seq_file: Add helpers for iteration over a hlist

Some places in kernel need to iterate over a hlist in seq_file,
so provide some common helpers.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Li Zefan 2010-02-08 23:18:22 +00:00 committed by David S. Miller
parent b1109bf085
commit 66655de6d1
2 changed files with 67 additions and 3 deletions

View file

@ -674,7 +674,6 @@ struct list_head *seq_list_start(struct list_head *head, loff_t pos)
return NULL;
}
EXPORT_SYMBOL(seq_list_start);
struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
@ -684,7 +683,6 @@ struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
return seq_list_start(head, pos - 1);
}
EXPORT_SYMBOL(seq_list_start_head);
struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
@ -695,5 +693,60 @@ struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
++*ppos;
return lh == head ? NULL : lh;
}
EXPORT_SYMBOL(seq_list_next);
/**
* seq_hlist_start - start an iteration of a hlist
* @head: the head of the hlist
* @pos: the start position of the sequence
*
* Called at seq_file->op->start().
*/
struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
{
struct hlist_node *node;
hlist_for_each(node, head)
if (pos-- == 0)
return node;
return NULL;
}
EXPORT_SYMBOL(seq_hlist_start);
/**
* seq_hlist_start_head - start an iteration of a hlist
* @head: the head of the hlist
* @pos: the start position of the sequence
*
* Called at seq_file->op->start(). Call this function if you want to
* print a header at the top of the output.
*/
struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
{
if (!pos)
return SEQ_START_TOKEN;
return seq_hlist_start(head, pos - 1);
}
EXPORT_SYMBOL(seq_hlist_start_head);
/**
* seq_hlist_next - move to the next position of the hlist
* @v: the current iterator
* @head: the head of the hlist
* @pos: the current posision
*
* Called at seq_file->op->next().
*/
struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
loff_t *ppos)
{
struct hlist_node *node = v;
++*ppos;
if (v == SEQ_START_TOKEN)
return head->first;
else
return node->next;
}
EXPORT_SYMBOL(seq_hlist_next);

View file

@ -135,4 +135,15 @@ extern struct list_head *seq_list_start_head(struct list_head *head,
extern struct list_head *seq_list_next(void *v, struct list_head *head,
loff_t *ppos);
/*
* Helpers for iteration over hlist_head-s in seq_files
*/
extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
loff_t *ppos);
#endif