Commit 0bc77381 authored by Jeff Layton's avatar Jeff Layton Committed by Al Viro
Browse files

seq_file: add seq_list_*_percpu helpers 



When we convert the file_lock_list to a set of percpu lists, we'll need
a way to iterate over them in order to output /proc/locks info. Add
some seq_list_*_percpu helpers to handle that.

Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Acked-by: default avatarJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 99b072bb

fs/seq_file.c

+54 −0
Original line number Diff line number Diff line
@@ -921,3 +921,57 @@ struct hlist_node *seq_hlist_next_rcu(void *v, 
		return rcu_dereference(node->next);

}

EXPORT_SYMBOL(seq_hlist_next_rcu);



/**

 * seq_hlist_start_precpu - start an iteration of a percpu hlist array

 * @head: pointer to percpu array of struct hlist_heads

 * @cpu:  pointer to cpu "cursor"

 * @pos:  start position of sequence

 *

 * Called at seq_file->op->start().

 */

struct hlist_node *

seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos)

{

	struct hlist_node *node;



	for_each_possible_cpu(*cpu) {

		hlist_for_each(node, per_cpu_ptr(head, *cpu)) {

			if (pos-- == 0)

				return node;

		}

	}

	return NULL;

}

EXPORT_SYMBOL(seq_hlist_start_percpu);



/**

 * seq_hlist_next_percpu - move to the next position of the percpu hlist array

 * @v:    pointer to current hlist_node

 * @head: pointer to percpu array of struct hlist_heads

 * @cpu:  pointer to cpu "cursor"

 * @pos:  start position of sequence

 *

 * Called at seq_file->op->next().

 */

struct hlist_node *

seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head,

			int *cpu, loff_t *pos)

{

	struct hlist_node *node = v;



	++*pos;



	if (node->next)

		return node->next;



	for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids;

	     *cpu = cpumask_next(*cpu, cpu_possible_mask)) {

		struct hlist_head *bucket = per_cpu_ptr(head, *cpu);



		if (!hlist_empty(bucket))

			return bucket->first;

	}

	return NULL;

}

EXPORT_SYMBOL(seq_hlist_next_percpu);

include/linux/seq_file.h

+6 −0
Original line number Diff line number Diff line
@@ -173,4 +173,10 @@ extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, 
extern struct hlist_node *seq_hlist_next_rcu(void *v,

						   struct hlist_head *head,

						   loff_t *ppos);



/* Helpers for iterating over per-cpu hlist_head-s in seq_files */

extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);



extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);



#endif

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