ceph: hold extra reference to r_parent over life of request

Currently, we just assume that it will stick around by virtue of the
submitter's reference, but later patches will allow the syscall to
return early and we can't rely on that reference at that point.

Take an extra reference to the inode when setting r_parent and release
it when releasing the request.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index d379f489ab63282fb3d13ff8df1164350c59f356..011c779e4c767f732118bea38e46bee29d69b8c7 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -709,8 +709,10 @@ void ceph_mdsc_release_request(struct kref *kref)
                /* avoid calling iput_final() in mds dispatch threads */
                ceph_async_iput(req->r_inode);
        }
-       if (req->r_parent)
+       if (req->r_parent) {
                ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
+               ceph_async_iput(req->r_parent);
+       }
        ceph_async_iput(req->r_target_inode);
        if (req->r_dentry)
                dput(req->r_dentry);
@@ -2714,8 +2716,10 @@ int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
        /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
        if (req->r_inode)
                ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
-       if (req->r_parent)
+       if (req->r_parent) {
                ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
+               ihold(req->r_parent);
+       }
        if (req->r_old_dentry_dir)
                ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
                                  CEPH_CAP_PIN);