Btrfs: do extent allocation and reference count updates in the background

[linux-2.6-omap-h63xx.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index d638c54d39e9b7edff5d0d64f2ed15ef062d6a7a..f94c2ad8996c4e7e8cff2d1546d412c6b6e9b139 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -65,6 +65,12 @@ static noinline int join_transaction(struct btrfs_root *root)
                cur_trans->use_count = 1;
                cur_trans->commit_done = 0;
                cur_trans->start_time = get_seconds();
+
+               cur_trans->delayed_refs.root.rb_node = NULL;
+               cur_trans->delayed_refs.num_entries = 0;
+               cur_trans->delayed_refs.flushing = 0;
+               spin_lock_init(&cur_trans->delayed_refs.lock);
+
                INIT_LIST_HEAD(&cur_trans->pending_snapshots);
                list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
                extent_io_tree_init(&cur_trans->dirty_pages,
@@ -182,6 +188,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
        h->block_group = 0;
        h->alloc_exclude_nr = 0;
        h->alloc_exclude_start = 0;
+       h->delayed_ref_updates = 0;
        root->fs_info->running_transaction->use_count++;
        mutex_unlock(&root->fs_info->trans_mutex);
        return h;
@@ -281,6 +288,14 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
        struct btrfs_transaction *cur_trans;
        struct btrfs_fs_info *info = root->fs_info;
 
+       if (trans->delayed_ref_updates &&
+           (trans->transaction->delayed_refs.flushing ||
+           trans->transaction->delayed_refs.num_entries > 16384)) {
+               btrfs_run_delayed_refs(trans, root, trans->delayed_ref_updates);
+       } else if (trans->transaction->delayed_refs.num_entries > 64) {
+               wake_up_process(root->fs_info->transaction_kthread);
+       }
+
        mutex_lock(&info->trans_mutex);
        cur_trans = info->running_transaction;
        WARN_ON(cur_trans != trans->transaction);
@@ -424,9 +439,10 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
        u64 old_root_bytenr;
        struct btrfs_root *tree_root = root->fs_info->tree_root;
 
-       btrfs_extent_post_op(trans, root);
        btrfs_write_dirty_block_groups(trans, root);
-       btrfs_extent_post_op(trans, root);
+
+       ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+       BUG_ON(ret);
 
        while (1) {
                old_root_bytenr = btrfs_root_bytenr(&root->root_item);
@@ -438,14 +454,14 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
                                     btrfs_header_level(root->node));
                btrfs_set_root_generation(&root->root_item, trans->transid);
 
-               btrfs_extent_post_op(trans, root);
-
                ret = btrfs_update_root(trans, tree_root,
                                        &root->root_key,
                                        &root->root_item);
                BUG_ON(ret);
                btrfs_write_dirty_block_groups(trans, root);
-               btrfs_extent_post_op(trans, root);
+
+               ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+               BUG_ON(ret);
        }
        return 0;
 }
@@ -459,15 +475,18 @@ int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
        struct btrfs_fs_info *fs_info = root->fs_info;
        struct list_head *next;
        struct extent_buffer *eb;
+       int ret;
 
-       btrfs_extent_post_op(trans, fs_info->tree_root);
+       ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+       BUG_ON(ret);
 
        eb = btrfs_lock_root_node(fs_info->tree_root);
        btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
        btrfs_tree_unlock(eb);
        free_extent_buffer(eb);
 
-       btrfs_extent_post_op(trans, fs_info->tree_root);
+       ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+       BUG_ON(ret);
 
        while (!list_empty(&fs_info->dirty_cowonly_roots)) {
                next = fs_info->dirty_cowonly_roots.next;
@@ -475,6 +494,9 @@ int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
                root = list_entry(next, struct btrfs_root, dirty_list);
 
                update_cowonly_root(trans, root);
+
+               ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+               BUG_ON(ret);
        }
        return 0;
 }
@@ -895,6 +917,21 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        DEFINE_WAIT(wait);
        int ret;
 
+       /* make a pass through all the delayed refs we have so far
+        * any runnings procs may add more while we are here
+        */
+       ret = btrfs_run_delayed_refs(trans, root, 0);
+       BUG_ON(ret);
+
+       /*
+        * set the flushing flag so procs in this transaction have to
+        * start sending their work down.
+        */
+       trans->transaction->delayed_refs.flushing = 1;
+
+       ret = btrfs_run_delayed_refs(trans, root, (u64)-1);
+       BUG_ON(ret);
+
        INIT_LIST_HEAD(&dirty_fs_roots);
        mutex_lock(&root->fs_info->trans_mutex);
        if (trans->transaction->in_commit) {
@@ -969,6 +1006,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
        ret = create_pending_snapshots(trans, root->fs_info);
        BUG_ON(ret);
 
+       ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+       BUG_ON(ret);
+
        WARN_ON(cur_trans != trans->transaction);
 
        /* btrfs_commit_tree_roots is responsible for getting the