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@@ -0,0 +1,199 @@
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+#include <linux/module.h>
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+#include <linux/fs.h>
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+#include "ctree.h"
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+#include "disk-io.h"
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+#include "transaction.h"
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+
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+
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+static void put_transaction(struct btrfs_transaction *transaction)
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+{
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+ transaction->use_count--;
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+ if (transaction->use_count == 0)
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+ kfree(transaction);
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+}
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+
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+static int join_transaction(struct btrfs_root *root)
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+{
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+ struct btrfs_transaction *cur_trans;
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+ cur_trans = root->fs_info->running_transaction;
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+ if (!cur_trans) {
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+ cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS);
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+ BUG_ON(!cur_trans);
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+ root->fs_info->running_transaction = cur_trans;
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+ cur_trans->num_writers = 0;
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+ cur_trans->transid = root->root_key.offset + 1;
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+ init_waitqueue_head(&cur_trans->writer_wait);
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+ init_waitqueue_head(&cur_trans->commit_wait);
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+ cur_trans->in_commit = 0;
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+ cur_trans->use_count = 0;
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+ cur_trans->commit_done = 0;
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+ }
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+ cur_trans->num_writers++;
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+ return 0;
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+}
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+
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+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
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+ int num_blocks)
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+{
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+ struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS);
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+ int ret;
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+
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+ mutex_lock(&root->fs_info->trans_mutex);
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+ ret = join_transaction(root);
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+ BUG_ON(ret);
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+ h->transid = root->fs_info->running_transaction->transid;
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+ h->transaction = root->fs_info->running_transaction;
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+ h->blocks_reserved = num_blocks;
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+ h->blocks_used = 0;
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+ root->fs_info->running_transaction->use_count++;
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+ return h;
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+}
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+
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+int btrfs_end_transaction(struct btrfs_trans_handle *trans,
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+ struct btrfs_root *root)
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+{
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+ struct btrfs_transaction *cur_trans;
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+ mutex_lock(&root->fs_info->trans_mutex);
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+ cur_trans = root->fs_info->running_transaction;
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+ WARN_ON(cur_trans->num_writers <= 1);
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+ if (waitqueue_active(&cur_trans->writer_wait))
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+ wake_up(&cur_trans->writer_wait);
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+ cur_trans->num_writers--;
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+ put_transaction(cur_trans);
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+ kfree(trans);
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+ return 0;
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+}
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+
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+
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+int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
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+ struct btrfs_root *root)
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+{
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+ filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping);
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+ return 0;
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+}
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+
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+int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
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+ struct btrfs_root *root)
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+{
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+ int ret;
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+ u64 old_extent_block;
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+ struct btrfs_fs_info *fs_info = root->fs_info;
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+ struct btrfs_root *tree_root = fs_info->tree_root;
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+ struct btrfs_root *extent_root = fs_info->extent_root;
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+ struct btrfs_root *inode_root = fs_info->inode_root;
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+
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+ btrfs_set_root_blocknr(&inode_root->root_item,
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+ inode_root->node->b_blocknr);
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+ ret = btrfs_update_root(trans, tree_root,
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+ &inode_root->root_key,
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+ &inode_root->root_item);
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+ BUG_ON(ret);
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+ while(1) {
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+ old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
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+ if (old_extent_block == extent_root->node->b_blocknr)
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+ break;
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+ btrfs_set_root_blocknr(&extent_root->root_item,
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+ extent_root->node->b_blocknr);
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+ ret = btrfs_update_root(trans, tree_root,
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+ &extent_root->root_key,
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+ &extent_root->root_item);
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+ BUG_ON(ret);
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+ }
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+ return 0;
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+}
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+
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+static int wait_for_commit(struct btrfs_root *root,
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+ struct btrfs_transaction *commit)
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+{
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+ DEFINE_WAIT(wait);
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+ commit->use_count++;
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+ while(!commit->commit_done) {
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+ prepare_to_wait(&commit->commit_wait, &wait,
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+ TASK_UNINTERRUPTIBLE);
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+ if (commit->commit_done)
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+ break;
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+ schedule();
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+ mutex_lock(&root->fs_info->trans_mutex);
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+ }
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+ finish_wait(&commit->commit_wait, &wait);
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+ return 0;
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+}
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+
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+int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
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+ struct btrfs_root *root)
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+{
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+ int ret = 0;
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+ struct buffer_head *snap = root->commit_root;
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+ struct btrfs_key snap_key;
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+ struct btrfs_transaction *cur_trans;
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+ DEFINE_WAIT(wait);
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+
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+ mutex_lock(&root->fs_info->trans_mutex);
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+ if (trans->transaction->in_commit) {
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+ cur_trans = trans->transaction;
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+ trans->transaction->use_count++;
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+ btrfs_end_transaction(trans, root);
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+ ret = wait_for_commit(root, cur_trans);
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+ BUG_ON(ret);
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+ put_transaction(cur_trans);
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+ return 0;
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+ }
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+ while (trans->transaction->num_writers > 1) {
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+ prepare_to_wait(&trans->transaction->writer_wait, &wait,
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+ TASK_UNINTERRUPTIBLE);
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+ if (trans->transaction->num_writers <= 1)
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+ break;
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+ schedule();
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+ mutex_lock(&root->fs_info->trans_mutex);
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+ }
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+ finish_wait(&trans->transaction->writer_wait, &wait);
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+
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+ cur_trans = root->fs_info->running_transaction;
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+ root->fs_info->running_transaction = NULL;
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+ mutex_unlock(&root->fs_info->trans_mutex);
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+
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+ memcpy(&snap_key, &root->root_key, sizeof(snap_key));
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+ root->root_key.offset++;
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+
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+ if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) {
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+ btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr);
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+ ret = btrfs_insert_root(trans, root->fs_info->tree_root,
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+ &root->root_key, &root->root_item);
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+ BUG_ON(ret);
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+ }
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+
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+ ret = btrfs_commit_tree_roots(trans, root);
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+ BUG_ON(ret);
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+
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+ ret = btrfs_write_and_wait_transaction(trans, root);
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+ BUG_ON(ret);
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+
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+ write_ctree_super(trans, root);
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+ btrfs_finish_extent_commit(trans, root->fs_info->extent_root);
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+ btrfs_finish_extent_commit(trans, root->fs_info->tree_root);
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+ put_transaction(cur_trans);
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+ kfree(trans);
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+
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+ if (root->node != root->commit_root) {
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+ trans = btrfs_start_transaction(root, 1);
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+ root->commit_root = root->node;
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+ get_bh(root->node);
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+ ret = btrfs_drop_snapshot(trans, root, snap);
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+ BUG_ON(ret);
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+
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+ ret = btrfs_del_root(trans, root->fs_info->tree_root,
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+ &snap_key);
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+ BUG_ON(ret);
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+ root->fs_info->generation = root->root_key.offset + 1;
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+ ret = btrfs_end_transaction(trans, root);
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+ BUG_ON(ret);
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+ }
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+
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+ return ret;
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+}
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+
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Chris Mason