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: Jeff Layton <jlayton@xxxxxxxxxx>
Acked-by: J. Bruce Fields <bfields@xxxxxxxxxxxx>
---
fs/seq_file.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/seq_file.h | 6 +++++
2 files changed, 60 insertions(+), 0 deletions(-)
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 774c1eb..3135c25 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -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);
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 2da29ac..4e32edc 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -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
--
1.7.1
--
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