Make wb->bdi a proper refcounted reference to bdi for all bdi_writeback
structures except for the one embedded inside struct backing_dev_info.
That will allow us to simplify bdi unregistration.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
mm/backing-dev.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c324eae17f0d..d7aaf2517c30 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -294,6 +294,8 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
memset(wb, 0, sizeof(*wb));
+ if (wb != &bdi->wb)
+ bdi_get(bdi);
wb->bdi = bdi;
wb->last_old_flush = jiffies;
INIT_LIST_HEAD(&wb->b_dirty);
@@ -314,8 +316,10 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
wb->dirty_sleep = jiffies;
wb->congested = wb_congested_get_create(bdi, blkcg_id, gfp);
- if (!wb->congested)
- return -ENOMEM;
+ if (!wb->congested) {
+ err = -ENOMEM;
+ goto out_put_bdi;
+ }
err = fprop_local_init_percpu(&wb->completions, gfp);
if (err)
@@ -335,6 +339,9 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
fprop_local_destroy_percpu(&wb->completions);
out_put_cong:
wb_congested_put(wb->congested);
+out_put_bdi:
+ if (wb != &bdi->wb)
+ bdi_put(bdi);
return err;
}
@@ -372,6 +379,8 @@ static void wb_exit(struct bdi_writeback *wb)
fprop_local_destroy_percpu(&wb->completions);
wb_congested_put(wb->congested);
+ if (wb != &wb->bdi->wb)
+ bdi_put(wb->bdi);
}
#ifdef CONFIG_CGROUP_WRITEBACK
--
2.10.2
