[RFC PATCH 15/27] mm/damon/sysfs: add filter_report_type file under probe filter directory

[SJ Park <sj@kernel.org>]

Add a sysfs file, filter_report_type, under probe filter directory.  It
receives damon_report_type from the user.  Reuse
damon_sysfs_report_type_name struct for user keyword matching.  Move the
definition instead of forward declaration, as the code change is small
enough at this stage.

Signed-off-by: SJ Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 61 +++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 9 deletions(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 7cdbe2fedf7d8..ca971cf1dcf6d 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -977,6 +977,7 @@ struct damon_sysfs_filter {
 	char *path;
 	unsigned long range_min;
 	unsigned long range_max;
+	enum damon_report_type report_type;
 };
 
 static struct damon_sysfs_filter *damon_sysfs_filter_alloc(void)
@@ -1175,6 +1176,53 @@ static ssize_t max_store(struct kobject *kobj,
 	return err ? err : count;
 }
 
+struct damon_sysfs_report_type_name {
+	enum damon_report_type type;
+	char *name;
+};
+
+static const struct damon_sysfs_report_type_name
+damon_sysfs_report_type_names[] = {
+};
+
+static ssize_t filter_report_type_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct damon_sysfs_filter *filter = container_of(kobj,
+			struct damon_sysfs_filter, kobj);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(damon_sysfs_report_type_names); i++) {
+		const struct damon_sysfs_report_type_name *type_name;
+
+		type_name = &damon_sysfs_report_type_names[i];
+		if (type_name->type == filter->report_type)
+			return sysfs_emit(buf, "%s\n", type_name->name);
+	}
+	return -EINVAL;
+}
+
+static ssize_t filter_report_type_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct damon_sysfs_filter *filter = container_of(kobj,
+			struct damon_sysfs_filter, kobj);
+	ssize_t ret = -EINVAL;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(damon_sysfs_report_type_names); i++) {
+		const struct damon_sysfs_report_type_name *type_name;
+
+		type_name = &damon_sysfs_report_type_names[i];
+		if (sysfs_streq(buf, type_name->name)) {
+			filter->report_type = type_name->type;
+			ret = count;
+			break;
+		}
+	}
+	return ret;
+}
+
 static void damon_sysfs_filter_release(struct kobject *kobj)
 {
 	struct damon_sysfs_filter *filter = container_of(kobj,
@@ -1202,6 +1250,9 @@ static struct kobj_attribute damon_sysfs_filter_min_attr =
 static struct kobj_attribute damon_sysfs_filter_max_attr =
 		__ATTR_RW_MODE(max, 0600);
 
+static struct kobj_attribute damon_sysfs_filter_filter_report_type_attr =
+		__ATTR_RW_MODE(filter_report_type, 0600);
+
 static struct attribute *damon_sysfs_filter_attrs[] = {
 	&damon_sysfs_filter_type_attr.attr,
 	&damon_sysfs_filter_matching_attr.attr,
@@ -1209,6 +1260,7 @@ static struct attribute *damon_sysfs_filter_attrs[] = {
 	&damon_sysfs_filter_path_attr.attr,
 	&damon_sysfs_filter_min_attr.attr,
 	&damon_sysfs_filter_max_attr.attr,
+	&damon_sysfs_filter_filter_report_type_attr.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(damon_sysfs_filter);
@@ -2992,15 +3044,6 @@ static struct damon_sysfs_producer *damon_sysfs_producer_alloc(void)
 	return kzalloc_obj(struct damon_sysfs_producer);
 }
 
-struct damon_sysfs_report_type_name {
-	enum damon_report_type type;
-	char *name;
-};
-
-static const struct damon_sysfs_report_type_name
-damon_sysfs_report_type_names[] = {
-};
-
 static ssize_t report_type_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
-- 
2.47.3