btrfs: get fs_info from block group in lookup_free_space_inode

We can read fs_info from the block group cache structure and can drop it
from the parameters.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -3312,7 +3312,7 @@ static int cache_save_setup(struct btrfs_block_group_cache *block_group,
 	if (trans->aborted)
 		return 0;
 again:
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	inode = lookup_free_space_inode(block_group, path);
 	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
 		ret = PTR_ERR(inode);
 		btrfs_release_path(path);
@@ -10699,7 +10699,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	 * get the inode first so any iput calls done for the io_list
 	 * aren't the final iput (no unlinks allowed now)
 	 */
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	inode = lookup_free_space_inode(block_group, path);
 
 	mutex_lock(&trans->transaction->cache_write_mutex);
 	/*

fs/btrfs/free-space-cache.c

@@ -88,10 +88,11 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 	return inode;
 }
 
-struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
-				      struct btrfs_block_group_cache
-				      *block_group, struct btrfs_path *path)
+struct inode *lookup_free_space_inode(
+		struct btrfs_block_group_cache *block_group,
+		struct btrfs_path *path)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct inode *inode = NULL;
 	u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
 
@@ -857,7 +858,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
 	 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
 	 * we will never try to read their inode item while the fs is mounted.
 	 */
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	inode = lookup_free_space_inode(block_group, path);
 	if (IS_ERR(inode)) {
 		btrfs_free_path(path);
 		return 0;
@@ -1385,7 +1386,7 @@ int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
 	}
 	spin_unlock(&block_group->lock);
 
-	inode = lookup_free_space_inode(fs_info, block_group, path);
+	inode = lookup_free_space_inode(block_group, path);
 	if (IS_ERR(inode))
 		return 0;
 

fs/btrfs/free-space-cache.h

@@ -38,9 +38,9 @@ struct btrfs_free_space_op {
 
 struct btrfs_io_ctl;
 
-struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
-				      struct btrfs_block_group_cache
-				      *block_group, struct btrfs_path *path);
+struct inode *lookup_free_space_inode(
+		struct btrfs_block_group_cache *block_group,
+		struct btrfs_path *path);
 int create_free_space_inode(struct btrfs_trans_handle *trans,
 			    struct btrfs_block_group_cache *block_group,
 			    struct btrfs_path *path);

fs/btrfs/relocation.c

@@ -4299,7 +4299,7 @@ int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
 		goto out;
 	}
 
-	inode = lookup_free_space_inode(fs_info, rc->block_group, path);
+	inode = lookup_free_space_inode(rc->block_group, path);
 	btrfs_free_path(path);
 
 	if (!IS_ERR(inode))