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authorLi Lingfeng <lilingfeng3@huawei.com>2023-12-29 15:05:00 +0800
committerSong Liu <song@kernel.org>2024-02-05 15:23:58 -0800
commit9cfcf99e7ed613e6b3697e1c1034a24487ec3154 (patch)
treec13b5cef52ef3e3bf9d144abe0b48e778aeb433c /drivers/md/md.c
parentfaeaf210a559eb05bc1a294082d100d01c49a1e9 (diff)
downloadlwn-9cfcf99e7ed613e6b3697e1c1034a24487ec3154.tar.gz
lwn-9cfcf99e7ed613e6b3697e1c1034a24487ec3154.zip
md: get rdev->mddev with READ_ONCE()
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. Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231229070500.3602712-1-lilingfeng@huaweicloud.com
Diffstat (limited to 'drivers/md/md.c')
-rw-r--r--drivers/md/md.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0b132ee2672e..5eff8e84cddf 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2591,7 +2591,7 @@ 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);
@@ -3664,7 +3664,7 @@ 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;