1 files changed, 7 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index bd70c2852ba0..064315990f8a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2508,6 +2508,13 @@ retry_root_backup:
         }
         fs_info->num_tolerated_disk_barrier_failures =
                 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
+        if (fs_info->fs_devices->missing_devices >
+             fs_info->num_tolerated_disk_barrier_failures &&
+            !(sb->s_flags & MS_RDONLY)) {
+                printk(KERN_WARNING
+                       "Btrfs: too many missing devices, writeable mount is not allowed\n");
+                goto fail_block_groups;
+        }
 
         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
                                                "btrfs-cleaner");