Commit 13a8a7c8 authored by Yan, Zheng's avatar Yan, Zheng Committed by Chris Mason
Browse files

Btrfs: do not reuse objectid of deleted snapshot/subvol 



The new back reference format does not allow reusing objectid of
deleted snapshot/subvol. So we use ++highest_objectid to allocate
objectid for new snapshot/subvol.

Now we use ++highest_objectid to allocate objectid for both new inode
and new snapshot/subvolume, so this patch removes 'find hole' code in
btrfs_find_free_objectid.

Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 1c4850e2

fs/btrfs/ctree.h

+2 −2
Original line number Diff line number Diff line
@@ -1007,8 +1007,8 @@ struct btrfs_root { 
	u32 stripesize;



	u32 type;

	u64 highest_inode;

	u64 last_inode_alloc;



	u64 highest_objectid;

	int ref_cows;

	int track_dirty;

	u64 defrag_trans_start;

fs/btrfs/disk-io.c

+14 −25
Original line number Diff line number Diff line
@@ -895,8 +895,7 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, 
	root->fs_info = fs_info;

	root->objectid = objectid;

	root->last_trans = 0;

	root->highest_inode = 0;

	root->last_inode_alloc = 0;

	root->highest_objectid = 0;

	root->name = NULL;

	root->in_sysfs = 0;

	root->inode_tree.rb_node = NULL;
@@ -1095,7 +1094,6 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, 
	struct btrfs_fs_info *fs_info = tree_root->fs_info;

	struct btrfs_path *path;

	struct extent_buffer *l;

	u64 highest_inode;

	u64 generation;

	u32 blocksize;

	int ret = 0;
@@ -1110,7 +1108,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, 
			kfree(root);

			return ERR_PTR(ret);

		}

		goto insert;

		goto out;

	}



	__setup_root(tree_root->nodesize, tree_root->leafsize,
@@ -1120,39 +1118,30 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, 
	path = btrfs_alloc_path();

	BUG_ON(!path);

	ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);

	if (ret != 0) {

		if (ret > 0)

			ret = -ENOENT;

		goto out;

	}

	if (ret == 0) {

		l = path->nodes[0];

		read_extent_buffer(l, &root->root_item,

				btrfs_item_ptr_offset(l, path->slots[0]),

				sizeof(root->root_item));

		memcpy(&root->root_key, location, sizeof(*location));

	ret = 0;

out:

	btrfs_release_path(root, path);

	}

	btrfs_free_path(path);

	if (ret) {

		kfree(root);

		if (ret > 0)

			ret = -ENOENT;

		return ERR_PTR(ret);

	}



	generation = btrfs_root_generation(&root->root_item);

	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));

	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),

				     blocksize, generation);

	root->commit_root = btrfs_root_node(root);

	BUG_ON(!root->node);

insert:

	if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {

out:

	if (location->objectid != BTRFS_TREE_LOG_OBJECTID)

		root->ref_cows = 1;

		ret = btrfs_find_highest_inode(root, &highest_inode);

		if (ret == 0) {

			root->highest_inode = highest_inode;

			root->last_inode_alloc = highest_inode;

		}

	}



	return root;

}

fs/btrfs/inode-item.c

+0 −2
Original line number Diff line number Diff line
@@ -177,8 +177,6 @@ int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, 


	ret = btrfs_insert_empty_item(trans, root, path, &key,

				      sizeof(struct btrfs_inode_item));

	if (ret == 0 && objectid > root->highest_inode)

		root->highest_inode = objectid;

	return ret;

}

fs/btrfs/inode-map.c

+15 −78
Original line number Diff line number Diff line
@@ -43,9 +43,10 @@ int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid) 
		slot = path->slots[0] - 1;

		l = path->nodes[0];

		btrfs_item_key_to_cpu(l, &found_key, slot);

		*objectid = found_key.objectid;

		*objectid = max_t(u64, found_key.objectid,

				  BTRFS_FIRST_FREE_OBJECTID - 1);

	} else {

		*objectid = BTRFS_FIRST_FREE_OBJECTID;

		*objectid = BTRFS_FIRST_FREE_OBJECTID - 1;

	}

	ret = 0;

error:
@@ -53,91 +54,27 @@ error: 
	return ret;

}



/*

 * walks the btree of allocated inodes and find a hole.

 */

int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,

			     struct btrfs_root *root,

			     u64 dirid, u64 *objectid)

{

	struct btrfs_path *path;

	struct btrfs_key key;

	int ret;

	int slot = 0;

	u64 last_ino = 0;

	int start_found;

	struct extent_buffer *l;

	struct btrfs_key search_key;

	u64 search_start = dirid;



	mutex_lock(&root->objectid_mutex);

	if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&

	    root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {

		*objectid = ++root->last_inode_alloc;

		mutex_unlock(&root->objectid_mutex);

		return 0;

	}

	path = btrfs_alloc_path();

	BUG_ON(!path);

	search_start = max(search_start, (u64)BTRFS_FIRST_FREE_OBJECTID);

	search_key.objectid = search_start;

	search_key.type = 0;

	search_key.offset = 0;



	start_found = 0;

	ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);

	if (ret < 0)

		goto error;



	while (1) {

		l = path->nodes[0];

		slot = path->slots[0];

		if (slot >= btrfs_header_nritems(l)) {

			ret = btrfs_next_leaf(root, path);

			if (ret == 0)

				continue;

			if (ret < 0)

				goto error;

			if (!start_found) {

				*objectid = search_start;

				start_found = 1;

				goto found;

			}

			*objectid = last_ino > search_start ?

				last_ino : search_start;

			goto found;

		}

		btrfs_item_key_to_cpu(l, &key, slot);

		if (key.objectid >= search_start) {

			if (start_found) {

				if (last_ino < search_start)

					last_ino = search_start;

				if (key.objectid > last_ino) {

					*objectid = last_ino;

					goto found;

				}

			} else if (key.objectid > search_start) {

				*objectid = search_start;

				goto found;

			}

	if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) {

		ret = btrfs_find_highest_inode(root, &root->highest_objectid);

		if (ret)

			goto out;

	}

		if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)

			break;



		start_found = 1;

		last_ino = key.objectid + 1;

		path->slots[0]++;

	if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {

		ret = -ENOSPC;

		goto out;

	}

	BUG_ON(1);

found:

	btrfs_release_path(root, path);

	btrfs_free_path(path);

	BUG_ON(*objectid < search_start);

	mutex_unlock(&root->objectid_mutex);

	return 0;

error:

	btrfs_release_path(root, path);

	btrfs_free_path(path);



	*objectid = ++root->highest_objectid;

	ret = 0;

out:

	mutex_unlock(&root->objectid_mutex);

	return ret;

}

fs/btrfs/inode.c

+0 −3
Original line number Diff line number Diff line
@@ -3624,9 +3624,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
	if (ret != 0)

		goto fail;



	if (objectid > root->highest_inode)

		root->highest_inode = objectid;



	inode->i_uid = current_fsuid();



	if (dir && (dir->i_mode & S_ISGID)) {

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