Messages in this thread | | | Subject | Re: [PATCH] md: get rdev->mddev with READ_ONCE() | From | Yu Kuai <> | Date | Tue, 2 Jan 2024 14:16:32 +0800 |
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在 2023/12/29 15:05, Li Lingfeng 写道: > From: Li Lingfeng <lilingfeng3@huawei.com> > > Users may get rdev->mddev by sysfs while rdev is releasing. > So use both READ_ONCE() and WRITE_ONCE() to prevent load/store tearing > and to read/write mddev atomically.
LGTM Reviewed-by: Yu Kuai <yukuai3@huawei.com> > > Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> > --- > drivers/md/md.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 9bdd57324c37..3b38a565bffa 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -2562,7 +2562,7 @@ static void md_kick_rdev_from_array(struct md_rdev *rdev) > list_del_rcu(&rdev->same_set); > pr_debug("md: unbind<%pg>\n", rdev->bdev); > mddev_destroy_serial_pool(rdev->mddev, rdev); > - rdev->mddev = NULL; > + WRITE_ONCE(rdev->mddev, NULL); > sysfs_remove_link(&rdev->kobj, "block"); > sysfs_put(rdev->sysfs_state); > sysfs_put(rdev->sysfs_unack_badblocks); > @@ -3646,7 +3646,7 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr, > struct kernfs_node *kn = NULL; > bool suspend = false; > ssize_t rv; > - struct mddev *mddev = rdev->mddev; > + struct mddev *mddev = READ_ONCE(rdev->mddev); > > if (!entry->store) > return -EIO; >
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