mm/damon/sysfs-scheme: cleanup quotas subdirs on scheme dir setup failure

commit dc7e1d75fd8c505096d0cddeca9e2efb2b55aaf9 upstream.

When a DAMOS-scheme DAMON sysfs directory setup fails after setup of
quotas/ directory, subdirectories of quotas/ directory are not cleaned up.
As a result, DAMON sysfs interface is nearly broken until the system
reboots, and the memory for the unremoved directory is leaked.

Cleanup the directories under such failures.

Link: https://lkml.kernel.org/r/20251225023043.18579-4-sj@kernel.org
Fixes: 1b32234ab087 ("mm/damon/sysfs: support DAMOS watermarks")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: chongjiapeng <jiapeng.chong@linux.alibaba.com>
Cc: <stable@vger.kernel.org> # 5.18.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index d9e01648db70ecef6839404704af91f4ae87c2c1..c7c2972c7c8a944406ae826d0a1ba7b01561ed85 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -1609,7 +1609,7 @@ static int damon_sysfs_scheme_add_dirs(struct damon_sysfs_scheme *scheme)
                goto put_access_pattern_out;
        err = damon_sysfs_scheme_set_watermarks(scheme);
        if (err)
-               goto put_quotas_access_pattern_out;
+               goto rmdir_put_quotas_access_pattern_out;
        err = damon_sysfs_scheme_set_filters(scheme);
        if (err)
                goto put_watermarks_quotas_access_pattern_out;
@@ -1630,7 +1630,8 @@ put_filters_watermarks_quotas_access_pattern_out:
 put_watermarks_quotas_access_pattern_out:
        kobject_put(&scheme->watermarks->kobj);
        scheme->watermarks = NULL;
-put_quotas_access_pattern_out:
+rmdir_put_quotas_access_pattern_out:
+       damon_sysfs_quotas_rm_dirs(scheme->quotas);
        kobject_put(&scheme->quotas->kobj);
        scheme->quotas = NULL;
 put_access_pattern_out: