Beispiel #1
0
static bool ubifs_crypt_empty_dir(struct inode *inode)
{
	return ubifs_check_dir_empty(inode) == 0;
}
Beispiel #2
0
static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
		      struct dentry *dentry)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct inode *inode = d_inode(old_dentry);
	struct ubifs_inode *ui = ubifs_inode(inode);
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
	struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
	struct fscrypt_name nm;

	/*
	 * Budget request settings: new direntry, changing the target inode,
	 * changing the parent inode.
	 */

	dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
		dentry, inode->i_ino,
		inode->i_nlink, dir->i_ino);
	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));

	if (ubifs_crypt_is_encrypted(dir) &&
	    !fscrypt_has_permitted_context(dir, inode))
		return -EPERM;

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		return err;

	err = dbg_check_synced_i_size(c, inode);
	if (err)
		goto out_fname;

	err = ubifs_budget_space(c, &req);
	if (err)
		goto out_fname;

	lock_2_inodes(dir, inode);

	/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
	if (inode->i_nlink == 0)
		ubifs_delete_orphan(c, inode->i_ino);

	inc_nlink(inode);
	ihold(inode);
	inode->i_ctime = current_time(inode);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

	ubifs_release_budget(c, &req);
	d_instantiate(dentry, inode);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	drop_nlink(inode);
	if (inode->i_nlink == 0)
		ubifs_add_orphan(c, inode->i_ino);
	unlock_2_inodes(dir, inode);
	ubifs_release_budget(c, &req);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
	return err;
}

static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct inode *inode = d_inode(dentry);
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	int err, sz_change, budgeted = 1;
	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
	unsigned int saved_nlink = inode->i_nlink;
	struct fscrypt_name nm;

	/*
	 * Budget request settings: deletion direntry, deletion inode (+1 for
	 * @dirtied_ino), changing the parent directory inode. If budgeting
	 * fails, go ahead anyway because we have extra space reserved for
	 * deletions.
	 */

	dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
		dentry, inode->i_ino,
		inode->i_nlink, dir->i_ino);

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
	if (err)
		return err;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));
	err = dbg_check_synced_i_size(c, inode);
	if (err)
		goto out_fname;

	err = ubifs_budget_space(c, &req);
	if (err) {
		if (err != -ENOSPC)
			goto out_fname;
		budgeted = 0;
	}

	lock_2_inodes(dir, inode);
	inode->i_ctime = current_time(dir);
	drop_nlink(inode);
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

	if (budgeted)
		ubifs_release_budget(c, &req);
	else {
		/* We've deleted something - clean the "no space" flags */
		c->bi.nospace = c->bi.nospace_rp = 0;
		smp_wmb();
	}
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	set_nlink(inode, saved_nlink);
	unlock_2_inodes(dir, inode);
	if (budgeted)
		ubifs_release_budget(c, &req);
out_fname:
	fscrypt_free_filename(&nm);
	return err;
}

/**
 * check_dir_empty - check if a directory is empty or not.
 * @dir: VFS inode object of the directory to check
 *
 * This function checks if directory @dir is empty. Returns zero if the
 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
 * in case of of errors.
 */
int ubifs_check_dir_empty(struct inode *dir)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct fscrypt_name nm = { 0 };
	struct ubifs_dent_node *dent;
	union ubifs_key key;
	int err;

	lowest_dent_key(c, &key, dir->i_ino);
	dent = ubifs_tnc_next_ent(c, &key, &nm);
	if (IS_ERR(dent)) {
		err = PTR_ERR(dent);
		if (err == -ENOENT)
			err = 0;
	} else {
		kfree(dent);
		err = -ENOTEMPTY;
	}
	return err;
}

static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct inode *inode = d_inode(dentry);
	int err, sz_change, budgeted = 1;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
	struct fscrypt_name nm;

	/*
	 * Budget request settings: deletion direntry, deletion inode and
	 * changing the parent inode. If budgeting fails, go ahead anyway
	 * because we have extra space reserved for deletions.
	 */

	dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
		inode->i_ino, dir->i_ino);
	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));
	err = ubifs_check_dir_empty(d_inode(dentry));
	if (err)
		return err;

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
	if (err)
		return err;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	err = ubifs_budget_space(c, &req);
	if (err) {
		if (err != -ENOSPC)
			goto out_fname;
		budgeted = 0;
	}

	lock_2_inodes(dir, inode);
	inode->i_ctime = current_time(dir);
	clear_nlink(inode);
	drop_nlink(dir);
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

	if (budgeted)
		ubifs_release_budget(c, &req);
	else {
		/* We've deleted something - clean the "no space" flags */
		c->bi.nospace = c->bi.nospace_rp = 0;
		smp_wmb();
	}
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	inc_nlink(dir);
	set_nlink(inode, 2);
	unlock_2_inodes(dir, inode);
	if (budgeted)
		ubifs_release_budget(c, &req);
out_fname:
	fscrypt_free_filename(&nm);
	return err;
}

static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct inode *inode;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	int err, sz_change;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
	struct fscrypt_name nm;

	/*
	 * Budget request settings: new inode, new direntry and changing parent
	 * directory inode.
	 */

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

	err = ubifs_budget_space(c, &req);
	if (err)
		return err;

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fname;
	}

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&dir_ui->ui_mutex);
	insert_inode_hash(inode);
	inc_nlink(inode);
	inc_nlink(dir);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
	if (err) {
		ubifs_err(c, "cannot create directory, error %d", err);
		goto out_cancel;
	}
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	d_instantiate(dentry, inode);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	drop_nlink(dir);
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
		       umode_t mode, dev_t rdev)
{
	struct inode *inode;
	struct ubifs_inode *ui;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	union ubifs_dev_desc *dev = NULL;
	int sz_change;
	int err, devlen = 0;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.dirtied_ino = 1 };
	struct fscrypt_name nm;

	/*
	 * Budget request settings: new inode, new direntry and changing parent
	 * directory inode.
	 */

	dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);

	if (S_ISBLK(mode) || S_ISCHR(mode)) {
		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
		if (!dev)
			return -ENOMEM;
		devlen = ubifs_encode_dev(dev, rdev);
	}

	req.new_ino_d = ALIGN(devlen, 8);
	err = ubifs_budget_space(c, &req);
	if (err) {
		kfree(dev);
		return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err) {
		kfree(dev);
		goto out_budg;
	}

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	inode = ubifs_new_inode(c, dir, mode);
	if (IS_ERR(inode)) {
		kfree(dev);
		err = PTR_ERR(inode);
		goto out_fname;
	}

	init_special_inode(inode, inode->i_mode, rdev);
	inode->i_size = ubifs_inode(inode)->ui_size = devlen;
	ui = ubifs_inode(inode);
	ui->data = dev;
	ui->data_len = devlen;

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&dir_ui->ui_mutex);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	insert_inode_hash(inode);
	d_instantiate(dentry, inode);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
			 const char *symname)
{
	struct inode *inode;
	struct ubifs_inode *ui;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	int err, len = strlen(symname);
	int sz_change = CALC_DENT_SIZE(len);
	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
	struct fscrypt_symlink_data *sd = NULL;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.new_ino_d = ALIGN(len, 8),
					.dirtied_ino = 1 };
	struct fscrypt_name nm;

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err)
			goto out_budg;

		if (!fscrypt_has_encryption_key(dir)) {
			err = -EPERM;
			goto out_budg;
		}

		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
				sizeof(struct fscrypt_symlink_data));
	}

	/*
	 * Budget request settings: new inode, new direntry and changing parent
	 * directory inode.
	 */

	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
		symname, dir->i_ino);

	if (disk_link.len > UBIFS_MAX_INO_DATA)
		return -ENAMETOOLONG;

	err = ubifs_budget_space(c, &req);
	if (err)
		return err;

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fname;
	}

	ui = ubifs_inode(inode);
	ui->data = kmalloc(disk_link.len, GFP_NOFS);
	if (!ui->data) {
		err = -ENOMEM;
		goto out_inode;
	}

	if (ubifs_crypt_is_encrypted(dir)) {
		struct qstr istr = QSTR_INIT(symname, len);
		struct fscrypt_str ostr;

		sd = kzalloc(disk_link.len, GFP_NOFS);
		if (!sd) {
			err = -ENOMEM;
			goto out_inode;
		}

		ostr.name = sd->encrypted_path;
		ostr.len = disk_link.len;

		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
		if (err) {
			kfree(sd);
			goto out_inode;
		}

		sd->len = cpu_to_le16(ostr.len);
		disk_link.name = (char *)sd;
	} else {
		inode->i_link = ui->data;
	}

	memcpy(ui->data, disk_link.name, disk_link.len);
	((char *)ui->data)[disk_link.len - 1] = '\0';

	/*
	 * The terminating zero byte is not written to the flash media and it
	 * is put just to make later in-memory string processing simpler. Thus,
	 * data length is @len, not @len + %1.
	 */
	ui->data_len = disk_link.len - 1;
	inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&dir_ui->ui_mutex);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	insert_inode_hash(inode);
	d_instantiate(dentry, inode);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

/**
 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
 * @inode1: first inode
 * @inode2: second inode
 * @inode3: third inode
 * @inode4: fouth inode
 *
 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
 * @inode2 whereas @inode3 and @inode4 may be %NULL.
 *
 * We do not implement any tricks to guarantee strict lock ordering, because
 * VFS has already done it for us on the @i_mutex. So this is just a simple
 * wrapper function.
 */
static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
			  struct inode *inode3, struct inode *inode4)
{
	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
	if (inode2 != inode1)
		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
	if (inode3)
		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
	if (inode4)
		mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
}

/**
 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
 * @inode1: first inode
 * @inode2: second inode
 * @inode3: third inode
 * @inode4: fouth inode
 */
static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
			    struct inode *inode3, struct inode *inode4)
{
	if (inode4)
		mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
	if (inode3)
		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
	if (inode1 != inode2)
		mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
}

static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
		     struct inode *new_dir, struct dentry *new_dentry,
		     unsigned int flags)
{
	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
	struct inode *old_inode = d_inode(old_dentry);
	struct inode *new_inode = d_inode(new_dentry);
	struct inode *whiteout = NULL;
	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
	struct ubifs_inode *whiteout_ui = NULL;
	int err, release, sync = 0, move = (new_dir != old_dir);
	int is_dir = S_ISDIR(old_inode->i_mode);
	int unlink = !!new_inode, new_sz, old_sz;
	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
					.dirtied_ino = 3 };
	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
	struct timespec time;
	unsigned int uninitialized_var(saved_nlink);
	struct fscrypt_name old_nm, new_nm;

	/*
	 * Budget request settings: deletion direntry, new direntry, removing
	 * the old inode, and changing old and new parent directory inodes.
	 *
	 * However, this operation also marks the target inode as dirty and
	 * does not write it, so we allocate budget for the target inode
	 * separately.
	 */

	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
		old_dentry, old_inode->i_ino, old_dir->i_ino,
		new_dentry, new_dir->i_ino, flags);

	if (unlink)
		ubifs_assert(inode_is_locked(new_inode));

	if (old_dir != new_dir) {
		if (ubifs_crypt_is_encrypted(new_dir) &&
		    !fscrypt_has_permitted_context(new_dir, old_inode))
			return -EPERM;
	}

	if (unlink && is_dir) {
		err = ubifs_check_dir_empty(new_inode);
		if (err)
			return err;
	}

	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
	if (err)
		return err;

	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
	if (err) {
		fscrypt_free_filename(&old_nm);
		return err;
	}

	new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
	old_sz = CALC_DENT_SIZE(fname_len(&old_nm));

	err = ubifs_budget_space(c, &req);
	if (err) {
		fscrypt_free_filename(&old_nm);
		fscrypt_free_filename(&new_nm);
		return err;
	}
	err = ubifs_budget_space(c, &ino_req);
	if (err) {
		fscrypt_free_filename(&old_nm);
		fscrypt_free_filename(&new_nm);
		ubifs_release_budget(c, &req);
		return err;
	}

	if (flags & RENAME_WHITEOUT) {
		union ubifs_dev_desc *dev = NULL;

		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
		if (!dev) {
			err = -ENOMEM;
			goto out_release;
		}

		err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
		if (err) {
			kfree(dev);
			goto out_release;
		}

		whiteout->i_state |= I_LINKABLE;
		whiteout_ui = ubifs_inode(whiteout);
		whiteout_ui->data = dev;
		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
		ubifs_assert(!whiteout_ui->dirty);
	}

	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);

	/*
	 * Like most other Unix systems, set the @i_ctime for inodes on a
	 * rename.
	 */
	time = current_time(old_dir);
	old_inode->i_ctime = time;

	/* We must adjust parent link count when renaming directories */
	if (is_dir) {
		if (move) {
			/*
			 * @old_dir loses a link because we are moving
			 * @old_inode to a different directory.
			 */
			drop_nlink(old_dir);
			/*
			 * @new_dir only gains a link if we are not also
			 * overwriting an existing directory.
			 */
			if (!unlink)
				inc_nlink(new_dir);
		} else {
			/*
			 * @old_inode is not moving to a different directory,
			 * but @old_dir still loses a link if we are
			 * overwriting an existing directory.
			 */
			if (unlink)
				drop_nlink(old_dir);
		}
	}

	old_dir->i_size -= old_sz;
	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
	old_dir->i_mtime = old_dir->i_ctime = time;
	new_dir->i_mtime = new_dir->i_ctime = time;

	/*
	 * And finally, if we unlinked a direntry which happened to have the
	 * same name as the moved direntry, we have to decrement @i_nlink of
	 * the unlinked inode and change its ctime.
	 */
	if (unlink) {
		/*
		 * Directories cannot have hard-links, so if this is a
		 * directory, just clear @i_nlink.
		 */
		saved_nlink = new_inode->i_nlink;
		if (is_dir)
			clear_nlink(new_inode);
		else
			drop_nlink(new_inode);
		new_inode->i_ctime = time;
	} else {
		new_dir->i_size += new_sz;
		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
	}

	/*
	 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
	 * is dirty, because this will be done later on at the end of
	 * 'ubifs_rename()'.
	 */
	if (IS_SYNC(old_inode)) {
		sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
		if (unlink && IS_SYNC(new_inode))
			sync = 1;
	}

	if (whiteout) {
		struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
				.dirtied_ino_d = \
				ALIGN(ubifs_inode(whiteout)->data_len, 8) };

		err = ubifs_budget_space(c, &wht_req);
		if (err) {
			kfree(whiteout_ui->data);
			whiteout_ui->data_len = 0;
			iput(whiteout);
			goto out_release;
		}

		inc_nlink(whiteout);
		mark_inode_dirty(whiteout);
		whiteout->i_state &= ~I_LINKABLE;
		iput(whiteout);
	}

	err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
			       new_inode, &new_nm, whiteout, sync);
	if (err)
		goto out_cancel;

	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
	ubifs_release_budget(c, &req);

	mutex_lock(&old_inode_ui->ui_mutex);
	release = old_inode_ui->dirty;
	mark_inode_dirty_sync(old_inode);
	mutex_unlock(&old_inode_ui->ui_mutex);

	if (release)
		ubifs_release_budget(c, &ino_req);
	if (IS_SYNC(old_inode))
		err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);

	fscrypt_free_filename(&old_nm);
	fscrypt_free_filename(&new_nm);
	return err;

out_cancel:
	if (unlink) {
		set_nlink(new_inode, saved_nlink);
	} else {
		new_dir->i_size -= new_sz;
		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
	}
	old_dir->i_size += old_sz;
	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
	if (is_dir) {
		if (move) {
			inc_nlink(old_dir);
			if (!unlink)
				drop_nlink(new_dir);
		} else {
			if (unlink)
				inc_nlink(old_dir);
		}
	}
	if (whiteout) {
		drop_nlink(whiteout);
		iput(whiteout);
	}
	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
out_release:
	ubifs_release_budget(c, &ino_req);
	ubifs_release_budget(c, &req);
	fscrypt_free_filename(&old_nm);
	fscrypt_free_filename(&new_nm);
	return err;
}

static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry)
{
	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
				.dirtied_ino = 2 };
	int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
	struct inode *fst_inode = d_inode(old_dentry);
	struct inode *snd_inode = d_inode(new_dentry);
	struct timespec time;
	int err;
	struct fscrypt_name fst_nm, snd_nm;

	ubifs_assert(fst_inode && snd_inode);

	if ((ubifs_crypt_is_encrypted(old_dir) ||
	    ubifs_crypt_is_encrypted(new_dir)) &&
	    (old_dir != new_dir) &&
	    (!fscrypt_has_permitted_context(new_dir, fst_inode) ||
	     !fscrypt_has_permitted_context(old_dir, snd_inode)))
		return -EPERM;

	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
	if (err)
		return err;

	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
	if (err) {
		fscrypt_free_filename(&fst_nm);
		return err;
	}

	lock_4_inodes(old_dir, new_dir, NULL, NULL);

	time = current_time(old_dir);
	fst_inode->i_ctime = time;
	snd_inode->i_ctime = time;
	old_dir->i_mtime = old_dir->i_ctime = time;
	new_dir->i_mtime = new_dir->i_ctime = time;

	if (old_dir != new_dir) {
		if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
			inc_nlink(new_dir);
			drop_nlink(old_dir);
		}
		else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
			drop_nlink(new_dir);
			inc_nlink(old_dir);
		}
	}

	err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
				snd_inode, &snd_nm, sync);

	unlock_4_inodes(old_dir, new_dir, NULL, NULL);
	ubifs_release_budget(c, &req);

	fscrypt_free_filename(&fst_nm);
	fscrypt_free_filename(&snd_nm);
	return err;
}

static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry,
			unsigned int flags)
{
	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
		return -EINVAL;

	ubifs_assert(inode_is_locked(old_dir));
	ubifs_assert(inode_is_locked(new_dir));

	if (flags & RENAME_EXCHANGE)
		return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);

	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}

int ubifs_getattr(const struct path *path, struct kstat *stat,
		  u32 request_mask, unsigned int flags)
{
	loff_t size;
	struct inode *inode = d_inode(path->dentry);
	struct ubifs_inode *ui = ubifs_inode(inode);

	mutex_lock(&ui->ui_mutex);

	if (ui->flags & UBIFS_APPEND_FL)
		stat->attributes |= STATX_ATTR_APPEND;
	if (ui->flags & UBIFS_COMPR_FL)
		stat->attributes |= STATX_ATTR_COMPRESSED;
	if (ui->flags & UBIFS_CRYPT_FL)
		stat->attributes |= STATX_ATTR_ENCRYPTED;
	if (ui->flags & UBIFS_IMMUTABLE_FL)
		stat->attributes |= STATX_ATTR_IMMUTABLE;

	stat->attributes_mask |= (STATX_ATTR_APPEND |
				STATX_ATTR_COMPRESSED |
				STATX_ATTR_ENCRYPTED |
				STATX_ATTR_IMMUTABLE);

	generic_fillattr(inode, stat);
	stat->blksize = UBIFS_BLOCK_SIZE;
	stat->size = ui->ui_size;

	/*
	 * Unfortunately, the 'stat()' system call was designed for block
	 * device based file systems, and it is not appropriate for UBIFS,
	 * because UBIFS does not have notion of "block". For example, it is
	 * difficult to tell how many block a directory takes - it actually
	 * takes less than 300 bytes, but we have to round it to block size,
	 * which introduces large mistake. This makes utilities like 'du' to
	 * report completely senseless numbers. This is the reason why UBIFS
	 * goes the same way as JFFS2 - it reports zero blocks for everything
	 * but regular files, which makes more sense than reporting completely
	 * wrong sizes.
	 */
	if (S_ISREG(inode->i_mode)) {
		size = ui->xattr_size;
		size += stat->size;
		size = ALIGN(size, UBIFS_BLOCK_SIZE);
		/*
		 * Note, user-space expects 512-byte blocks count irrespectively
		 * of what was reported in @stat->size.
		 */
		stat->blocks = size >> 9;
	} else
		stat->blocks = 0;
	mutex_unlock(&ui->ui_mutex);
	return 0;
}

static int ubifs_dir_open(struct inode *dir, struct file *file)
{
	if (ubifs_crypt_is_encrypted(dir))
		return fscrypt_get_encryption_info(dir) ? -EACCES : 0;

	return 0;
}

const struct inode_operations ubifs_dir_inode_operations = {
	.lookup      = ubifs_lookup,
	.create      = ubifs_create,
	.link        = ubifs_link,
	.symlink     = ubifs_symlink,
	.unlink      = ubifs_unlink,
	.mkdir       = ubifs_mkdir,
	.rmdir       = ubifs_rmdir,
	.mknod       = ubifs_mknod,
	.rename      = ubifs_rename,
	.setattr     = ubifs_setattr,
	.getattr     = ubifs_getattr,
	.listxattr   = ubifs_listxattr,
#ifdef CONFIG_UBIFS_ATIME_SUPPORT
	.update_time = ubifs_update_time,
#endif
	.tmpfile     = ubifs_tmpfile,
};

const struct file_operations ubifs_dir_operations = {
	.llseek         = generic_file_llseek,
	.release        = ubifs_dir_release,
	.read           = generic_read_dir,
	.iterate_shared = ubifs_readdir,
	.fsync          = ubifs_fsync,
	.unlocked_ioctl = ubifs_ioctl,
	.open		= ubifs_dir_open,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = ubifs_compat_ioctl,
#endif
};