ceph: add a new flag to indicate whether parent is locked

struct ceph_mds_request has an r_locked_dir pointer, which is set to
indicate the parent inode and that its i_rwsem is locked.  In some
critical places, we need to be able to indicate the parent inode to the
request handling code, even when its i_rwsem may not be locked.

Most of the code that operates on r_locked_dir doesn't require that the
i_rwsem be locked. We only really need it to handle manipulation of the
dcache. The rest (filling of the inode, updating dentry leases, etc.)
already has its own locking.

Add a new r_req_flags bit that indicates whether the parent is locked
when doing the request, and rename the pointer to "r_parent". For now,
all the places that set r_parent also set this flag, but that will
change in a later patch.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Yan, Zheng <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index 180bbef760f2c..e8f11fa565c53 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -207,7 +207,8 @@ static int ceph_get_name(struct dentry *parent, char *name,
 	req->r_inode = d_inode(child);
 	ihold(d_inode(child));
 	req->r_ino2 = ceph_vino(d_inode(parent));
-	req->r_locked_dir = d_inode(parent);
+	req->r_parent = d_inode(parent);
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 	req->r_num_caps = 2;
 	err = ceph_mdsc_do_request(mdsc, NULL, req);