btrfs: root->fs_info cleanup, add fs_info convenience variables

In routines where someptr->fs_info is referenced multiple times, we
introduce a convenience variable.  This makes the code considerably
more readable.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 231 insertions, 193 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 062f67ac1335..d00e4d3c1baf 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -215,6 +215,7 @@ static int check_flags(unsigned int flags)
 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_inode *ip = BTRFS_I(inode);
 	struct btrfs_root *root = ip->root;
 	struct btrfs_trans_handle *trans;
@@ -324,7 +325,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 		ip->flags |= BTRFS_INODE_COMPRESS;
 		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 
-		if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
+		if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
 			comp = "lzo";
 		else
 			comp = "zlib";
@@ -373,7 +374,8 @@ static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 
 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_device *device;
 	struct request_queue *q;
 	struct fstrim_range range;
@@ -436,6 +438,7 @@ static noinline int create_subvol(struct inode *dir,
 				  u64 *async_transid,
 				  struct btrfs_qgroup_inherit *inherit)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 	struct btrfs_trans_handle *trans;
 	struct btrfs_key key;
 	struct btrfs_root_item *root_item;
@@ -458,7 +461,7 @@ static noinline int create_subvol(struct inode *dir,
 	if (!root_item)
 		return -ENOMEM;
 
-	ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
+	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 	if (ret)
 		goto fail_free;
 
@@ -491,7 +494,7 @@ static noinline int create_subvol(struct inode *dir,
 	trans->block_rsv = &block_rsv;
 	trans->bytes_reserved = block_rsv.size;
 
-	ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
+	ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 	if (ret)
 		goto fail;
 
@@ -507,9 +510,8 @@ static noinline int create_subvol(struct inode *dir,
 	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 	btrfs_set_header_owner(leaf, objectid);
 
-	write_extent_buffer_fsid(leaf, root->fs_info->fsid);
-	write_extent_buffer_chunk_tree_uuid(leaf,
-			root->fs_info->chunk_tree_uuid);
+	write_extent_buffer_fsid(leaf, fs_info->fsid);
+	write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 	btrfs_mark_buffer_dirty(leaf);
 
 	inode_item = &root_item->inode;
@@ -517,7 +519,7 @@ static noinline int create_subvol(struct inode *dir,
 	btrfs_set_stack_inode_size(inode_item, 3);
 	btrfs_set_stack_inode_nlink(inode_item, 1);
 	btrfs_set_stack_inode_nbytes(inode_item,
-				     root->fs_info->nodesize);
+				     fs_info->nodesize);
 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 
 	btrfs_set_root_flags(root_item, 0);
@@ -550,13 +552,13 @@ static noinline int create_subvol(struct inode *dir,
 	key.objectid = objectid;
 	key.offset = 0;
 	key.type = BTRFS_ROOT_ITEM_KEY;
-	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 				root_item);
 	if (ret)
 		goto fail;
 
 	key.offset = (u64)-1;
-	new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
+	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 	if (IS_ERR(new_root)) {
 		ret = PTR_ERR(new_root);
 		btrfs_abort_transaction(trans, ret);
@@ -597,12 +599,12 @@ static noinline int create_subvol(struct inode *dir,
 	ret = btrfs_update_inode(trans, root, dir);
 	BUG_ON(ret);
 
-	ret = btrfs_add_root_ref(trans, root->fs_info,
+	ret = btrfs_add_root_ref(trans, fs_info,
 				 objectid, root->root_key.objectid,
 				 btrfs_ino(dir), index, name, namelen);
 	BUG_ON(ret);
 
-	ret = btrfs_uuid_tree_add(trans, root->fs_info, root_item->uuid,
+	ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 				  BTRFS_UUID_KEY_SUBVOL, objectid);
 	if (ret)
 		btrfs_abort_transaction(trans, ret);
@@ -659,6 +661,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 			   u64 *async_transid, bool readonly,
 			   struct btrfs_qgroup_inherit *inherit)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 	struct inode *inode;
 	struct btrfs_pending_snapshot *pending_snapshot;
 	struct btrfs_trans_handle *trans;
@@ -718,19 +721,19 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 		goto fail;
 	}
 
-	spin_lock(&root->fs_info->trans_lock);
+	spin_lock(&fs_info->trans_lock);
 	list_add(&pending_snapshot->list,
 		 &trans->transaction->pending_snapshots);
-	spin_unlock(&root->fs_info->trans_lock);
+	spin_unlock(&fs_info->trans_lock);
 	if (async_transid) {
 		*async_transid = trans->transid;
 		ret = btrfs_commit_transaction_async(trans,
-				     root->fs_info->extent_root, 1);
+				     fs_info->extent_root, 1);
 		if (ret)
 			ret = btrfs_commit_transaction(trans, root);
 	} else {
 		ret = btrfs_commit_transaction(trans,
-					       root->fs_info->extent_root);
+					       fs_info->extent_root);
 	}
 	if (ret)
 		goto fail;
@@ -839,7 +842,8 @@ static noinline int btrfs_mksubvol(struct path *parent,
 				   u64 *async_transid, bool readonly,
 				   struct btrfs_qgroup_inherit *inherit)
 {
-	struct inode *dir  = d_inode(parent->dentry);
+	struct inode *dir = d_inode(parent->dentry);
+	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 	struct dentry *dentry;
 	int error;
 
@@ -866,7 +870,7 @@ static noinline int btrfs_mksubvol(struct path *parent,
 	if (error)
 		goto out_dput;
 
-	down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
+	down_read(&fs_info->subvol_sem);
 
 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 		goto out_up_read;
@@ -881,7 +885,7 @@ static noinline int btrfs_mksubvol(struct path *parent,
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
 out_up_read:
-	up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
+	up_read(&fs_info->subvol_sem);
 out_dput:
 	dput(dentry);
 out_unlock:
@@ -1265,6 +1269,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_to_defrag)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct file_ra_state *ra = NULL;
 	unsigned long last_index;
@@ -1362,8 +1367,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 		if (!(inode->i_sb->s_flags & MS_ACTIVE))
 			break;
 
-		if (btrfs_defrag_cancelled(root->fs_info)) {
-			btrfs_debug(root->fs_info, "defrag_file cancelled");
+		if (btrfs_defrag_cancelled(fs_info)) {
+			btrfs_debug(fs_info, "defrag_file cancelled");
 			ret = -EAGAIN;
 			break;
 		}
@@ -1451,18 +1456,18 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 		 * we have to make sure the IO is actually started and that
 		 * ordered extents get created before we return
 		 */
-		atomic_inc(&root->fs_info->async_submit_draining);
-		while (atomic_read(&root->fs_info->nr_async_submits) ||
-		      atomic_read(&root->fs_info->async_delalloc_pages)) {
-			wait_event(root->fs_info->async_submit_wait,
-			   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
-			    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
+		atomic_inc(&fs_info->async_submit_draining);
+		while (atomic_read(&fs_info->nr_async_submits) ||
+		       atomic_read(&fs_info->async_delalloc_pages)) {
+			wait_event(fs_info->async_submit_wait,
+				   (atomic_read(&fs_info->nr_async_submits) == 0 &&
+				    atomic_read(&fs_info->async_delalloc_pages) == 0));
 		}
-		atomic_dec(&root->fs_info->async_submit_draining);
+		atomic_dec(&fs_info->async_submit_draining);
 	}
 
 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
-		btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
+		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
 	}
 
 	ret = defrag_count;
@@ -1482,10 +1487,12 @@ out_ra:
 static noinline int btrfs_ioctl_resize(struct file *file,
 					void __user *arg)
 {
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	u64 new_size;
 	u64 old_size;
 	u64 devid = 1;
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_vol_args *vol_args;
 	struct btrfs_trans_handle *trans;
 	struct btrfs_device *device = NULL;
@@ -1502,13 +1509,12 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 	if (ret)
 		return ret;
 
-	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
-			1)) {
+	if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
 		mnt_drop_write_file(file);
 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
 	}
 
-	mutex_lock(&root->fs_info->volume_mutex);
+	mutex_lock(&fs_info->volume_mutex);
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args)) {
 		ret = PTR_ERR(vol_args);
@@ -1530,19 +1536,19 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 			ret = -EINVAL;
 			goto out_free;
 		}
-		btrfs_info(root->fs_info, "resizing devid %llu", devid);
+		btrfs_info(fs_info, "resizing devid %llu", devid);
 	}
 
-	device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
+	device = btrfs_find_device(fs_info, devid, NULL, NULL);
 	if (!device) {
-		btrfs_info(root->fs_info, "resizer unable to find device %llu",
-		       devid);
+		btrfs_info(fs_info, "resizer unable to find device %llu",
+			   devid);
 		ret = -ENODEV;
 		goto out_free;
 	}
 
 	if (!device->writeable) {
-		btrfs_info(root->fs_info,
+		btrfs_info(fs_info,
 			   "resizer unable to apply on readonly device %llu",
 		       devid);
 		ret = -EPERM;
@@ -1596,11 +1602,11 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 		goto out_free;
 	}
 
-	new_size = div_u64(new_size, root->fs_info->sectorsize);
-	new_size *= root->fs_info->sectorsize;
+	new_size = div_u64(new_size, fs_info->sectorsize);
+	new_size *= fs_info->sectorsize;
 
-	btrfs_info_in_rcu(root->fs_info, "new size for %s is %llu",
-		      rcu_str_deref(device->name), new_size);
+	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
+			  rcu_str_deref(device->name), new_size);
 
 	if (new_size > old_size) {
 		trans = btrfs_start_transaction(root, 0);
@@ -1617,8 +1623,8 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 out_free:
 	kfree(vol_args);
 out:
-	mutex_unlock(&root->fs_info->volume_mutex);
-	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+	mutex_unlock(&fs_info->volume_mutex);
+	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
 	mnt_drop_write_file(file);
 	return ret;
 }
@@ -1771,6 +1777,7 @@ static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
 						void __user *arg)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	int ret = 0;
 	u64 flags = 0;
@@ -1778,10 +1785,10 @@ static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
 		return -EINVAL;
 
-	down_read(&root->fs_info->subvol_sem);
+	down_read(&fs_info->subvol_sem);
 	if (btrfs_root_readonly(root))
 		flags |= BTRFS_SUBVOL_RDONLY;
-	up_read(&root->fs_info->subvol_sem);
+	up_read(&fs_info->subvol_sem);
 
 	if (copy_to_user(arg, &flags, sizeof(flags)))
 		ret = -EFAULT;
@@ -1793,6 +1800,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 					      void __user *arg)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
 	u64 root_flags;
@@ -1826,7 +1834,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 		goto out_drop_write;
 	}
 
-	down_write(&root->fs_info->subvol_sem);
+	down_write(&fs_info->subvol_sem);
 
 	/* nothing to do */
 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
@@ -1848,9 +1856,9 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 			spin_unlock(&root->root_item_lock);
 		} else {
 			spin_unlock(&root->root_item_lock);
-			btrfs_warn(root->fs_info,
-			"Attempt to set subvolume %llu read-write during send",
-					root->root_key.objectid);
+			btrfs_warn(fs_info,
+				   "Attempt to set subvolume %llu read-write during send",
+				   root->root_key.objectid);
 			ret = -EPERM;
 			goto out_drop_sem;
 		}
@@ -1862,7 +1870,7 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 		goto out_reset;
 	}
 
-	ret = btrfs_update_root(trans, root->fs_info->tree_root,
+	ret = btrfs_update_root(trans, fs_info->tree_root,
 				&root->root_key, &root->root_item);
 
 	btrfs_commit_transaction(trans, root);
@@ -1870,7 +1878,7 @@ out_reset:
 	if (ret)
 		btrfs_set_root_flags(&root->root_item, root_flags);
 out_drop_sem:
-	up_write(&root->fs_info->subvol_sem);
+	up_write(&fs_info->subvol_sem);
 out_drop_write:
 	mnt_drop_write_file(file);
 out:
@@ -1882,6 +1890,7 @@ out:
  */
 static noinline int may_destroy_subvol(struct btrfs_root *root)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_path *path;
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
@@ -1893,14 +1902,14 @@ static noinline int may_destroy_subvol(struct btrfs_root *root)
 		return -ENOMEM;
 
 	/* Make sure this root isn't set as the default subvol */
-	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
-	di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
+	dir_id = btrfs_super_root_dir(fs_info->super_copy);
+	di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
 				   dir_id, "default", 7, 0);
 	if (di && !IS_ERR(di)) {
 		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
 		if (key.objectid == root->root_key.objectid) {
 			ret = -EPERM;
-			btrfs_err(root->fs_info,
+			btrfs_err(fs_info,
 				  "deleting default subvolume %llu is not allowed",
 				  key.objectid);
 			goto out;
@@ -1912,8 +1921,7 @@ static noinline int may_destroy_subvol(struct btrfs_root *root)
 	key.type = BTRFS_ROOT_REF_KEY;
 	key.offset = (u64)-1;
 
-	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
-				&key, path, 0, 0);
+	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
 	if (ret < 0)
 		goto out;
 	BUG_ON(ret == 0);
@@ -2084,10 +2092,10 @@ static noinline int search_ioctl(struct inode *inode,
 				 size_t *buf_size,
 				 char __user *ubuf)
 {
+	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root;
 	struct btrfs_key key;
 	struct btrfs_path *path;
-	struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
 	int ret;
 	int num_found = 0;
 	unsigned long sk_offset = 0;
@@ -2350,6 +2358,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 					     void __user *arg)
 {
 	struct dentry *parent = file->f_path.dentry;
+	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
 	struct dentry *dentry;
 	struct inode *dir = d_inode(parent);
 	struct inode *inode;
@@ -2415,7 +2424,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		 * rmdir(2).
 		 */
 		err = -EPERM;
-		if (!btrfs_test_opt(root->fs_info, USER_SUBVOL_RM_ALLOWED))
+		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
 			goto out_dput;
 
 		/*
@@ -2459,14 +2468,14 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		spin_unlock(&dest->root_item_lock);
 	} else {
 		spin_unlock(&dest->root_item_lock);
-		btrfs_warn(root->fs_info,
-			"Attempt to delete subvolume %llu during send",
-			dest->root_key.objectid);
+		btrfs_warn(fs_info,
+			   "Attempt to delete subvolume %llu during send",
+			   dest->root_key.objectid);
 		err = -EPERM;
 		goto out_unlock_inode;
 	}
 
-	down_write(&root->fs_info->subvol_sem);
+	down_write(&fs_info->subvol_sem);
 
 	err = may_destroy_subvol(dest);
 	if (err)
@@ -2511,7 +2520,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 
 	if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
 		ret = btrfs_insert_orphan_item(trans,
-					root->fs_info->tree_root,
+					fs_info->tree_root,
 					dest->root_key.objectid);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
@@ -2520,7 +2529,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		}
 	}
 
-	ret = btrfs_uuid_tree_rem(trans, root->fs_info, dest->root_item.uuid,
+	ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
 				  BTRFS_UUID_KEY_SUBVOL,
 				  dest->root_key.objectid);
 	if (ret && ret != -ENOENT) {
@@ -2529,7 +2538,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		goto out_end_trans;
 	}
 	if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
-		ret = btrfs_uuid_tree_rem(trans, root->fs_info,
+		ret = btrfs_uuid_tree_rem(trans, fs_info,
 					  dest->root_item.received_uuid,
 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
 					  dest->root_key.objectid);
@@ -2550,7 +2559,7 @@ out_end_trans:
 out_release:
 	btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 out_up_write:
-	up_write(&root->fs_info->subvol_sem);
+	up_write(&fs_info->subvol_sem);
 	if (err) {
 		spin_lock(&dest->root_item_lock);
 		root_flags = btrfs_root_flags(&dest->root_item);
@@ -2654,18 +2663,17 @@ out:
 
 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ioctl_vol_args *vol_args;
 	int ret;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
-			1)) {
+	if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1))
 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
-	}
 
-	mutex_lock(&root->fs_info->volume_mutex);
+	mutex_lock(&fs_info->volume_mutex);
 	vol_args = memdup_user(arg, sizeof(*vol_args));
 	if (IS_ERR(vol_args)) {
 		ret = PTR_ERR(vol_args);
@@ -2676,18 +2684,20 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 	ret = btrfs_init_new_device(root->fs_info, vol_args->name);
 
 	if (!ret)
-		btrfs_info(root->fs_info, "disk added %s",vol_args->name);
+		btrfs_info(fs_info, "disk added %s", vol_args->name);
 
 	kfree(vol_args);
 out:
-	mutex_unlock(&root->fs_info->volume_mutex);
-	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+	mutex_unlock(&fs_info->volume_mutex);
+	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
 	return ret;
 }
 
 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_vol_args_v2 *vol_args;
 	int ret;
 
@@ -2708,28 +2718,27 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
 	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
 		return -EOPNOTSUPP;
 
-	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
-			1)) {
+	if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
 		goto out;
 	}
 
-	mutex_lock(&root->fs_info->volume_mutex);
+	mutex_lock(&fs_info->volume_mutex);
 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
 		ret = btrfs_rm_device(root, NULL, vol_args->devid);
 	} else {
 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
 		ret = btrfs_rm_device(root, vol_args->name, 0);
 	}
-	mutex_unlock(&root->fs_info->volume_mutex);
-	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+	mutex_unlock(&fs_info->volume_mutex);
+	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
 
 	if (!ret) {
 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
-			btrfs_info(root->fs_info, "device deleted: id %llu",
+			btrfs_info(fs_info, "device deleted: id %llu",
 					vol_args->devid);
 		else
-			btrfs_info(root->fs_info, "device deleted: %s",
+			btrfs_info(fs_info, "device deleted: %s",
 					vol_args->name);
 	}
 out:
@@ -2741,7 +2750,9 @@ err_drop:
 
 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_vol_args *vol_args;
 	int ret;
 
@@ -2752,8 +2763,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 	if (ret)
 		return ret;
 
-	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
-			1)) {
+	if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
 		goto out_drop_write;
 	}
@@ -2765,15 +2775,15 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
 	}
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
-	mutex_lock(&root->fs_info->volume_mutex);
+	mutex_lock(&fs_info->volume_mutex);
 	ret = btrfs_rm_device(root, vol_args->name, 0);
-	mutex_unlock(&root->fs_info->volume_mutex);
+	mutex_unlock(&fs_info->volume_mutex);
 
 	if (!ret)
-		btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
+		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
 	kfree(vol_args);
 out:
-	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
 out_drop_write:
 	mnt_drop_write_file(file);
 
@@ -2782,9 +2792,10 @@ out_drop_write:
 
 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ioctl_fs_info_args *fi_args;
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	int ret = 0;
 
 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
@@ -2793,7 +2804,7 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
 
 	mutex_lock(&fs_devices->device_list_mutex);
 	fi_args->num_devices = fs_devices->num_devices;
-	memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
+	memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
 
 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		if (device->devid > fi_args->max_id)
@@ -2801,9 +2812,9 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
 	}
 	mutex_unlock(&fs_devices->device_list_mutex);
 
-	fi_args->nodesize = root->fs_info->super_copy->nodesize;
-	fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
-	fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
+	fi_args->nodesize = fs_info->super_copy->nodesize;
+	fi_args->sectorsize = fs_info->super_copy->sectorsize;
+	fi_args->clone_alignment = fs_info->super_copy->sectorsize;
 
 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
 		ret = -EFAULT;
@@ -2814,9 +2825,10 @@ static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
 
 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ioctl_dev_info_args *di_args;
 	struct btrfs_device *dev;
-	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	int ret = 0;
 	char *s_uuid = NULL;
 
@@ -2828,7 +2840,7 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
 		s_uuid = di_args->uuid;
 
 	mutex_lock(&fs_devices->device_list_mutex);
-	dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
+	dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
 
 	if (!dev) {
 		ret = -ENODEV;
@@ -3403,9 +3415,10 @@ static int clone_copy_inline_extent(struct inode *src,
 				    const u64 size,
 				    char *inline_data)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
 	struct btrfs_root *root = BTRFS_I(dst)->root;
 	const u64 aligned_end = ALIGN(new_key->offset + datal,
-				      root->fs_info->sectorsize);
+				      fs_info->sectorsize);
 	int ret;
 	struct btrfs_key key;
 
@@ -3526,6 +3539,7 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 		       const u64 off, const u64 olen, const u64 olen_aligned,
 		       const u64 destoff, int no_time_update)
 {
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_path *path = NULL;
 	struct extent_buffer *leaf;
@@ -3539,10 +3553,9 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 	u64 last_dest_end = destoff;
 
 	ret = -ENOMEM;
-	buf = kmalloc(root->fs_info->nodesize,
-		      GFP_KERNEL | __GFP_NOWARN);
+	buf = kmalloc(fs_info->nodesize, GFP_KERNEL | __GFP_NOWARN);
 	if (!buf) {
-		buf = vmalloc(root->fs_info->nodesize);
+		buf = vmalloc(fs_info->nodesize);
 		if (!buf)
 			return ret;
 	}
@@ -3800,7 +3813,7 @@ process_slot:
 			btrfs_release_path(path);
 
 			last_dest_end = ALIGN(new_key.offset + datal,
-					      root->fs_info->sectorsize);
+					      fs_info->sectorsize);
 			ret = clone_finish_inode_update(trans, inode,
 							last_dest_end,
 							destoff, olen,
@@ -3861,10 +3874,11 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
 {
 	struct inode *inode = file_inode(file);
 	struct inode *src = file_inode(file_src);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	int ret;
 	u64 len = olen;
-	u64 bs = root->fs_info->sb->s_blocksize;
+	u64 bs = fs_info->sb->s_blocksize;
 	int same_inode = src == inode;
 
 	/*
@@ -4005,6 +4019,7 @@ int btrfs_clone_file_range(struct file *src_file, loff_t off,
 static long btrfs_ioctl_trans_start(struct file *file)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
 	int ret;
@@ -4025,7 +4040,7 @@ static long btrfs_ioctl_trans_start(struct file *file)
 	if (ret)
 		goto out;
 
-	atomic_inc(&root->fs_info->open_ioctl_trans);
+	atomic_inc(&fs_info->open_ioctl_trans);
 
 	ret = -ENOMEM;
 	trans = btrfs_start_ioctl_transaction(root);
@@ -4036,7 +4051,7 @@ static long btrfs_ioctl_trans_start(struct file *file)
 	return 0;
 
 out_drop:
-	atomic_dec(&root->fs_info->open_ioctl_trans);
+	atomic_dec(&fs_info->open_ioctl_trans);
 	mnt_drop_write_file(file);
 out:
 	return ret;
@@ -4045,6 +4060,7 @@ out:
 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_root *new_root;
 	struct btrfs_dir_item *di;
@@ -4075,7 +4091,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	location.type = BTRFS_ROOT_ITEM_KEY;
 	location.offset = (u64)-1;
 
-	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
+	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 	if (IS_ERR(new_root)) {
 		ret = PTR_ERR(new_root);
 		goto out;
@@ -4095,13 +4111,13 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 		goto out;
 	}
 
-	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 = btrfs_super_root_dir(fs_info->super_copy);
+	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
 				   dir_id, "default", 7, 1);
 	if (IS_ERR_OR_NULL(di)) {
 		btrfs_free_path(path);
 		btrfs_end_transaction(trans, root);
-		btrfs_err(new_root->fs_info,
+		btrfs_err(fs_info,
 			  "Umm, you don't have the default diritem, this isn't going to work");
 		ret = -ENOENT;
 		goto out;
@@ -4112,7 +4128,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	btrfs_free_path(path);
 
-	btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
+	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
 	btrfs_end_transaction(trans, root);
 out:
 	mnt_drop_write_file(file);
@@ -4137,6 +4153,7 @@ void btrfs_get_block_group_info(struct list_head *groups_list,
 
 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ioctl_space_args space_args;
 	struct btrfs_ioctl_space_info space;
 	struct btrfs_ioctl_space_info *dest;
@@ -4163,7 +4180,7 @@ static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 
 		info = NULL;
 		rcu_read_lock();
-		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
+		list_for_each_entry_rcu(tmp, &fs_info->space_info,
 					list) {
 			if (tmp->flags == types[i]) {
 				info = tmp;
@@ -4219,7 +4236,7 @@ static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 
 		info = NULL;
 		rcu_read_lock();
-		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
+		list_for_each_entry_rcu(tmp, &fs_info->space_info,
 					list) {
 			if (tmp->flags == types[i]) {
 				info = tmp;
@@ -4250,7 +4267,7 @@ static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 	 * Add global block reserve
 	 */
 	if (slot_count) {
-		struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
+		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
 
 		spin_lock(&block_rsv->lock);
 		space.total_bytes = block_rsv->size;
@@ -4345,7 +4362,7 @@ static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
 
 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
 	struct btrfs_ioctl_scrub_args *sa;
 	int ret;
 
@@ -4362,7 +4379,7 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
 			goto out;
 	}
 
-	ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
+	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
 			      0);
 
@@ -4432,6 +4449,7 @@ static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
 
 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_ioctl_dev_replace_args *p;
 	int ret;
 
@@ -4444,27 +4462,25 @@ static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
 
 	switch (p->cmd) {
 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
-		if (root->fs_info->sb->s_flags & MS_RDONLY) {
+		if (fs_info->sb->s_flags & MS_RDONLY) {
 			ret = -EROFS;
 			goto out;
 		}
 		if (atomic_xchg(
-			&root->fs_info->mutually_exclusive_operation_running,
-			1)) {
+			&fs_info->mutually_exclusive_operation_running, 1)) {
 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
 		} else {
 			ret = btrfs_dev_replace_by_ioctl(root, p);
 			atomic_set(
-			 &root->fs_info->mutually_exclusive_operation_running,
-			 0);
+			 &fs_info->mutually_exclusive_operation_running, 0);
 		}
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
-		btrfs_dev_replace_status(root->fs_info, p);
+		btrfs_dev_replace_status(fs_info, p);
 		ret = 0;
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
-		ret = btrfs_dev_replace_cancel(root->fs_info, p);
+		ret = btrfs_dev_replace_cancel(fs_info, p);
 		break;
 	default:
 		ret = -EINVAL;
@@ -4785,14 +4801,16 @@ out:
 
 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
+
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
 	switch (cmd) {
 	case BTRFS_BALANCE_CTL_PAUSE:
-		return btrfs_pause_balance(root->fs_info);
+		return btrfs_pause_balance(fs_info);
 	case BTRFS_BALANCE_CTL_CANCEL:
-		return btrfs_cancel_balance(root->fs_info);
+		return btrfs_cancel_balance(fs_info);
 	}
 
 	return -EINVAL;
@@ -4833,7 +4851,8 @@ out:
 
 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_ioctl_quota_ctl_args *sa;
 	struct btrfs_trans_handle *trans = NULL;
 	int ret;
@@ -4852,8 +4871,8 @@ static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
 		goto drop_write;
 	}
 
-	down_write(&root->fs_info->subvol_sem);
-	trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
+	down_write(&fs_info->subvol_sem);
+	trans = btrfs_start_transaction(fs_info->tree_root, 2);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
 		goto out;
@@ -4861,22 +4880,22 @@ static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
 
 	switch (sa->cmd) {
 	case BTRFS_QUOTA_CTL_ENABLE:
-		ret = btrfs_quota_enable(trans, root->fs_info);
+		ret = btrfs_quota_enable(trans, fs_info);
 		break;
 	case BTRFS_QUOTA_CTL_DISABLE:
-		ret = btrfs_quota_disable(trans, root->fs_info);
+		ret = btrfs_quota_disable(trans, fs_info);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
 
-	err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
+	err = btrfs_commit_transaction(trans, fs_info->tree_root);
 	if (err && !ret)
 		ret = err;
 out:
 	kfree(sa);
-	up_write(&root->fs_info->subvol_sem);
+	up_write(&fs_info->subvol_sem);
 drop_write:
 	mnt_drop_write_file(file);
 	return ret;
@@ -4884,7 +4903,9 @@ drop_write:
 
 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_qgroup_assign_args *sa;
 	struct btrfs_trans_handle *trans;
 	int ret;
@@ -4911,18 +4932,18 @@ static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
 
 	/* FIXME: check if the IDs really exist */
 	if (sa->assign) {
-		ret = btrfs_add_qgroup_relation(trans, root->fs_info,
+		ret = btrfs_add_qgroup_relation(trans, fs_info,
 						sa->src, sa->dst);
 	} else {
-		ret = btrfs_del_qgroup_relation(trans, root->fs_info,
+		ret = btrfs_del_qgroup_relation(trans, fs_info,
 						sa->src, sa->dst);
 	}
 
 	/* update qgroup status and info */
-	err = btrfs_run_qgroups(trans, root->fs_info);
+	err = btrfs_run_qgroups(trans, fs_info);
 	if (err < 0)
-		btrfs_handle_fs_error(root->fs_info, err,
-			    "failed to update qgroup status and info");
+		btrfs_handle_fs_error(fs_info, err,
+				      "failed to update qgroup status and info");
 	err = btrfs_end_transaction(trans, root);
 	if (err && !ret)
 		ret = err;
@@ -4936,7 +4957,9 @@ drop_write:
 
 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_qgroup_create_args *sa;
 	struct btrfs_trans_handle *trans;
 	int ret;
@@ -4968,9 +4991,9 @@ static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
 
 	/* FIXME: check if the IDs really exist */
 	if (sa->create) {
-		ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid);
+		ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
 	} else {
-		ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
+		ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
 	}
 
 	err = btrfs_end_transaction(trans, root);
@@ -4986,7 +5009,9 @@ drop_write:
 
 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ioctl_qgroup_limit_args *sa;
 	struct btrfs_trans_handle *trans;
 	int ret;
@@ -5019,7 +5044,7 @@ static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
 	}
 
 	/* FIXME: check if the IDs really exist */
-	ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
+	ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
 
 	err = btrfs_end_transaction(trans, root);
 	if (err && !ret)
@@ -5034,7 +5059,8 @@ drop_write:
 
 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_ioctl_quota_rescan_args *qsa;
 	int ret;
 
@@ -5056,7 +5082,7 @@ static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
 		goto out;
 	}
 
-	ret = btrfs_qgroup_rescan(root->fs_info);
+	ret = btrfs_qgroup_rescan(fs_info);
 
 out:
 	kfree(qsa);
@@ -5067,7 +5093,8 @@ drop_write:
 
 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_ioctl_quota_rescan_args *qsa;
 	int ret = 0;
 
@@ -5078,9 +5105,9 @@ static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
 	if (!qsa)
 		return -ENOMEM;
 
-	if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
+	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
 		qsa->flags = 1;
-		qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
+		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
 	}
 
 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
@@ -5092,18 +5119,20 @@ static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
 
 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	return btrfs_qgroup_wait_for_completion(root->fs_info, true);
+	return btrfs_qgroup_wait_for_completion(fs_info, true);
 }
 
 static long _btrfs_ioctl_set_received_subvol(struct file *file,
 					    struct btrfs_ioctl_received_subvol_args *sa)
 {
 	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_root_item *root_item = &root->root_item;
 	struct btrfs_trans_handle *trans;
@@ -5118,7 +5147,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	if (ret < 0)
 		return ret;
 
-	down_write(&root->fs_info->subvol_sem);
+	down_write(&fs_info->subvol_sem);
 
 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
 		ret = -EINVAL;
@@ -5149,8 +5178,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 				       BTRFS_UUID_SIZE);
 	if (received_uuid_changed &&
 	    !btrfs_is_empty_uuid(root_item->received_uuid))
-		btrfs_uuid_tree_rem(trans, root->fs_info,
-				    root_item->received_uuid,
+		btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
 				    BTRFS_UUID_KEY_RECEIVED_SUBVOL,
 				    root->root_key.objectid);
 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
@@ -5161,14 +5189,14 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
 
-	ret = btrfs_update_root(trans, root->fs_info->tree_root,
+	ret = btrfs_update_root(trans, fs_info->tree_root,
 				&root->root_key, &root->root_item);
 	if (ret < 0) {
 		btrfs_end_transaction(trans, root);
 		goto out;
 	}
 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
-		ret = btrfs_uuid_tree_add(trans, root->fs_info, sa->uuid,
+		ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
 					  root->root_key.objectid);
 		if (ret < 0 && ret != -EEXIST) {
@@ -5183,7 +5211,7 @@ static long _btrfs_ioctl_set_received_subvol(struct file *file,
 	}
 
 out:
-	up_write(&root->fs_info->subvol_sem);
+	up_write(&fs_info->subvol_sem);
 	mnt_drop_write_file(file);
 	return ret;
 }
@@ -5265,20 +5293,22 @@ out:
 
 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	size_t len;
 	int ret;
 	char label[BTRFS_LABEL_SIZE];
 
-	spin_lock(&root->fs_info->super_lock);
-	memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
-	spin_unlock(&root->fs_info->super_lock);
+	spin_lock(&fs_info->super_lock);
+	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
+	spin_unlock(&fs_info->super_lock);
 
 	len = strnlen(label, BTRFS_LABEL_SIZE);
 
 	if (len == BTRFS_LABEL_SIZE) {
-		btrfs_warn(root->fs_info,
-			"label is too long, return the first %zu bytes", --len);
+		btrfs_warn(fs_info,
+			   "label is too long, return the first %zu bytes",
+			   --len);
 	}
 
 	ret = copy_to_user(arg, label, len);
@@ -5288,8 +5318,10 @@ static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
 
 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
-	struct btrfs_super_block *super_block = root->fs_info->super_copy;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_super_block *super_block = fs_info->super_copy;
 	struct btrfs_trans_handle *trans;
 	char label[BTRFS_LABEL_SIZE];
 	int ret;
@@ -5301,7 +5333,7 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
 		return -EFAULT;
 
 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
-		btrfs_err(root->fs_info,
+		btrfs_err(fs_info,
 			  "unable to set label with more than %d bytes",
 			  BTRFS_LABEL_SIZE - 1);
 		return -EINVAL;
@@ -5317,9 +5349,9 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
 		goto out_unlock;
 	}
 
-	spin_lock(&root->fs_info->super_lock);
+	spin_lock(&fs_info->super_lock);
 	strcpy(super_block->label, label);
-	spin_unlock(&root->fs_info->super_lock);
+	spin_unlock(&fs_info->super_lock);
 	ret = btrfs_commit_transaction(trans, root);
 
 out_unlock:
@@ -5348,8 +5380,9 @@ int btrfs_ioctl_get_supported_features(void __user *arg)
 
 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
-	struct btrfs_super_block *super_block = root->fs_info->super_copy;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_super_block *super_block = fs_info->super_copy;
 	struct btrfs_ioctl_feature_flags features;
 
 	features.compat_flags = btrfs_super_compat_flags(super_block);
@@ -5367,6 +5400,7 @@ static int check_feature_bits(struct btrfs_root *root,
 			      u64 change_mask, u64 flags, u64 supported_flags,
 			      u64 safe_set, u64 safe_clear)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	const char *type = btrfs_feature_set_names[set];
 	char *names;
 	u64 disallowed, unsupported;
@@ -5377,14 +5411,14 @@ static int check_feature_bits(struct btrfs_root *root,
 	if (unsupported) {
 		names = btrfs_printable_features(set, unsupported);
 		if (names) {
-			btrfs_warn(root->fs_info,
-			   "this kernel does not support the %s feature bit%s",
-			   names, strchr(names, ',') ? "s" : "");
+			btrfs_warn(fs_info,
+				   "this kernel does not support the %s feature bit%s",
+				   names, strchr(names, ',') ? "s" : "");
 			kfree(names);
 		} else
-			btrfs_warn(root->fs_info,
-			   "this kernel does not support %s bits 0x%llx",
-			   type, unsupported);
+			btrfs_warn(fs_info,
+				   "this kernel does not support %s bits 0x%llx",
+				   type, unsupported);
 		return -EOPNOTSUPP;
 	}
 
@@ -5392,14 +5426,14 @@ static int check_feature_bits(struct btrfs_root *root,
 	if (disallowed) {
 		names = btrfs_printable_features(set, disallowed);
 		if (names) {
-			btrfs_warn(root->fs_info,
-			   "can't set the %s feature bit%s while mounted",
-			   names, strchr(names, ',') ? "s" : "");
+			btrfs_warn(fs_info,
+				   "can't set the %s feature bit%s while mounted",
+				   names, strchr(names, ',') ? "s" : "");
 			kfree(names);
 		} else
-			btrfs_warn(root->fs_info,
-			   "can't set %s bits 0x%llx while mounted",
-			   type, disallowed);
+			btrfs_warn(fs_info,
+				   "can't set %s bits 0x%llx while mounted",
+				   type, disallowed);
 		return -EPERM;
 	}
 
@@ -5407,14 +5441,14 @@ static int check_feature_bits(struct btrfs_root *root,
 	if (disallowed) {
 		names = btrfs_printable_features(set, disallowed);
 		if (names) {
-			btrfs_warn(root->fs_info,
-			   "can't clear the %s feature bit%s while mounted",
-			   names, strchr(names, ',') ? "s" : "");
+			btrfs_warn(fs_info,
+				   "can't clear the %s feature bit%s while mounted",
+				   names, strchr(names, ',') ? "s" : "");
 			kfree(names);
 		} else
-			btrfs_warn(root->fs_info,
-			   "can't clear %s bits 0x%llx while mounted",
-			   type, disallowed);
+			btrfs_warn(fs_info,
+				   "can't clear %s bits 0x%llx while mounted",
+				   type, disallowed);
 		return -EPERM;
 	}
 
@@ -5429,8 +5463,10 @@ check_feature_bits(root, FEAT_##mask_base, change_mask, flags,	\
 
 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
-	struct btrfs_super_block *super_block = root->fs_info->super_copy;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_super_block *super_block = fs_info->super_copy;
 	struct btrfs_ioctl_feature_flags flags[2];
 	struct btrfs_trans_handle *trans;
 	u64 newflags;
@@ -5472,7 +5508,7 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 		goto out_drop_write;
 	}
 
-	spin_lock(&root->fs_info->super_lock);
+	spin_lock(&fs_info->super_lock);
 	newflags = btrfs_super_compat_flags(super_block);
 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
@@ -5487,7 +5523,7 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
 	btrfs_set_super_incompat_flags(super_block, newflags);
-	spin_unlock(&root->fs_info->super_lock);
+	spin_unlock(&fs_info->super_lock);
 
 	ret = btrfs_commit_transaction(trans, root);
 out_drop_write:
@@ -5499,7 +5535,9 @@ out_drop_write:
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
-	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
+	struct inode *inode = file_inode(file);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	void __user *argp = (void __user *)arg;
 
 	switch (cmd) {
@@ -5564,16 +5602,16 @@ long btrfs_ioctl(struct file *file, unsigned int
 	case BTRFS_IOC_SYNC: {
 		int ret;
 
-		ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
+		ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
 		if (ret)
 			return ret;
-		ret = btrfs_sync_fs(file_inode(file)->i_sb, 1);
+		ret = btrfs_sync_fs(inode->i_sb, 1);
 		/*
 		 * The transaction thread may want to do more work,
 		 * namely it pokes the cleaner kthread that will start
 		 * processing uncleaned subvols.
 		 */
-		wake_up_process(root->fs_info->transaction_kthread);
+		wake_up_process(fs_info->transaction_kthread);
 		return ret;
 	}
 	case BTRFS_IOC_START_SYNC: