nfs4_get_open_state
extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
ctx->state = nfs4_get_open_state(r_ino, sp);
state = nfs4_get_open_state(inode, data->owner);
opendata->state = nfs4_get_open_state(d_inode(dentry), sp);