Commit d5c12070 authored by Miao Xie's avatar Miao Xie Committed by Josef Bacik
Browse files

Btrfs: fix wrong reserved space in qgroup during snap/subv creation 



There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
  the free space reservation. we need reserve free space for
  7 items, but in qgroup reservation, we need reserve space only
  for 3 items.

So we implement new metadata reservation functions for the
snapshot/subvolume creation.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent e9662f70

fs/btrfs/ctree.h

+7 −2
Original line number Diff line number Diff line
@@ -3106,8 +3106,13 @@ void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans, 
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,

				  struct inode *inode);

void btrfs_orphan_release_metadata(struct inode *inode);

int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending);

int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,

				     struct btrfs_block_rsv *rsv,

				     int nitems,

				     u64 *qgroup_reserved);

void btrfs_subvolume_release_metadata(struct btrfs_root *root,

				      struct btrfs_block_rsv *rsv,

				      u64 qgroup_reserved);

int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes);

void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes);

int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes);

fs/btrfs/extent-tree.c

+53 −12
Original line number Diff line number Diff line
@@ -4560,19 +4560,60 @@ void btrfs_orphan_release_metadata(struct inode *inode) 
	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);

}



int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,

				struct btrfs_pending_snapshot *pending)

{

	struct btrfs_root *root = pending->root;

	struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);

	struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;

/*

	 * two for root back/forward refs, two for directory entries,

	 * one for root of the snapshot and one for parent inode.

	 */

	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 6);

	dst_rsv->space_info = src_rsv->space_info;

	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);

 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation

 * root: the root of the parent directory

 * rsv: block reservation

 * items: the number of items that we need do reservation

 * qgroup_reserved: used to return the reserved size in qgroup

 *

 * This function is used to reserve the space for snapshot/subvolume

 * creation and deletion. Those operations are different with the

 * common file/directory operations, they change two fs/file trees

 * and root tree, the number of items that the qgroup reserves is

 * different with the free space reservation. So we can not use

 * the space reseravtion mechanism in start_transaction().

 */

int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,

				     struct btrfs_block_rsv *rsv,

				     int items,

				     u64 *qgroup_reserved)

{

	u64 num_bytes;

	int ret;



	if (root->fs_info->quota_enabled) {

		/* One for parent inode, two for dir entries */

		num_bytes = 3 * root->leafsize;

		ret = btrfs_qgroup_reserve(root, num_bytes);

		if (ret)

			return ret;

	} else {

		num_bytes = 0;

	}



	*qgroup_reserved = num_bytes;



	num_bytes = btrfs_calc_trans_metadata_size(root, items);

	rsv->space_info = __find_space_info(root->fs_info,

					    BTRFS_BLOCK_GROUP_METADATA);

	ret = btrfs_block_rsv_add(root, rsv, num_bytes,

				  BTRFS_RESERVE_FLUSH_ALL);

	if (ret) {

		if (*qgroup_reserved)

			btrfs_qgroup_free(root, *qgroup_reserved);

	}



	return ret;

}



void btrfs_subvolume_release_metadata(struct btrfs_root *root,

				      struct btrfs_block_rsv *rsv,

				      u64 qgroup_reserved)

{

	btrfs_block_rsv_release(root, rsv, (u64)-1);

	if (qgroup_reserved)

		btrfs_qgroup_free(root, qgroup_reserved);

}



/**

fs/btrfs/ioctl.c

+43 −19
Original line number Diff line number Diff line
@@ -363,7 +363,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) 
	return 0;

}



static noinline int create_subvol(struct btrfs_root *root,

static noinline int create_subvol(struct inode *dir,

				  struct dentry *dentry,

				  char *name, int namelen,

				  u64 *async_transid,
@@ -374,32 +374,39 @@ static noinline int create_subvol(struct btrfs_root *root, 
	struct btrfs_root_item root_item;

	struct btrfs_inode_item *inode_item;

	struct extent_buffer *leaf;

	struct btrfs_root *root = BTRFS_I(dir)->root;

	struct btrfs_root *new_root;

	struct dentry *parent = dentry->d_parent;

	struct inode *dir;

	struct btrfs_block_rsv block_rsv;

	struct timespec cur_time = CURRENT_TIME;

	int ret;

	int err;

	u64 objectid;

	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;

	u64 index = 0;

	u64 qgroup_reserved;

	uuid_le new_uuid;



	ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);

	if (ret)

		return ret;



	dir = parent->d_inode;



	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);

	/*

	 * 1 - inode item

	 * 2 - refs

	 * 1 - root item

	 * 2 - dir items

	 * The same as the snapshot creation, please see the comment

	 * of create_snapshot().

	 */

	trans = btrfs_start_transaction(root, 6);

	if (IS_ERR(trans))

		return PTR_ERR(trans);

	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,

					       7, &qgroup_reserved);

	if (ret)

		return ret;



	trans = btrfs_start_transaction(root, 0);

	if (IS_ERR(trans)) {

		ret = PTR_ERR(trans);

		goto out;

	}

	trans->block_rsv = &block_rsv;

	trans->bytes_reserved = block_rsv.size;



	ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);

	if (ret)
@@ -515,6 +522,8 @@ static noinline int create_subvol(struct btrfs_root *root, 
	BUG_ON(ret);



fail:

	trans->block_rsv = NULL;

	trans->bytes_reserved = 0;

	if (async_transid) {

		*async_transid = trans->transid;

		err = btrfs_commit_transaction_async(trans, root, 1);
@@ -526,7 +535,8 @@ fail: 


	if (!ret)

		d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));



out:

	btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);

	return ret;

}
@@ -549,21 +559,31 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 


	btrfs_init_block_rsv(&pending_snapshot->block_rsv,

			     BTRFS_BLOCK_RSV_TEMP);

	/*

	 * 1 - parent dir inode

	 * 2 - dir entries

	 * 1 - root item

	 * 2 - root ref/backref

	 * 1 - root of snapshot

	 */

	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,

					&pending_snapshot->block_rsv, 7,

					&pending_snapshot->qgroup_reserved);

	if (ret)

		goto out;



	pending_snapshot->dentry = dentry;

	pending_snapshot->root = root;

	pending_snapshot->readonly = readonly;

	pending_snapshot->dir = dir;

	pending_snapshot->inherit = inherit;



	trans = btrfs_start_transaction(root->fs_info->extent_root, 6);

	trans = btrfs_start_transaction(root, 0);

	if (IS_ERR(trans)) {

		ret = PTR_ERR(trans);

		goto fail;

	}



	ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);

	BUG_ON(ret);



	spin_lock(&root->fs_info->trans_lock);

	list_add(&pending_snapshot->list,

		 &trans->transaction->pending_snapshots);
@@ -600,6 +620,10 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 
	d_instantiate(dentry, inode);

	ret = 0;

fail:

	btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,

					 &pending_snapshot->block_rsv,

					 pending_snapshot->qgroup_reserved);

out:

	kfree(pending_snapshot);

	return ret;

}
@@ -733,8 +757,8 @@ static noinline int btrfs_mksubvol(struct path *parent, 
		error = create_snapshot(snap_src, dir, dentry, name, namelen,

					async_transid, readonly, inherit);

	} else {

		error = create_subvol(BTRFS_I(dir)->root, dentry,

				      name, namelen, async_transid, inherit);

		error = create_subvol(dir, dentry, name, namelen,

				      async_transid, inherit);

	}

	if (!error)

		fsnotify_mkdir(dir, dentry);

fs/btrfs/transaction.c

+1 −3
Original line number Diff line number Diff line
@@ -1082,7 +1082,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	path = btrfs_alloc_path();

	if (!path) {

		ret = pending->error = -ENOMEM;

		goto path_alloc_fail;

		return ret;

	}



	new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
@@ -1279,8 +1279,6 @@ no_free_objectid: 
	kfree(new_root_item);

root_item_alloc_fail:

	btrfs_free_path(path);

path_alloc_fail:

	btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);

	return ret;

}

fs/btrfs/transaction.h

+1 −0
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ struct btrfs_pending_snapshot { 
	struct btrfs_qgroup_inherit *inherit;

	/* block reservation for the operation */

	struct btrfs_block_rsv block_rsv;

	u64 qgroup_reserved;

	/* extra metadata reseration for relocation */

	int error;

	bool readonly;

CRA Git | Maintained and supported by SUSTech CRA and CCSE