diff --git a/fs/seq_file.c b/fs/seq_file.c index 0ac22af7afe5..49194a4e6b91 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -447,3 +447,37 @@ int seq_puts(struct seq_file *m, const char *s) return -1; } EXPORT_SYMBOL(seq_puts); + +struct list_head *seq_list_start(struct list_head *head, loff_t pos) +{ + struct list_head *lh; + + list_for_each(lh, head) + if (pos-- == 0) + return lh; + + return NULL; +} + +EXPORT_SYMBOL(seq_list_start); + +struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) +{ + if (!pos) + return head; + + 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) +{ + struct list_head *lh; + + lh = ((struct list_head *)v)->next; + ++*ppos; + return lh == head ? NULL : lh; +} + +EXPORT_SYMBOL(seq_list_next); diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 3e3cccbb1cac..83783ab0f552 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -50,5 +50,16 @@ int seq_release_private(struct inode *, struct file *); #define SEQ_START_TOKEN ((void *)1) +/* + * Helpers for iteration over list_head-s in seq_files + */ + +extern struct list_head *seq_list_start(struct list_head *head, + loff_t pos); +extern struct list_head *seq_list_start_head(struct list_head *head, + loff_t pos); +extern struct list_head *seq_list_next(void *v, struct list_head *head, + loff_t *ppos); + #endif #endif