diff options
| -rw-r--r-- | include/linux/backing-dev-defs.h | 1 | ||||
| -rw-r--r-- | mm/backing-dev.c | 22 |
2 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 8fb3dcdebc80..8af720f22a2d 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -21,6 +21,7 @@ struct dentry; */ enum wb_state { WB_registered, /* bdi_register() was done */ + WB_shutting_down, /* wb_shutdown() in progress */ WB_writeback_running, /* Writeback is in progress */ WB_has_dirty_io, /* Dirty inodes on ->b_{dirty|io|more_io} */ }; diff --git a/mm/backing-dev.c b/mm/backing-dev.c index e3d56dba4da8..b67be4fc12c4 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -356,8 +356,15 @@ static void wb_shutdown(struct bdi_writeback *wb) spin_lock_bh(&wb->work_lock); if (!test_and_clear_bit(WB_registered, &wb->state)) { spin_unlock_bh(&wb->work_lock); + /* + * Wait for wb shutdown to finish if someone else is just + * running wb_shutdown(). Otherwise we could proceed to wb / + * bdi destruction before wb_shutdown() is finished. + */ + wait_on_bit(&wb->state, WB_shutting_down, TASK_UNINTERRUPTIBLE); return; } + set_bit(WB_shutting_down, &wb->state); spin_unlock_bh(&wb->work_lock); cgwb_remove_from_bdi_list(wb); @@ -369,6 +376,12 @@ static void wb_shutdown(struct bdi_writeback *wb) mod_delayed_work(bdi_wq, &wb->dwork, 0); flush_delayed_work(&wb->dwork); WARN_ON(!list_empty(&wb->work_list)); + /* + * Make sure bit gets cleared after shutdown is finished. Matches with + * the barrier provided by test_and_clear_bit() above. + */ + smp_wmb(); + clear_bit(WB_shutting_down, &wb->state); } static void wb_exit(struct bdi_writeback *wb) @@ -699,12 +712,21 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { struct radix_tree_iter iter; void **slot; + struct bdi_writeback *wb; WARN_ON(test_bit(WB_registered, &bdi->wb.state)); spin_lock_irq(&cgwb_lock); radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) cgwb_kill(*slot); + + while (!list_empty(&bdi->wb_list)) { + wb = list_first_entry(&bdi->wb_list, struct bdi_writeback, + bdi_node); + spin_unlock_irq(&cgwb_lock); + wb_shutdown(wb); + spin_lock_irq(&cgwb_lock); + } spin_unlock_irq(&cgwb_lock); /* |