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: BUG to BUG_ON changes
Btrfs: remove dead code
Btrfs: remove dead code
Btrfs: fix typos in comments
Btrfs: remove unused ftrace include
Btrfs: fix __ucmpdi2 compile bug on 32 bit builds
Btrfs: free inode struct when btrfs_new_inode fails
Btrfs: fix race in worker_loop
Btrfs: add flushoncommit mount option
Btrfs: notreelog mount option
Btrfs: introduce btrfs_show_options
Btrfs: rework allocation clustering
Btrfs: Optimize locking in btrfs_next_leaf()
Btrfs: break up btrfs_search_slot into smaller pieces
Btrfs: kill the pinned_mutex
Btrfs: kill the block group alloc mutex
Btrfs: clean up find_free_extent
Btrfs: free space cache cleanups
Btrfs: unplug in the async bio submission threads
Btrfs: keep processing bios for a given bdev if our proc is batching

fs/btrfs/async-thread.c

···
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
-#include <linux/ftrace.h>
 #include "async-thread.h"
 
 #define WORK_QUEUED_BIT 0
···
 				if (!list_empty(&worker->pending))
 					continue;
 
+				if (kthread_should_stop())
+					break;
+
 				/* still no more work?, sleep for real */
 				spin_lock_irq(&worker->lock);
 				set_current_state(TASK_INTERRUPTIBLE);
···
 				worker->working = 0;
 				spin_unlock_irq(&worker->lock);
 
-				schedule();
+				if (!kthread_should_stop())
+					schedule();
 			}
 			__set_current_state(TASK_RUNNING);
 		}

fs/btrfs/ctree.c

···
  * readahead one full node of leaves, finding things that are close
  * to the block in 'slot', and triggering ra on them.
  */
-static noinline void reada_for_search(struct btrfs_root *root,
-				      struct btrfs_path *path,
-				      int level, int slot, u64 objectid)
+static void reada_for_search(struct btrfs_root *root,
+			     struct btrfs_path *path,
+			     int level, int slot, u64 objectid)
 {
 	struct extent_buffer *node;
 	struct btrfs_disk_key disk_key;
···
 }
 
 /*
+ * helper function for btrfs_search_slot.  The goal is to find a block
+ * in cache without setting the path to blocking.  If we find the block
+ * we return zero and the path is unchanged.
+ *
+ * If we can't find the block, we set the path blocking and do some
+ * reada.  -EAGAIN is returned and the search must be repeated.
+ */
+static int
+read_block_for_search(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root, struct btrfs_path *p,
+		       struct extent_buffer **eb_ret, int level, int slot,
+		       struct btrfs_key *key)
+{
+	u64 blocknr;
+	u64 gen;
+	u32 blocksize;
+	struct extent_buffer *b = *eb_ret;
+	struct extent_buffer *tmp;
+
+	blocknr = btrfs_node_blockptr(b, slot);
+	gen = btrfs_node_ptr_generation(b, slot);
+	blocksize = btrfs_level_size(root, level - 1);
+
+	tmp = btrfs_find_tree_block(root, blocknr, blocksize);
+	if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+		*eb_ret = tmp;
+		return 0;
+	}
+
+	/*
+	 * reduce lock contention at high levels
+	 * of the btree by dropping locks before
+	 * we read.
+	 */
+	btrfs_release_path(NULL, p);
+	if (tmp)
+		free_extent_buffer(tmp);
+	if (p->reada)
+		reada_for_search(root, p, level, slot, key->objectid);
+
+	tmp = read_tree_block(root, blocknr, blocksize, gen);
+	if (tmp)
+		free_extent_buffer(tmp);
+	return -EAGAIN;
+}
+
+/*
+ * helper function for btrfs_search_slot.  This does all of the checks
+ * for node-level blocks and does any balancing required based on
+ * the ins_len.
+ *
+ * If no extra work was required, zero is returned.  If we had to
+ * drop the path, -EAGAIN is returned and btrfs_search_slot must
+ * start over
+ */
+static int
+setup_nodes_for_search(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root, struct btrfs_path *p,
+		       struct extent_buffer *b, int level, int ins_len)
+{
+	int ret;
+	if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
+	    BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
+		int sret;
+
+		sret = reada_for_balance(root, p, level);
+		if (sret)
+			goto again;
+
+		btrfs_set_path_blocking(p);
+		sret = split_node(trans, root, p, level);
+		btrfs_clear_path_blocking(p, NULL);
+
+		BUG_ON(sret > 0);
+		if (sret) {
+			ret = sret;
+			goto done;
+		}
+		b = p->nodes[level];
+	} else if (ins_len < 0 && btrfs_header_nritems(b) <
+		   BTRFS_NODEPTRS_PER_BLOCK(root) / 4) {
+		int sret;
+
+		sret = reada_for_balance(root, p, level);
+		if (sret)
+			goto again;
+
+		btrfs_set_path_blocking(p);
+		sret = balance_level(trans, root, p, level);
+		btrfs_clear_path_blocking(p, NULL);
+
+		if (sret) {
+			ret = sret;
+			goto done;
+		}
+		b = p->nodes[level];
+		if (!b) {
+			btrfs_release_path(NULL, p);
+			goto again;
+		}
+		BUG_ON(btrfs_header_nritems(b) == 1);
+	}
+	return 0;
+
+again:
+	ret = -EAGAIN;
+done:
+	return ret;
+}
+
+/*
  * look for key in the tree.  path is filled in with nodes along the way
  * if key is found, we return zero and you can find the item in the leaf
  * level of the path (level 0)
···
 		      ins_len, int cow)
 {
 	struct extent_buffer *b;
-	struct extent_buffer *tmp;
 	int slot;
 	int ret;
 	int level;
-	int should_reada = p->reada;
 	int lowest_unlock = 1;
-	int blocksize;
 	u8 lowest_level = 0;
-	u64 blocknr;
-	u64 gen;
 
 	lowest_level = p->lowest_level;
 	WARN_ON(lowest_level && ins_len > 0);
···
 		if (cow) {
 			int wret;
 
-			/* is a cow on this block not required */
+			/*
+			 * if we don't really need to cow this block
+			 * then we don't want to set the path blocking,
+			 * so we test it here
+			 */
 			if (btrfs_header_generation(b) == trans->transid &&
 			    btrfs_header_owner(b) == root->root_key.objectid &&
 			    !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
···
 			if (ret && slot > 0)
 				slot -= 1;
 			p->slots[level] = slot;
-			if ((p->search_for_split || ins_len > 0) &&
-			    btrfs_header_nritems(b) >=
-			    BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
-				int sret;
+			ret = setup_nodes_for_search(trans, root, p, b, level,
+						     ins_len);
+			if (ret == -EAGAIN)
+				goto again;
+			else if (ret)
+				goto done;
+			b = p->nodes[level];
+			slot = p->slots[level];
 
-				sret = reada_for_balance(root, p, level);
-				if (sret)
-					goto again;
-
-				btrfs_set_path_blocking(p);
-				sret = split_node(trans, root, p, level);
-				btrfs_clear_path_blocking(p, NULL);
-
-				BUG_ON(sret > 0);
-				if (sret) {
-					ret = sret;
-					goto done;
-				}
-				b = p->nodes[level];
-				slot = p->slots[level];
-			} else if (ins_len < 0 &&
-				   btrfs_header_nritems(b) <
-				   BTRFS_NODEPTRS_PER_BLOCK(root) / 4) {
-				int sret;
-
-				sret = reada_for_balance(root, p, level);
-				if (sret)
-					goto again;
-
-				btrfs_set_path_blocking(p);
-				sret = balance_level(trans, root, p, level);
-				btrfs_clear_path_blocking(p, NULL);
-
-				if (sret) {
-					ret = sret;
-					goto done;
-				}
-				b = p->nodes[level];
-				if (!b) {
-					btrfs_release_path(NULL, p);
-					goto again;
-				}
-				slot = p->slots[level];
-				BUG_ON(btrfs_header_nritems(b) == 1);
-			}
 			unlock_up(p, level, lowest_unlock);
 
 			/* this is only true while dropping a snapshot */
···
 				goto done;
 			}
 
-			blocknr = btrfs_node_blockptr(b, slot);
-			gen = btrfs_node_ptr_generation(b, slot);
-			blocksize = btrfs_level_size(root, level - 1);
+			ret = read_block_for_search(trans, root, p,
+						    &b, level, slot, key);
+			if (ret == -EAGAIN)
+				goto again;
 
-			tmp = btrfs_find_tree_block(root, blocknr, blocksize);
-			if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
-				b = tmp;
-			} else {
-				/*
-				 * reduce lock contention at high levels
-				 * of the btree by dropping locks before
-				 * we read.
-				 */
-				if (level > 0) {
-					btrfs_release_path(NULL, p);
-					if (tmp)
-						free_extent_buffer(tmp);
-					if (should_reada)
-						reada_for_search(root, p,
-								 level, slot,
-								 key->objectid);
-
-					tmp = read_tree_block(root, blocknr,
-							 blocksize, gen);
-					if (tmp)
-						free_extent_buffer(tmp);
-					goto again;
-				} else {
-					btrfs_set_path_blocking(p);
-					if (tmp)
-						free_extent_buffer(tmp);
-					if (should_reada)
-						reada_for_search(root, p,
-								 level, slot,
-								 key->objectid);
-					b = read_node_slot(root, b, slot);
-				}
-			}
 			if (!p->skip_locking) {
 				int lret;
 
···
 	BUG_ON(!path->nodes[level]);
 	lower = path->nodes[level];
 	nritems = btrfs_header_nritems(lower);
-	if (slot > nritems)
-		BUG();
+	BUG_ON(slot > nritems);
 	if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
 		BUG();
 	if (slot != nritems) {
···
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
 	int slot;
-	int level = 1;
+	int level;
 	struct extent_buffer *c;
-	struct extent_buffer *next = NULL;
+	struct extent_buffer *next;
 	struct btrfs_key key;
 	u32 nritems;
 	int ret;
+	int old_spinning = path->leave_spinning;
+	int force_blocking = 0;
 
 	nritems = btrfs_header_nritems(path->nodes[0]);
 	if (nritems == 0)
 		return 1;
 
-	btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+	/*
+	 * we take the blocks in an order that upsets lockdep.  Using
+	 * blocking mode is the only way around it.
+	 */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	force_blocking = 1;
+#endif
 
+	btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
+again:
+	level = 1;
+	next = NULL;
 	btrfs_release_path(root, path);
+
 	path->keep_locks = 1;
+
+	if (!force_blocking)
+		path->leave_spinning = 1;
+
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	path->keep_locks = 0;
 
 	if (ret < 0)
 		return ret;
 
-	btrfs_set_path_blocking(path);
 	nritems = btrfs_header_nritems(path->nodes[0]);
 	/*
 	 * by releasing the path above we dropped all our locks.  A balance
···
 	 */
 	if (nritems > 0 && path->slots[0] < nritems - 1) {
 		path->slots[0]++;
+		ret = 0;
 		goto done;
 	}
 
 	while (level < BTRFS_MAX_LEVEL) {
-		if (!path->nodes[level])
-			return 1;
+		if (!path->nodes[level]) {
+			ret = 1;
+			goto done;
+		}
 
 		slot = path->slots[level] + 1;
 		c = path->nodes[level];
 		if (slot >= btrfs_header_nritems(c)) {
 			level++;
-			if (level == BTRFS_MAX_LEVEL)
-				return 1;
+			if (level == BTRFS_MAX_LEVEL) {
+				ret = 1;
+				goto done;
+			}
 			continue;
 		}
 
···
 			free_extent_buffer(next);
 		}
 
-		/* the path was set to blocking above */
-		if (level == 1 && (path->locks[1] || path->skip_locking) &&
-		    path->reada)
-			reada_for_search(root, path, level, slot, 0);
+		next = c;
+		ret = read_block_for_search(NULL, root, path, &next, level,
+					    slot, &key);
+		if (ret == -EAGAIN)
+			goto again;
 
-		next = read_node_slot(root, c, slot);
 		if (!path->skip_locking) {
-			btrfs_assert_tree_locked(c);
-			btrfs_tree_lock(next);
-			btrfs_set_lock_blocking(next);
+			ret = btrfs_try_spin_lock(next);
+			if (!ret) {
+				btrfs_set_path_blocking(path);
+				btrfs_tree_lock(next);
+				if (!force_blocking)
+					btrfs_clear_path_blocking(path, next);
+			}
+			if (force_blocking)
+				btrfs_set_lock_blocking(next);
 		}
 		break;
 	}
···
 		c = path->nodes[level];
 		if (path->locks[level])
 			btrfs_tree_unlock(c);
+
 		free_extent_buffer(c);
 		path->nodes[level] = next;
 		path->slots[level] = 0;
 		if (!path->skip_locking)
 			path->locks[level] = 1;
+
 		if (!level)
 			break;
 
-		btrfs_set_path_blocking(path);
-		if (level == 1 && path->locks[1] && path->reada)
-			reada_for_search(root, path, level, slot, 0);
-		next = read_node_slot(root, next, 0);
+		ret = read_block_for_search(NULL, root, path, &next, level,
+					    0, &key);
+		if (ret == -EAGAIN)
+			goto again;
+
 		if (!path->skip_locking) {
 			btrfs_assert_tree_locked(path->nodes[level]);
-			btrfs_tree_lock(next);
-			btrfs_set_lock_blocking(next);
+			ret = btrfs_try_spin_lock(next);
+			if (!ret) {
+				btrfs_set_path_blocking(path);
+				btrfs_tree_lock(next);
+				if (!force_blocking)
+					btrfs_clear_path_blocking(path, next);
+			}
+			if (force_blocking)
+				btrfs_set_lock_blocking(next);
 		}
 	}
+	ret = 0;
 done:
 	unlock_up(path, 0, 1);
-	return 0;
+	path->leave_spinning = old_spinning;
+	if (!old_spinning)
+		btrfs_set_path_blocking(path);
+
+	return ret;
 }
 
 /*

fs/btrfs/ctree.h

···
 #define BTRFS_FT_MAX		9
 
 /*
- * the key defines the order in the tree, and so it also defines (optimal)
- * block layout.  objectid corresonds to the inode number.  The flags
- * tells us things about the object, and is a kind of stream selector.
- * so for a given inode, keys with flags of 1 might refer to the inode
- * data, flags of 2 may point to file data in the btree and flags == 3
- * may point to extents.
+ * The key defines the order in the tree, and so it also defines (optimal)
+ * block layout.
+ *
+ * objectid corresponds to the inode number.
+ *
+ * type tells us things about the object, and is a kind of stream selector.
+ * so for a given inode, keys with type of 1 might refer to the inode data,
+ * type of 2 may point to file data in the btree and type == 3 may point to
+ * extents.
  *
  * offset is the starting byte offset for this key in the stream.
  *
···
 
 	/*
 	 * starting byte of this partition on the device,
-	 * to allowr for stripe alignment in the future
+	 * to allow for stripe alignment in the future
 	 */
 	__le64 start_offset;
 
···
 	struct rw_semaphore groups_sem;
 };
 
-struct btrfs_free_space {
-	struct rb_node bytes_index;
-	struct rb_node offset_index;
-	u64 offset;
-	u64 bytes;
+/*
+ * free clusters are used to claim free space in relatively large chunks,
+ * allowing us to do less seeky writes.  They are used for all metadata
+ * allocations and data allocations in ssd mode.
+ */
+struct btrfs_free_cluster {
+	spinlock_t lock;
+	spinlock_t refill_lock;
+	struct rb_root root;
+
+	/* largest extent in this cluster */
+	u64 max_size;
+
+	/* first extent starting offset */
+	u64 window_start;
+
+	struct btrfs_block_group_cache *block_group;
+	/*
+	 * when a cluster is allocated from a block group, we put the
+	 * cluster onto a list in the block group so that it can
+	 * be freed before the block group is freed.
+	 */
+	struct list_head block_group_list;
 };
 
 struct btrfs_block_group_cache {
 	struct btrfs_key key;
 	struct btrfs_block_group_item item;
 	spinlock_t lock;
-	struct mutex alloc_mutex;
 	struct mutex cache_mutex;
 	u64 pinned;
 	u64 reserved;
···
 	struct btrfs_space_info *space_info;
 
 	/* free space cache stuff */
+	spinlock_t tree_lock;
 	struct rb_root free_space_bytes;
 	struct rb_root free_space_offset;
 
···
 
 	/* usage count */
 	atomic_t count;
+
+	/* List of struct btrfs_free_clusters for this block group.
+	 * Today it will only have one thing on it, but that may change
+	 */
+	struct list_head cluster_list;
 };
 
 struct btrfs_leaf_ref_tree {
···
 	struct mutex tree_log_mutex;
 	struct mutex transaction_kthread_mutex;
 	struct mutex cleaner_mutex;
-	struct mutex pinned_mutex;
 	struct mutex chunk_mutex;
 	struct mutex drop_mutex;
 	struct mutex volume_mutex;
···
 	spinlock_t delalloc_lock;
 	spinlock_t new_trans_lock;
 	u64 delalloc_bytes;
-	u64 last_alloc;
-	u64 last_data_alloc;
+
+	/* data_alloc_cluster is only used in ssd mode */
+	struct btrfs_free_cluster data_alloc_cluster;
+
+	/* all metadata allocations go through this cluster */
+	struct btrfs_free_cluster meta_alloc_cluster;
 
 	spinlock_t ref_cache_lock;
 	u64 total_ref_cache_size;
···
 };
 
 /*
-
  * inode items have the data typically returned from stat and store other
  * info about object characteristics.  There is one for every file and dir in
  * the FS
···
 #define BTRFS_EXTENT_CSUM_KEY	128
 
 /*
- * root items point to tree roots.  There are typically in the root
+ * root items point to tree roots.  They are typically in the root
  * tree used by the super block to find all the other trees
  */
 #define BTRFS_ROOT_ITEM_KEY	132
···
 #define BTRFS_MOUNT_SSD			(1 << 3)
 #define BTRFS_MOUNT_DEGRADED		(1 << 4)
 #define BTRFS_MOUNT_COMPRESS		(1 << 5)
+#define BTRFS_MOUNT_NOTREELOG           (1 << 6)
+#define BTRFS_MOUNT_FLUSHONCOMMIT       (1 << 7)
 
 #define btrfs_clear_opt(o, opt)		((o) &= ~BTRFS_MOUNT_##opt)
 #define btrfs_set_opt(o, opt)		((o) |= BTRFS_MOUNT_##opt)
···
 }
 
 /* extent-tree.c */
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 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_init_acl(struct inode *inode, struct inode *dir);
 int btrfs_acl_chmod(struct inode *inode);
 
-/* free-space-cache.c */
-int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-			 u64 bytenr, u64 size);
-int btrfs_add_free_space_lock(struct btrfs_block_group_cache *block_group,
-			      u64 offset, u64 bytes);
-int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
-			    u64 bytenr, u64 size);
-int btrfs_remove_free_space_lock(struct btrfs_block_group_cache *block_group,
-				 u64 offset, u64 bytes);
-void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
-				   *block_group);
-struct btrfs_free_space *btrfs_find_free_space(struct btrfs_block_group_cache
-					       *block_group, u64 offset,
-					       u64 bytes);
-void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
-			   u64 bytes);
-u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
 #endif

fs/btrfs/delayed-ref.c

···
 
 #include <linux/sched.h>
 #include <linux/sort.h>
-#include <linux/ftrace.h>
 #include "ctree.h"
 #include "delayed-ref.h"
 #include "transaction.h"

fs/btrfs/disk-io.c

···
 #include "locking.h"
 #include "ref-cache.h"
 #include "tree-log.h"
+#include "free-space-cache.h"
 
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
···
 
 	ret = extent_range_uptodate(io_tree, start + length,
 				    start + buf_len - 1);
-	if (ret == 1)
-		return ret;
 	return ret;
 }
 
···
 	mutex_init(&fs_info->ordered_operations_mutex);
 	mutex_init(&fs_info->tree_log_mutex);
 	mutex_init(&fs_info->drop_mutex);
-	mutex_init(&fs_info->pinned_mutex);
 	mutex_init(&fs_info->chunk_mutex);
 	mutex_init(&fs_info->transaction_kthread_mutex);
 	mutex_init(&fs_info->cleaner_mutex);
 	mutex_init(&fs_info->volume_mutex);
 	mutex_init(&fs_info->tree_reloc_mutex);
+
+	btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
+	btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
+
 	init_waitqueue_head(&fs_info->transaction_throttle);
 	init_waitqueue_head(&fs_info->transaction_wait);
 	init_waitqueue_head(&fs_info->async_submit_wait);

fs/btrfs/extent-tree.c

···
 #include "volumes.h"
 #include "locking.h"
 #include "ref-cache.h"
+#include "free-space-cache.h"
 
 #define PENDING_EXTENT_INSERT 0
 #define PENDING_EXTENT_DELETE 1
···
 	u64 extent_start, extent_end, size;
 	int ret;
 
-	mutex_lock(&info->pinned_mutex);
 	while (start < end) {
 		ret = find_first_extent_bit(&info->pinned_extents, start,
 					    &extent_start, &extent_end,
···
 		ret = btrfs_add_free_space(block_group, start, size);
 		BUG_ON(ret);
 	}
-	mutex_unlock(&info->pinned_mutex);
 
 	return 0;
 }
···
 			   block_group->key.objectid +
 			   block_group->key.offset);
 
-	remove_sb_from_cache(root, block_group);
 	block_group->cached = 1;
+	remove_sb_from_cache(root, block_group);
 	ret = 0;
 err:
 	btrfs_free_path(path);
···
 	return cache;
 }
 
-static inline void put_block_group(struct btrfs_block_group_cache *cache)
+void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
 {
 	if (atomic_dec_and_test(&cache->count))
 		kfree(cache);
···
 			    div_factor(cache->key.offset, factor)) {
 				group_start = cache->key.objectid;
 				spin_unlock(&cache->lock);
-				put_block_group(cache);
+				btrfs_put_block_group(cache);
 				goto found;
 			}
 		}
 		spin_unlock(&cache->lock);
-		put_block_group(cache);
+		btrfs_put_block_group(cache);
 		cond_resched();
 	}
 	if (!wrapped) {
···
 	if (!block_group || block_group->ro)
 		readonly = 1;
 	if (block_group)
-		put_block_group(block_group);
+		btrfs_put_block_group(block_group);
 	return readonly;
 }
 
···
 				WARN_ON(ret);
 			}
 		}
-		put_block_group(cache);
+		btrfs_put_block_group(cache);
 		total -= num_bytes;
 		bytenr += num_bytes;
 	}
···
 		return 0;
 
 	bytenr = cache->key.objectid;
-	put_block_group(cache);
+	btrfs_put_block_group(cache);
 
 	return bytenr;
 }
···
 	struct btrfs_block_group_cache *cache;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
-	WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
 	if (pin) {
 		set_extent_dirty(&fs_info->pinned_extents,
 				bytenr, bytenr + num - 1, GFP_NOFS);
···
 		clear_extent_dirty(&fs_info->pinned_extents,
 				bytenr, bytenr + num - 1, GFP_NOFS);
 	}
-	mutex_unlock(&root->fs_info->pinned_mutex);
 
 	while (num > 0) {
 		cache = btrfs_lookup_block_group(fs_info, bytenr);
···
 			if (cache->cached)
 				btrfs_add_free_space(cache, bytenr, len);
 		}
-		put_block_group(cache);
+		btrfs_put_block_group(cache);
 		bytenr += len;
 		num -= len;
 	}
···
 		}
 		spin_unlock(&cache->lock);
 		spin_unlock(&cache->space_info->lock);
-		put_block_group(cache);
+		btrfs_put_block_group(cache);
 		bytenr += len;
 		num -= len;
 	}
···
 	struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
 	int ret;
 
-	mutex_lock(&root->fs_info->pinned_mutex);
 	while (1) {
 		ret = find_first_extent_bit(pinned_extents, last,
 					    &start, &end, EXTENT_DIRTY);
···
 		set_extent_dirty(copy, start, end, GFP_NOFS);
 		last = end + 1;
 	}
-	mutex_unlock(&root->fs_info->pinned_mutex);
 	return 0;
 }
 
···
 	int ret;
 
 	while (1) {
-		mutex_lock(&root->fs_info->pinned_mutex);
 		ret = find_first_extent_bit(unpin, 0, &start, &end,
 					    EXTENT_DIRTY);
 		if (ret)
···
 
 		cond_resched();
 	}
-	mutex_unlock(&root->fs_info->pinned_mutex);
 	return ret;
 }
 
···
 	free_extent_buffer(buf);
 pinit:
 	btrfs_set_path_blocking(path);
-	mutex_lock(&root->fs_info->pinned_mutex);
 	/* unlocks the pinned mutex */
 	btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
 
···
 	 */
 	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID &&
 	    owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
-		mutex_lock(&root->fs_info->pinned_mutex);
-
 		/* unlocks the pinned mutex */
 		btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
 		update_reserved_extents(root, bytenr, num_bytes, 0);
···
 {
 	int ret = 0;
 	struct btrfs_root *root = orig_root->fs_info->extent_root;
-	u64 total_needed = num_bytes;
-	u64 *last_ptr = NULL;
-	u64 last_wanted = 0;
+	struct btrfs_free_cluster *last_ptr = NULL;
 	struct btrfs_block_group_cache *block_group = NULL;
-	int chunk_alloc_done = 0;
 	int empty_cluster = 2 * 1024 * 1024;
 	int allowed_chunk_alloc = 0;
-	struct list_head *head = NULL, *cur = NULL;
-	int loop = 0;
-	int extra_loop = 0;
 	struct btrfs_space_info *space_info;
+	int last_ptr_loop = 0;
+	int loop = 0;
 
 	WARN_ON(num_bytes < root->sectorsize);
 	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
 	ins->objectid = 0;
 	ins->offset = 0;
 
+	space_info = __find_space_info(root->fs_info, data);
+
 	if (orig_root->ref_cows || empty_size)
 		allowed_chunk_alloc = 1;
 
 	if (data & BTRFS_BLOCK_GROUP_METADATA) {
-		last_ptr = &root->fs_info->last_alloc;
+		last_ptr = &root->fs_info->meta_alloc_cluster;
 		if (!btrfs_test_opt(root, SSD))
 			empty_cluster = 64 * 1024;
 	}
 
-	if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
-		last_ptr = &root->fs_info->last_data_alloc;
+	if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
+		last_ptr = &root->fs_info->data_alloc_cluster;
+	}
 
 	if (last_ptr) {
-		if (*last_ptr) {
-			hint_byte = *last_ptr;
-			last_wanted = *last_ptr;
-		} else
-			empty_size += empty_cluster;
-	} else {
-		empty_cluster = 0;
+		spin_lock(&last_ptr->lock);
+		if (last_ptr->block_group)
+			hint_byte = last_ptr->window_start;
+		spin_unlock(&last_ptr->lock);
 	}
+
 	search_start = max(search_start, first_logical_byte(root, 0));
 	search_start = max(search_start, hint_byte);
 
-	if (last_wanted && search_start != last_wanted) {
-		last_wanted = 0;
-		empty_size += empty_cluster;
+	if (!last_ptr) {
+		empty_cluster = 0;
+		loop = 1;
 	}
 
-	total_needed += empty_size;
-	block_group = btrfs_lookup_block_group(root->fs_info, search_start);
-	if (!block_group)
-		block_group = btrfs_lookup_first_block_group(root->fs_info,
-							     search_start);
-	space_info = __find_space_info(root->fs_info, data);
+	if (search_start == hint_byte) {
+		block_group = btrfs_lookup_block_group(root->fs_info,
+						       search_start);
+		if (block_group && block_group_bits(block_group, data)) {
+			down_read(&space_info->groups_sem);
+			goto have_block_group;
+		} else if (block_group) {
+			btrfs_put_block_group(block_group);
+		}
+	}
 
+search:
 	down_read(&space_info->groups_sem);
-	while (1) {
-		struct btrfs_free_space *free_space;
-		/*
-		 * the only way this happens if our hint points to a block
-		 * group thats not of the proper type, while looping this
-		 * should never happen
-		 */
-		if (empty_size)
-			extra_loop = 1;
+	list_for_each_entry(block_group, &space_info->block_groups, list) {
+		u64 offset;
 
-		if (!block_group)
-			goto new_group_no_lock;
+		atomic_inc(&block_group->count);
+		search_start = block_group->key.objectid;
 
+have_block_group:
 		if (unlikely(!block_group->cached)) {
 			mutex_lock(&block_group->cache_mutex);
 			ret = cache_block_group(root, block_group);
 			mutex_unlock(&block_group->cache_mutex);
-			if (ret)
+			if (ret) {
+				btrfs_put_block_group(block_group);
 				break;
+			}
 		}
-
-		mutex_lock(&block_group->alloc_mutex);
-		if (unlikely(!block_group_bits(block_group, data)))
-			goto new_group;
 
 		if (unlikely(block_group->ro))
-			goto new_group;
+			goto loop;
 
-		free_space = btrfs_find_free_space(block_group, search_start,
-						   total_needed);
-		if (free_space) {
-			u64 start = block_group->key.objectid;
-			u64 end = block_group->key.objectid +
-				block_group->key.offset;
-
-			search_start = stripe_align(root, free_space->offset);
-
-			/* move on to the next group */
-			if (search_start + num_bytes >= search_end)
-				goto new_group;
-
-			/* move on to the next group */
-			if (search_start + num_bytes > end)
-				goto new_group;
-
-			if (last_wanted && search_start != last_wanted) {
-				total_needed += empty_cluster;
-				empty_size += empty_cluster;
-				last_wanted = 0;
-				/*
-				 * if search_start is still in this block group
-				 * then we just re-search this block group
-				 */
-				if (search_start >= start &&
-				    search_start < end) {
-					mutex_unlock(&block_group->alloc_mutex);
-					continue;
-				}
-
-				/* else we go to the next block group */
-				goto new_group;
-			}
-
-			if (exclude_nr > 0 &&
-			    (search_start + num_bytes > exclude_start &&
-			     search_start < exclude_start + exclude_nr)) {
-				search_start = exclude_start + exclude_nr;
-				/*
-				 * if search_start is still in this block group
-				 * then we just re-search this block group
-				 */
-				if (search_start >= start &&
-				    search_start < end) {
-					mutex_unlock(&block_group->alloc_mutex);
-					last_wanted = 0;
-					continue;
-				}
-
-				/* else we go to the next block group */
-				goto new_group;
-			}
-
-			ins->objectid = search_start;
-			ins->offset = num_bytes;
-
-			btrfs_remove_free_space_lock(block_group, search_start,
-						     num_bytes);
-			/* we are all good, lets return */
-			mutex_unlock(&block_group->alloc_mutex);
-			break;
-		}
-new_group:
-		mutex_unlock(&block_group->alloc_mutex);
-		put_block_group(block_group);
-		block_group = NULL;
-new_group_no_lock:
-		/* don't try to compare new allocations against the
-		 * last allocation any more
-		 */
-		last_wanted = 0;
-
-		/*
-		 * Here's how this works.
-		 * loop == 0: we were searching a block group via a hint
-		 *		and didn't find anything, so we start at
-		 *		the head of the block groups and keep searching
-		 * loop == 1: we're searching through all of the block groups
-		 *		if we hit the head again we have searched
-		 *		all of the block groups for this space and we
-		 *		need to try and allocate, if we cant error out.
-		 * loop == 2: we allocated more space and are looping through
-		 *		all of the block groups again.
-		 */
-		if (loop == 0) {
-			head = &space_info->block_groups;
-			cur = head->next;
-			loop++;
-		} else if (loop == 1 && cur == head) {
-			int keep_going;
-
-			/* at this point we give up on the empty_size
-			 * allocations and just try to allocate the min
-			 * space.
-			 *
-			 * The extra_loop field was set if an empty_size
-			 * allocation was attempted above, and if this
-			 * is try we need to try the loop again without
-			 * the additional empty_size.
+		if (last_ptr) {
+			/*
+			 * the refill lock keeps out other
+			 * people trying to start a new cluster
 			 */
-			total_needed -= empty_size;
-			empty_size = 0;
-			keep_going = extra_loop;
-			loop++;
+			spin_lock(&last_ptr->refill_lock);
+			offset = btrfs_alloc_from_cluster(block_group, last_ptr,
+						 num_bytes, search_start);
+			if (offset) {
+				/* we have a block, we're done */
+				spin_unlock(&last_ptr->refill_lock);
+				goto checks;
+			}
 
-			if (allowed_chunk_alloc && !chunk_alloc_done) {
-				up_read(&space_info->groups_sem);
-				ret = do_chunk_alloc(trans, root, num_bytes +
-						     2 * 1024 * 1024, data, 1);
-				down_read(&space_info->groups_sem);
-				if (ret < 0)
-					goto loop_check;
-				head = &space_info->block_groups;
+			spin_lock(&last_ptr->lock);
+			/*
+			 * whoops, this cluster doesn't actually point to
+			 * this block group.  Get a ref on the block
+			 * group is does point to and try again
+			 */
+			if (!last_ptr_loop && last_ptr->block_group &&
+			    last_ptr->block_group != block_group) {
+
+				btrfs_put_block_group(block_group);
+				block_group = last_ptr->block_group;
+				atomic_inc(&block_group->count);
+				spin_unlock(&last_ptr->lock);
+				spin_unlock(&last_ptr->refill_lock);
+
+				last_ptr_loop = 1;
+				search_start = block_group->key.objectid;
+				goto have_block_group;
+			}
+			spin_unlock(&last_ptr->lock);
+
+			/*
+			 * this cluster didn't work out, free it and
+			 * start over
+			 */
+			btrfs_return_cluster_to_free_space(NULL, last_ptr);
+
+			last_ptr_loop = 0;
+
+			/* allocate a cluster in this block group */
+			ret = btrfs_find_space_cluster(trans,
+					       block_group, last_ptr,
+					       offset, num_bytes,
+					       empty_cluster + empty_size);
+			if (ret == 0) {
 				/*
-				 * we've allocated a new chunk, keep
-				 * trying
+				 * now pull our allocation out of this
+				 * cluster
 				 */
-				keep_going = 1;
-				chunk_alloc_done = 1;
-			} else if (!allowed_chunk_alloc) {
-				space_info->force_alloc = 1;
+				offset = btrfs_alloc_from_cluster(block_group,
+						  last_ptr, num_bytes,
+						  search_start);
+				if (offset) {
+					/* we found one, proceed */
+					spin_unlock(&last_ptr->refill_lock);
+					goto checks;
+				}
 			}
-loop_check:
-			if (keep_going) {
-				cur = head->next;
-				extra_loop = 0;
-			} else {
-				break;
+			/*
+			 * at this point we either didn't find a cluster
+			 * or we weren't able to allocate a block from our
+			 * cluster.  Free the cluster we've been trying
+			 * to use, and go to the next block group
+			 */
+			if (loop < 2) {
+				btrfs_return_cluster_to_free_space(NULL,
+								   last_ptr);
+				spin_unlock(&last_ptr->refill_lock);
+				goto loop;
 			}
-		} else if (cur == head) {
-			break;
+			spin_unlock(&last_ptr->refill_lock);
 		}
 
-		block_group = list_entry(cur, struct btrfs_block_group_cache,
-					 list);
-		atomic_inc(&block_group->count);
+		offset = btrfs_find_space_for_alloc(block_group, search_start,
+						    num_bytes, empty_size);
+		if (!offset)
+			goto loop;
+checks:
+		search_start = stripe_align(root, offset);
 
-		search_start = block_group->key.objectid;
-		cur = cur->next;
+		/* move on to the next group */
+		if (search_start + num_bytes >= search_end) {
+			btrfs_add_free_space(block_group, offset, num_bytes);
+			goto loop;
+		}
+
+		/* move on to the next group */
+		if (search_start + num_bytes >
+		    block_group->key.objectid + block_group->key.offset) {
+			btrfs_add_free_space(block_group, offset, num_bytes);
+			goto loop;
+		}
+
+		if (exclude_nr > 0 &&
+		    (search_start + num_bytes > exclude_start &&
+		     search_start < exclude_start + exclude_nr)) {
+			search_start = exclude_start + exclude_nr;
+
+			btrfs_add_free_space(block_group, offset, num_bytes);
+			/*
+			 * if search_start is still in this block group
+			 * then we just re-search this block group
+			 */
+			if (search_start >= block_group->key.objectid &&
+			    search_start < (block_group->key.objectid +
+					    block_group->key.offset))
+				goto have_block_group;
+			goto loop;
+		}
+
+		ins->objectid = search_start;
+		ins->offset = num_bytes;
+
+		if (offset < search_start)
+			btrfs_add_free_space(block_group, offset,
+					     search_start - offset);
+		BUG_ON(offset > search_start);
+
+		/* we are all good, lets return */
+		break;
+loop:
+		btrfs_put_block_group(block_group);
+	}
+	up_read(&space_info->groups_sem);
+
+	/* loop == 0, try to find a clustered alloc in every block group
+	 * loop == 1, try again after forcing a chunk allocation
+	 * loop == 2, set empty_size and empty_cluster to 0 and try again
+	 */
+	if (!ins->objectid && loop < 3 &&
+	    (empty_size || empty_cluster || allowed_chunk_alloc)) {
+		if (loop >= 2) {
+			empty_size = 0;
+			empty_cluster = 0;
+		}
+
+		if (allowed_chunk_alloc) {
+			ret = do_chunk_alloc(trans, root, num_bytes +
+					     2 * 1024 * 1024, data, 1);
+			allowed_chunk_alloc = 0;
+		} else {
+			space_info->force_alloc = 1;
+		}
+
+		if (loop < 3) {
+			loop++;
+			goto search;
+		}
+		ret = -ENOSPC;
+	} else if (!ins->objectid) {
+		ret = -ENOSPC;
 	}
 
 	/* we found what we needed */
···
 		if (!(data & BTRFS_BLOCK_GROUP_DATA))
 			trans->block_group = block_group->key.objectid;
 
-		if (last_ptr)
-			*last_ptr = ins->objectid + ins->offset;
+		btrfs_put_block_group(block_group);
 		ret = 0;
-	} else if (!ret) {
-		printk(KERN_ERR "btrfs searching for %llu bytes, "
-		       "num_bytes %llu, loop %d, allowed_alloc %d\n",
-		       (unsigned long long)total_needed,
-		       (unsigned long long)num_bytes,
-		       loop, allowed_chunk_alloc);
-		ret = -ENOSPC;
 	}
-	if (block_group)
-		put_block_group(block_group);
 
-	up_read(&space_info->groups_sem);
 	return ret;
 }
 
···
 	ret = btrfs_discard_extent(root, start, len);
 
 	btrfs_add_free_space(cache, start, len);
-	put_block_group(cache);
+	btrfs_put_block_group(cache);
 	update_reserved_extents(root, start, len, 0);
 
 	return ret;
···
 	ret = btrfs_remove_free_space(block_group, ins->objectid,
 				      ins->offset);
 	BUG_ON(ret);
-	put_block_group(block_group);
+	btrfs_put_block_group(block_group);
 	ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
 					    ref_generation, owner, ins, 1);
 	return ret;
···
 	WARN_ON(block_group->reserved > 0);
 	WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
 	spin_unlock(&block_group->lock);
-	put_block_group(block_group);
+	btrfs_put_block_group(block_group);
 	ret = 0;
 out:
 	btrfs_free_path(path);
···
 
 		atomic_set(&cache->count, 1);
 		spin_lock_init(&cache->lock);
-		mutex_init(&cache->alloc_mutex);
+		spin_lock_init(&cache->tree_lock);
 		mutex_init(&cache->cache_mutex);
 		INIT_LIST_HEAD(&cache->list);
+		INIT_LIST_HEAD(&cache->cluster_list);
 		read_extent_buffer(leaf, &cache->item,
 				   btrfs_item_ptr_offset(leaf, path->slots[0]),
 				   sizeof(cache->item));
···
 	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
 	atomic_set(&cache->count, 1);
 	spin_lock_init(&cache->lock);
-	mutex_init(&cache->alloc_mutex);
+	spin_lock_init(&cache->tree_lock);
 	mutex_init(&cache->cache_mutex);
 	INIT_LIST_HEAD(&cache->list);
+	INIT_LIST_HEAD(&cache->cluster_list);
 
 	btrfs_set_block_group_used(&cache->item, bytes_used);
 	btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
···
 	spin_unlock(&block_group->space_info->lock);
 	block_group->space_info->full = 0;
 
-	put_block_group(block_group);
-	put_block_group(block_group);
+	btrfs_put_block_group(block_group);
+	btrfs_put_block_group(block_group);
 
 	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 	if (ret > 0)

fs/btrfs/extent_io.c

···
 		disko = 0;
 		flags = 0;
 
-		switch (em->block_start) {
-		case EXTENT_MAP_LAST_BYTE:
+		if (em->block_start == EXTENT_MAP_LAST_BYTE) {
 			end = 1;
 			flags |= FIEMAP_EXTENT_LAST;
-			break;
-		case EXTENT_MAP_HOLE:
+		} else if (em->block_start == EXTENT_MAP_HOLE) {
 			flags |= FIEMAP_EXTENT_UNWRITTEN;
-			break;
-		case EXTENT_MAP_INLINE:
+		} else if (em->block_start == EXTENT_MAP_INLINE) {
 			flags |= (FIEMAP_EXTENT_DATA_INLINE |
 				  FIEMAP_EXTENT_NOT_ALIGNED);
-			break;
-		case EXTENT_MAP_DELALLOC:
+		} else if (em->block_start == EXTENT_MAP_DELALLOC) {
 			flags |= (FIEMAP_EXTENT_DELALLOC |
 				  FIEMAP_EXTENT_UNKNOWN);
-			break;
-		default:
+		} else {
 			disko = em->block_start;
-			break;
 		}
 		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
 			flags |= FIEMAP_EXTENT_ENCODED;

fs/btrfs/extent_map.c

···
 	rb = tree_insert(&tree->map, em->start, &em->rb_node);
 	if (rb) {
 		ret = -EEXIST;
-		free_extent_map(merge);
 		goto out;
 	}
 	atomic_inc(&em->refs);

fs/btrfs/free-space-cache.c

···
 
 #include <linux/sched.h>
 #include "ctree.h"
+#include "free-space-cache.h"
+#include "transaction.h"
+
+struct btrfs_free_space {
+	struct rb_node bytes_index;
+	struct rb_node offset_index;
+	u64 offset;
+	u64 bytes;
+};
 
 static int tree_insert_offset(struct rb_root *root, u64 offset,
 			      struct rb_node *node)
···
 }
 
 /*
- * searches the tree for the given offset.  If contains is set we will return
- * the free space that contains the given offset.  If contains is not set we
- * will return the free space that starts at or after the given offset and is
- * at least bytes long.
+ * searches the tree for the given offset.
+ *
+ * fuzzy == 1: this is used for allocations where we are given a hint of where
+ * to look for free space.  Because the hint may not be completely on an offset
+ * mark, or the hint may no longer point to free space we need to fudge our
+ * results a bit.  So we look for free space starting at or after offset with at
+ * least bytes size.  We prefer to find as close to the given offset as we can.
+ * Also if the offset is within a free space range, then we will return the free
+ * space that contains the given offset, which means we can return a free space
+ * chunk with an offset before the provided offset.
+ *
+ * fuzzy == 0: this is just a normal tree search.  Give us the free space that
+ * starts at the given offset which is at least bytes size, and if its not there
+ * return NULL.
  */
 static struct btrfs_free_space *tree_search_offset(struct rb_root *root,
 						   u64 offset, u64 bytes,
-						   int contains)
+						   int fuzzy)
 {
 	struct rb_node *n = root->rb_node;
 	struct btrfs_free_space *entry, *ret = NULL;
···
 		entry = rb_entry(n, struct btrfs_free_space, offset_index);
 
 		if (offset < entry->offset) {
-			if (!contains &&
+			if (fuzzy &&
 			    (!ret || entry->offset < ret->offset) &&
 			    (bytes <= entry->bytes))
 				ret = entry;
 			n = n->rb_left;
 		} else if (offset > entry->offset) {
-			if ((entry->offset + entry->bytes - 1) >= offset &&
+			if (fuzzy &&
+			    (entry->offset + entry->bytes - 1) >= offset &&
 			    bytes <= entry->bytes) {
 				ret = entry;
 				break;
···
 	int ret = 0;
 
 
+	BUG_ON(!info->bytes);
 	ret = tree_insert_offset(&block_group->free_space_offset, info->offset,
 				 &info->offset_index);
 	if (ret)
···
 	return ret;
 }
 
-static int __btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-				  u64 offset, u64 bytes)
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 offset, u64 bytes)
 {
 	struct btrfs_free_space *right_info;
 	struct btrfs_free_space *left_info;
 	struct btrfs_free_space *info = NULL;
-	struct btrfs_free_space *alloc_info;
 	int ret = 0;
 
-	alloc_info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
-	if (!alloc_info)
+	info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+	if (!info)
 		return -ENOMEM;
+
+	info->offset = offset;
+	info->bytes = bytes;
+
+	spin_lock(&block_group->tree_lock);
 
 	/*
 	 * first we want to see if there is free space adjacent to the range we
···
 	 * cover the entire range
 	 */
 	right_info = tree_search_offset(&block_group->free_space_offset,
-					offset+bytes, 0, 1);
+					offset+bytes, 0, 0);
 	left_info = tree_search_offset(&block_group->free_space_offset,
 				       offset-1, 0, 1);
 
-	if (right_info && right_info->offset == offset+bytes) {
+	if (right_info) {
 		unlink_free_space(block_group, right_info);
-		info = right_info;
-		info->offset = offset;
-		info->bytes += bytes;
-	} else if (right_info && right_info->offset != offset+bytes) {
-		printk(KERN_ERR "btrfs adding space in the middle of an "
-		       "existing free space area. existing: "
-		       "offset=%llu, bytes=%llu. new: offset=%llu, "
-		       "bytes=%llu\n", (unsigned long long)right_info->offset,
-		       (unsigned long long)right_info->bytes,
-		       (unsigned long long)offset,
-		       (unsigned long long)bytes);
-		BUG();
+		info->bytes += right_info->bytes;
+		kfree(right_info);
 	}
 
-	if (left_info) {
+	if (left_info && left_info->offset + left_info->bytes == offset) {
 		unlink_free_space(block_group, left_info);
-
-		if (unlikely((left_info->offset + left_info->bytes) !=
-			     offset)) {
-			printk(KERN_ERR "btrfs free space to the left "
-			       "of new free space isn't "
-			       "quite right. existing: offset=%llu, "
-			       "bytes=%llu. new: offset=%llu, bytes=%llu\n",
-			       (unsigned long long)left_info->offset,
-			       (unsigned long long)left_info->bytes,
-			       (unsigned long long)offset,
-			       (unsigned long long)bytes);
-			BUG();
-		}
-
-		if (info) {
-			info->offset = left_info->offset;
-			info->bytes += left_info->bytes;
-			kfree(left_info);
-		} else {
-			info = left_info;
-			info->bytes += bytes;
-		}
+		info->offset = left_info->offset;
+		info->bytes += left_info->bytes;
+		kfree(left_info);
 	}
-
-	if (info) {
-		ret = link_free_space(block_group, info);
-		if (!ret)
-			info = NULL;
-		goto out;
-	}
-
-	info = alloc_info;
-	alloc_info = NULL;
-	info->offset = offset;
-	info->bytes = bytes;
 
 	ret = link_free_space(block_group, info);
 	if (ret)
 		kfree(info);
-out:
+
+	spin_unlock(&block_group->tree_lock);
+
 	if (ret) {
 		printk(KERN_ERR "btrfs: unable to add free space :%d\n", ret);
-		if (ret == -EEXIST)
-			BUG();
+		BUG_ON(ret == -EEXIST);
 	}
-
-	kfree(alloc_info);
 
 	return ret;
 }
 
-static int
-__btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
-			  u64 offset, u64 bytes)
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+			    u64 offset, u64 bytes)
 {
 	struct btrfs_free_space *info;
 	int ret = 0;
 
+	spin_lock(&block_group->tree_lock);
+
 	info = tree_search_offset(&block_group->free_space_offset, offset, 0,
 				  1);
-
 	if (info && info->offset == offset) {
 		if (info->bytes < bytes) {
 			printk(KERN_ERR "Found free space at %llu, size %llu,"
···
 			       (unsigned long long)bytes);
 			WARN_ON(1);
 			ret = -EINVAL;
+			spin_unlock(&block_group->tree_lock);
 			goto out;
 		}
 		unlink_free_space(block_group, info);
 
 		if (info->bytes == bytes) {
 			kfree(info);
+			spin_unlock(&block_group->tree_lock);
 			goto out;
 		}
 
···
 		info->bytes -= bytes;
 
 		ret = link_free_space(block_group, info);
+		spin_unlock(&block_group->tree_lock);
 		BUG_ON(ret);
 	} else if (info && info->offset < offset &&
 		   info->offset + info->bytes >= offset + bytes) {
···
 			 */
 			kfree(info);
 		}
-
+		spin_unlock(&block_group->tree_lock);
 		/* step two, insert a new info struct to cover anything
 		 * before the hole
 		 */
-		ret = __btrfs_add_free_space(block_group, old_start,
-					     offset - old_start);
+		ret = btrfs_add_free_space(block_group, old_start,
+					   offset - old_start);
 		BUG_ON(ret);
 	} else {
+		spin_unlock(&block_group->tree_lock);
+		if (!info) {
+			printk(KERN_ERR "couldn't find space %llu to free\n",
+			       (unsigned long long)offset);
+			printk(KERN_ERR "cached is %d, offset %llu bytes %llu\n",
+			       block_group->cached, block_group->key.objectid,
+			       block_group->key.offset);
+			btrfs_dump_free_space(block_group, bytes);
+		} else if (info) {
+			printk(KERN_ERR "hmm, found offset=%llu bytes=%llu, "
+			       "but wanted offset=%llu bytes=%llu\n",
+			       info->offset, info->bytes, offset, bytes);
+		}
 		WARN_ON(1);
 	}
 out:
-	return ret;
-}
-
-int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-			 u64 offset, u64 bytes)
-{
-	int ret;
-	struct btrfs_free_space *sp;
-
-	mutex_lock(&block_group->alloc_mutex);
-	ret = __btrfs_add_free_space(block_group, offset, bytes);
-	sp = tree_search_offset(&block_group->free_space_offset, offset, 0, 1);
-	BUG_ON(!sp);
-	mutex_unlock(&block_group->alloc_mutex);
-
-	return ret;
-}
-
-int btrfs_add_free_space_lock(struct btrfs_block_group_cache *block_group,
-			      u64 offset, u64 bytes)
-{
-	int ret;
-	struct btrfs_free_space *sp;
-
-	ret = __btrfs_add_free_space(block_group, offset, bytes);
-	sp = tree_search_offset(&block_group->free_space_offset, offset, 0, 1);
-	BUG_ON(!sp);
-
-	return ret;
-}
-
-int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
-			    u64 offset, u64 bytes)
-{
-	int ret = 0;
-
-	mutex_lock(&block_group->alloc_mutex);
-	ret = __btrfs_remove_free_space(block_group, offset, bytes);
-	mutex_unlock(&block_group->alloc_mutex);
-
-	return ret;
-}
-
-int btrfs_remove_free_space_lock(struct btrfs_block_group_cache *block_group,
-				 u64 offset, u64 bytes)
-{
-	int ret;
-
-	ret = __btrfs_remove_free_space(block_group, offset, bytes);
-
 	return ret;
 }
 
···
 		info = rb_entry(n, struct btrfs_free_space, offset_index);
 		if (info->bytes >= bytes)
 			count++;
+		printk(KERN_ERR "entry offset %llu, bytes %llu\n", info->offset,
+		       info->bytes);
 	}
 	printk(KERN_INFO "%d blocks of free space at or bigger than bytes is"
 	       "\n", count);
···
 	return ret;
 }
 
+/*
+ * for a given cluster, put all of its extents back into the free
+ * space cache.  If the block group passed doesn't match the block group
+ * pointed to by the cluster, someone else raced in and freed the
+ * cluster already.  In that case, we just return without changing anything
+ */
+static int
+__btrfs_return_cluster_to_free_space(
+			     struct btrfs_block_group_cache *block_group,
+			     struct btrfs_free_cluster *cluster)
+{
+	struct btrfs_free_space *entry;
+	struct rb_node *node;
+
+	spin_lock(&cluster->lock);
+	if (cluster->block_group != block_group)
+		goto out;
+
+	cluster->window_start = 0;
+	node = rb_first(&cluster->root);
+	while(node) {
+		entry = rb_entry(node, struct btrfs_free_space, offset_index);
+		node = rb_next(&entry->offset_index);
+		rb_erase(&entry->offset_index, &cluster->root);
+		link_free_space(block_group, entry);
+	}
+	list_del_init(&cluster->block_group_list);
+
+	btrfs_put_block_group(cluster->block_group);
+	cluster->block_group = NULL;
+	cluster->root.rb_node = NULL;
+out:
+	spin_unlock(&cluster->lock);
+	return 0;
+}
+
 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
 {
 	struct btrfs_free_space *info;
 	struct rb_node *node;
+	struct btrfs_free_cluster *cluster;
+	struct btrfs_free_cluster *safe;
 
-	mutex_lock(&block_group->alloc_mutex);
+	spin_lock(&block_group->tree_lock);
+
+	list_for_each_entry_safe(cluster, safe, &block_group->cluster_list,
+				 block_group_list) {
+
+		WARN_ON(cluster->block_group != block_group);
+		__btrfs_return_cluster_to_free_space(block_group, cluster);
+	}
+
 	while ((node = rb_last(&block_group->free_space_bytes)) != NULL) {
 		info = rb_entry(node, struct btrfs_free_space, bytes_index);
 		unlink_free_space(block_group, info);
 		kfree(info);
 		if (need_resched()) {
-			mutex_unlock(&block_group->alloc_mutex);
+			spin_unlock(&block_group->tree_lock);
 			cond_resched();
-			mutex_lock(&block_group->alloc_mutex);
+			spin_lock(&block_group->tree_lock);
 		}
 	}
-	mutex_unlock(&block_group->alloc_mutex);
+	spin_unlock(&block_group->tree_lock);
 }
 
-#if 0
-static struct btrfs_free_space *btrfs_find_free_space_offset(struct
-						      btrfs_block_group_cache
-						      *block_group, u64 offset,
-						      u64 bytes)
+u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
+			       u64 offset, u64 bytes, u64 empty_size)
 {
-	struct btrfs_free_space *ret;
+	struct btrfs_free_space *entry = NULL;
+	u64 ret = 0;
 
-	mutex_lock(&block_group->alloc_mutex);
-	ret = tree_search_offset(&block_group->free_space_offset, offset,
-				 bytes, 0);
-	mutex_unlock(&block_group->alloc_mutex);
+	spin_lock(&block_group->tree_lock);
+	entry = tree_search_offset(&block_group->free_space_offset, offset,
+				   bytes + empty_size, 1);
+	if (!entry)
+		entry = tree_search_bytes(&block_group->free_space_bytes,
+					  offset, bytes + empty_size);
+	if (entry) {
+		unlink_free_space(block_group, entry);
+		ret = entry->offset;
+		entry->offset += bytes;
+		entry->bytes -= bytes;
+
+		if (!entry->bytes)
+			kfree(entry);
+		else
+			link_free_space(block_group, entry);
+	}
+	spin_unlock(&block_group->tree_lock);
 
 	return ret;
 }
 
-static struct btrfs_free_space *btrfs_find_free_space_bytes(struct
-						     btrfs_block_group_cache
-						     *block_group, u64 offset,
-						     u64 bytes)
+/*
+ * given a cluster, put all of its extents back into the free space
+ * cache.  If a block group is passed, this function will only free
+ * a cluster that belongs to the passed block group.
+ *
+ * Otherwise, it'll get a reference on the block group pointed to by the
+ * cluster and remove the cluster from it.
+ */
+int btrfs_return_cluster_to_free_space(
+			       struct btrfs_block_group_cache *block_group,
+			       struct btrfs_free_cluster *cluster)
 {
-	struct btrfs_free_space *ret;
+	int ret;
 
-	mutex_lock(&block_group->alloc_mutex);
+	/* first, get a safe pointer to the block group */
+	spin_lock(&cluster->lock);
+	if (!block_group) {
+		block_group = cluster->block_group;
+		if (!block_group) {
+			spin_unlock(&cluster->lock);
+			return 0;
+		}
+	} else if (cluster->block_group != block_group) {
+		/* someone else has already freed it don't redo their work */
+		spin_unlock(&cluster->lock);
+		return 0;
+	}
+	atomic_inc(&block_group->count);
+	spin_unlock(&cluster->lock);
 
-	ret = tree_search_bytes(&block_group->free_space_bytes, offset, bytes);
-	mutex_unlock(&block_group->alloc_mutex);
+	/* now return any extents the cluster had on it */
+	spin_lock(&block_group->tree_lock);
+	ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
+	spin_unlock(&block_group->tree_lock);
+
+	/* finally drop our ref */
+	btrfs_put_block_group(block_group);
+	return ret;
+}
+
+/*
+ * given a cluster, try to allocate 'bytes' from it, returns 0
+ * if it couldn't find anything suitably large, or a logical disk offset
+ * if things worked out
+ */
+u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
+			     struct btrfs_free_cluster *cluster, u64 bytes,
+			     u64 min_start)
+{
+	struct btrfs_free_space *entry = NULL;
+	struct rb_node *node;
+	u64 ret = 0;
+
+	spin_lock(&cluster->lock);
+	if (bytes > cluster->max_size)
+		goto out;
+
+	if (cluster->block_group != block_group)
+		goto out;
+
+	node = rb_first(&cluster->root);
+	if (!node)
+		goto out;
+
+	entry = rb_entry(node, struct btrfs_free_space, offset_index);
+
+	while(1) {
+		if (entry->bytes < bytes || entry->offset < min_start) {
+			struct rb_node *node;
+
+			node = rb_next(&entry->offset_index);
+			if (!node)
+				break;
+			entry = rb_entry(node, struct btrfs_free_space,
+					 offset_index);
+			continue;
+		}
+		ret = entry->offset;
+
+		entry->offset += bytes;
+		entry->bytes -= bytes;
+
+		if (entry->bytes == 0) {
+			rb_erase(&entry->offset_index, &cluster->root);
+			kfree(entry);
+		}
+		break;
+	}
+out:
+	spin_unlock(&cluster->lock);
+	return ret;
+}
+
+/*
+ * here we try to find a cluster of blocks in a block group.  The goal
+ * is to find at least bytes free and up to empty_size + bytes free.
+ * We might not find them all in one contiguous area.
+ *
+ * returns zero and sets up cluster if things worked out, otherwise
+ * it returns -enospc
+ */
+int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
+			     struct btrfs_block_group_cache *block_group,
+			     struct btrfs_free_cluster *cluster,
+			     u64 offset, u64 bytes, u64 empty_size)
+{
+	struct btrfs_free_space *entry = NULL;
+	struct rb_node *node;
+	struct btrfs_free_space *next;
+	struct btrfs_free_space *last;
+	u64 min_bytes;
+	u64 window_start;
+	u64 window_free;
+	u64 max_extent = 0;
+	int total_retries = 0;
+	int ret;
+
+	/* for metadata, allow allocates with more holes */
+	if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
+		/*
+		 * we want to do larger allocations when we are
+		 * flushing out the delayed refs, it helps prevent
+		 * making more work as we go along.
+		 */
+		if (trans->transaction->delayed_refs.flushing)
+			min_bytes = max(bytes, (bytes + empty_size) >> 1);
+		else
+			min_bytes = max(bytes, (bytes + empty_size) >> 4);
+	} else
+		min_bytes = max(bytes, (bytes + empty_size) >> 2);
+
+	spin_lock(&block_group->tree_lock);
+	spin_lock(&cluster->lock);
+
+	/* someone already found a cluster, hooray */
+	if (cluster->block_group) {
+		ret = 0;
+		goto out;
+	}
+again:
+	min_bytes = min(min_bytes, bytes + empty_size);
+	entry = tree_search_bytes(&block_group->free_space_bytes,
+				  offset, min_bytes);
+	if (!entry) {
+		ret = -ENOSPC;
+		goto out;
+	}
+	window_start = entry->offset;
+	window_free = entry->bytes;
+	last = entry;
+	max_extent = entry->bytes;
+
+	while(1) {
+		/* out window is just right, lets fill it */
+		if (window_free >= bytes + empty_size)
+			break;
+
+		node = rb_next(&last->offset_index);
+		if (!node) {
+			ret = -ENOSPC;
+			goto out;
+		}
+		next = rb_entry(node, struct btrfs_free_space, offset_index);
+
+		/*
+		 * we haven't filled the empty size and the window is
+		 * very large.  reset and try again
+		 */
+		if (next->offset - window_start > (bytes + empty_size) * 2) {
+			entry = next;
+			window_start = entry->offset;
+			window_free = entry->bytes;
+			last = entry;
+			max_extent = 0;
+			total_retries++;
+			if (total_retries % 256 == 0) {
+				if (min_bytes >= (bytes + empty_size)) {
+					ret = -ENOSPC;
+					goto out;
+				}
+				/*
+				 * grow our allocation a bit, we're not having
+				 * much luck
+				 */
+				min_bytes *= 2;
+				goto again;
+			}
+		} else {
+			last = next;
+			window_free += next->bytes;
+			if (entry->bytes > max_extent)
+				max_extent = entry->bytes;
+		}
+	}
+
+	cluster->window_start = entry->offset;
+
+	/*
+	 * now we've found our entries, pull them out of the free space
+	 * cache and put them into the cluster rbtree
+	 *
+	 * The cluster includes an rbtree, but only uses the offset index
+	 * of each free space cache entry.
+	 */
+	while(1) {
+		node = rb_next(&entry->offset_index);
+		unlink_free_space(block_group, entry);
+		ret = tree_insert_offset(&cluster->root, entry->offset,
+					 &entry->offset_index);
+		BUG_ON(ret);
+
+		if (!node || entry == last)
+			break;
+
+		entry = rb_entry(node, struct btrfs_free_space, offset_index);
+	}
+	ret = 0;
+	cluster->max_size = max_extent;
+	atomic_inc(&block_group->count);
+	list_add_tail(&cluster->block_group_list, &block_group->cluster_list);
+	cluster->block_group = block_group;
+out:
+	spin_unlock(&cluster->lock);
+	spin_unlock(&block_group->tree_lock);
 
 	return ret;
 }
-#endif
 
-struct btrfs_free_space *btrfs_find_free_space(struct btrfs_block_group_cache
-					       *block_group, u64 offset,
-					       u64 bytes)
+/*
+ * simple code to zero out a cluster
+ */
+void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
 {
-	struct btrfs_free_space *ret = NULL;
-
-	ret = tree_search_offset(&block_group->free_space_offset, offset,
-				 bytes, 0);
-	if (!ret)
-		ret = tree_search_bytes(&block_group->free_space_bytes,
-					offset, bytes);
-
-	return ret;
+	spin_lock_init(&cluster->lock);
+	spin_lock_init(&cluster->refill_lock);
+	cluster->root.rb_node = NULL;
+	cluster->max_size = 0;
+	INIT_LIST_HEAD(&cluster->block_group_list);
+	cluster->block_group = NULL;
 }
+

fs/btrfs/free-space-cache.h

···
+/*
+ * 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.
+ */
+
+#ifndef __BTRFS_FREE_SPACE_CACHE
+#define __BTRFS_FREE_SPACE_CACHE
+
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+			 u64 bytenr, u64 size);
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+			    u64 bytenr, u64 size);
+void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
+				   *block_group);
+u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
+			       u64 offset, u64 bytes, u64 empty_size);
+void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
+			   u64 bytes);
+u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
+int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
+			     struct btrfs_block_group_cache *block_group,
+			     struct btrfs_free_cluster *cluster,
+			     u64 offset, u64 bytes, u64 empty_size);
+void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
+u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
+			     struct btrfs_free_cluster *cluster, u64 bytes,
+			     u64 min_start);
+int btrfs_return_cluster_to_free_space(
+			       struct btrfs_block_group_cache *block_group,
+			       struct btrfs_free_cluster *cluster);
+#endif

fs/btrfs/inode.c

···
 
 	if (dir) {
 		ret = btrfs_set_inode_index(dir, index);
-		if (ret)
+		if (ret) {
+			iput(inode);
 			return ERR_PTR(ret);
+		}
 	}
 	/*
 	 * index_cnt is ignored for everything but a dir,
···
 	if (dir)
 		BTRFS_I(dir)->index_cnt--;
 	btrfs_free_path(path);
+	iput(inode);
 	return ERR_PTR(ret);
 }
 

fs/btrfs/locking.c

···
 
 /*
  * unfortunately, many of the places that currently set a lock to blocking
- * don't end up blocking for every long, and often they don't block
- * at all.  For a dbench 50 run, if we don't spin one the blocking bit
+ * don't end up blocking for very long, and often they don't block
+ * at all.  For a dbench 50 run, if we don't spin on the blocking bit
  * at all, the context switch rate can jump up to 400,000/sec or more.
  *
  * So, we're still stuck with this crummy spin on the blocking bit,

fs/btrfs/super.c

···
 #include <linux/highmem.h>
 #include <linux/time.h>
 #include <linux/init.h>
+#include <linux/seq_file.h>
 #include <linux/string.h>
 #include <linux/smp_lock.h>
 #include <linux/backing-dev.h>
···
 enum {
 	Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
 	Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
-	Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_compress, Opt_err,
+	Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_compress, Opt_notreelog,
+	Opt_flushoncommit, Opt_err,
 };
 
 static match_table_t tokens = {
···
 	{Opt_compress, "compress"},
 	{Opt_ssd, "ssd"},
 	{Opt_noacl, "noacl"},
+	{Opt_notreelog, "notreelog"},
+	{Opt_flushoncommit, "flushoncommit"},
 	{Opt_err, NULL},
 };
 
···
 			break;
 		case Opt_noacl:
 			root->fs_info->sb->s_flags &= ~MS_POSIXACL;
+			break;
+		case Opt_notreelog:
+			printk(KERN_INFO "btrfs: disabling tree log\n");
+			btrfs_set_opt(info->mount_opt, NOTREELOG);
+			break;
+		case Opt_flushoncommit:
+			printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
+			btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 			break;
 		default:
 			break;
···
 int btrfs_sync_fs(struct super_block *sb, int wait)
 {
 	struct btrfs_trans_handle *trans;
-	struct btrfs_root *root;
+	struct btrfs_root *root = btrfs_sb(sb);
 	int ret;
-	root = btrfs_sb(sb);
 
 	if (sb->s_flags & MS_RDONLY)
 		return 0;
···
 	ret = btrfs_commit_transaction(trans, root);
 	sb->s_dirt = 0;
 	return ret;
+}
+
+static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
+{
+	struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
+	struct btrfs_fs_info *info = root->fs_info;
+
+	if (btrfs_test_opt(root, DEGRADED))
+		seq_puts(seq, ",degraded");
+	if (btrfs_test_opt(root, NODATASUM))
+		seq_puts(seq, ",nodatasum");
+	if (btrfs_test_opt(root, NODATACOW))
+		seq_puts(seq, ",nodatacow");
+	if (btrfs_test_opt(root, NOBARRIER))
+		seq_puts(seq, ",nobarrier");
+	if (info->max_extent != (u64)-1)
+		seq_printf(seq, ",max_extent=%llu", info->max_extent);
+	if (info->max_inline != 8192 * 1024)
+		seq_printf(seq, ",max_inline=%llu", info->max_inline);
+	if (info->alloc_start != 0)
+		seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
+	if (info->thread_pool_size !=  min_t(unsigned long,
+					     num_online_cpus() + 2, 8))
+		seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
+	if (btrfs_test_opt(root, COMPRESS))
+		seq_puts(seq, ",compress");
+	if (btrfs_test_opt(root, SSD))
+		seq_puts(seq, ",ssd");
+	if (btrfs_test_opt(root, NOTREELOG))
+		seq_puts(seq, ",no-treelog");
+	if (btrfs_test_opt(root, FLUSHONCOMMIT))
+		seq_puts(seq, ",flush-on-commit");
+	if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
+		seq_puts(seq, ",noacl");
+	return 0;
 }
 
 static void btrfs_write_super(struct super_block *sb)
···
 	.put_super	= btrfs_put_super,
 	.write_super	= btrfs_write_super,
 	.sync_fs	= btrfs_sync_fs,
-	.show_options	= generic_show_options,
+	.show_options	= btrfs_show_options,
 	.write_inode	= btrfs_write_inode,
 	.dirty_inode	= btrfs_dirty_inode,
 	.alloc_inode	= btrfs_alloc_inode,

fs/btrfs/transaction.c

···
 					     GFP_NOFS);
 		BUG_ON(!cur_trans);
 		root->fs_info->generation++;
-		root->fs_info->last_alloc = 0;
-		root->fs_info->last_data_alloc = 0;
 		cur_trans->num_writers = 1;
 		cur_trans->num_joined = 0;
 		cur_trans->transid = root->fs_info->generation;
···
 	int ret;
 	int should_grow = 0;
 	unsigned long now = get_seconds();
+	int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
 
 	btrfs_run_ordered_operations(root, 0);
 
···
 
 		mutex_unlock(&root->fs_info->trans_mutex);
 
-		if (snap_pending) {
+		if (flush_on_commit || snap_pending) {
+			if (flush_on_commit)
+				btrfs_start_delalloc_inodes(root);
 			ret = btrfs_wait_ordered_extents(root, 1);
 			BUG_ON(ret);
 		}

fs/btrfs/tree-log.c

···
 			      struct extent_buffer *eb,
 			      struct walk_control *wc, u64 gen)
 {
-	if (wc->pin) {
-		mutex_lock(&log->fs_info->pinned_mutex);
+	if (wc->pin)
 		btrfs_update_pinned_extents(log->fs_info->extent_root,
 					    eb->start, eb->len, 1);
-	}
 
 	if (btrfs_buffer_uptodate(eb, gen)) {
 		if (wc->write)
···
 	ret = insert_one_name(trans, root, path, key->objectid, key->offset,
 			      name, name_len, log_type, &log_key);
 
-	if (ret && ret != -ENOENT)
-		BUG();
+	BUG_ON(ret && ret != -ENOENT);
 	goto out;
 }
 
···
 	u64 last_committed = root->fs_info->last_trans_committed;
 
 	sb = inode->i_sb;
+
+	if (btrfs_test_opt(root, NOTREELOG)) {
+		ret = 1;
+		goto end_no_trans;
+	}
 
 	if (root->fs_info->last_trans_log_full_commit >
 	    root->fs_info->last_trans_committed) {

fs/btrfs/volumes.c

···
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
 #include <linux/random.h>
+#include <linux/iocontext.h>
 #include <asm/div64.h>
 #include "compat.h"
 #include "ctree.h"
···
 	int again = 0;
 	unsigned long num_run = 0;
 	unsigned long limit;
+	unsigned long last_waited = 0;
 
-	bdi = device->bdev->bd_inode->i_mapping->backing_dev_info;
+	bdi = blk_get_backing_dev_info(device->bdev);
 	fs_info = device->dev_root->fs_info;
 	limit = btrfs_async_submit_limit(fs_info);
 	limit = limit * 2 / 3;
···
 		if (pending && bdi_write_congested(bdi) && num_run > 16 &&
 		    fs_info->fs_devices->open_devices > 1) {
 			struct bio *old_head;
+			struct io_context *ioc;
 
+			ioc = current->io_context;
+
+			/*
+			 * the main goal here is that we don't want to
+			 * block if we're going to be able to submit
+			 * more requests without blocking.
+			 *
+			 * This code does two great things, it pokes into
+			 * the elevator code from a filesystem _and_
+			 * it makes assumptions about how batching works.
+			 */
+			if (ioc && ioc->nr_batch_requests > 0 &&
+			    time_before(jiffies, ioc->last_waited + HZ/50UL) &&
+			    (last_waited == 0 ||
+			     ioc->last_waited == last_waited)) {
+				/*
+				 * we want to go through our batch of
+				 * requests and stop.  So, we copy out
+				 * the ioc->last_waited time and test
+				 * against it before looping
+				 */
+				last_waited = ioc->last_waited;
+				continue;
+			}
 			spin_lock(&device->io_lock);
 
 			old_head = device->pending_bios;
···
 	if (device->pending_bios)
 		goto loop_lock;
 	spin_unlock(&device->io_lock);
+
+	/*
+	 * IO has already been through a long path to get here.  Checksumming,
+	 * async helper threads, perhaps compression.  We've done a pretty
+	 * good job of collecting a batch of IO and should just unplug
+	 * the device right away.
+	 *
+	 * This will help anyone who is waiting on the IO, they might have
+	 * already unplugged, but managed to do so before the bio they
+	 * cared about found its way down here.
+	 */
+	blk_run_backing_dev(bdi, NULL);
 done:
 	return 0;
 }

fs/btrfs/volumes.h

···
 struct btrfs_fs_devices {
 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
 
-	/* the device with this id has the most recent coyp of the super */
+	/* the device with this id has the most recent copy of the super */
 	u64 latest_devid;
 	u64 latest_trans;
 	u64 num_devices;