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net: fix /proc/net/dev regression

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Commit f04565ddf5 (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 5cac98dd0 (net: Fix corruption
in /proc/*/net/dev_mcast), since its not needed anymore.

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mihai Maruseac <mmaruseac@ixiacom.com>
Tested-by:  Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-04-02 22:33:02 +00:00 committed by David S. Miller
parent 01627d968c
commit 2def16ae6b
3 changed files with 15 additions and 48 deletions
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2
include/linux/netdevice.h
View file

@ -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);

58
net/core/dev.c
View file

@ -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 = {

3
net/core/dev_addr_lists.c
View file

@ -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 = {