[PATCH v5 2/4] mm/damon/sysfs-schemes: add files for setting damos_filter->sz_range

[Usama Arif <usamaarif642@xxxxxxxxx>]

Add min and max files for damon filters to let the userspace decide
the min/max folio size to operate on. This will be needed to decide
what folio sizes to give pa_stat for.

Signed-off-by: Usama Arif <usamaarif642@xxxxxxxxx>
---
 mm/damon/sysfs-schemes.c | 54 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 9020bc9befac..881d00bb3a34 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -316,6 +316,7 @@ struct damon_sysfs_scheme_filter {
 	bool allow;
 	char *memcg_path;
 	struct damon_addr_range addr_range;
+	struct damon_size_range sz_range;
 	int target_idx;
 };
 
@@ -474,6 +475,44 @@ static ssize_t addr_end_store(struct kobject *kobj,
 	return err ? err : count;
 }
 
+static ssize_t min_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
+			struct damon_sysfs_scheme_filter, kobj);
+
+	return sysfs_emit(buf, "%lu\n", filter->sz_range.min);
+}
+
+static ssize_t min_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
+			struct damon_sysfs_scheme_filter, kobj);
+	int err = kstrtoul(buf, 0, &filter->sz_range.min);
+
+	return err ? err : count;
+}
+
+static ssize_t max_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
+			struct damon_sysfs_scheme_filter, kobj);
+
+	return sysfs_emit(buf, "%lu\n", filter->sz_range.max);
+}
+
+static ssize_t max_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct damon_sysfs_scheme_filter *filter = container_of(kobj,
+			struct damon_sysfs_scheme_filter, kobj);
+	int err = kstrtoul(buf, 0, &filter->sz_range.max);
+
+	return err ? err : count;
+}
+
 static ssize_t damon_target_idx_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
@@ -520,6 +559,12 @@ static struct kobj_attribute damon_sysfs_scheme_filter_addr_start_attr =
 static struct kobj_attribute damon_sysfs_scheme_filter_addr_end_attr =
 		__ATTR_RW_MODE(addr_end, 0600);
 
+static struct kobj_attribute damon_sysfs_scheme_filter_min_attr =
+		__ATTR_RW_MODE(min, 0600);
+
+static struct kobj_attribute damon_sysfs_scheme_filter_max_attr =
+		__ATTR_RW_MODE(max, 0600);
+
 static struct kobj_attribute damon_sysfs_scheme_filter_damon_target_idx_attr =
 		__ATTR_RW_MODE(damon_target_idx, 0600);
 
@@ -530,6 +575,8 @@ static struct attribute *damon_sysfs_scheme_filter_attrs[] = {
 	&damon_sysfs_scheme_filter_memcg_path_attr.attr,
 	&damon_sysfs_scheme_filter_addr_start_attr.attr,
 	&damon_sysfs_scheme_filter_addr_end_attr.attr,
+	&damon_sysfs_scheme_filter_min_attr.attr,
+	&damon_sysfs_scheme_filter_max_attr.attr,
 	&damon_sysfs_scheme_filter_damon_target_idx_attr.attr,
 	NULL,
 };
@@ -1954,6 +2001,13 @@ static int damon_sysfs_add_scheme_filters(struct damos *scheme,
 			filter->addr_range = sysfs_filter->addr_range;
 		} else if (filter->type == DAMOS_FILTER_TYPE_TARGET) {
 			filter->target_idx = sysfs_filter->target_idx;
+		} else if (filter->type == DAMOS_FILTER_TYPE_HUGEPAGE_SIZE) {
+			if (sysfs_filter->sz_range.min >
+					sysfs_filter->sz_range.max) {
+				damos_destroy_filter(filter);
+				return -EINVAL;
+			}
+			filter->sz_range = sysfs_filter->sz_range;
 		}
 
 		damos_add_filter(scheme, filter);
-- 
2.43.5