Merge drm/drm-next into drm-misc-next

Backmerging required to pull topic/phy-compliance.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

1 files changed, 478 insertions, 436 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c6c9a6a8e6c8..a6cb5cbbdb9f 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -7,7 +7,6 @@
 #include <linux/blkdev.h>
 #include <linux/radix-tree.h>
 #include <linux/writeback.h>
-#include <linux/buffer_head.h>
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
 #include <linux/slab.h>
@@ -42,6 +41,7 @@
 #include "ref-verify.h"
 #include "block-group.h"
 #include "discard.h"
+#include "space-info.h"
 
 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
 				 BTRFS_HEADER_FLAG_RELOC |\
@@ -98,6 +98,12 @@ void __cold btrfs_end_io_wq_exit(void)
 	kmem_cache_destroy(btrfs_end_io_wq_cache);
 }
 
+static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
+{
+	if (fs_info->csum_shash)
+		crypto_free_shash(fs_info->csum_shash);
+}
+
 /*
  * async submit bios are used to offload expensive checksumming
  * onto the worker threads.  They checksum file and metadata bios
@@ -247,47 +253,27 @@ out:
 
 /*
  * Compute the csum of a btree block and store the result to provided buffer.
- *
- * Returns error if the extent buffer cannot be mapped.
  */
-static int csum_tree_block(struct extent_buffer *buf, u8 *result)
+static void csum_tree_block(struct extent_buffer *buf, u8 *result)
 {
 	struct btrfs_fs_info *fs_info = buf->fs_info;
+	const int num_pages = fs_info->nodesize >> PAGE_SHIFT;
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
-	unsigned long len;
-	unsigned long cur_len;
-	unsigned long offset = BTRFS_CSUM_SIZE;
 	char *kaddr;
-	unsigned long map_start;
-	unsigned long map_len;
-	int err;
+	int i;
 
 	shash->tfm = fs_info->csum_shash;
 	crypto_shash_init(shash);
+	kaddr = page_address(buf->pages[0]);
+	crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
+			    PAGE_SIZE - BTRFS_CSUM_SIZE);
 
-	len = buf->len - offset;
-
-	while (len > 0) {
-		/*
-		 * Note: we don't need to check for the err == 1 case here, as
-		 * with the given combination of 'start = BTRFS_CSUM_SIZE (32)'
-		 * and 'min_len = 32' and the currently implemented mapping
-		 * algorithm we cannot cross a page boundary.
-		 */
-		err = map_private_extent_buffer(buf, offset, 32,
-					&kaddr, &map_start, &map_len);
-		if (WARN_ON(err))
-			return err;
-		cur_len = min(len, map_len - (offset - map_start));
-		crypto_shash_update(shash, kaddr + offset - map_start, cur_len);
-		len -= cur_len;
-		offset += cur_len;
+	for (i = 1; i < num_pages; i++) {
+		kaddr = page_address(buf->pages[i]);
+		crypto_shash_update(shash, kaddr, PAGE_SIZE);
 	}
 	memset(result, 0, BTRFS_CSUM_SIZE);
-
 	crypto_shash_final(shash, result);
-
-	return 0;
 }
 
 /*
@@ -535,10 +521,10 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
 		return -EUCLEAN;
 
 	ASSERT(memcmp_extent_buffer(eb, fs_info->fs_devices->metadata_uuid,
-			btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
+				    offsetof(struct btrfs_header, fsid),
+				    BTRFS_FSID_SIZE) == 0);
 
-	if (csum_tree_block(eb, result))
-		return -EINVAL;
+	csum_tree_block(eb, result);
 
 	if (btrfs_header_level(eb))
 		ret = btrfs_check_node(eb);
@@ -565,7 +551,8 @@ static int check_tree_block_fsid(struct extent_buffer *eb)
 	u8 fsid[BTRFS_FSID_SIZE];
 	int ret = 1;
 
-	read_extent_buffer(eb, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
+	read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
+			   BTRFS_FSID_SIZE);
 	while (fs_devices) {
 		u8 *metadata_uuid;
 
@@ -596,9 +583,8 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 	u64 found_start;
 	int found_level;
 	struct extent_buffer *eb;
-	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
+	struct btrfs_fs_info *fs_info;
+	u16 csum_size;
 	int ret = 0;
 	u8 result[BTRFS_CSUM_SIZE];
 	int reads_done;
@@ -607,6 +593,8 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 		goto out;
 
 	eb = (struct extent_buffer *)page->private;
+	fs_info = eb->fs_info;
+	csum_size = btrfs_super_csum_size(fs_info->super_copy);
 
 	/* the pending IO might have been the only thing that kept this buffer
 	 * in memory.  Make sure we have a ref for all this other checks
@@ -647,9 +635,7 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 	btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 				       eb, found_level);
 
-	ret = csum_tree_block(eb, result);
-	if (ret)
-		goto err;
+	csum_tree_block(eb, result);
 
 	if (memcmp_extent_buffer(eb, result, 0, csum_size)) {
 		u32 val;
@@ -972,9 +958,7 @@ static int btree_writepages(struct address_space *mapping,
 
 static int btree_readpage(struct file *file, struct page *page)
 {
-	struct extent_io_tree *tree;
-	tree = &BTRFS_I(page->mapping->host)->io_tree;
-	return extent_read_full_page(tree, page, btree_get_extent, 0);
+	return extent_read_full_page(page, btree_get_extent, 0);
 }
 
 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
@@ -1100,36 +1084,11 @@ void btrfs_clean_tree_block(struct extent_buffer *buf)
 	}
 }
 
-static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
-{
-	struct btrfs_subvolume_writers *writers;
-	int ret;
-
-	writers = kmalloc(sizeof(*writers), GFP_NOFS);
-	if (!writers)
-		return ERR_PTR(-ENOMEM);
-
-	ret = percpu_counter_init(&writers->counter, 0, GFP_NOFS);
-	if (ret < 0) {
-		kfree(writers);
-		return ERR_PTR(ret);
-	}
-
-	init_waitqueue_head(&writers->wait);
-	return writers;
-}
-
-static void
-btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
-{
-	percpu_counter_destroy(&writers->counter);
-	kfree(writers);
-}
-
 static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 			 u64 objectid)
 {
 	bool dummy = test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
+	root->fs_info = fs_info;
 	root->node = NULL;
 	root->commit_root = NULL;
 	root->state = 0;
@@ -1173,7 +1132,6 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 	atomic_set(&root->log_writers, 0);
 	atomic_set(&root->log_batch, 0);
 	refcount_set(&root->refs, 1);
-	atomic_set(&root->will_be_snapshotted, 0);
 	atomic_set(&root->snapshot_force_cow, 0);
 	atomic_set(&root->nr_swapfiles, 0);
 	root->log_transid = 0;
@@ -1195,14 +1153,20 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
 
 	spin_lock_init(&root->root_item_lock);
 	btrfs_qgroup_init_swapped_blocks(&root->swapped_blocks);
+#ifdef CONFIG_BTRFS_DEBUG
+	INIT_LIST_HEAD(&root->leak_list);
+	spin_lock(&fs_info->fs_roots_radix_lock);
+	list_add_tail(&root->leak_list, &fs_info->allocated_roots);
+	spin_unlock(&fs_info->fs_roots_radix_lock);
+#endif
 }
 
 static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info,
-		gfp_t flags)
+					   u64 objectid, gfp_t flags)
 {
 	struct btrfs_root *root = kzalloc(sizeof(*root), flags);
 	if (root)
-		root->fs_info = fs_info;
+		__setup_root(root, fs_info, objectid);
 	return root;
 }
 
@@ -1215,12 +1179,11 @@ struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info)
 	if (!fs_info)
 		return ERR_PTR(-EINVAL);
 
-	root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+	root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
 	/* We don't use the stripesize in selftest, set it as sectorsize */
-	__setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
 	root->alloc_bytenr = 0;
 
 	return root;
@@ -1237,19 +1200,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	unsigned int nofs_flag;
 	int ret = 0;
-	uuid_le uuid = NULL_UUID_LE;
 
 	/*
 	 * We're holding a transaction handle, so use a NOFS memory allocation
 	 * context to avoid deadlock if reclaim happens.
 	 */
 	nofs_flag = memalloc_nofs_save();
-	root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+	root = btrfs_alloc_root(fs_info, objectid, GFP_KERNEL);
 	memalloc_nofs_restore(nofs_flag);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
-	__setup_root(root, fs_info, objectid);
 	root->root_key.objectid = objectid;
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 	root->root_key.offset = 0;
@@ -1277,8 +1238,9 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	btrfs_set_root_last_snapshot(&root->root_item, 0);
 	btrfs_set_root_dirid(&root->root_item, 0);
 	if (is_fstree(objectid))
-		uuid_le_gen(&uuid);
-	memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
+		generate_random_guid(root->root_item.uuid);
+	else
+		export_guid(root->root_item.uuid, &guid_null);
 	root->root_item.drop_level = 0;
 
 	key.objectid = objectid;
@@ -1293,12 +1255,9 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	return root;
 
 fail:
-	if (leaf) {
+	if (leaf)
 		btrfs_tree_unlock(leaf);
-		free_extent_buffer(root->commit_root);
-		free_extent_buffer(leaf);
-	}
-	kfree(root);
+	btrfs_put_root(root);
 
 	return ERR_PTR(ret);
 }
@@ -1309,12 +1268,10 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	struct btrfs_root *root;
 	struct extent_buffer *leaf;
 
-	root = btrfs_alloc_root(fs_info, GFP_NOFS);
+	root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
-	__setup_root(root, fs_info, BTRFS_TREE_LOG_OBJECTID);
-
 	root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
@@ -1331,7 +1288,7 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
 			NULL, 0, 0, 0);
 	if (IS_ERR(leaf)) {
-		kfree(root);
+		btrfs_put_root(root);
 		return ERR_CAST(leaf);
 	}
 
@@ -1387,8 +1344,8 @@ int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 	return 0;
 }
 
-static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
-					       struct btrfs_key *key)
+struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
+					struct btrfs_key *key)
 {
 	struct btrfs_root *root;
 	struct btrfs_fs_info *fs_info = tree_root->fs_info;
@@ -1401,14 +1358,12 @@ static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
 	if (!path)
 		return ERR_PTR(-ENOMEM);
 
-	root = btrfs_alloc_root(fs_info, GFP_NOFS);
+	root = btrfs_alloc_root(fs_info, key->objectid, GFP_NOFS);
 	if (!root) {
 		ret = -ENOMEM;
 		goto alloc_fail;
 	}
 
-	__setup_root(root, fs_info, key->objectid);
-
 	ret = btrfs_find_root(tree_root, key, path,
 			      &root->root_item, &root->root_key);
 	if (ret) {
@@ -1424,10 +1379,10 @@ static struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
 				     generation, level, NULL);
 	if (IS_ERR(root->node)) {
 		ret = PTR_ERR(root->node);
+		root->node = NULL;
 		goto find_fail;
 	} else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
 		ret = -EIO;
-		free_extent_buffer(root->node);
 		goto find_fail;
 	}
 	root->commit_root = btrfs_root_node(root);
@@ -1436,33 +1391,16 @@ out:
 	return root;
 
 find_fail:
-	kfree(root);
+	btrfs_put_root(root);
 alloc_fail:
 	root = ERR_PTR(ret);
 	goto out;
 }
 
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
-				      struct btrfs_key *location)
-{
-	struct btrfs_root *root;
-
-	root = btrfs_read_tree_root(tree_root, location);
-	if (IS_ERR(root))
-		return root;
-
-	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-		set_bit(BTRFS_ROOT_REF_COWS, &root->state);
-		btrfs_check_and_init_root_item(&root->root_item);
-	}
-
-	return root;
-}
-
-int btrfs_init_fs_root(struct btrfs_root *root)
+static int btrfs_init_fs_root(struct btrfs_root *root)
 {
 	int ret;
-	struct btrfs_subvolume_writers *writers;
+	unsigned int nofs_flag;
 
 	root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
 	root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
@@ -1472,12 +1410,20 @@ int btrfs_init_fs_root(struct btrfs_root *root)
 		goto fail;
 	}
 
-	writers = btrfs_alloc_subvolume_writers();
-	if (IS_ERR(writers)) {
-		ret = PTR_ERR(writers);
+	/*
+	 * We might be called under a transaction (e.g. indirect backref
+	 * resolution) which could deadlock if it triggers memory reclaim
+	 */
+	nofs_flag = memalloc_nofs_save();
+	ret = btrfs_drew_lock_init(&root->snapshot_lock);
+	memalloc_nofs_restore(nofs_flag);
+	if (ret)
 		goto fail;
+
+	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+		set_bit(BTRFS_ROOT_REF_COWS, &root->state);
+		btrfs_check_and_init_root_item(&root->root_item);
 	}
-	root->subv_writers = writers;
 
 	btrfs_init_free_ino_ctl(root);
 	spin_lock_init(&root->ino_cache_lock);
@@ -1505,14 +1451,16 @@ fail:
 	return ret;
 }
 
-struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
-					u64 root_id)
+static struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
+					       u64 root_id)
 {
 	struct btrfs_root *root;
 
 	spin_lock(&fs_info->fs_roots_radix_lock);
 	root = radix_tree_lookup(&fs_info->fs_roots_radix,
 				 (unsigned long)root_id);
+	if (root)
+		root = btrfs_grab_root(root);
 	spin_unlock(&fs_info->fs_roots_radix_lock);
 	return root;
 }
@@ -1530,14 +1478,62 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
 	ret = radix_tree_insert(&fs_info->fs_roots_radix,
 				(unsigned long)root->root_key.objectid,
 				root);
-	if (ret == 0)
+	if (ret == 0) {
+		btrfs_grab_root(root);
 		set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
+	}
 	spin_unlock(&fs_info->fs_roots_radix_lock);
 	radix_tree_preload_end();
 
 	return ret;
 }
 
+void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
+{
+#ifdef CONFIG_BTRFS_DEBUG
+	struct btrfs_root *root;
+
+	while (!list_empty(&fs_info->allocated_roots)) {
+		root = list_first_entry(&fs_info->allocated_roots,
+					struct btrfs_root, leak_list);
+		btrfs_err(fs_info, "leaked root %llu-%llu refcount %d",
+			  root->root_key.objectid, root->root_key.offset,
+			  refcount_read(&root->refs));
+		while (refcount_read(&root->refs) > 1)
+			btrfs_put_root(root);
+		btrfs_put_root(root);
+	}
+#endif
+}
+
+void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
+{
+	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
+	percpu_counter_destroy(&fs_info->delalloc_bytes);
+	percpu_counter_destroy(&fs_info->dio_bytes);
+	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
+	btrfs_free_csum_hash(fs_info);
+	btrfs_free_stripe_hash_table(fs_info);
+	btrfs_free_ref_cache(fs_info);
+	kfree(fs_info->balance_ctl);
+	kfree(fs_info->delayed_root);
+	btrfs_put_root(fs_info->extent_root);
+	btrfs_put_root(fs_info->tree_root);
+	btrfs_put_root(fs_info->chunk_root);
+	btrfs_put_root(fs_info->dev_root);
+	btrfs_put_root(fs_info->csum_root);
+	btrfs_put_root(fs_info->quota_root);
+	btrfs_put_root(fs_info->uuid_root);
+	btrfs_put_root(fs_info->free_space_root);
+	btrfs_put_root(fs_info->fs_root);
+	btrfs_check_leaked_roots(fs_info);
+	btrfs_extent_buffer_leak_debug_check(fs_info);
+	kfree(fs_info->super_copy);
+	kfree(fs_info->super_for_commit);
+	kvfree(fs_info);
+}
+
+
 struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
 				     struct btrfs_key *location,
 				     bool check_ref)
@@ -1548,33 +1544,35 @@ struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
 	int ret;
 
 	if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
-		return fs_info->tree_root;
+		return btrfs_grab_root(fs_info->tree_root);
 	if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
-		return fs_info->extent_root;
+		return btrfs_grab_root(fs_info->extent_root);
 	if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
-		return fs_info->chunk_root;
+		return btrfs_grab_root(fs_info->chunk_root);
 	if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
-		return fs_info->dev_root;
+		return btrfs_grab_root(fs_info->dev_root);
 	if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
-		return fs_info->csum_root;
+		return btrfs_grab_root(fs_info->csum_root);
 	if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID)
-		return fs_info->quota_root ? fs_info->quota_root :
-					     ERR_PTR(-ENOENT);
+		return btrfs_grab_root(fs_info->quota_root) ?
+			fs_info->quota_root : ERR_PTR(-ENOENT);
 	if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
-		return fs_info->uuid_root ? fs_info->uuid_root :
-					    ERR_PTR(-ENOENT);
+		return btrfs_grab_root(fs_info->uuid_root) ?
+			fs_info->uuid_root : ERR_PTR(-ENOENT);
 	if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
-		return fs_info->free_space_root ? fs_info->free_space_root :
-						  ERR_PTR(-ENOENT);
+		return btrfs_grab_root(fs_info->free_space_root) ?
+			fs_info->free_space_root : ERR_PTR(-ENOENT);
 again:
 	root = btrfs_lookup_fs_root(fs_info, location->objectid);
 	if (root) {
-		if (check_ref && btrfs_root_refs(&root->root_item) == 0)
+		if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
+			btrfs_put_root(root);
 			return ERR_PTR(-ENOENT);
+		}
 		return root;
 	}
 
-	root = btrfs_read_fs_root(fs_info->tree_root, location);
+	root = btrfs_read_tree_root(fs_info->tree_root, location);
 	if (IS_ERR(root))
 		return root;
 
@@ -1605,15 +1603,14 @@ again:
 
 	ret = btrfs_insert_fs_root(fs_info, root);
 	if (ret) {
-		if (ret == -EEXIST) {
-			btrfs_free_fs_root(root);
+		btrfs_put_root(root);
+		if (ret == -EEXIST)
 			goto again;
-		}
 		goto fail;
 	}
 	return root;
 fail:
-	btrfs_free_fs_root(root);
+	btrfs_put_root(root);
 	return ERR_PTR(ret);
 }
 
@@ -1985,11 +1982,35 @@ static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
 	free_root_extent_buffers(info->csum_root);
 	free_root_extent_buffers(info->quota_root);
 	free_root_extent_buffers(info->uuid_root);
+	free_root_extent_buffers(info->fs_root);
 	if (free_chunk_root)
 		free_root_extent_buffers(info->chunk_root);
 	free_root_extent_buffers(info->free_space_root);
 }
 
+void btrfs_put_root(struct btrfs_root *root)
+{
+	if (!root)
+		return;
+
+	if (refcount_dec_and_test(&root->refs)) {
+		WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
+		if (root->anon_dev)
+			free_anon_bdev(root->anon_dev);
+		btrfs_drew_lock_destroy(&root->snapshot_lock);
+		free_extent_buffer(root->node);
+		free_extent_buffer(root->commit_root);
+		kfree(root->free_ino_ctl);
+		kfree(root->free_ino_pinned);
+#ifdef CONFIG_BTRFS_DEBUG
+		spin_lock(&root->fs_info->fs_roots_radix_lock);
+		list_del_init(&root->leak_list);
+		spin_unlock(&root->fs_info->fs_roots_radix_lock);
+#endif
+		kfree(root);
+	}
+}
+
 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
 {
 	int ret;
@@ -2001,13 +2022,9 @@ void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
 				     struct btrfs_root, root_list);
 		list_del(&gang[0]->root_list);
 
-		if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
+		if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state))
 			btrfs_drop_and_free_fs_root(fs_info, gang[0]);
-		} else {
-			free_extent_buffer(gang[0]->node);
-			free_extent_buffer(gang[0]->commit_root);
-			btrfs_put_fs_root(gang[0]);
-		}
+		btrfs_put_root(gang[0]);
 	}
 
 	while (1) {
@@ -2020,10 +2037,8 @@ void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
 			btrfs_drop_and_free_fs_root(fs_info, gang[i]);
 	}
 
-	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
+	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
 		btrfs_free_log_root_tree(NULL, fs_info);
-		btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
-	}
 }
 
 static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
@@ -2069,7 +2084,7 @@ static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
 
 	BTRFS_I(inode)->io_tree.ops = &btree_extent_io_ops;
 
-	BTRFS_I(inode)->root = fs_info->tree_root;
+	BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
 	memset(&BTRFS_I(inode)->location, 0, sizeof(struct btrfs_key));
 	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
 	btrfs_insert_inode_hash(inode);
@@ -2189,11 +2204,6 @@ static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
 	return 0;
 }
 
-static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
-{
-	crypto_free_shash(fs_info->csum_shash);
-}
-
 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 			    struct btrfs_fs_devices *fs_devices)
 {
@@ -2208,24 +2218,23 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 		return -EIO;
 	}
 
-	log_tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+	log_tree_root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID,
+					 GFP_KERNEL);
 	if (!log_tree_root)
 		return -ENOMEM;
 
-	__setup_root(log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
-
 	log_tree_root->node = read_tree_block(fs_info, bytenr,
 					      fs_info->generation + 1,
 					      level, NULL);
 	if (IS_ERR(log_tree_root->node)) {
 		btrfs_warn(fs_info, "failed to read log tree");
 		ret = PTR_ERR(log_tree_root->node);
-		kfree(log_tree_root);
+		log_tree_root->node = NULL;
+		btrfs_put_root(log_tree_root);
 		return ret;
 	} else if (!extent_buffer_uptodate(log_tree_root->node)) {
 		btrfs_err(fs_info, "failed to read log tree");
-		free_extent_buffer(log_tree_root->node);
-		kfree(log_tree_root);
+		btrfs_put_root(log_tree_root);
 		return -EIO;
 	}
 	/* returns with log_tree_root freed on success */
@@ -2233,8 +2242,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	if (ret) {
 		btrfs_handle_fs_error(fs_info, ret,
 				      "Failed to recover log tree");
-		free_extent_buffer(log_tree_root->node);
-		kfree(log_tree_root);
+		btrfs_put_root(log_tree_root);
 		return ret;
 	}
 
@@ -2624,67 +2632,8 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 	return ret;
 }
 
-int __cold open_ctree(struct super_block *sb,
-	       struct btrfs_fs_devices *fs_devices,
-	       char *options)
+void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
 {
-	u32 sectorsize;
-	u32 nodesize;
-	u32 stripesize;
-	u64 generation;
-	u64 features;
-	u16 csum_type;
-	struct btrfs_key location;
-	struct buffer_head *bh;
-	struct btrfs_super_block *disk_super;
-	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
-	struct btrfs_root *tree_root;
-	struct btrfs_root *chunk_root;
-	int ret;
-	int err = -EINVAL;
-	int clear_free_space_tree = 0;
-	int level;
-
-	tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
-	chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
-	if (!tree_root || !chunk_root) {
-		err = -ENOMEM;
-		goto fail;
-	}
-
-	ret = init_srcu_struct(&fs_info->subvol_srcu);
-	if (ret) {
-		err = ret;
-		goto fail;
-	}
-
-	ret = percpu_counter_init(&fs_info->dio_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_srcu;
-	}
-
-	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_dio_bytes;
-	}
-	fs_info->dirty_metadata_batch = PAGE_SIZE *
-					(1 + ilog2(nr_cpu_ids));
-
-	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_dirty_metadata_bytes;
-	}
-
-	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
-			GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_delalloc_bytes;
-	}
-
 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
 	INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
 	INIT_LIST_HEAD(&fs_info->trans_list);
@@ -2711,6 +2660,11 @@ int __cold open_ctree(struct super_block *sb,
 	INIT_LIST_HEAD(&fs_info->space_info);
 	INIT_LIST_HEAD(&fs_info->tree_mod_seq_list);
 	INIT_LIST_HEAD(&fs_info->unused_bgs);
+#ifdef CONFIG_BTRFS_DEBUG
+	INIT_LIST_HEAD(&fs_info->allocated_roots);
+	INIT_LIST_HEAD(&fs_info->allocated_ebs);
+	spin_lock_init(&fs_info->eb_leak_lock);
+#endif
 	extent_map_tree_init(&fs_info->mapping_tree);
 	btrfs_init_block_rsv(&fs_info->global_block_rsv,
 			     BTRFS_BLOCK_RSV_GLOBAL);
@@ -2727,7 +2681,6 @@ int __cold open_ctree(struct super_block *sb,
 	atomic_set(&fs_info->reada_works_cnt, 0);
 	atomic_set(&fs_info->nr_delayed_iputs, 0);
 	atomic64_set(&fs_info->tree_mod_seq, 0);
-	fs_info->sb = sb;
 	fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE;
 	fs_info->metadata_ratio = 0;
 	fs_info->defrag_inodes = RB_ROOT;
@@ -2746,21 +2699,6 @@ int __cold open_ctree(struct super_block *sb,
 	INIT_LIST_HEAD(&fs_info->ordered_roots);
 	spin_lock_init(&fs_info->ordered_root_lock);
 
-	fs_info->btree_inode = new_inode(sb);
-	if (!fs_info->btree_inode) {
-		err = -ENOMEM;
-		goto fail_bio_counter;
-	}
-	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
-
-	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
-					GFP_KERNEL);
-	if (!fs_info->delayed_root) {
-		err = -ENOMEM;
-		goto fail_iput;
-	}
-	btrfs_init_delayed_root(fs_info->delayed_root);
-
 	btrfs_init_scrub(fs_info);
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 	fs_info->check_integrity_print_mask = 0;
@@ -2768,20 +2706,12 @@ int __cold open_ctree(struct super_block *sb,
 	btrfs_init_balance(fs_info);
 	btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
 
-	sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
-	sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
-
-	btrfs_init_btree_inode(fs_info);
-
 	spin_lock_init(&fs_info->block_group_cache_lock);
 	fs_info->block_group_cache_tree = RB_ROOT;
 	fs_info->first_logical_byte = (u64)-1;
 
-	extent_io_tree_init(fs_info, &fs_info->freed_extents[0],
-			    IO_TREE_FS_INFO_FREED_EXTENTS0, NULL);
-	extent_io_tree_init(fs_info, &fs_info->freed_extents[1],
-			    IO_TREE_FS_INFO_FREED_EXTENTS1, NULL);
-	fs_info->pinned_extents = &fs_info->freed_extents[0];
+	extent_io_tree_init(fs_info, &fs_info->excluded_extents,
+			    IO_TREE_FS_EXCLUDED_EXTENTS, NULL);
 	set_bit(BTRFS_FS_BARRIER, &fs_info->flags);
 
 	mutex_init(&fs_info->ordered_operations_mutex);
@@ -2817,23 +2747,135 @@ int __cold open_ctree(struct super_block *sb,
 	fs_info->swapfile_pins = RB_ROOT;
 
 	fs_info->send_in_progress = 0;
+}
+
+static int init_mount_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
+{
+	int ret;
+
+	fs_info->sb = sb;
+	sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
+	sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
+
+	ret = percpu_counter_init(&fs_info->dio_bytes, 0, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	fs_info->dirty_metadata_batch = PAGE_SIZE *
+					(1 + ilog2(nr_cpu_ids));
+
+	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
+			GFP_KERNEL);
+	if (ret)
+		return ret;
 
-	ret = btrfs_alloc_stripe_hash_table(fs_info);
+	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+					GFP_KERNEL);
+	if (!fs_info->delayed_root)
+		return -ENOMEM;
+	btrfs_init_delayed_root(fs_info->delayed_root);
+
+	return btrfs_alloc_stripe_hash_table(fs_info);
+}
+
+static int btrfs_uuid_rescan_kthread(void *data)
+{
+	struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
+	int ret;
+
+	/*
+	 * 1st step is to iterate through the existing UUID tree and
+	 * to delete all entries that contain outdated data.
+	 * 2nd step is to add all missing entries to the UUID tree.
+	 */
+	ret = btrfs_uuid_tree_iterate(fs_info);
+	if (ret < 0) {
+		if (ret != -EINTR)
+			btrfs_warn(fs_info, "iterating uuid_tree failed %d",
+				   ret);
+		up(&fs_info->uuid_tree_rescan_sem);
+		return ret;
+	}
+	return btrfs_uuid_scan_kthread(data);
+}
+
+static int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
+{
+	struct task_struct *task;
+
+	down(&fs_info->uuid_tree_rescan_sem);
+	task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
+	if (IS_ERR(task)) {
+		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
+		btrfs_warn(fs_info, "failed to start uuid_rescan task");
+		up(&fs_info->uuid_tree_rescan_sem);
+		return PTR_ERR(task);
+	}
+
+	return 0;
+}
+
+int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
+		      char *options)
+{
+	u32 sectorsize;
+	u32 nodesize;
+	u32 stripesize;
+	u64 generation;
+	u64 features;
+	u16 csum_type;
+	struct btrfs_key location;
+	struct btrfs_super_block *disk_super;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *tree_root;
+	struct btrfs_root *chunk_root;
+	int ret;
+	int err = -EINVAL;
+	int clear_free_space_tree = 0;
+	int level;
+
+	ret = init_mount_fs_info(fs_info, sb);
 	if (ret) {
 		err = ret;
-		goto fail_alloc;
+		goto fail;
 	}
 
-	__setup_root(tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
+	/* These need to be init'ed before we start creating inodes and such. */
+	tree_root = btrfs_alloc_root(fs_info, BTRFS_ROOT_TREE_OBJECTID,
+				     GFP_KERNEL);
+	fs_info->tree_root = tree_root;
+	chunk_root = btrfs_alloc_root(fs_info, BTRFS_CHUNK_TREE_OBJECTID,
+				      GFP_KERNEL);
+	fs_info->chunk_root = chunk_root;
+	if (!tree_root || !chunk_root) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	fs_info->btree_inode = new_inode(sb);
+	if (!fs_info->btree_inode) {
+		err = -ENOMEM;
+		goto fail;
+	}
+	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
+	btrfs_init_btree_inode(fs_info);
 
 	invalidate_bdev(fs_devices->latest_bdev);
 
 	/*
 	 * Read super block and check the signature bytes only
 	 */
-	bh = btrfs_read_dev_super(fs_devices->latest_bdev);
-	if (IS_ERR(bh)) {
-		err = PTR_ERR(bh);
+	disk_super = btrfs_read_dev_super(fs_devices->latest_bdev);
+	if (IS_ERR(disk_super)) {
+		err = PTR_ERR(disk_super);
 		goto fail_alloc;
 	}
 
@@ -2841,18 +2883,19 @@ int __cold open_ctree(struct super_block *sb,
 	 * Verify the type first, if that or the the checksum value are
 	 * corrupted, we'll find out
 	 */
-	csum_type = btrfs_super_csum_type((struct btrfs_super_block *)bh->b_data);
+	csum_type = btrfs_super_csum_type(disk_super);
 	if (!btrfs_supported_super_csum(csum_type)) {
 		btrfs_err(fs_info, "unsupported checksum algorithm: %u",
 			  csum_type);
 		err = -EINVAL;
-		brelse(bh);
+		btrfs_release_disk_super(disk_super);
 		goto fail_alloc;
 	}
 
 	ret = btrfs_init_csum_hash(fs_info, csum_type);
 	if (ret) {
 		err = ret;
+		btrfs_release_disk_super(disk_super);
 		goto fail_alloc;
 	}
 
@@ -2860,11 +2903,11 @@ int __cold open_ctree(struct super_block *sb,
 	 * We want to check superblock checksum, the type is stored inside.
 	 * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
 	 */
-	if (btrfs_check_super_csum(fs_info, bh->b_data)) {
+	if (btrfs_check_super_csum(fs_info, (u8 *)disk_super)) {
 		btrfs_err(fs_info, "superblock checksum mismatch");
 		err = -EINVAL;
-		brelse(bh);
-		goto fail_csum;
+		btrfs_release_disk_super(disk_super);
+		goto fail_alloc;
 	}
 
 	/*
@@ -2872,8 +2915,8 @@ int __cold open_ctree(struct super_block *sb,
 	 * following bytes up to INFO_SIZE, the checksum is calculated from
 	 * the whole block of INFO_SIZE
 	 */
-	memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
-	brelse(bh);
+	memcpy(fs_info->super_copy, disk_super, sizeof(*fs_info->super_copy));
+	btrfs_release_disk_super(disk_super);
 
 	disk_super = fs_info->super_copy;
 
@@ -2901,11 +2944,11 @@ int __cold open_ctree(struct super_block *sb,
 	if (ret) {
 		btrfs_err(fs_info, "superblock contains fatal errors");
 		err = -EINVAL;
-		goto fail_csum;
+		goto fail_alloc;
 	}
 
 	if (!btrfs_super_root(disk_super))
-		goto fail_csum;
+		goto fail_alloc;
 
 	/* check FS state, whether FS is broken. */
 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
@@ -2920,7 +2963,7 @@ int __cold open_ctree(struct super_block *sb,
 	ret = btrfs_parse_options(fs_info, options, sb->s_flags);
 	if (ret) {
 		err = ret;
-		goto fail_csum;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super) &
@@ -2930,7 +2973,7 @@ int __cold open_ctree(struct super_block *sb,
 		    "cannot mount because of unsupported optional features (%llx)",
 		    features);
 		err = -EINVAL;
-		goto fail_csum;
+		goto fail_alloc;
 	}
 
 	features = btrfs_super_incompat_flags(disk_super);
@@ -2974,7 +3017,7 @@ int __cold open_ctree(struct super_block *sb,
 		btrfs_err(fs_info,
 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
 			nodesize, sectorsize);
-		goto fail_csum;
+		goto fail_alloc;
 	}
 
 	/*
@@ -2990,7 +3033,7 @@ int __cold open_ctree(struct super_block *sb,
 	"cannot mount read-write because of unsupported optional features (%llx)",
 		       features);
 		err = -EINVAL;
-		goto fail_csum;
+		goto fail_alloc;
 	}
 
 	ret = btrfs_init_workqueues(fs_info, fs_devices);
@@ -3021,8 +3064,6 @@ int __cold open_ctree(struct super_block *sb,
 	generation = btrfs_super_chunk_root_generation(disk_super);
 	level = btrfs_super_chunk_root_level(disk_super);
 
-	__setup_root(chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
-
 	chunk_root->node = read_tree_block(fs_info,
 					   btrfs_super_chunk_root(disk_super),
 					   generation, level, NULL);
@@ -3038,7 +3079,8 @@ int __cold open_ctree(struct super_block *sb,
 	chunk_root->commit_root = btrfs_root_node(chunk_root);
 
 	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
-	   btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE);
+			   offsetof(struct btrfs_header, chunk_tree_uuid),
+			   BTRFS_UUID_SIZE);
 
 	ret = btrfs_read_chunk_tree(fs_info);
 	if (ret) {
@@ -3061,6 +3103,18 @@ int __cold open_ctree(struct super_block *sb,
 	if (ret)
 		goto fail_tree_roots;
 
+	/*
+	 * If we have a uuid root and we're not being told to rescan we need to
+	 * check the generation here so we can set the
+	 * BTRFS_FS_UPDATE_UUID_TREE_GEN bit.  Otherwise we could commit the
+	 * transaction during a balance or the log replay without updating the
+	 * uuid generation, and then if we crash we would rescan the uuid tree,
+	 * even though it was perfectly fine.
+	 */
+	if (fs_info->uuid_root && !btrfs_test_opt(fs_info, RESCAN_UUID_TREE) &&
+	    fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
+		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
+
 	ret = btrfs_verify_dev_extents(fs_info);
 	if (ret) {
 		btrfs_err(fs_info,
@@ -3196,7 +3250,7 @@ int __cold open_ctree(struct super_block *sb,
 	location.type = BTRFS_ROOT_ITEM_KEY;
 	location.offset = 0;
 
-	fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
+	fs_info->fs_root = btrfs_get_fs_root(fs_info, &location, true);
 	if (IS_ERR(fs_info->fs_root)) {
 		err = PTR_ERR(fs_info->fs_root);
 		btrfs_warn(fs_info, "failed to read fs tree: %d", err);
@@ -3285,8 +3339,6 @@ int __cold open_ctree(struct super_block *sb,
 			close_ctree(fs_info);
 			return ret;
 		}
-	} else {
-		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
 	}
 	set_bit(BTRFS_FS_OPEN, &fs_info->flags);
 
@@ -3329,90 +3381,78 @@ fail_tree_roots:
 fail_sb_buffer:
 	btrfs_stop_all_workers(fs_info);
 	btrfs_free_block_groups(fs_info);
-fail_csum:
-	btrfs_free_csum_hash(fs_info);
 fail_alloc:
-fail_iput:
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
 	iput(fs_info->btree_inode);
-fail_bio_counter:
-	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
-fail_delalloc_bytes:
-	percpu_counter_destroy(&fs_info->delalloc_bytes);
-fail_dirty_metadata_bytes:
-	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
-fail_dio_bytes:
-	percpu_counter_destroy(&fs_info->dio_bytes);
-fail_srcu:
-	cleanup_srcu_struct(&fs_info->subvol_srcu);
 fail:
-	btrfs_free_stripe_hash_table(fs_info);
 	btrfs_close_devices(fs_info->fs_devices);
 	return err;
 }
 ALLOW_ERROR_INJECTION(open_ctree, ERRNO);
 
-static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
+static void btrfs_end_super_write(struct bio *bio)
 {
-	if (uptodate) {
-		set_buffer_uptodate(bh);
-	} else {
-		struct btrfs_device *device = (struct btrfs_device *)
-			bh->b_private;
-
-		btrfs_warn_rl_in_rcu(device->fs_info,
-				"lost page write due to IO error on %s",
-					  rcu_str_deref(device->name));
-		/* note, we don't set_buffer_write_io_error because we have
-		 * our own ways of dealing with the IO errors
-		 */
-		clear_buffer_uptodate(bh);
-		btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS);
+	struct btrfs_device *device = bio->bi_private;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+	struct page *page;
+
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		page = bvec->bv_page;
+
+		if (bio->bi_status) {
+			btrfs_warn_rl_in_rcu(device->fs_info,
+				"lost page write due to IO error on %s (%d)",
+				rcu_str_deref(device->name),
+				blk_status_to_errno(bio->bi_status));
+			ClearPageUptodate(page);
+			SetPageError(page);
+			btrfs_dev_stat_inc_and_print(device,
+						     BTRFS_DEV_STAT_WRITE_ERRS);
+		} else {
+			SetPageUptodate(page);
+		}
+
+		put_page(page);
+		unlock_page(page);
 	}
-	unlock_buffer(bh);
-	put_bh(bh);
+
+	bio_put(bio);
 }
 
-int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
-			struct buffer_head **bh_ret)
+struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
+						   int copy_num)
 {
-	struct buffer_head *bh;
 	struct btrfs_super_block *super;
+	struct page *page;
 	u64 bytenr;
+	struct address_space *mapping = bdev->bd_inode->i_mapping;
 
 	bytenr = btrfs_sb_offset(copy_num);
 	if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 
-	bh = __bread(bdev, bytenr / BTRFS_BDEV_BLOCKSIZE, BTRFS_SUPER_INFO_SIZE);
-	/*
-	 * If we fail to read from the underlying devices, as of now
-	 * the best option we have is to mark it EIO.
-	 */
-	if (!bh)
-		return -EIO;
+	page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
+	if (IS_ERR(page))
+		return ERR_CAST(page);
 
-	super = (struct btrfs_super_block *)bh->b_data;
+	super = page_address(page);
 	if (btrfs_super_bytenr(super) != bytenr ||
 		    btrfs_super_magic(super) != BTRFS_MAGIC) {
-		brelse(bh);
-		return -EINVAL;
+		btrfs_release_disk_super(super);
+		return ERR_PTR(-EINVAL);
 	}
 
-	*bh_ret = bh;
-	return 0;
+	return super;
 }
 
 
-struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
+struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev)
 {
-	struct buffer_head *bh;
-	struct buffer_head *latest = NULL;
-	struct btrfs_super_block *super;
+	struct btrfs_super_block *super, *latest = NULL;
 	int i;
 	u64 transid = 0;
-	int ret = -EINVAL;
 
 	/* we would like to check all the supers, but that would make
 	 * a btrfs mount succeed after a mkfs from a different FS.
@@ -3420,48 +3460,41 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
 	 */
 	for (i = 0; i < 1; i++) {
-		ret = btrfs_read_dev_one_super(bdev, i, &bh);
-		if (ret)
+		super = btrfs_read_dev_one_super(bdev, i);
+		if (IS_ERR(super))
 			continue;
 
-		super = (struct btrfs_super_block *)bh->b_data;
-
 		if (!latest || btrfs_super_generation(super) > transid) {
-			brelse(latest);
-			latest = bh;
+			if (latest)
+				btrfs_release_disk_super(super);
+
+			latest = super;
 			transid = btrfs_super_generation(super);
-		} else {
-			brelse(bh);
 		}
 	}
 
-	if (!latest)
-		return ERR_PTR(ret);
-
-	return latest;
+	return super;
 }
 
 /*
  * Write superblock @sb to the @device. Do not wait for completion, all the
- * buffer heads we write are pinned.
+ * pages we use for writing are locked.
  *
  * Write @max_mirrors copies of the superblock, where 0 means default that fit
  * the expected device size at commit time. Note that max_mirrors must be
  * same for write and wait phases.
  *
- * Return number of errors when buffer head is not found or submission fails.
+ * Return number of errors when page is not found or submission fails.
  */
 static int write_dev_supers(struct btrfs_device *device,
 			    struct btrfs_super_block *sb, int max_mirrors)
 {
 	struct btrfs_fs_info *fs_info = device->fs_info;
+	struct address_space *mapping = device->bdev->bd_inode->i_mapping;
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
-	struct buffer_head *bh;
 	int i;
-	int ret;
 	int errors = 0;
 	u64 bytenr;
-	int op_flags;
 
 	if (max_mirrors == 0)
 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
@@ -3469,6 +3502,10 @@ static int write_dev_supers(struct btrfs_device *device,
 	shash->tfm = fs_info->csum_shash;
 
 	for (i = 0; i < max_mirrors; i++) {
+		struct page *page;
+		struct bio *bio;
+		struct btrfs_super_block *disk_super;
+
 		bytenr = btrfs_sb_offset(i);
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
 		    device->commit_total_bytes)
@@ -3481,37 +3518,45 @@ static int write_dev_supers(struct btrfs_device *device,
 				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 		crypto_shash_final(shash, sb->csum);
 
-		/* One reference for us, and we leave it for the caller */
-		bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
-			      BTRFS_SUPER_INFO_SIZE);
-		if (!bh) {
+		page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
+					   GFP_NOFS);
+		if (!page) {
 			btrfs_err(device->fs_info,
-			    "couldn't get super buffer head for bytenr %llu",
+			    "couldn't get super block page for bytenr %llu",
 			    bytenr);
 			errors++;
 			continue;
 		}
 
-		memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
+		/* Bump the refcount for wait_dev_supers() */
+		get_page(page);
 
-		/* one reference for submit_bh */
-		get_bh(bh);
+		disk_super = page_address(page);
+		memcpy(disk_super, sb, BTRFS_SUPER_INFO_SIZE);
 
-		set_buffer_uptodate(bh);
-		lock_buffer(bh);
-		bh->b_end_io = btrfs_end_buffer_write_sync;
-		bh->b_private = device;
+		/*
+		 * Directly use bios here instead of relying on the page cache
+		 * to do I/O, so we don't lose the ability to do integrity
+		 * checking.
+		 */
+		bio = bio_alloc(GFP_NOFS, 1);
+		bio_set_dev(bio, device->bdev);
+		bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT;
+		bio->bi_private = device;
+		bio->bi_end_io = btrfs_end_super_write;
+		__bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE,
+			       offset_in_page(bytenr));
 
 		/*
-		 * we fua the first super.  The others we allow
-		 * to go down lazy.
+		 * We FUA only the first super block.  The others we allow to
+		 * go down lazy and there's a short window where the on-disk
+		 * copies might still contain the older version.
 		 */
-		op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
+		bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META | REQ_PRIO;
 		if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER))
-			op_flags |= REQ_FUA;
-		ret = btrfsic_submit_bh(REQ_OP_WRITE, op_flags, bh);
-		if (ret)
-			errors++;
+			bio->bi_opf |= REQ_FUA;
+
+		btrfsic_submit_bio(bio);
 	}
 	return errors < i ? 0 : -1;
 }
@@ -3520,12 +3565,11 @@ static int write_dev_supers(struct btrfs_device *device,
  * Wait for write completion of superblocks done by write_dev_supers,
  * @max_mirrors same for write and wait phases.
  *
- * Return number of errors when buffer head is not found or not marked up to
+ * Return number of errors when page is not found or not marked up to
  * date.
  */
 static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
 {
-	struct buffer_head *bh;
 	int i;
 	int errors = 0;
 	bool primary_failed = false;
@@ -3535,32 +3579,34 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
 
 	for (i = 0; i < max_mirrors; i++) {
+		struct page *page;
+
 		bytenr = btrfs_sb_offset(i);
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
 		    device->commit_total_bytes)
 			break;
 
-		bh = __find_get_block(device->bdev,
-				      bytenr / BTRFS_BDEV_BLOCKSIZE,
-				      BTRFS_SUPER_INFO_SIZE);
-		if (!bh) {
+		page = find_get_page(device->bdev->bd_inode->i_mapping,
+				     bytenr >> PAGE_SHIFT);
+		if (!page) {
 			errors++;
 			if (i == 0)
 				primary_failed = true;
 			continue;
 		}
-		wait_on_buffer(bh);
-		if (!buffer_uptodate(bh)) {
+		/* Page is submitted locked and unlocked once the IO completes */
+		wait_on_page_locked(page);
+		if (PageError(page)) {
 			errors++;
 			if (i == 0)
 				primary_failed = true;
 		}
 
-		/* drop our reference */
-		brelse(bh);
+		/* Drop our reference */
+		put_page(page);
 
-		/* drop the reference from the writing run */
-		brelse(bh);
+		/* Drop the reference from the writing run */
+		put_page(page);
 	}
 
 	/* log error, force error return */
@@ -3832,20 +3878,19 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors)
 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
 				  struct btrfs_root *root)
 {
+	bool drop_ref = false;
+
 	spin_lock(&fs_info->fs_roots_radix_lock);
 	radix_tree_delete(&fs_info->fs_roots_radix,
 			  (unsigned long)root->root_key.objectid);
+	if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state))
+		drop_ref = true;
 	spin_unlock(&fs_info->fs_roots_radix_lock);
 
-	if (btrfs_root_refs(&root->root_item) == 0)
-		synchronize_srcu(&fs_info->subvol_srcu);
-
 	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
 		btrfs_free_log(NULL, root);
 		if (root->reloc_root) {
-			free_extent_buffer(root->reloc_root->node);
-			free_extent_buffer(root->reloc_root->commit_root);
-			btrfs_put_fs_root(root->reloc_root);
+			btrfs_put_root(root->reloc_root);
 			root->reloc_root = NULL;
 		}
 	}
@@ -3854,22 +3899,12 @@ void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
 		__btrfs_remove_free_space_cache(root->free_ino_pinned);
 	if (root->free_ino_ctl)
 		__btrfs_remove_free_space_cache(root->free_ino_ctl);
-	btrfs_free_fs_root(root);
-}
-
-void btrfs_free_fs_root(struct btrfs_root *root)
-{
-	iput(root->ino_cache_inode);
-	WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
-	if (root->anon_dev)
-		free_anon_bdev(root->anon_dev);
-	if (root->subv_writers)
-		btrfs_free_subvolume_writers(root->subv_writers);
-	free_extent_buffer(root->node);
-	free_extent_buffer(root->commit_root);
-	kfree(root->free_ino_ctl);
-	kfree(root->free_ino_pinned);
-	btrfs_put_fs_root(root);
+	if (root->ino_cache_inode) {
+		iput(root->ino_cache_inode);
+		root->ino_cache_inode = NULL;
+	}
+	if (drop_ref)
+		btrfs_put_root(root);
 }
 
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
@@ -3879,15 +3914,14 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 	int i = 0;
 	int err = 0;
 	unsigned int ret = 0;
-	int index;
 
 	while (1) {
-		index = srcu_read_lock(&fs_info->subvol_srcu);
+		spin_lock(&fs_info->fs_roots_radix_lock);
 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 					     (void **)gang, root_objectid,
 					     ARRAY_SIZE(gang));
 		if (!ret) {
-			srcu_read_unlock(&fs_info->subvol_srcu, index);
+			spin_unlock(&fs_info->fs_roots_radix_lock);
 			break;
 		}
 		root_objectid = gang[ret - 1]->root_key.objectid + 1;
@@ -3899,9 +3933,9 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 				continue;
 			}
 			/* grab all the search result for later use */
-			gang[i] = btrfs_grab_fs_root(gang[i]);
+			gang[i] = btrfs_grab_root(gang[i]);
 		}
-		srcu_read_unlock(&fs_info->subvol_srcu, index);
+		spin_unlock(&fs_info->fs_roots_radix_lock);
 
 		for (i = 0; i < ret; i++) {
 			if (!gang[i])
@@ -3910,7 +3944,7 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 			err = btrfs_orphan_cleanup(gang[i]);
 			if (err)
 				break;
-			btrfs_put_fs_root(gang[i]);
+			btrfs_put_root(gang[i]);
 		}
 		root_objectid++;
 	}
@@ -3918,7 +3952,7 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 	/* release the uncleaned roots due to error */
 	for (; i < ret; i++) {
 		if (gang[i])
-			btrfs_put_fs_root(gang[i]);
+			btrfs_put_root(gang[i]);
 	}
 	return err;
 }
@@ -3990,6 +4024,19 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 		 */
 		btrfs_delete_unused_bgs(fs_info);
 
+		/*
+		 * There might be existing delayed inode workers still running
+		 * and holding an empty delayed inode item. We must wait for
+		 * them to complete first because they can create a transaction.
+		 * This happens when someone calls btrfs_balance_delayed_items()
+		 * and then a transaction commit runs the same delayed nodes
+		 * before any delayed worker has done something with the nodes.
+		 * We must wait for any worker here and not at transaction
+		 * commit time since that could cause a deadlock.
+		 * This is a very rare case.
+		 */
+		btrfs_flush_workqueue(fs_info->delayed_workers);
+
 		ret = btrfs_commit_super(fs_info);
 		if (ret)
 			btrfs_err(fs_info, "commit super ret %d", ret);
@@ -4020,8 +4067,6 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 	btrfs_sysfs_remove_mounted(fs_info);
 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
 
-	btrfs_free_fs_roots(fs_info);
-
 	btrfs_put_block_group_cache(fs_info);
 
 	/*
@@ -4033,6 +4078,7 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 
 	clear_bit(BTRFS_FS_OPEN, &fs_info->flags);
 	free_root_pointers(fs_info, true);
+	btrfs_free_fs_roots(fs_info);
 
 	/*
 	 * We must free the block groups after dropping the fs_roots as we could
@@ -4052,16 +4098,6 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info)
 
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 	btrfs_close_devices(fs_info->fs_devices);
-
-	percpu_counter_destroy(&fs_info->dirty_metadata_bytes);
-	percpu_counter_destroy(&fs_info->delalloc_bytes);
-	percpu_counter_destroy(&fs_info->dio_bytes);
-	percpu_counter_destroy(&fs_info->dev_replace.bio_counter);
-	cleanup_srcu_struct(&fs_info->subvol_srcu);
-
-	btrfs_free_csum_hash(fs_info);
-	btrfs_free_stripe_hash_table(fs_info);
-	btrfs_free_ref_cache(fs_info);
 }
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
@@ -4235,7 +4271,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 	spin_lock(&delayed_refs->lock);
 	if (atomic_read(&delayed_refs->num_entries) == 0) {
 		spin_unlock(&delayed_refs->lock);
-		btrfs_info(fs_info, "delayed_refs has NO entry");
+		btrfs_debug(fs_info, "delayed_refs has NO entry");
 		return ret;
 	}
 
@@ -4269,9 +4305,30 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 		spin_unlock(&delayed_refs->lock);
 		mutex_unlock(&head->mutex);
 
-		if (pin_bytes)
-			btrfs_pin_extent(fs_info, head->bytenr,
-					 head->num_bytes, 1);
+		if (pin_bytes) {
+			struct btrfs_block_group *cache;
+
+			cache = btrfs_lookup_block_group(fs_info, head->bytenr);
+			BUG_ON(!cache);
+
+			spin_lock(&cache->space_info->lock);
+			spin_lock(&cache->lock);
+			cache->pinned += head->num_bytes;
+			btrfs_space_info_update_bytes_pinned(fs_info,
+				cache->space_info, head->num_bytes);
+			cache->reserved -= head->num_bytes;
+			cache->space_info->bytes_reserved -= head->num_bytes;
+			spin_unlock(&cache->lock);
+			spin_unlock(&cache->space_info->lock);
+			percpu_counter_add_batch(
+				&cache->space_info->total_bytes_pinned,
+				head->num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
+
+			btrfs_put_block_group(cache);
+
+			btrfs_error_unpin_extent_range(fs_info, head->bytenr,
+				head->bytenr + head->num_bytes - 1);
+		}
 		btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head);
 		btrfs_put_delayed_ref_head(head);
 		cond_resched();
@@ -4327,12 +4384,12 @@ static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
 	while (!list_empty(&splice)) {
 		root = list_first_entry(&splice, struct btrfs_root,
 					 delalloc_root);
-		root = btrfs_grab_fs_root(root);
+		root = btrfs_grab_root(root);
 		BUG_ON(!root);
 		spin_unlock(&fs_info->delalloc_root_lock);
 
 		btrfs_destroy_delalloc_inodes(root);
-		btrfs_put_fs_root(root);
+		btrfs_put_root(root);
 
 		spin_lock(&fs_info->delalloc_root_lock);
 	}
@@ -4373,16 +4430,12 @@ static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
 }
 
 static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
-				       struct extent_io_tree *pinned_extents)
+				       struct extent_io_tree *unpin)
 {
-	struct extent_io_tree *unpin;
 	u64 start;
 	u64 end;
 	int ret;
-	bool loop = true;
 
-	unpin = pinned_extents;
-again:
 	while (1) {
 		struct extent_state *cached_state = NULL;
 
@@ -4407,15 +4460,6 @@ again:
 		cond_resched();
 	}
 
-	if (loop) {
-		if (unpin == &fs_info->freed_extents[0])
-			unpin = &fs_info->freed_extents[1];
-		else
-			unpin = &fs_info->freed_extents[0];
-		loop = false;
-		goto again;
-	}
-
 	return 0;
 }
 
@@ -4506,8 +4550,7 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 
 	btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
 				     EXTENT_DIRTY);
-	btrfs_destroy_pinned_extent(fs_info,
-				    fs_info->pinned_extents);
+	btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
 
 	cur_trans->state =TRANS_STATE_COMPLETED;
 	wake_up(&cur_trans->commit_wait);
@@ -4559,7 +4602,6 @@ static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
 	btrfs_destroy_all_ordered_extents(fs_info);
 	btrfs_destroy_delayed_inodes(fs_info);
 	btrfs_assert_delayed_root_empty(fs_info);
-	btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
 	btrfs_destroy_all_delalloc_inodes(fs_info);
 	mutex_unlock(&fs_info->transaction_kthread_mutex);