From 692826b2738101549f032a761a9191636e83be4e Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Tue, 21 Nov 2017 13:58:49 -0500 Subject: [PATCH] btrfs: handle errors while updating refcounts in update_ref_for_cow 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: # v4.11+ Signed-off-by: Jeff Mahoney Reviewed-by: Edmund Nadolski Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- 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 531e0a8..1e74cf8 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; -- 2.7.4