3 files changed, 100 insertions, 67 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6d6e1ac0a9a0..10cece11dbd8 100644
--- 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);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3ed5868e7c0f..dc9865323e38 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -66,6 +66,7 @@ static int join_transaction(struct btrfs_root *root)
                 cur_trans->use_count = 1;
                 cur_trans->commit_done = 0;
                 cur_trans->start_time = get_seconds();
+                INIT_LIST_HEAD(&cur_trans->pending_snapshots);
                 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
                 btrfs_ordered_inode_tree_init(&cur_trans->ordered_inode_tree);
                 extent_map_tree_init(&cur_trans->dirty_pages,
@@ -481,10 +482,8 @@ int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
         struct inode *inode;
         u64 root_objectid = 0;
         u64 objectid = 0;
-        u64 transid = trans->transid;
         int ret;
 
-printk("write ordered trans %Lu\n", transid);
         while(1) {
                 ret = btrfs_find_first_ordered_inode(
                                 &cur_trans->ordered_inode_tree,
@@ -524,7 +523,80 @@ printk("write ordered trans %Lu\n", transid);
                 mutex_lock(&root->fs_info->fs_mutex);
                 mutex_lock(&root->fs_info->trans_mutex);
         }
-printk("done write ordered trans %Lu\n", transid);
+        return 0;
+}
+
+static int create_pending_snapshot(struct btrfs_trans_handle *trans,
+                                   struct btrfs_fs_info *fs_info,
+                                   struct btrfs_pending_snapshot *pending)
+{
+        struct btrfs_key key;
+        struct btrfs_root_item new_root_item;
+        struct btrfs_root *tree_root = fs_info->tree_root;
+        struct btrfs_root *root = pending->root;
+        struct extent_buffer *tmp;
+        int ret;
+        u64 objectid;
+
+        ret = btrfs_find_free_objectid(trans, 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);
+
+        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);
+        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,
+                                    pending->name, strlen(pending->name),
+                                    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,
+                             pending->name, strlen(pending->name), objectid,
+                             root->fs_info->sb->s_root->d_inode->i_ino);
+fail:
+        return ret;
+}
+
+static int create_pending_snapshots(struct btrfs_trans_handle *trans,
+                                   struct btrfs_fs_info *fs_info)
+{
+        struct btrfs_pending_snapshot *pending;
+        struct list_head *head = &trans->transaction->pending_snapshots;
+        int ret;
+
+        while(!list_empty(head)) {
+                pending = list_entry(head->next,
+                                     struct btrfs_pending_snapshot, list);
+                ret = create_pending_snapshot(trans, fs_info, pending);
+                BUG_ON(ret);
+                list_del(&pending->list);
+                kfree(pending->name);
+                kfree(pending);
+        }
         return 0;
 }
 
@@ -610,6 +682,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         } while (cur_trans->num_writers > 1 ||
                  (cur_trans->num_joined != joined));
 
+        ret = create_pending_snapshots(trans, root->fs_info);
+        BUG_ON(ret);
+
         WARN_ON(cur_trans != trans->transaction);
 
         ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index c157ddbe9d1e..fd52e9b23922 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -34,6 +34,7 @@ struct btrfs_transaction {
         struct btrfs_ordered_inode_tree ordered_inode_tree;
         wait_queue_head_t writer_wait;
         wait_queue_head_t commit_wait;
+        struct list_head pending_snapshots;
 };
 
 struct btrfs_trans_handle {
@@ -46,6 +47,12 @@ struct btrfs_trans_handle {
         u64 alloc_exclude_nr;
 };
 
+struct btrfs_pending_snapshot {
+        struct btrfs_root *root;
+        char *name;
+        struct list_head list;
+};
+
 
 static inline void btrfs_set_trans_block_group(struct btrfs_trans_handle *trans,
                                                struct inode *inode)