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Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r--mm/backing-dev.c40
1 files changed, 16 insertions, 24 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 12a992b62576..0ae0df55000b 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -40,7 +40,7 @@ LIST_HEAD(bdi_list);
/* bdi_wq serves all asynchronous writeback tasks */
struct workqueue_struct *bdi_wq;
-void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
+static void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
{
if (wb1 < wb2) {
spin_lock(&wb1->list_lock);
@@ -376,13 +376,7 @@ 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));
-
- /*
- * This shouldn't be necessary unless @bdi for some reason has
- * unflushed dirty IO after work_list is drained. Do it anyway
- * just in case.
- */
- cancel_delayed_work_sync(&bdi->wb.dwork);
+ WARN_ON(delayed_work_pending(&bdi->wb.dwork));
}
/*
@@ -402,21 +396,15 @@ static void bdi_prune_sb(struct backing_dev_info *bdi)
void bdi_unregister(struct backing_dev_info *bdi)
{
- struct device *dev = bdi->dev;
-
- if (dev) {
+ if (bdi->dev) {
bdi_set_min_ratio(bdi, 0);
trace_writeback_bdi_unregister(bdi);
bdi_prune_sb(bdi);
bdi_wb_shutdown(bdi);
bdi_debug_unregister(bdi);
-
- spin_lock_bh(&bdi->wb_lock);
+ device_unregister(bdi->dev);
bdi->dev = NULL;
- spin_unlock_bh(&bdi->wb_lock);
-
- device_unregister(dev);
}
}
EXPORT_SYMBOL(bdi_unregister);
@@ -487,8 +475,17 @@ void bdi_destroy(struct backing_dev_info *bdi)
int i;
/*
- * Splice our entries to the default_backing_dev_info, if this
- * bdi disappears
+ * 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;
@@ -503,12 +500,7 @@ void bdi_destroy(struct backing_dev_info *bdi)
bdi_unregister(bdi);
- /*
- * If bdi_unregister() had already been called earlier, the dwork
- * could still be pending because bdi_prune_sb() can race with the
- * bdi_wakeup_thread_delayed() calls from __mark_inode_dirty().
- */
- cancel_delayed_work_sync(&bdi->wb.dwork);
+ WARN_ON(delayed_work_pending(&bdi->wb.dwork));
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
percpu_counter_destroy(&bdi->bdi_stat[i]);