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.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

+/*
+ * 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

+/*
+ * 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 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 	} 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 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 	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 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 		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 @@ noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 			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 @@ noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 							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 @@ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
 	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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 		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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 			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 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 
 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/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.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.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