On Thu, 2019-05-23 at 16:13 +0800, Yan, Zheng wrote:
> Signed-off-by: "Yan, Zheng" <zyan@xxxxxxxxxx>
> ---
> fs/ceph/mds_client.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 60e8ddbdfdc5..870754e9d572 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
> struct inode *dir;
>
> rcu_read_lock();
> - parent = req->r_dentry->d_parent;
> + parent = READ_ONCE(req->r_dentry->d_parent);
Can we use rcu_dereference() instead?
> dir = req->r_parent ? : d_inode_rcu(parent);
>
> if (!dir || dir->i_sb != mdsc->fsc->sb) {
> @@ -2131,8 +2131,8 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
> if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
> dout("build_path path+%d: %p SNAPDIR\n",
> pos, temp);
> - } else if (stop_on_nosnap && inode && dentry != temp &&
> - ceph_snap(inode) == CEPH_NOSNAP) {
> + } else if (stop_on_nosnap && dentry != temp &&
> + inode && ceph_snap(inode) == CEPH_NOSNAP) {
^^^ Unrelated delta?
> spin_unlock(&temp->d_lock);
> pos++; /* get rid of any prepended '/' */
> break;
> @@ -2145,7 +2145,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
> memcpy(path + pos, temp->d_name.name, temp->d_name.len);
> }
> spin_unlock(&temp->d_lock);
> - temp = temp->d_parent;
> + temp = READ_ONCE(temp->d_parent);
Better to use rcu_dereference() here.
>
> /* Are we at the root? */
> if (IS_ROOT(temp))
--
Jeff Layton <jlayton@xxxxxxxxxx>
