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authorChristoph Hellwig <hch@lst.de>2021-11-05 13:37:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 13:30:34 -0700
commitefee17134ca464639a2f5b4d036ce40caf1b247a (patch)
treeab0db78acebfe2bdbeb0cd3109523d10388f6e8e /mm/backing-dev.c
parent702f2d1e3b33617a8d9a9424f08a69b7c51642a7 (diff)
mm: simplify bdi refcounting
Move grabbing and releasing the bdi refcount out of the common wb_init/wb_exit helpers into code that is only used for the non-default memcg driven bdi_writeback structures. [hch@lst.de: add comment] Link: https://lkml.kernel.org/r/20211027074207.GA12793@lst.de [akpm@linux-foundation.org: fix typo] Link: https://lkml.kernel.org/r/20211021124441.668816-6-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Richard Weinberger <richard@nod.at> Cc: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r--mm/backing-dev.c13
1 files changed, 5 insertions, 8 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 768e9ae489f6..5ccb25089808 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -291,8 +291,6 @@ 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);
@@ -316,7 +314,7 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
err = fprop_local_init_percpu(&wb->completions, gfp);
if (err)
- goto out_put_bdi;
+ return err;
for (i = 0; i < NR_WB_STAT_ITEMS; i++) {
err = percpu_counter_init(&wb->stat[i], 0, gfp);
@@ -330,9 +328,6 @@ out_destroy_stat:
while (i--)
percpu_counter_destroy(&wb->stat[i]);
fprop_local_destroy_percpu(&wb->completions);
-out_put_bdi:
- if (wb != &bdi->wb)
- bdi_put(bdi);
return err;
}
@@ -373,8 +368,6 @@ static void wb_exit(struct bdi_writeback *wb)
percpu_counter_destroy(&wb->stat[i]);
fprop_local_destroy_percpu(&wb->completions);
- if (wb != &wb->bdi->wb)
- bdi_put(wb->bdi);
}
#ifdef CONFIG_CGROUP_WRITEBACK
@@ -397,6 +390,7 @@ static void cgwb_release_workfn(struct work_struct *work)
struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
release_work);
struct blkcg *blkcg = css_to_blkcg(wb->blkcg_css);
+ struct backing_dev_info *bdi = wb->bdi;
mutex_lock(&wb->bdi->cgwb_release_mutex);
wb_shutdown(wb);
@@ -416,6 +410,7 @@ static void cgwb_release_workfn(struct work_struct *work)
percpu_ref_exit(&wb->refcnt);
wb_exit(wb);
+ bdi_put(bdi);
WARN_ON_ONCE(!list_empty(&wb->b_attached));
kfree_rcu(wb, rcu);
}
@@ -497,6 +492,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
INIT_LIST_HEAD(&wb->b_attached);
INIT_WORK(&wb->release_work, cgwb_release_workfn);
set_bit(WB_registered, &wb->state);
+ bdi_get(bdi);
/*
* The root wb determines the registered state of the whole bdi and
@@ -528,6 +524,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
goto out_put;
err_fprop_exit:
+ bdi_put(bdi);
fprop_local_destroy_percpu(&wb->memcg_completions);
err_ref_exit:
percpu_ref_exit(&wb->refcnt);