btrfs: move btrfs_check_trunc_cache_free_space into block-rsv.c

This is completely related to block rsv's, move it out of the free space
cache code and into block-rsv.c.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/block-rsv.c

@@ -541,3 +541,22 @@ struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
 
 	return ERR_PTR(ret);
 }
+
+int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
+				       struct btrfs_block_rsv *rsv)
+{
+	u64 needed_bytes;
+	int ret;
+
+	/* 1 for slack space, 1 for updating the inode */
+	needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
+		btrfs_calc_metadata_size(fs_info, 1);
+
+	spin_lock(&rsv->lock);
+	if (rsv->reserved < needed_bytes)
+		ret = -ENOSPC;
+	else
+		ret = 0;
+	spin_unlock(&rsv->lock);
+	return ret;
+}

fs/btrfs/block-rsv.h

@@ -82,6 +82,8 @@ void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
 struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
 					    struct btrfs_root *root,
 					    u32 blocksize);
+int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
+				       struct btrfs_block_rsv *rsv);
 static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
 					 struct btrfs_block_rsv *block_rsv,
 					 u32 blocksize)

fs/btrfs/free-space-cache.c

@@ -292,25 +292,6 @@ int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
-				       struct btrfs_block_rsv *rsv)
-{
-	u64 needed_bytes;
-	int ret;
-
-	/* 1 for slack space, 1 for updating the inode */
-	needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
-		btrfs_calc_metadata_size(fs_info, 1);
-
-	spin_lock(&rsv->lock);
-	if (rsv->reserved < needed_bytes)
-		ret = -ENOSPC;
-	else
-		ret = 0;
-	spin_unlock(&rsv->lock);
-	return ret;
-}
-
 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct btrfs_block_group *block_group,
 				    struct inode *vfs_inode)

fs/btrfs/free-space-cache.h

@@ -101,8 +101,6 @@ int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
 				  struct inode *inode,
 				  struct btrfs_block_group *block_group);
 
-int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
-				       struct btrfs_block_rsv *rsv);
 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct btrfs_block_group *block_group,
 				    struct inode *inode);