LU-16958 llite: migrate vs regular ops deadlock

[fs/lustre-release.git] / lustre / lov / lov_object.c

diff --git a/lustre/lov/lov_object.c b/lustre/lov/lov_object.c
index 16f4bf6..023c348 100644 (file)
--- a/lustre/lov/lov_object.c
+++ b/lustre/lov/lov_object.c
@@ -1369,6 +1369,7 @@ static int lov_conf_set(const struct lu_env *env, struct cl_object *obj,
        struct cl_object *top = cl_object_top(obj);
        bool unlock_inode = false;
        bool lock_inode_size = false;
+       bool lock_layout = false;
        ENTRY;
 
        if (conf->coc_opc == OBJECT_CONF_SET &&
@@ -1440,11 +1441,12 @@ retry:
                        /**
                         * we need unlocked lov conf and get inode lock.
                         * It's possible we have already taken inode's size
-                        * mutex, so we need keep such lock order, lest deadlock
-                        * happens:
-                        *   inode lock       (ll_inode_lock())
-                        *   inode size lock  (ll_inode_size_lock())
-                        *   lov conf lock    (lov_conf_lock())
+                        * mutex and/or layout mutex, so we need keep such lock
+                        * order, lest deadlock happens:
+                        *   inode lock        (ll_inode_lock())
+                        *   inode size lock   (ll_inode_size_lock())
+                        *   inode layout lock (ll_layout_refresh())
+                        *   lov conf lock     (lov_conf_lock())
                         *
                         * e.g.
                         *   vfs_setxattr                inode locked
@@ -1453,10 +1455,20 @@ retry:
                         *         ll_file_inode_init
                         *           cl_conf_set
                         *             lov_conf_set      lov conf locked
+                        *
+                        *   ll_migrate                  inode locked
+                        *     ...
+                        *       ll_layout_refresh       inode layout locked
+                        *         ll_layout_conf
+                        *           cl_conf_set
+                        *             lov_conf_set      lov conf locked
                         */
                        lov_conf_unlock(lov);
-                       if (cl_object_inode_ops(
-                                       env, top, COIO_SIZE_UNLOCK, NULL) == 0)
+                       if (cl_object_inode_ops(env, top, COIO_LAYOUT_UNLOCK,
+                                               NULL) == 0)
+                               lock_layout = true;
+                       if (cl_object_inode_ops(env, top, COIO_SIZE_UNLOCK,
+                                               NULL) == 0)
                                lock_inode_size = true;
 
                        /* take lock in order */
@@ -1464,8 +1476,11 @@ retry:
                                        env, top, COIO_INODE_LOCK, NULL) == 0)
                                unlock_inode = true;
                        if (lock_inode_size)
-                               cl_object_inode_ops(
-                                       env, top, COIO_SIZE_LOCK, NULL);
+                               cl_object_inode_ops(env, top, COIO_SIZE_LOCK,
+                                                   NULL);
+                       if (lock_layout)
+                               cl_object_inode_ops(env, top, COIO_LAYOUT_LOCK,
+                                                   NULL);
                        goto retry;
                }
                set_bit(LO_LAYOUT_INVALID, &lov->lo_obj_flags);