From: Eric Dumazet Date: Mon, 2 Apr 2012 22:33:02 +0000 Subject: [PATCH] net: fix /proc/net/dev regression commit 2def16ae6b0c77571200f18ba4be049b03d75579 upstream. Commit f04565ddf52 (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 Signed-off-by: Eric Dumazet Cc: Mihai Maruseac Tested-by: Ben Greear Signed-off-by: David S. Miller --- include/linux/netdevice.h | 2 -- net/core/dev.c | 58 ++++++++++----------------------------------- net/core/dev_addr_lists.c | 3 ++- 3 files changed, 15 insertions(+), 48 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 1f77540..5cbaa20 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -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); diff --git a/net/core/dev.c b/net/core/dev.c index 6c7dc9d..c25d453 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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 = { diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c index 29c07fe..626698f 100644 --- a/net/core/dev_addr_lists.c +++ b/net/core/dev_addr_lists.c @@ -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 = { -- 1.7.9.5