[RFC PATCH v2 26/28] mm/damon/sysfs: setup damon_filter->memcg_id from path

[SeongJae Park <sj@kernel.org>]

Find and set the memcg_id for damon_filter from the user-passed memory
cgroup path when updating the DAMON input parameters.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/damon.h |  1 +
 mm/damon/core.c       |  2 +-
 mm/damon/sysfs.c      | 11 +++++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 3dec0947b93f0..6935cc3ea00ab 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -1004,6 +1004,7 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
 struct damon_filter *damon_new_filter(enum damon_filter_type type,
 		bool matching, bool allow);
 void damon_add_filter(struct damon_probe *probe, struct damon_filter *f);
+void damon_destroy_filter(struct damon_filter *f);
 
 struct damon_probe *damon_new_probe(void);
 void damon_add_probe(struct damon_ctx *ctx, struct damon_probe *probe);
diff --git a/mm/damon/core.c b/mm/damon/core.c
index ef751898a3c06..89568f463e556 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -143,7 +143,7 @@ static void damon_free_filter(struct damon_filter *f)
 	kfree(f);
 }
 
-static void damon_destroy_filter(struct damon_filter *f)
+void damon_destroy_filter(struct damon_filter *f)
 {
 	damon_del_filter(f);
 	damon_free_filter(f);
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 2b68e1a7de451..0b7b0ef345cc8 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1927,6 +1927,17 @@ static int damon_sysfs_set_probes(struct damon_ctx *ctx,
 					sys_filter->allow);
 			if (!filter)
 				return -ENOMEM;
+			if (filter->type == DAMON_FILTER_TYPE_MEMCG) {
+				int err;
+
+				err = damon_sysfs_memcg_path_to_id(
+						sys_filter->path,
+						&filter->memcg_id);
+				if (err) {
+					damon_destroy_filter(filter);
+					return err;
+				}
+			}
 			damon_add_filter(c, filter);
 		}
 	}
-- 
2.47.3