[PATCH 06/13] bdi: Make wb->bdi a proper reference
From: Jan Kara <jack@suse.cz>
Date: 2017-02-21 17:09:51
Subsystem:
memory management, memory management - misc, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
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@suse.cz> --- 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