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ceph: use READ_ONCE to access d_parent in RCU critical section 

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Yan, Zheng 2019-05-23 10:22:55 +08:00 committed by Ilya Dryomov
parent feab6ac25d
commit 41883ba8ee
1 changed files with 2 additions and 2 deletions
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4
fs/ceph/mds_client.c
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@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
struct inode *dir; struct inode *dir;
rcu_read_lock(); rcu_read_lock();
parent = req->r_dentry->d_parent; parent = READ_ONCE(req->r_dentry->d_parent);
dir = req->r_parent ? : d_inode_rcu(parent); dir = req->r_parent ? : d_inode_rcu(parent);
if (!dir || dir->i_sb != mdsc->fsc->sb) { if (!dir || dir->i_sb != mdsc->fsc->sb) {
@ -2145,7 +2145,7 @@ retry:
memcpy(path + pos, temp->d_name.name, temp->d_name.len); memcpy(path + pos, temp->d_name.name, temp->d_name.len);
} }
spin_unlock(&temp->d_lock); spin_unlock(&temp->d_lock);
temp = temp->d_parent; temp = READ_ONCE(temp->d_parent);
/* Are we at the root? */ /* Are we at the root? */
if (IS_ROOT(temp)) if (IS_ROOT(temp))