[PATCH v3 10/11] Btrfs: get rid of unused orphan infrastructure

[Omar Sandoval <osandov@osandov.com>]

From: Omar Sandoval <osandov@fb.com>

Now that we don't keep long-standing reservations for orphan items,
root->orphan_block_rsv isn't used. We can git rid of it, along with
root->orphan_lock, which was used to protect it, root->orphan_inodes,
which was used as a refcount for it, and btrfs_orphan_commit_root(),
which was the last user of all of these.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/ctree.h       |  8 --------
 fs/btrfs/disk-io.c     |  9 ---------
 fs/btrfs/extent-tree.c | 38 -------------------------------------
 fs/btrfs/inode.c       | 43 +-----------------------------------------
 fs/btrfs/transaction.c |  1 -
 5 files changed, 1 insertion(+), 98 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2771cc56a622..51408de11af2 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1219,9 +1219,6 @@ struct btrfs_root {
 	spinlock_t log_extents_lock[2];
 	struct list_head logged_list[2];
 
-	spinlock_t orphan_lock;
-	atomic_t orphan_inodes;
-	struct btrfs_block_rsv *orphan_block_rsv;
 	int orphan_cleanup_state;
 
 	spinlock_t inode_lock;
@@ -2764,9 +2761,6 @@ void btrfs_delalloc_release_space(struct inode *inode,
 void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
 					    u64 len);
 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
-int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
-				  struct btrfs_inode *inode);
-void btrfs_orphan_release_metadata(struct btrfs_inode *inode);
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 				     struct btrfs_block_rsv *rsv,
 				     int nitems,
@@ -3238,8 +3232,6 @@ int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
 		struct btrfs_inode *inode);
 int btrfs_orphan_cleanup(struct btrfs_root *root);
-void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root);
 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size);
 void btrfs_invalidate_inodes(struct btrfs_root *root);
 void btrfs_add_delayed_iput(struct inode *inode);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 60caa68c3618..4a40bfdddabc 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1185,7 +1185,6 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 	root->inode_tree = RB_ROOT;
 	INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
 	root->block_rsv = NULL;
-	root->orphan_block_rsv = NULL;
 
 	INIT_LIST_HEAD(&root->dirty_list);
 	INIT_LIST_HEAD(&root->root_list);
@@ -1195,7 +1194,6 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 	INIT_LIST_HEAD(&root->ordered_root);
 	INIT_LIST_HEAD(&root->logged_list[0]);
 	INIT_LIST_HEAD(&root->logged_list[1]);
-	spin_lock_init(&root->orphan_lock);
 	spin_lock_init(&root->inode_lock);
 	spin_lock_init(&root->delalloc_lock);
 	spin_lock_init(&root->ordered_extent_lock);
@@ -1216,7 +1214,6 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 	atomic_set(&root->log_commit[1], 0);
 	atomic_set(&root->log_writers, 0);
 	atomic_set(&root->log_batch, 0);
-	atomic_set(&root->orphan_inodes, 0);
 	refcount_set(&root->refs, 1);
 	atomic_set(&root->will_be_snapshotted, 0);
 	root->log_transid = 0;
@@ -3674,8 +3671,6 @@ static void free_fs_root(struct btrfs_root *root)
 {
 	iput(root->ino_cache_inode);
 	WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
-	btrfs_free_block_rsv(root->fs_info, root->orphan_block_rsv);
-	root->orphan_block_rsv = NULL;
 	if (root->anon_dev)
 		free_anon_bdev(root->anon_dev);
 	if (root->subv_writers)
@@ -3766,7 +3761,6 @@ int btrfs_commit_super(struct btrfs_fs_info *fs_info)
 
 void close_ctree(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_root *root = fs_info->tree_root;
 	int ret;
 
 	set_bit(BTRFS_FS_CLOSING_START, &fs_info->flags);
@@ -3861,9 +3855,6 @@ void close_ctree(struct btrfs_fs_info *fs_info)
 	btrfs_free_stripe_hash_table(fs_info);
 	btrfs_free_ref_cache(fs_info);
 
-	__btrfs_free_block_rsv(root->orphan_block_rsv);
-	root->orphan_block_rsv = NULL;
-
 	while (!list_empty(&fs_info->pinned_chunks)) {
 		struct extent_map *em;
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 51b5e2da708c..3f2e026bc206 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5949,44 +5949,6 @@ void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
 	trans->chunk_bytes_reserved = 0;
 }
 
-/* Can only return 0 or -ENOSPC */
-int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
-				  struct btrfs_inode *inode)
-{
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
-	struct btrfs_root *root = inode->root;
-	/*
-	 * We always use trans->block_rsv here as we will have reserved space
-	 * for our orphan when starting the transaction, using get_block_rsv()
-	 * here will sometimes make us choose the wrong block rsv as we could be
-	 * doing a reloc inode for a non refcounted root.
-	 */
-	struct btrfs_block_rsv *src_rsv = trans->block_rsv;
-	struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
-
-	/*
-	 * We need to hold space in order to delete our orphan item once we've
-	 * added it, so this takes the reservation so we can release it later
-	 * when we are truly done with the orphan item.
-	 */
-	u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
-
-	trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
-			num_bytes, 1);
-	return btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
-}
-
-void btrfs_orphan_release_metadata(struct btrfs_inode *inode)
-{
-	struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
-	struct btrfs_root *root = inode->root;
-	u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
-
-	trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
-			num_bytes, 0);
-	btrfs_block_rsv_release(fs_info, root->orphan_block_rsv, num_bytes);
-}
-
 /*
  * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
  * root: the root of the parent directory
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b64c4189e2c0..1edb4148ec74 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3292,42 +3292,6 @@ void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
 	spin_unlock(&fs_info->delayed_iput_lock);
 }
 
-/*
- * This is called in transaction commit time. If there are no orphan
- * files in the subvolume, it removes orphan item and frees block_rsv
- * structure.
- */
-void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_rsv *block_rsv;
-
-	if (atomic_read(&root->orphan_inodes) ||
-	    root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
-		return;
-
-	spin_lock(&root->orphan_lock);
-	if (atomic_read(&root->orphan_inodes)) {
-		spin_unlock(&root->orphan_lock);
-		return;
-	}
-
-	if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
-		spin_unlock(&root->orphan_lock);
-		return;
-	}
-
-	block_rsv = root->orphan_block_rsv;
-	root->orphan_block_rsv = NULL;
-	spin_unlock(&root->orphan_lock);
-
-	if (block_rsv) {
-		WARN_ON(block_rsv->size > 0);
-		btrfs_free_block_rsv(fs_info, block_rsv);
-	}
-}
-
 /*
  * This creates an orphan entry for the given inode in case something goes wrong
  * in the middle of an unlink.
@@ -3521,12 +3485,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 
 	root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
 
-	if (root->orphan_block_rsv)
-		btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
-					(u64)-1);
-
-	if (root->orphan_block_rsv ||
-	    test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
+	if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
 		trans = btrfs_join_transaction(root);
 		if (!IS_ERR(trans))
 			btrfs_end_transaction(trans);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index c944b4769e3c..44af1edf15d1 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1250,7 +1250,6 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans)
 
 			btrfs_free_log(trans, root);
 			btrfs_update_reloc_root(trans, root);
-			btrfs_orphan_commit_root(trans, root);
 
 			btrfs_save_ino_cache(root, trans);
 
-- 
2.17.0