1 files changed, 87 insertions, 18 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 498626470a04..338a7199363b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -29,6 +29,7 @@ extern struct kmem_cache *btrfs_transaction_cachep;
 static struct workqueue_struct *trans_wq;
 
 #define BTRFS_ROOT_TRANS_TAG 0
+#define BTRFS_ROOT_DEFRAG_TAG 1
 
 static void put_transaction(struct btrfs_transaction *transaction)
 {
@@ -69,35 +70,41 @@ static int join_transaction(struct btrfs_root *root)
         return 0;
 }
 
+static int record_root_in_trans(struct btrfs_root *root)
+{
+        u64 running_trans_id = root->fs_info->running_transaction->transid;
+        if (root->ref_cows && root->last_trans < running_trans_id) {
+                WARN_ON(root == root->fs_info->extent_root);
+                if (root->root_item.refs != 0) {
+                        radix_tree_tag_set(&root->fs_info->fs_roots_radix,
+                                   (unsigned long)root->root_key.objectid,
+                                   BTRFS_ROOT_TRANS_TAG);
+                        radix_tree_tag_set(&root->fs_info->fs_roots_radix,
+                                   (unsigned long)root->root_key.objectid,
+                                   BTRFS_ROOT_DEFRAG_TAG);
+                        root->commit_root = root->node;
+                        get_bh(root->node);
+                } else {
+                        WARN_ON(1);
+                }
+                root->last_trans = running_trans_id;
+        }
+        return 0;
+}
+
 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
                                                    int num_blocks)
 {
         struct btrfs_trans_handle *h =
                 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
         int ret;
-        u64 running_trans_id;
 
         mutex_lock(&root->fs_info->trans_mutex);
         ret = join_transaction(root);
         BUG_ON(ret);
-        running_trans_id = root->fs_info->running_transaction->transid;
 
-        if (root != root->fs_info->tree_root && root->last_trans <
-            running_trans_id) {
-                WARN_ON(root == root->fs_info->extent_root);
-                WARN_ON(root->ref_cows != 1);
-                if (root->root_item.refs != 0) {
-                        radix_tree_tag_set(&root->fs_info->fs_roots_radix,
-                                           (unsigned long)root->root_key.objectid,
-                                           BTRFS_ROOT_TRANS_TAG);
-                        root->commit_root = root->node;
-                        get_bh(root->node);
-                } else {
-                        WARN_ON(1);
-                }
-        }
-        root->last_trans = running_trans_id;
-        h->transid = running_trans_id;
+        record_root_in_trans(root);
+        h->transid = root->fs_info->running_transaction->transid;
         h->transaction = root->fs_info->running_transaction;
         h->blocks_reserved = num_blocks;
         h->blocks_used = 0;
@@ -155,6 +162,15 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
                                               gang[i]);
                         if (!page)
                                 continue;
+                        if (PageWriteback(page)) {
+                                if (PageDirty(page))
+                                        wait_on_page_writeback(page);
+                                else {
+                                        unlock_page(page);
+                                        page_cache_release(page);
+                                        continue;
+                                }
+                        }
                         err = write_one_page(page, 0);
                         if (err)
                                 werr = err;
@@ -299,6 +315,58 @@ static int add_dirty_roots(struct btrfs_trans_handle *trans,
         return err;
 }
 
+int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
+{
+        struct btrfs_root *gang[1];
+        struct btrfs_root *root;
+        struct btrfs_root *tree_root = info->tree_root;
+        struct btrfs_trans_handle *trans;
+        int i;
+        int ret;
+        int err = 0;
+        u64 last = 0;
+
+        trans = btrfs_start_transaction(tree_root, 1);
+        while(1) {
+                ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
+                                                 (void **)gang, last,
+                                                 ARRAY_SIZE(gang),
+                                                 BTRFS_ROOT_DEFRAG_TAG);
+                if (ret == 0)
+                        break;
+                for (i = 0; i < ret; i++) {
+                        root = gang[i];
+                        last = root->root_key.objectid + 1;
+                        radix_tree_tag_clear(&info->fs_roots_radix,
+                                     (unsigned long)root->root_key.objectid,
+                                     BTRFS_ROOT_DEFRAG_TAG);
+                        if (root->defrag_running)
+                                continue;
+
+                        while (1) {
+                                mutex_lock(&root->fs_info->trans_mutex);
+                                record_root_in_trans(root);
+                                mutex_unlock(&root->fs_info->trans_mutex);
+
+                                root->defrag_running = 1;
+                                err = btrfs_defrag_leaves(trans, root, 1);
+                                btrfs_end_transaction(trans, tree_root);
+                                mutex_unlock(&info->fs_mutex);
+
+                                btrfs_btree_balance_dirty(root);
+
+                                mutex_lock(&info->fs_mutex);
+                                trans = btrfs_start_transaction(tree_root, 1);
+                                if (err != -EAGAIN)
+                                        break;
+                        }
+                        root->defrag_running = 0;
+                }
+        }
+        btrfs_end_transaction(trans, tree_root);
+        return err;
+}
+
 static int drop_dirty_roots(struct btrfs_root *tree_root,
                             struct list_head *list)
 {
@@ -475,6 +543,7 @@ void btrfs_transaction_cleaner(struct work_struct *work)
                 goto out;
         }
         mutex_unlock(&root->fs_info->trans_mutex);
+        btrfs_defrag_dirty_roots(root->fs_info);
         trans = btrfs_start_transaction(root, 1);
         ret = btrfs_commit_transaction(trans, root);
 out: