[RFC PATCH v2 07/11] mm/damon/sysfs-schemes: connect filter directory and filters directory

SeongJae Park
2022-11-30T20:10:10Z

Implement 'nr_filters' file under 'filters' directory, which will be
used to populate specific number of 'filter' directory under the
directory, similar to other 'nr_*' files in DAMON sysfs interface.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
mm/damon/sysfs-schemes.c | 68 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index afbfc55a8e84..e79c678a69d5 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -269,6 +269,11 @@ struct damon_sysfs_scheme_filter {
char *memcg_path;
};

+static struct damon_sysfs_scheme_filter *damon_sysfs_scheme_filter_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_scheme_filter), GFP_KERNEL);
+}
+
/* Should match with enum damos_filter_type */
static const char * const damon_sysfs_scheme_filter_type_strs[] = {
"anon",
@@ -392,6 +397,7 @@ static struct kobj_type damon_sysfs_scheme_filter_ktype = {

struct damon_sysfs_scheme_filters {
struct kobject kobj;
+ struct damon_sysfs_scheme_filter **filters_arr;
int nr;
};

@@ -401,6 +407,57 @@ damon_sysfs_scheme_filters_alloc(void)
return kzalloc(sizeof(struct damon_sysfs_scheme_filters), GFP_KERNEL);
}

+static void damon_sysfs_scheme_filters_rm_dirs(
+ struct damon_sysfs_scheme_filters *filters)
+{
+ struct damon_sysfs_scheme_filter **filters_arr = filters->filters_arr;
+ int i;
+
+ for (i = 0; i < filters->nr; i++)
+ kobject_put(&filters_arr[i]->kobj);
+ filters->nr = 0;
+ kfree(filters_arr);
+ filters->filters_arr = NULL;
+}
+
+static int damon_sysfs_scheme_filters_add_dirs(
+ struct damon_sysfs_scheme_filters *filters, int nr_filters)
+{
+ struct damon_sysfs_scheme_filter **filters_arr, *filter;
+ int err, i;
+
+ damon_sysfs_scheme_filters_rm_dirs(filters);
+ if (!nr_filters)
+ return 0;
+
+ filters_arr = kmalloc_array(nr_filters, sizeof(*filters_arr),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!filters_arr)
+ return -ENOMEM;
+ filters->filters_arr = filters_arr;
+
+ for (i = 0; i < nr_filters; i++) {
+ filter = damon_sysfs_scheme_filter_alloc();
+ if (!filter) {
+ damon_sysfs_scheme_filters_rm_dirs(filters);
+ return -ENOMEM;
+ }
+
+ err = kobject_init_and_add(&filter->kobj,
+ &damon_sysfs_scheme_filter_ktype,
+ &filters->kobj, "%d", i);
+ if (err) {
+ kobject_put(&filter->kobj);
+ damon_sysfs_scheme_filters_rm_dirs(filters);
+ return err;
+ }
+
+ filters_arr[i] = filter;
+ filters->nr++;
+ }
+ return 0;
+}
+
static ssize_t nr_filters_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -413,6 +470,7 @@ static ssize_t nr_filters_show(struct kobject *kobj,
static ssize_t nr_filters_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
+ struct damon_sysfs_scheme_filters *filters;
int nr, err = kstrtoint(buf, 0, &nr);

if (err)
@@ -420,6 +478,15 @@ static ssize_t nr_filters_store(struct kobject *kobj,
if (nr < 0)
return -EINVAL;

+ filters = container_of(kobj, struct damon_sysfs_scheme_filters, kobj);
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ err = damon_sysfs_scheme_filters_add_dirs(filters, nr);
+ mutex_unlock(&damon_sysfs_lock);
+ if (err)
+ return err;
+
return count;
}

@@ -1166,6 +1233,7 @@ static void damon_sysfs_scheme_rm_dirs(struct damon_sysfs_scheme *scheme)
damon_sysfs_quotas_rm_dirs(scheme->quotas);
kobject_put(&scheme->quotas->kobj);
kobject_put(&scheme->watermarks->kobj);
+ damon_sysfs_scheme_filters_rm_dirs(scheme->filters);
kobject_put(&scheme->filters->kobj);
kobject_put(&scheme->stats->kobj);
damon_sysfs_scheme_regions_rm_dirs(scheme->tried_regions);
--
2.25.1