1 files changed, 10 insertions, 21 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index dbc66815a0fe..672c17bb32db 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -331,7 +331,7 @@ static int bdi_forker_thread(void *ptr)
         for (;;) {
                 bool fork = false;
                 struct task_struct *task;
-                struct backing_dev_info *bdi, *tmp;
+                struct backing_dev_info *bdi;
 
                 /*
                  * Temporary measure, we want to make sure we don't see
@@ -347,7 +347,7 @@ static int bdi_forker_thread(void *ptr)
                  * Check if any existing bdi's have dirty data without
                  * a thread registered. If so, set that up.
                  */
-                list_for_each_entry_safe(bdi, tmp, &bdi_list, bdi_list) {
+                list_for_each_entry(bdi, &bdi_list, bdi_list) {
                         if (!bdi_cap_writeback_dirty(bdi))
                                 continue;
                         if (bdi->wb.task)
@@ -359,8 +359,13 @@ static int bdi_forker_thread(void *ptr)
                         WARN(!test_bit(BDI_registered, &bdi->state),
                              "bdi %p/%s is not registered!\n", bdi, bdi->name);
 
-                        list_del_rcu(&bdi->bdi_list);
                         fork = true;
+
+                        /*
+                         * Set the pending bit - if someone will try to
+                         * unregister this bdi - it'll wait on this bit.
+                         */
+                        set_bit(BDI_pending, &bdi->state);
                         break;
                 }
                 spin_unlock_bh(&bdi_lock);
@@ -383,29 +388,13 @@ static int bdi_forker_thread(void *ptr)
 
                 __set_current_state(TASK_RUNNING);
 
-                /*
-                 * Set the pending bit - if someone will try to unregister this
-                 * bdi - it'll wait on this bit.
-                 */
-                set_bit(BDI_pending, &bdi->state);
-
-                /* Make sure no one uses the picked bdi */
-                synchronize_rcu();
-
                 task = kthread_run(bdi_writeback_thread, &bdi->wb, "flush-%s",
                                    dev_name(bdi->dev));
                 if (IS_ERR(task)) {
                         /*
-                         * If thread creation fails, then readd the bdi back to
-                         * the list and force writeout of the bdi from this
-                         * forker thread. That will free some memory and we can
-                         * try again. Add it to the tail so we get a chance to
-                         * flush other bdi's to free memory.
+                         * If thread creation fails, force writeout of the bdi
+                         * from the thread.
                          */
-                        spin_lock_bh(&bdi_lock);
-                        list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
-                        spin_unlock_bh(&bdi_lock);
-
                         bdi_flush_io(bdi);
                 } else
                         bdi->wb.task = task;