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Commit 3fd0a558 authored by Yan, Zheng's avatar Yan, Zheng Committed by Chris Mason
Browse files

Btrfs: Metadata ENOSPC handling for balance 



This patch adds metadata ENOSPC handling for the balance code.
It is consisted by following major changes:

1. Avoid COW tree leave in the phrase of merging tree.

2. Handle interaction with snapshot creation.

3. make the backref cache can live across transactions.

Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent efa56464

fs/btrfs/ctree.c

+3 −0
Original line number Diff line number Diff line
@@ -447,6 +447,9 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, 


	update_ref_for_cow(trans, root, buf, cow, &last_ref);



	if (root->ref_cows)

		btrfs_reloc_cow_block(trans, root, buf, cow);



	if (buf == root->node) {

		WARN_ON(parent && parent != buf);

		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||

fs/btrfs/ctree.h

+10 −1
Original line number Diff line number Diff line
@@ -2205,7 +2205,8 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, 
int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);

int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);

int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);

int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref);

int btrfs_drop_snapshot(struct btrfs_root *root,

			struct btrfs_block_rsv *block_rsv, int update_ref);

int btrfs_drop_subtree(struct btrfs_trans_handle *trans,

			struct btrfs_root *root,

			struct extent_buffer *node,
@@ -2479,4 +2480,12 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, 
			    struct btrfs_root *root);

int btrfs_recover_relocation(struct btrfs_root *root);

int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len);

void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,

			   struct btrfs_root *root, struct extent_buffer *buf,

			   struct extent_buffer *cow);

void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,

			      struct btrfs_pending_snapshot *pending,

			      u64 *bytes_to_reserve);

void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,

			      struct btrfs_pending_snapshot *pending);

#endif

fs/btrfs/extent-tree.c

+9 −14
Original line number Diff line number Diff line
@@ -5875,7 +5875,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans, 
 * also make sure backrefs for the shared block and all lower level

 * blocks are properly updated.

 */

int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)

int btrfs_drop_snapshot(struct btrfs_root *root,

			struct btrfs_block_rsv *block_rsv, int update_ref)

{

	struct btrfs_path *path;

	struct btrfs_trans_handle *trans;
@@ -5894,6 +5895,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref) 
	BUG_ON(!wc);



	trans = btrfs_start_transaction(tree_root, 0);

	if (block_rsv)

		trans->block_rsv = block_rsv;



	if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {

		level = btrfs_header_level(root->node);
@@ -5981,24 +5984,16 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref) 
		}



		BUG_ON(wc->level == 0);

		if (trans->transaction->in_commit ||

		    trans->transaction->delayed_refs.flushing) {

		if (btrfs_should_end_transaction(trans, tree_root)) {

			ret = btrfs_update_root(trans, tree_root,

						&root->root_key,

						root_item);

			BUG_ON(ret);



			btrfs_end_transaction(trans, tree_root);

			btrfs_end_transaction_throttle(trans, tree_root);

			trans = btrfs_start_transaction(tree_root, 0);

			if (IS_ERR(trans))

				return PTR_ERR(trans);

		} else {

			unsigned long update;

			update = trans->delayed_ref_updates;

			trans->delayed_ref_updates = 0;

			if (update)

				btrfs_run_delayed_refs(trans, tree_root,

						       update);

			if (block_rsv)

				trans->block_rsv = block_rsv;

		}

	}

	btrfs_release_path(root, path);
@@ -6026,7 +6021,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref) 
		kfree(root);

	}

out:

	btrfs_end_transaction(trans, tree_root);

	btrfs_end_transaction_throttle(trans, tree_root);

	kfree(wc);

	btrfs_free_path(path);

	return err;

fs/btrfs/relocation.c

+1144 −737

File changed.

Preview size limit exceeded, changes collapsed.

fs/btrfs/transaction.c

+4 −2
Original line number Diff line number Diff line
@@ -853,6 +853,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
		goto fail;

	}



	btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);

	btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);



	if (to_reserve > 0) {
@@ -924,6 +925,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);

	BUG_ON(IS_ERR(pending->snap));



	btrfs_reloc_post_snapshot(trans, pending);

	btrfs_orphan_post_snapshot(trans, pending);

fail:

	kfree(new_root_item);
@@ -1213,9 +1215,9 @@ int btrfs_clean_old_snapshots(struct btrfs_root *root) 


		if (btrfs_header_backref_rev(root->node) <

		    BTRFS_MIXED_BACKREF_REV)

			btrfs_drop_snapshot(root, 0);

			btrfs_drop_snapshot(root, NULL, 0);

		else

			btrfs_drop_snapshot(root, 1);

			btrfs_drop_snapshot(root, NULL, 1);

	}

	return 0;

}