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| author | Li Zefan <lizf@cn.fujitsu.com> | 2010-02-08 23:18:22 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-02-10 11:12:06 -0800 |
| commit | 66655de6d132b726be64c324bc3f9ea366d20697 (patch) | |
| tree | d88c42a19de245e4a81337eef6bf06555586005d | |
| parent | b1109bf085c8dd69537b7876ea83f914dd1fe46a (diff) | |
| download | lwn-66655de6d132b726be64c324bc3f9ea366d20697.tar.gz lwn-66655de6d132b726be64c324bc3f9ea366d20697.zip | |
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>
| -rw-r--r-- | fs/seq_file.c | 59 | ||||
| -rw-r--r-- | include/linux/seq_file.h | 11 |
2 files changed, 67 insertions, 3 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c index eae7d9dbf3ff..f65b16f02da3 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -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); diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 8366d8f12e53..c95bcdc18f4c 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -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 |