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-rw-r--r--mm/backing-dev.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 51cc461e7256..dac5bf59309d 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -425,7 +425,6 @@ retry:
new_congested = NULL;
rb_link_node(&congested->rb_node, parent, node);
rb_insert_color(&congested->rb_node, &bdi->cgwb_congested_tree);
- atomic_inc(&bdi->usage_cnt);
goto found;
}
@@ -456,7 +455,6 @@ found:
*/
void wb_congested_put(struct bdi_writeback_congested *congested)
{
- struct backing_dev_info *bdi = congested->bdi;
unsigned long flags;
local_irq_save(flags);
@@ -465,12 +463,15 @@ void wb_congested_put(struct bdi_writeback_congested *congested)
return;
}
- rb_erase(&congested->rb_node, &congested->bdi->cgwb_congested_tree);
+ /* bdi might already have been destroyed leaving @congested unlinked */
+ if (congested->bdi) {
+ rb_erase(&congested->rb_node,
+ &congested->bdi->cgwb_congested_tree);
+ congested->bdi = NULL;
+ }
+
spin_unlock_irqrestore(&cgwb_lock, flags);
kfree(congested);
-
- if (atomic_dec_and_test(&bdi->usage_cnt))
- wake_up_all(&cgwb_release_wait);
}
static void cgwb_release_workfn(struct work_struct *work)
@@ -675,13 +676,22 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi)
static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
{
struct radix_tree_iter iter;
+ struct bdi_writeback_congested *congested, *congested_n;
void **slot;
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);
+
+ rbtree_postorder_for_each_entry_safe(congested, congested_n,
+ &bdi->cgwb_congested_tree, rb_node) {
+ rb_erase(&congested->rb_node, &bdi->cgwb_congested_tree);
+ congested->bdi = NULL; /* mark @congested unlinked */
+ }
+
spin_unlock_irq(&cgwb_lock);
/*