md: get sysfs entry after redundancy attr group create

"sync_completed" and "degraded" belongs to redundancy attr group,
it was not exist yet when md device was created.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: e1a86dbbbd6a ("md: fix deadlock causing by sysfs_notify")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9c69084cae7388172930bb61cc3ce23be1c04bf7..6b511c9007d38cc802d988b49214ccaaba963a7d 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -876,7 +876,13 @@ void mddev_unlock(struct mddev *mddev)
                                sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
                                if (mddev->sysfs_action)
                                        sysfs_put(mddev->sysfs_action);
+                               if (mddev->sysfs_completed)
+                                       sysfs_put(mddev->sysfs_completed);
+                               if (mddev->sysfs_degraded)
+                                       sysfs_put(mddev->sysfs_degraded);
                                mddev->sysfs_action = NULL;
+                               mddev->sysfs_completed = NULL;
+                               mddev->sysfs_degraded = NULL;
                        }
                }
                mddev->sysfs_active = 0;
@@ -4094,6 +4100,8 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
                        pr_warn("md: cannot register extra attributes for %s\n",
                                mdname(mddev));
                mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
+               mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
+               mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
        }
        if (oldpers->sync_request != NULL &&
            pers->sync_request == NULL) {
@@ -5609,14 +5617,9 @@ static void md_free(struct kobject *ko)
 
        if (mddev->sysfs_state)
                sysfs_put(mddev->sysfs_state);
-       if (mddev->sysfs_completed)
-               sysfs_put(mddev->sysfs_completed);
-       if (mddev->sysfs_degraded)
-               sysfs_put(mddev->sysfs_degraded);
        if (mddev->sysfs_level)
                sysfs_put(mddev->sysfs_level);
 
-
        if (mddev->gendisk)
                del_gendisk(mddev->gendisk);
        if (mddev->queue)
@@ -5783,8 +5786,6 @@ static int md_alloc(dev_t dev, char *name)
        if (!error && mddev->kobj.sd) {
                kobject_uevent(&mddev->kobj, KOBJ_ADD);
                mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
-               mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
-               mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
                mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
        }
        mddev_put(mddev);
@@ -6064,6 +6065,8 @@ int md_run(struct mddev *mddev)
                        pr_warn("md: cannot register extra attributes for %s\n",
                                mdname(mddev));
                mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
+               mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
+               mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
        } else if (mddev->ro == 2) /* auto-readonly not meaningful */
                mddev->ro = 0;