Commit dba68306 authored by Josef Bacik's avatar Josef Bacik
Browse files

Btrfs: kill the orphan space calculation for snapshots 



This patch kills off the calculation for the amount of space needed for the
orphan operations during a snapshot.  The thing is we only do snapshots on
commit, so any space that is in the block_rsv->freed[] isn't going to be in the
new snapshot anyway, so there isn't any reason to require that space to be
reserved for the snapshot to occur.  Thanks,

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
parent 7709cde3

fs/btrfs/ctree.h

+0 −5
Original line number Diff line number Diff line
@@ -2577,11 +2577,6 @@ int btrfs_update_inode(struct btrfs_trans_handle *trans, 
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);

int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);

int btrfs_orphan_cleanup(struct btrfs_root *root);

void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending,

				u64 *bytes_to_reserve);

void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending);

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);

fs/btrfs/inode.c

+0 −83
Original line number Diff line number Diff line
@@ -2079,89 +2079,6 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root) 
	up_read(&root->fs_info->cleanup_work_sem);

}



/*

 * calculate extra metadata reservation when snapshotting a subvolume

 * contains orphan files.

 */

void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending,

				u64 *bytes_to_reserve)

{

	struct btrfs_root *root;

	struct btrfs_block_rsv *block_rsv;

	u64 num_bytes;

	int index;



	root = pending->root;

	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))

		return;



	block_rsv = root->orphan_block_rsv;



	/* orphan block reservation for the snapshot */

	num_bytes = block_rsv->size;



	/*

	 * after the snapshot is created, COWing tree blocks may use more

	 * space than it frees. So we should make sure there is enough

	 * reserved space.

	 */

	index = trans->transid & 0x1;

	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {

		num_bytes += block_rsv->size -

			     (block_rsv->reserved + block_rsv->freed[index]);

	}



	*bytes_to_reserve += num_bytes;

}



void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending)

{

	struct btrfs_root *root = pending->root;

	struct btrfs_root *snap = pending->snap;

	struct btrfs_block_rsv *block_rsv;

	u64 num_bytes;

	int index;

	int ret;



	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))

		return;



	/* refill source subvolume's orphan block reservation */

	block_rsv = root->orphan_block_rsv;

	index = trans->transid & 0x1;

	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {

		num_bytes = block_rsv->size -

			    (block_rsv->reserved + block_rsv->freed[index]);

		ret = btrfs_block_rsv_migrate(&pending->block_rsv,

					      root->orphan_block_rsv,

					      num_bytes);

		BUG_ON(ret);

	}



	/* setup orphan block reservation for the snapshot */

	block_rsv = btrfs_alloc_block_rsv(snap);

	BUG_ON(!block_rsv);



	btrfs_add_durable_block_rsv(root->fs_info, block_rsv);

	snap->orphan_block_rsv = block_rsv;



	num_bytes = root->orphan_block_rsv->size;

	ret = btrfs_block_rsv_migrate(&pending->block_rsv,

				      block_rsv, num_bytes);

	BUG_ON(ret);



#if 0

	/* insert orphan item for the snapshot */

	WARN_ON(!root->orphan_item_inserted);

	ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,

				       snap->root_key.objectid);

	BUG_ON(ret);

	snap->orphan_item_inserted = 1;

#endif

}



enum btrfs_orphan_cleanup_state {

	ORPHAN_CLEANUP_STARTED	= 1,

	ORPHAN_CLEANUP_DONE	= 2,

fs/btrfs/transaction.c

+0 −2
Original line number Diff line number Diff line
@@ -911,7 +911,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	}



	btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);

	btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);



	if (to_reserve > 0) {

		ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv,
@@ -1002,7 +1001,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	BUG_ON(IS_ERR(pending->snap));



	btrfs_reloc_post_snapshot(trans, pending);

	btrfs_orphan_post_snapshot(trans, pending);

fail:

	kfree(new_root_item);

	trans->block_rsv = rsv;

CRA Git | Maintained and supported by SUSTech CRA and CCSE