Merge remote-tracking branch 'remotes/josef/for-chris' into btrfs-next-stable

16 files changed, 1557 insertions, 1058 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index d9f99a16edd..5a5d325a393 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -103,11 +103,6 @@ struct btrfs_inode {
 	 */
 	u64 delalloc_bytes;
 
-	/* total number of bytes that may be used for this inode for
-	 * delalloc
-	 */
-	u64 reserved_bytes;
-
 	/*
 	 * the size of the file stored in the metadata on disk.  data=ordered
 	 * means the in-memory i_size might be larger than the size on disk
@@ -115,9 +110,6 @@ struct btrfs_inode {
 	 */
 	u64 disk_i_size;
 
-	/* flags field from the on disk inode */
-	u32 flags;
-
 	/*
 	 * if this is a directory then index_cnt is the counter for the index
 	 * number for new files that are created
@@ -132,6 +124,15 @@ struct btrfs_inode {
 	u64 last_unlink_trans;
 
 	/*
+	 * Number of bytes outstanding that are going to need csums.  This is
+	 * used in ENOSPC accounting.
+	 */
+	u64 csum_bytes;
+
+	/* flags field from the on disk inode */
+	u32 flags;
+
+	/*
 	 * Counters to keep track of the number of extent item's we may use due
 	 * to delalloc and such.  outstanding_extents is the number of extent
 	 * items we think we'll end up using, and reserved_extents is the number
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 03912c5c6f4..227620993bc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -30,6 +30,7 @@
 #include <linux/kobject.h>
 #include <trace/events/btrfs.h>
 #include <asm/kmap_types.h>
+#include <linux/pagemap.h>
 #include "extent_io.h"
 #include "extent_map.h"
 #include "async-thread.h"
@@ -772,14 +773,8 @@ struct btrfs_space_info {
 struct btrfs_block_rsv {
 	u64 size;
 	u64 reserved;
-	u64 freed[2];
 	struct btrfs_space_info *space_info;
-	struct list_head list;
 	spinlock_t lock;
-	atomic_t usage;
-	unsigned int priority:8;
-	unsigned int durable:1;
-	unsigned int refill_used:1;
 	unsigned int full:1;
 };
 
@@ -840,10 +835,10 @@ struct btrfs_block_group_cache {
 	spinlock_t lock;
 	u64 pinned;
 	u64 reserved;
-	u64 reserved_pinned;
 	u64 bytes_super;
 	u64 flags;
 	u64 sectorsize;
+	u64 cache_generation;
 	unsigned int ro:1;
 	unsigned int dirty:1;
 	unsigned int iref:1;
@@ -899,6 +894,10 @@ struct btrfs_fs_info {
 	spinlock_t block_group_cache_lock;
 	struct rb_root block_group_cache_tree;
 
+	/* keep track of unallocated space */
+	spinlock_t free_chunk_lock;
+	u64 free_chunk_space;
+
 	struct extent_io_tree freed_extents[2];
 	struct extent_io_tree *pinned_extents;
 
@@ -919,11 +918,6 @@ struct btrfs_fs_info {
 
 	struct btrfs_block_rsv empty_block_rsv;
 
-	/* list of block reservations that cross multiple transactions */
-	struct list_head durable_block_rsv_list;
-
-	struct mutex durable_block_rsv_mutex;
-
 	u64 generation;
 	u64 last_trans_committed;
 
@@ -2129,6 +2123,11 @@ static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
 		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
 }
 
+static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
+{
+	return mapping_gfp_mask(mapping) & ~__GFP_FS;
+}
+
 /* extent-tree.c */
 static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
 						 unsigned num_items)
@@ -2137,6 +2136,17 @@ static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
 		3 * num_items;
 }
 
+/*
+ * Doing a truncate won't result in new nodes or leaves, just what we need for
+ * COW.
+ */
+static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_root *root,
+						 unsigned num_items)
+{
+	return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
+		num_items;
+}
+
 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);
@@ -2196,8 +2206,6 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
 		      u64 root_objectid, u64 owner, u64 offset);
 
 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
-int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-				u64 num_bytes, int reserve, int sinfo);
 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
@@ -2240,25 +2248,20 @@ void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv);
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root);
 void btrfs_free_block_rsv(struct btrfs_root *root,
 			  struct btrfs_block_rsv *rsv);
-void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
-				 struct btrfs_block_rsv *rsv);
-int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root,
+int btrfs_block_rsv_add(struct btrfs_root *root,
 			struct btrfs_block_rsv *block_rsv,
 			u64 num_bytes);
-int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
+int btrfs_block_rsv_check(struct btrfs_root *root,
+			  struct btrfs_block_rsv *block_rsv, int min_factor);
+int btrfs_block_rsv_refill(struct btrfs_root *root,
 			  struct btrfs_block_rsv *block_rsv,
-			  u64 min_reserved, int min_factor);
+			  u64 min_reserved);
 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
 			    struct btrfs_block_rsv *dst_rsv,
 			    u64 num_bytes);
 void btrfs_block_rsv_release(struct btrfs_root *root,
 			     struct btrfs_block_rsv *block_rsv,
 			     u64 num_bytes);
-int btrfs_truncate_reserve_metadata(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
-				    struct btrfs_block_rsv *rsv);
 int btrfs_set_block_group_ro(struct btrfs_root *root,
 			     struct btrfs_block_group_cache *cache);
 int btrfs_set_block_group_rw(struct btrfs_root *root,
@@ -2579,11 +2582,6 @@ int btrfs_update_inode(struct btrfs_trans_handle *trans,
 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
 int btrfs_orphan_cleanup(struct btrfs_root *root);
-void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
-				struct btrfs_pending_snapshot *pending,
-				u64 *bytes_to_reserve);
-void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
-				struct btrfs_pending_snapshot *pending);
 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root);
 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 07b3ac662e1..51372a52116 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1648,6 +1648,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	spin_lock_init(&fs_info->fs_roots_radix_lock);
 	spin_lock_init(&fs_info->delayed_iput_lock);
 	spin_lock_init(&fs_info->defrag_inodes_lock);
+	spin_lock_init(&fs_info->free_chunk_lock);
 	mutex_init(&fs_info->reloc_mutex);
 
 	init_completion(&fs_info->kobj_unregister);
@@ -1665,8 +1666,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_init_block_rsv(&fs_info->trans_block_rsv);
 	btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
 	btrfs_init_block_rsv(&fs_info->empty_block_rsv);
-	INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
-	mutex_init(&fs_info->durable_block_rsv_mutex);
 	atomic_set(&fs_info->nr_async_submits, 0);
 	atomic_set(&fs_info->async_delalloc_pages, 0);
 	atomic_set(&fs_info->async_submit_draining, 0);
@@ -1677,6 +1676,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	fs_info->metadata_ratio = 0;
 	fs_info->defrag_inodes = RB_ROOT;
 	fs_info->trans_no_join = 0;
+	fs_info->free_chunk_space = 0;
 
 	fs_info->thread_pool_size = min_t(unsigned long,
 					  num_online_cpus() + 2, 8);
@@ -2545,8 +2545,6 @@ int close_ctree(struct btrfs_root *root)
 	/* clear out the rbtree of defraggable inodes */
 	btrfs_run_defrag_inodes(root->fs_info);
 
-	btrfs_put_block_group_cache(fs_info);
-
 	/*
 	 * Here come 2 situations when btrfs is broken to flip readonly:
 	 *
@@ -2572,6 +2570,8 @@ int close_ctree(struct btrfs_root *root)
 			printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
 	}
 
+	btrfs_put_block_group_cache(fs_info);
+
 	kthread_stop(root->fs_info->transaction_kthread);
 	kthread_stop(root->fs_info->cleaner_kthread);
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f5be06a2462..4eb7d2ba38f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -52,6 +52,21 @@ enum {
 	CHUNK_ALLOC_LIMITED = 2,
 };
 
+/*
+ * Control how reservations are dealt with.
+ *
+ * RESERVE_FREE - freeing a reservation.
+ * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
+ *   ENOSPC accounting
+ * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
+ *   bytes_may_use as the ENOSPC accounting is done elsewhere
+ */
+enum {
+	RESERVE_FREE = 0,
+	RESERVE_ALLOC = 1,
+	RESERVE_ALLOC_NO_ACCOUNT = 2,
+};
+
 static int update_block_group(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      u64 bytenr, u64 num_bytes, int alloc);
@@ -81,6 +96,8 @@ static int find_next_key(struct btrfs_path *path, int level,
 			 struct btrfs_key *key);
 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
 			    int dump_block_groups);
+static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+				       u64 num_bytes, int reserve);
 
 static noinline int
 block_group_cache_done(struct btrfs_block_group_cache *cache)
@@ -104,7 +121,6 @@ void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
 	if (atomic_dec_and_test(&cache->count)) {
 		WARN_ON(cache->pinned > 0);
 		WARN_ON(cache->reserved > 0);
-		WARN_ON(cache->reserved_pinned > 0);
 		kfree(cache->free_space_ctl);
 		kfree(cache);
 	}
@@ -465,7 +481,8 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 	 * we likely hold important locks.
 	 */
 	if (trans && (!trans->transaction->in_commit) &&
-	    (root && root != root->fs_info->tree_root)) {
+	    (root && root != root->fs_info->tree_root) &&
+	    btrfs_test_opt(root, SPACE_CACHE)) {
 		spin_lock(&cache->lock);
 		if (cache->cached != BTRFS_CACHE_NO) {
 			spin_unlock(&cache->lock);
@@ -2700,6 +2717,13 @@ again:
 		goto again;
 	}
 
+	/* We've already setup this transaction, go ahead and exit */
+	if (block_group->cache_generation == trans->transid &&
+	    i_size_read(inode)) {
+		dcs = BTRFS_DC_SETUP;
+		goto out_put;
+	}
+
 	/*
 	 * We want to set the generation to 0, that way if anything goes wrong
 	 * from here on out we know not to trust this cache when we load up next
@@ -2749,12 +2773,15 @@ again:
 	if (!ret)
 		dcs = BTRFS_DC_SETUP;
 	btrfs_free_reserved_data_space(inode, num_pages);
+
 out_put:
 	iput(inode);
 out_free:
 	btrfs_release_path(path);
 out:
 	spin_lock(&block_group->lock);
+	if (!ret)
+		block_group->cache_generation = trans->transid;
 	block_group->disk_cache_state = dcs;
 	spin_unlock(&block_group->lock);
 
@@ -3122,16 +3149,13 @@ commit_trans:
 		return -ENOSPC;
 	}
 	data_sinfo->bytes_may_use += bytes;
-	BTRFS_I(inode)->reserved_bytes += bytes;
 	spin_unlock(&data_sinfo->lock);
 
 	return 0;
 }
 
 /*
- * called when we are clearing an delalloc extent from the
- * inode's io_tree or there was an error for whatever reason
- * after calling btrfs_check_data_free_space
+ * Called if we need to clear a data reservation for this inode.
  */
 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
 {
@@ -3144,7 +3168,6 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
 	data_sinfo = BTRFS_I(inode)->space_info;
 	spin_lock(&data_sinfo->lock);
 	data_sinfo->bytes_may_use -= bytes;
-	BTRFS_I(inode)->reserved_bytes -= bytes;
 	spin_unlock(&data_sinfo->lock);
 }
 
@@ -3165,6 +3188,7 @@ static int should_alloc_chunk(struct btrfs_root *root,
 			      struct btrfs_space_info *sinfo, u64 alloc_bytes,
 			      int force)
 {
+	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
 	u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
 	u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
 	u64 thresh;
@@ -3173,6 +3197,13 @@ static int should_alloc_chunk(struct btrfs_root *root,
 		return 1;
 
 	/*
+	 * We need to take into account the global rsv because for all intents
+	 * and purposes it's used space.  Don't worry about locking the
+	 * global_rsv, it doesn't change except when the transaction commits.
+	 */
+	num_allocated += global_rsv->size;
+
+	/*
 	 * in limited mode, we want to have some free space up to
 	 * about 1% of the FS size.
 	 */
@@ -3303,7 +3334,8 @@ out:
  * shrink metadata reservation for delalloc
  */
 static int shrink_delalloc(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root, u64 to_reclaim, int sync)
+			   struct btrfs_root *root, u64 to_reclaim,
+			   bool wait_ordered)
 {
 	struct btrfs_block_rsv *block_rsv;
 	struct btrfs_space_info *space_info;
@@ -3311,7 +3343,7 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 	u64 max_reclaim;
 	u64 reclaimed = 0;
 	long time_left;
-	int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
+	unsigned long nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
 	int loops = 0;
 	unsigned long progress;
 
@@ -3319,7 +3351,7 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 	space_info = block_rsv->space_info;
 
 	smp_mb();
-	reserved = space_info->bytes_reserved;
+	reserved = space_info->bytes_may_use;
 	progress = space_info->reservation_progress;
 
 	if (reserved == 0)
@@ -3334,7 +3366,8 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 	}
 
 	max_reclaim = min(reserved, to_reclaim);
-
+	nr_pages = max_t(unsigned long, nr_pages,
+			 max_reclaim >> PAGE_CACHE_SHIFT);
 	while (loops < 1024) {
 		/* have the flusher threads jump in and do some IO */
 		smp_mb();
@@ -3343,9 +3376,9 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 		writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
 
 		spin_lock(&space_info->lock);
-		if (reserved > space_info->bytes_reserved)
-			reclaimed += reserved - space_info->bytes_reserved;
-		reserved = space_info->bytes_reserved;
+		if (reserved > space_info->bytes_may_use)
+			reclaimed += reserved - space_info->bytes_may_use;
+		reserved = space_info->bytes_may_use;
 		spin_unlock(&space_info->lock);
 
 		loops++;
@@ -3356,11 +3389,15 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 		if (trans && trans->transaction->blocked)
 			return -EAGAIN;
 
-		time_left = schedule_timeout_interruptible(1);
+		if (wait_ordered && !trans) {
+			btrfs_wait_ordered_extents(root, 0, 0);
+		} else {
+			time_left = schedule_timeout_interruptible(1);
 
-		/* We were interrupted, exit */
-		if (time_left)
-			break;
+			/* We were interrupted, exit */
+			if (time_left)
+				break;
+		}
 
 		/* we've kicked the IO a few times, if anything has been freed,
 		 * exit.  There is no sense in looping here for a long time
@@ -3375,35 +3412,39 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 		}
 
 	}
-	if (reclaimed >= to_reclaim && !trans)
-		btrfs_wait_ordered_extents(root, 0, 0);
+
 	return reclaimed >= to_reclaim;
 }
 
-/*
- * Retries tells us how many times we've called reserve_metadata_bytes.  The
- * idea is if this is the first call (retries == 0) then we will add to our
- * reserved count if we can't make the allocation in order to hold our place
- * while we go and try and free up space.  That way for retries > 1 we don't try
- * and add space, we just check to see if the amount of unused space is >= the
- * total space, meaning that our reservation is valid.
+/**
+ * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
+ * @root - the root we're allocating for
+ * @block_rsv - the block_rsv we're allocating for
+ * @orig_bytes - the number of bytes we want
+ * @flush - wether or not we can flush to make our reservation
  *
- * However if we don't intend to retry this reservation, pass -1 as retries so
- * that it short circuits this logic.
+ * This will reserve orgi_bytes number of bytes from the space info associated
+ * with the block_rsv.  If there is not enough space it will make an attempt to
+ * flush out space to make room.  It will do this by flushing delalloc if
+ * possible or committing the transaction.  If flush is 0 then no attempts to
+ * regain reservations will be made and this will fail if there is not enough
+ * space already.
  */
-static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root,
+static int reserve_metadata_bytes(struct btrfs_root *root,
 				  struct btrfs_block_rsv *block_rsv,
 				  u64 orig_bytes, int flush)
 {
 	struct btrfs_space_info *space_info = block_rsv->space_info;
-	u64 unused;
+	struct btrfs_trans_handle *trans;
+	u64 used;
 	u64 num_bytes = orig_bytes;
 	int retries = 0;
 	int ret = 0;
 	bool committed = false;
 	bool flushing = false;
+	bool wait_ordered = false;
 
+	trans = (struct btrfs_trans_handle *)current->journal_info;
 again:
 	ret = 0;
 	spin_lock(&space_info->lock);
@@ -3431,9 +3472,9 @@ again:
 	}
 
 	ret = -ENOSPC;
-	unused = space_info->bytes_used + space_info->bytes_reserved +
-		 space_info->bytes_pinned + space_info->bytes_readonly +
-		 space_info->bytes_may_use;
+	used = space_info->bytes_used + space_info->bytes_reserved +
+		space_info->bytes_pinned + space_info->bytes_readonly +
+		space_info->bytes_may_use;
 
 	/*
 	 * The idea here is that we've not already over-reserved the block group
@@ -3442,10 +3483,9 @@ again:
 	 * lets start flushing stuff first and then come back and try to make
 	 * our reservation.
 	 */
-	if (unused <= space_info->total_bytes) {
-		unused = space_info->total_bytes - unused;
-		if (unused >= num_bytes) {
-			space_info->bytes_reserved += orig_bytes;
+	if (used <= space_info->total_bytes) {
+		if (used + orig_bytes <= space_info->total_bytes) {
+			space_info->bytes_may_use += orig_bytes;
 			ret = 0;
 		} else {
 			/*
@@ -3461,10 +3501,60 @@ again:
 		 * amount plus the amount of bytes that we need for this
 		 * reservation.
 		 */
-		num_bytes = unused - space_info->total_bytes +
+		wait_ordered = true;
+		num_bytes = used - space_info->total_bytes +
 			(orig_bytes * (retries + 1));
 	}
 
+	if (ret) {
+		u64 profile = btrfs_get_alloc_profile(root, 0);
+		u64 avail;
+
+		/*
+		 * If we have a lot of space that's pinned, don't bother doing
+		 * the overcommit dance yet and just commit the transaction.
+		 */
+		avail = (space_info->total_bytes - space_info->bytes_used) * 8;
+		do_div(avail, 10);
+		if (space_info->bytes_pinned >= avail && flush && !trans &&
+		    !committed) {
+			space_info->flush = 1;
+			flushing = true;
+			spin_unlock(&space_info->lock);
+			goto commit;
+		}
+
+		spin_lock(&root->fs_info->free_chunk_lock);
+		avail = root->fs_info->free_chunk_space;
+
+		/*
+		 * If we have dup, raid1 or raid10 then only half of the free
+		 * space is actually useable.
+		 */
+		if (profile & (BTRFS_BLOCK_GROUP_DUP |
+			       BTRFS_BLOCK_GROUP_RAID1 |
+			       BTRFS_BLOCK_GROUP_RAID10))
+			avail >>= 1;
+
+		/*
+		 * If we aren't flushing don't let us overcommit too much, say
+		 * 1/8th of the space.  If we can flush, let it overcommit up to
+		 * 1/2 of the space.
+		 */
+		if (flush)
+			avail >>= 3;
+		else
+			avail >>= 1;
+		 spin_unlock(&root->fs_info->free_chunk_lock);
+
+		if (used + num_bytes < space_info->total_bytes + avail) {
+			space_info->bytes_may_use += orig_bytes;
+			ret = 0;
+		} else {
+			wait_ordered = true;
+		}
+	}
+
 	/*
 	 * Couldn't make our reservation, save our place so while we're trying
 	 * to reclaim space we can actually use it instead of somebody else
@@ -3484,7 +3574,7 @@ again:
 	 * We do synchronous shrinking since we don't actually unreserve
 	 * metadata until after the IO is completed.
 	 */
-	ret = shrink_delalloc(trans, root, num_bytes, 1);
+	ret = shrink_delalloc(trans, root, num_bytes, wait_ordered);
 	if (ret < 0)
 		goto out;
 
@@ -3496,25 +3586,16 @@ again:
 	 * so go back around and try again.
 	 */
 	if (retries < 2) {
+		wait_ordered = true;
 		retries++;
 		goto again;
 	}
 
-	/*
-	 * Not enough space to be reclaimed, don't bother committing the
-	 * transaction.
-	 */
-	spin_lock(&space_info->lock);
-	if (space_info->bytes_pinned < orig_bytes)
-		ret = -ENOSPC;
-	spin_unlock(&space_info->lock);
-	if (ret)
-		goto out;
-
 	ret = -EAGAIN;
 	if (trans)
 		goto out;
 
+commit:
 	ret = -ENOSPC;
 	if (committed)
 		goto out;
@@ -3542,10 +3623,12 @@ out:
 static struct btrfs_block_rsv *get_block_rsv(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root)
 {
-	struct btrfs_block_rsv *block_rsv;
-	if (root->ref_cows)
+	struct btrfs_block_rsv *block_rsv = NULL;
+
+	if (root->ref_cows || root == root->fs_info->csum_root)
 		block_rsv = trans->block_rsv;
-	else
+
+	if (!block_rsv)
 		block_rsv = root->block_rsv;
 
 	if (!block_rsv)
@@ -3616,7 +3699,7 @@ static void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
 		}
 		if (num_bytes) {
 			spin_lock(&space_info->lock);
-			space_info->bytes_reserved -= num_bytes;
+			space_info->bytes_may_use -= num_bytes;
 			space_info->reservation_progress++;
 			spin_unlock(&space_info->lock);
 		}
@@ -3640,9 +3723,6 @@ void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
 {
 	memset(rsv, 0, sizeof(*rsv));
 	spin_lock_init(&rsv->lock);
-	atomic_set(&rsv->usage, 1);
-	rsv->priority = 6;
-	INIT_LIST_HEAD(&rsv->list);
 }
 
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
@@ -3663,29 +3743,11 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
 void btrfs_free_block_rsv(struct btrfs_root *root,
 			  struct btrfs_block_rsv *rsv)
 {
-	if (rsv && atomic_dec_and_test(&rsv->usage)) {
-		btrfs_block_rsv_release(root, rsv, (u64)-1);
-		if (!rsv->durable)
-			kfree(rsv);
-	}
-}
-
-/*
- * make the block_rsv struct be able to capture freed space.
- * the captured space will re-add to the the block_rsv struct
- * after transaction commit
- */
-void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
-				 struct btrfs_block_rsv *block_rsv)
-{
-	block_rsv->durable = 1;
-	mutex_lock(&fs_info->durable_block_rsv_mutex);
-	list_add_tail(&block_rsv->list, &fs_info->durable_block_rsv_list);
-	mutex_unlock(&fs_info->durable_block_rsv_mutex);
+	btrfs_block_rsv_release(root, rsv, (u64)-1);
+	kfree(rsv);
 }
 
-int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root,
+int btrfs_block_rsv_add(struct btrfs_root *root,
 			struct btrfs_block_rsv *block_rsv,
 			u64 num_bytes)
 {
@@ -3694,7 +3756,7 @@ int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
 	if (num_bytes == 0)
 		return 0;
 
-	ret = reserve_metadata_bytes(trans, root, block_rsv, num_bytes, 1);
+	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, 1);
 	if (!ret) {
 		block_rsv_add_bytes(block_rsv, num_bytes, 1);
 		return 0;
@@ -3703,55 +3765,52 @@ int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  struct btrfs_block_rsv *block_rsv,
-			  u64 min_reserved, int min_factor)
+int btrfs_block_rsv_check(struct btrfs_root *root,
+			  struct btrfs_block_rsv *block_rsv, int min_factor)
 {
 	u64 num_bytes = 0;
-	int commit_trans = 0;
 	int ret = -ENOSPC;
 
 	if (!block_rsv)
 		return 0;
 
 	spin_lock(&block_rsv->lock);
-	if (min_factor > 0)
-		num_bytes = div_factor(block_rsv->size, min_factor);
-	if (min_reserved > num_bytes)
-		num_bytes = min_reserved;
+	num_bytes = div_factor(block_rsv->size, min_factor);
+	if (block_rsv->reserved >= num_bytes)
+		ret = 0;
+	spin_unlock(&block_rsv->lock);
 
-	if (block_rsv->reserved >= num_bytes) {
+	return ret;
+}
+
+int btrfs_block_rsv_refill(struct btrfs_root *root,
+			  struct btrfs_block_rsv *block_rsv,
+			  u64 min_reserved)
+{
+	u64 num_bytes = 0;
+	int ret = -ENOSPC;
+
+	if (!block_rsv)
+		return 0;
+
+	spin_lock(&block_rsv->lock);
+	num_bytes = min_reserved;
+	if (block_rsv->reserved >= num_bytes)
 		ret = 0;
-	} else {
+	else
 		num_bytes -= block_rsv->reserved;
-		if (block_rsv->durable &&
-		    block_rsv->freed[0] + block_rsv->freed[1] >= num_bytes)
-			commit_trans = 1;
-	}
 	spin_unlock(&block_rsv->lock);
+
 	if (!ret)
 		return 0;
 
-	if (block_rsv->refill_used) {
-		ret = reserve_metadata_bytes(trans, root, block_rsv,
-					     num_bytes, 0);
-		if (!ret) {
-			block_rsv_add_bytes(block_rsv, num_bytes, 0);
-			return 0;
-		}
-	}
-
-	if (commit_trans) {
-		if (trans)
-			return -EAGAIN;
-		trans = btrfs_join_transaction(root);
-		BUG_ON(IS_ERR(trans));
-		ret = btrfs_commit_transaction(trans, root);
+	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, 1);
+	if (!ret) {
+		block_rsv_add_bytes(block_rsv, num_bytes, 0);
 		return 0;
 	}
 
-	return -ENOSPC;
+	return ret;
 }
 
 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
@@ -3827,12 +3886,12 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
 	if (sinfo->total_bytes > num_bytes) {
 		num_bytes = sinfo->total_bytes - num_bytes;
 		block_rsv->reserved += num_bytes;
-		sinfo->bytes_reserved += num_bytes;
+		sinfo->bytes_may_use += num_bytes;
 	}
 
 	if (block_rsv->reserved >= block_rsv->size) {
 		num_bytes = block_rsv->reserved - block_rsv->size;
-		sinfo->bytes_reserved -= num_bytes;
+		sinfo->bytes_may_use -= num_bytes;
 		sinfo->reservation_progress++;
 		block_rsv->reserved = block_rsv->size;
 		block_rsv->full = 1;
@@ -3848,16 +3907,12 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
 
 	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 	fs_info->chunk_block_rsv.space_info = space_info;
-	fs_info->chunk_block_rsv.priority = 10;
 
 	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 	fs_info->global_block_rsv.space_info = space_info;
-	fs_info->global_block_rsv.priority = 10;
-	fs_info->global_block_rsv.refill_used = 1;
 	fs_info->delalloc_block_rsv.space_info = space_info;
 	fs_info->trans_block_rsv.space_info = space_info;
 	fs_info->empty_block_rsv.space_info = space_info;
-	fs_info->empty_block_rsv.priority = 10;
 
 	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
 	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
@@ -3865,10 +3920,6 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
 	fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
 	fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
 
-	btrfs_add_durable_block_rsv(fs_info, &fs_info->global_block_rsv);
-
-	btrfs_add_durable_block_rsv(fs_info, &fs_info->delalloc_block_rsv);
-
 	update_global_block_rsv(fs_info);
 }
 
@@ -3883,46 +3934,13 @@ static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
 }
 
-int btrfs_truncate_reserve_metadata(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
-				    struct btrfs_block_rsv *rsv)
-{
-	struct btrfs_block_rsv *trans_rsv = &root->fs_info->trans_block_rsv;
-	u64 num_bytes;
-	int ret;
-
-	/*
-	 * Truncate should be freeing data, but give us 2 items just in case it
-	 * needs to use some space.  We may want to be smarter about this in the
-	 * future.
-	 */
-	num_bytes = btrfs_calc_trans_metadata_size(root, 2);
-
-	/* We already have enough bytes, just return */
-	if (rsv->reserved >= num_bytes)
-		return 0;
-
-	num_bytes -= rsv->reserved;
-
-	/*
-	 * You should have reserved enough space before hand to do this, so this
-	 * should not fail.
-	 */
-	ret = block_rsv_migrate_bytes(trans_rsv, rsv, num_bytes);
-	BUG_ON(ret);
-
-	return 0;
-}
-
 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
 				  struct btrfs_root *root)
 {
 	if (!trans->bytes_reserved)
 		return;
 
-	BUG_ON(trans->block_rsv != &root->fs_info->trans_block_rsv);
-	btrfs_block_rsv_release(root, trans->block_rsv,
-				trans->bytes_reserved);
+	btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
 	trans->bytes_reserved = 0;
 }
 
@@ -3964,11 +3982,19 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
 	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
+/**
+ * drop_outstanding_extent - drop an outstanding extent
+ * @inode: the inode we're dropping the extent for
+ *
+ * This is called when we are freeing up an outstanding extent, either called
+ * after an error or after an extent is written.  This will return the number of
+ * reserved extents that need to be freed.  This must be called with
+ * BTRFS_I(inode)->lock held.
+ */
 static unsigned drop_outstanding_extent(struct inode *inode)
 {
 	unsigned dropped_extents = 0;
 
-	spin_lock(&BTRFS_I(inode)->lock);
 	BUG_ON(!BTRFS_I(inode)->outstanding_extents);
 	BTRFS_I(inode)->outstanding_extents--;
 
@@ -3978,19 +4004,70 @@ static unsigned drop_outstanding_extent(struct inode *inode)
 	 */
 	if (BTRFS_I(inode)->outstanding_extents >=
 	    BTRFS_I(inode)->reserved_extents)
-		goto out;
+		return 0;
 
 	dropped_extents = BTRFS_I(inode)->reserved_extents -
 		BTRFS_I(inode)->outstanding_extents;
 	BTRFS_I(inode)->reserved_extents -= dropped_extents;
-out:
-	spin_unlock(&BTRFS_I(inode)->lock);
 	return dropped_extents;
 }
 
-static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes)
+/**
+ * calc_csum_metadata_size - return the amount of metada space that must be
+ *	reserved/free'd for the given bytes.
+ * @inode: the inode we're manipulating
+ * @num_bytes: the number of bytes in question
+ * @reserve: 1 if we are reserving space, 0 if we are freeing space
+ *
+ * This adjusts the number of csum_bytes in the inode and then returns the
+ * correct amount of metadata that must either be reserved or freed.  We
+ * calculate how many checksums we can fit into one leaf and then divide the
+ * number of bytes that will need to be checksumed by this value to figure out
+ * how many checksums will be required.  If we are adding bytes then the number
+ * may go up and we will return the number of additional bytes that must be
+ * reserved.  If it is going down we will return the number of bytes that must
+ * be freed.
+ *
+ * This must be called with BTRFS_I(inode)->lock held.
+ */
+static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
+				   int reserve)
 {
-	return num_bytes >>= 3;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	u64 csum_size;
+	int num_csums_per_leaf;
+	int num_csums;
+	int old_csums;
+
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
+	    BTRFS_I(inode)->csum_bytes == 0)
+		return 0;
+
+	old_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
+	if (reserve)
+		BTRFS_I(inode)->csum_bytes += num_bytes;
+	else
+		BTRFS_I(inode)->csum_bytes -= num_bytes;
+	csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
+	num_csums_per_leaf = (int)div64_u64(csum_size,
+					    sizeof(struct btrfs_csum_item) +
+					    sizeof(struct btrfs_disk_key));
+	num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
+	num_csums = num_csums + num_csums_per_leaf - 1;
+	num_csums = num_csums / num_csums_per_leaf;
+
+	old_csums = old_csums + num_csums_per_leaf - 1;
+	old_csums = old_csums / num_csums_per_leaf;
+
+	/* No change, no need to reserve more */
+	if (old_csums == num_csums)
+		return 0;
+
+	if (reserve)
+		return btrfs_calc_trans_metadata_size(root,
+						      num_csums - old_csums);
+
+	return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
 }
 
 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
@@ -3999,9 +4076,13 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
 	u64 to_reserve = 0;
 	unsigned nr_extents = 0;
+	int flush = 1;
 	int ret;
 
-	if (btrfs_transaction_in_commit(root->fs_info))
+	if (btrfs_is_free_space_inode(root, inode))
+		flush = 0;
+
+	if (flush && btrfs_transaction_in_commit(root->fs_info))
 		schedule_timeout(1);
 
 	num_bytes = ALIGN(num_bytes, root->sectorsize);
@@ -4017,18 +4098,29 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 
 		to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
 	}
+	to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
 	spin_unlock(&BTRFS_I(inode)->lock);
 
-	to_reserve += calc_csum_metadata_size(inode, num_bytes);
-	ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
+	ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
 	if (ret) {
+		u64 to_free = 0;
 		unsigned dropped;
+
+		spin_lock(&BTRFS_I(inode)->lock);
+		dropped = drop_outstanding_extent(inode);
+		to_free = calc_csum_metadata_size(inode, num_bytes, 0);
+		spin_unlock(&BTRFS_I(inode)->lock);
+		to_free += btrfs_calc_trans_metadata_size(root, dropped);
+
 		/*
-		 * We don't need the return value since our reservation failed,
-		 * we just need to clean up our counter.
+		 * Somebody could have come in and twiddled with the
+		 * reservation, so if we have to free more than we would have
+		 * reserved from this reservation go ahead and release those
+		 * bytes.
 		 */
-		dropped = drop_outstanding_extent(inode);
-		WARN_ON(dropped > 1);
+		to_free -= to_reserve;
+		if (to_free)
+			btrfs_block_rsv_release(root, block_rsv, to_free);
 		return ret;
 	}
 
@@ -4037,6 +4129,15 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	return 0;
 }
 
+/**
+ * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
+ * @inode: the inode to release the reservation for
+ * @num_bytes: the number of bytes we're releasing
+ *
+ * This will release the metadata reservation for an inode.  This can be called
+ * once we complete IO for a given set of bytes to release their metadata
+ * reservations.
+ */
 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -4044,9 +4145,11 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 	unsigned dropped;
 
 	num_bytes = ALIGN(num_bytes, root->sectorsize);
+	spin_lock(&BTRFS_I(inode)->lock);
 	dropped = drop_outstanding_extent(inode);
 
-	to_free = calc_csum_metadata_size(inode, num_bytes);
+	to_free = calc_csum_metadata_size(inode, num_bytes, 0);
+	spin_unlock(&BTRFS_I(inode)->lock);
 	if (dropped > 0)
 		to_free += btrfs_calc_trans_metadata_size(root, dropped);
 
@@ -4054,6 +4157,21 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 				to_free);
 }
 
+/**
+ * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
+ * @inode: inode we're writing to
+ * @num_bytes: the number of bytes we want to allocate
+ *
+ * This will do the following things
+ *
+ * o reserve space in the data space info for num_bytes
+ * o reserve space in the metadata space info based on number of outstanding
+ *   extents and how much csums will be needed
+ * o add to the inodes ->delalloc_bytes
+ * o add it to the fs_info's delalloc inodes list.
+ *
+ * This will return 0 for success and -ENOSPC if there is no space left.
+ */
 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
 {
 	int ret;
@@ -4071,6 +4189,19 @@ int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
 	return 0;
 }
 
+/**
+ * btrfs_delalloc_release_space - release data and metadata space for delalloc
+ * @inode: inode we're releasing space for
+ * @num_bytes: the number of bytes we want to free up
+ *
+ * This must be matched with a call to btrfs_delalloc_reserve_space.  This is
+ * called in the case that we don't need the metadata AND data reservations
+ * anymore.  So if there is an error or we insert an inline extent.
+ *
+ * This function will release the metadata space that was not used and will
+ * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
+ * list if there are no delalloc bytes left.
+ */
 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
 {
 	btrfs_delalloc_release_metadata(inode, num_bytes);
@@ -4123,7 +4254,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
 		spin_lock(&cache->space_info->lock);
 		spin_lock(&cache->lock);
 
-		if (btrfs_super_cache_generation(&info->super_copy) != 0 &&
+		if (btrfs_test_opt(root, SPACE_CACHE) &&
 		    cache->disk_cache_state < BTRFS_DC_CLEAR)
 			cache->disk_cache_state = BTRFS_DC_CLEAR;
 
@@ -4135,7 +4266,6 @@ static int update_block_group(struct btrfs_trans_handle *trans,
 			btrfs_set_block_group_used(&cache->item, old_val);
 			cache->reserved -= num_bytes;
 			cache->space_info->bytes_reserved -= num_bytes;
-			cache->space_info->reservation_progress++;
 			cache->space_info->bytes_used += num_bytes;
 			cache->space_info->disk_used += num_bytes * factor;
 			spin_unlock(&cache->lock);
@@ -4187,7 +4317,6 @@ static int pin_down_extent(struct btrfs_root *root,
 	if (reserved) {
 		cache->reserved -= num_bytes;
 		cache->space_info->bytes_reserved -= num_bytes;
-		cache->space_info->reservation_progress++;
 	}
 	spin_unlock(&cache->lock);
 	spin_unlock(&cache->space_info->lock);
@@ -4214,46 +4343,55 @@ int btrfs_pin_extent(struct btrfs_root *root,
 	return 0;
 }
 
-/*
- * update size of reserved extents. this function may return -EAGAIN
- * if 'reserve' is true or 'sinfo' is false.
+/**
+ * btrfs_update_reserved_bytes - update the block_group and space info counters
+ * @cache:	The cache we are manipulating
+ * @num_bytes:	The number of bytes in question
+ * @reserve:	One of the reservation enums
+ *
+ * This is called by the allocator when it reserves space, or by somebody who is
+ * freeing space that was never actually used on disk.  For example if you
+ * reserve some space for a new leaf in transaction A and before transaction A
+ * commits you free that leaf, you call this with reserve set to 0 in order to
+ * clear the reservation.
+ *
+ * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
+ * ENOSPC accounting.  For data we handle the reservation through clearing the
+ * delalloc bits in the io_tree.  We have to do this since we could end up
+ * allocating less disk space for the amount of data we have reserved in the
+ * case of compression.
+ *
+ * If this is a reservation and the block group has become read only we cannot
+ * make the reservation and return -EAGAIN, otherwise this function always
+ * succeeds.
  */
-int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-				u64 num_bytes, int reserve, int sinfo)
+static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
+				       u64 num_bytes, int reserve)
 {
+	struct btrfs_space_info *space_info = cache->space_info;
 	int ret = 0;
-	if (sinfo) {
-		struct btrfs_space_info *space_info = cache->space_info;
-		spin_lock(&space_info->lock);
-		spin_lock(&cache->lock);
-		if (reserve) {
-			if (cache->ro) {
-				ret = -EAGAIN;
-			} else {
-				cache->reserved += num_bytes;
-				space_info->bytes_reserved += num_bytes;
-			}
-		} else {
-			if (cache->ro)
-				space_info->bytes_readonly += num_bytes;
-			cache->reserved -= num_bytes;
-			space_info->bytes_reserved -= num_bytes;
-			space_info->reservation_progress++;
-		}
-		spin_unlock(&cache->lock);
-		spin_unlock(&space_info->lock);
-	} else {
-		spin_lock(&cache->lock);
+	spin_lock(&space_info->lock);
+	spin_lock(&cache->lock);
+	if (reserve != RESERVE_FREE) {
 		if (cache->ro) {
 			ret = -EAGAIN;
 		} else {
-			if (reserve)
-				cache->reserved += num_bytes;
-			else
-				cache->reserved -= num_bytes;
+			cache->reserved += num_bytes;
+			space_info->bytes_reserved += num_bytes;
+			if (reserve == RESERVE_ALLOC) {
+				BUG_ON(space_info->bytes_may_use < num_bytes);
+				space_info->bytes_may_use -= num_bytes;
+			}
 		}
-		spin_unlock(&cache->lock);
+	} else {
+		if (cache->ro)
+			space_info->bytes_readonly += num_bytes;
+		cache->reserved -= num_bytes;
+		space_info->bytes_reserved -= num_bytes;
+		space_info->reservation_progress++;
 	}
+	spin_unlock(&cache->lock);
+	spin_unlock(&space_info->lock);
 	return ret;
 }
 
@@ -4319,13 +4457,8 @@ static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 		spin_lock(&cache->lock);
 		cache->pinned -= len;
 		cache->space_info->bytes_pinned -= len;
-		if (cache->ro) {
+		if (cache->ro)
 			cache->space_info->bytes_readonly += len;
-		} else if (cache->reserved_pinned > 0) {
-			len = min(len, cache->reserved_pinned);
-			cache->reserved_pinned -= len;
-			cache->space_info->bytes_reserved += len;
-		}
 		spin_unlock(&cache->lock);
 		spin_unlock(&cache->space_info->lock);
 	}
@@ -4340,11 +4473,8 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_io_tree *unpin;
-	struct btrfs_block_rsv *block_rsv;
-	struct btrfs_block_rsv *next_rsv;
 	u64 start;
 	u64 end;
-	int idx;
 	int ret;
 
 	if (fs_info->pinned_extents == &fs_info->freed_extents[0])
@@ -4367,30 +4497,6 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
 		cond_resched();
 	}
 
-	mutex_lock(&fs_info->durable_block_rsv_mutex);
-	list_for_each_entry_safe(block_rsv, next_rsv,
-				 &fs_info->durable_block_rsv_list, list) {
-
-		idx = trans->transid & 0x1;
-		if (block_rsv->freed[idx] > 0) {
-			block_rsv_add_bytes(block_rsv,
-					    block_rsv->freed[idx], 0);
-			block_rsv->freed[idx] = 0;
-		}
-		if (atomic_read(&block_rsv->usage) == 0) {
-			btrfs_block_rsv_release(root, block_rsv, (u64)-1);
-
-			if (block_rsv->freed[0] == 0 &&
-			    block_rsv->freed[1] == 0) {
-				list_del_init(&block_rsv->list);
-				kfree(block_rsv);
-			}
-		} else {
-			btrfs_block_rsv_release(root, block_rsv, 0);
-		}
-	}
-	mutex_unlock(&fs_info->durable_block_rsv_mutex);
-
 	return 0;
 }
 
@@ -4668,7 +4774,6 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 			   struct extent_buffer *buf,
 			   u64 parent, int last_ref)
 {
-	struct btrfs_block_rsv *block_rsv;
 	struct btrfs_block_group_cache *cache = NULL;
 	int ret;
 
@@ -4683,64 +4788,24 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 	if (!last_ref)
 		return;
 
-	block_rsv = get_block_rsv(trans, root);
 	cache = btrfs_lookup_block_group(root->fs_info, buf->start);
-	if (block_rsv->space_info != cache->space_info)
-		goto out;
 
 	if (btrfs_header_generation(buf) == trans->transid) {
 		if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
 			ret = check_ref_cleanup(trans, root, buf->start);
 			if (!ret)
-				goto pin;
+				goto out;
 		}
 
 		if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
 			pin_down_extent(root, cache, buf->start, buf->len, 1);
-			goto pin;
+			goto out;
 		}
 
 		WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
 
 		btrfs_add_free_space(cache, buf->start, buf->len);
-		ret = btrfs_update_reserved_bytes(cache, buf->len, 0, 0);
-		if (ret == -EAGAIN) {
-			/* block group became read-only */
-			btrfs_update_reserved_bytes(cache, buf->len, 0, 1);
-			goto out;
-		}
-
-		ret = 1;
-		spin_lock(&block_rsv->lock);
-		if (block_rsv->reserved < block_rsv->size) {
-			block_rsv->reserved += buf->len;
-			ret = 0;
-		}
-		spin_unlock(&block_rsv->lock);
-
-		if (ret) {
-			spin_lock(&cache->space_info->lock);
-			cache->space_info->bytes_reserved -= buf->len;
-			cache->space_info->reservation_progress++;
-			spin_unlock(&cache->space_info->lock);
-		}
-		goto out;
-	}
-pin:
-	if (block_rsv->durable && !cache->ro) {
-		ret = 0;
-		spin_lock(&cache->lock);
-		if (!cache->ro) {
-			cache->reserved_pinned += buf->len;
-			ret = 1;
-		}
-		spin_unlock(&cache->lock);
-
-		if (ret) {
-			spin_lock(&block_rsv->lock);
-			block_rsv->freed[trans->transid & 0x1] += buf->len;
-			spin_unlock(&block_rsv->lock);
-		}
+		btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
 	}
 out:
 	/*
@@ -4883,6 +4948,8 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
 	int last_ptr_loop = 0;
 	int loop = 0;
 	int index = 0;
+	int alloc_type = (data & BTRFS_BLOCK_GROUP_DATA) ?
+		RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
 	bool found_uncached_bg = false;
 	bool failed_cluster_refill = false;
 	bool failed_alloc = false;
@@ -5202,8 +5269,8 @@ checks:
 					     search_start - offset);
 		BUG_ON(offset > search_start);
 
-		ret = btrfs_update_reserved_bytes(block_group, num_bytes, 1,
-					    (data & BTRFS_BLOCK_GROUP_DATA));
+		ret = btrfs_update_reserved_bytes(block_group, num_bytes,
+						  alloc_type);
 		if (ret == -EAGAIN) {
 			btrfs_add_free_space(block_group, offset, num_bytes);
 			goto loop;
@@ -5325,7 +5392,8 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
 	int index = 0;
 
 	spin_lock(&info->lock);
-	printk(KERN_INFO "space_info has %llu free, is %sfull\n",
+	printk(KERN_INFO "space_info %llu has %llu free, is %sfull\n",
+	       (unsigned long long)info->flags,
 	       (unsigned long long)(info->total_bytes - info->bytes_used -
 				    info->bytes_pinned - info->bytes_reserved -
 				    info->bytes_readonly),
@@ -5427,7 +5495,7 @@ int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
 		ret = btrfs_discard_extent(root, start, len, NULL);
 
 	btrfs_add_free_space(cache, start, len);
-	btrfs_update_reserved_bytes(cache, len, 0, 1);
+	btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
 	btrfs_put_block_group(cache);
 
 	trace_btrfs_reserved_extent_free(root, start, len);
@@ -5630,7 +5698,8 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
 		put_caching_control(caching_ctl);
 	}
 
-	ret = btrfs_update_reserved_bytes(block_group, ins->offset, 1, 1);
+	ret = btrfs_update_reserved_bytes(block_group, ins->offset,
+					  RESERVE_ALLOC_NO_ACCOUNT);
 	BUG_ON(ret);
 	btrfs_put_block_group(block_group);
 	ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
@@ -5687,8 +5756,7 @@ use_block_rsv(struct btrfs_trans_handle *trans,
 	block_rsv = get_block_rsv(trans, root);
 
 	if (block_rsv->size == 0) {
-		ret = reserve_metadata_bytes(trans, root, block_rsv,
-					     blocksize, 0);
+		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0);
 		/*
 		 * If we couldn't reserve metadata bytes try and use some from
 		 * the global reserve.
@@ -5709,12 +5777,8 @@ use_block_rsv(struct btrfs_trans_handle *trans,
 		return block_rsv;
 	if (ret) {
 		WARN_ON(1);
-		ret = reserve_metadata_bytes(trans, root, block_rsv, blocksize,
-					     0);
+		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0);
 		if (!ret) {
-			spin_lock(&block_rsv->lock);
-			block_rsv->size += blocksize;
-			spin_unlock(&block_rsv->lock);
 			return block_rsv;
 		} else if (ret && block_rsv != global_rsv) {
 			ret = block_rsv_use_bytes(global_rsv, blocksize);
@@ -6592,12 +6656,9 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 		    cache->bytes_super - btrfs_block_group_used(&cache->item);
 
 	if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
-	    sinfo->bytes_may_use + sinfo->bytes_readonly +
-	    cache->reserved_pinned + num_bytes + min_allocable_bytes <=
-	    sinfo->total_bytes) {
+	    sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
+	    min_allocable_bytes <= sinfo->total_bytes) {
 		sinfo->bytes_readonly += num_bytes;
-		sinfo->bytes_reserved += cache->reserved_pinned;
-		cache->reserved_pinned = 0;
 		cache->ro = 1;
 		ret = 0;
 	}
@@ -6964,7 +7025,8 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 					struct btrfs_space_info,
 					list);
 		if (space_info->bytes_pinned > 0 ||
-		    space_info->bytes_reserved > 0) {
+		    space_info->bytes_reserved > 0 ||
+		    space_info->bytes_may_use > 0) {
 			WARN_ON(1);
 			dump_space_info(space_info, 0, 0);
 		}
@@ -7007,13 +7069,11 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 	path->reada = 1;
 
 	cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
-	if (cache_gen != 0 &&
+	if (btrfs_test_opt(root, SPACE_CACHE) &&
 	    btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
 		need_clear = 1;
 	if (btrfs_test_opt(root, CLEAR_CACHE))
 		need_clear = 1;
-	if (!btrfs_test_opt(root, SPACE_CACHE) && cache_gen)
-		printk(KERN_INFO "btrfs: disk space caching is enabled\n");
 
 	while (1) {
 		ret = find_first_block_group(root, path, &key);
@@ -7268,7 +7328,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 			spin_unlock(&block_group->lock);
 		}
 		/* One for our lookup ref */
-		iput(inode);
+		btrfs_add_delayed_iput(inode);
 	}
 
 	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d418164a35f..0ada0b700b4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -894,6 +894,194 @@ search_again:
 	goto again;
 }
 
+/**
+ * convert_extent - convert all bits in a given range from one bit to another
+ * @tree:	the io tree to search
+ * @start:	the start offset in bytes
+ * @end:	the end offset in bytes (inclusive)
+ * @bits:	the bits to set in this range
+ * @clear_bits:	the bits to clear in this range
+ * @mask:	the allocation mask
+ *
+ * This will go through and set bits for the given range.  If any states exist
+ * already in this range they are set with the given bit and cleared of the
+ * clear_bits.  This is only meant to be used by things that are mergeable, ie
+ * converting from say DELALLOC to DIRTY.  This is not meant to be used with
+ * boundary bits like LOCK.
+ */
+int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
+		       int bits, int clear_bits, gfp_t mask)
+{
+	struct extent_state *state;
+	struct extent_state *prealloc = NULL;
+	struct rb_node *node;
+	int err = 0;
+	u64 last_start;
+	u64 last_end;
+
+again:
+	if (!prealloc && (mask & __GFP_WAIT)) {
+		prealloc = alloc_extent_state(mask);
+		if (!prealloc)
+			return -ENOMEM;
+	}
+
+	spin_lock(&tree->lock);
+	/*
+	 * this search will find all the extents that end after
+	 * our range starts.
+	 */
+	node = tree_search(tree, start);
+	if (!node) {
+		prealloc = alloc_extent_state_atomic(prealloc);
+		if (!prealloc)
+			return -ENOMEM;
+		err = insert_state(tree, prealloc, start, end, &bits);
+		prealloc = NULL;
+		BUG_ON(err == -EEXIST);
+		goto out;
+	}
+	state = rb_entry(node, struct extent_state, rb_node);
+hit_next:
+	last_start = state->start;
+	last_end = state->end;
+
+	/*
+	 * | ---- desired range ---- |
+	 * | state |
+	 *
+	 * Just lock what we found and keep going
+	 */
+	if (state->start == start && state->end <= end) {
+		struct rb_node *next_node;
+
+		set_state_bits(tree, state, &bits);
+		clear_state_bit(tree, state, &clear_bits, 0);
+
+		merge_state(tree, state);
+		if (last_end == (u64)-1)
+			goto out;
+
+		start = last_end + 1;
+		next_node = rb_next(&state->rb_node);
+		if (next_node && start < end && prealloc && !need_resched()) {
+			state = rb_entry(next_node, struct extent_state,
+					 rb_node);
+			if (state->start == start)
+				goto hit_next;
+		}
+		goto search_again;
+	}
+
+	/*
+	 *     | ---- desired range ---- |
+	 * | state |
+	 *   or
+	 * | ------------- state -------------- |
+	 *
+	 * We need to split the extent we found, and may flip bits on
+	 * second half.
+	 *
+	 * If the extent we found extends past our
+	 * range, we just split and search again.  It'll get split
+	 * again the next time though.
+	 *
+	 * If the extent we found is inside our range, we set the
+	 * desired bit on it.
+	 */
+	if (state->start < start) {
+		prealloc = alloc_extent_state_atomic(prealloc);
+		if (!prealloc)
+			return -ENOMEM;
+		err = split_state(tree, state, prealloc, start);
+		BUG_ON(err == -EEXIST);
+		prealloc = NULL;
+		if (err)
+			goto out;
+		if (state->end <= end) {
+			set_state_bits(tree, state, &bits);
+			clear_state_bit(tree, state, &clear_bits, 0);
+			merge_state(tree, state);
+			if (last_end == (u64)-1)
+				goto out;
+			start = last_end + 1;
+		}
+		goto search_again;
+	}
+	/*
+	 * | ---- desired range ---- |
+	 *     | state | or               | state |
+	 *
+	 * There's a hole, we need to insert something in it and
+	 * ignore the extent we found.
+	 */
+	if (state->start > start) {
+		u64 this_end;
+		if (end < last_start)
+			this_end = end;
+		else
+			this_end = last_start - 1;
+
+		prealloc = alloc_extent_state_atomic(prealloc);
+		if (!prealloc)
+			return -ENOMEM;
+
+		/*
+		 * Avoid to free 'prealloc' if it can be merged with
+		 * the later extent.
+		 */
+		err = insert_state(tree, prealloc, start, this_end,
+				   &bits);
+		BUG_ON(err == -EEXIST);
+		if (err) {
+			free_extent_state(prealloc);
+			prealloc = NULL;
+			goto out;
+		}
+		prealloc = NULL;
+		start = this_end + 1;
+		goto search_again;
+	}
+	/*
+	 * | ---- desired range ---- |
+	 *                        | state |
+	 * We need to split the extent, and set the bit
+	 * on the first half
+	 */
+	if (state->start <= end && state->end > end) {
+		prealloc = alloc_extent_state_atomic(prealloc);
+		if (!prealloc)
+			return -ENOMEM;
+
+		err = split_state(tree, state, prealloc, end + 1);
+		BUG_ON(err == -EEXIST);
+
+		set_state_bits(tree, prealloc, &bits);
+		clear_state_bit(tree, prealloc, &clear_bits, 0);
+
+		merge_state(tree, prealloc);
+		prealloc = NULL;
+		goto out;
+	}
+
+	goto search_again;
+
+out:
+	spin_unlock(&tree->lock);
+	if (prealloc)
+		free_extent_state(prealloc);
+
+	return err;
+
+search_again:
+	if (start > end)
+		goto out;
+	spin_unlock(&tree->lock);
+	if (mask & __GFP_WAIT)
+		cond_resched();
+	goto again;
+}
+
 /* wrappers around set/clear extent bit */
 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 		     gfp_t mask)
@@ -2136,6 +2324,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 	int compressed;
 	int write_flags;
 	unsigned long nr_written = 0;
+	bool fill_delalloc = true;
 
 	if (wbc->sync_mode == WB_SYNC_ALL)
 		write_flags = WRITE_SYNC;
@@ -2166,10 +2355,13 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 
 	set_page_extent_mapped(page);
 
+	if (!tree->ops || !tree->ops->fill_delalloc)
+		fill_delalloc = false;
+
 	delalloc_start = start;
 	delalloc_end = 0;
 	page_started = 0;
-	if (!epd->extent_locked) {
+	if (!epd->extent_locked && fill_delalloc) {
 		u64 delalloc_to_write = 0;
 		/*
 		 * make sure the wbc mapping index is at least updated
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 7b2f0c3e792..325a346369d 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -17,6 +17,7 @@
 #define EXTENT_NODATASUM (1 << 10)
 #define EXTENT_DO_ACCOUNTING (1 << 11)
 #define EXTENT_FIRST_DELALLOC (1 << 12)
+#define EXTENT_NEED_WAIT (1 << 13)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
 #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
 
@@ -214,6 +215,8 @@ int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 		     gfp_t mask);
 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 		       gfp_t mask);
+int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
+		       int bits, int clear_bits, gfp_t mask);
 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
 			struct extent_state **cached_state, gfp_t mask);
 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index e4e57d59edb..f2e92828960 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1069,6 +1069,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
 	int i;
 	unsigned long index = pos >> PAGE_CACHE_SHIFT;
 	struct inode *inode = fdentry(file)->d_inode;
+	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 	int err = 0;
 	int faili = 0;
 	u64 start_pos;
@@ -1080,7 +1081,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
 again:
 	for (i = 0; i < num_pages; i++) {
 		pages[i] = find_or_create_page(inode->i_mapping, index + i,
-					       GFP_NOFS);
+					       mask);
 		if (!pages[i]) {
 			faili = i - 1;
 			err = -ENOMEM;
@@ -1615,10 +1616,6 @@ static long btrfs_fallocate(struct file *file, int mode,
 			goto out;
 	}
 
-	ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
-	if (ret)
-		goto out;
-
 	locked_end = alloc_end - 1;
 	while (1) {
 		struct btrfs_ordered_extent *ordered;
@@ -1664,11 +1661,27 @@ static long btrfs_fallocate(struct file *file, int mode,
 		if (em->block_start == EXTENT_MAP_HOLE ||
 		    (cur_offset >= inode->i_size &&
 		     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+
+			/*
+			 * Make sure we have enough space before we do the
+			 * allocation.
+			 */
+			ret = btrfs_check_data_free_space(inode, last_byte -
+							  cur_offset);
+			if (ret) {
+				free_extent_map(em);
+				break;
+			}
+
 			ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
 							last_byte - cur_offset,
 							1 << inode->i_blkbits,
 							offset + len,
 							&alloc_hint);
+
+			/* Let go of our reservation. */
+			btrfs_free_reserved_data_space(inode, last_byte -
+						       cur_offset);
 			if (ret < 0) {
 				free_extent_map(em);
 				break;
@@ -1694,8 +1707,6 @@ static long btrfs_fallocate(struct file *file, int mode,
 	}
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
 			     &cached_state, GFP_NOFS);
-
-	btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
 out:
 	mutex_unlock(&inode->i_mutex);
 	return ret;
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 41ac927401d..de205d59b74 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/math64.h>
+#include <linux/ratelimit.h>
 #include "ctree.h"
 #include "free-space-cache.h"
 #include "transaction.h"
@@ -84,6 +85,7 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
 				      *block_group, struct btrfs_path *path)
 {
 	struct inode *inode = NULL;
+	u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
 
 	spin_lock(&block_group->lock);
 	if (block_group->inode)
@@ -98,13 +100,14 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root,
 		return inode;
 
 	spin_lock(&block_group->lock);
-	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) {
+	if (!((BTRFS_I(inode)->flags & flags) == flags)) {
 		printk(KERN_INFO "Old style space inode found, converting.\n");
-		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NODATASUM;
+		BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
+			BTRFS_INODE_NODATACOW;
 		block_group->disk_cache_state = BTRFS_DC_CLEAR;
 	}
 
-	if (!btrfs_fs_closing(root->fs_info)) {
+	if (!block_group->iref) {
 		block_group->inode = igrab(inode);
 		block_group->iref = 1;
 	}
@@ -122,12 +125,17 @@ int __create_free_space_inode(struct btrfs_root *root,
 	struct btrfs_free_space_header *header;
 	struct btrfs_inode_item *inode_item;
 	struct extent_buffer *leaf;
+	u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
 	int ret;
 
 	ret = btrfs_insert_empty_inode(trans, root, path, ino);
 	if (ret)
 		return ret;
 
+	/* We inline crc's for the free disk space cache */
+	if (ino != BTRFS_FREE_INO_OBJECTID)
+		flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
+
 	leaf = path->nodes[0];
 	inode_item = btrfs_item_ptr(leaf, path->slots[0],
 				    struct btrfs_inode_item);
@@ -140,8 +148,7 @@ int __create_free_space_inode(struct btrfs_root *root,
 	btrfs_set_inode_uid(leaf, inode_item, 0);
 	btrfs_set_inode_gid(leaf, inode_item, 0);
 	btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
-	btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS |
-			      BTRFS_INODE_PREALLOC);
+	btrfs_set_inode_flags(leaf, inode_item, flags);
 	btrfs_set_inode_nlink(leaf, inode_item, 1);
 	btrfs_set_inode_transid(leaf, inode_item, trans->transid);
 	btrfs_set_inode_block_group(leaf, inode_item, offset);
@@ -196,9 +203,7 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root,
 
 	rsv = trans->block_rsv;
 	trans->block_rsv = root->orphan_block_rsv;
-	ret = btrfs_block_rsv_check(trans, root,
-				    root->orphan_block_rsv,
-				    0, 5);
+	ret = btrfs_block_rsv_check(root, root->orphan_block_rsv, 5);
 	if (ret)
 		return ret;
 
@@ -242,26 +247,342 @@ static int readahead_cache(struct inode *inode)
 	return 0;
 }
 
+struct io_ctl {
+	void *cur, *orig;
+	struct page *page;
+	struct page **pages;
+	struct btrfs_root *root;
+	unsigned long size;
+	int index;
+	int num_pages;
+	unsigned check_crcs:1;
+};
+
+static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
+		       struct btrfs_root *root)
+{
+	memset(io_ctl, 0, sizeof(struct io_ctl));
+	io_ctl->num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+		PAGE_CACHE_SHIFT;
+	io_ctl->pages = kzalloc(sizeof(struct page *) * io_ctl->num_pages,
+				GFP_NOFS);
+	if (!io_ctl->pages)
+		return -ENOMEM;
+	io_ctl->root = root;
+	if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
+		io_ctl->check_crcs = 1;
+	return 0;
+}
+
+static void io_ctl_free(struct io_ctl *io_ctl)
+{
+	kfree(io_ctl->pages);
+}
+
+static void io_ctl_unmap_page(struct io_ctl *io_ctl)
+{
+	if (io_ctl->cur) {
+		kunmap(io_ctl->page);
+		io_ctl->cur = NULL;
+		io_ctl->orig = NULL;
+	}
+}
+
+static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
+{
+	WARN_ON(io_ctl->cur);
+	BUG_ON(io_ctl->index >= io_ctl->num_pages);
+	io_ctl->page = io_ctl->pages[io_ctl->index++];
+	io_ctl->cur = kmap(io_ctl->page);
+	io_ctl->orig = io_ctl->cur;
+	io_ctl->size = PAGE_CACHE_SIZE;
+	if (clear)
+		memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
+}
+
+static void io_ctl_drop_pages(struct io_ctl *io_ctl)
+{
+	int i;
+
+	io_ctl_unmap_page(io_ctl);
+
+	for (i = 0; i < io_ctl->num_pages; i++) {
+		ClearPageChecked(io_ctl->pages[i]);
+		unlock_page(io_ctl->pages[i]);
+		page_cache_release(io_ctl->pages[i]);
+	}
+}
+
+static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
+				int uptodate)
+{
+	struct page *page;
+	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
+	int i;
+
+	for (i = 0; i < io_ctl->num_pages; i++) {
+		page = find_or_create_page(inode->i_mapping, i, mask);
+		if (!page) {
+			io_ctl_drop_pages(io_ctl);
+			return -ENOMEM;
+		}
+		io_ctl->pages[i] = page;
+		if (uptodate && !PageUptodate(page)) {
+			btrfs_readpage(NULL, page);
+			lock_page(page);
+			if (!PageUptodate(page)) {
+				printk(KERN_ERR "btrfs: error reading free "
+				       "space cache\n");
+				io_ctl_drop_pages(io_ctl);
+				return -EIO;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
+{
+	u64 *val;
+
+	io_ctl_map_page(io_ctl, 1);
+
+	/*
+	 * Skip the csum areas.  If we don't check crcs then we just have a
+	 * 64bit chunk at the front of the first page.
+	 */
+	if (io_ctl->check_crcs) {
+		io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
+		io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
+	} else {
+		io_ctl->cur += sizeof(u64);
+		io_ctl->size -= sizeof(u64) * 2;
+	}
+
+	val = io_ctl->cur;
+	*val = cpu_to_le64(generation);
+	io_ctl->cur += sizeof(u64);
+}
+
+static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
+{
+	u64 *gen;
+
+	/*
+	 * Skip the crc area.  If we don't check crcs then we just have a 64bit
+	 * chunk at the front of the first page.
+	 */
+	if (io_ctl->check_crcs) {
+		io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
+		io_ctl->size -= sizeof(u64) +
+			(sizeof(u32) * io_ctl->num_pages);
+	} else {
+		io_ctl->cur += sizeof(u64);
+		io_ctl->size -= sizeof(u64) * 2;
+	}
+
+	gen = io_ctl->cur;
+	if (le64_to_cpu(*gen) != generation) {
+		printk_ratelimited(KERN_ERR "btrfs: space cache generation "
+				   "(%Lu) does not match inode (%Lu)\n", *gen,
+				   generation);
+		io_ctl_unmap_page(io_ctl);
+		return -EIO;
+	}
+	io_ctl->cur += sizeof(u64);
+	return 0;
+}
+
+static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
+{
+	u32 *tmp;
+	u32 crc = ~(u32)0;
+	unsigned offset = 0;
+
+	if (!io_ctl->check_crcs) {
+		io_ctl_unmap_page(io_ctl);
+		return;
+	}
+
+	if (index == 0)
+		offset = sizeof(u32) * io_ctl->num_pages;;
+
+	crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
+			      PAGE_CACHE_SIZE - offset);
+	btrfs_csum_final(crc, (char *)&crc);
+	io_ctl_unmap_page(io_ctl);
+	tmp = kmap(io_ctl->pages[0]);
+	tmp += index;
+	*tmp = crc;
+	kunmap(io_ctl->pages[0]);
+}
+
+static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
+{
+	u32 *tmp, val;
+	u32 crc = ~(u32)0;
+	unsigned offset = 0;
+
+	if (!io_ctl->check_crcs) {
+		io_ctl_map_page(io_ctl, 0);
+		return 0;
+	}
+
+	if (index == 0)
+		offset = sizeof(u32) * io_ctl->num_pages;
+
+	tmp = kmap(io_ctl->pages[0]);
+	tmp += index;
+	val = *tmp;
+	kunmap(io_ctl->pages[0]);
+
+	io_ctl_map_page(io_ctl, 0);
+	crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
+			      PAGE_CACHE_SIZE - offset);
+	btrfs_csum_final(crc, (char *)&crc);
+	if (val != crc) {
+		printk_ratelimited(KERN_ERR "btrfs: csum mismatch on free "
+				   "space cache\n");
+		io_ctl_unmap_page(io_ctl);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
+			    void *bitmap)
+{
+	struct btrfs_free_space_entry *entry;
+
+	if (!io_ctl->cur)
+		return -ENOSPC;
+
+	entry = io_ctl->cur;
+	entry->offset = cpu_to_le64(offset);
+	entry->bytes = cpu_to_le64(bytes);
+	entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
+		BTRFS_FREE_SPACE_EXTENT;
+	io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+	io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+	if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+		return 0;
+
+	io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+
+	/* No more pages to map */
+	if (io_ctl->index >= io_ctl->num_pages)
+		return 0;
+
+	/* map the next page */
+	io_ctl_map_page(io_ctl, 1);
+	return 0;
+}
+
+static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
+{
+	if (!io_ctl->cur)
+		return -ENOSPC;
+
+	/*
+	 * If we aren't at the start of the current page, unmap this one and
+	 * map the next one if there is any left.
+	 */
+	if (io_ctl->cur != io_ctl->orig) {
+		io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+		if (io_ctl->index >= io_ctl->num_pages)
+			return -ENOSPC;
+		io_ctl_map_page(io_ctl, 0);
+	}
+
+	memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
+	io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+	if (io_ctl->index < io_ctl->num_pages)
+		io_ctl_map_page(io_ctl, 0);
+	return 0;
+}
+
+static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
+{
+	/*
+	 * If we're not on the boundary we know we've modified the page and we
+	 * need to crc the page.
+	 */
+	if (io_ctl->cur != io_ctl->orig)
+		io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+	else
+		io_ctl_unmap_page(io_ctl);
+
+	while (io_ctl->index < io_ctl->num_pages) {
+		io_ctl_map_page(io_ctl, 1);
+		io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+	}
+}
+
+static int io_ctl_read_entry(struct io_ctl *io_ctl,
+			    struct btrfs_free_space *entry, u8 *type)
+{
+	struct btrfs_free_space_entry *e;
+
+	e = io_ctl->cur;
+	entry->offset = le64_to_cpu(e->offset);
+	entry->bytes = le64_to_cpu(e->bytes);
+	*type = e->type;
+	io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+	io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+	if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+		return 0;
+
+	io_ctl_unmap_page(io_ctl);
+
+	if (io_ctl->index >= io_ctl->num_pages)
+		return 0;
+
+	return io_ctl_check_crc(io_ctl, io_ctl->index);
+}
+
+static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
+			      struct btrfs_free_space *entry)
+{
+	int ret;
+
+	if (io_ctl->cur && io_ctl->cur != io_ctl->orig)
+		io_ctl_unmap_page(io_ctl);
+
+	ret = io_ctl_check_crc(io_ctl, io_ctl->index);
+	if (ret)
+		return ret;
+
+	memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
+	io_ctl_unmap_page(io_ctl);
+
+	return 0;
+}
+
 int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 			    struct btrfs_free_space_ctl *ctl,
 			    struct btrfs_path *path, u64 offset)
 {
 	struct btrfs_free_space_header *header;
 	struct extent_buffer *leaf;
-	struct page *page;
+	struct io_ctl io_ctl;
 	struct btrfs_key key;
+	struct btrfs_free_space *e, *n;
 	struct list_head bitmaps;
 	u64 num_entries;
 	u64 num_bitmaps;
 	u64 generation;
-	pgoff_t index = 0;
+	u8 type;
 	int ret = 0;
 
 	INIT_LIST_HEAD(&bitmaps);
 
 	/* Nothing in the space cache, goodbye */
 	if (!i_size_read(inode))
-		goto out;
+		return 0;
 
 	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
 	key.offset = offset;
@@ -269,11 +590,10 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
-		goto out;
+		return 0;
 	else if (ret > 0) {
 		btrfs_release_path(path);
-		ret = 0;
-		goto out;
+		return 0;
 	}
 
 	ret = -1;
@@ -291,169 +611,100 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 		       " not match free space cache generation (%llu)\n",
 		       (unsigned long long)BTRFS_I(inode)->generation,
 		       (unsigned long long)generation);
-		goto out;
+		return 0;
 	}
 
 	if (!num_entries)
-		goto out;
+		return 0;
 
+	io_ctl_init(&io_ctl, inode, root);
 	ret = readahead_cache(inode);
 	if (ret)
 		goto out;
 
-	while (1) {
-		struct btrfs_free_space_entry *entry;
-		struct btrfs_free_space *e;
-		void *addr;
-		unsigned long offset = 0;
-		int need_loop = 0;
+	ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
+	if (ret)
+		goto out;
 
-		if (!num_entries && !num_bitmaps)
-			break;
+	ret = io_ctl_check_crc(&io_ctl, 0);
+	if (ret)
+		goto free_cache;
 
-		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
-		if (!page)
+	ret = io_ctl_check_generation(&io_ctl, generation);
+	if (ret)
+		goto free_cache;
+
+	while (num_entries) {
+		e = kmem_cache_zalloc(btrfs_free_space_cachep,
+				      GFP_NOFS);
+		if (!e)
 			goto free_cache;
 
-		if (!PageUptodate(page)) {
-			btrfs_readpage(NULL, page);
-			lock_page(page);
-			if (!PageUptodate(page)) {
-				unlock_page(page);
-				page_cache_release(page);
-				printk(KERN_ERR "btrfs: error reading free "
-				       "space cache\n");
-				goto free_cache;
-			}
+		ret = io_ctl_read_entry(&io_ctl, e, &type);
+		if (ret) {
+			kmem_cache_free(btrfs_free_space_cachep, e);
+			goto free_cache;
 		}
-		addr = kmap(page);
 
-		if (index == 0) {
-			u64 *gen;
+		if (!e->bytes) {
+			kmem_cache_free(btrfs_free_space_cachep, e);
+			goto free_cache;
+		}
 
-			/*
-			 * We put a bogus crc in the front of the first page in
-			 * case old kernels try to mount a fs with the new
-			 * format to make sure they discard the cache.
-			 */
-			addr += sizeof(u64);
-			offset += sizeof(u64);
-
-			gen = addr;
-			if (*gen != BTRFS_I(inode)->generation) {
-				printk(KERN_ERR "btrfs: space cache generation"
-				       " (%llu) does not match inode (%llu)\n",
-				       (unsigned long long)*gen,
-				       (unsigned long long)
-				       BTRFS_I(inode)->generation);
-				kunmap(page);
-				unlock_page(page);
-				page_cache_release(page);
+		if (type == BTRFS_FREE_SPACE_EXTENT) {
+			spin_lock(&ctl->tree_lock);
+			ret = link_free_space(ctl, e);
+			spin_unlock(&ctl->tree_lock);
+			if (ret) {
+				printk(KERN_ERR "Duplicate entries in "
+				       "free space cache, dumping\n");
+				kmem_cache_free(btrfs_free_space_cachep, e);
 				goto free_cache;
 			}
-			addr += sizeof(u64);
-			offset += sizeof(u64);
-		}
-		entry = addr;
-
-		while (1) {
-			if (!num_entries)
-				break;
-
-			need_loop = 1;
-			e = kmem_cache_zalloc(btrfs_free_space_cachep,
-					      GFP_NOFS);
-			if (!e) {
-				kunmap(page);
-				unlock_page(page);
-				page_cache_release(page);
+		} else {
+			BUG_ON(!num_bitmaps);
+			num_bitmaps--;
+			e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
+			if (!e->bitmap) {
+				kmem_cache_free(
+					btrfs_free_space_cachep, e);
 				goto free_cache;
 			}
-
-			e->offset = le64_to_cpu(entry->offset);
-			e->bytes = le64_to_cpu(entry->bytes);
-			if (!e->bytes) {
-				kunmap(page);
+			spin_lock(&ctl->tree_lock);
+			ret = link_free_space(ctl, e);
+			ctl->total_bitmaps++;
+			ctl->op->recalc_thresholds(ctl);
+			spin_unlock(&ctl->tree_lock);
+			if (ret) {
+				printk(KERN_ERR "Duplicate entries in "
+				       "free space cache, dumping\n");
 				kmem_cache_free(btrfs_free_space_cachep, e);
-				unlock_page(page);
-				page_cache_release(page);
 				goto free_cache;
 			}
-
-			if (entry->type == BTRFS_FREE_SPACE_EXTENT) {
-				spin_lock(&ctl->tree_lock);
-				ret = link_free_space(ctl, e);
-				spin_unlock(&ctl->tree_lock);
-				if (ret) {
-					printk(KERN_ERR "Duplicate entries in "
-					       "free space cache, dumping\n");
-					kunmap(page);
-					unlock_page(page);
-					page_cache_release(page);
-					goto free_cache;
-				}
-			} else {
-				e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
-				if (!e->bitmap) {
-					kunmap(page);
-					kmem_cache_free(
-						btrfs_free_space_cachep, e);
-					unlock_page(page);
-					page_cache_release(page);
-					goto free_cache;
-				}
-				spin_lock(&ctl->tree_lock);
-				ret = link_free_space(ctl, e);
-				ctl->total_bitmaps++;
-				ctl->op->recalc_thresholds(ctl);
-				spin_unlock(&ctl->tree_lock);
-				if (ret) {
-					printk(KERN_ERR "Duplicate entries in "
-					       "free space cache, dumping\n");
-					kunmap(page);
-					unlock_page(page);
-					page_cache_release(page);
-					goto free_cache;
-				}
-				list_add_tail(&e->list, &bitmaps);
-			}
-
-			num_entries--;
-			offset += sizeof(struct btrfs_free_space_entry);
-			if (offset + sizeof(struct btrfs_free_space_entry) >=
-			    PAGE_CACHE_SIZE)
-				break;
-			entry++;
+			list_add_tail(&e->list, &bitmaps);
 		}
 
-		/*
-		 * We read an entry out of this page, we need to move on to the
-		 * next page.
-		 */
-		if (need_loop) {
-			kunmap(page);
-			goto next;
-		}
+		num_entries--;
+	}
 
-		/*
-		 * We add the bitmaps at the end of the entries in order that
-		 * the bitmap entries are added to the cache.
-		 */
-		e = list_entry(bitmaps.next, struct btrfs_free_space, list);
+	/*
+	 * We add the bitmaps at the end of the entries in order that
+	 * the bitmap entries are added to the cache.
+	 */
+	list_for_each_entry_safe(e, n, &bitmaps, list) {
 		list_del_init(&e->list);
-		memcpy(e->bitmap, addr, PAGE_CACHE_SIZE);
-		kunmap(page);
-		num_bitmaps--;
-next:
-		unlock_page(page);
-		page_cache_release(page);
-		index++;
+		ret = io_ctl_read_bitmap(&io_ctl, e);
+		if (ret)
+			goto free_cache;
 	}
 
+	io_ctl_drop_pages(&io_ctl);
 	ret = 1;
 out:
+	io_ctl_free(&io_ctl);
 	return ret;
 free_cache:
+	io_ctl_drop_pages(&io_ctl);
 	__btrfs_remove_free_space_cache(ctl);
 	goto out;
 }
@@ -465,7 +716,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
 	struct btrfs_root *root = fs_info->tree_root;
 	struct inode *inode;
 	struct btrfs_path *path;
-	int ret;
+	int ret = 0;
 	bool matched;
 	u64 used = btrfs_block_group_used(&block_group->item);
 
@@ -497,6 +748,14 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
 		return 0;
 	}
 
+	/* We may have converted the inode and made the cache invalid. */
+	spin_lock(&block_group->lock);
+	if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
+		spin_unlock(&block_group->lock);
+		goto out;
+	}
+	spin_unlock(&block_group->lock);
+
 	ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
 				      path, block_group->key.objectid);
 	btrfs_free_path(path);
@@ -530,6 +789,19 @@ out:
 	return ret;
 }
 
+/**
+ * __btrfs_write_out_cache - write out cached info to an inode
+ * @root - the root the inode belongs to
+ * @ctl - the free space cache we are going to write out
+ * @block_group - the block_group for this cache if it belongs to a block_group
+ * @trans - the trans handle
+ * @path - the path to use
+ * @offset - the offset for the key we'll insert
+ *
+ * This function writes out a free space cache struct to disk for quick recovery
+ * on mount.  This will return 0 if it was successfull in writing the cache out,
+ * and -1 if it was not.
+ */
 int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 			    struct btrfs_free_space_ctl *ctl,
 			    struct btrfs_block_group_cache *block_group,
@@ -540,42 +812,24 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	struct extent_buffer *leaf;
 	struct rb_node *node;
 	struct list_head *pos, *n;
-	struct page **pages;
-	struct page *page;
 	struct extent_state *cached_state = NULL;
 	struct btrfs_free_cluster *cluster = NULL;
 	struct extent_io_tree *unpin = NULL;
+	struct io_ctl io_ctl;
 	struct list_head bitmap_list;
 	struct btrfs_key key;
 	u64 start, end, len;
-	u64 bytes = 0;
-	u32 crc = ~(u32)0;
-	int index = 0, num_pages = 0;
 	int entries = 0;
 	int bitmaps = 0;
-	int ret = -1;
-	bool next_page = false;
-	bool out_of_space = false;
+	int ret;
+	int err = -1;
 
 	INIT_LIST_HEAD(&bitmap_list);
 
-	node = rb_first(&ctl->free_space_offset);
-	if (!node)
-		return 0;
-
 	if (!i_size_read(inode))
 		return -1;
 
-	num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
-		PAGE_CACHE_SHIFT;
-
-	filemap_write_and_wait(inode->i_mapping);
-	btrfs_wait_ordered_range(inode, inode->i_size &
-				 ~(root->sectorsize - 1), (u64)-1);
-
-	pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
-	if (!pages)
-		return -1;
+	io_ctl_init(&io_ctl, inode, root);
 
 	/* Get the cluster for this block_group if it exists */
 	if (block_group && !list_empty(&block_group->cluster_list))
@@ -589,30 +843,9 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	 */
 	unpin = root->fs_info->pinned_extents;
 
-	/*
-	 * Lock all pages first so we can lock the extent safely.
-	 *
-	 * NOTE: Because we hold the ref the entire time we're going to write to
-	 * the page find_get_page should never fail, so we don't do a check
-	 * after find_get_page at this point.  Just putting this here so people
-	 * know and don't freak out.
-	 */
-	while (index < num_pages) {
-		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
-		if (!page) {
-			int i;
-
-			for (i = 0; i < num_pages; i++) {
-				unlock_page(pages[i]);
-				page_cache_release(pages[i]);
-			}
-			goto out;
-		}
-		pages[index] = page;
-		index++;
-	}
+	/* Lock all pages first so we can lock the extent safely. */
+	io_ctl_prepare_pages(&io_ctl, inode, 0);
 
-	index = 0;
 	lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
 			 0, &cached_state, GFP_NOFS);
 
@@ -623,189 +856,111 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	if (block_group)
 		start = block_group->key.objectid;
 
-	/* Write out the extent entries */
-	do {
-		struct btrfs_free_space_entry *entry;
-		void *addr, *orig;
-		unsigned long offset = 0;
+	node = rb_first(&ctl->free_space_offset);
+	if (!node && cluster) {
+		node = rb_first(&cluster->root);
+		cluster = NULL;
+	}
 
-		next_page = false;
+	/* Make sure we can fit our crcs into the first page */
+	if (io_ctl.check_crcs &&
+	    (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) {
+		WARN_ON(1);
+		goto out_nospc;
+	}
 
-		if (index >= num_pages) {
-			out_of_space = true;
-			break;
-		}
+	io_ctl_set_generation(&io_ctl, trans->transid);
 
-		page = pages[index];
+	/* Write out the extent entries */
+	while (node) {
+		struct btrfs_free_space *e;
 
-		orig = addr = kmap(page);
-		if (index == 0) {
-			u64 *gen;
+		e = rb_entry(node, struct btrfs_free_space, offset_index);
+		entries++;
 
-			/*
-			 * We're going to put in a bogus crc for this page to
-			 * make sure that old kernels who aren't aware of this
-			 * format will be sure to discard the cache.
-			 */
-			addr += sizeof(u64);
-			offset += sizeof(u64);
+		ret = io_ctl_add_entry(&io_ctl, e->offset, e->bytes,
+				       e->bitmap);
+		if (ret)
+			goto out_nospc;
 
-			gen = addr;
-			*gen = trans->transid;
-			addr += sizeof(u64);
-			offset += sizeof(u64);
+		if (e->bitmap) {
+			list_add_tail(&e->list, &bitmap_list);
+			bitmaps++;
 		}
-		entry = addr;
-
-		memset(addr, 0, PAGE_CACHE_SIZE - offset);
-		while (node && !next_page) {
-			struct btrfs_free_space *e;
-
-			e = rb_entry(node, struct btrfs_free_space, offset_index);
-			entries++;
-
-			entry->offset = cpu_to_le64(e->offset);
-			entry->bytes = cpu_to_le64(e->bytes);
-			if (e->bitmap) {
-				entry->type = BTRFS_FREE_SPACE_BITMAP;
-				list_add_tail(&e->list, &bitmap_list);
-				bitmaps++;
-			} else {
-				entry->type = BTRFS_FREE_SPACE_EXTENT;
-			}
-			node = rb_next(node);
-			if (!node && cluster) {
-				node = rb_first(&cluster->root);
-				cluster = NULL;
-			}
-			offset += sizeof(struct btrfs_free_space_entry);
-			if (offset + sizeof(struct btrfs_free_space_entry) >=
-			    PAGE_CACHE_SIZE)
-				next_page = true;
-			entry++;
+		node = rb_next(node);
+		if (!node && cluster) {
+			node = rb_first(&cluster->root);
+			cluster = NULL;
 		}
+	}
 
-		/*
-		 * We want to add any pinned extents to our free space cache
-		 * so we don't leak the space
-		 */
-		while (block_group && !next_page &&
-		       (start < block_group->key.objectid +
-			block_group->key.offset)) {
-			ret = find_first_extent_bit(unpin, start, &start, &end,
-						    EXTENT_DIRTY);
-			if (ret) {
-				ret = 0;
-				break;
-			}
-
-			/* This pinned extent is out of our range */
-			if (start >= block_group->key.objectid +
-			    block_group->key.offset)
-				break;
-
-			len = block_group->key.objectid +
-				block_group->key.offset - start;
-			len = min(len, end + 1 - start);
-
-			entries++;
-			entry->offset = cpu_to_le64(start);
-			entry->bytes = cpu_to_le64(len);
-			entry->type = BTRFS_FREE_SPACE_EXTENT;
-
-			start = end + 1;
-			offset += sizeof(struct btrfs_free_space_entry);
-			if (offset + sizeof(struct btrfs_free_space_entry) >=
-			    PAGE_CACHE_SIZE)
-				next_page = true;
-			entry++;
+	/*
+	 * We want to add any pinned extents to our free space cache
+	 * so we don't leak the space
+	 */
+	while (block_group && (start < block_group->key.objectid +
+			       block_group->key.offset)) {
+		ret = find_first_extent_bit(unpin, start, &start, &end,
+					    EXTENT_DIRTY);
+		if (ret) {
+			ret = 0;
+			break;
 		}
 
-		/* Generate bogus crc value */
-		if (index == 0) {
-			u32 *tmp;
-			crc = btrfs_csum_data(root, orig + sizeof(u64), crc,
-					      PAGE_CACHE_SIZE - sizeof(u64));
-			btrfs_csum_final(crc, (char *)&crc);
-			crc++;
-			tmp = orig;
-			*tmp = crc;
-		}
+		/* This pinned extent is out of our range */
+		if (start >= block_group->key.objectid +
+		    block_group->key.offset)
+			break;
 
-		kunmap(page);
+		len = block_group->key.objectid +
+			block_group->key.offset - start;
+		len = min(len, end + 1 - start);
 
-		bytes += PAGE_CACHE_SIZE;
+		entries++;
+		ret = io_ctl_add_entry(&io_ctl, start, len, NULL);
+		if (ret)
+			goto out_nospc;
 
-		index++;
-	} while (node || next_page);
+		start = end + 1;
+	}
 
 	/* Write out the bitmaps */
 	list_for_each_safe(pos, n, &bitmap_list) {
-		void *addr;
 		struct btrfs_free_space *entry =
 			list_entry(pos, struct btrfs_free_space, list);
 
-		if (index >= num_pages) {
-			out_of_space = true;
-			break;
-		}
-		page = pages[index];
-
-		addr = kmap(page);
-		memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE);
-		kunmap(page);
-		bytes += PAGE_CACHE_SIZE;
-
+		ret = io_ctl_add_bitmap(&io_ctl, entry->bitmap);
+		if (ret)
+			goto out_nospc;
 		list_del_init(&entry->list);
-		index++;
-	}
-
-	if (out_of_space) {
-		btrfs_drop_pages(pages, num_pages);
-		unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
-				     i_size_read(inode) - 1, &cached_state,
-				     GFP_NOFS);
-		ret = 0;
-		goto out;
 	}
 
 	/* Zero out the rest of the pages just to make sure */
-	while (index < num_pages) {
-		void *addr;
+	io_ctl_zero_remaining_pages(&io_ctl);
 
-		page = pages[index];
-		addr = kmap(page);
-		memset(addr, 0, PAGE_CACHE_SIZE);
-		kunmap(page);
-		bytes += PAGE_CACHE_SIZE;
-		index++;
-	}
-
-	ret = btrfs_dirty_pages(root, inode, pages, num_pages, 0,
-					    bytes, &cached_state);
-	btrfs_drop_pages(pages, num_pages);
+	ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
+				0, i_size_read(inode), &cached_state);
+	io_ctl_drop_pages(&io_ctl);
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
 			     i_size_read(inode) - 1, &cached_state, GFP_NOFS);
 
-	if (ret) {
-		ret = 0;
+	if (ret)
 		goto out;
-	}
 
-	BTRFS_I(inode)->generation = trans->transid;
 
-	filemap_write_and_wait(inode->i_mapping);
+	ret = filemap_write_and_wait(inode->i_mapping);
+	if (ret)
+		goto out;
 
 	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
 	key.offset = offset;
 	key.type = 0;
 
-	ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
+	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 	if (ret < 0) {
-		ret = -1;
-		clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
-				 EXTENT_DIRTY | EXTENT_DELALLOC |
-				 EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS);
+		clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
+				 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
+				 GFP_NOFS);
 		goto out;
 	}
 	leaf = path->nodes[0];
@@ -816,15 +971,16 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 		if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
 		    found_key.offset != offset) {
-			ret = -1;
-			clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
-					 EXTENT_DIRTY | EXTENT_DELALLOC |
-					 EXTENT_DO_ACCOUNTING, 0, 0, NULL,
-					 GFP_NOFS);
+			clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
+					 inode->i_size - 1,
+					 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
+					 NULL, GFP_NOFS);
 			btrfs_release_path(path);
 			goto out;
 		}
 	}
+
+	BTRFS_I(inode)->generation = trans->transid;
 	header = btrfs_item_ptr(leaf, path->slots[0],
 				struct btrfs_free_space_header);
 	btrfs_set_free_space_entries(leaf, header, entries);
@@ -833,16 +989,26 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_release_path(path);
 
-	ret = 1;
-
+	err = 0;
 out:
-	kfree(pages);
-	if (ret != 1) {
-		invalidate_inode_pages2_range(inode->i_mapping, 0, index);
+	io_ctl_free(&io_ctl);
+	if (err) {
+		invalidate_inode_pages2(inode->i_mapping);
 		BTRFS_I(inode)->generation = 0;
 	}
 	btrfs_update_inode(trans, root, inode);
-	return ret;
+	return err;
+
+out_nospc:
+	list_for_each_safe(pos, n, &bitmap_list) {
+		struct btrfs_free_space *entry =
+			list_entry(pos, struct btrfs_free_space, list);
+		list_del_init(&entry->list);
+	}
+	io_ctl_drop_pages(&io_ctl);
+	unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+			     i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+	goto out;
 }
 
 int btrfs_write_out_cache(struct btrfs_root *root,
@@ -869,14 +1035,15 @@ int btrfs_write_out_cache(struct btrfs_root *root,
 
 	ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
 				      path, block_group->key.objectid);
-	if (ret < 0) {
+	if (ret) {
 		spin_lock(&block_group->lock);
 		block_group->disk_cache_state = BTRFS_DC_ERROR;
 		spin_unlock(&block_group->lock);
 		ret = 0;
-
+#ifdef DEBUG
 		printk(KERN_ERR "btrfs: failed to write free space cace "
 		       "for block group %llu\n", block_group->key.objectid);
+#endif
 	}
 
 	iput(inode);
@@ -2472,9 +2639,19 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
 		spin_unlock(&ctl->tree_lock);
 
 		if (bytes >= minlen) {
-			int update_ret;
-			update_ret = btrfs_update_reserved_bytes(block_group,
-								 bytes, 1, 1);
+			struct btrfs_space_info *space_info;
+			int update = 0;
+
+			space_info = block_group->space_info;
+			spin_lock(&space_info->lock);
+			spin_lock(&block_group->lock);
+			if (!block_group->ro) {
+				block_group->reserved += bytes;
+				space_info->bytes_reserved += bytes;
+				update = 1;
+			}
+			spin_unlock(&block_group->lock);
+			spin_unlock(&space_info->lock);
 
 			ret = btrfs_error_discard_extent(fs_info->extent_root,
 							 start,
@@ -2482,9 +2659,16 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
 							 &actually_trimmed);
 
 			btrfs_add_free_space(block_group, start, bytes);
-			if (!update_ret)
-				btrfs_update_reserved_bytes(block_group,
-							    bytes, 0, 1);
+			if (update) {
+				spin_lock(&space_info->lock);
+				spin_lock(&block_group->lock);
+				if (block_group->ro)
+					space_info->bytes_readonly += bytes;
+				block_group->reserved -= bytes;
+				space_info->bytes_reserved -= bytes;
+				spin_unlock(&space_info->lock);
+				spin_unlock(&block_group->lock);
+			}
 
 			if (ret)
 				break;
@@ -2643,9 +2827,13 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
 		return 0;
 
 	ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
-	if (ret < 0)
+	if (ret) {
+		btrfs_delalloc_release_metadata(inode, inode->i_size);
+#ifdef DEBUG
 		printk(KERN_ERR "btrfs: failed to write free ino cache "
 		       "for root %llu\n", root->root_key.objectid);
+#endif
+	}
 
 	iput(inode);
 	return ret;
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index b4087e0fa87..53dcbdf446c 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -465,14 +465,16 @@ again:
 	/* Just to make sure we have enough space */
 	prealloc += 8 * PAGE_CACHE_SIZE;
 
-	ret = btrfs_check_data_free_space(inode, prealloc);
+	ret = btrfs_delalloc_reserve_space(inode, prealloc);
 	if (ret)
 		goto out_put;
 
 	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc,
 					      prealloc, prealloc, &alloc_hint);
-	if (ret)
+	if (ret) {
+		btrfs_delalloc_release_space(inode, prealloc);
 		goto out_put;
+	}
 	btrfs_free_reserved_data_space(inode, prealloc);
 
 out_put:
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b2d004ad66a..f12747c9447 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1792,12 +1792,12 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 	}
 	ret = 0;
 out:
-	if (nolock) {
-		if (trans)
-			btrfs_end_transaction_nolock(trans, root);
-	} else {
+	if (root != root->fs_info->tree_root)
 		btrfs_delalloc_release_metadata(inode, ordered_extent->len);
-		if (trans)
+	if (trans) {
+		if (nolock)
+			btrfs_end_transaction_nolock(trans, root);
+		else
 			btrfs_end_transaction(trans, root);
 	}
 
@@ -2079,89 +2079,6 @@ void btrfs_run_delayed_iputs(struct btrfs_root *root)
 	up_read(&root->fs_info->cleanup_work_sem);
 }
 
-/*
- * calculate extra metadata reservation when snapshotting a subvolume
- * contains orphan files.
- */
-void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
-				struct btrfs_pending_snapshot *pending,
-				u64 *bytes_to_reserve)
-{
-	struct btrfs_root *root;
-	struct btrfs_block_rsv *block_rsv;
-	u64 num_bytes;
-	int index;
-
-	root = pending->root;
-	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
-		return;
-
-	block_rsv = root->orphan_block_rsv;
-
-	/* orphan block reservation for the snapshot */
-	num_bytes = block_rsv->size;
-
-	/*
-	 * after the snapshot is created, COWing tree blocks may use more
-	 * space than it frees. So we should make sure there is enough
-	 * reserved space.
-	 */
-	index = trans->transid & 0x1;
-	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
-		num_bytes += block_rsv->size -
-			     (block_rsv->reserved + block_rsv->freed[index]);
-	}
-
-	*bytes_to_reserve += num_bytes;
-}
-
-void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
-				struct btrfs_pending_snapshot *pending)
-{
-	struct btrfs_root *root = pending->root;
-	struct btrfs_root *snap = pending->snap;
-	struct btrfs_block_rsv *block_rsv;
-	u64 num_bytes;
-	int index;
-	int ret;
-
-	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
-		return;
-
-	/* refill source subvolume's orphan block reservation */
-	block_rsv = root->orphan_block_rsv;
-	index = trans->transid & 0x1;
-	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
-		num_bytes = block_rsv->size -
-			    (block_rsv->reserved + block_rsv->freed[index]);
-		ret = btrfs_block_rsv_migrate(&pending->block_rsv,
-					      root->orphan_block_rsv,
-					      num_bytes);
-		BUG_ON(ret);
-	}
-
-	/* setup orphan block reservation for the snapshot */
-	block_rsv = btrfs_alloc_block_rsv(snap);
-	BUG_ON(!block_rsv);
-
-	btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
-	snap->orphan_block_rsv = block_rsv;
-
-	num_bytes = root->orphan_block_rsv->size;
-	ret = btrfs_block_rsv_migrate(&pending->block_rsv,
-				      block_rsv, num_bytes);
-	BUG_ON(ret);
-
-#if 0
-	/* insert orphan item for the snapshot */
-	WARN_ON(!root->orphan_item_inserted);
-	ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
-				       snap->root_key.objectid);
-	BUG_ON(ret);
-	snap->orphan_item_inserted = 1;
-#endif
-}
-
 enum btrfs_orphan_cleanup_state {
 	ORPHAN_CLEANUP_STARTED	= 1,
 	ORPHAN_CLEANUP_DONE	= 2,
@@ -2247,9 +2164,6 @@ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
 	}
 	spin_unlock(&root->orphan_lock);
 
-	if (block_rsv)
-		btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
-
 	/* grab metadata reservation from transaction handle */
 	if (reserve) {
 		ret = btrfs_orphan_reserve_metadata(trans, inode);
@@ -2316,6 +2230,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 	struct btrfs_key key, found_key;
 	struct btrfs_trans_handle *trans;
 	struct inode *inode;
+	u64 last_objectid = 0;
 	int ret = 0, nr_unlink = 0, nr_truncate = 0;
 
 	if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
@@ -2367,41 +2282,49 @@ int btrfs_orphan_cleanup(struct btrfs_root *root)
 		 * crossing root thing.  we store the inode number in the
 		 * offset of the orphan item.
 		 */
+
+		if (found_key.offset == last_objectid) {
+			printk(KERN_ERR "btrfs: Error removing orphan entry, "
+			       "stopping orphan cleanup\n");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		last_objectid = found_key.offset;
+
 		found_key.objectid = found_key.offset;
 		found_key.type = BTRFS_INODE_ITEM_KEY;
 		found_key.offset = 0;
 		inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
-		if (IS_ERR(inode)) {
-			ret = PTR_ERR(inode);
+		ret = PTR_RET(inode);
+		if (ret && ret != -ESTALE)
 			goto out;
-		}
-
-		/*
-		 * add this inode to the orphan list so btrfs_orphan_del does
-		 * the proper thing when we hit it
-		 */
-		spin_lock(&root->orphan_lock);
-		list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
-		spin_unlock(&root->orphan_lock);
 
 		/*
-		 * if this is a bad inode, means we actually succeeded in
-		 * removing the inode, but not the orphan record, which means
-		 * we need to manually delete the orphan since iput will just
-		 * do a destroy_inode
+		 * Inode is already gone but the orphan item is still there,
+		 * kill the orphan item.
 		 */
-		if (is_bad_inode(inode)) {
-			trans = btrfs_start_transaction(root, 0);
+		if (ret == -ESTALE) {
+			trans = btrfs_start_transaction(root, 1);
 			if (IS_ERR(trans)) {
 				ret = PTR_ERR(trans);
 				goto out;
 			}
-			btrfs_orphan_del(trans, inode);
+			ret = btrfs_del_orphan_item(trans, root,
+						    found_key.objectid);
+			BUG_ON(ret);
 			btrfs_end_transaction(trans, root);
-			iput(inode);
 			continue;
 		}
 
+		/*
+		 * add this inode to the orphan list so btrfs_orphan_del does
+		 * the proper thing when we hit it
+		 */
+		spin_lock(&root->orphan_lock);
+		list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
+		spin_unlock(&root->orphan_lock);
+
 		/* if we have links, this was a truncate, lets do that */
 		if (inode->i_nlink) {
 			if (!S_ISREG(inode->i_mode)) {
@@ -2835,7 +2758,16 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 	u64 ino = btrfs_ino(inode);
 	u64 dir_ino = btrfs_ino(dir);
 
-	trans = btrfs_start_transaction(root, 10);
+	/*
+	 * 1 for the possible orphan item
+	 * 1 for the dir item
+	 * 1 for the dir index
+	 * 1 for the inode ref
+	 * 1 for the inode ref in the tree log
+	 * 2 for the dir entries in the log
+	 * 1 for the inode
+	 */
+	trans = btrfs_start_transaction(root, 8);
 	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
 		return trans;
 
@@ -2858,7 +2790,8 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 		return ERR_PTR(-ENOMEM);
 	}
 
-	trans = btrfs_start_transaction(root, 0);
+	/* 1 for the orphan item */
+	trans = btrfs_start_transaction(root, 1);
 	if (IS_ERR(trans)) {
 		btrfs_free_path(path);
 		root->fs_info->enospc_unlink = 0;
@@ -2963,6 +2896,12 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
 	err = 0;
 out:
 	btrfs_free_path(path);
+	/* Migrate the orphan reservation over */
+	if (!err)
+		err = btrfs_block_rsv_migrate(trans->block_rsv,
+				&root->fs_info->global_block_rsv,
+				btrfs_calc_trans_metadata_size(root, 1));
+
 	if (err) {
 		btrfs_end_transaction(trans, root);
 		root->fs_info->enospc_unlink = 0;
@@ -3368,6 +3307,7 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 	pgoff_t index = from >> PAGE_CACHE_SHIFT;
 	unsigned offset = from & (PAGE_CACHE_SIZE-1);
 	struct page *page;
+	gfp_t mask = btrfs_alloc_write_mask(mapping);
 	int ret = 0;
 	u64 page_start;
 	u64 page_end;
@@ -3380,7 +3320,7 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 
 	ret = -ENOMEM;
 again:
-	page = find_or_create_page(mapping, index, GFP_NOFS);
+	page = find_or_create_page(mapping, index, mask);
 	if (!page) {
 		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 		goto out;
@@ -3613,6 +3553,8 @@ void btrfs_evict_inode(struct inode *inode)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_block_rsv *rsv, *global_rsv;
+	u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
 	unsigned long nr;
 	int ret;
 
@@ -3640,22 +3582,55 @@ void btrfs_evict_inode(struct inode *inode)
 		goto no_delete;
 	}
 
+	rsv = btrfs_alloc_block_rsv(root);
+	if (!rsv) {
+		btrfs_orphan_del(NULL, inode);
+		goto no_delete;
+	}
+	rsv->size = min_size;
+	global_rsv = &root->fs_info->global_block_rsv;
+
 	btrfs_i_size_write(inode, 0);
 
+	/*
+	 * This is a bit simpler than btrfs_truncate since
+	 *
+	 * 1) We've already reserved our space for our orphan item in the
+	 *    unlink.
+	 * 2) We're going to delete the inode item, so we don't need to update
+	 *    it at all.
+	 *
+	 * So we just need to reserve some slack space in case we add bytes when
+	 * doing the truncate.
+	 */
 	while (1) {
-		trans = btrfs_join_transaction(root);
-		BUG_ON(IS_ERR(trans));
-		trans->block_rsv = root->orphan_block_rsv;
+		ret = btrfs_block_rsv_refill(root, rsv, min_size);
+
+		/*
+		 * Try and steal from the global reserve since we will
+		 * likely not use this space anyway, we want to try as
+		 * hard as possible to get this to work.
+		 */
+		if (ret)
+			ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
 
-		ret = btrfs_block_rsv_check(trans, root,
-					    root->orphan_block_rsv, 0, 5);
 		if (ret) {
-			BUG_ON(ret != -EAGAIN);
-			ret = btrfs_commit_transaction(trans, root);
-			BUG_ON(ret);
-			continue;
+			printk(KERN_WARNING "Could not get space for a "
+			       "delete, will truncate on mount %d\n", ret);
+			btrfs_orphan_del(NULL, inode);
+			btrfs_free_block_rsv(root, rsv);
+			goto no_delete;
+		}
+
+		trans = btrfs_start_transaction(root, 0);
+		if (IS_ERR(trans)) {
+			btrfs_orphan_del(NULL, inode);
+			btrfs_free_block_rsv(root, rsv);
+			goto no_delete;
 		}
 
+		trans->block_rsv = rsv;
+
 		ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
 		if (ret != -EAGAIN)
 			break;
@@ -3664,14 +3639,17 @@ void btrfs_evict_inode(struct inode *inode)
 		btrfs_end_transaction(trans, root);
 		trans = NULL;
 		btrfs_btree_balance_dirty(root, nr);
-
 	}
 
+	btrfs_free_block_rsv(root, rsv);
+
 	if (ret == 0) {
+		trans->block_rsv = root->orphan_block_rsv;
 		ret = btrfs_orphan_del(trans, inode);
 		BUG_ON(ret);
 	}
 
+	trans->block_rsv = &root->fs_info->trans_block_rsv;
 	if (!(root == root->fs_info->tree_root ||
 	      root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
 		btrfs_return_ino(root, btrfs_ino(inode));
@@ -6541,6 +6519,7 @@ static int btrfs_truncate(struct inode *inode)
 	struct btrfs_trans_handle *trans;
 	unsigned long nr;
 	u64 mask = root->sectorsize - 1;
+	u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
 
 	ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
 	if (ret)
@@ -6588,19 +6567,23 @@ static int btrfs_truncate(struct inode *inode)
 	rsv = btrfs_alloc_block_rsv(root);
 	if (!rsv)
 		return -ENOMEM;
-	btrfs_add_durable_block_rsv(root->fs_info, rsv);
+	rsv->size = min_size;
 
+	/*
+	 * 1 for the truncate slack space
+	 * 1 for the orphan item we're going to add
+	 * 1 for the orphan item deletion
+	 * 1 for updating the inode.
+	 */
 	trans = btrfs_start_transaction(root, 4);
 	if (IS_ERR(trans)) {
 		err = PTR_ERR(trans);
 		goto out;
 	}
 
-	/*
-	 * Reserve space for the truncate process.  Truncate should be adding
-	 * space, but if there are snapshots it may end up using space.
-	 */
-	ret = btrfs_truncate_reserve_metadata(trans, root, rsv);
+	/* Migrate the slack space for the truncate to our reserve */
+	ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
+				      min_size);
 	BUG_ON(ret);
 
 	ret = btrfs_orphan_add(trans, inode);
@@ -6609,21 +6592,6 @@ static int btrfs_truncate(struct inode *inode)
 		goto out;
 	}
 
-	nr = trans->blocks_used;
-	btrfs_end_transaction(trans, root);
-	btrfs_btree_balance_dirty(root, nr);
-
-	/*
-	 * Ok so we've already migrated our bytes over for the truncate, so here
-	 * just reserve the one slot we need for updating the inode.
-	 */
-	trans = btrfs_start_transaction(root, 1);
-	if (IS_ERR(trans)) {
-		err = PTR_ERR(trans);
-		goto out;
-	}
-	trans->block_rsv = rsv;
-
 	/*
 	 * setattr is responsible for setting the ordered_data_close flag,
 	 * but that is only tested during the last file release.  That
@@ -6645,20 +6613,30 @@ static int btrfs_truncate(struct inode *inode)
 		btrfs_add_ordered_operation(trans, root, inode);
 
 	while (1) {
+		ret = btrfs_block_rsv_refill(root, rsv, min_size);
+		if (ret) {
+			/*
+			 * This can only happen with the original transaction we
+			 * started above, every other time we shouldn't have a
+			 * transaction started yet.
+			 */
+			if (ret == -EAGAIN)
+				goto end_trans;
+			err = ret;
+			break;
+		}
+
 		if (!trans) {
-			trans = btrfs_start_transaction(root, 3);
+			/* Just need the 1 for updating the inode */
+			trans = btrfs_start_transaction(root, 1);
 			if (IS_ERR(trans)) {
 				err = PTR_ERR(trans);
 				goto out;
 			}
-
-			ret = btrfs_truncate_reserve_metadata(trans, root,
-							      rsv);
-			BUG_ON(ret);
-
-			trans->block_rsv = rsv;
 		}
 
+		trans->block_rsv = rsv;
+
 		ret = btrfs_truncate_inode_items(trans, root, inode,
 						 inode->i_size,
 						 BTRFS_EXTENT_DATA_KEY);
@@ -6673,7 +6651,7 @@ static int btrfs_truncate(struct inode *inode)
 			err = ret;
 			break;
 		}
-
+end_trans:
 		nr = trans->blocks_used;
 		btrfs_end_transaction(trans, root);
 		trans = NULL;
@@ -6755,9 +6733,9 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	ei->last_sub_trans = 0;
 	ei->logged_trans = 0;
 	ei->delalloc_bytes = 0;
-	ei->reserved_bytes = 0;
 	ei->disk_i_size = 0;
 	ei->flags = 0;
+	ei->csum_bytes = 0;
 	ei->index_cnt = (u64)-1;
 	ei->last_unlink_trans = 0;
 
@@ -6803,6 +6781,8 @@ void btrfs_destroy_inode(struct inode *inode)
 	WARN_ON(inode->i_data.nrpages);
 	WARN_ON(BTRFS_I(inode)->outstanding_extents);
 	WARN_ON(BTRFS_I(inode)->reserved_extents);
+	WARN_ON(BTRFS_I(inode)->delalloc_bytes);
+	WARN_ON(BTRFS_I(inode)->csum_bytes);
 
 	/*
 	 * This can happen where we create an inode, but somebody else also
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index dae5dfe41ba..877727b28d8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -117,7 +117,7 @@ void btrfs_update_iflags(struct inode *inode)
 /*
  * Inherit flags from the parent inode.
  *
- * Unlike extN we don't have any flags we don't want to inherit currently.
+ * Currently only the compression flags and the cow flags are inherited.
  */
 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 {
@@ -128,12 +128,17 @@ void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 
 	flags = BTRFS_I(dir)->flags;
 
-	if (S_ISREG(inode->i_mode))
-		flags &= ~BTRFS_INODE_DIRSYNC;
-	else if (!S_ISDIR(inode->i_mode))
-		flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
+	if (flags & BTRFS_INODE_NOCOMPRESS) {
+		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
+		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+	} else if (flags & BTRFS_INODE_COMPRESS) {
+		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
+		BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
+	}
+
+	if (flags & BTRFS_INODE_NODATACOW)
+		BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 
-	BTRFS_I(inode)->flags = flags;
 	btrfs_update_iflags(inode);
 }
 
@@ -843,6 +848,7 @@ static int cluster_pages_for_defrag(struct inode *inode,
 	int i_done;
 	struct btrfs_ordered_extent *ordered;
 	struct extent_state *cached_state = NULL;
+	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 
 	if (isize == 0)
 		return 0;
@@ -860,7 +866,7 @@ again:
 	for (i = 0; i < num_pages; i++) {
 		struct page *page;
 		page = find_or_create_page(inode->i_mapping,
-					    start_index + i, GFP_NOFS);
+					    start_index + i, mask);
 		if (!page)
 			break;
 
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 59bb1764273..10af6a0e086 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2041,8 +2041,7 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
 		BUG_ON(IS_ERR(trans));
 		trans->block_rsv = rc->block_rsv;
 
-		ret = btrfs_block_rsv_check(trans, root, rc->block_rsv,
-					    min_reserved, 0);
+		ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved);
 		if (ret) {
 			BUG_ON(ret != -EAGAIN);
 			ret = btrfs_commit_transaction(trans, root);
@@ -2152,8 +2151,7 @@ int prepare_to_merge(struct reloc_control *rc, int err)
 again:
 	if (!err) {
 		num_bytes = rc->merging_rsv_size;
-		ret = btrfs_block_rsv_add(NULL, root, rc->block_rsv,
-					  num_bytes);
+		ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
 		if (ret)
 			err = ret;
 	}
@@ -2427,7 +2425,7 @@ static int reserve_metadata_space(struct btrfs_trans_handle *trans,
 	num_bytes = calcu_metadata_size(rc, node, 1) * 2;
 
 	trans->block_rsv = rc->block_rsv;
-	ret = btrfs_block_rsv_add(trans, root, rc->block_rsv, num_bytes);
+	ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes);
 	if (ret) {
 		if (ret == -EAGAIN)
 			rc->commit_transaction = 1;
@@ -2922,6 +2920,7 @@ static int relocate_file_extent_cluster(struct inode *inode,
 	unsigned long last_index;
 	struct page *page;
 	struct file_ra_state *ra;
+	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 	int nr = 0;
 	int ret = 0;
 
@@ -2956,7 +2955,7 @@ static int relocate_file_extent_cluster(struct inode *inode,
 						  ra, NULL, index,
 						  last_index + 1 - index);
 			page = find_or_create_page(inode->i_mapping, index,
-						   GFP_NOFS);
+						   mask);
 			if (!page) {
 				btrfs_delalloc_release_metadata(inode,
 							PAGE_CACHE_SIZE);
@@ -3645,14 +3644,11 @@ int prepare_to_relocate(struct reloc_control *rc)
 	 * btrfs_init_reloc_root will use them when there
 	 * is no reservation in transaction handle.
 	 */
-	ret = btrfs_block_rsv_add(NULL, rc->extent_root, rc->block_rsv,
+	ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
 				  rc->extent_root->nodesize * 256);
 	if (ret)
 		return ret;
 
-	rc->block_rsv->refill_used = 1;
-	btrfs_add_durable_block_rsv(rc->extent_root->fs_info, rc->block_rsv);
-
 	memset(&rc->cluster, 0, sizeof(rc->cluster));
 	rc->search_start = rc->block_group->key.objectid;
 	rc->extents_found = 0;
@@ -3777,8 +3773,7 @@ restart:
 			}
 		}
 
-		ret = btrfs_block_rsv_check(trans, rc->extent_root,
-					    rc->block_rsv, 0, 5);
+		ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
 		if (ret < 0) {
 			if (ret != -EAGAIN) {
 				err = ret;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 15634d4648d..266d1f35465 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -40,6 +40,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include <linux/cleancache.h>
+#include <linux/mnt_namespace.h>
 #include "compat.h"
 #include "delayed-inode.h"
 #include "ctree.h"
@@ -58,6 +59,7 @@
 #include <trace/events/btrfs.h>
 
 static const struct super_operations btrfs_super_ops;
+static struct file_system_type btrfs_fs_type;
 
 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
 				      char nbuf[16])
@@ -162,7 +164,7 @@ enum {
 	Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 	Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 	Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
-	Opt_inode_cache, Opt_err,
+	Opt_inode_cache, Opt_no_space_cache, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -195,6 +197,7 @@ static match_table_t tokens = {
 	{Opt_subvolrootid, "subvolrootid=%d"},
 	{Opt_defrag, "autodefrag"},
 	{Opt_inode_cache, "inode_cache"},
+	{Opt_no_space_cache, "no_space_cache"},
 	{Opt_err, NULL},
 };
 
@@ -206,14 +209,19 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 {
 	struct btrfs_fs_info *info = root->fs_info;
 	substring_t args[MAX_OPT_ARGS];
-	char *p, *num, *orig;
+	char *p, *num, *orig = NULL;
+	u64 cache_gen;
 	int intarg;
 	int ret = 0;
 	char *compress_type;
 	bool compress_force = false;
 
+	cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
+	if (cache_gen)
+		btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+
 	if (!options)
-		return 0;
+		goto out;
 
 	/*
 	 * strsep changes the string, duplicate it because parse_options
@@ -360,9 +368,12 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 			btrfs_set_opt(info->mount_opt, DISCARD);
 			break;
 		case Opt_space_cache:
-			printk(KERN_INFO "btrfs: enabling disk space caching\n");
 			btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 			break;
+		case Opt_no_space_cache:
+			printk(KERN_INFO "btrfs: disabling disk space caching\n");
+			btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
+			break;
 		case Opt_inode_cache:
 			printk(KERN_INFO "btrfs: enabling inode map caching\n");
 			btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
@@ -391,6 +402,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 		}
 	}
 out:
+	if (!ret && btrfs_test_opt(root, SPACE_CACHE))
+		printk(KERN_INFO "btrfs: disk space caching is enabled\n");
 	kfree(orig);
 	return ret;
 }
@@ -411,7 +424,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
 	int intarg;
 
 	if (!options)
-		goto out;
+		return 0;
 
 	/*
 	 * strsep changes the string, duplicate it because parse_options
@@ -460,26 +473,15 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
 			error = btrfs_scan_one_device(match_strdup(&args[0]),
 					flags, holder, fs_devices);
 			if (error)
-				goto out_free_opts;
+				goto out;
 			break;
 		default:
 			break;
 		}
 	}
 
- out_free_opts:
+out:
 	kfree(orig);
- out:
-	/*
-	 * If no subvolume name is specified we use the default one.  Allocate
-	 * a copy of the string "." here so that code later in the
-	 * mount path doesn't care if it's the default volume or another one.
-	 */
-	if (!*subvol_name) {
-		*subvol_name = kstrdup(".", GFP_KERNEL);
-		if (!*subvol_name)
-			return -ENOMEM;
-	}
 	return error;
 }
 
@@ -492,7 +494,6 @@ static struct dentry *get_default_root(struct super_block *sb,
 	struct btrfs_path *path;
 	struct btrfs_key location;
 	struct inode *inode;
-	struct dentry *dentry;
 	u64 dir_id;
 	int new = 0;
 
@@ -566,29 +567,7 @@ setup_root:
 		return dget(sb->s_root);
 	}
 
-	if (new) {
-		const struct qstr name = { .name = "/", .len = 1 };
-
-		/*
-		 * New inode, we need to make the dentry a sibling of s_root so
-		 * everything gets cleaned up properly on unmount.
-		 */
-		dentry = d_alloc(sb->s_root, &name);
-		if (!dentry) {
-			iput(inode);
-			return ERR_PTR(-ENOMEM);
-		}
-		d_splice_alias(inode, dentry);
-	} else {
-		/*
-		 * We found the inode in cache, just find a dentry for it and
-		 * put the reference to the inode we just got.
-		 */
-		dentry = d_find_alias(inode);
-		iput(inode);
-	}
-
-	return dentry;
+	return d_obtain_alias(inode);
 }
 
 static int btrfs_fill_super(struct super_block *sb,
@@ -719,6 +698,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",noacl");
 	if (btrfs_test_opt(root, SPACE_CACHE))
 		seq_puts(seq, ",space_cache");
+	else
+		seq_puts(seq, ",no_space_cache");
 	if (btrfs_test_opt(root, CLEAR_CACHE))
 		seq_puts(seq, ",clear_cache");
 	if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
@@ -753,6 +734,118 @@ static int btrfs_set_super(struct super_block *s, void *data)
 	return set_anon_super(s, data);
 }
 
+/*
+ * This will strip out the subvol=%s argument for an argument string and add
+ * subvolid=0 to make sure we get the actual tree root for path walking to the
+ * subvol we want.
+ */
+static char *setup_root_args(char *args)
+{
+	unsigned copied = 0;
+	unsigned len = strlen(args) + 2;
+	char *pos;
+	char *ret;
+
+	/*
+	 * We need the same args as before, but minus
+	 *
+	 * subvol=a
+	 *
+	 * and add
+	 *
+	 * subvolid=0
+	 *
+	 * which is a difference of 2 characters, so we allocate strlen(args) +
+	 * 2 characters.
+	 */
+	ret = kzalloc(len * sizeof(char), GFP_NOFS);
+	if (!ret)
+		return NULL;
+	pos = strstr(args, "subvol=");
+
+	/* This shouldn't happen, but just in case.. */
+	if (!pos) {
+		kfree(ret);
+		return NULL;
+	}
+
+	/*
+	 * The subvol=<> arg is not at the front of the string, copy everybody
+	 * up to that into ret.
+	 */
+	if (pos != args) {
+		*pos = '\0';
+		strcpy(ret, args);
+		copied += strlen(args);
+		pos++;
+	}
+
+	strncpy(ret + copied, "subvolid=0", len - copied);
+
+	/* Length of subvolid=0 */
+	copied += 10;
+
+	/*
+	 * If there is no , after the subvol= option then we know there's no
+	 * other options and we can just return.
+	 */
+	pos = strchr(pos, ',');
+	if (!pos)
+		return ret;
+
+	/* Copy the rest of the arguments into our buffer */
+	strncpy(ret + copied, pos, len - copied);
+	copied += strlen(pos);
+
+	return ret;
+}
+
+static struct dentry *mount_subvol(const char *subvol_name, int flags,
+				   const char *device_name, char *data)
+{
+	struct super_block *s;
+	struct dentry *root;
+	struct vfsmount *mnt;
+	struct mnt_namespace *ns_private;
+	char *newargs;
+	struct path path;
+	int error;
+
+	newargs = setup_root_args(data);
+	if (!newargs)
+		return ERR_PTR(-ENOMEM);
+	mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
+			     newargs);
+	kfree(newargs);
+	if (IS_ERR(mnt))
+		return ERR_CAST(mnt);
+
+	ns_private = create_mnt_ns(mnt);
+	if (IS_ERR(ns_private)) {
+		mntput(mnt);
+		return ERR_CAST(ns_private);
+	}
+
+	/*
+	 * This will trigger the automount of the subvol so we can just
+	 * drop the mnt we have here and return the dentry that we
+	 * found.
+	 */
+	error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name,
+				LOOKUP_FOLLOW, &path);
+	put_mnt_ns(ns_private);
+	if (error)
+		return ERR_PTR(error);
+
+	/* Get a ref to the sb and the dentry we found and return it */
+	s = path.mnt->mnt_sb;
+	atomic_inc(&s->s_active);
+	root = dget(path.dentry);
+	path_put(&path);
+	down_write(&s->s_umount);
+
+	return root;
+}
 
 /*
  * Find a superblock for the given device / mount point.
@@ -784,13 +877,19 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 	if (error)
 		return ERR_PTR(error);
 
+	if (subvol_name) {
+		root = mount_subvol(subvol_name, flags, device_name, data);
+		kfree(subvol_name);
+		return root;
+	}
+
 	error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
 	if (error)
-		goto error_free_subvol_name;
+		return ERR_PTR(error);
 
 	error = btrfs_open_devices(fs_devices, mode, fs_type);
 	if (error)
-		goto error_free_subvol_name;
+		return ERR_PTR(error);
 
 	if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
 		error = -EACCES;
@@ -815,14 +914,15 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 
 	bdev = fs_devices->latest_bdev;
 	s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
-	if (IS_ERR(s))
-		goto error_s;
+	if (IS_ERR(s)) {
+		error = PTR_ERR(s);
+		goto error_close_devices;
+	}
 
 	if (s->s_root) {
 		if ((flags ^ s->s_flags) & MS_RDONLY) {
 			deactivate_locked_super(s);
-			error = -EBUSY;
-			goto error_close_devices;
+			return ERR_PTR(-EBUSY);
 		}
 
 		btrfs_close_devices(fs_devices);
@@ -837,64 +937,25 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 					 flags & MS_SILENT ? 1 : 0);
 		if (error) {
 			deactivate_locked_super(s);
-			goto error_free_subvol_name;
+			return ERR_PTR(error);
 		}
 
 		btrfs_sb(s)->fs_info->bdev_holder = fs_type;
 		s->s_flags |= MS_ACTIVE;
 	}
 
-	/* if they gave us a subvolume name bind mount into that */
-	if (strcmp(subvol_name, ".")) {
-		struct dentry *new_root;
-
-		root = get_default_root(s, subvol_rootid);
-		if (IS_ERR(root)) {
-			error = PTR_ERR(root);
-			deactivate_locked_super(s);
-			goto error_free_subvol_name;
-		}
-
-		mutex_lock(&root->d_inode->i_mutex);
-		new_root = lookup_one_len(subvol_name, root,
-				      strlen(subvol_name));
-		mutex_unlock(&root->d_inode->i_mutex);
-
-		if (IS_ERR(new_root)) {
-			dput(root);
-			deactivate_locked_super(s);
-			error = PTR_ERR(new_root);
-			goto error_free_subvol_name;
-		}
-		if (!new_root->d_inode) {
-			dput(root);
-			dput(new_root);
-			deactivate_locked_super(s);
-			error = -ENXIO;
-			goto error_free_subvol_name;
-		}
-		dput(root);
-		root = new_root;
-	} else {
-		root = get_default_root(s, subvol_objectid);
-		if (IS_ERR(root)) {
-			error = PTR_ERR(root);
-			deactivate_locked_super(s);
-			goto error_free_subvol_name;
-		}
+	root = get_default_root(s, subvol_objectid);
+	if (IS_ERR(root)) {
+		deactivate_locked_super(s);
+		return root;
 	}
 
-	kfree(subvol_name);
 	return root;
 
-error_s:
-	error = PTR_ERR(s);
 error_close_devices:
 	btrfs_close_devices(fs_devices);
 	kfree(fs_info);
 	kfree(tree_root);
-error_free_subvol_name:
-	kfree(subvol_name);
 	return ERR_PTR(error);
 }
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index e24b7964a15..29bef63e23b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -275,7 +275,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
 	 */
 	if (num_items > 0 && root != root->fs_info->chunk_root) {
 		num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
-		ret = btrfs_block_rsv_add(NULL, root,
+		ret = btrfs_block_rsv_add(root,
 					  &root->fs_info->trans_block_rsv,
 					  num_bytes);
 		if (ret)
@@ -418,8 +418,8 @@ static int should_end_transaction(struct btrfs_trans_handle *trans,
 				  struct btrfs_root *root)
 {
 	int ret;
-	ret = btrfs_block_rsv_check(trans, root,
-				    &root->fs_info->global_block_rsv, 0, 5);
+
+	ret = btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
 	return ret ? 1 : 0;
 }
 
@@ -427,17 +427,26 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root)
 {
 	struct btrfs_transaction *cur_trans = trans->transaction;
+	struct btrfs_block_rsv *rsv = trans->block_rsv;
 	int updates;
 
 	smp_mb();
 	if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
 		return 1;
 
+	/*
+	 * We need to do this in case we're deleting csums so the global block
+	 * rsv get's used instead of the csum block rsv.
+	 */
+	trans->block_rsv = NULL;
+
 	updates = trans->delayed_ref_updates;
 	trans->delayed_ref_updates = 0;
 	if (updates)
 		btrfs_run_delayed_refs(trans, root, updates);
 
+	trans->block_rsv = rsv;
+
 	return should_end_transaction(trans, root);
 }
 
@@ -453,6 +462,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 		return 0;
 	}
 
+	btrfs_trans_release_metadata(trans, root);
+	trans->block_rsv = NULL;
 	while (count < 4) {
 		unsigned long cur = trans->delayed_ref_updates;
 		trans->delayed_ref_updates = 0;
@@ -473,8 +484,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 		count++;
 	}
 
-	btrfs_trans_release_metadata(trans, root);
-
 	if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
 	    should_end_transaction(trans, root)) {
 		trans->transaction->blocked = 1;
@@ -562,50 +571,21 @@ int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
 int btrfs_write_marked_extents(struct btrfs_root *root,
 			       struct extent_io_tree *dirty_pages, int mark)
 {
-	int ret;
 	int err = 0;
 	int werr = 0;
-	struct page *page;
-	struct inode *btree_inode = root->fs_info->btree_inode;
+	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
 	u64 start = 0;
 	u64 end;
-	unsigned long index;
-
-	while (1) {
-		ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-					    mark);
-		if (ret)
-			break;
-		while (start <= end) {
-			cond_resched();
-
-			index = start >> PAGE_CACHE_SHIFT;
-			start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-			page = find_get_page(btree_inode->i_mapping, index);
-			if (!page)
-				continue;
-
-			btree_lock_page_hook(page);
-			if (!page->mapping) {
-				unlock_page(page);
-				page_cache_release(page);
-				continue;
-			}
 
-			if (PageWriteback(page)) {
-				if (PageDirty(page))
-					wait_on_page_writeback(page);
-				else {
-					unlock_page(page);
-					page_cache_release(page);
-					continue;
-				}
-			}
-			err = write_one_page(page, 0);
-			if (err)
-				werr = err;
-			page_cache_release(page);
-		}
+	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+				      mark)) {
+		convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark,
+				   GFP_NOFS);
+		err = filemap_fdatawrite_range(mapping, start, end);
+		if (err)
+			werr = err;
+		cond_resched();
+		start = end + 1;
 	}
 	if (err)
 		werr = err;
@@ -621,39 +601,20 @@ int btrfs_write_marked_extents(struct btrfs_root *root,
 int btrfs_wait_marked_extents(struct btrfs_root *root,
 			      struct extent_io_tree *dirty_pages, int mark)
 {
-	int ret;
 	int err = 0;
 	int werr = 0;
-	struct page *page;
-	struct inode *btree_inode = root->fs_info->btree_inode;
+	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
 	u64 start = 0;
 	u64 end;
-	unsigned long index;
-
-	while (1) {
-		ret = find_first_extent_bit(dirty_pages, start, &start, &end,
-					    mark);
-		if (ret)
-			break;
 
-		clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
-		while (start <= end) {
-			index = start >> PAGE_CACHE_SHIFT;
-			start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
-			page = find_get_page(btree_inode->i_mapping, index);
-			if (!page)
-				continue;
-			if (PageDirty(page)) {
-				btree_lock_page_hook(page);
-				wait_on_page_writeback(page);
-				err = write_one_page(page, 0);
-				if (err)
-					werr = err;
-			}
-			wait_on_page_writeback(page);
-			page_cache_release(page);
-			cond_resched();
-		}
+	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
+				      EXTENT_NEED_WAIT)) {
+		clear_extent_bits(dirty_pages, start, end, EXTENT_NEED_WAIT, GFP_NOFS);
+		err = filemap_fdatawait_range(mapping, start, end);
+		if (err)
+			werr = err;
+		cond_resched();
+		start = end + 1;
 	}
 	if (err)
 		werr = err;
@@ -911,10 +872,9 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	}
 
 	btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
-	btrfs_orphan_pre_snapshot(trans, pending, &to_reserve);
 
 	if (to_reserve > 0) {
-		ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv,
+		ret = btrfs_block_rsv_add(root, &pending->block_rsv,
 					  to_reserve);
 		if (ret) {
 			pending->error = ret;
@@ -1002,7 +962,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	BUG_ON(IS_ERR(pending->snap));
 
 	btrfs_reloc_post_snapshot(trans, pending);
-	btrfs_orphan_post_snapshot(trans, pending);
 fail:
 	kfree(new_root_item);
 	trans->block_rsv = rsv;
@@ -1043,7 +1002,7 @@ static void update_super_roots(struct btrfs_root *root)
 	super->root = root_item->bytenr;
 	super->generation = root_item->generation;
 	super->root_level = root_item->level;
-	if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE))
+	if (btrfs_test_opt(root, SPACE_CACHE))
 		super->cache_generation = root_item->generation;
 }
 
@@ -1168,14 +1127,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
 	btrfs_run_ordered_operations(root, 0);
 
+	btrfs_trans_release_metadata(trans, root);
+	trans->block_rsv = NULL;
+
 	/* make a pass through all the delayed refs we have so far
 	 * any runnings procs may add more while we are here
 	 */
 	ret = btrfs_run_delayed_refs(trans, root, 0);
 	BUG_ON(ret);
 
-	btrfs_trans_release_metadata(trans, root);
-
 	cur_trans = trans->transaction;
 	/*
 	 * set the flushing flag so procs in this transaction have to
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f2a4cc79da6..e138af710de 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1013,8 +1013,13 @@ static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
 	}
 	BUG_ON(ret);
 
-	if (device->bytes_used > 0)
-		device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
+	if (device->bytes_used > 0) {
+		u64 len = btrfs_dev_extent_length(leaf, extent);
+		device->bytes_used -= len;
+		spin_lock(&root->fs_info->free_chunk_lock);
+		root->fs_info->free_chunk_space += len;
+		spin_unlock(&root->fs_info->free_chunk_lock);
+	}
 	ret = btrfs_del_item(trans, root, path);
 
 out:
@@ -1356,6 +1361,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (ret)
 		goto error_undo;
 
+	spin_lock(&root->fs_info->free_chunk_lock);
+	root->fs_info->free_chunk_space = device->total_bytes -
+		device->bytes_used;
+	spin_unlock(&root->fs_info->free_chunk_lock);
+
 	device->in_fs_metadata = 0;
 	btrfs_scrub_cancel_dev(root, device);
 
@@ -1691,6 +1701,10 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 		root->fs_info->fs_devices->num_can_discard++;
 	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
 
+	spin_lock(&root->fs_info->free_chunk_lock);
+	root->fs_info->free_chunk_space += device->total_bytes;
+	spin_unlock(&root->fs_info->free_chunk_lock);
+
 	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
 		root->fs_info->fs_devices->rotating = 1;
 
@@ -2192,8 +2206,12 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	lock_chunks(root);
 
 	device->total_bytes = new_size;
-	if (device->writeable)
+	if (device->writeable) {
 		device->fs_devices->total_rw_bytes -= diff;
+		spin_lock(&root->fs_info->free_chunk_lock);
+		root->fs_info->free_chunk_space -= diff;
+		spin_unlock(&root->fs_info->free_chunk_lock);
+	}
 	unlock_chunks(root);
 
 again:
@@ -2257,6 +2275,9 @@ again:
 		device->total_bytes = old_size;
 		if (device->writeable)
 			device->fs_devices->total_rw_bytes += diff;
+		spin_lock(&root->fs_info->free_chunk_lock);
+		root->fs_info->free_chunk_space += diff;
+		spin_unlock(&root->fs_info->free_chunk_lock);
 		unlock_chunks(root);
 		goto done;
 	}
@@ -2615,6 +2636,11 @@ static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
 		index++;
 	}
 
+	spin_lock(&extent_root->fs_info->free_chunk_lock);
+	extent_root->fs_info->free_chunk_space -= (stripe_size *
+						   map->num_stripes);
+	spin_unlock(&extent_root->fs_info->free_chunk_lock);
+
 	index = 0;
 	stripe = &chunk->stripe;
 	while (index < map->num_stripes) {
@@ -3616,8 +3642,13 @@ static int read_one_dev(struct btrfs_root *root,
 	fill_device_from_item(leaf, dev_item, device);
 	device->dev_root = root->fs_info->dev_root;
 	device->in_fs_metadata = 1;
-	if (device->writeable)
+	if (device->writeable) {
 		device->fs_devices->total_rw_bytes += device->total_bytes;
+		spin_lock(&root->fs_info->free_chunk_lock);
+		root->fs_info->free_chunk_space += device->total_bytes -
+			device->bytes_used;
+		spin_unlock(&root->fs_info->free_chunk_lock);
+	}
 	ret = 0;
 	return ret;
 }
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 69565e5fc6a..a76e41c04b7 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -127,6 +127,17 @@ static int do_setxattr(struct btrfs_trans_handle *trans,
 again:
 	ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
 				      name, name_len, value, size);
+	/*
+	 * If we're setting an xattr to a new value but the new value is say
+	 * exactly BTRFS_MAX_XATTR_SIZE, we could end up with EOVERFLOW getting
+	 * back from split_leaf.  This is because it thinks we'll be extending
+	 * the existing item size, but we're asking for enough space to add the
+	 * item itself.  So if we get EOVERFLOW just set ret to EEXIST and let
+	 * the rest of the function figure it out.
+	 */
+	if (ret == -EOVERFLOW)
+		ret = -EEXIST;
+
 	if (ret == -EEXIST) {
 		if (flags & XATTR_CREATE)
 			goto out;