Btrfs: Move snapshot creation to commit time

[linux-2.6-block.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6d6e1ac0a9a0aa55c0ee5816dad736a7beca0e8d..10cece11dbd832eef404621bdc8200f62f2e34e3 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2250,13 +2250,10 @@ fail_commit:
 
 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
 {
+       struct btrfs_pending_snapshot *pending_snapshot;
        struct btrfs_trans_handle *trans;
-       struct btrfs_key key;
-       struct btrfs_root_item new_root_item;
-       struct extent_buffer *tmp;
        int ret;
        int err;
-       u64 objectid;
        unsigned long nr = 0;
 
        if (!root->ref_cows)
@@ -2267,72 +2264,26 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
        if (ret)
                goto fail_unlock;
 
+       pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
+       if (!pending_snapshot) {
+               ret = -ENOMEM;
+               goto fail_unlock;
+       }
+       pending_snapshot->name = kstrndup(name, namelen, GFP_NOFS);
+       if (!pending_snapshot->name) {
+               ret = -ENOMEM;
+               kfree(pending_snapshot);
+               goto fail_unlock;
+       }
        trans = btrfs_start_transaction(root, 1);
        BUG_ON(!trans);
-       err = btrfs_commit_transaction(trans, root);
-
-       trans = btrfs_start_transaction(root, 1);
 
+       pending_snapshot->root = root;
+       list_add(&pending_snapshot->list,
+                &trans->transaction->pending_snapshots);
        ret = btrfs_update_inode(trans, root, root->inode);
-       if (ret)
-               goto fail;
-
-       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
-                                      0, &objectid);
-       if (ret)
-               goto fail; memcpy(&new_root_item, &root->root_item,
-              sizeof(new_root_item));
-
-       key.objectid = objectid;
-       key.offset = 1;
-       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
-
-       extent_buffer_get(root->node);
-       btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
-       free_extent_buffer(tmp);
-
-       /* write the ordered inodes to force all delayed allocations to
-        * be filled.  Once this is done, we can copy the root
-        */
-       mutex_lock(&root->fs_info->trans_mutex);
-       btrfs_write_ordered_inodes(trans, root);
-       mutex_unlock(&root->fs_info->trans_mutex);
-
-       btrfs_copy_root(trans, root, root->node, &tmp, objectid);
-
-       btrfs_set_root_bytenr(&new_root_item, tmp->start);
-       btrfs_set_root_level(&new_root_item, btrfs_header_level(tmp));
-       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
-                               &new_root_item);
-printk("new root %Lu node %Lu\n", objectid, tmp->start);
-       free_extent_buffer(tmp);
-       if (ret)
-               goto fail;
-
-       /*
-        * insert the directory item
-        */
-       key.offset = (u64)-1;
-       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
-                                   name, namelen,
-                                   root->fs_info->sb->s_root->d_inode->i_ino,
-                                   &key, BTRFS_FT_DIR);
-
-       if (ret)
-               goto fail;
-
-       ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
-                            name, namelen, objectid,
-                            root->fs_info->sb->s_root->d_inode->i_ino);
-
-       if (ret)
-               goto fail;
-fail:
-       nr = trans->blocks_used;
        err = btrfs_commit_transaction(trans, root);
 
-       if (err && !ret)
-               ret = err;
 fail_unlock:
        mutex_unlock(&root->fs_info->fs_mutex);
        btrfs_btree_balance_dirty(root, nr);