Btrfs: improve error handling for btrfs_insert_dir_item callers

This allows us to gracefully continue if we aren't able to insert
directory items, both for normal files/dirs and snapshots.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

2 files changed, 26 insertions, 7 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6e0ee9b0d742..cbeb2e36cebc 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4585,7 +4585,8 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
                 ret = btrfs_insert_dir_item(trans, root, name, name_len,
                                             parent_inode, &key,
                                             btrfs_inode_type(inode), index);
-                BUG_ON(ret);
+                if (ret)
+                        goto fail_dir_item;
 
                 btrfs_i_size_write(parent_inode, parent_inode->i_size +
                                    name_len * 2);
@@ -4593,6 +4594,23 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
                 ret = btrfs_update_inode(trans, root, parent_inode);
         }
         return ret;
+
+fail_dir_item:
+        if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
+                u64 local_index;
+                int err;
+                err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
+                                 key.objectid, root->root_key.objectid,
+                                 parent_ino, &local_index, name, name_len);
+
+        } else if (add_backref) {
+                u64 local_index;
+                int err;
+
+                err = btrfs_del_inode_ref(trans, root, name, name_len,
+                                          ino, parent_ino, &local_index);
+        }
+        return ret;
 }
 
 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 287a6728b1ad..016977beee5c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -915,7 +915,11 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                                 dentry->d_name.name, dentry->d_name.len,
                                 parent_inode, &key,
                                 BTRFS_FT_DIR, index);
-        BUG_ON(ret);
+        if (ret) {
+                pending->error = -EEXIST;
+                dput(parent);
+                goto fail;
+        }
 
         btrfs_i_size_write(parent_inode, parent_inode->i_size +
                                          dentry->d_name.len * 2);
@@ -993,12 +997,9 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 {
         struct btrfs_pending_snapshot *pending;
         struct list_head *head = &trans->transaction->pending_snapshots;
-        int ret;
 
-        list_for_each_entry(pending, head, list) {
-                ret = create_pending_snapshot(trans, fs_info, pending);
-                BUG_ON(ret);
-        }
+        list_for_each_entry(pending, head, list)
+                create_pending_snapshot(trans, fs_info, pending);
         return 0;
 }