Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "I've been running these through a longer set of load tests because my
  commits change the free space cache writeout.  It fixes commit stalls
  on large filesystems (~20T space used and up) that we have been
  triggering here.  We were seeing new writers blocked for 10 seconds or
  more during commits, which is far from good.

  Josef and I fixed up ENOSPC aborts when deleting huge files (3T or
  more), that are triggered because our metadata reservations were not
  properly accounting for crcs and were not replenishing during the
  truncate.

  Also in this series, a number of qgroup fixes from Fujitsu and Dave
  Sterba collected most of the pending cleanups from the list"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (93 commits)
  btrfs: quota: Update quota tree after qgroup relationship change.
  btrfs: quota: Automatically update related qgroups or mark INCONSISTENT flags when assigning/deleting a qgroup relations.
  btrfs: qgroup: clear STATUS_FLAG_ON in disabling quota.
  btrfs: Update btrfs qgroup status item when rescan is done.
  btrfs: qgroup: Fix dead judgement on qgroup_rescan_leaf() return value.
  btrfs: Don't allow subvolid >= (1 << BTRFS_QGROUP_LEVEL_SHIFT) to be created
  btrfs: Check qgroup level in kernel qgroup assign.
  btrfs: qgroup: allow to remove qgroup which has parent but no child.
  btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
  btrfs: qgroup: do a reservation in a higher level.
  Btrfs: qgroup, Account data space in more proper timings.
  Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
  Btrfs: qgroup: free reserved in exceeding quota.
  Btrfs: qgroup: cleanup, remove an unsued parameter in btrfs_create_qgroup().
  btrfs: qgroup: fix limit args override whole limit struct
  btrfs: qgroup: update limit info in function btrfs_run_qgroups().
  btrfs: qgroup: consolidate the parameter of fucntion update_qgroup_limit_item().
  btrfs: qgroup: update qgroup in memory at the same time when we update it in btree.
  btrfs: qgroup: inherit limit info from srcgroup in creating snapshot.
  btrfs: Support busy loop of write and delete
  ...

1 files changed, 208 insertions, 93 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index a71978578fa7..253cb74b0e27 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -85,7 +85,8 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 	}
 
 	mapping_set_gfp_mask(inode->i_mapping,
-			mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
+			mapping_gfp_mask(inode->i_mapping) &
+			~(GFP_NOFS & ~__GFP_HIGHMEM));
 
 	return inode;
 }
@@ -170,13 +171,13 @@ static int __create_free_space_inode(struct btrfs_root *root,
 	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
 	key.offset = offset;
 	key.type = 0;
-
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
 				      sizeof(struct btrfs_free_space_header));
 	if (ret < 0) {
 		btrfs_release_path(path);
 		return ret;
 	}
+
 	leaf = path->nodes[0];
 	header = btrfs_item_ptr(leaf, path->slots[0],
 				struct btrfs_free_space_header);
@@ -225,9 +226,37 @@ int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
 
 int btrfs_truncate_free_space_cache(struct btrfs_root *root,
 				    struct btrfs_trans_handle *trans,
+				    struct btrfs_block_group_cache *block_group,
 				    struct inode *inode)
 {
 	int ret = 0;
+	struct btrfs_path *path = btrfs_alloc_path();
+
+	if (!path) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	if (block_group) {
+		mutex_lock(&trans->transaction->cache_write_mutex);
+		if (!list_empty(&block_group->io_list)) {
+			list_del_init(&block_group->io_list);
+
+			btrfs_wait_cache_io(root, trans, block_group,
+					    &block_group->io_ctl, path,
+					    block_group->key.objectid);
+			btrfs_put_block_group(block_group);
+		}
+
+		/*
+		 * now that we've truncated the cache away, its no longer
+		 * setup or written
+		 */
+		spin_lock(&block_group->lock);
+		block_group->disk_cache_state = BTRFS_DC_CLEAR;
+		spin_unlock(&block_group->lock);
+	}
+	btrfs_free_path(path);
 
 	btrfs_i_size_write(inode, 0);
 	truncate_pagecache(inode, 0);
@@ -235,15 +264,23 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root,
 	/*
 	 * We don't need an orphan item because truncating the free space cache
 	 * will never be split across transactions.
+	 * We don't need to check for -EAGAIN because we're a free space
+	 * cache inode
 	 */
 	ret = btrfs_truncate_inode_items(trans, root, inode,
 					 0, BTRFS_EXTENT_DATA_KEY);
 	if (ret) {
+		mutex_unlock(&trans->transaction->cache_write_mutex);
 		btrfs_abort_transaction(trans, root, ret);
 		return ret;
 	}
 
 	ret = btrfs_update_inode(trans, root, inode);
+
+	if (block_group)
+		mutex_unlock(&trans->transaction->cache_write_mutex);
+
+fail:
 	if (ret)
 		btrfs_abort_transaction(trans, root, ret);
 
@@ -269,18 +306,7 @@ 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,
+static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
 		       struct btrfs_root *root, int write)
 {
 	int num_pages;
@@ -296,45 +322,46 @@ static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
 	    (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
 		return -ENOSPC;
 
-	memset(io_ctl, 0, sizeof(struct io_ctl));
+	memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
 
-	io_ctl->pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
+	io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
 	if (!io_ctl->pages)
 		return -ENOMEM;
 
 	io_ctl->num_pages = num_pages;
 	io_ctl->root = root;
 	io_ctl->check_crcs = check_crcs;
+	io_ctl->inode = inode;
 
 	return 0;
 }
 
-static void io_ctl_free(struct io_ctl *io_ctl)
+static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
 {
 	kfree(io_ctl->pages);
+	io_ctl->pages = NULL;
 }
 
-static void io_ctl_unmap_page(struct io_ctl *io_ctl)
+static void io_ctl_unmap_page(struct btrfs_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)
+static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
 {
 	ASSERT(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->cur = page_address(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)
+static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
 {
 	int i;
 
@@ -349,7 +376,7 @@ static void io_ctl_drop_pages(struct io_ctl *io_ctl)
 	}
 }
 
-static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
+static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
 				int uptodate)
 {
 	struct page *page;
@@ -383,7 +410,7 @@ static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
 	return 0;
 }
 
-static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
+static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
 {
 	__le64 *val;
 
@@ -406,7 +433,7 @@ static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
 	io_ctl->cur += sizeof(u64);
 }
 
-static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
+static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
 {
 	__le64 *gen;
 
@@ -435,7 +462,7 @@ static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
 	return 0;
 }
 
-static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
+static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
 {
 	u32 *tmp;
 	u32 crc = ~(u32)0;
@@ -453,13 +480,12 @@ static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
 			      PAGE_CACHE_SIZE - offset);
 	btrfs_csum_final(crc, (char *)&crc);
 	io_ctl_unmap_page(io_ctl);
-	tmp = kmap(io_ctl->pages[0]);
+	tmp = page_address(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)
+static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
 {
 	u32 *tmp, val;
 	u32 crc = ~(u32)0;
@@ -473,10 +499,9 @@ static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
 	if (index == 0)
 		offset = sizeof(u32) * io_ctl->num_pages;
 
-	tmp = kmap(io_ctl->pages[0]);
+	tmp = page_address(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->orig + offset, crc,
@@ -492,7 +517,7 @@ static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
 	return 0;
 }
 
-static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
+static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
 			    void *bitmap)
 {
 	struct btrfs_free_space_entry *entry;
@@ -522,7 +547,7 @@ static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
 	return 0;
 }
 
-static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
+static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
 {
 	if (!io_ctl->cur)
 		return -ENOSPC;
@@ -545,7 +570,7 @@ static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
 	return 0;
 }
 
-static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
+static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
 {
 	/*
 	 * If we're not on the boundary we know we've modified the page and we
@@ -562,7 +587,7 @@ static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
 	}
 }
 
-static int io_ctl_read_entry(struct io_ctl *io_ctl,
+static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
 			    struct btrfs_free_space *entry, u8 *type)
 {
 	struct btrfs_free_space_entry *e;
@@ -589,7 +614,7 @@ static int io_ctl_read_entry(struct io_ctl *io_ctl,
 	return 0;
 }
 
-static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
+static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
 			      struct btrfs_free_space *entry)
 {
 	int ret;
@@ -648,7 +673,7 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 {
 	struct btrfs_free_space_header *header;
 	struct extent_buffer *leaf;
-	struct io_ctl io_ctl;
+	struct btrfs_io_ctl io_ctl;
 	struct btrfs_key key;
 	struct btrfs_free_space *e, *n;
 	LIST_HEAD(bitmaps);
@@ -877,7 +902,7 @@ out:
 }
 
 static noinline_for_stack
-int write_cache_extent_entries(struct io_ctl *io_ctl,
+int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
 			      struct btrfs_free_space_ctl *ctl,
 			      struct btrfs_block_group_cache *block_group,
 			      int *entries, int *bitmaps,
@@ -885,6 +910,7 @@ int write_cache_extent_entries(struct io_ctl *io_ctl,
 {
 	int ret;
 	struct btrfs_free_cluster *cluster = NULL;
+	struct btrfs_free_cluster *cluster_locked = NULL;
 	struct rb_node *node = rb_first(&ctl->free_space_offset);
 	struct btrfs_trim_range *trim_entry;
 
@@ -896,6 +922,8 @@ int write_cache_extent_entries(struct io_ctl *io_ctl,
 	}
 
 	if (!node && cluster) {
+		cluster_locked = cluster;
+		spin_lock(&cluster_locked->lock);
 		node = rb_first(&cluster->root);
 		cluster = NULL;
 	}
@@ -919,9 +947,15 @@ int write_cache_extent_entries(struct io_ctl *io_ctl,
 		node = rb_next(node);
 		if (!node && cluster) {
 			node = rb_first(&cluster->root);
+			cluster_locked = cluster;
+			spin_lock(&cluster_locked->lock);
 			cluster = NULL;
 		}
 	}
+	if (cluster_locked) {
+		spin_unlock(&cluster_locked->lock);
+		cluster_locked = NULL;
+	}
 
 	/*
 	 * Make sure we don't miss any range that was removed from our rbtree
@@ -939,6 +973,8 @@ int write_cache_extent_entries(struct io_ctl *io_ctl,
 
 	return 0;
 fail:
+	if (cluster_locked)
+		spin_unlock(&cluster_locked->lock);
 	return -ENOSPC;
 }
 
@@ -1000,7 +1036,7 @@ fail:
 static noinline_for_stack int
 write_pinned_extent_entries(struct btrfs_root *root,
 			    struct btrfs_block_group_cache *block_group,
-			    struct io_ctl *io_ctl,
+			    struct btrfs_io_ctl *io_ctl,
 			    int *entries)
 {
 	u64 start, extent_start, extent_end, len;
@@ -1050,7 +1086,7 @@ write_pinned_extent_entries(struct btrfs_root *root,
 }
 
 static noinline_for_stack int
-write_bitmap_entries(struct io_ctl *io_ctl, struct list_head *bitmap_list)
+write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
 {
 	struct list_head *pos, *n;
 	int ret;
@@ -1084,7 +1120,7 @@ static int flush_dirty_cache(struct inode *inode)
 
 static void noinline_for_stack
 cleanup_write_cache_enospc(struct inode *inode,
-			   struct io_ctl *io_ctl,
+			   struct btrfs_io_ctl *io_ctl,
 			   struct extent_state **cached_state,
 			   struct list_head *bitmap_list)
 {
@@ -1101,6 +1137,70 @@ cleanup_write_cache_enospc(struct inode *inode,
 			     GFP_NOFS);
 }
 
+int btrfs_wait_cache_io(struct btrfs_root *root,
+			struct btrfs_trans_handle *trans,
+			struct btrfs_block_group_cache *block_group,
+			struct btrfs_io_ctl *io_ctl,
+			struct btrfs_path *path, u64 offset)
+{
+	int ret;
+	struct inode *inode = io_ctl->inode;
+
+	if (!inode)
+		return 0;
+
+	root = root->fs_info->tree_root;
+
+	/* Flush the dirty pages in the cache file. */
+	ret = flush_dirty_cache(inode);
+	if (ret)
+		goto out;
+
+	/* Update the cache item to tell everyone this cache file is valid. */
+	ret = update_cache_item(trans, root, inode, path, offset,
+				io_ctl->entries, io_ctl->bitmaps);
+out:
+	io_ctl_free(io_ctl);
+	if (ret) {
+		invalidate_inode_pages2(inode->i_mapping);
+		BTRFS_I(inode)->generation = 0;
+		if (block_group) {
+#ifdef DEBUG
+			btrfs_err(root->fs_info,
+				"failed to write free space cache for block group %llu",
+				block_group->key.objectid);
+#endif
+		}
+	}
+	btrfs_update_inode(trans, root, inode);
+
+	if (block_group) {
+		/* the dirty list is protected by the dirty_bgs_lock */
+		spin_lock(&trans->transaction->dirty_bgs_lock);
+
+		/* the disk_cache_state is protected by the block group lock */
+		spin_lock(&block_group->lock);
+
+		/*
+		 * only mark this as written if we didn't get put back on
+		 * the dirty list while waiting for IO.   Otherwise our
+		 * cache state won't be right, and we won't get written again
+		 */
+		if (!ret && list_empty(&block_group->dirty_list))
+			block_group->disk_cache_state = BTRFS_DC_WRITTEN;
+		else if (ret)
+			block_group->disk_cache_state = BTRFS_DC_ERROR;
+
+		spin_unlock(&block_group->lock);
+		spin_unlock(&trans->transaction->dirty_bgs_lock);
+		io_ctl->inode = NULL;
+		iput(inode);
+	}
+
+	return ret;
+
+}
+
 /**
  * __btrfs_write_out_cache - write out cached info to an inode
  * @root - the root the inode belongs to
@@ -1117,20 +1217,22 @@ cleanup_write_cache_enospc(struct inode *inode,
 static 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,
+				   struct btrfs_io_ctl *io_ctl,
 				   struct btrfs_trans_handle *trans,
 				   struct btrfs_path *path, u64 offset)
 {
 	struct extent_state *cached_state = NULL;
-	struct io_ctl io_ctl;
 	LIST_HEAD(bitmap_list);
 	int entries = 0;
 	int bitmaps = 0;
 	int ret;
+	int must_iput = 0;
 
 	if (!i_size_read(inode))
 		return -1;
 
-	ret = io_ctl_init(&io_ctl, inode, root, 1);
+	WARN_ON(io_ctl->pages);
+	ret = io_ctl_init(io_ctl, inode, root, 1);
 	if (ret)
 		return -1;
 
@@ -1143,24 +1245,27 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 			up_write(&block_group->data_rwsem);
 			BTRFS_I(inode)->generation = 0;
 			ret = 0;
+			must_iput = 1;
 			goto out;
 		}
 		spin_unlock(&block_group->lock);
 	}
 
 	/* Lock all pages first so we can lock the extent safely. */
-	io_ctl_prepare_pages(&io_ctl, inode, 0);
+	io_ctl_prepare_pages(io_ctl, inode, 0);
 
 	lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
 			 0, &cached_state);
 
-	io_ctl_set_generation(&io_ctl, trans->transid);
+	io_ctl_set_generation(io_ctl, trans->transid);
 
 	mutex_lock(&ctl->cache_writeout_mutex);
 	/* Write out the extent entries in the free space cache */
-	ret = write_cache_extent_entries(&io_ctl, ctl,
+	spin_lock(&ctl->tree_lock);
+	ret = write_cache_extent_entries(io_ctl, ctl,
 					 block_group, &entries, &bitmaps,
 					 &bitmap_list);
+	spin_unlock(&ctl->tree_lock);
 	if (ret) {
 		mutex_unlock(&ctl->cache_writeout_mutex);
 		goto out_nospc;
@@ -1170,8 +1275,11 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	 * Some spaces that are freed in the current transaction are pinned,
 	 * they will be added into free space cache after the transaction is
 	 * committed, we shouldn't lose them.
+	 *
+	 * If this changes while we are working we'll get added back to
+	 * the dirty list and redo it.  No locking needed
 	 */
-	ret = write_pinned_extent_entries(root, block_group, &io_ctl, &entries);
+	ret = write_pinned_extent_entries(root, block_group, io_ctl, &entries);
 	if (ret) {
 		mutex_unlock(&ctl->cache_writeout_mutex);
 		goto out_nospc;
@@ -1182,16 +1290,18 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	 * locked while doing it because a concurrent trim can be manipulating
 	 * or freeing the bitmap.
 	 */
-	ret = write_bitmap_entries(&io_ctl, &bitmap_list);
+	spin_lock(&ctl->tree_lock);
+	ret = write_bitmap_entries(io_ctl, &bitmap_list);
+	spin_unlock(&ctl->tree_lock);
 	mutex_unlock(&ctl->cache_writeout_mutex);
 	if (ret)
 		goto out_nospc;
 
 	/* Zero out the rest of the pages just to make sure */
-	io_ctl_zero_remaining_pages(&io_ctl);
+	io_ctl_zero_remaining_pages(io_ctl);
 
 	/* Everything is written out, now we dirty the pages in the file. */
-	ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
+	ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages,
 				0, i_size_read(inode), &cached_state);
 	if (ret)
 		goto out_nospc;
@@ -1202,30 +1312,39 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	 * Release the pages and unlock the extent, we will flush
 	 * them out later
 	 */
-	io_ctl_drop_pages(&io_ctl);
+	io_ctl_drop_pages(io_ctl);
 
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
 			     i_size_read(inode) - 1, &cached_state, GFP_NOFS);
 
-	/* Flush the dirty pages in the cache file. */
-	ret = flush_dirty_cache(inode);
+	/*
+	 * at this point the pages are under IO and we're happy,
+	 * The caller is responsible for waiting on them and updating the
+	 * the cache and the inode
+	 */
+	io_ctl->entries = entries;
+	io_ctl->bitmaps = bitmaps;
+
+	ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
 	if (ret)
 		goto out;
 
-	/* Update the cache item to tell everyone this cache file is valid. */
-	ret = update_cache_item(trans, root, inode, path, offset,
-				entries, bitmaps);
+	return 0;
+
 out:
-	io_ctl_free(&io_ctl);
+	io_ctl->inode = NULL;
+	io_ctl_free(io_ctl);
 	if (ret) {
 		invalidate_inode_pages2(inode->i_mapping);
 		BTRFS_I(inode)->generation = 0;
 	}
 	btrfs_update_inode(trans, root, inode);
+	if (must_iput)
+		iput(inode);
 	return ret;
 
 out_nospc:
-	cleanup_write_cache_enospc(inode, &io_ctl, &cached_state, &bitmap_list);
+	cleanup_write_cache_enospc(inode, io_ctl, &cached_state, &bitmap_list);
 
 	if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
 		up_write(&block_group->data_rwsem);
@@ -1241,7 +1360,6 @@ int btrfs_write_out_cache(struct btrfs_root *root,
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct inode *inode;
 	int ret = 0;
-	enum btrfs_disk_cache_state dcs = BTRFS_DC_WRITTEN;
 
 	root = root->fs_info->tree_root;
 
@@ -1250,34 +1368,34 @@ int btrfs_write_out_cache(struct btrfs_root *root,
 		spin_unlock(&block_group->lock);
 		return 0;
 	}
-
-	if (block_group->delalloc_bytes) {
-		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		return 0;
-	}
 	spin_unlock(&block_group->lock);
 
 	inode = lookup_free_space_inode(root, block_group, path);
 	if (IS_ERR(inode))
 		return 0;
 
-	ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
+	ret = __btrfs_write_out_cache(root, inode, ctl, block_group,
+				      &block_group->io_ctl, trans,
 				      path, block_group->key.objectid);
 	if (ret) {
-		dcs = BTRFS_DC_ERROR;
-		ret = 0;
 #ifdef DEBUG
 		btrfs_err(root->fs_info,
 			"failed to write free space cache for block group %llu",
 			block_group->key.objectid);
 #endif
+		spin_lock(&block_group->lock);
+		block_group->disk_cache_state = BTRFS_DC_ERROR;
+		spin_unlock(&block_group->lock);
+
+		block_group->io_ctl.inode = NULL;
+		iput(inode);
 	}
 
-	spin_lock(&block_group->lock);
-	block_group->disk_cache_state = dcs;
-	spin_unlock(&block_group->lock);
-	iput(inode);
+	/*
+	 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
+	 * to wait for IO and put the inode
+	 */
+
 	return ret;
 }
 
@@ -1298,11 +1416,11 @@ static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
 				   u64 offset)
 {
 	u64 bitmap_start;
-	u64 bytes_per_bitmap;
+	u32 bytes_per_bitmap;
 
 	bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
 	bitmap_start = offset - ctl->start;
-	bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
+	bitmap_start = div_u64(bitmap_start, bytes_per_bitmap);
 	bitmap_start *= bytes_per_bitmap;
 	bitmap_start += ctl->start;
 
@@ -1521,10 +1639,10 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
 	u64 bitmap_bytes;
 	u64 extent_bytes;
 	u64 size = block_group->key.offset;
-	u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
-	int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
+	u32 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
+	u32 max_bitmaps = div_u64(size + bytes_per_bg - 1, bytes_per_bg);
 
-	max_bitmaps = max(max_bitmaps, 1);
+	max_bitmaps = max_t(u32, max_bitmaps, 1);
 
 	ASSERT(ctl->total_bitmaps <= max_bitmaps);
 
@@ -1537,7 +1655,7 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
 		max_bytes = MAX_CACHE_BYTES_PER_GIG;
 	else
 		max_bytes = MAX_CACHE_BYTES_PER_GIG *
-			div64_u64(size, 1024 * 1024 * 1024);
+			div_u64(size, 1024 * 1024 * 1024);
 
 	/*
 	 * we want to account for 1 more bitmap than what we have so we can make
@@ -1552,14 +1670,14 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
 	}
 
 	/*
-	 * we want the extent entry threshold to always be at most 1/2 the maxw
+	 * we want the extent entry threshold to always be at most 1/2 the max
 	 * bytes we can have, or whatever is less than that.
 	 */
 	extent_bytes = max_bytes - bitmap_bytes;
-	extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
+	extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
 
 	ctl->extents_thresh =
-		div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
+		div_u64(extent_bytes, sizeof(struct btrfs_free_space));
 }
 
 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
@@ -1673,7 +1791,7 @@ find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
 		 */
 		if (*bytes >= align) {
 			tmp = entry->offset - ctl->start + align - 1;
-			do_div(tmp, align);
+			tmp = div64_u64(tmp, align);
 			tmp = tmp * align + ctl->start;
 			align_off = tmp - entry->offset;
 		} else {
@@ -2402,11 +2520,8 @@ static void __btrfs_remove_free_space_cache_locked(
 		} else {
 			free_bitmap(ctl, info);
 		}
-		if (need_resched()) {
-			spin_unlock(&ctl->tree_lock);
-			cond_resched();
-			spin_lock(&ctl->tree_lock);
-		}
+
+		cond_resched_lock(&ctl->tree_lock);
 	}
 }
 
@@ -2431,11 +2546,8 @@ void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
 
 		WARN_ON(cluster->block_group != block_group);
 		__btrfs_return_cluster_to_free_space(block_group, cluster);
-		if (need_resched()) {
-			spin_unlock(&ctl->tree_lock);
-			cond_resched();
-			spin_lock(&ctl->tree_lock);
-		}
+
+		cond_resched_lock(&ctl->tree_lock);
 	}
 	__btrfs_remove_free_space_cache_locked(ctl);
 	spin_unlock(&ctl->tree_lock);
@@ -3346,11 +3458,14 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
 {
 	struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
 	int ret;
+	struct btrfs_io_ctl io_ctl;
 
 	if (!btrfs_test_opt(root, INODE_MAP_CACHE))
 		return 0;
 
-	ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
+	ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl,
+				      trans, path, 0) ||
+		btrfs_wait_cache_io(root, trans, NULL, &io_ctl, path, 0);
 	if (ret) {
 		btrfs_delalloc_release_metadata(inode, inode->i_size);
 #ifdef DEBUG