函数源码

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source File:fs\notify\mark.c Create Date:2022-07-29 10:48:08
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void fsnotify_put_mark(struct fsnotify_mark *mark)
{
    struct fsnotify_mark_connector *conn = READ_ONCE(mark->connector);
    void *objp = NULL;
    unsigned int type = FSNOTIFY_OBJ_TYPE_DETACHED;
    bool free_conn = false;
 
    /* Catch marks that were actually never attached to object */
    if (!conn) {
        if (refcount_dec_and_test(&mark->refcnt))
            fsnotify_final_mark_destroy(mark);
        return;
    }
 
    /*
     * We have to be careful so that traversals of obj_list under lock can
     * safely grab mark reference.
     */
    if (!refcount_dec_and_lock(&mark->refcnt, &conn->lock))
        return;
 
    hlist_del_init_rcu(&mark->obj_list);
    if (hlist_empty(&conn->list)) {
        objp = fsnotify_detach_connector_from_object(conn, &type);
        free_conn = true;
    } else {
        __fsnotify_recalc_mask(conn);
    }
    WRITE_ONCE(mark->connector, NULL);
    spin_unlock(&conn->lock);
 
    fsnotify_drop_object(type, objp);
 
    if (free_conn) {
        spin_lock(&destroy_lock);
        conn->destroy_next = connector_destroy_list;
        connector_destroy_list = conn;
        spin_unlock(&destroy_lock);
        queue_work(system_unbound_wq, &connector_reaper_work);
    }
    /*
     * Note that we didn't update flags telling whether inode cares about
     * what's happening with children. We update these flags from
     * __fsnotify_parent() lazily when next event happens on one of our
     * children.
     */
    spin_lock(&destroy_lock);
    list_add(&mark->g_list, &destroy_list);
    spin_unlock(&destroy_lock);
    queue_delayed_work(system_unbound_wq, &reaper_work,
               FSNOTIFY_REAPER_DELAY);
}