ceph: make 'nocopyfrom' a default mount option

Since we found a problem with the 'copy-from' operation after objects have
been truncated, offloading object copies to OSDs should be discouraged
until the issue is fixed.

Thus, this patch adds the 'nocopyfrom' mount option to the default mount
options which effectily means that remote copies won't be done in
copy_file_range unless they are explicitly enabled at mount time.

[ Adjust ceph_show_options() accordingly. ]

Link: https://tracker.ceph.com/issues/37378
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/super.c

@@ -563,8 +563,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
 		seq_puts(m, ",noacl");
 #endif
 
-	if (fsopt->flags & CEPH_MOUNT_OPT_NOCOPYFROM)
-		seq_puts(m, ",nocopyfrom");
+	if ((fsopt->flags & CEPH_MOUNT_OPT_NOCOPYFROM) == 0)
+		seq_puts(m, ",copyfrom");
 
 	if (fsopt->mds_namespace)
 		seq_show_option(m, "mds_namespace", fsopt->mds_namespace);

fs/ceph/super.h

@@ -42,7 +42,9 @@
 #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */
 #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */
 
-#define CEPH_MOUNT_OPT_DEFAULT    CEPH_MOUNT_OPT_DCACHE
+#define CEPH_MOUNT_OPT_DEFAULT			\
+	(CEPH_MOUNT_OPT_DCACHE |		\
+	 CEPH_MOUNT_OPT_NOCOPYFROM)
 
 #define ceph_set_mount_opt(fsc, opt) \
 	(fsc)->mount_options->flags |= CEPH_MOUNT_OPT_##opt;