On 11/21/2017 11:58 AM, jeffm@suse.com wrote:

From: Jeff Mahoney jeffm@suse.com

Since commit fb235dc06fa (btrfs: qgroup: Move half of the qgroup accounting time out of commit trans) the assumption that btrfs_add_delayed_{data,tree}_ref can only return 0 or -ENOMEM has been false. The qgroup operations call into btrfs_search_slot and friends and can now return the full spectrum of error codes.

Fortunately, the fix here is easy since update_ref_for_cow failing is already handled so we just need to bail early with the error code.

Fixes: fb235dc06fa (btrfs: qgroup: Move half of the qgroup accounting ...) Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Jeff Mahoney jeffm@suse.com

Reviewed-by: Edmund Nadolski enadolski@suse.com

---

fs/btrfs/ctree.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 531e0a8645b0..1e74cf826532 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1032,14 +1032,17 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { ret = btrfs_inc_ref(trans, root, buf, 1);

• 	BUG_ON(ret); /* -ENOMEM */
  

• 	if (ret)
  

• 		return ret;
  

if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { ret = btrfs_dec_ref(trans, root, buf, 0);

• 		BUG_ON(ret); /* -ENOMEM */
  

• 		if (ret)
  

• 			return ret;
  	ret = btrfs_inc_ref(trans, root, cow, 1);
  

• 		BUG_ON(ret); /* -ENOMEM */
  

• 		if (ret)
  

• 			return ret;
  }
  new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
  

  } else {

@@ -1049,7 +1052,8 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, ret = btrfs_inc_ref(trans, root, cow, 1); else ret = btrfs_inc_ref(trans, root, cow, 0);

• 	BUG_ON(ret); /* -ENOMEM */
  

• 	if (ret)
  

• 		return ret;
  

  } if (new_flags != 0) { int level = btrfs_header_level(buf);

@@ -1068,9 +1072,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, ret = btrfs_inc_ref(trans, root, cow, 1); else ret = btrfs_inc_ref(trans, root, cow, 0);

• 	BUG_ON(ret); /* -ENOMEM */
  

• 	if (ret)
  

• 		return ret;
  ret = btrfs_dec_ref(trans, root, buf, 1);
  

• 	BUG_ON(ret); /* -ENOMEM */
  

• 	if (ret)
  

• 		return ret;
  

  } clean_tree_block(fs_info, buf); *last_ref = 1;