Commit a1ee7362 authored by David Sterba's avatar David Sterba
Browse files

btrfs: do an allocation earlier during snapshot creation 



We can allocate pending_snapshot earlier and do not have to do cleanup
in case of failure.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4fb72bf2

fs/btrfs/ioctl.c

+9 −11
Original line number Diff line number Diff line
@@ -655,22 +655,20 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 
	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))

		return -EINVAL;



	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);

	if (!pending_snapshot)

		return -ENOMEM;



	atomic_inc(&root->will_be_snapshoted);

	smp_mb__after_atomic();

	btrfs_wait_for_no_snapshoting_writes(root);



	ret = btrfs_start_delalloc_inodes(root, 0);

	if (ret)

		goto out;

		goto dec_and_free;



	btrfs_wait_ordered_extents(root, -1);



	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);

	if (!pending_snapshot) {

		ret = -ENOMEM;

		goto out;

	}



	btrfs_init_block_rsv(&pending_snapshot->block_rsv,

			     BTRFS_BLOCK_RSV_TEMP);

	/*
@@ -686,7 +684,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 
					&pending_snapshot->qgroup_reserved,

					false);

	if (ret)

		goto free;

		goto dec_and_free;



	pending_snapshot->dentry = dentry;

	pending_snapshot->root = root;
@@ -737,11 +735,11 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 
	btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,

					 &pending_snapshot->block_rsv,

					 pending_snapshot->qgroup_reserved);

free:

	kfree(pending_snapshot);

out:

dec_and_free:

	if (atomic_dec_and_test(&root->will_be_snapshoted))

		wake_up_atomic_t(&root->will_be_snapshoted);

	kfree(pending_snapshot);



	return ret;

}