diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 8d432cd9d580d39ed2e94bf3be99c17667a8b0dd..2222d161c7b68111431031e007b019d7de629d3e 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -60,6 +60,8 @@ static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
 		size = __btrfs_getxattr(inode, name, value, size);
 		if (size > 0) {
 			acl = posix_acl_from_xattr(value, size);
+			if (IS_ERR(acl))
+				return acl;
 			set_cached_acl(inode, type, acl);
 		}
 		kfree(value);
@@ -160,6 +162,12 @@ static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
 	int ret;
 	struct posix_acl *acl = NULL;
 
+	if (!is_owner_or_cap(dentry->d_inode))
+		return -EPERM;
+
+	if (!IS_POSIXACL(dentry->d_inode))
+		return -EOPNOTSUPP;
+
 	if (value) {
 		acl = posix_acl_from_xattr(value, size);
 		if (acl == NULL) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f3b287c22caf2e6855cf89bf780cf0b4b675c902..34f7c375567e38eef3f83843baf0bf2272282008 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1941,8 +1941,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		     btrfs_level_size(tree_root,
 				      btrfs_super_log_root_level(disk_super));
 
-		log_tree_root = kzalloc(sizeof(struct btrfs_root),
-						      GFP_NOFS);
+		log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
+		if (!log_tree_root) {
+			err = -ENOMEM;
+			goto fail_trans_kthread;
+		}
 
 		__setup_root(nodesize, leafsize, sectorsize, stripesize,
 			     log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
@@ -1982,6 +1985,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
 	if (!fs_info->fs_root)
 		goto fail_trans_kthread;
+	if (IS_ERR(fs_info->fs_root)) {
+		err = PTR_ERR(fs_info->fs_root);
+		goto fail_trans_kthread;
+	}
 
 	if (!(sb->s_flags & MS_RDONLY)) {
 		down_read(&fs_info->cleanup_work_sem);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b9080d71991a35cea63d2620d1534234cde6e0a9..32d094002a57132b2113e9e8f02303f6a8b16052 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4360,7 +4360,8 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 
 	block_rsv = get_block_rsv(trans, root);
 	cache = btrfs_lookup_block_group(root->fs_info, buf->start);
-	BUG_ON(block_rsv->space_info != cache->space_info);
+	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) {
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 787b50a16a146eea9bb4ec4202fcdab1f3f4bec0..e354c33df0824592bb9356be4987fd0ddfbbdc71 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1140,7 +1140,7 @@ int btrfs_sync_file(struct file *file, int datasync)
 	/*
 	 * ok we haven't committed the transaction yet, lets do a commit
 	 */
-	if (file && file->private_data)
+	if (file->private_data)
 		btrfs_ioctl_trans_end(file);
 
 	trans = btrfs_start_transaction(root, 0);
@@ -1190,14 +1190,22 @@ static const struct vm_operations_struct btrfs_file_vm_ops = {
 
 static int btrfs_file_mmap(struct file	*filp, struct vm_area_struct *vma)
 {
-	vma->vm_ops = &btrfs_file_vm_ops;
+	struct address_space *mapping = filp->f_mapping;
+
+	if (!mapping->a_ops->readpage)
+		return -ENOEXEC;
+
 	file_accessed(filp);
+	vma->vm_ops = &btrfs_file_vm_ops;
+	vma->vm_flags |= VM_CAN_NONLINEAR;
+
 	return 0;
 }
 
 const struct file_operations btrfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
+	.write		= do_sync_write,
 	.aio_read       = generic_file_aio_read,
 	.splice_read	= generic_file_splice_read,
 	.aio_write	= btrfs_file_aio_write,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fa6ccc1bfe2a9a73e2de97ed04cac8708efa99f9..1bff92ad474434a535b711abebb14d7a692cabca 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2673,7 +2673,7 @@ static int check_path_shared(struct btrfs_root *root,
 	struct extent_buffer *eb;
 	int level;
 	int ret;
-	u64 refs;
+	u64 refs = 1;
 
 	for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
 		if (!path->nodes[level])
@@ -6884,7 +6884,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
 		if (em->block_start == EXTENT_MAP_HOLE ||
 		    (cur_offset >= inode->i_size &&
 		     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
-			ret = btrfs_prealloc_file_range(inode, 0, cur_offset,
+			ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
 							last_byte - cur_offset,
 							1 << inode->i_blkbits,
 							offset + len,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4cdb98cf26de174e644e7d74e2a97e2fe037f08b..4dbaf89b1337632ac7800b84b183d6cd0ab14242 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1280,7 +1280,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
 		err = PTR_ERR(trans);
-		goto out;
+		goto out_up_write;
 	}
 	trans->block_rsv = &root->fs_info->global_block_rsv;
 
@@ -1845,7 +1845,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
 	di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
 				   dir_id, "default", 7, 1);
-	if (!di) {
+	if (IS_ERR_OR_NULL(di)) {
 		btrfs_free_path(path);
 		btrfs_end_transaction(trans, root);
 		printk(KERN_ERR "Umm, you don't have the default dir item, "
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 05d41e569236330cc8ed8e5e0f8b17566080791c..b37d723b9d4a8a137b05256a85788074b5f03c5e 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -784,16 +784,17 @@ struct backref_node *build_backref_tree(struct reloc_control *rc,
 				struct btrfs_extent_ref_v0 *ref0;
 				ref0 = btrfs_item_ptr(eb, path1->slots[0],
 						struct btrfs_extent_ref_v0);
-				root = find_tree_root(rc, eb, ref0);
-				if (!root->ref_cows)
-					cur->cowonly = 1;
 				if (key.objectid == key.offset) {
+					root = find_tree_root(rc, eb, ref0);
 					if (root && !should_ignore_root(root))
 						cur->root = root;
 					else
 						list_add(&cur->list, &useless);
 					break;
 				}
+				if (is_cowonly_root(btrfs_ref_root_v0(eb,
+								      ref0)))
+					cur->cowonly = 1;
 			}
 #else
 		BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index b91ccd972644b48048329806044ebc3c62d1b550..2d958be761c84556b39c60afa39999b0f3fd75d6 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -330,7 +330,6 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 {
 	struct btrfs_path *path;
 	int ret;
-	u32 refs;
 	struct btrfs_root_item *ri;
 	struct extent_buffer *leaf;
 
@@ -344,8 +343,6 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	leaf = path->nodes[0];
 	ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
 
-	refs = btrfs_disk_root_refs(leaf, ri);
-	BUG_ON(refs != 0);
 	ret = btrfs_del_item(trans, root, path);
 out:
 	btrfs_free_path(path);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d34b2dfc9628cde65f6181b5ed4043cf8603541c..f2393b39031812c178fd98cb79eb614f3ba6c65a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -360,6 +360,8 @@ static struct dentry *get_default_root(struct super_block *sb,
 	 */
 	dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
 	di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
+	if (IS_ERR(di))
+		return ERR_CAST(di);
 	if (!di) {
 		/*
 		 * Ok the default dir item isn't there.  This is weird since
@@ -390,8 +392,8 @@ static struct dentry *get_default_root(struct super_block *sb,
 	location.offset = 0;
 
 	inode = btrfs_iget(sb, &location, new_root, &new);
-	if (!inode)
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
 
 	/*
 	 * If we're just mounting the root most subvol put the inode and return