bucket, count);

		if (++count == offset)

			return dev;

	}

	}



	return NULL;

}



static inline struct net_device *dev_from_new_bucket(struct seq_file *seq)

static inline struct net_device *dev_from_bucket(struct seq_file *seq, loff_t *pos)

{

	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);

		dev = dev_from_same_bucket(seq, pos);

		if (dev)

			return dev;



		bucket++;

		state->pos = set_bucket_offset(bucket, 0);

		bucket = get_bucket(*pos) + 1;

		*pos = set_bucket_offset(bucket, 1);

	} while (bucket < NETDEV_HASHENTRIES);



	return NULL;
@@ -4088,33 +4075,20 @@ static inline struct net_device *dev_from_new_bucket(struct seq_file *seq) 
void *dev_seq_start(struct seq_file *seq, loff_t *pos)

	__acquires(RCU)

{

	struct dev_iter_state *state = seq->private;



	rcu_read_lock();

	if (!*pos)

		return SEQ_START_TOKEN;



	/* check for end of the hash */

	if (state->pos == 0 && *pos > 1)

	if (get_bucket(*pos) >= NETDEV_HASHENTRIES)

		return NULL;



	return dev_from_new_bucket(seq);

	return dev_from_bucket(seq, pos);

}



void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)

{

	struct net_device *dev;



	++*pos;



	if (v == SEQ_START_TOKEN)

		return dev_from_new_bucket(seq);



	dev = dev_from_same_bucket(seq);

	if (dev)

		return dev;



	return dev_from_new_bucket(seq);

	return dev_from_bucket(seq, pos);

}



void dev_seq_stop(struct seq_file *seq, void *v)
@@ -4213,13 +4187,7 @@ static const struct seq_operations dev_seq_ops = { 
static int dev_seq_open(struct inode *inode, struct file *file)

{

	return seq_open_net(inode, file, &dev_seq_ops,

			    sizeof(struct dev_iter_state));

}



int dev_seq_open_ops(struct inode *inode, struct file *file,

		     const struct seq_operations *ops)

{

	return seq_open_net(inode, file, ops, sizeof(struct dev_iter_state));

			    sizeof(struct seq_net_private));

}



static const struct file_operations dev_seq_fops = {

net/core/dev_addr_lists.c

+2 −1
Original line number Diff line number Diff line
@@ -696,7 +696,8 @@ static const struct seq_operations dev_mc_seq_ops = { 


static int dev_mc_seq_open(struct inode *inode, struct file *file)

{

	return dev_seq_open_ops(inode, file, &dev_mc_seq_ops);

	return seq_open_net(inode, file, &dev_mc_seq_ops,

			    sizeof(struct seq_net_private));

}



static const struct file_operations dev_mc_seq_fops = {