Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: try to free metadata pages when we free btree blocks
  Btrfs: add extra flushing for renames and truncates
  Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod
  Btrfs: optimize fsyncs on old files
  Btrfs: tree logging unlink/rename fixes
  Btrfs: Make sure i_nlink doesn't hit zero too soon during log replay
  Btrfs: limit balancing work while flushing delayed refs
  Btrfs: readahead checksums during btrfs_finish_ordered_io
  Btrfs: leave btree locks spinning more often
  Btrfs: Only let very young transactions grow during commit
  Btrfs: Check for a blocking lock before taking the spin
  Btrfs: reduce stack in cow_file_range
  Btrfs: reduce stalls during transaction commit
  Btrfs: process the delayed reference queue in clusters
  Btrfs: try to cleanup delayed refs while freeing extents
  Btrfs: reduce stack usage in some crucial tree balancing functions
  Btrfs: do extent allocation and reference count updates in the background
  Btrfs: don't preallocate metadata blocks during btrfs_search_slot

fs/btrfs/Makefile

@@ -8,7 +8,7 @@ btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
 	   extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
 	   ref-cache.o export.o tree-log.o acl.o free-space-cache.o zlib.o \
-	   compression.o
+	   compression.o delayed-ref.o
 else
 
 # Normal Makefile

fs/btrfs/btrfs_inode.h

@@ -66,6 +66,12 @@ struct btrfs_inode {
 	 */
 	struct list_head delalloc_inodes;
 
+	/*
+	 * list for tracking inodes that must be sent to disk before a
+	 * rename or truncate commit
+	 */
+	struct list_head ordered_operations;
+
 	/* the space_info for where this inode's data allocations are done */
 	struct btrfs_space_info *space_info;
 
@@ -86,12 +92,6 @@ struct btrfs_inode {
 	 */
 	u64 logged_trans;
 
-	/*
-	 * trans that last made a change that should be fully fsync'd.  This
-	 * gets reset to zero each time the inode is logged
-	 */
-	u64 log_dirty_trans;
-
 	/* total number of bytes pending delalloc, used by stat to calc the
 	 * real block usage of the file
 	 */
@@ -121,6 +121,25 @@ struct btrfs_inode {
 	/* the start of block group preferred for allocations. */
 	u64 block_group;
 
+	/* the fsync log has some corner cases that mean we have to check
+	 * directories to see if any unlinks have been done before
+	 * the directory was logged.  See tree-log.c for all the
+	 * details
+	 */
+	u64 last_unlink_trans;
+
+	/*
+	 * ordered_data_close is set by truncate when a file that used
+	 * to have good data has been truncated to zero.  When it is set
+	 * the btrfs file release call will add this inode to the
+	 * ordered operations list so that we make sure to flush out any
+	 * new data the application may have written before commit.
+	 *
+	 * yes, its silly to have a single bitflag, but we might grow more
+	 * of these.
+	 */
+	unsigned ordered_data_close:1;
+
 	struct inode vfs_inode;
 };
 

fs/btrfs/ctree.c

@@ -254,18 +254,13 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
  * empty_size -- a hint that you plan on doing more cow.  This is the size in
  * bytes the allocator should try to find free next to the block it returns.
  * This is just a hint and may be ignored by the allocator.
- *
- * prealloc_dest -- if you have already reserved a destination for the cow,
- * this uses that block instead of allocating a new one.
- * btrfs_alloc_reserved_extent is used to finish the allocation.
  */
 static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct extent_buffer *buf,
 			     struct extent_buffer *parent, int parent_slot,
 			     struct extent_buffer **cow_ret,
-			     u64 search_start, u64 empty_size,
-			     u64 prealloc_dest)
+			     u64 search_start, u64 empty_size)
 {
 	u64 parent_start;
 	struct extent_buffer *cow;
@@ -291,26 +286,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	level = btrfs_header_level(buf);
 	nritems = btrfs_header_nritems(buf);
 
-	if (prealloc_dest) {
-		struct btrfs_key ins;
-
-		ins.objectid = prealloc_dest;
-		ins.offset = buf->len;
-		ins.type = BTRFS_EXTENT_ITEM_KEY;
-
-		ret = btrfs_alloc_reserved_extent(trans, root, parent_start,
-						  root->root_key.objectid,
-						  trans->transid, level, &ins);
-		BUG_ON(ret);
-		cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
-					    buf->len, level);
-	} else {
-		cow = btrfs_alloc_free_block(trans, root, buf->len,
-					     parent_start,
-					     root->root_key.objectid,
-					     trans->transid, level,
-					     search_start, empty_size);
-	}
+	cow = btrfs_alloc_free_block(trans, root, buf->len,
+				     parent_start, root->root_key.objectid,
+				     trans->transid, level,
+				     search_start, empty_size);
 	if (IS_ERR(cow))
 		return PTR_ERR(cow);
 
@@ -413,7 +392,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 		    struct btrfs_root *root, struct extent_buffer *buf,
 		    struct extent_buffer *parent, int parent_slot,
-		    struct extent_buffer **cow_ret, u64 prealloc_dest)
+		    struct extent_buffer **cow_ret)
 {
 	u64 search_start;
 	int ret;
@@ -436,7 +415,6 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 	    btrfs_header_owner(buf) == root->root_key.objectid &&
 	    !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
 		*cow_ret = buf;
-		WARN_ON(prealloc_dest);
 		return 0;
 	}
 
@@ -447,8 +425,7 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 	btrfs_set_lock_blocking(buf);
 
 	ret = __btrfs_cow_block(trans, root, buf, parent,
-				 parent_slot, cow_ret, search_start, 0,
-				 prealloc_dest);
+				 parent_slot, cow_ret, search_start, 0);
 	return ret;
 }
 
@@ -617,7 +594,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 		err = __btrfs_cow_block(trans, root, cur, parent, i,
 					&cur, search_start,
 					min(16 * blocksize,
-					    (end_slot - i) * blocksize), 0);
+					    (end_slot - i) * blocksize));
 		if (err) {
 			btrfs_tree_unlock(cur);
 			free_extent_buffer(cur);
@@ -937,7 +914,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		BUG_ON(!child);
 		btrfs_tree_lock(child);
 		btrfs_set_lock_blocking(child);
-		ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
+		ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
 		BUG_ON(ret);
 
 		spin_lock(&root->node_lock);
@@ -945,6 +922,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		spin_unlock(&root->node_lock);
 
 		ret = btrfs_update_extent_ref(trans, root, child->start,
+					      child->len,
 					      mid->start, child->start,
 					      root->root_key.objectid,
 					      trans->transid, level - 1);
@@ -971,6 +949,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 	    BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
 		return 0;
 
+	if (trans->transaction->delayed_refs.flushing &&
+	    btrfs_header_nritems(mid) > 2)
+		return 0;
+
 	if (btrfs_header_nritems(mid) < 2)
 		err_on_enospc = 1;
 
@@ -979,7 +961,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		btrfs_tree_lock(left);
 		btrfs_set_lock_blocking(left);
 		wret = btrfs_cow_block(trans, root, left,
-				       parent, pslot - 1, &left, 0);
+				       parent, pslot - 1, &left);
 		if (wret) {
 			ret = wret;
 			goto enospc;
@@ -990,7 +972,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		btrfs_tree_lock(right);
 		btrfs_set_lock_blocking(right);
 		wret = btrfs_cow_block(trans, root, right,
-				       parent, pslot + 1, &right, 0);
+				       parent, pslot + 1, &right);
 		if (wret) {
 			ret = wret;
 			goto enospc;
@@ -1171,7 +1153,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 			wret = 1;
 		} else {
 			ret = btrfs_cow_block(trans, root, left, parent,
-					      pslot - 1, &left, 0);
+					      pslot - 1, &left);
 			if (ret)
 				wret = 1;
 			else {
@@ -1222,7 +1204,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 		} else {
 			ret = btrfs_cow_block(trans, root, right,
 					      parent, pslot + 1,
-					      &right, 0);
+					      &right);
 			if (ret)
 				wret = 1;
 			else {
@@ -1492,7 +1474,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
 	u8 lowest_level = 0;
 	u64 blocknr;
 	u64 gen;
-	struct btrfs_key prealloc_block;
 
 	lowest_level = p->lowest_level;
 	WARN_ON(lowest_level && ins_len > 0);
@@ -1501,8 +1482,6 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (ins_len < 0)
 		lowest_unlock = 2;
 
-	prealloc_block.objectid = 0;
-
 again:
 	if (p->skip_locking)
 		b = btrfs_root_node(root);
@@ -1529,44 +1508,11 @@ again:
 			    !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
 				goto cow_done;
 			}
-
-			/* ok, we have to cow, is our old prealloc the right
-			 * size?
-			 */
-			if (prealloc_block.objectid &&
-			    prealloc_block.offset != b->len) {
-				btrfs_release_path(root, p);
-				btrfs_free_reserved_extent(root,
-					   prealloc_block.objectid,
-					   prealloc_block.offset);
-				prealloc_block.objectid = 0;
-				goto again;
-			}
-
-			/*
-			 * for higher level blocks, try not to allocate blocks
-			 * with the block and the parent locks held.
-			 */
-			if (level > 0 && !prealloc_block.objectid) {
-				u32 size = b->len;
-				u64 hint = b->start;
-
-				btrfs_release_path(root, p);
-				ret = btrfs_reserve_extent(trans, root,
-							   size, size, 0,
-							   hint, (u64)-1,
-							   &prealloc_block, 0);
-				BUG_ON(ret);
-				goto again;
-			}
-
 			btrfs_set_path_blocking(p);
 
 			wret = btrfs_cow_block(trans, root, b,
 					       p->nodes[level + 1],
-					       p->slots[level + 1],
-					       &b, prealloc_block.objectid);
-			prealloc_block.objectid = 0;
+					       p->slots[level + 1], &b);
 			if (wret) {
 				free_extent_buffer(b);
 				ret = wret;
@@ -1742,12 +1688,8 @@ done:
 	 * we don't really know what they plan on doing with the path
 	 * from here on, so for now just mark it as blocking
 	 */
-	btrfs_set_path_blocking(p);
-	if (prealloc_block.objectid) {
-		btrfs_free_reserved_extent(root,
-			   prealloc_block.objectid,
-			   prealloc_block.offset);
-	}
+	if (!p->leave_spinning)
+		btrfs_set_path_blocking(p);
 	return ret;
 }
 
@@ -1768,7 +1710,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
 	int ret;
 
 	eb = btrfs_lock_root_node(root);
-	ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
+	ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb);
 	BUG_ON(ret);
 
 	btrfs_set_lock_blocking(eb);
@@ -1826,7 +1768,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
 			}
 
 			ret = btrfs_cow_block(trans, root, eb, parent, slot,
-					      &eb, 0);
+					      &eb);
 			BUG_ON(ret);
 
 			if (root->root_key.objectid ==
@@ -2139,7 +2081,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 	spin_unlock(&root->node_lock);
 
 	ret = btrfs_update_extent_ref(trans, root, lower->start,
-				      lower->start, c->start,
+				      lower->len, lower->start, c->start,
 				      root->root_key.objectid,
 				      trans->transid, level - 1);
 	BUG_ON(ret);
@@ -2221,7 +2163,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
 		ret = insert_new_root(trans, root, path, level + 1);
 		if (ret)
 			return ret;
-	} else {
+	} else if (!trans->transaction->delayed_refs.flushing) {
 		ret = push_nodes_for_insert(trans, root, path, level);
 		c = path->nodes[level];
 		if (!ret && btrfs_header_nritems(c) <
@@ -2329,66 +2271,27 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root,
 	return ret;
 }
 
-/*
- * push some data in the path leaf to the right, trying to free up at
- * least data_size bytes.  returns zero if the push worked, nonzero otherwise
- *
- * returns 1 if the push failed because the other node didn't have enough
- * room, 0 if everything worked out and < 0 if there were major errors.
- */
-static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
-			   *root, struct btrfs_path *path, int data_size,
-			   int empty)
+static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
+				      struct btrfs_root *root,
+				      struct btrfs_path *path,
+				      int data_size, int empty,
+				      struct extent_buffer *right,
+				      int free_space, u32 left_nritems)
 {
 	struct extent_buffer *left = path->nodes[0];
-	struct extent_buffer *right;
-	struct extent_buffer *upper;
+	struct extent_buffer *upper = path->nodes[1];
 	struct btrfs_disk_key disk_key;
 	int slot;
 	u32 i;
-	int free_space;
 	int push_space = 0;
 	int push_items = 0;
 	struct btrfs_item *item;
-	u32 left_nritems;
 	u32 nr;
 	u32 right_nritems;
 	u32 data_end;
 	u32 this_item_size;
 	int ret;
 
-	slot = path->slots[1];
-	if (!path->nodes[1])
-		return 1;
-
-	upper = path->nodes[1];
-	if (slot >= btrfs_header_nritems(upper) - 1)
-		return 1;
-
-	btrfs_assert_tree_locked(path->nodes[1]);
-
-	right = read_node_slot(root, upper, slot + 1);
-	btrfs_tree_lock(right);
-	btrfs_set_lock_blocking(right);
-
-	free_space = btrfs_leaf_free_space(root, right);
-	if (free_space < data_size)
-		goto out_unlock;
-
-	/* cow and double check */
-	ret = btrfs_cow_block(trans, root, right, upper,
-			      slot + 1, &right, 0);
-	if (ret)
-		goto out_unlock;
-
-	free_space = btrfs_leaf_free_space(root, right);
-	if (free_space < data_size)
-		goto out_unlock;
-
-	left_nritems = btrfs_header_nritems(left);
-	if (left_nritems == 0)
-		goto out_unlock;
-
 	if (empty)
 		nr = 0;
 	else
@@ -2397,6 +2300,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (path->slots[0] >= left_nritems)
 		push_space += data_size;
 
+	slot = path->slots[1];
 	i = left_nritems - 1;
 	while (i >= nr) {
 		item = btrfs_item_nr(left, i);
@@ -2527,25 +2431,83 @@ out_unlock:
 	return 1;
 }
 
+/*
+ * push some data in the path leaf to the right, trying to free up at
+ * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+			   *root, struct btrfs_path *path, int data_size,
+			   int empty)
+{
+	struct extent_buffer *left = path->nodes[0];
+	struct extent_buffer *right;
+	struct extent_buffer *upper;
+	int slot;
+	int free_space;
+	u32 left_nritems;
+	int ret;
+
+	if (!path->nodes[1])
+		return 1;
+
+	slot = path->slots[1];
+	upper = path->nodes[1];
+	if (slot >= btrfs_header_nritems(upper) - 1)
+		return 1;
+
+	btrfs_assert_tree_locked(path->nodes[1]);
+
+	right = read_node_slot(root, upper, slot + 1);
+	btrfs_tree_lock(right);
+	btrfs_set_lock_blocking(right);
+
+	free_space = btrfs_leaf_free_space(root, right);
+	if (free_space < data_size)
+		goto out_unlock;
+
+	/* cow and double check */
+	ret = btrfs_cow_block(trans, root, right, upper,
+			      slot + 1, &right);
+	if (ret)
+		goto out_unlock;
+
+	free_space = btrfs_leaf_free_space(root, right);
+	if (free_space < data_size)
+		goto out_unlock;
+
+	left_nritems = btrfs_header_nritems(left);
+	if (left_nritems == 0)
+		goto out_unlock;
+
+	return __push_leaf_right(trans, root, path, data_size, empty,
+				right, free_space, left_nritems);
+out_unlock:
+	btrfs_tree_unlock(right);
+	free_extent_buffer(right);
+	return 1;
+}
+
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
  */
-static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, struct btrfs_path *path, int data_size,
-			  int empty)
+static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
+				     struct btrfs_root *root,
+				     struct btrfs_path *path, int data_size,
+				     int empty, struct extent_buffer *left,
+				     int free_space, int right_nritems)
 {
 	struct btrfs_disk_key disk_key;
 	struct extent_buffer *right = path->nodes[0];
-	struct extent_buffer *left;
 	int slot;
 	int i;
-	int free_space;
 	int push_space = 0;
 	int push_items = 0;
 	struct btrfs_item *item;
 	u32 old_left_nritems;
-	u32 right_nritems;
 	u32 nr;
 	int ret = 0;
 	int wret;
@@ -2553,41 +2515,6 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 	u32 old_left_item_size;
 
 	slot = path->slots[1];
-	if (slot == 0)
-		return 1;
-	if (!path->nodes[1])
-		return 1;
-
-	right_nritems = btrfs_header_nritems(right);
-	if (right_nritems == 0)
-		return 1;
-
-	btrfs_assert_tree_locked(path->nodes[1]);
-
-	left = read_node_slot(root, path->nodes[1], slot - 1);
-	btrfs_tree_lock(left);
-	btrfs_set_lock_blocking(left);
-
-	free_space = btrfs_leaf_free_space(root, left);
-	if (free_space < data_size) {
-		ret = 1;
-		goto out;
-	}
-
-	/* cow and double check */
-	ret = btrfs_cow_block(trans, root, left,
-			      path->nodes[1], slot - 1, &left, 0);
-	if (ret) {
-		/* we hit -ENOSPC, but it isn't fatal here */
-		ret = 1;
-		goto out;
-	}
-
-	free_space = btrfs_leaf_free_space(root, left);
-	if (free_space < data_size) {
-		ret = 1;
-		goto out;
-	}
 
 	if (empty)
 		nr = right_nritems;
@@ -2754,6 +2681,154 @@ out:
 	return ret;
 }
 
+/*
+ * push some data in the path leaf to the left, trying to free up at
+ * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ */
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+			  *root, struct btrfs_path *path, int data_size,
+			  int empty)
+{
+	struct extent_buffer *right = path->nodes[0];
+	struct extent_buffer *left;
+	int slot;
+	int free_space;
+	u32 right_nritems;
+	int ret = 0;
+
+	slot = path->slots[1];
+	if (slot == 0)
+		return 1;
+	if (!path->nodes[1])
+		return 1;
+
+	right_nritems = btrfs_header_nritems(right);
+	if (right_nritems == 0)
+		return 1;
+
+	btrfs_assert_tree_locked(path->nodes[1]);
+
+	left = read_node_slot(root, path->nodes[1], slot - 1);
+	btrfs_tree_lock(left);
+	btrfs_set_lock_blocking(left);
+
+	free_space = btrfs_leaf_free_space(root, left);
+	if (free_space < data_size) {
+		ret = 1;
+		goto out;
+	}
+
+	/* cow and double check */
+	ret = btrfs_cow_block(trans, root, left,
+			      path->nodes[1], slot - 1, &left);
+	if (ret) {
+		/* we hit -ENOSPC, but it isn't fatal here */
+		ret = 1;
+		goto out;
+	}
+
+	free_space = btrfs_leaf_free_space(root, left);
+	if (free_space < data_size) {
+		ret = 1;
+		goto out;
+	}
+
+	return __push_leaf_left(trans, root, path, data_size,
+			       empty, left, free_space, right_nritems);
+out:
+	btrfs_tree_unlock(left);
+	free_extent_buffer(left);
+	return ret;
+}
+
+/*
+ * split the path's leaf in two, making sure there is at least data_size
+ * available for the resulting leaf level of the path.
+ *
+ * returns 0 if all went well and < 0 on failure.
+ */
+static noinline int copy_for_split(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root,
+			       struct btrfs_path *path,
+			       struct extent_buffer *l,
+			       struct extent_buffer *right,
+			       int slot, int mid, int nritems)
+{
+	int data_copy_size;
+	int rt_data_off;
+	int i;
+	int ret = 0;
+	int wret;
+	struct btrfs_disk_key disk_key;
+
+	nritems = nritems - mid;
+	btrfs_set_header_nritems(right, nritems);
+	data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
+
+	copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
+			   btrfs_item_nr_offset(mid),
+			   nritems * sizeof(struct btrfs_item));
+
+	copy_extent_buffer(right, l,
+		     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+		     data_copy_size, btrfs_leaf_data(l) +
+		     leaf_data_end(root, l), data_copy_size);
+
+	rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
+		      btrfs_item_end_nr(l, mid);
+
+	for (i = 0; i < nritems; i++) {
+		struct btrfs_item *item = btrfs_item_nr(right, i);
+		u32 ioff;
+
+		if (!right->map_token) {
+			map_extent_buffer(right, (unsigned long)item,
+					sizeof(struct btrfs_item),
+					&right->map_token, &right->kaddr,
+					&right->map_start, &right->map_len,
+					KM_USER1);
+		}
+
+		ioff = btrfs_item_offset(right, item);
+		btrfs_set_item_offset(right, item, ioff + rt_data_off);
+	}
+
+	if (right->map_token) {
+		unmap_extent_buffer(right, right->map_token, KM_USER1);
+		right->map_token = NULL;
+	}
+
+	btrfs_set_header_nritems(l, mid);
+	ret = 0;
+	btrfs_item_key(right, &disk_key, 0);
+	wret = insert_ptr(trans, root, path, &disk_key, right->start,
+			  path->slots[1] + 1, 1);
+	if (wret)
+		ret = wret;
+
+	btrfs_mark_buffer_dirty(right);
+	btrfs_mark_buffer_dirty(l);
+	BUG_ON(path->slots[0] != slot);
+
+	ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+	BUG_ON(ret);
+
+	if (mid <= slot) {
+		btrfs_tree_unlock(path->nodes[0]);
+		free_extent_buffer(path->nodes[0]);
+		path->nodes[0] = right;
+		path->slots[0] -= mid;
+		path->slots[1] += 1;
+	} else {
+		btrfs_tree_unlock(right);
+		free_extent_buffer(right);
+	}
+
+	BUG_ON(path->slots[0] < 0);
+
+	return ret;
+}
+
 /*
  * split the path's leaf in two, making sure there is at least data_size
  * available for the resulting leaf level of the path.
@@ -2771,17 +2846,14 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
 	int mid;
 	int slot;
 	struct extent_buffer *right;
-	int data_copy_size;
-	int rt_data_off;
-	int i;
 	int ret = 0;
 	int wret;
 	int double_split;
 	int num_doubles = 0;
-	struct btrfs_disk_key disk_key;
 
 	/* first try to make some room by pushing left and right */
-	if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
+	if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY &&
+	    !trans->transaction->delayed_refs.flushing) {
 		wret = push_leaf_right(trans, root, path, data_size, 0);
 		if (wret < 0)
 			return wret;
@@ -2830,11 +2902,14 @@ again:
 	write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
 			    (unsigned long)btrfs_header_chunk_tree_uuid(right),
 			    BTRFS_UUID_SIZE);
+
 	if (mid <= slot) {
 		if (nritems == 1 ||
 		    leaf_space_used(l, mid, nritems - mid) + data_size >
 			BTRFS_LEAF_DATA_SIZE(root)) {
 			if (slot >= nritems) {
+				struct btrfs_disk_key disk_key;
+
 				btrfs_cpu_key_to_disk(&disk_key, ins_key);
 				btrfs_set_header_nritems(right, 0);
 				wret = insert_ptr(trans, root, path,
@@ -2862,6 +2937,8 @@ again:
 		if (leaf_space_used(l, 0, mid) + data_size >
 			BTRFS_LEAF_DATA_SIZE(root)) {
 			if (!extend && data_size && slot == 0) {
+				struct btrfs_disk_key disk_key;
+
 				btrfs_cpu_key_to_disk(&disk_key, ins_key);
 				btrfs_set_header_nritems(right, 0);
 				wret = insert_ptr(trans, root, path,
@@ -2894,76 +2971,16 @@ again:
 			}
 		}
 	}
-	nritems = nritems - mid;
-	btrfs_set_header_nritems(right, nritems);
-	data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
-
-	copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
-			   btrfs_item_nr_offset(mid),
-			   nritems * sizeof(struct btrfs_item));
-
-	copy_extent_buffer(right, l,
-		     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
-		     data_copy_size, btrfs_leaf_data(l) +
-		     leaf_data_end(root, l), data_copy_size);
-
-	rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
-		      btrfs_item_end_nr(l, mid);
-
-	for (i = 0; i < nritems; i++) {
-		struct btrfs_item *item = btrfs_item_nr(right, i);
-		u32 ioff;
-
-		if (!right->map_token) {
-			map_extent_buffer(right, (unsigned long)item,
-					sizeof(struct btrfs_item),
-					&right->map_token, &right->kaddr,
-					&right->map_start, &right->map_len,
-					KM_USER1);
-		}
-
-		ioff = btrfs_item_offset(right, item);
-		btrfs_set_item_offset(right, item, ioff + rt_data_off);
-	}
-
-	if (right->map_token) {
-		unmap_extent_buffer(right, right->map_token, KM_USER1);
-		right->map_token = NULL;
-	}
-
-	btrfs_set_header_nritems(l, mid);
-	ret = 0;
-	btrfs_item_key(right, &disk_key, 0);
-	wret = insert_ptr(trans, root, path, &disk_key, right->start,
-			  path->slots[1] + 1, 1);
-	if (wret)
-		ret = wret;
-
-	btrfs_mark_buffer_dirty(right);
-	btrfs_mark_buffer_dirty(l);
-	BUG_ON(path->slots[0] != slot);
 
-	ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+	ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
 	BUG_ON(ret);
 
-	if (mid <= slot) {
-		btrfs_tree_unlock(path->nodes[0]);
-		free_extent_buffer(path->nodes[0]);
-		path->nodes[0] = right;
-		path->slots[0] -= mid;
-		path->slots[1] += 1;
-	} else {
-		btrfs_tree_unlock(right);
-		free_extent_buffer(right);
-	}
-
-	BUG_ON(path->slots[0] < 0);
-
 	if (double_split) {
 		BUG_ON(num_doubles != 0);
 		num_doubles++;
 		goto again;
 	}
+
 	return ret;
 }
 
@@ -3021,26 +3038,27 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
 		return -EAGAIN;
 	}
 
+	btrfs_set_path_blocking(path);
 	ret = split_leaf(trans, root, &orig_key, path,
 			 sizeof(struct btrfs_item), 1);
 	path->keep_locks = 0;
 	BUG_ON(ret);
 
+	btrfs_unlock_up_safe(path, 1);
+	leaf = path->nodes[0];
+	BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
+
+split:
 	/*
 	 * make sure any changes to the path from split_leaf leave it
 	 * in a blocking state
 	 */
 	btrfs_set_path_blocking(path);
 
-	leaf = path->nodes[0];
-	BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
-
-split:
 	item = btrfs_item_nr(leaf, path->slots[0]);
 	orig_offset = btrfs_item_offset(leaf, item);
 	item_size = btrfs_item_size(leaf, item);
 
-
 	buf = kmalloc(item_size, GFP_NOFS);
 	read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
 			    path->slots[0]), item_size);
@@ -3445,39 +3463,27 @@ out:
 }
 
 /*
- * Given a key and some data, insert items into the tree.
- * This does all the path init required, making room in the tree if needed.
+ * this is a helper for btrfs_insert_empty_items, the main goal here is
+ * to save stack depth by doing the bulk of the work in a function
+ * that doesn't call btrfs_search_slot
  */
-int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root,
-			    struct btrfs_path *path,
-			    struct btrfs_key *cpu_key, u32 *data_size,
-			    int nr)
+static noinline_for_stack int
+setup_items_for_insert(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *root, struct btrfs_path *path,
+		      struct btrfs_key *cpu_key, u32 *data_size,
+		      u32 total_data, u32 total_size, int nr)
 {
-	struct extent_buffer *leaf;
 	struct btrfs_item *item;
-	int ret = 0;
-	int slot;
-	int slot_orig;
 	int i;
 	u32 nritems;
-	u32 total_size = 0;
-	u32 total_data = 0;
 	unsigned int data_end;
 	struct btrfs_disk_key disk_key;
+	int ret;
+	struct extent_buffer *leaf;
+	int slot;
 
-	for (i = 0; i < nr; i++)
-		total_data += data_size[i];
-
-	total_size = total_data + (nr * sizeof(struct btrfs_item));
-	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
-	if (ret == 0)
-		return -EEXIST;
-	if (ret < 0)
-		goto out;
-
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
+	slot = path->slots[0];
 
 	nritems = btrfs_header_nritems(leaf);
 	data_end = leaf_data_end(root, leaf);
@@ -3489,9 +3495,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 		BUG();
 	}
 
-	slot = path->slots[0];
-	BUG_ON(slot < 0);
-
 	if (slot != nritems) {
 		unsigned int old_data = btrfs_item_end_nr(leaf, slot);
 
@@ -3547,21 +3550,60 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 		data_end -= data_size[i];
 		btrfs_set_item_size(leaf, item, data_size[i]);
 	}
+
 	btrfs_set_header_nritems(leaf, nritems + nr);
-	btrfs_mark_buffer_dirty(leaf);
 
 	ret = 0;
 	if (slot == 0) {
+		struct btrfs_disk_key disk_key;
 		btrfs_cpu_key_to_disk(&disk_key, cpu_key);
 		ret = fixup_low_keys(trans, root, path, &disk_key, 1);
 	}
+	btrfs_unlock_up_safe(path, 1);
+	btrfs_mark_buffer_dirty(leaf);
 
 	if (btrfs_leaf_free_space(root, leaf) < 0) {
 		btrfs_print_leaf(root, leaf);
 		BUG();
 	}
+	return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root,
+			    struct btrfs_path *path,
+			    struct btrfs_key *cpu_key, u32 *data_size,
+			    int nr)
+{
+	struct extent_buffer *leaf;
+	int ret = 0;
+	int slot;
+	int i;
+	u32 total_size = 0;
+	u32 total_data = 0;
+
+	for (i = 0; i < nr; i++)
+		total_data += data_size[i];
+
+	total_size = total_data + (nr * sizeof(struct btrfs_item));
+	ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+	if (ret == 0)
+		return -EEXIST;
+	if (ret < 0)
+		goto out;
+
+	leaf = path->nodes[0];
+	slot = path->slots[0];
+	BUG_ON(slot < 0);
+
+	ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
+			       total_data, total_size, nr);
+
 out:
-	btrfs_unlock_up_safe(path, 1);
 	return ret;
 }
 
@@ -3749,7 +3791,8 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		}
 
 		/* delete the leaf if it is mostly empty */
-		if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
+		if (used < BTRFS_LEAF_DATA_SIZE(root) / 4 &&
+		    !trans->transaction->delayed_refs.flushing) {
 			/* push_leaf_left fixes the path.
 			 * make sure the path still points to our leaf
 			 * for possible call to del_ptr below
@@ -3757,6 +3800,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			slot = path->slots[1];
 			extent_buffer_get(leaf);
 
+			btrfs_set_path_blocking(path);
 			wret = push_leaf_left(trans, root, path, 1, 1);
 			if (wret < 0 && wret != -ENOSPC)
 				ret = wret;

fs/btrfs/ctree.h

@@ -45,6 +45,13 @@ struct btrfs_ordered_sum;
 
 #define BTRFS_MAX_LEVEL 8
 
+/*
+ * files bigger than this get some pre-flushing when they are added
+ * to the ordered operations list.  That way we limit the total
+ * work done by the commit
+ */
+#define BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT (8 * 1024 * 1024)
+
 /* holds pointers to all of the tree roots */
 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
 
@@ -401,15 +408,16 @@ struct btrfs_path {
 	int locks[BTRFS_MAX_LEVEL];
 	int reada;
 	/* keep some upper locks as we walk down */
-	int keep_locks;
-	int skip_locking;
 	int lowest_level;
 
 	/*
 	 * set by btrfs_split_item, tells search_slot to keep all locks
 	 * and to force calls to keep space in the nodes
 	 */
-	int search_for_split;
+	unsigned int search_for_split:1;
+	unsigned int keep_locks:1;
+	unsigned int skip_locking:1;
+	unsigned int leave_spinning:1;
 };
 
 /*
@@ -688,15 +696,18 @@ struct btrfs_fs_info {
 	struct rb_root block_group_cache_tree;
 
 	struct extent_io_tree pinned_extents;
-	struct extent_io_tree pending_del;
-	struct extent_io_tree extent_ins;
 
 	/* logical->physical extent mapping */
 	struct btrfs_mapping_tree mapping_tree;
 
 	u64 generation;
 	u64 last_trans_committed;
-	u64 last_trans_new_blockgroup;
+
+	/*
+	 * this is updated to the current trans every time a full commit
+	 * is required instead of the faster short fsync log commits
+	 */
+	u64 last_trans_log_full_commit;
 	u64 open_ioctl_trans;
 	unsigned long mount_opt;
 	u64 max_extent;
@@ -717,12 +728,21 @@ struct btrfs_fs_info {
 	struct mutex tree_log_mutex;
 	struct mutex transaction_kthread_mutex;
 	struct mutex cleaner_mutex;
-	struct mutex extent_ins_mutex;
 	struct mutex pinned_mutex;
 	struct mutex chunk_mutex;
 	struct mutex drop_mutex;
 	struct mutex volume_mutex;
 	struct mutex tree_reloc_mutex;
+
+	/*
+	 * this protects the ordered operations list only while we are
+	 * processing all of the entries on it.  This way we make
+	 * sure the commit code doesn't find the list temporarily empty
+	 * because another function happens to be doing non-waiting preflush
+	 * before jumping into the main commit.
+	 */
+	struct mutex ordered_operations_mutex;
+
 	struct list_head trans_list;
 	struct list_head hashers;
 	struct list_head dead_roots;
@@ -737,9 +757,28 @@ struct btrfs_fs_info {
 	 * ordered extents
 	 */
 	spinlock_t ordered_extent_lock;
+
+	/*
+	 * all of the data=ordered extents pending writeback
+	 * these can span multiple transactions and basically include
+	 * every dirty data page that isn't from nodatacow
+	 */
 	struct list_head ordered_extents;
+
+	/*
+	 * all of the inodes that have delalloc bytes.  It is possible for
+	 * this list to be empty even when there is still dirty data=ordered
+	 * extents waiting to finish IO.
+	 */
 	struct list_head delalloc_inodes;
 
+	/*
+	 * special rename and truncate targets that must be on disk before
+	 * we're allowed to commit.  This is basically the ext3 style
+	 * data=ordered list.
+	 */
+	struct list_head ordered_operations;
+
 	/*
 	 * there is a pool of worker threads for checksumming during writes
 	 * and a pool for checksumming after reads.  This is because readers
@@ -781,6 +820,11 @@ struct btrfs_fs_info {
 	atomic_t throttle_gen;
 
 	u64 total_pinned;
+
+	/* protected by the delalloc lock, used to keep from writing
+	 * metadata until there is a nice batch
+	 */
+	u64 dirty_metadata_bytes;
 	struct list_head dirty_cowonly_roots;
 
 	struct btrfs_fs_devices *fs_devices;
@@ -1704,18 +1748,15 @@ static inline struct dentry *fdentry(struct file *file)
 }
 
 /* extent-tree.c */
+int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, unsigned long count);
 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len);
-int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, u64 bytenr,
-			    u64 num_bytes, u32 *refs);
 int btrfs_update_pinned_extents(struct btrfs_root *root,
 				u64 bytenr, u64 num, int pin);
 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
 			struct btrfs_root *root, struct extent_buffer *leaf);
 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, u64 objectid, u64 bytenr);
-int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root);
 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy);
 struct btrfs_block_group_cache *btrfs_lookup_block_group(
 						 struct btrfs_fs_info *info,
@@ -1777,7 +1818,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 			 u64 root_objectid, u64 ref_generation,
 			 u64 owner_objectid);
 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, u64 bytenr,
+			    struct btrfs_root *root, u64 bytenr, u64 num_bytes,
 			    u64 orig_parent, u64 parent,
 			    u64 root_objectid, u64 ref_generation,
 			    u64 owner_objectid);
@@ -1838,7 +1879,7 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
 int btrfs_cow_block(struct btrfs_trans_handle *trans,
 		    struct btrfs_root *root, struct extent_buffer *buf,
 		    struct extent_buffer *parent, int parent_slot,
-		    struct extent_buffer **cow_ret, u64 prealloc_dest);
+		    struct extent_buffer **cow_ret);
 int btrfs_copy_root(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *root,
 		      struct extent_buffer *buf,

fs/btrfs/delayed-ref.c

@@ -0,0 +1,669 @@
+/*
+ * Copyright (C) 2009 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/sched.h>
+#include <linux/sort.h>
+#include <linux/ftrace.h>
+#include "ctree.h"
+#include "delayed-ref.h"
+#include "transaction.h"
+
+/*
+ * delayed back reference update tracking.  For subvolume trees
+ * we queue up extent allocations and backref maintenance for
+ * delayed processing.   This avoids deep call chains where we
+ * add extents in the middle of btrfs_search_slot, and it allows
+ * us to buffer up frequently modified backrefs in an rb tree instead
+ * of hammering updates on the extent allocation tree.
+ *
+ * Right now this code is only used for reference counted trees, but
+ * the long term goal is to get rid of the similar code for delayed
+ * extent tree modifications.
+ */
+
+/*
+ * entries in the rb tree are ordered by the byte number of the extent
+ * and by the byte number of the parent block.
+ */
+static int comp_entry(struct btrfs_delayed_ref_node *ref,
+		      u64 bytenr, u64 parent)
+{
+	if (bytenr < ref->bytenr)
+		return -1;
+	if (bytenr > ref->bytenr)
+		return 1;
+	if (parent < ref->parent)
+		return -1;
+	if (parent > ref->parent)
+		return 1;
+	return 0;
+}
+
+/*
+ * insert a new ref into the rbtree.  This returns any existing refs
+ * for the same (bytenr,parent) tuple, or NULL if the new node was properly
+ * inserted.
+ */
+static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
+						  u64 bytenr, u64 parent,
+						  struct rb_node *node)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent_node = NULL;
+	struct btrfs_delayed_ref_node *entry;
+	int cmp;
+
+	while (*p) {
+		parent_node = *p;
+		entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
+				 rb_node);
+
+		cmp = comp_entry(entry, bytenr, parent);
+		if (cmp < 0)
+			p = &(*p)->rb_left;
+		else if (cmp > 0)
+			p = &(*p)->rb_right;
+		else
+			return entry;
+	}
+
+	entry = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
+	rb_link_node(node, parent_node, p);
+	rb_insert_color(node, root);
+	return NULL;
+}
+
+/*
+ * find an entry based on (bytenr,parent).  This returns the delayed
+ * ref if it was able to find one, or NULL if nothing was in that spot
+ */
+static struct btrfs_delayed_ref_node *tree_search(struct rb_root *root,
+				  u64 bytenr, u64 parent,
+				  struct btrfs_delayed_ref_node **last)
+{
+	struct rb_node *n = root->rb_node;
+	struct btrfs_delayed_ref_node *entry;
+	int cmp;
+
+	while (n) {
+		entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
+		WARN_ON(!entry->in_tree);
+		if (last)
+			*last = entry;
+
+		cmp = comp_entry(entry, bytenr, parent);
+		if (cmp < 0)
+			n = n->rb_left;
+		else if (cmp > 0)
+			n = n->rb_right;
+		else
+			return entry;
+	}
+	return NULL;
+}
+
+int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+			   struct btrfs_delayed_ref_head *head)
+{
+	struct btrfs_delayed_ref_root *delayed_refs;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	assert_spin_locked(&delayed_refs->lock);
+	if (mutex_trylock(&head->mutex))
+		return 0;
+
+	atomic_inc(&head->node.refs);
+	spin_unlock(&delayed_refs->lock);
+
+	mutex_lock(&head->mutex);
+	spin_lock(&delayed_refs->lock);
+	if (!head->node.in_tree) {
+		mutex_unlock(&head->mutex);
+		btrfs_put_delayed_ref(&head->node);
+		return -EAGAIN;
+	}
+	btrfs_put_delayed_ref(&head->node);
+	return 0;
+}
+
+int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
+			   struct list_head *cluster, u64 start)
+{
+	int count = 0;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	struct rb_node *node;
+	struct btrfs_delayed_ref_node *ref;
+	struct btrfs_delayed_ref_head *head;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	if (start == 0) {
+		node = rb_first(&delayed_refs->root);
+	} else {
+		ref = NULL;
+		tree_search(&delayed_refs->root, start, (u64)-1, &ref);
+		if (ref) {
+			struct btrfs_delayed_ref_node *tmp;
+
+			node = rb_prev(&ref->rb_node);
+			while (node) {
+				tmp = rb_entry(node,
+					       struct btrfs_delayed_ref_node,
+					       rb_node);
+				if (tmp->bytenr < start)
+					break;
+				ref = tmp;
+				node = rb_prev(&ref->rb_node);
+			}
+			node = &ref->rb_node;
+		} else
+			node = rb_first(&delayed_refs->root);
+	}
+again:
+	while (node && count < 32) {
+		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
+		if (btrfs_delayed_ref_is_head(ref)) {
+			head = btrfs_delayed_node_to_head(ref);
+			if (list_empty(&head->cluster)) {
+				list_add_tail(&head->cluster, cluster);
+				delayed_refs->run_delayed_start =
+					head->node.bytenr;
+				count++;
+
+				WARN_ON(delayed_refs->num_heads_ready == 0);
+				delayed_refs->num_heads_ready--;
+			} else if (count) {
+				/* the goal of the clustering is to find extents
+				 * that are likely to end up in the same extent
+				 * leaf on disk.  So, we don't want them spread
+				 * all over the tree.  Stop now if we've hit
+				 * a head that was already in use
+				 */
+				break;
+			}
+		}
+		node = rb_next(node);
+	}
+	if (count) {
+		return 0;
+	} else if (start) {
+		/*
+		 * we've gone to the end of the rbtree without finding any
+		 * clusters.  start from the beginning and try again
+		 */
+		start = 0;
+		node = rb_first(&delayed_refs->root);
+		goto again;
+	}
+	return 1;
+}
+
+/*
+ * This checks to see if there are any delayed refs in the
+ * btree for a given bytenr.  It returns one if it finds any
+ * and zero otherwise.
+ *
+ * If it only finds a head node, it returns 0.
+ *
+ * The idea is to use this when deciding if you can safely delete an
+ * extent from the extent allocation tree.  There may be a pending
+ * ref in the rbtree that adds or removes references, so as long as this
+ * returns one you need to leave the BTRFS_EXTENT_ITEM in the extent
+ * allocation tree.
+ */
+int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr)
+{
+	struct btrfs_delayed_ref_node *ref;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	struct rb_node *prev_node;
+	int ret = 0;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	spin_lock(&delayed_refs->lock);
+
+	ref = tree_search(&delayed_refs->root, bytenr, (u64)-1, NULL);
+	if (ref) {
+		prev_node = rb_prev(&ref->rb_node);
+		if (!prev_node)
+			goto out;
+		ref = rb_entry(prev_node, struct btrfs_delayed_ref_node,
+			       rb_node);
+		if (ref->bytenr == bytenr)
+			ret = 1;
+	}
+out:
+	spin_unlock(&delayed_refs->lock);
+	return ret;
+}
+
+/*
+ * helper function to lookup reference count
+ *
+ * the head node for delayed ref is used to store the sum of all the
+ * reference count modifications queued up in the rbtree.  This way you
+ * can check to see what the reference count would be if all of the
+ * delayed refs are processed.
+ */
+int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, u64 bytenr,
+			    u64 num_bytes, u32 *refs)
+{
+	struct btrfs_delayed_ref_node *ref;
+	struct btrfs_delayed_ref_head *head;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_extent_item *ei;
+	struct btrfs_key key;
+	u32 num_refs;
+	int ret;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = bytenr;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = num_bytes;
+	delayed_refs = &trans->transaction->delayed_refs;
+again:
+	ret = btrfs_search_slot(trans, root->fs_info->extent_root,
+				&key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	if (ret == 0) {
+		leaf = path->nodes[0];
+		ei = btrfs_item_ptr(leaf, path->slots[0],
+				    struct btrfs_extent_item);
+		num_refs = btrfs_extent_refs(leaf, ei);
+	} else {
+		num_refs = 0;
+		ret = 0;
+	}
+
+	spin_lock(&delayed_refs->lock);
+	ref = tree_search(&delayed_refs->root, bytenr, (u64)-1, NULL);
+	if (ref) {
+		head = btrfs_delayed_node_to_head(ref);
+		if (mutex_trylock(&head->mutex)) {
+			num_refs += ref->ref_mod;
+			mutex_unlock(&head->mutex);
+			*refs = num_refs;
+			goto out;
+		}
+
+		atomic_inc(&ref->refs);
+		spin_unlock(&delayed_refs->lock);
+
+		btrfs_release_path(root->fs_info->extent_root, path);
+
+		mutex_lock(&head->mutex);
+		mutex_unlock(&head->mutex);
+		btrfs_put_delayed_ref(ref);
+		goto again;
+	} else {
+		*refs = num_refs;
+	}
+out:
+	spin_unlock(&delayed_refs->lock);
+	btrfs_free_path(path);
+	return ret;
+}
+
+/*
+ * helper function to update an extent delayed ref in the
+ * rbtree.  existing and update must both have the same
+ * bytenr and parent
+ *
+ * This may free existing if the update cancels out whatever
+ * operation it was doing.
+ */
+static noinline void
+update_existing_ref(struct btrfs_trans_handle *trans,
+		    struct btrfs_delayed_ref_root *delayed_refs,
+		    struct btrfs_delayed_ref_node *existing,
+		    struct btrfs_delayed_ref_node *update)
+{
+	struct btrfs_delayed_ref *existing_ref;
+	struct btrfs_delayed_ref *ref;
+
+	existing_ref = btrfs_delayed_node_to_ref(existing);
+	ref = btrfs_delayed_node_to_ref(update);
+
+	if (ref->pin)
+		existing_ref->pin = 1;
+
+	if (ref->action != existing_ref->action) {
+		/*
+		 * this is effectively undoing either an add or a
+		 * drop.  We decrement the ref_mod, and if it goes
+		 * down to zero we just delete the entry without
+		 * every changing the extent allocation tree.
+		 */
+		existing->ref_mod--;
+		if (existing->ref_mod == 0) {
+			rb_erase(&existing->rb_node,
+				 &delayed_refs->root);
+			existing->in_tree = 0;
+			btrfs_put_delayed_ref(existing);
+			delayed_refs->num_entries--;
+			if (trans->delayed_ref_updates)
+				trans->delayed_ref_updates--;
+		}
+	} else {
+		if (existing_ref->action == BTRFS_ADD_DELAYED_REF) {
+			/* if we're adding refs, make sure all the
+			 * details match up.  The extent could
+			 * have been totally freed and reallocated
+			 * by a different owner before the delayed
+			 * ref entries were removed.
+			 */
+			existing_ref->owner_objectid = ref->owner_objectid;
+			existing_ref->generation = ref->generation;
+			existing_ref->root = ref->root;
+			existing->num_bytes = update->num_bytes;
+		}
+		/*
+		 * the action on the existing ref matches
+		 * the action on the ref we're trying to add.
+		 * Bump the ref_mod by one so the backref that
+		 * is eventually added/removed has the correct
+		 * reference count
+		 */
+		existing->ref_mod += update->ref_mod;
+	}
+}
+
+/*
+ * helper function to update the accounting in the head ref
+ * existing and update must have the same bytenr
+ */
+static noinline void
+update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
+			 struct btrfs_delayed_ref_node *update)
+{
+	struct btrfs_delayed_ref_head *existing_ref;
+	struct btrfs_delayed_ref_head *ref;
+
+	existing_ref = btrfs_delayed_node_to_head(existing);
+	ref = btrfs_delayed_node_to_head(update);
+
+	if (ref->must_insert_reserved) {
+		/* if the extent was freed and then
+		 * reallocated before the delayed ref
+		 * entries were processed, we can end up
+		 * with an existing head ref without
+		 * the must_insert_reserved flag set.
+		 * Set it again here
+		 */
+		existing_ref->must_insert_reserved = ref->must_insert_reserved;
+
+		/*
+		 * update the num_bytes so we make sure the accounting
+		 * is done correctly
+		 */
+		existing->num_bytes = update->num_bytes;
+
+	}
+
+	/*
+	 * update the reference mod on the head to reflect this new operation
+	 */
+	existing->ref_mod += update->ref_mod;
+}
+
+/*
+ * helper function to actually insert a delayed ref into the rbtree.
+ * this does all the dirty work in terms of maintaining the correct
+ * overall modification count in the head node and properly dealing
+ * with updating existing nodes as new modifications are queued.
+ */
+static noinline int __btrfs_add_delayed_ref(struct btrfs_trans_handle *trans,
+			  struct btrfs_delayed_ref_node *ref,
+			  u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root,
+			  u64 ref_generation, u64 owner_objectid, int action,
+			  int pin)
+{
+	struct btrfs_delayed_ref_node *existing;
+	struct btrfs_delayed_ref *full_ref;
+	struct btrfs_delayed_ref_head *head_ref = NULL;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	int count_mod = 1;
+	int must_insert_reserved = 0;
+
+	/*
+	 * the head node stores the sum of all the mods, so dropping a ref
+	 * should drop the sum in the head node by one.
+	 */
+	if (parent == (u64)-1) {
+		if (action == BTRFS_DROP_DELAYED_REF)
+			count_mod = -1;
+		else if (action == BTRFS_UPDATE_DELAYED_HEAD)
+			count_mod = 0;
+	}
+
+	/*
+	 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
+	 * the reserved accounting when the extent is finally added, or
+	 * if a later modification deletes the delayed ref without ever
+	 * inserting the extent into the extent allocation tree.
+	 * ref->must_insert_reserved is the flag used to record
+	 * that accounting mods are required.
+	 *
+	 * Once we record must_insert_reserved, switch the action to
+	 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
+	 */
+	if (action == BTRFS_ADD_DELAYED_EXTENT) {
+		must_insert_reserved = 1;
+		action = BTRFS_ADD_DELAYED_REF;
+	} else {
+		must_insert_reserved = 0;
+	}
+
+
+	delayed_refs = &trans->transaction->delayed_refs;
+
+	/* first set the basic ref node struct up */
+	atomic_set(&ref->refs, 1);
+	ref->bytenr = bytenr;
+	ref->parent = parent;
+	ref->ref_mod = count_mod;
+	ref->in_tree = 1;
+	ref->num_bytes = num_bytes;
+
+	if (btrfs_delayed_ref_is_head(ref)) {
+		head_ref = btrfs_delayed_node_to_head(ref);
+		head_ref->must_insert_reserved = must_insert_reserved;
+		INIT_LIST_HEAD(&head_ref->cluster);
+		mutex_init(&head_ref->mutex);
+	} else {
+		full_ref = btrfs_delayed_node_to_ref(ref);
+		full_ref->root = ref_root;
+		full_ref->generation = ref_generation;
+		full_ref->owner_objectid = owner_objectid;
+		full_ref->pin = pin;
+		full_ref->action = action;
+	}
+
+	existing = tree_insert(&delayed_refs->root, bytenr,
+			       parent, &ref->rb_node);
+
+	if (existing) {
+		if (btrfs_delayed_ref_is_head(ref))
+			update_existing_head_ref(existing, ref);
+		else
+			update_existing_ref(trans, delayed_refs, existing, ref);
+
+		/*
+		 * we've updated the existing ref, free the newly
+		 * allocated ref
+		 */
+		kfree(ref);
+	} else {
+		if (btrfs_delayed_ref_is_head(ref)) {
+			delayed_refs->num_heads++;
+			delayed_refs->num_heads_ready++;
+		}
+		delayed_refs->num_entries++;
+		trans->delayed_ref_updates++;
+	}
+	return 0;
+}
+
+/*
+ * add a delayed ref to the tree.  This does all of the accounting required
+ * to make sure the delayed ref is eventually processed before this
+ * transaction commits.
+ */
+int btrfs_add_delayed_ref(struct btrfs_trans_handle *trans,
+			  u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root,
+			  u64 ref_generation, u64 owner_objectid, int action,
+			  int pin)
+{
+	struct btrfs_delayed_ref *ref;
+	struct btrfs_delayed_ref_head *head_ref;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	int ret;
+
+	ref = kmalloc(sizeof(*ref), GFP_NOFS);
+	if (!ref)
+		return -ENOMEM;
+
+	/*
+	 * the parent = 0 case comes from cases where we don't actually
+	 * know the parent yet.  It will get updated later via a add/drop
+	 * pair.
+	 */
+	if (parent == 0)
+		parent = bytenr;
+
+	head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
+	if (!head_ref) {
+		kfree(ref);
+		return -ENOMEM;
+	}
+	delayed_refs = &trans->transaction->delayed_refs;
+	spin_lock(&delayed_refs->lock);
+
+	/*
+	 * insert both the head node and the new ref without dropping
+	 * the spin lock
+	 */
+	ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes,
+				      (u64)-1, 0, 0, 0, action, pin);
+	BUG_ON(ret);
+
+	ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes,
+				      parent, ref_root, ref_generation,
+				      owner_objectid, action, pin);
+	BUG_ON(ret);
+	spin_unlock(&delayed_refs->lock);
+	return 0;
+}
+
+/*
+ * this does a simple search for the head node for a given extent.
+ * It must be called with the delayed ref spinlock held, and it returns
+ * the head node if any where found, or NULL if not.
+ */
+struct btrfs_delayed_ref_head *
+btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
+{
+	struct btrfs_delayed_ref_node *ref;
+	struct btrfs_delayed_ref_root *delayed_refs;
+
+	delayed_refs = &trans->transaction->delayed_refs;
+	ref = tree_search(&delayed_refs->root, bytenr, (u64)-1, NULL);
+	if (ref)
+		return btrfs_delayed_node_to_head(ref);
+	return NULL;
+}
+
+/*
+ * add a delayed ref to the tree.  This does all of the accounting required
+ * to make sure the delayed ref is eventually processed before this
+ * transaction commits.
+ *
+ * The main point of this call is to add and remove a backreference in a single
+ * shot, taking the lock only once, and only searching for the head node once.
+ *
+ * It is the same as doing a ref add and delete in two separate calls.
+ */
+int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans,
+			  u64 bytenr, u64 num_bytes, u64 orig_parent,
+			  u64 parent, u64 orig_ref_root, u64 ref_root,
+			  u64 orig_ref_generation, u64 ref_generation,
+			  u64 owner_objectid, int pin)
+{
+	struct btrfs_delayed_ref *ref;
+	struct btrfs_delayed_ref *old_ref;
+	struct btrfs_delayed_ref_head *head_ref;
+	struct btrfs_delayed_ref_root *delayed_refs;
+	int ret;
+
+	ref = kmalloc(sizeof(*ref), GFP_NOFS);
+	if (!ref)
+		return -ENOMEM;
+
+	old_ref = kmalloc(sizeof(*old_ref), GFP_NOFS);
+	if (!old_ref) {
+		kfree(ref);
+		return -ENOMEM;
+	}
+
+	/*
+	 * the parent = 0 case comes from cases where we don't actually
+	 * know the parent yet.  It will get updated later via a add/drop
+	 * pair.
+	 */
+	if (parent == 0)
+		parent = bytenr;
+	if (orig_parent == 0)
+		orig_parent = bytenr;
+
+	head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
+	if (!head_ref) {
+		kfree(ref);
+		kfree(old_ref);
+		return -ENOMEM;
+	}
+	delayed_refs = &trans->transaction->delayed_refs;
+	spin_lock(&delayed_refs->lock);
+
+	/*
+	 * insert both the head node and the new ref without dropping
+	 * the spin lock
+	 */
+	ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes,
+				      (u64)-1, 0, 0, 0,
+				      BTRFS_UPDATE_DELAYED_HEAD, 0);
+	BUG_ON(ret);
+
+	ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes,
+				      parent, ref_root, ref_generation,
+				      owner_objectid, BTRFS_ADD_DELAYED_REF, 0);
+	BUG_ON(ret);
+
+	ret = __btrfs_add_delayed_ref(trans, &old_ref->node, bytenr, num_bytes,
+				      orig_parent, orig_ref_root,
+				      orig_ref_generation, owner_objectid,
+				      BTRFS_DROP_DELAYED_REF, pin);
+	BUG_ON(ret);
+	spin_unlock(&delayed_refs->lock);
+	return 0;
+}

fs/btrfs/delayed-ref.h

@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#ifndef __DELAYED_REF__
+#define __DELAYED_REF__
+
+/* these are the possible values of struct btrfs_delayed_ref->action */
+#define BTRFS_ADD_DELAYED_REF    1 /* add one backref to the tree */
+#define BTRFS_DROP_DELAYED_REF   2 /* delete one backref from the tree */
+#define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
+#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
+
+struct btrfs_delayed_ref_node {
+	struct rb_node rb_node;
+
+	/* the starting bytenr of the extent */
+	u64 bytenr;
+
+	/* the parent our backref will point to */
+	u64 parent;
+
+	/* the size of the extent */
+	u64 num_bytes;
+
+	/* ref count on this data structure */
+	atomic_t refs;
+
+	/*
+	 * how many refs is this entry adding or deleting.  For
+	 * head refs, this may be a negative number because it is keeping
+	 * track of the total mods done to the reference count.
+	 * For individual refs, this will always be a positive number
+	 *
+	 * It may be more than one, since it is possible for a single
+	 * parent to have more than one ref on an extent
+	 */
+	int ref_mod;
+
+	/* is this node still in the rbtree? */
+	unsigned int in_tree:1;
+};
+
+/*
+ * the head refs are used to hold a lock on a given extent, which allows us
+ * to make sure that only one process is running the delayed refs
+ * at a time for a single extent.  They also store the sum of all the
+ * reference count modifications we've queued up.
+ */
+struct btrfs_delayed_ref_head {
+	struct btrfs_delayed_ref_node node;
+
+	/*
+	 * the mutex is held while running the refs, and it is also
+	 * held when checking the sum of reference modifications.
+	 */
+	struct mutex mutex;
+
+	struct list_head cluster;
+
+	/*
+	 * when a new extent is allocated, it is just reserved in memory
+	 * The actual extent isn't inserted into the extent allocation tree
+	 * until the delayed ref is processed.  must_insert_reserved is
+	 * used to flag a delayed ref so the accounting can be updated
+	 * when a full insert is done.
+	 *
+	 * It is possible the extent will be freed before it is ever
+	 * inserted into the extent allocation tree.  In this case
+	 * we need to update the in ram accounting to properly reflect
+	 * the free has happened.
+	 */
+	unsigned int must_insert_reserved:1;
+};
+
+struct btrfs_delayed_ref {
+	struct btrfs_delayed_ref_node node;
+
+	/* the root objectid our ref will point to */
+	u64 root;
+
+	/* the generation for the backref */
+	u64 generation;
+
+	/* owner_objectid of the backref  */
+	u64 owner_objectid;
+
+	/* operation done by this entry in the rbtree */
+	u8 action;
+
+	/* if pin == 1, when the extent is freed it will be pinned until
+	 * transaction commit
+	 */
+	unsigned int pin:1;
+};
+
+struct btrfs_delayed_ref_root {
+	struct rb_root root;
+
+	/* this spin lock protects the rbtree and the entries inside */
+	spinlock_t lock;
+
+	/* how many delayed ref updates we've queued, used by the
+	 * throttling code
+	 */
+	unsigned long num_entries;
+
+	/* total number of head nodes in tree */
+	unsigned long num_heads;
+
+	/* total number of head nodes ready for processing */
+	unsigned long num_heads_ready;
+
+	/*
+	 * set when the tree is flushing before a transaction commit,
+	 * used by the throttling code to decide if new updates need
+	 * to be run right away
+	 */
+	int flushing;
+
+	u64 run_delayed_start;
+};
+
+static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
+{
+	WARN_ON(atomic_read(&ref->refs) == 0);
+	if (atomic_dec_and_test(&ref->refs)) {
+		WARN_ON(ref->in_tree);
+		kfree(ref);
+	}
+}
+
+int btrfs_add_delayed_ref(struct btrfs_trans_handle *trans,
+			  u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root,
+			  u64 ref_generation, u64 owner_objectid, int action,
+			  int pin);
+
+struct btrfs_delayed_ref_head *
+btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
+int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr);
+int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, u64 bytenr,
+			    u64 num_bytes, u32 *refs);
+int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans,
+			  u64 bytenr, u64 num_bytes, u64 orig_parent,
+			  u64 parent, u64 orig_ref_root, u64 ref_root,
+			  u64 orig_ref_generation, u64 ref_generation,
+			  u64 owner_objectid, int pin);
+int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
+			   struct btrfs_delayed_ref_head *head);
+int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
+			   struct list_head *cluster, u64 search_start);
+/*
+ * a node might live in a head or a regular ref, this lets you
+ * test for the proper type to use.
+ */
+static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
+{
+	return node->parent == (u64)-1;
+}
+
+/*
+ * helper functions to cast a node into its container
+ */
+static inline struct btrfs_delayed_ref *
+btrfs_delayed_node_to_ref(struct btrfs_delayed_ref_node *node)
+{
+	WARN_ON(btrfs_delayed_ref_is_head(node));
+	return container_of(node, struct btrfs_delayed_ref, node);
+
+}
+
+static inline struct btrfs_delayed_ref_head *
+btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
+{
+	WARN_ON(!btrfs_delayed_ref_is_head(node));
+	return container_of(node, struct btrfs_delayed_ref_head, node);
+
+}
+#endif

fs/btrfs/dir-item.c

@@ -145,7 +145,10 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	key.objectid = dir;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
+
 	path = btrfs_alloc_path();
+	path->leave_spinning = 1;
+
 	data_size = sizeof(*dir_item) + name_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 					name, name_len);

fs/btrfs/disk-io.c

@@ -668,14 +668,31 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 {
 	struct extent_io_tree *tree;
+	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+	struct extent_buffer *eb;
+	int was_dirty;
+
 	tree = &BTRFS_I(page->mapping->host)->io_tree;
+	if (!(current->flags & PF_MEMALLOC)) {
+		return extent_write_full_page(tree, page,
+					      btree_get_extent, wbc);
+	}
 
-	if (current->flags & PF_MEMALLOC) {
-		redirty_page_for_writepage(wbc, page);
-		unlock_page(page);
-		return 0;
+	redirty_page_for_writepage(wbc, page);
+	eb = btrfs_find_tree_block(root, page_offset(page),
+				      PAGE_CACHE_SIZE);
+	WARN_ON(!eb);
+
+	was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
+	if (!was_dirty) {
+		spin_lock(&root->fs_info->delalloc_lock);
+		root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
+		spin_unlock(&root->fs_info->delalloc_lock);
 	}
-	return extent_write_full_page(tree, page, btree_get_extent, wbc);
+	free_extent_buffer(eb);
+
+	unlock_page(page);
+	return 0;
 }
 
 static int btree_writepages(struct address_space *mapping,
@@ -684,15 +701,15 @@ static int btree_writepages(struct address_space *mapping,
 	struct extent_io_tree *tree;
 	tree = &BTRFS_I(mapping->host)->io_tree;
 	if (wbc->sync_mode == WB_SYNC_NONE) {
+		struct btrfs_root *root = BTRFS_I(mapping->host)->root;
 		u64 num_dirty;
-		u64 start = 0;
 		unsigned long thresh = 32 * 1024 * 1024;
 
 		if (wbc->for_kupdate)
 			return 0;
 
-		num_dirty = count_range_bits(tree, &start, (u64)-1,
-					     thresh, EXTENT_DIRTY);
+		/* this is a bit racy, but that's ok */
+		num_dirty = root->fs_info->dirty_metadata_bytes;
 		if (num_dirty < thresh)
 			return 0;
 	}
@@ -859,9 +876,17 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	    root->fs_info->running_transaction->transid) {
 		btrfs_assert_tree_locked(buf);
 
-		/* ugh, clear_extent_buffer_dirty can be expensive */
-		btrfs_set_lock_blocking(buf);
+		if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
+			spin_lock(&root->fs_info->delalloc_lock);
+			if (root->fs_info->dirty_metadata_bytes >= buf->len)
+				root->fs_info->dirty_metadata_bytes -= buf->len;
+			else
+				WARN_ON(1);
+			spin_unlock(&root->fs_info->delalloc_lock);
+		}
 
+		/* ugh, clear_extent_buffer_dirty needs to lock the page */
+		btrfs_set_lock_blocking(buf);
 		clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 					  buf);
 	}
@@ -1471,12 +1496,6 @@ static int transaction_kthread(void *arg)
 		vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
 		mutex_lock(&root->fs_info->transaction_kthread_mutex);
 
-		if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
-			printk(KERN_INFO "btrfs: total reference cache "
-			       "size %llu\n",
-			       root->fs_info->total_ref_cache_size);
-		}
-
 		mutex_lock(&root->fs_info->trans_mutex);
 		cur = root->fs_info->running_transaction;
 		if (!cur) {
@@ -1493,6 +1512,7 @@ static int transaction_kthread(void *arg)
 		mutex_unlock(&root->fs_info->trans_mutex);
 		trans = btrfs_start_transaction(root, 1);
 		ret = btrfs_commit_transaction(trans, root);
+
 sleep:
 		wake_up_process(root->fs_info->cleaner_kthread);
 		mutex_unlock(&root->fs_info->transaction_kthread_mutex);
@@ -1552,6 +1572,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	INIT_LIST_HEAD(&fs_info->dead_roots);
 	INIT_LIST_HEAD(&fs_info->hashers);
 	INIT_LIST_HEAD(&fs_info->delalloc_inodes);
+	INIT_LIST_HEAD(&fs_info->ordered_operations);
 	spin_lock_init(&fs_info->delalloc_lock);
 	spin_lock_init(&fs_info->new_trans_lock);
 	spin_lock_init(&fs_info->ref_cache_lock);
@@ -1611,10 +1632,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	extent_io_tree_init(&fs_info->pinned_extents,
 			     fs_info->btree_inode->i_mapping, GFP_NOFS);
-	extent_io_tree_init(&fs_info->pending_del,
-			     fs_info->btree_inode->i_mapping, GFP_NOFS);
-	extent_io_tree_init(&fs_info->extent_ins,
-			     fs_info->btree_inode->i_mapping, GFP_NOFS);
 	fs_info->do_barriers = 1;
 
 	INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
@@ -1627,9 +1644,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	insert_inode_hash(fs_info->btree_inode);
 
 	mutex_init(&fs_info->trans_mutex);
+	mutex_init(&fs_info->ordered_operations_mutex);
 	mutex_init(&fs_info->tree_log_mutex);
 	mutex_init(&fs_info->drop_mutex);
-	mutex_init(&fs_info->extent_ins_mutex);
 	mutex_init(&fs_info->pinned_mutex);
 	mutex_init(&fs_info->chunk_mutex);
 	mutex_init(&fs_info->transaction_kthread_mutex);
@@ -2358,8 +2375,7 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 	u64 transid = btrfs_header_generation(buf);
 	struct inode *btree_inode = root->fs_info->btree_inode;
-
-	btrfs_set_lock_blocking(buf);
+	int was_dirty;
 
 	btrfs_assert_tree_locked(buf);
 	if (transid != root->fs_info->generation) {
@@ -2370,7 +2386,13 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 			(unsigned long long)root->fs_info->generation);
 		WARN_ON(1);
 	}
-	set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
+	was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
+					    buf);
+	if (!was_dirty) {
+		spin_lock(&root->fs_info->delalloc_lock);
+		root->fs_info->dirty_metadata_bytes += buf->len;
+		spin_unlock(&root->fs_info->delalloc_lock);
+	}
 }
 
 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
@@ -2410,6 +2432,7 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
 int btree_lock_page_hook(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	struct extent_buffer *eb;
 	unsigned long len;
@@ -2425,6 +2448,16 @@ int btree_lock_page_hook(struct page *page)
 
 	btrfs_tree_lock(eb);
 	btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
+
+	if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
+		spin_lock(&root->fs_info->delalloc_lock);
+		if (root->fs_info->dirty_metadata_bytes >= eb->len)
+			root->fs_info->dirty_metadata_bytes -= eb->len;
+		else
+			WARN_ON(1);
+		spin_unlock(&root->fs_info->delalloc_lock);
+	}
+
 	btrfs_tree_unlock(eb);
 	free_extent_buffer(eb);
 out:

fs/btrfs/disk-io.h

@@ -72,6 +72,7 @@ int btrfs_insert_dev_radix(struct btrfs_root *root,
 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
+void btrfs_mark_buffer_dirty_nonblocking(struct extent_buffer *buf);
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
 int wait_on_tree_block_writeback(struct btrfs_root *root,

fs/btrfs/extent_io.c

@@ -3124,20 +3124,15 @@ void free_extent_buffer(struct extent_buffer *eb)
 int clear_extent_buffer_dirty(struct extent_io_tree *tree,
 			      struct extent_buffer *eb)
 {
-	int set;
 	unsigned long i;
 	unsigned long num_pages;
 	struct page *page;
 
-	u64 start = eb->start;
-	u64 end = start + eb->len - 1;
-
-	set = clear_extent_dirty(tree, start, end, GFP_NOFS);
 	num_pages = num_extent_pages(eb->start, eb->len);
 
 	for (i = 0; i < num_pages; i++) {
 		page = extent_buffer_page(eb, i);
-		if (!set && !PageDirty(page))
+		if (!PageDirty(page))
 			continue;
 
 		lock_page(page);
@@ -3146,22 +3141,6 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree,
 		else
 			set_page_private(page, EXTENT_PAGE_PRIVATE);
 
-		/*
-		 * if we're on the last page or the first page and the
-		 * block isn't aligned on a page boundary, do extra checks
-		 * to make sure we don't clean page that is partially dirty
-		 */
-		if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
-		    ((i == num_pages - 1) &&
-		     ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
-			start = (u64)page->index << PAGE_CACHE_SHIFT;
-			end  = start + PAGE_CACHE_SIZE - 1;
-			if (test_range_bit(tree, start, end,
-					   EXTENT_DIRTY, 0)) {
-				unlock_page(page);
-				continue;
-			}
-		}
 		clear_page_dirty_for_io(page);
 		spin_lock_irq(&page->mapping->tree_lock);
 		if (!PageDirty(page)) {
@@ -3187,29 +3166,13 @@ int set_extent_buffer_dirty(struct extent_io_tree *tree,
 {
 	unsigned long i;
 	unsigned long num_pages;
+	int was_dirty = 0;
 
+	was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
 	num_pages = num_extent_pages(eb->start, eb->len);
-	for (i = 0; i < num_pages; i++) {
-		struct page *page = extent_buffer_page(eb, i);
-		/* writepage may need to do something special for the
-		 * first page, we have to make sure page->private is
-		 * properly set.  releasepage may drop page->private
-		 * on us if the page isn't already dirty.
-		 */
-		lock_page(page);
-		if (i == 0) {
-			set_page_extent_head(page, eb->len);
-		} else if (PagePrivate(page) &&
-			   page->private != EXTENT_PAGE_PRIVATE) {
-			set_page_extent_mapped(page);
-		}
+	for (i = 0; i < num_pages; i++)
 		__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
-		set_extent_dirty(tree, page_offset(page),
-				 page_offset(page) + PAGE_CACHE_SIZE - 1,
-				 GFP_NOFS);
-		unlock_page(page);
-	}
-	return 0;
+	return was_dirty;
 }
 
 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
@@ -3789,6 +3752,10 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
 		ret = 0;
 		goto out;
 	}
+	if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
+		ret = 0;
+		goto out;
+	}
 	/* at this point we can safely release the extent buffer */
 	num_pages = num_extent_pages(eb->start, eb->len);
 	for (i = 0; i < num_pages; i++)

fs/btrfs/extent_io.h

@@ -25,6 +25,7 @@
 /* these are bit numbers for test/set bit */
 #define EXTENT_BUFFER_UPTODATE 0
 #define EXTENT_BUFFER_BLOCKING 1
+#define EXTENT_BUFFER_DIRTY 2
 
 /*
  * page->private values.  Every page that is controlled by the extent
@@ -254,6 +255,8 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree,
 			      struct extent_buffer *eb);
 int set_extent_buffer_dirty(struct extent_io_tree *tree,
 			     struct extent_buffer *eb);
+int test_extent_buffer_dirty(struct extent_io_tree *tree,
+			     struct extent_buffer *eb);
 int set_extent_buffer_uptodate(struct extent_io_tree *tree,
 			       struct extent_buffer *eb);
 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,

fs/btrfs/file-item.c

@@ -52,6 +52,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 	file_key.offset = pos;
 	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 
+	path->leave_spinning = 1;
 	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 				      sizeof(*item));
 	if (ret < 0)
@@ -523,6 +524,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 		key.offset = end_byte - 1;
 		key.type = BTRFS_EXTENT_CSUM_KEY;
 
+		path->leave_spinning = 1;
 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 		if (ret > 0) {
 			if (path->slots[0] == 0)
@@ -757,8 +759,10 @@ insert:
 	} else {
 		ins_size = csum_size;
 	}
+	path->leave_spinning = 1;
 	ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 				      ins_size);
+	path->leave_spinning = 0;
 	if (ret < 0)
 		goto fail_unlock;
 	if (ret != 0) {
@@ -776,7 +780,6 @@ found:
 	item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
 				      btrfs_item_size_nr(leaf, path->slots[0]));
 	eb_token = NULL;
-	cond_resched();
 next_sector:
 
 	if (!eb_token ||
@@ -817,9 +820,9 @@ next_sector:
 		eb_token = NULL;
 	}
 	btrfs_mark_buffer_dirty(path->nodes[0]);
-	cond_resched();
 	if (total_bytes < sums->len) {
 		btrfs_release_path(root, path);
+		cond_resched();
 		goto again;
 	}
 out:

fs/btrfs/file.c

@@ -606,6 +606,7 @@ next_slot:
 			btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
 
 			btrfs_release_path(root, path);
+			path->leave_spinning = 1;
 			ret = btrfs_insert_empty_item(trans, root, path, &ins,
 						      sizeof(*extent));
 			BUG_ON(ret);
@@ -639,17 +640,22 @@ next_slot:
 							ram_bytes);
 			btrfs_set_file_extent_type(leaf, extent, found_type);
 
+			btrfs_unlock_up_safe(path, 1);
 			btrfs_mark_buffer_dirty(path->nodes[0]);
+			btrfs_set_lock_blocking(path->nodes[0]);
 
 			if (disk_bytenr != 0) {
 				ret = btrfs_update_extent_ref(trans, root,
-						disk_bytenr, orig_parent,
+						disk_bytenr,
+						le64_to_cpu(old.disk_num_bytes),
+						orig_parent,
 						leaf->start,
 						root->root_key.objectid,
 						trans->transid, ins.objectid);
 
 				BUG_ON(ret);
 			}
+			path->leave_spinning = 0;
 			btrfs_release_path(root, path);
 			if (disk_bytenr != 0)
 				inode_add_bytes(inode, extent_end - end);
@@ -912,7 +918,7 @@ again:
 	btrfs_set_file_extent_other_encoding(leaf, fi, 0);
 
 	if (orig_parent != leaf->start) {
-		ret = btrfs_update_extent_ref(trans, root, bytenr,
+		ret = btrfs_update_extent_ref(trans, root, bytenr, num_bytes,
 					      orig_parent, leaf->start,
 					      root->root_key.objectid,
 					      trans->transid, inode->i_ino);
@@ -1155,6 +1161,20 @@ out_nolock:
 		page_cache_release(pinned[1]);
 	*ppos = pos;
 
+	/*
+	 * we want to make sure fsync finds this change
+	 * but we haven't joined a transaction running right now.
+	 *
+	 * Later on, someone is sure to update the inode and get the
+	 * real transid recorded.
+	 *
+	 * We set last_trans now to the fs_info generation + 1,
+	 * this will either be one more than the running transaction
+	 * or the generation used for the next transaction if there isn't
+	 * one running right now.
+	 */
+	BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
+
 	if (num_written > 0 && will_write) {
 		struct btrfs_trans_handle *trans;
 
@@ -1167,8 +1187,11 @@ out_nolock:
 			ret = btrfs_log_dentry_safe(trans, root,
 						    file->f_dentry);
 			if (ret == 0) {
-				btrfs_sync_log(trans, root);
-				btrfs_end_transaction(trans, root);
+				ret = btrfs_sync_log(trans, root);
+				if (ret == 0)
+					btrfs_end_transaction(trans, root);
+				else
+					btrfs_commit_transaction(trans, root);
 			} else {
 				btrfs_commit_transaction(trans, root);
 			}
@@ -1185,6 +1208,18 @@ out_nolock:
 
 int btrfs_release_file(struct inode *inode, struct file *filp)
 {
+	/*
+	 * ordered_data_close is set by settattr when we are about to truncate
+	 * a file from a non-zero size to a zero size.  This tries to
+	 * flush down new bytes that may have been written if the
+	 * application were using truncate to replace a file in place.
+	 */
+	if (BTRFS_I(inode)->ordered_data_close) {
+		BTRFS_I(inode)->ordered_data_close = 0;
+		btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
+		if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+			filemap_flush(inode->i_mapping);
+	}
 	if (filp->private_data)
 		btrfs_ioctl_trans_end(filp);
 	return 0;
@@ -1260,8 +1295,11 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
 	if (ret > 0) {
 		ret = btrfs_commit_transaction(trans, root);
 	} else {
-		btrfs_sync_log(trans, root);
-		ret = btrfs_end_transaction(trans, root);
+		ret = btrfs_sync_log(trans, root);
+		if (ret == 0)
+			ret = btrfs_end_transaction(trans, root);
+		else
+			ret = btrfs_commit_transaction(trans, root);
 	}
 	mutex_lock(&dentry->d_inode->i_mutex);
 out:

fs/btrfs/inode-item.c

@@ -73,6 +73,8 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 	if (!path)
 		return -ENOMEM;
 
+	path->leave_spinning = 1;
+
 	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 	if (ret > 0) {
 		ret = -ENOENT;
@@ -127,6 +129,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	if (!path)
 		return -ENOMEM;
 
+	path->leave_spinning = 1;
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
 				      ins_len);
 	if (ret == -EEXIST) {

fs/btrfs/inode.c

@@ -134,6 +134,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
 	if (!path)
 		return -ENOMEM;
 
+	path->leave_spinning = 1;
 	btrfs_set_trans_block_group(trans, inode);
 
 	key.objectid = inode->i_ino;
@@ -167,9 +168,9 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
 			cur_size = min_t(unsigned long, compressed_size,
 				       PAGE_CACHE_SIZE);
 
-			kaddr = kmap(cpage);
+			kaddr = kmap_atomic(cpage, KM_USER0);
 			write_extent_buffer(leaf, kaddr, ptr, cur_size);
-			kunmap(cpage);
+			kunmap_atomic(kaddr, KM_USER0);
 
 			i++;
 			ptr += cur_size;
@@ -204,7 +205,7 @@ fail:
  * does the checks required to make sure the data is small enough
  * to fit as an inline extent.
  */
-static int cow_file_range_inline(struct btrfs_trans_handle *trans,
+static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 struct inode *inode, u64 start, u64 end,
 				 size_t compressed_size,
@@ -854,11 +855,6 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 	u64 cur_end;
 	int limit = 10 * 1024 * 1042;
 
-	if (!btrfs_test_opt(root, COMPRESS)) {
-		return cow_file_range(inode, locked_page, start, end,
-				      page_started, nr_written, 1);
-	}
-
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
 			 EXTENT_DELALLOC, 1, 0, GFP_NOFS);
 	while (start < end) {
@@ -935,7 +931,8 @@ static noinline int csum_exist_in_range(struct btrfs_root *root,
  * If no cow copies or snapshots exist, we write directly to the existing
  * blocks on disk
  */
-static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
+static noinline int run_delalloc_nocow(struct inode *inode,
+				       struct page *locked_page,
 			      u64 start, u64 end, int *page_started, int force,
 			      unsigned long *nr_written)
 {
@@ -1133,6 +1130,7 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
 			      unsigned long *nr_written)
 {
 	int ret;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 
 	if (btrfs_test_flag(inode, NODATACOW))
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
@@ -1140,10 +1138,12 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
 	else if (btrfs_test_flag(inode, PREALLOC))
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 0, nr_written);
+	else if (!btrfs_test_opt(root, COMPRESS))
+		ret = cow_file_range(inode, locked_page, start, end,
+				      page_started, nr_written, 1);
 	else
 		ret = cow_file_range_async(inode, locked_page, start, end,
 					   page_started, nr_written);
-
 	return ret;
 }
 
@@ -1453,6 +1453,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
 
+	path->leave_spinning = 1;
 	ret = btrfs_drop_extents(trans, root, inode, file_pos,
 				 file_pos + num_bytes, file_pos, &hint);
 	BUG_ON(ret);
@@ -1475,6 +1476,10 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	btrfs_set_file_extent_compression(leaf, fi, compression);
 	btrfs_set_file_extent_encryption(leaf, fi, encryption);
 	btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
+
+	btrfs_unlock_up_safe(path, 1);
+	btrfs_set_lock_blocking(leaf);
+
 	btrfs_mark_buffer_dirty(leaf);
 
 	inode_add_bytes(inode, num_bytes);
@@ -1487,11 +1492,35 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 					  root->root_key.objectid,
 					  trans->transid, inode->i_ino, &ins);
 	BUG_ON(ret);
-
 	btrfs_free_path(path);
+
 	return 0;
 }
 
+/*
+ * helper function for btrfs_finish_ordered_io, this
+ * just reads in some of the csum leaves to prime them into ram
+ * before we start the transaction.  It limits the amount of btree
+ * reads required while inside the transaction.
+ */
+static noinline void reada_csum(struct btrfs_root *root,
+				struct btrfs_path *path,
+				struct btrfs_ordered_extent *ordered_extent)
+{
+	struct btrfs_ordered_sum *sum;
+	u64 bytenr;
+
+	sum = list_entry(ordered_extent->list.next, struct btrfs_ordered_sum,
+			 list);
+	bytenr = sum->sums[0].bytenr;
+
+	/*
+	 * we don't care about the results, the point of this search is
+	 * just to get the btree leaves into ram
+	 */
+	btrfs_lookup_csum(NULL, root->fs_info->csum_root, path, bytenr, 0);
+}
+
 /* as ordered data IO finishes, this gets called so we can finish
  * an ordered extent if the range of bytes in the file it covers are
  * fully written.
@@ -1500,8 +1529,9 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
-	struct btrfs_ordered_extent *ordered_extent;
+	struct btrfs_ordered_extent *ordered_extent = NULL;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct btrfs_path *path;
 	int compressed = 0;
 	int ret;
 
@@ -1509,9 +1539,33 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 	if (!ret)
 		return 0;
 
+	/*
+	 * before we join the transaction, try to do some of our IO.
+	 * This will limit the amount of IO that we have to do with
+	 * the transaction running.  We're unlikely to need to do any
+	 * IO if the file extents are new, the disk_i_size checks
+	 * covers the most common case.
+	 */
+	if (start < BTRFS_I(inode)->disk_i_size) {
+		path = btrfs_alloc_path();
+		if (path) {
+			ret = btrfs_lookup_file_extent(NULL, root, path,
+						       inode->i_ino,
+						       start, 0);
+			ordered_extent = btrfs_lookup_ordered_extent(inode,
+								     start);
+			if (!list_empty(&ordered_extent->list)) {
+				btrfs_release_path(root, path);
+				reada_csum(root, path, ordered_extent);
+			}
+			btrfs_free_path(path);
+		}
+	}
+
 	trans = btrfs_join_transaction(root, 1);
 
-	ordered_extent = btrfs_lookup_ordered_extent(inode, start);
+	if (!ordered_extent)
+		ordered_extent = btrfs_lookup_ordered_extent(inode, start);
 	BUG_ON(!ordered_extent);
 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
 		goto nocow;
@@ -2101,6 +2155,7 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
 
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
+	path->leave_spinning = 1;
 	ret = btrfs_lookup_inode(trans, root, path,
 				 &BTRFS_I(inode)->location, 1);
 	if (ret) {
@@ -2147,6 +2202,7 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto err;
 	}
 
+	path->leave_spinning = 1;
 	di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
 				    name, name_len, -1);
 	if (IS_ERR(di)) {
@@ -2190,8 +2246,6 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
 					 inode, dir->i_ino);
 	BUG_ON(ret != 0 && ret != -ENOENT);
-	if (ret != -ENOENT)
-		BTRFS_I(dir)->log_dirty_trans = trans->transid;
 
 	ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
 					   dir, index);
@@ -2224,6 +2278,9 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 	trans = btrfs_start_transaction(root, 1);
 
 	btrfs_set_trans_block_group(trans, dir);
+
+	btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
+
 	ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
 				 dentry->d_name.name, dentry->d_name.len);
 
@@ -2498,6 +2555,7 @@ noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 	key.type = (u8)-1;
 
 search_again:
+	path->leave_spinning = 1;
 	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 	if (ret < 0)
 		goto error;
@@ -2644,6 +2702,7 @@ delete:
 			break;
 		}
 		if (found_extent) {
+			btrfs_set_path_blocking(path);
 			ret = btrfs_free_extent(trans, root, extent_start,
 						extent_num_bytes,
 						leaf->start, root_owner,
@@ -2848,11 +2907,21 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
 	if (err)
 		return err;
 
-	if (S_ISREG(inode->i_mode) &&
-	    attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
-		err = btrfs_cont_expand(inode, attr->ia_size);
-		if (err)
-			return err;
+	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
+		if (attr->ia_size > inode->i_size) {
+			err = btrfs_cont_expand(inode, attr->ia_size);
+			if (err)
+				return err;
+		} else if (inode->i_size > 0 &&
+			   attr->ia_size == 0) {
+
+			/* we're truncating a file that used to have good
+			 * data down to zero.  Make sure it gets into
+			 * the ordered flush list so that any new writes
+			 * get down to disk quickly.
+			 */
+			BTRFS_I(inode)->ordered_data_close = 1;
+		}
 	}
 
 	err = inode_setattr(inode, attr);
@@ -2984,13 +3053,14 @@ static noinline void init_btrfs_i(struct inode *inode)
 	bi->disk_i_size = 0;
 	bi->flags = 0;
 	bi->index_cnt = (u64)-1;
-	bi->log_dirty_trans = 0;
+	bi->last_unlink_trans = 0;
 	extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS);
 	extent_io_tree_init(&BTRFS_I(inode)->io_tree,
 			     inode->i_mapping, GFP_NOFS);
 	extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree,
 			     inode->i_mapping, GFP_NOFS);
 	INIT_LIST_HEAD(&BTRFS_I(inode)->delalloc_inodes);
+	INIT_LIST_HEAD(&BTRFS_I(inode)->ordered_operations);
 	btrfs_ordered_inode_tree_init(&BTRFS_I(inode)->ordered_tree);
 	mutex_init(&BTRFS_I(inode)->extent_mutex);
 	mutex_init(&BTRFS_I(inode)->log_mutex);
@@ -3449,6 +3519,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	sizes[0] = sizeof(struct btrfs_inode_item);
 	sizes[1] = name_len + sizeof(*ref);
 
+	path->leave_spinning = 1;
 	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
 	if (ret != 0)
 		goto fail;
@@ -3727,6 +3798,8 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 		drop_inode = 1;
 
 	nr = trans->blocks_used;
+
+	btrfs_log_new_name(trans, inode, NULL, dentry->d_parent);
 	btrfs_end_transaction_throttle(trans, root);
 fail:
 	if (drop_inode) {
@@ -4363,6 +4436,8 @@ again:
 	}
 	ClearPageChecked(page);
 	set_page_dirty(page);
+
+	BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
 	unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 
 out_unlock:
@@ -4388,6 +4463,27 @@ static void btrfs_truncate(struct inode *inode)
 	btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
 
 	trans = btrfs_start_transaction(root, 1);
+
+	/*
+	 * setattr is responsible for setting the ordered_data_close flag,
+	 * but that is only tested during the last file release.  That
+	 * could happen well after the next commit, leaving a great big
+	 * window where new writes may get lost if someone chooses to write
+	 * to this file after truncating to zero
+	 *
+	 * The inode doesn't have any dirty data here, and so if we commit
+	 * this is a noop.  If someone immediately starts writing to the inode
+	 * it is very likely we'll catch some of their writes in this
+	 * transaction, and the commit will find this file on the ordered
+	 * data list with good things to send down.
+	 *
+	 * This is a best effort solution, there is still a window where
+	 * using truncate to replace the contents of the file will
+	 * end up with a zero length file after a crash.
+	 */
+	if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
+		btrfs_add_ordered_operation(trans, root, inode);
+
 	btrfs_set_trans_block_group(trans, inode);
 	btrfs_i_size_write(inode, inode->i_size);
 
@@ -4464,12 +4560,15 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->i_acl = BTRFS_ACL_NOT_CACHED;
 	ei->i_default_acl = BTRFS_ACL_NOT_CACHED;
 	INIT_LIST_HEAD(&ei->i_orphan);
+	INIT_LIST_HEAD(&ei->ordered_operations);
 	return &ei->vfs_inode;
 }
 
 void btrfs_destroy_inode(struct inode *inode)
 {
 	struct btrfs_ordered_extent *ordered;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+
 	WARN_ON(!list_empty(&inode->i_dentry));
 	WARN_ON(inode->i_data.nrpages);
 
@@ -4480,13 +4579,24 @@ void btrfs_destroy_inode(struct inode *inode)
 	    BTRFS_I(inode)->i_default_acl != BTRFS_ACL_NOT_CACHED)
 		posix_acl_release(BTRFS_I(inode)->i_default_acl);
 
-	spin_lock(&BTRFS_I(inode)->root->list_lock);
+	/*
+	 * Make sure we're properly removed from the ordered operation
+	 * lists.
+	 */
+	smp_mb();
+	if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
+		spin_lock(&root->fs_info->ordered_extent_lock);
+		list_del_init(&BTRFS_I(inode)->ordered_operations);
+		spin_unlock(&root->fs_info->ordered_extent_lock);
+	}
+
+	spin_lock(&root->list_lock);
 	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
 		printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
 		       " list\n", inode->i_ino);
 		dump_stack();
 	}
-	spin_unlock(&BTRFS_I(inode)->root->list_lock);
+	spin_unlock(&root->list_lock);
 
 	while (1) {
 		ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
@@ -4611,8 +4721,36 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (ret)
 		goto out_unlock;
 
+	/*
+	 * we're using rename to replace one file with another.
+	 * and the replacement file is large.  Start IO on it now so
+	 * we don't add too much work to the end of the transaction
+	 */
+	if (new_inode && old_inode && S_ISREG(old_inode->i_mode) &&
+	    new_inode->i_size &&
+	    old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
+		filemap_flush(old_inode->i_mapping);
+
 	trans = btrfs_start_transaction(root, 1);
 
+	/*
+	 * make sure the inode gets flushed if it is replacing
+	 * something.
+	 */
+	if (new_inode && new_inode->i_size &&
+	    old_inode && S_ISREG(old_inode->i_mode)) {
+		btrfs_add_ordered_operation(trans, root, old_inode);
+	}
+
+	/*
+	 * this is an ugly little race, but the rename is required to make
+	 * sure that if we crash, the inode is either at the old name
+	 * or the new one.  pinning the log transaction lets us make sure
+	 * we don't allow a log commit to come in after we unlink the
+	 * name but before we add the new name back in.
+	 */
+	btrfs_pin_log_trans(root);
+
 	btrfs_set_trans_block_group(trans, new_dir);
 
 	btrfs_inc_nlink(old_dentry->d_inode);
@@ -4620,6 +4758,9 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	new_dir->i_ctime = new_dir->i_mtime = ctime;
 	old_inode->i_ctime = ctime;
 
+	if (old_dentry->d_parent != new_dentry->d_parent)
+		btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
+
 	ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
 				 old_dentry->d_name.name,
 				 old_dentry->d_name.len);
@@ -4651,7 +4792,14 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (ret)
 		goto out_fail;
 
+	btrfs_log_new_name(trans, old_inode, old_dir,
+				       new_dentry->d_parent);
 out_fail:
+
+	/* this btrfs_end_log_trans just allows the current
+	 * log-sub transaction to complete
+	 */
+	btrfs_end_log_trans(root);
 	btrfs_end_transaction_throttle(trans, root);
 out_unlock:
 	return ret;

fs/btrfs/locking.c

@@ -71,12 +71,13 @@ void btrfs_clear_lock_blocking(struct extent_buffer *eb)
 static int btrfs_spin_on_block(struct extent_buffer *eb)
 {
 	int i;
+
 	for (i = 0; i < 512; i++) {
-		cpu_relax();
 		if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
 			return 1;
 		if (need_resched())
 			break;
+		cpu_relax();
 	}
 	return 0;
 }
@@ -95,13 +96,15 @@ int btrfs_try_spin_lock(struct extent_buffer *eb)
 {
 	int i;
 
-	spin_nested(eb);
-	if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
-		return 1;
-	spin_unlock(&eb->lock);
-
+	if (btrfs_spin_on_block(eb)) {
+		spin_nested(eb);
+		if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+			return 1;
+		spin_unlock(&eb->lock);
+	}
 	/* spin for a bit on the BLOCKING flag */
 	for (i = 0; i < 2; i++) {
+		cpu_relax();
 		if (!btrfs_spin_on_block(eb))
 			break;
 
@@ -148,6 +151,9 @@ int btrfs_tree_lock(struct extent_buffer *eb)
 	DEFINE_WAIT(wait);
 	wait.func = btrfs_wake_function;
 
+	if (!btrfs_spin_on_block(eb))
+		goto sleep;
+
 	while(1) {
 		spin_nested(eb);
 
@@ -165,9 +171,10 @@ int btrfs_tree_lock(struct extent_buffer *eb)
 		 * spin for a bit, and if the blocking flag goes away,
 		 * loop around
 		 */
+		cpu_relax();
 		if (btrfs_spin_on_block(eb))
 			continue;
-
+sleep:
 		prepare_to_wait_exclusive(&eb->lock_wq, &wait,
 					  TASK_UNINTERRUPTIBLE);
 

fs/btrfs/ordered-data.c

@@ -310,6 +310,16 @@ int btrfs_remove_ordered_extent(struct inode *inode,
 
 	spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
 	list_del_init(&entry->root_extent_list);
+
+	/*
+	 * we have no more ordered extents for this inode and
+	 * no dirty pages.  We can safely remove it from the
+	 * list of ordered extents
+	 */
+	if (RB_EMPTY_ROOT(&tree->tree) &&
+	    !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
+		list_del_init(&BTRFS_I(inode)->ordered_operations);
+	}
 	spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
 
 	mutex_unlock(&tree->mutex);
@@ -369,6 +379,68 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
 	return 0;
 }
 
+/*
+ * this is used during transaction commit to write all the inodes
+ * added to the ordered operation list.  These files must be fully on
+ * disk before the transaction commits.
+ *
+ * we have two modes here, one is to just start the IO via filemap_flush
+ * and the other is to wait for all the io.  When we wait, we have an
+ * extra check to make sure the ordered operation list really is empty
+ * before we return
+ */
+int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
+{
+	struct btrfs_inode *btrfs_inode;
+	struct inode *inode;
+	struct list_head splice;
+
+	INIT_LIST_HEAD(&splice);
+
+	mutex_lock(&root->fs_info->ordered_operations_mutex);
+	spin_lock(&root->fs_info->ordered_extent_lock);
+again:
+	list_splice_init(&root->fs_info->ordered_operations, &splice);
+
+	while (!list_empty(&splice)) {
+		btrfs_inode = list_entry(splice.next, struct btrfs_inode,
+				   ordered_operations);
+
+		inode = &btrfs_inode->vfs_inode;
+
+		list_del_init(&btrfs_inode->ordered_operations);
+
+		/*
+		 * the inode may be getting freed (in sys_unlink path).
+		 */
+		inode = igrab(inode);
+
+		if (!wait && inode) {
+			list_add_tail(&BTRFS_I(inode)->ordered_operations,
+			      &root->fs_info->ordered_operations);
+		}
+		spin_unlock(&root->fs_info->ordered_extent_lock);
+
+		if (inode) {
+			if (wait)
+				btrfs_wait_ordered_range(inode, 0, (u64)-1);
+			else
+				filemap_flush(inode->i_mapping);
+			iput(inode);
+		}
+
+		cond_resched();
+		spin_lock(&root->fs_info->ordered_extent_lock);
+	}
+	if (wait && !list_empty(&root->fs_info->ordered_operations))
+		goto again;
+
+	spin_unlock(&root->fs_info->ordered_extent_lock);
+	mutex_unlock(&root->fs_info->ordered_operations_mutex);
+
+	return 0;
+}
+
 /*
  * Used to start IO or wait for a given ordered extent to finish.
  *
@@ -726,3 +798,49 @@ int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
 
 	return ret;
 }
+
+/*
+ * add a given inode to the list of inodes that must be fully on
+ * disk before a transaction commit finishes.
+ *
+ * This basically gives us the ext3 style data=ordered mode, and it is mostly
+ * used to make sure renamed files are fully on disk.
+ *
+ * It is a noop if the inode is already fully on disk.
+ *
+ * If trans is not null, we'll do a friendly check for a transaction that
+ * is already flushing things and force the IO down ourselves.
+ */
+int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root,
+				struct inode *inode)
+{
+	u64 last_mod;
+
+	last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
+
+	/*
+	 * if this file hasn't been changed since the last transaction
+	 * commit, we can safely return without doing anything
+	 */
+	if (last_mod < root->fs_info->last_trans_committed)
+		return 0;
+
+	/*
+	 * the transaction is already committing.  Just start the IO and
+	 * don't bother with all of this list nonsense
+	 */
+	if (trans && root->fs_info->running_transaction->blocked) {
+		btrfs_wait_ordered_range(inode, 0, (u64)-1);
+		return 0;
+	}
+
+	spin_lock(&root->fs_info->ordered_extent_lock);
+	if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
+		list_add_tail(&BTRFS_I(inode)->ordered_operations,
+			      &root->fs_info->ordered_operations);
+	}
+	spin_unlock(&root->fs_info->ordered_extent_lock);
+
+	return 0;
+}

fs/btrfs/ordered-data.h

@@ -155,4 +155,8 @@ int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
 int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
 			   loff_t end, int sync_mode);
 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
+int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
+int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+				struct btrfs_root *root,
+				struct inode *inode);
 #endif

fs/btrfs/transaction.c

@@ -65,6 +65,15 @@ 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.num_heads_ready = 0;
+		cur_trans->delayed_refs.num_heads = 0;
+		cur_trans->delayed_refs.flushing = 0;
+		cur_trans->delayed_refs.run_delayed_start = 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 +191,8 @@ 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;
@@ -271,7 +282,6 @@ void btrfs_throttle(struct btrfs_root *root)
 	if (!root->fs_info->open_ioctl_trans)
 		wait_current_trans(root);
 	mutex_unlock(&root->fs_info->trans_mutex);
-
 	throttle_on_drops(root);
 }
 
@@ -280,6 +290,27 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_transaction *cur_trans;
 	struct btrfs_fs_info *info = root->fs_info;
+	int count = 0;
+
+	while (count < 4) {
+		unsigned long cur = trans->delayed_ref_updates;
+		trans->delayed_ref_updates = 0;
+		if (cur &&
+		    trans->transaction->delayed_refs.num_heads_ready > 64) {
+			trans->delayed_ref_updates = 0;
+
+			/*
+			 * do a full flush if the transaction is trying
+			 * to close
+			 */
+			if (trans->transaction->delayed_refs.flushing)
+				cur = 0;
+			btrfs_run_delayed_refs(trans, root, cur);
+		} else {
+			break;
+		}
+		count++;
+	}
 
 	mutex_lock(&info->trans_mutex);
 	cur_trans = info->running_transaction;
@@ -424,9 +455,10 @@ 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 +470,14 @@ 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 +491,18 @@ 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, 0);
+	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 +510,9 @@ 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;
 }
@@ -634,6 +672,31 @@ int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
 	return 0;
 }
 
+/*
+ * when dropping snapshots, we generate a ton of delayed refs, and it makes
+ * sense not to join the transaction while it is trying to flush the current
+ * queue of delayed refs out.
+ *
+ * This is used by the drop snapshot code only
+ */
+static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info)
+{
+	DEFINE_WAIT(wait);
+
+	mutex_lock(&info->trans_mutex);
+	while (info->running_transaction &&
+	       info->running_transaction->delayed_refs.flushing) {
+		prepare_to_wait(&info->transaction_wait, &wait,
+				TASK_UNINTERRUPTIBLE);
+		mutex_unlock(&info->trans_mutex);
+		schedule();
+		mutex_lock(&info->trans_mutex);
+		finish_wait(&info->transaction_wait, &wait);
+	}
+	mutex_unlock(&info->trans_mutex);
+	return 0;
+}
+
 /*
  * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
  * all of them
@@ -661,7 +724,22 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
 		atomic_inc(&root->fs_info->throttles);
 
 		while (1) {
+			/*
+			 * we don't want to jump in and create a bunch of
+			 * delayed refs if the transaction is starting to close
+			 */
+			wait_transaction_pre_flush(tree_root->fs_info);
 			trans = btrfs_start_transaction(tree_root, 1);
+
+			/*
+			 * we've joined a transaction, make sure it isn't
+			 * closing right now
+			 */
+			if (trans->transaction->delayed_refs.flushing) {
+				btrfs_end_transaction(trans, tree_root);
+				continue;
+			}
+
 			mutex_lock(&root->fs_info->drop_mutex);
 			ret = btrfs_drop_snapshot(trans, dirty->root);
 			if (ret != -EAGAIN)
@@ -766,7 +844,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 
 	old = btrfs_lock_root_node(root);
-	btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
+	btrfs_cow_block(trans, root, old, NULL, 0, &old);
 
 	btrfs_copy_root(trans, root, old, &tmp, objectid);
 	btrfs_tree_unlock(old);
@@ -894,12 +972,31 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	struct extent_io_tree *pinned_copy;
 	DEFINE_WAIT(wait);
 	int ret;
+	int should_grow = 0;
+	unsigned long now = get_seconds();
+
+	btrfs_run_ordered_operations(root, 0);
+
+	/* 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);
+
+	cur_trans = trans->transaction;
+	/*
+	 * set the flushing flag so procs in this transaction have to
+	 * start sending their work down.
+	 */
+	cur_trans->delayed_refs.flushing = 1;
+
+	ret = btrfs_run_delayed_refs(trans, root, 0);
+	BUG_ON(ret);
 
-	INIT_LIST_HEAD(&dirty_fs_roots);
 	mutex_lock(&root->fs_info->trans_mutex);
-	if (trans->transaction->in_commit) {
-		cur_trans = trans->transaction;
-		trans->transaction->use_count++;
+	INIT_LIST_HEAD(&dirty_fs_roots);
+	if (cur_trans->in_commit) {
+		cur_trans->use_count++;
 		mutex_unlock(&root->fs_info->trans_mutex);
 		btrfs_end_transaction(trans, root);
 
@@ -922,7 +1019,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
 	trans->transaction->in_commit = 1;
 	trans->transaction->blocked = 1;
-	cur_trans = trans->transaction;
 	if (cur_trans->list.prev != &root->fs_info->trans_list) {
 		prev_trans = list_entry(cur_trans->list.prev,
 					struct btrfs_transaction, list);
@@ -937,6 +1033,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 		}
 	}
 
+	if (now < cur_trans->start_time || now - cur_trans->start_time < 1)
+		should_grow = 1;
+
 	do {
 		int snap_pending = 0;
 		joined = cur_trans->num_joined;
@@ -949,7 +1048,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
 		if (cur_trans->num_writers > 1)
 			timeout = MAX_SCHEDULE_TIMEOUT;
-		else
+		else if (should_grow)
 			timeout = 1;
 
 		mutex_unlock(&root->fs_info->trans_mutex);
@@ -959,16 +1058,30 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 			BUG_ON(ret);
 		}
 
-		schedule_timeout(timeout);
+		/*
+		 * rename don't use btrfs_join_transaction, so, once we
+		 * set the transaction to blocked above, we aren't going
+		 * to get any new ordered operations.  We can safely run
+		 * it here and no for sure that nothing new will be added
+		 * to the list
+		 */
+		btrfs_run_ordered_operations(root, 1);
+
+		smp_mb();
+		if (cur_trans->num_writers > 1 || should_grow)
+			schedule_timeout(timeout);
 
 		mutex_lock(&root->fs_info->trans_mutex);
 		finish_wait(&cur_trans->writer_wait, &wait);
 	} while (cur_trans->num_writers > 1 ||
-		 (cur_trans->num_joined != joined));
+		 (should_grow && cur_trans->num_joined != joined));
 
 	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
@@ -1032,6 +1145,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	btrfs_copy_pinned(root, pinned_copy);
 
 	trans->transaction->blocked = 0;
+
 	wake_up(&root->fs_info->transaction_throttle);
 	wake_up(&root->fs_info->transaction_wait);
 
@@ -1058,6 +1172,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 	mutex_lock(&root->fs_info->trans_mutex);
 
 	cur_trans->commit_done = 1;
+
 	root->fs_info->last_trans_committed = cur_trans->transid;
 	wake_up(&cur_trans->commit_wait);
 

fs/btrfs/transaction.h

@@ -19,10 +19,16 @@
 #ifndef __BTRFS_TRANSACTION__
 #define __BTRFS_TRANSACTION__
 #include "btrfs_inode.h"
+#include "delayed-ref.h"
 
 struct btrfs_transaction {
 	u64 transid;
+	/*
+	 * total writers in this transaction, it must be zero before the
+	 * transaction can end
+	 */
 	unsigned long num_writers;
+
 	unsigned long num_joined;
 	int in_commit;
 	int use_count;
@@ -34,6 +40,7 @@ struct btrfs_transaction {
 	wait_queue_head_t writer_wait;
 	wait_queue_head_t commit_wait;
 	struct list_head pending_snapshots;
+	struct btrfs_delayed_ref_root delayed_refs;
 };
 
 struct btrfs_trans_handle {
@@ -44,6 +51,7 @@ struct btrfs_trans_handle {
 	u64 block_group;
 	u64 alloc_exclude_start;
 	u64 alloc_exclude_nr;
+	unsigned long delayed_ref_updates;
 };
 
 struct btrfs_pending_snapshot {

fs/btrfs/tree-defrag.c

@@ -124,8 +124,6 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
 	}
 
 	btrfs_release_path(root, path);
-	if (is_extent)
-		btrfs_extent_post_op(trans, root);
 out:
 	if (path)
 		btrfs_free_path(path);

fs/btrfs/tree-log.c

@@ -34,6 +34,49 @@
 #define LOG_INODE_ALL 0
 #define LOG_INODE_EXISTS 1
 
+/*
+ * directory trouble cases
+ *
+ * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
+ * log, we must force a full commit before doing an fsync of the directory
+ * where the unlink was done.
+ * ---> record transid of last unlink/rename per directory
+ *
+ * mkdir foo/some_dir
+ * normal commit
+ * rename foo/some_dir foo2/some_dir
+ * mkdir foo/some_dir
+ * fsync foo/some_dir/some_file
+ *
+ * The fsync above will unlink the original some_dir without recording
+ * it in its new location (foo2).  After a crash, some_dir will be gone
+ * unless the fsync of some_file forces a full commit
+ *
+ * 2) we must log any new names for any file or dir that is in the fsync
+ * log. ---> check inode while renaming/linking.
+ *
+ * 2a) we must log any new names for any file or dir during rename
+ * when the directory they are being removed from was logged.
+ * ---> check inode and old parent dir during rename
+ *
+ *  2a is actually the more important variant.  With the extra logging
+ *  a crash might unlink the old name without recreating the new one
+ *
+ * 3) after a crash, we must go through any directories with a link count
+ * of zero and redo the rm -rf
+ *
+ * mkdir f1/foo
+ * normal commit
+ * rm -rf f1/foo
+ * fsync(f1)
+ *
+ * The directory f1 was fully removed from the FS, but fsync was never
+ * called on f1, only its parent dir.  After a crash the rm -rf must
+ * be replayed.  This must be able to recurse down the entire
+ * directory tree.  The inode link count fixup code takes care of the
+ * ugly details.
+ */
+
 /*
  * stages for the tree walking.  The first
  * stage (0) is to only pin down the blocks we find
@@ -47,12 +90,17 @@
 #define LOG_WALK_REPLAY_INODES 1
 #define LOG_WALK_REPLAY_ALL 2
 
-static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root, struct inode *inode,
 			     int inode_only);
 static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid);
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+				       struct btrfs_root *root,
+				       struct btrfs_root *log,
+				       struct btrfs_path *path,
+				       u64 dirid, int del_all);
 
 /*
  * tree logging is a special write ahead log used to make sure that
@@ -132,11 +180,26 @@ static int join_running_log_trans(struct btrfs_root *root)
 	return ret;
 }
 
+/*
+ * This either makes the current running log transaction wait
+ * until you call btrfs_end_log_trans() or it makes any future
+ * log transactions wait until you call btrfs_end_log_trans()
+ */
+int btrfs_pin_log_trans(struct btrfs_root *root)
+{
+	int ret = -ENOENT;
+
+	mutex_lock(&root->log_mutex);
+	atomic_inc(&root->log_writers);
+	mutex_unlock(&root->log_mutex);
+	return ret;
+}
+
 /*
  * indicate we're done making changes to the log tree
  * and wake up anyone waiting to do a sync
  */
-static int end_log_trans(struct btrfs_root *root)
+int btrfs_end_log_trans(struct btrfs_root *root)
 {
 	if (atomic_dec_and_test(&root->log_writers)) {
 		smp_mb();
@@ -203,7 +266,6 @@ static int process_one_buffer(struct btrfs_root *log,
 		mutex_lock(&log->fs_info->pinned_mutex);
 		btrfs_update_pinned_extents(log->fs_info->extent_root,
 					    eb->start, eb->len, 1);
-		mutex_unlock(&log->fs_info->pinned_mutex);
 	}
 
 	if (btrfs_buffer_uptodate(eb, gen)) {
@@ -603,6 +665,7 @@ static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
 
 	ret = link_to_fixup_dir(trans, root, path, location.objectid);
 	BUG_ON(ret);
+
 	ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
 	BUG_ON(ret);
 	kfree(name);
@@ -804,6 +867,7 @@ conflict_again:
 					    victim_name_len)) {
 				btrfs_inc_nlink(inode);
 				btrfs_release_path(root, path);
+
 				ret = btrfs_unlink_inode(trans, root, dir,
 							 inode, victim_name,
 							 victim_name_len);
@@ -922,13 +986,20 @@ static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
 		key.offset--;
 		btrfs_release_path(root, path);
 	}
-	btrfs_free_path(path);
+	btrfs_release_path(root, path);
 	if (nlink != inode->i_nlink) {
 		inode->i_nlink = nlink;
 		btrfs_update_inode(trans, root, inode);
 	}
 	BTRFS_I(inode)->index_cnt = (u64)-1;
 
+	if (inode->i_nlink == 0 && S_ISDIR(inode->i_mode)) {
+		ret = replay_dir_deletes(trans, root, NULL, path,
+					 inode->i_ino, 1);
+		BUG_ON(ret);
+	}
+	btrfs_free_path(path);
+
 	return 0;
 }
 
@@ -971,9 +1042,12 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
 
 		iput(inode);
 
-		if (key.offset == 0)
-			break;
-		key.offset--;
+		/*
+		 * fixup on a directory may create new entries,
+		 * make sure we always look for the highset possible
+		 * offset
+		 */
+		key.offset = (u64)-1;
 	}
 	btrfs_release_path(root, path);
 	return 0;
@@ -1313,11 +1387,11 @@ again:
 		read_extent_buffer(eb, name, (unsigned long)(di + 1),
 				  name_len);
 		log_di = NULL;
-		if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
+		if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
 			log_di = btrfs_lookup_dir_item(trans, log, log_path,
 						       dir_key->objectid,
 						       name, name_len, 0);
-		} else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
+		} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
 			log_di = btrfs_lookup_dir_index_item(trans, log,
 						     log_path,
 						     dir_key->objectid,
@@ -1378,7 +1452,7 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
 				       struct btrfs_root *root,
 				       struct btrfs_root *log,
 				       struct btrfs_path *path,
-				       u64 dirid)
+				       u64 dirid, int del_all)
 {
 	u64 range_start;
 	u64 range_end;
@@ -1408,10 +1482,14 @@ again:
 	range_start = 0;
 	range_end = 0;
 	while (1) {
-		ret = find_dir_range(log, path, dirid, key_type,
-				     &range_start, &range_end);
-		if (ret != 0)
-			break;
+		if (del_all)
+			range_end = (u64)-1;
+		else {
+			ret = find_dir_range(log, path, dirid, key_type,
+					     &range_start, &range_end);
+			if (ret != 0)
+				break;
+		}
 
 		dir_key.offset = range_start;
 		while (1) {
@@ -1437,7 +1515,8 @@ again:
 				break;
 
 			ret = check_item_in_log(trans, root, log, path,
-						log_path, dir, &found_key);
+						log_path, dir,
+						&found_key);
 			BUG_ON(ret);
 			if (found_key.offset == (u64)-1)
 				break;
@@ -1514,7 +1593,7 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
 			mode = btrfs_inode_mode(eb, inode_item);
 			if (S_ISDIR(mode)) {
 				ret = replay_dir_deletes(wc->trans,
-					 root, log, path, key.objectid);
+					 root, log, path, key.objectid, 0);
 				BUG_ON(ret);
 			}
 			ret = overwrite_item(wc->trans, root, path,
@@ -1533,6 +1612,17 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
 					root, inode, inode->i_size,
 					BTRFS_EXTENT_DATA_KEY);
 				BUG_ON(ret);
+
+				/* if the nlink count is zero here, the iput
+				 * will free the inode.  We bump it to make
+				 * sure it doesn't get freed until the link
+				 * count fixup is done
+				 */
+				if (inode->i_nlink == 0) {
+					btrfs_inc_nlink(inode);
+					btrfs_update_inode(wc->trans,
+							   root, inode);
+				}
 				iput(inode);
 			}
 			ret = link_to_fixup_dir(wc->trans, root,
@@ -1840,7 +1930,8 @@ static int update_log_root(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static int wait_log_commit(struct btrfs_root *root, unsigned long transid)
+static int wait_log_commit(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root, unsigned long transid)
 {
 	DEFINE_WAIT(wait);
 	int index = transid % 2;
@@ -1854,9 +1945,12 @@ static int wait_log_commit(struct btrfs_root *root, unsigned long transid)
 		prepare_to_wait(&root->log_commit_wait[index],
 				&wait, TASK_UNINTERRUPTIBLE);
 		mutex_unlock(&root->log_mutex);
-		if (root->log_transid < transid + 2 &&
+
+		if (root->fs_info->last_trans_log_full_commit !=
+		    trans->transid && root->log_transid < transid + 2 &&
 		    atomic_read(&root->log_commit[index]))
 			schedule();
+
 		finish_wait(&root->log_commit_wait[index], &wait);
 		mutex_lock(&root->log_mutex);
 	} while (root->log_transid < transid + 2 &&
@@ -1864,14 +1958,16 @@ static int wait_log_commit(struct btrfs_root *root, unsigned long transid)
 	return 0;
 }
 
-static int wait_for_writer(struct btrfs_root *root)
+static int wait_for_writer(struct btrfs_trans_handle *trans,
+			   struct btrfs_root *root)
 {
 	DEFINE_WAIT(wait);
 	while (atomic_read(&root->log_writers)) {
 		prepare_to_wait(&root->log_writer_wait,
 				&wait, TASK_UNINTERRUPTIBLE);
 		mutex_unlock(&root->log_mutex);
-		if (atomic_read(&root->log_writers))
+		if (root->fs_info->last_trans_log_full_commit !=
+		    trans->transid && atomic_read(&root->log_writers))
 			schedule();
 		mutex_lock(&root->log_mutex);
 		finish_wait(&root->log_writer_wait, &wait);
@@ -1882,7 +1978,14 @@ static int wait_for_writer(struct btrfs_root *root)
 /*
  * btrfs_sync_log does sends a given tree log down to the disk and
  * updates the super blocks to record it.  When this call is done,
- * you know that any inodes previously logged are safely on disk
+ * you know that any inodes previously logged are safely on disk only
+ * if it returns 0.
+ *
+ * Any other return value means you need to call btrfs_commit_transaction.
+ * Some of the edge cases for fsyncing directories that have had unlinks
+ * or renames done in the past mean that sometimes the only safe
+ * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
+ * that has happened.
  */
 int btrfs_sync_log(struct btrfs_trans_handle *trans,
 		   struct btrfs_root *root)
@@ -1896,7 +1999,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	mutex_lock(&root->log_mutex);
 	index1 = root->log_transid % 2;
 	if (atomic_read(&root->log_commit[index1])) {
-		wait_log_commit(root, root->log_transid);
+		wait_log_commit(trans, root, root->log_transid);
 		mutex_unlock(&root->log_mutex);
 		return 0;
 	}
@@ -1904,18 +2007,26 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
 	/* wait for previous tree log sync to complete */
 	if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
-		wait_log_commit(root, root->log_transid - 1);
+		wait_log_commit(trans, root, root->log_transid - 1);
 
 	while (1) {
 		unsigned long batch = root->log_batch;
 		mutex_unlock(&root->log_mutex);
 		schedule_timeout_uninterruptible(1);
 		mutex_lock(&root->log_mutex);
-		wait_for_writer(root);
+
+		wait_for_writer(trans, root);
 		if (batch == root->log_batch)
 			break;
 	}
 
+	/* bail out if we need to do a full commit */
+	if (root->fs_info->last_trans_log_full_commit == trans->transid) {
+		ret = -EAGAIN;
+		mutex_unlock(&root->log_mutex);
+		goto out;
+	}
+
 	ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
 	BUG_ON(ret);
 
@@ -1951,16 +2062,29 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
 	index2 = log_root_tree->log_transid % 2;
 	if (atomic_read(&log_root_tree->log_commit[index2])) {
-		wait_log_commit(log_root_tree, log_root_tree->log_transid);
+		wait_log_commit(trans, log_root_tree,
+				log_root_tree->log_transid);
 		mutex_unlock(&log_root_tree->log_mutex);
 		goto out;
 	}
 	atomic_set(&log_root_tree->log_commit[index2], 1);
 
-	if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2]))
-		wait_log_commit(log_root_tree, log_root_tree->log_transid - 1);
+	if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
+		wait_log_commit(trans, log_root_tree,
+				log_root_tree->log_transid - 1);
+	}
+
+	wait_for_writer(trans, log_root_tree);
 
-	wait_for_writer(log_root_tree);
+	/*
+	 * now that we've moved on to the tree of log tree roots,
+	 * check the full commit flag again
+	 */
+	if (root->fs_info->last_trans_log_full_commit == trans->transid) {
+		mutex_unlock(&log_root_tree->log_mutex);
+		ret = -EAGAIN;
+		goto out_wake_log_root;
+	}
 
 	ret = btrfs_write_and_wait_marked_extents(log_root_tree,
 				&log_root_tree->dirty_log_pages);
@@ -1985,7 +2109,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	 * in and cause problems either.
 	 */
 	write_ctree_super(trans, root->fs_info->tree_root, 2);
+	ret = 0;
 
+out_wake_log_root:
 	atomic_set(&log_root_tree->log_commit[index2], 0);
 	smp_mb();
 	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
@@ -1998,7 +2124,8 @@ out:
 	return 0;
 }
 
-/* * free all the extents used by the tree log.  This should be called
+/*
+ * free all the extents used by the tree log.  This should be called
  * at commit time of the full transaction
  */
 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
@@ -2132,7 +2259,7 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 
 	btrfs_free_path(path);
 	mutex_unlock(&BTRFS_I(dir)->log_mutex);
-	end_log_trans(root);
+	btrfs_end_log_trans(root);
 
 	return 0;
 }
@@ -2159,7 +2286,7 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
 	ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
 				  dirid, &index);
 	mutex_unlock(&BTRFS_I(inode)->log_mutex);
-	end_log_trans(root);
+	btrfs_end_log_trans(root);
 
 	return ret;
 }
@@ -2559,7 +2686,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
  *
  * This handles both files and directories.
  */
-static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root, struct inode *inode,
 			     int inode_only)
 {
@@ -2585,28 +2712,17 @@ static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
 	min_key.offset = 0;
 
 	max_key.objectid = inode->i_ino;
+
+	/* today the code can only do partial logging of directories */
+	if (!S_ISDIR(inode->i_mode))
+	    inode_only = LOG_INODE_ALL;
+
 	if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
 		max_key.type = BTRFS_XATTR_ITEM_KEY;
 	else
 		max_key.type = (u8)-1;
 	max_key.offset = (u64)-1;
 
-	/*
-	 * if this inode has already been logged and we're in inode_only
-	 * mode, we don't want to delete the things that have already
-	 * been written to the log.
-	 *
-	 * But, if the inode has been through an inode_only log,
-	 * the logged_trans field is not set.  This allows us to catch
-	 * any new names for this inode in the backrefs by logging it
-	 * again
-	 */
-	if (inode_only == LOG_INODE_EXISTS &&
-	    BTRFS_I(inode)->logged_trans == trans->transid) {
-		btrfs_free_path(path);
-		btrfs_free_path(dst_path);
-		goto out;
-	}
 	mutex_lock(&BTRFS_I(inode)->log_mutex);
 
 	/*
@@ -2693,7 +2809,6 @@ next_slot:
 	if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
 		btrfs_release_path(root, path);
 		btrfs_release_path(log, dst_path);
-		BTRFS_I(inode)->log_dirty_trans = 0;
 		ret = log_directory_changes(trans, root, inode, path, dst_path);
 		BUG_ON(ret);
 	}
@@ -2702,19 +2817,69 @@ next_slot:
 
 	btrfs_free_path(path);
 	btrfs_free_path(dst_path);
-out:
 	return 0;
 }
 
-int btrfs_log_inode(struct btrfs_trans_handle *trans,
-		    struct btrfs_root *root, struct inode *inode,
-		    int inode_only)
+/*
+ * follow the dentry parent pointers up the chain and see if any
+ * of the directories in it require a full commit before they can
+ * be logged.  Returns zero if nothing special needs to be done or 1 if
+ * a full commit is required.
+ */
+static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
+					       struct inode *inode,
+					       struct dentry *parent,
+					       struct super_block *sb,
+					       u64 last_committed)
 {
-	int ret;
+	int ret = 0;
+	struct btrfs_root *root;
 
-	start_log_trans(trans, root);
-	ret = __btrfs_log_inode(trans, root, inode, inode_only);
-	end_log_trans(root);
+	/*
+	 * for regular files, if its inode is already on disk, we don't
+	 * have to worry about the parents at all.  This is because
+	 * we can use the last_unlink_trans field to record renames
+	 * and other fun in this file.
+	 */
+	if (S_ISREG(inode->i_mode) &&
+	    BTRFS_I(inode)->generation <= last_committed &&
+	    BTRFS_I(inode)->last_unlink_trans <= last_committed)
+			goto out;
+
+	if (!S_ISDIR(inode->i_mode)) {
+		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
+			goto out;
+		inode = parent->d_inode;
+	}
+
+	while (1) {
+		BTRFS_I(inode)->logged_trans = trans->transid;
+		smp_mb();
+
+		if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
+			root = BTRFS_I(inode)->root;
+
+			/*
+			 * make sure any commits to the log are forced
+			 * to be full commits
+			 */
+			root->fs_info->last_trans_log_full_commit =
+				trans->transid;
+			ret = 1;
+			break;
+		}
+
+		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
+			break;
+
+		if (parent == sb->s_root)
+			break;
+
+		parent = parent->d_parent;
+		inode = parent->d_inode;
+
+	}
+out:
 	return ret;
 }
 
@@ -2724,31 +2889,65 @@ int btrfs_log_inode(struct btrfs_trans_handle *trans,
  * only logging is done of any parent directories that are older than
  * the last committed transaction
  */
-int btrfs_log_dentry(struct btrfs_trans_handle *trans,
-		    struct btrfs_root *root, struct dentry *dentry)
+int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
+		    struct btrfs_root *root, struct inode *inode,
+		    struct dentry *parent, int exists_only)
 {
-	int inode_only = LOG_INODE_ALL;
+	int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
 	struct super_block *sb;
-	int ret;
+	int ret = 0;
+	u64 last_committed = root->fs_info->last_trans_committed;
+
+	sb = inode->i_sb;
+
+	if (root->fs_info->last_trans_log_full_commit >
+	    root->fs_info->last_trans_committed) {
+		ret = 1;
+		goto end_no_trans;
+	}
+
+	ret = check_parent_dirs_for_sync(trans, inode, parent,
+					 sb, last_committed);
+	if (ret)
+		goto end_no_trans;
 
 	start_log_trans(trans, root);
-	sb = dentry->d_inode->i_sb;
-	while (1) {
-		ret = __btrfs_log_inode(trans, root, dentry->d_inode,
-					inode_only);
-		BUG_ON(ret);
-		inode_only = LOG_INODE_EXISTS;
 
-		dentry = dentry->d_parent;
-		if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
+	ret = btrfs_log_inode(trans, root, inode, inode_only);
+	BUG_ON(ret);
+
+	/*
+	 * for regular files, if its inode is already on disk, we don't
+	 * have to worry about the parents at all.  This is because
+	 * we can use the last_unlink_trans field to record renames
+	 * and other fun in this file.
+	 */
+	if (S_ISREG(inode->i_mode) &&
+	    BTRFS_I(inode)->generation <= last_committed &&
+	    BTRFS_I(inode)->last_unlink_trans <= last_committed)
+			goto no_parent;
+
+	inode_only = LOG_INODE_EXISTS;
+	while (1) {
+		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
 			break;
 
-		if (BTRFS_I(dentry->d_inode)->generation <=
-		    root->fs_info->last_trans_committed)
+		inode = parent->d_inode;
+		if (BTRFS_I(inode)->generation >
+		    root->fs_info->last_trans_committed) {
+			ret = btrfs_log_inode(trans, root, inode, inode_only);
+			BUG_ON(ret);
+		}
+		if (parent == sb->s_root)
 			break;
+
+		parent = parent->d_parent;
 	}
-	end_log_trans(root);
-	return 0;
+no_parent:
+	ret = 0;
+	btrfs_end_log_trans(root);
+end_no_trans:
+	return ret;
 }
 
 /*
@@ -2760,12 +2959,8 @@ int btrfs_log_dentry(struct btrfs_trans_handle *trans,
 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, struct dentry *dentry)
 {
-	u64 gen;
-	gen = root->fs_info->last_trans_new_blockgroup;
-	if (gen > root->fs_info->last_trans_committed)
-		return 1;
-	else
-		return btrfs_log_dentry(trans, root, dentry);
+	return btrfs_log_inode_parent(trans, root, dentry->d_inode,
+				      dentry->d_parent, 0);
 }
 
 /*
@@ -2884,3 +3079,94 @@ again:
 	kfree(log_root_tree);
 	return 0;
 }
+
+/*
+ * there are some corner cases where we want to force a full
+ * commit instead of allowing a directory to be logged.
+ *
+ * They revolve around files there were unlinked from the directory, and
+ * this function updates the parent directory so that a full commit is
+ * properly done if it is fsync'd later after the unlinks are done.
+ */
+void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
+			     struct inode *dir, struct inode *inode,
+			     int for_rename)
+{
+	/*
+	 * when we're logging a file, if it hasn't been renamed
+	 * or unlinked, and its inode is fully committed on disk,
+	 * we don't have to worry about walking up the directory chain
+	 * to log its parents.
+	 *
+	 * So, we use the last_unlink_trans field to put this transid
+	 * into the file.  When the file is logged we check it and
+	 * don't log the parents if the file is fully on disk.
+	 */
+	if (S_ISREG(inode->i_mode))
+		BTRFS_I(inode)->last_unlink_trans = trans->transid;
+
+	/*
+	 * if this directory was already logged any new
+	 * names for this file/dir will get recorded
+	 */
+	smp_mb();
+	if (BTRFS_I(dir)->logged_trans == trans->transid)
+		return;
+
+	/*
+	 * if the inode we're about to unlink was logged,
+	 * the log will be properly updated for any new names
+	 */
+	if (BTRFS_I(inode)->logged_trans == trans->transid)
+		return;
+
+	/*
+	 * when renaming files across directories, if the directory
+	 * there we're unlinking from gets fsync'd later on, there's
+	 * no way to find the destination directory later and fsync it
+	 * properly.  So, we have to be conservative and force commits
+	 * so the new name gets discovered.
+	 */
+	if (for_rename)
+		goto record;
+
+	/* we can safely do the unlink without any special recording */
+	return;
+
+record:
+	BTRFS_I(dir)->last_unlink_trans = trans->transid;
+}
+
+/*
+ * Call this after adding a new name for a file and it will properly
+ * update the log to reflect the new name.
+ *
+ * It will return zero if all goes well, and it will return 1 if a
+ * full transaction commit is required.
+ */
+int btrfs_log_new_name(struct btrfs_trans_handle *trans,
+			struct inode *inode, struct inode *old_dir,
+			struct dentry *parent)
+{
+	struct btrfs_root * root = BTRFS_I(inode)->root;
+
+	/*
+	 * this will force the logging code to walk the dentry chain
+	 * up for the file
+	 */
+	if (S_ISREG(inode->i_mode))
+		BTRFS_I(inode)->last_unlink_trans = trans->transid;
+
+	/*
+	 * if this inode hasn't been logged and directory we're renaming it
+	 * from hasn't been logged, we don't need to log it
+	 */
+	if (BTRFS_I(inode)->logged_trans <=
+	    root->fs_info->last_trans_committed &&
+	    (!old_dir || BTRFS_I(old_dir)->logged_trans <=
+		    root->fs_info->last_trans_committed))
+		return 0;
+
+	return btrfs_log_inode_parent(trans, root, inode, parent, 1);
+}
+

fs/btrfs/tree-log.h

@@ -22,14 +22,9 @@
 int btrfs_sync_log(struct btrfs_trans_handle *trans,
 		   struct btrfs_root *root);
 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root);
-int btrfs_log_dentry(struct btrfs_trans_handle *trans,
-		    struct btrfs_root *root, struct dentry *dentry);
 int btrfs_recover_log_trees(struct btrfs_root *tree_root);
 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, struct dentry *dentry);
-int btrfs_log_inode(struct btrfs_trans_handle *trans,
-		    struct btrfs_root *root, struct inode *inode,
-		    int inode_only);
 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 const char *name, int name_len,
@@ -38,4 +33,16 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root,
 			       const char *name, int name_len,
 			       struct inode *inode, u64 dirid);
+int btrfs_join_running_log_trans(struct btrfs_root *root);
+int btrfs_end_log_trans(struct btrfs_root *root);
+int btrfs_pin_log_trans(struct btrfs_root *root);
+int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
+		    struct btrfs_root *root, struct inode *inode,
+		    struct dentry *parent, int exists_only);
+void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
+			     struct inode *dir, struct inode *inode,
+			     int for_rename);
+int btrfs_log_new_name(struct btrfs_trans_handle *trans,
+			struct inode *inode, struct inode *old_dir,
+			struct dentry *parent);
 #endif