btrfs: Use WARN_ON()'s return value in place of WARN_ON(1)

Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source
code that outputs a more descriptive warnings. Also fix the styling
warning of redundant braces that came up as a result of this fix.

Signed-off-by: Dulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

fs/btrfs/backref.c

@@ -326,8 +326,7 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 
 	eb = path->nodes[level];
 	while (!eb) {
-		if (!level) {
-			WARN_ON(1);
+		if (WARN_ON(!level)) {
 			ret = 1;
 			goto out;
 		}

fs/btrfs/check-integrity.c

@@ -2464,10 +2464,8 @@ static int btrfsic_process_written_superblock(
 		}
 	}
 
-	if (-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)) {
-		WARN_ON(1);
+	if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0)))
 		btrfsic_dump_tree(state);
-	}
 
 	return 0;
 }
@@ -2907,7 +2905,7 @@ static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
 		btrfsic_release_block_ctx(&block_ctx);
 	}
 
-	if (!match) {
+	if (WARN_ON(!match)) {
 		printk(KERN_INFO "btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio,"
 		       " buffer->log_bytenr=%llu, submit_bio(bdev=%s,"
 		       " phys_bytenr=%llu)!\n",
@@ -2924,7 +2922,6 @@ static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state,
 			       bytenr, block_ctx.dev->name,
 			       block_ctx.dev_bytenr, mirror_num);
 		}
-		WARN_ON(1);
 	}
 }
 

fs/btrfs/ctree.c

@@ -1285,11 +1285,10 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 		free_extent_buffer(eb_root);
 		blocksize = btrfs_level_size(root, old_root->level);
 		old = read_tree_block(root, logical, blocksize, 0);
-		if (!old || !extent_buffer_uptodate(old)) {
+		if (WARN_ON(!old || !extent_buffer_uptodate(old))) {
 			free_extent_buffer(old);
 			pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
 				logical);
-			WARN_ON(1);
 		} else {
 			eb = btrfs_clone_extent_buffer(old);
 			free_extent_buffer(old);
@@ -3643,8 +3642,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 		ret = 1;
 		goto out;
 	}
-	if (!empty && push_items == btrfs_header_nritems(right))
-		WARN_ON(1);
+	WARN_ON(!empty && push_items == btrfs_header_nritems(right));
 
 	/* push data from right to left */
 	copy_extent_buffer(left, right,

fs/btrfs/delayed-inode.c

@@ -649,14 +649,13 @@ static int btrfs_delayed_inode_reserve_metadata(
 			goto out;
 
 		ret = btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes);
-		if (!ret)
+		if (!WARN_ON(ret))
 			goto out;
 
 		/*
 		 * Ok this is a problem, let's just steal from the global rsv
 		 * since this really shouldn't happen that often.
 		 */
-		WARN_ON(1);
 		ret = btrfs_block_rsv_migrate(&root->fs_info->global_block_rsv,
 					      dst_rsv, num_bytes);
 		goto out;

fs/btrfs/disk-io.c

@@ -475,14 +475,8 @@ static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 	if (page != eb->pages[0])
 		return 0;
 	found_start = btrfs_header_bytenr(eb);
-	if (found_start != start) {
-		WARN_ON(1);
+	if (WARN_ON(found_start != start || !PageUptodate(page)))
 		return 0;
-	}
-	if (!PageUptodate(page)) {
-		WARN_ON(1);
-		return 0;
-	}
 	csum_tree_block(root, eb, 0);
 	return 0;
 }

fs/btrfs/extent-tree.c

@@ -1550,9 +1550,8 @@ again:
 	if (ret && !insert) {
 		err = -ENOENT;
 		goto out;
-	} else if (ret) {
+	} else if (WARN_ON(ret)) {
 		err = -EIO;
-		WARN_ON(1);
 		goto out;
 	}
 
@@ -5752,9 +5751,8 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			}
 			extent_slot = path->slots[0];
 		}
-	} else if (ret == -ENOENT) {
+	} else if (WARN_ON(ret == -ENOENT)) {
 		btrfs_print_leaf(extent_root, path->nodes[0]);
-		WARN_ON(1);
 		btrfs_err(info,
 			"unable to find ref byte nr %llu parent %llu root %llu  owner %llu offset %llu",
 			bytenr, parent, root_objectid, owner_objectid,
@@ -8317,10 +8315,9 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 					struct btrfs_space_info,
 					list);
 		if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
-			if (space_info->bytes_pinned > 0 ||
+			if (WARN_ON(space_info->bytes_pinned > 0 ||
 			    space_info->bytes_reserved > 0 ||
-			    space_info->bytes_may_use > 0) {
-				WARN_ON(1);
+			    space_info->bytes_may_use > 0)) {
 				dump_space_info(space_info, 0, 0);
 			}
 		}

fs/btrfs/extent_io.c

@@ -1739,10 +1739,8 @@ u64 count_range_bits(struct extent_io_tree *tree,
 	u64 last = 0;
 	int found = 0;
 
-	if (search_end <= cur_start) {
-		WARN_ON(1);
+	if (WARN_ON(search_end <= cur_start))
 		return 0;
-	}
 
 	spin_lock(&tree->lock);
 	if (cur_start == 0 && bits == EXTENT_DIRTY) {
@@ -3568,9 +3566,8 @@ retry:
 			 * but no sense in crashing the users box for something
 			 * we can survive anyway.
 			 */
-			if (!eb) {
+			if (WARN_ON(!eb)) {
 				spin_unlock(&mapping->private_lock);
-				WARN_ON(1);
 				continue;
 			}
 

fs/btrfs/file-item.c

@@ -849,10 +849,8 @@ insert:
 	path->leave_spinning = 0;
 	if (ret < 0)
 		goto fail_unlock;
-	if (ret != 0) {
-		WARN_ON(1);
+	if (WARN_ON(ret != 0))
 		goto fail_unlock;
-	}
 	leaf = path->nodes[0];
 csum:
 	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);

fs/btrfs/inode-map.c

@@ -78,10 +78,8 @@ again:
 			    btrfs_transaction_in_commit(fs_info)) {
 				leaf = path->nodes[0];
 
-				if (btrfs_header_nritems(leaf) == 0) {
-					WARN_ON(1);
+				if (WARN_ON(btrfs_header_nritems(leaf) == 0))
 					break;
-				}
 
 				/*
 				 * Save the key so we can advances forward

fs/btrfs/inode.c

@@ -2039,10 +2039,8 @@ static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
 		key.offset = offset;
 
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	if (ret < 0) {
-		WARN_ON(1);
+	if (WARN_ON(ret < 0))
 		return ret;
-	}
 	ret = 0;
 
 	while (1) {
@@ -3182,8 +3180,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 
 		/* if we have links, this was a truncate, lets do that */
 		if (inode->i_nlink) {
-			if (!S_ISREG(inode->i_mode)) {
-				WARN_ON(1);
+			if (WARN_ON(!S_ISREG(inode->i_mode))) {
 				iput(inode);
 				continue;
 			}
@@ -8023,8 +8020,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		if (ret == -EEXIST) {
 			/* we shouldn't get
 			 * eexist without a new_inode */
-			if (!new_inode) {
-				WARN_ON(1);
+			if (WARN_ON(!new_inode)) {
 				return ret;
 			}
 		} else {

fs/btrfs/relocation.c

@@ -1777,8 +1777,7 @@ again:
 			new_ptr_gen = 0;
 		}
 
-		if (new_bytenr > 0 && new_bytenr == old_bytenr) {
-			WARN_ON(1);
+		if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
 			ret = level;
 			break;
 		}
@@ -3545,10 +3544,8 @@ static int find_data_references(struct reloc_control *rc,
 				err = ret;
 				goto out;
 			}
-			if (ret > 0) {
-				WARN_ON(1);
+			if (WARN_ON(ret > 0))
 				goto out;
-			}
 
 			leaf = path->nodes[0];
 			nritems = btrfs_header_nritems(leaf);
@@ -3568,11 +3565,9 @@ static int find_data_references(struct reloc_control *rc,
 		}
 
 		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-		if (key.objectid != ref_objectid ||
-		    key.type != BTRFS_EXTENT_DATA_KEY) {
-			WARN_ON(1);
+		if (WARN_ON(key.objectid != ref_objectid ||
+		    key.type != BTRFS_EXTENT_DATA_KEY))
 			break;
-		}
 
 		fi = btrfs_item_ptr(leaf, path->slots[0],
 				    struct btrfs_file_extent_item);

fs/btrfs/send.c

@@ -564,10 +564,8 @@ static int begin_cmd(struct send_ctx *sctx, int cmd)
 {
 	struct btrfs_cmd_header *hdr;
 
-	if (!sctx->send_buf) {
-		WARN_ON(1);
+	if (WARN_ON(!sctx->send_buf))
 		return -EINVAL;
-	}
 
 	BUG_ON(sctx->send_size);
 

fs/btrfs/tree-log.c

@@ -2130,8 +2130,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 		WARN_ON(*level >= BTRFS_MAX_LEVEL);
 		cur = path->nodes[*level];
 
-		if (btrfs_header_level(cur) != *level)
-			WARN_ON(1);
+		WARN_ON(btrfs_header_level(cur) != *level);
 
 		if (path->slots[*level] >=
 		    btrfs_header_nritems(cur))
@@ -2951,10 +2950,8 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
 
 	/* find the first key from this transaction again */
 	ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
-	if (ret != 0) {
-		WARN_ON(1);
+	if (WARN_ON(ret != 0))
 		goto done;
-	}
 
 	/*
 	 * we have a block from this transaction, log every item in it

fs/btrfs/volumes.c

@@ -2552,8 +2552,7 @@ again:
 		failed = 0;
 		retried = true;
 		goto again;
-	} else if (failed && retried) {
-		WARN_ON(1);
+	} else if (WARN_ON(failed && retried)) {
 		ret = -ENOSPC;
 	}
 error:
@@ -5402,10 +5401,8 @@ static int bio_size_ok(struct block_device *bdev, struct bio *bio,
 		.bi_rw = bio->bi_rw,
 	};
 
-	if (bio->bi_vcnt == 0) {
-		WARN_ON(1);
+	if (WARN_ON(bio->bi_vcnt == 0))
 		return 1;
-	}
 
 	prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
 	if (bio_sectors(bio) > max_sectors)
@@ -5638,10 +5635,8 @@ struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 	struct btrfs_device *dev;
 	u64 tmp;
 
-	if (!devid && !fs_info) {
-		WARN_ON(1);
+	if (WARN_ON(!devid && !fs_info))
 		return ERR_PTR(-EINVAL);
-	}
 
 	dev = __alloc_device();
 	if (IS_ERR(dev))