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>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 429c54a..c03e61e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1306,6 +1306,7 @@
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;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f96a237..80bd637 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1586,6 +1586,9 @@
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 @@
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 @@
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 @@
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 @@
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:
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f1c1694..8cb1d41 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4361,6 +4361,9 @@
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;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 306547b..e084218 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3429,6 +3429,32 @@
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.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 08c44d9..7071b298 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -322,6 +322,7 @@
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,
