diff options
| -rw-r--r-- | mm/backing-dev.c | 90 |
1 files changed, 23 insertions, 67 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 52e0c7652448..1725adb242e0 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -37,17 +37,6 @@ LIST_HEAD(bdi_list); /* bdi_wq serves all asynchronous writeback tasks */ struct workqueue_struct *bdi_wq; -static void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2) -{ - if (wb1 < wb2) { - spin_lock(&wb1->list_lock); - spin_lock_nested(&wb2->list_lock, 1); - } else { - spin_lock(&wb2->list_lock); - spin_lock_nested(&wb1->list_lock, 1); - } -} - #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #include <linux/seq_file.h> @@ -352,19 +341,19 @@ EXPORT_SYMBOL(bdi_register_dev); */ static void bdi_wb_shutdown(struct backing_dev_info *bdi) { - if (!bdi_cap_writeback_dirty(bdi)) + /* Make sure nobody queues further work */ + spin_lock_bh(&bdi->wb_lock); + if (!test_and_clear_bit(BDI_registered, &bdi->state)) { + spin_unlock_bh(&bdi->wb_lock); return; + } + spin_unlock_bh(&bdi->wb_lock); /* * Make sure nobody finds us on the bdi_list anymore */ bdi_remove_from_list(bdi); - /* Make sure nobody queues further work */ - spin_lock_bh(&bdi->wb_lock); - clear_bit(BDI_registered, &bdi->state); - spin_unlock_bh(&bdi->wb_lock); - /* * Drain work list and shutdown the delayed_work. At this point, * @bdi->bdi_list is empty telling bdi_Writeback_workfn() that @bdi @@ -372,37 +361,22 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi) */ mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0); flush_delayed_work(&bdi->wb.dwork); - WARN_ON(!list_empty(&bdi->work_list)); - WARN_ON(delayed_work_pending(&bdi->wb.dwork)); } /* - * This bdi is going away now, make sure that no super_blocks point to it + * Called when the device behind @bdi has been removed or ejected. + * + * We can't really do much here except for reducing the dirty ratio at + * the moment. In the future we should be able to set a flag so that + * the filesystem can handle errors at mark_inode_dirty time instead + * of only at writeback time. */ -static void bdi_prune_sb(struct backing_dev_info *bdi) -{ - struct super_block *sb; - - spin_lock(&sb_lock); - list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_bdi == bdi) - sb->s_bdi = &default_backing_dev_info; - } - spin_unlock(&sb_lock); -} - void bdi_unregister(struct backing_dev_info *bdi) { - if (bdi->dev) { - bdi_set_min_ratio(bdi, 0); - trace_writeback_bdi_unregister(bdi); - bdi_prune_sb(bdi); + if (WARN_ON_ONCE(!bdi->dev)) + return; - bdi_wb_shutdown(bdi); - bdi_debug_unregister(bdi); - device_unregister(bdi->dev); - bdi->dev = NULL; - } + bdi_set_min_ratio(bdi, 0); } EXPORT_SYMBOL(bdi_unregister); @@ -471,37 +445,19 @@ void bdi_destroy(struct backing_dev_info *bdi) { int i; - /* - * Splice our entries to the default_backing_dev_info. This - * condition shouldn't happen. @wb must be empty at this point and - * dirty inodes on it might cause other issues. This workaround is - * added by ce5f8e779519 ("writeback: splice dirty inode entries to - * default bdi on bdi_destroy()") without root-causing the issue. - * - * http://lkml.kernel.org/g/1253038617-30204-11-git-send-email-jens.axboe@oracle.com - * http://thread.gmane.org/gmane.linux.file-systems/35341/focus=35350 - * - * We should probably add WARN_ON() to find out whether it still - * happens and track it down if so. - */ - if (bdi_has_dirty_io(bdi)) { - struct bdi_writeback *dst = &default_backing_dev_info.wb; - - bdi_lock_two(&bdi->wb, dst); - list_splice(&bdi->wb.b_dirty, &dst->b_dirty); - list_splice(&bdi->wb.b_io, &dst->b_io); - list_splice(&bdi->wb.b_more_io, &dst->b_more_io); - spin_unlock(&bdi->wb.list_lock); - spin_unlock(&dst->list_lock); - } - - bdi_unregister(bdi); + bdi_wb_shutdown(bdi); + WARN_ON(!list_empty(&bdi->work_list)); WARN_ON(delayed_work_pending(&bdi->wb.dwork)); + if (bdi->dev) { + bdi_debug_unregister(bdi); + device_unregister(bdi->dev); + bdi->dev = NULL; + } + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) percpu_counter_destroy(&bdi->bdi_stat[i]); - fprop_local_destroy_percpu(&bdi->completions); } EXPORT_SYMBOL(bdi_destroy); |