int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 transid = trans->transid;
int ret = 0;
struct btrfs_fs_info *fs_info = root->fs_info;
if (root->commit_root == root->node)
goto commit_tree;
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
btrfs_set_root_bytenr(&root->root_item, root->node->start);
btrfs_set_root_generation(&root->root_item, trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
BUG_ON(ret);
commit_tree:
ret = commit_tree_roots(trans, fs_info);
BUG_ON(ret);
ret = __commit_transaction(trans, root);
BUG_ON(ret);
write_ctree_super(trans, root);
btrfs_finish_extent_commit(trans, fs_info->extent_root,
&fs_info->pinned_extents);
btrfs_free_transaction(root, trans);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = transid;
return 0;
}
/*
* this is used to update the root pointer in the tree of tree roots.
*
* But, in the case of the extent allocation tree, updating the root
* pointer may allocate blocks which may change the root of the extent
* allocation tree.
*
* So, this loops and repeats and makes sure the cowonly root didn't
* change while the root pointer was being updated in the metadata.
*/
static int update_cowonly_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_root_bytenr;
struct btrfs_root *tree_root = root->fs_info->tree_root;
btrfs_write_dirty_block_groups(trans, root);
while (1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
break;
btrfs_set_root_node(&root->root_item, root->node);
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
BUG_ON(ret);
ret = btrfs_write_dirty_block_groups(trans, root);
BUG_ON(ret);
}
if (root != root->fs_info->extent_root)
switch_commit_root(root);
return 0;
}
static int update_cowonly_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_root_bytenr;
struct btrfs_root *tree_root = root->fs_info->tree_root;
btrfs_write_dirty_block_groups(trans, root);
while(1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
break;
btrfs_set_root_bytenr(&root->root_item,
root->node->start);
btrfs_set_root_generation(&root->root_item,
trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
BUG_ON(ret);
btrfs_write_dirty_block_groups(trans, root);
}
return 0;
}
/*
* Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
* all of them
*/
int btrfs_drop_dead_root(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
unsigned long nr;
int ret;
while (1) {
/*
* we don't want to jump in and create a bunch of
* delayed refs if the transaction is starting to close
*/
wait_transaction_pre_flush(tree_root->fs_info);
trans = btrfs_start_transaction(tree_root, 1);
/*
* we've joined a transaction, make sure it isn't
* closing right now
*/
if (trans->transaction->delayed_refs.flushing) {
btrfs_end_transaction(trans, tree_root);
continue;
}
ret = btrfs_drop_snapshot(trans, root);
if (ret != -EAGAIN)
break;
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
if (ret)
break;
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
}
BUG_ON(ret);
ret = btrfs_del_root(trans, tree_root, &root->root_key);
BUG_ON(ret);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
kfree(root);
btrfs_btree_balance_dirty(tree_root, nr);
return ret;
}
static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_root *gang[8];
struct btrfs_fs_info *fs_info = root->fs_info;
int i;
int ret;
int err = 0;
while (1) {
ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
(void **)gang, 0,
ARRAY_SIZE(gang),
BTRFS_ROOT_TRANS_TAG);
if (ret == 0)
break;
for (i = 0; i < ret; i++) {
root = gang[i];
radix_tree_tag_clear(&fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_TRANS_TAG);
btrfs_free_log(trans, root);
btrfs_update_reloc_root(trans, root);
btrfs_orphan_commit_root(trans, root);
if (root->commit_root != root->node) {
switch_commit_root(root);
btrfs_set_root_node(&root->root_item,
root->node);
}
err = btrfs_update_root(trans, fs_info->tree_root,
&root->root_key,
&root->root_item);
if (err)
break;
}
}
return err;
}
/*
* Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
* all of them
*/
static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
struct list_head *list)
{
struct btrfs_dirty_root *dirty;
struct btrfs_trans_handle *trans;
unsigned long nr;
u64 num_bytes;
u64 bytes_used;
u64 max_useless;
int ret = 0;
int err;
while (!list_empty(list)) {
struct btrfs_root *root;
dirty = list_entry(list->prev, struct btrfs_dirty_root, list);
list_del_init(&dirty->list);
num_bytes = btrfs_root_used(&dirty->root->root_item);
root = dirty->latest_root;
atomic_inc(&root->fs_info->throttles);
while (1) {
/*
* we don't want to jump in and create a bunch of
* delayed refs if the transaction is starting to close
*/
wait_transaction_pre_flush(tree_root->fs_info);
trans = btrfs_start_transaction(tree_root, 1);
/*
* we've joined a transaction, make sure it isn't
* closing right now
*/
if (trans->transaction->delayed_refs.flushing) {
btrfs_end_transaction(trans, tree_root);
continue;
}
mutex_lock(&root->fs_info->drop_mutex);
ret = btrfs_drop_snapshot(trans, dirty->root);
if (ret != -EAGAIN)
break;
mutex_unlock(&root->fs_info->drop_mutex);
err = btrfs_update_root(trans,
tree_root,
&dirty->root->root_key,
&dirty->root->root_item);
if (err)
ret = err;
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
}
BUG_ON(ret);
atomic_dec(&root->fs_info->throttles);
wake_up(&root->fs_info->transaction_throttle);
num_bytes -= btrfs_root_used(&dirty->root->root_item);
bytes_used = btrfs_root_used(&root->root_item);
if (num_bytes) {
mutex_lock(&root->fs_info->trans_mutex);
btrfs_record_root_in_trans(root);
mutex_unlock(&root->fs_info->trans_mutex);
btrfs_set_root_used(&root->root_item,
bytes_used - num_bytes);
}
ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
if (ret) {
BUG();
break;
}
mutex_unlock(&root->fs_info->drop_mutex);
spin_lock(&root->list_lock);
list_del_init(&dirty->root->dead_list);
if (!list_empty(&root->dead_list)) {
struct btrfs_root *oldest;
oldest = list_entry(root->dead_list.prev,
struct btrfs_root, dead_list);
max_useless = oldest->root_key.offset - 1;
} else {
max_useless = root->root_key.offset - 1;
}
spin_unlock(&root->list_lock);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
ret = btrfs_remove_leaf_refs(root, max_useless, 0);
BUG_ON(ret);
free_extent_buffer(dirty->root->node);
kfree(dirty->root);
kfree(dirty);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
}
/*
* at transaction commit time we need to schedule the old roots for
* deletion via btrfs_drop_snapshot. This runs through all the
* reference counted roots that were modified in the current
* transaction and puts them into the drop list
*/
static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
struct radix_tree_root *radix,
struct list_head *list)
{
struct btrfs_dirty_root *dirty;
struct btrfs_root *gang[8];
struct btrfs_root *root;
int i;
int ret;
int err = 0;
u32 refs;
while (1) {
ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
ARRAY_SIZE(gang),
BTRFS_ROOT_TRANS_TAG);
if (ret == 0)
break;
for (i = 0; i < ret; i++) {
root = gang[i];
radix_tree_tag_clear(radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_TRANS_TAG);
BUG_ON(!root->ref_tree);
dirty = root->dirty_root;
btrfs_free_log(trans, root);
btrfs_free_reloc_root(trans, root);
if (root->commit_root == root->node) {
WARN_ON(root->node->start !=
btrfs_root_bytenr(&root->root_item));
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
root->dirty_root = NULL;
spin_lock(&root->list_lock);
list_del_init(&dirty->root->dead_list);
spin_unlock(&root->list_lock);
kfree(dirty->root);
kfree(dirty);
/* make sure to update the root on disk
* so we get any updates to the block used
* counts
*/
err = btrfs_update_root(trans,
root->fs_info->tree_root,
&root->root_key,
&root->root_item);
continue;
}
memset(&root->root_item.drop_progress, 0,
sizeof(struct btrfs_disk_key));
root->root_item.drop_level = 0;
root->commit_root = NULL;
root->dirty_root = NULL;
root->root_key.offset = root->fs_info->generation;
btrfs_set_root_bytenr(&root->root_item,
root->node->start);
btrfs_set_root_level(&root->root_item,
btrfs_header_level(root->node));
btrfs_set_root_generation(&root->root_item,
root->root_key.offset);
err = btrfs_insert_root(trans, root->fs_info->tree_root,
&root->root_key,
&root->root_item);
if (err)
break;
refs = btrfs_root_refs(&dirty->root->root_item);
btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
err = btrfs_update_root(trans, root->fs_info->tree_root,
&dirty->root->root_key,
&dirty->root->root_item);
BUG_ON(err);
if (refs == 1) {
list_add(&dirty->list, list);
} else {
WARN_ON(1);
free_extent_buffer(dirty->root->node);
kfree(dirty->root);
kfree(dirty);
}
}
}
return err;
}
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 transid = trans->transid;
int ret = 0;
struct btrfs_fs_info *fs_info = root->fs_info;
if (trans->fs_info->transaction_aborted)
return -EROFS;
/*
* Flush all accumulated delayed refs so that root-tree updates are
* consistent
*/
ret = btrfs_run_delayed_refs(trans, -1);
if (ret < 0)
goto error;
if (root->commit_root == root->node)
goto commit_tree;
if (root == root->fs_info->tree_root)
goto commit_tree;
if (root == root->fs_info->chunk_root)
goto commit_tree;
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
btrfs_set_root_bytenr(&root->root_item, root->node->start);
btrfs_set_root_generation(&root->root_item, trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
if (ret < 0)
goto error;
commit_tree:
ret = commit_tree_roots(trans, fs_info);
if (ret < 0)
goto error;
/*
* Ensure that all committed roots are properly accounted in the
* extent tree
*/
ret = btrfs_run_delayed_refs(trans, -1);
if (ret < 0)
goto error;
btrfs_write_dirty_block_groups(trans);
__commit_transaction(trans, root);
if (ret < 0)
goto error;
ret = write_ctree_super(trans);
btrfs_finish_extent_commit(trans);
kfree(trans);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = transid;
return ret;
error:
btrfs_destroy_delayed_refs(trans);
free(trans);
return ret;
}
