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

When a DAMOS-scheme DAMON sysfs directory setup fails after setup of
access_pattern/ directory, subdirectories of access_pattern/ 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/20251225023043.18579-5-sj@kernel.org
Fixes: 9bbb820a5bd5 ("mm/damon/sysfs: support DAMOS quotas")
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>

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 2c7a2b54be5765bc5ff49df4c52a241bd4662ea2..3a699dcd5a7fe1529279e42eee874086f2fe9c2a 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -2152,7 +2152,7 @@ static int damon_sysfs_scheme_add_dirs(struct damon_sysfs_scheme *scheme)
                return err;
        err = damos_sysfs_set_dests(scheme);
        if (err)
-               goto put_access_pattern_out;
+               goto rmdir_put_access_pattern_out;
        err = damon_sysfs_scheme_set_quotas(scheme);
        if (err)
                goto put_dests_out;
@@ -2190,7 +2190,8 @@ rmdir_put_quotas_access_pattern_out:
 put_dests_out:
        kobject_put(&scheme->dests->kobj);
        scheme->dests = NULL;
-put_access_pattern_out:
+rmdir_put_access_pattern_out:
+       damon_sysfs_access_pattern_rm_dirs(scheme->access_pattern);
        kobject_put(&scheme->access_pattern->kobj);
        scheme->access_pattern = NULL;
        return err;