ceph: fix dcache/nocache mount option

Signed-off-by: NYan, Zheng <zyan@redhat.com>

fs/ceph/dir.c

@@ -281,6 +281,7 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
 	/* can we use the dcache? */
 	spin_lock(&ci->i_ceph_lock);
 	if ((ctx->pos == 2 || fi->dentry) &&
+	    ceph_test_mount_opt(fsc, DCACHE) &&
 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
 	    ceph_snap(inode) != CEPH_SNAPDIR &&
 	    __ceph_dir_is_complete_ordered(ci) &&
@@ -629,6 +630,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 			    fsc->mount_options->snapdir_name,
 			    dentry->d_name.len) &&
 		    !is_root_ceph_dentry(dir, dentry) &&
+		    ceph_test_mount_opt(fsc, DCACHE) &&
 		    __ceph_dir_is_complete(ci) &&
 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
 			spin_unlock(&ci->i_ceph_lock);

fs/ceph/super.h

@@ -36,7 +36,8 @@
 #define CEPH_MOUNT_OPT_DCACHE          (1<<9) /* use dcache for readdir etc */
 #define CEPH_MOUNT_OPT_FSCACHE         (1<<10) /* use fscache */
 
-#define CEPH_MOUNT_OPT_DEFAULT    (CEPH_MOUNT_OPT_RBYTES)
+#define CEPH_MOUNT_OPT_DEFAULT    (CEPH_MOUNT_OPT_RBYTES | \
+				   CEPH_MOUNT_OPT_DCACHE)
 
 #define ceph_set_mount_opt(fsc, opt) \
 	(fsc)->mount_options->flags |= CEPH_MOUNT_OPT_##opt;