+/* The first part of oxe_buf is xattr name, and is '\0' terminated.
+ * The left part is for value, binary mode. */
+struct osd_xattr_entry {
+ struct list_head oxe_list;
+ size_t oxe_len;
+ size_t oxe_namelen;
+ bool oxe_exist;
+ struct rcu_head oxe_rcu;
+ char oxe_buf[0];
+};
+
+static struct osd_xattr_entry *osd_oxc_lookup(struct osd_object *obj,
+ const char *name,
+ size_t namelen)
+{
+ struct osd_xattr_entry *oxe;
+
+ list_for_each_entry(oxe, &obj->oo_xattr_list, oxe_list) {
+ if (namelen == oxe->oxe_namelen &&
+ strncmp(name, oxe->oxe_buf, namelen) == 0)
+ return oxe;
+ }
+
+ return NULL;
+}
+
+static int osd_oxc_get(struct osd_object *obj, const char *name,
+ struct lu_buf *buf)
+{
+ struct osd_xattr_entry *oxe;
+ size_t vallen;
+ ENTRY;
+
+ rcu_read_lock();
+ oxe = osd_oxc_lookup(obj, name, strlen(name));
+ if (oxe == NULL) {
+ rcu_read_unlock();
+ RETURN(-ENOENT);
+ }
+
+ if (!oxe->oxe_exist) {
+ rcu_read_unlock();
+ RETURN(-ENODATA);
+ }
+
+ vallen = oxe->oxe_len - sizeof(*oxe) - oxe->oxe_namelen - 1;
+ LASSERT(vallen > 0);
+
+ if (buf->lb_buf == NULL) {
+ rcu_read_unlock();
+ RETURN(vallen);
+ }
+
+ if (buf->lb_len < vallen) {
+ rcu_read_unlock();
+ RETURN(-ERANGE);
+ }
+
+ memcpy(buf->lb_buf, oxe->oxe_buf + oxe->oxe_namelen + 1, vallen);
+ rcu_read_unlock();
+
+ RETURN(vallen);
+}
+
+static void osd_oxc_free(struct rcu_head *head)
+{
+ struct osd_xattr_entry *oxe;
+
+ oxe = container_of(head, struct osd_xattr_entry, oxe_rcu);
+ OBD_FREE(oxe, oxe->oxe_len);
+}
+
+static inline void __osd_oxc_del(struct osd_object *obj, const char *name)
+{
+ struct osd_xattr_entry *oxe;
+
+ oxe = osd_oxc_lookup(obj, name, strlen(name));
+ if (oxe != NULL) {
+ list_del(&oxe->oxe_list);
+ call_rcu(&oxe->oxe_rcu, osd_oxc_free);
+ }
+}
+
+static void osd_oxc_add(struct osd_object *obj, const char *name,
+ const char *buf, int buflen)
+{
+ struct osd_xattr_entry *oxe;
+ size_t namelen = strlen(name);
+ size_t len = sizeof(*oxe) + namelen + 1 + buflen;
+
+ OBD_ALLOC(oxe, len);
+ if (oxe == NULL)
+ return;
+
+ INIT_LIST_HEAD(&oxe->oxe_list);
+ oxe->oxe_len = len;
+ oxe->oxe_namelen = namelen;
+ memcpy(oxe->oxe_buf, name, namelen);
+ if (buflen > 0) {
+ LASSERT(buf != NULL);
+ memcpy(oxe->oxe_buf + namelen + 1, buf, buflen);
+ oxe->oxe_exist = true;
+ } else {
+ oxe->oxe_exist = false;
+ }
+
+ /* this should be rarely called, just remove old and add new */
+ spin_lock(&obj->oo_guard);
+ __osd_oxc_del(obj, name);
+ list_add_tail(&oxe->oxe_list, &obj->oo_xattr_list);
+ spin_unlock(&obj->oo_guard);
+}
+
+static void osd_oxc_del(struct osd_object *obj, const char *name)
+{
+ spin_lock(&obj->oo_guard);
+ __osd_oxc_del(obj, name);
+ spin_unlock(&obj->oo_guard);
+}
+
+static void osd_oxc_fini(struct osd_object *obj)
+{
+ struct osd_xattr_entry *oxe, *next;
+
+ list_for_each_entry_safe(oxe, next, &obj->oo_xattr_list, oxe_list) {
+ list_del(&oxe->oxe_list);
+ OBD_FREE(oxe, oxe->oxe_len);
+ }
+}
+