Btrfs: create UUID tree if required

This tree is not created by mkfs.btrfs. Therefore when a filesystem
is mounted writable and the UUID tree does not exist, this tree is
created if required. The tree is also added to the fs_info structure
and initialized, but this commit does not yet read or write UUID tree
elements.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Stefan Behrens 2013-08-15 17:11:19 +02:00 committed by Chris Mason
parent 8f8ae8e213
commit f7a81ea4cc
5 changed files with 65 additions and 0 deletions

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@ -1306,6 +1306,7 @@ struct btrfs_fs_info {
struct btrfs_root *fs_root;
struct btrfs_root *csum_root;
struct btrfs_root *quota_root;
struct btrfs_root *uuid_root;
/* the log root tree is a directory of all the other log roots */
struct btrfs_root *log_root_tree;

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@ -1586,6 +1586,9 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
return fs_info->quota_root ? fs_info->quota_root :
ERR_PTR(-ENOENT);
if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
return fs_info->uuid_root ? fs_info->uuid_root :
ERR_PTR(-ENOENT);
again:
root = btrfs_lookup_fs_root(fs_info, location->objectid);
if (root)
@ -2044,6 +2047,12 @@ static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
info->quota_root->node = NULL;
info->quota_root->commit_root = NULL;
}
if (info->uuid_root) {
free_extent_buffer(info->uuid_root->node);
free_extent_buffer(info->uuid_root->commit_root);
info->uuid_root->node = NULL;
info->uuid_root->commit_root = NULL;
}
if (chunk_root) {
free_extent_buffer(info->chunk_root->node);
free_extent_buffer(info->chunk_root->commit_root);
@ -2104,11 +2113,13 @@ int open_ctree(struct super_block *sb,
struct btrfs_root *chunk_root;
struct btrfs_root *dev_root;
struct btrfs_root *quota_root;
struct btrfs_root *uuid_root;
struct btrfs_root *log_tree_root;
int ret;
int err = -EINVAL;
int num_backups_tried = 0;
int backup_index = 0;
bool create_uuid_tree = false;
tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
@ -2704,6 +2715,18 @@ retry_root_backup:
fs_info->quota_root = quota_root;
}
location.objectid = BTRFS_UUID_TREE_OBJECTID;
uuid_root = btrfs_read_tree_root(tree_root, &location);
if (IS_ERR(uuid_root)) {
ret = PTR_ERR(uuid_root);
if (ret != -ENOENT)
goto recovery_tree_root;
create_uuid_tree = true;
} else {
uuid_root->track_dirty = 1;
fs_info->uuid_root = uuid_root;
}
fs_info->generation = generation;
fs_info->last_trans_committed = generation;
@ -2890,6 +2913,17 @@ retry_root_backup:
btrfs_qgroup_rescan_resume(fs_info);
if (create_uuid_tree) {
pr_info("btrfs: creating UUID tree\n");
ret = btrfs_create_uuid_tree(fs_info);
if (ret) {
pr_warn("btrfs: failed to create the UUID tree %d\n",
ret);
close_ctree(tree_root);
return ret;
}
}
return 0;
fail_qgroup:

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@ -4361,6 +4361,9 @@ static struct btrfs_block_rsv *get_block_rsv(
if (root == root->fs_info->csum_root && trans->adding_csums)
block_rsv = trans->block_rsv;
if (root == root->fs_info->uuid_root)
block_rsv = trans->block_rsv;
if (!block_rsv)
block_rsv = root->block_rsv;

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@ -3429,6 +3429,32 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
return 0;
}
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *uuid_root;
/*
* 1 - root node
* 1 - root item
*/
trans = btrfs_start_transaction(tree_root, 2);
if (IS_ERR(trans))
return PTR_ERR(trans);
uuid_root = btrfs_create_tree(trans, fs_info,
BTRFS_UUID_TREE_OBJECTID);
if (IS_ERR(uuid_root)) {
btrfs_abort_transaction(trans, tree_root,
PTR_ERR(uuid_root));
return PTR_ERR(uuid_root);
}
fs_info->uuid_root = uuid_root;
return btrfs_commit_transaction(trans, tree_root);
}
/*
* shrinking a device means finding all of the device extents past
* the new size, and then following the back refs to the chunks.

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@ -322,6 +322,7 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
int find_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,